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Conference 7.286::space

Title:Space Exploration
Notice:Shuttle launch schedules, see Note 6
Moderator:PRAGMA::GRIFFIN
Created:Mon Feb 17 1986
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:974
Total number of notes:18843

259.0. "Superconductivity" by AMULET::STOLOS () Tue Feb 17 1987 16:12

    this morning on NPR it was reported that some scientist have
    made a material that becomes superconductive at liquid nitrogen
    temperatures, i think he was affiliated with the u of alabama.
    the reason i mention this is because this would bring down
    the costs of rail-gun designs anyone out there here anything more?
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259.1VINO::DZIEDZICWed Feb 18 1987 07:575
    There is a short article in AW&ST about this - I believe the
    temperature was in the area of -280 Farenheit.  This is almost
    100 degrees higher than the previous "breakthrough", which was
    also done by the same person.
    
259.2big BIG newsCACHE::MARSHALLhunting the snarkWed Feb 18 1987 10:4515
    Yes indeed, liquid nitrogen is cold enough to make it super-conducting.
    The material is also alledged to be relatively easy to make.
    
    This promises a revolution throught the entire electrical power
    industry.
    
    In power transmission alone, the savings would more than pay for
    the cost of refrigeration.
    
                                                   
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259.3How can this beBCSE::WMSONIllegitimi non carborundumWed Feb 18 1987 13:046
    Can someone please explain to me how building an entire transmission
    line refrigerated with liquid nitrogen will generate huge saveing
    in power distribution.  The logistics alone boggle the mind!
    
    				-b
    
259.4CACHE::MARSHALLhunting the snarkWed Feb 18 1987 14:5814
    re .3:
    
    The amount of energy currently lost because of resistive wires
    is much more than that needed to keep the wires in liquid nitrogen.
    
    The logistics of building the system are indeed boggling but economic
    feasability depends on how long it takes the savings to pay back
    the investment. This I do not know.                           
                                                   
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259.5VINO::KILGOREWild BillThu Feb 19 1987 09:073
    
    The first, most technically feasible and most easily paid back step
    would probably be a switch to supercooled transformers.
259.6Other UsesBCSE::WMSONIllegitimi non carborundumThu Feb 19 1987 13:3144
    Re .-1 : That sounds like a good possibility.
    
    To diverge a moment, but I will come back to the subject:
    
    Years ago, during the early UFO sighting period, I read an article
    that put forth the proposal that one explanation of how these objects
    could move as they did was that they had devised a propulsion system
    that coupled to the earth's magnetic lines of force.  This got me
    to thinking about how to do it so I began some experiments.
    
    I finally devised a method of winding a coil of wire that seemed
    to work.  In an artificial magnetic field created using the four
    magnets from an old crank telephone I was able to reduce the apparent
    weight fo the coil of wire from 400 grams to 200 grams by simply
    connecting a 6v battery to the coil.  With no artificial magnetic
    field I could suspend the coil vertically from the ceiling on a
    string and by applying and removing the voltage I could swing the
    coil in a considerable arc, at least a foot or two as I remember,
    altho' its been a long time.  The third thing I did was to take
    the same coil and mount in on the wing strut of an airplane with
    leads brought into the cabin to which a connected a milli (or micro)
    ampmeter.  In the air I found that if we were flying parallel to
    the earth's magnetic lines of force I got no meter reading but when
    we turned and flew across the lines I did in fact get a very noticable
    reading.
    
    When I got into the math of what it would take to make this idea
    produce useful work it was evident that because of the weakness
    of the earth's field that it would take enormous current thru the
    coil to even make it lift its own weight.  This in turn indicated
    the use of very heavy gauge wire and a power source that would be
    extremely heavy and clumsy.  The wieght requirements would always
    be more that the work produced meaning no useful work accomplished.
    With that I gave up on the idea, but maybe I should revive my
    research!  Practical superconductivity could be the answer.
    
    Picture a missile with such a supercooled coil around it, energized
    with enough current to substantially reduce the weight of the missile
    using a heavy ground based power source, then switching the coil
    to a closed loop where the induced currents would continue to flow
    due to the lack of resistance, at least for a time.  What would
    that do to payload capacity?
    						-b
    
259.7What's it made of?FDCV18::CURRENRick CurrenThu Feb 19 1987 18:3020
Is this 'warm' superconductivity akin to absolute zero
superconductivity in the sense that the electrons in the system act as
a single quantum-state unit. 

Anyone know the atomic composition?

Metallic?, crystalline?, conjugated double or triple covalent bonds?,
other? 

Regarding liquid nitrogen cooled power transmission:
Do folks expect to turn this particular material into commercial
technology, or is this just an intermediate step toward even higher
temperature superconductivity? 

Regarding flying saucers:
Wouldn't you have to keep pumping energy into the system to the same
extent that the system reacts to its movement through the earth's
magnetic field?  It may be efficient in terms of power loss through
resistance, but I doubt you have discovered a perpetual motion machine
that sustain itself while interacting with the rest of the universe. 
259.8AMULET::STOLOSThu Feb 19 1987 22:077
    i had thought that if superconductivity was achieved at liquid N2
    temps that there would be commercial uses since that technology
    is well established. what i'm looking forward to beside rail
    gun applications is that "maglev" rail road that has been talked
    about for so long. its so beutiful from an engineering viewpoint
    a linear induction motor with the only moving part is the train
    itself.
259.9BibliographyLDP::WEAVERLaboratory Data ProductsFri Feb 20 1987 17:489
    For more information, I suggest you read:
    
    Electronic Engineering Times, Monday, February 9, 1987, page 1
        "Josephson Junctions Go To Work At Last"
    
    Electronic Engineering Times, Monday, February 16, 1987, page 31
        "Cool Chips Superconduct At Higher Temp"
    
    						-Dave
259.10ALIEN::MCCARTHYSat Feb 21 1987 12:4629
>    Picture a missile with such a supercooled coil around it, energized
>    with enough current to substantially reduce the weight of the missile
>    using a heavy ground based power source, then switching the coil
>    to a closed loop where the induced currents would continue to flow
>    due to the lack of resistance, at least for a time.

>						          What would
>    that do to payload capacity?

	In fact, it would do surprisingly little. Most of the problem
	(for orbital use) is in achieving forward speed. other than
	avoiding buildings and getting away from the atmospheric drag
	quickly, there is no reason to launch objects destined for
	orbit straight up. If launched along the surface, one the object's
	speed exceeded orbital velocity at the surface, its orbit would
	rise on its own.

	Suppose you took an object of the weight of the space shuttle, and
	doubled its mass by adding superconductive coils which were so good
	that they made it wieghtless. It'd be easier to launch, right?
	wrong. The shuttle accelerates at about 3 Gs. Making it weightless
	would remove (in the early part of ascent only) a counterforce
	sufficient to produce 1G acceleration (by definition) from gravity,
	increasing the net force supplied by the engines to produce a 4G
	acceleration in an object that is the mass of the shuttle. However,
	it's mass is doubled, so you can expect to get 2G acceleration instead.


							-Brian
259.11brittleAMULET::STOLOSSat Feb 21 1987 14:356
    finally heard that npr report again (in a conscience state ) the
    plus side of superconductivity at liq. N2 temps were it was 20
    times less expensive than using liq. He the bad part of the material
    was that it was brittle. i wonder what would happen in a break of
    a supercondutive power line, would that sudden resistance cause
    all that current to go to heat?
259.12Mag wipes super?VMSDEV::FISHERBurns Fisher 381-1466, ZKO1-1/D42Sat Feb 21 1987 17:078
    Years ago when I first heard of superconductivity, it was said that
    the current material (niobium-tin?) would loose its super-c properties
    in the presence of a strong enough magnetic field.  In other words,
    too much current and poof!  The field strength required was implied
    to be very low.  Is this still a problem?  Are newer materials much
    less magnetic-sensitive?
    
    Burns
259.13Supersonducting magnet coils are a realityJANUS::BARKERSun Feb 22 1987 16:177
As superconducting magnets are used to generate large fields there must be
materials that superconduct in strong magnetic fields.

GE and/or Westinghouse have been working on superconducting alternators for
several years.

jb
259.14from my solid states physics textAMULET::STOLOSSun Feb 22 1987 17:3810
    reading from my intro to solid state physics, it sez if a strong
    enough mag field is applied to a superconductor it becomes normal
    and recovers its normal resistance even at temp below where it is
    a superconductor, the strenght of this critical field is also
    dependant on temp. for a given substance the field decreases as
    the temp aproaches the critical temp.  also it states that the
    critical field can be generated from the s-conductor itsself.
    the range in the book are 30gauss for Cd to 803gauss for Pb and
    830 for Ta. the book calls this a limitation to high field super
    conducting magnets.
259.15Superconductivity at Brookhaven National LaboratoriesDENTON::AMARTINAlan H. MartinSun Feb 22 1987 18:0420
During the late 70's (at least) Brookhaven Labs did research on using
Tin-Niobium for superconductive commercial transmission lines.  I am
pretty sure they had a test line set up in the woods for some distance.
(I have at least one strip of Tin-Niobium braid somewhere at home.)  Any
development of a warmer superconductor could only make the idea more
profitable, even if the original results weren't good enough.

Their Isabelle accelerator is designed to use superconductive
electromagnets.  I don't know if they ever completed building it, though.
I forget whether their AGS accelerator used superconducting magnets
or not.

They said that when a magnet would accidentally get a little too warm
(or perhaps that extra field effect mentioned in .14), it would stop
superconducting all at once (and get even hotter from all that current
whipping around in what has suddenly become a big resistor).  If there is a
proton or antiproton bean traveling through the accelerator at the time, it
flies out through the wall of the beam tube and makes the magnets and
shielding very radioactive through transmutation.  Oops.
 				/AHM
259.16Superconductivity at FermilabCHEV02::MARSHJeffrey Marsh, DTN 474-5739Fri Feb 27 1987 14:5664
    RE:  .13
       
    >As superconducting magnets are used to generate large fields there must be
    >materials that superconduct in strong magnetic fields.

    Yes indeed.  The magnets in the Tevatron ring at Fermi National Accelerator
    Laboratory (Batavia, Illinois) are superconducting.
    There are about a thousand superconducting
    dipole magnets (used to bend the particle beams into a circle) with
    field strengths of about 10 or 20 kilogauss.  The advantages of these
    over conventional magnets are:  1) Fermilab saves lots of money on its
    power bill,  2) magnets for a given field strength are smaller -- this
    allowed them to put a more powerful machine in the existing tunnel.
    
    Each magnet is cooled with liquid Helium *and* liquid Nitrogen (the
    Helium is to get them cold enough to superconduct and the Nitrogen is
    used as a heat shield to help keep them cold).  They have the largest
    liquid Nitrogen plant in the world there.
    
    RE:  .11
    
    >was that it was brittle. I wonder what would happen in a break of
    >a superconductive power line, would that sudden resistance cause
    >all that current to go to heat?
    
    Superconducting magnets are sensitive things.  Lots of things will cause
    them to suddenly loose their superconductivity (vibration, shock, etc.).
    This is called a "quench."  When this happens all the energy stored in 
    the magnetic field has to go somewhere.  It usually ends up as heat
    which vaporizes the liquid coolant.  The cooling system has to have
    special pressure relief valves.
    
    I live about two miles from the center of the Fermilab ring.  When there
    is a quench I can *hear* it from my living room.  It sounds as if someone
    *next door* has set off a CO2 fire extinguisher.
      
    RE:  .15
    
    >During the late 70's (at least) Brookhaven Labs did research on using
    >Tin-Niobium for superconductive commercial transmission lines.  I am
    ...
    >Their Isabelle accelerator is designed to use superconductive
    >electromagnets.  I don't know if they ever completed building it, though.

    The Brookhaven superconductivity project was stopped because it was
    very behind schedule and very over budget.  This caused a lot of anguish
    among particle physicists.  I'm sure if the Fermilab project had not
    been successful it would have been almost impossible to get another
    grant for a superconducting magnet project.
       
    >whipping around in what has suddenly become a big resistor).  If there is a
    >proton or antiproton bean traveling through the accelerator at the time, it
    >flies out through the wall of the beam tube and makes the magnets and
    >shielding very radioactive through transmutation.  Oops.

    True, this also happens when you "loose beam" for any other reason (for
    example, shutting the machine down for maintenance).  Nothing ever gets
    really "hot" (it would be a lot more dangerous working in a nuclear
    bomb factory).  You have to carry a continuous-reading dosimeter if
    you go into the tunnel (you also have to carry a 5-minute emergency
    oxygen supply and a "electronic canary" in case there is a leak in the
    liquid Nitrogen supply) in addition to your usual film dosimeter.  And
    you have to worry about shielding if you have to spend a long time down
    there.
259.17Which is largest?CRVAX1::KAPLOWThere is no 'N' in TURNKEYFri Feb 27 1987 17:338
>    Each magnet is cooled with liquid Helium *and* liquid Nitrogen (the
>    Helium is to get them cold enough to superconduct and the Nitrogen is
>    used as a heat shield to help keep them cold).  They have the largest
>    liquid Nitrogen plant in the world there.

        Liquid Nitrogen production is nothing that special in the
        commercial world. It was my understanding that Fermilab had the
        largest liquid Helium plant in the world. 
259.18CHEV02::MARSHJeffrey Marsh, DTN 474-5739Fri Feb 27 1987 18:144
    I may be wrong.  My understanding is that they suck the Nitrogen
    from the air and liquify it but that they buy Helium (already in
    liquid form for shipping) from some place in Texas.  I'll try to
    find out for certain.
259.19More papers on the subjectLDP::WEAVERLaboratory Data ProductsSat Feb 28 1987 14:3412
    Science News has had two articles on superconductivity, SN: 1/10/87
    p.23 and SN: 2/21/87 p.116.
    
    The most recent ends with the following paragraph referring to
    papers to be published March 2nd in _Physical Review Letters_:
    
    "But even these papers may soon be outdated.  Chu says his group
    has had a very preliminary indication that super-conductivity may
    occur at 240 degrees K.  That number, says one scientist in the
    field, `just leaves me speechless.'"
    
    						-Dave
259.20Metallopolitical aspect of superconductivityDENTON::AMARTINAlan H. MartinFri Mar 06 1987 19:115
Important advances in LN2 temperature superconductors might have an
interesting effect on the consumption of rare elements.  Consider the
defense aspects of discovering that certain strategic metals are in a lot
more demand than before, and that your stockpiles ought to be larger.
				/AHM
259.21Y-B-Cu-OAIWEST::DRAKEDave (Diskcrash) Drake 619-292-1818Sun Mar 15 1987 21:1123
    The impact of superconducting materials above the LN2 77 degree
    point will be as dramatic for the world as the effect of solid state
    technology. I have no doubt that this stuff will impact all of us
    within ten years. (Good set of articals in Science, March 6, 1987)
    One quote... page 1137 
    
    To make the new compound, yttrium oxide, barium carbonate, and copper
    oxide are heated to 1000 degC to promote a solid state reaction.
    The resulting material is then pulverized and heated again for several
    more hours. Next the powder is pressed into pellets for sintering
    in air at high temperatures.
    
    If I remember right the IBM research group in Switzerland had come
    very close to developing a Joe-Junct 370 CPU about 5 years ago,
    but management killed it due to the cost of superconducting components.
    That cost has just gone down by a factor of about 100. (10 for the
    cost of N2 vs He and 10 for the heat transfer properties of N2.)
    This might cause our loyal opposition at Big Blue to change heart.
    
    In any event these materials will find substantial use in industrial
    applications. It the critical temperature were to rise to the rumored
    room temp, then applications will spread like wild fire.
    
259.22Superconductivity at -27 degrees F.!EDEN::KLAESLasers in the jungle.Sat Mar 28 1987 16:1553
Associated Press Sat 28-MAR-1987 08:40                      Superconductivity

   Wayne State Physicists Find Superconductivity at Minus 27 Degrees

                             By TIM BOVEE
                        Associated Press Writer

   DETROIT (AP) - Physicists at Wayne State University say they have
found evidence of superconductivity at minus 27 degrees Fahrenheit,
more than 200 degrees warmer than those of recent experiments. 
   The physicists said Friday that their experiment may put within
sight the goal of 100 percent efficiency in the transmission of
electricity at room temperatures. 
   Superconductivity became a hot subject in physics with the
discovery last year in Switzerland of a new class of materials
allowing resistance-free passage of electricity at relatively high
temperatures. 
   Scientists say the technology eventually could have a wide range of
uses, from smaller, faster computers to trains that speed from city to
city floating above the rails. 
   Devices that are superconductive at room temperatures would be
cheap enough for commercial use, since they would not need complex
cooling apparatus. Even at minus 27 degrees, the devices would be
cheaper, since they could be cooled with liquid nitrogen rather than
the more expensive liquid helium, the physicists said. 
   ``We established a strong evidence that this is indeed an
indication of superconductivity at a high temperature,'' said
Juei-Teng Chen, one of the physicists who conducted the experiment.
``We think this is very important.'' 
   The phenomenon of superconductivity was once possible only at
temperatures near 459 degrees below zero on the Fahrenheit scale,
called ``absolute zero'' in physics because that is the temperature at
which all molecular motion stops. 
   The physicists said their findings are new in applying alternating
current in a superconductivity experiment, obtaining direct current as
an output, and detecting superconductivity at such high temperatures
in portions of a sample, rather than looking for it across the entire
sample, the physicists said. 
   Earlier this month, researcher Constantin Politis of Karlsruhe,
West Germany, found experimental evidence of superconductivity at 234
degrees below zero, apparently the warmest temperature at which
scientists have obtained superconductivity before the Wayne State
experiment. 
   Chen, Wayne State physicist Lowell E. Wenger and Eleftherios M.
Logothetis of Ford Motor Co. used yttrium, a rare metallic element, as
a component in the material they tested. 
   Chen said that at 27 degrees below zero, there is a channel of
superconductivity in the sample. Although the passage of electricity
across that channel is 100 percent efficient, the entire sample is not
superconductive. 
   As the temperature decreases, more of the sample becomes
superconductive, he said. 

259.23In celsius that is...JANUS::BARKERMon Mar 30 1987 09:368
For those who understand SI units better... (rounded to nearest degree)

	  F	  C
	 -27	 -33
	-459	-273
	-234	-148

jb
259.24Superconductivity and space applicationsEDEN::KLAESLasers in the jungle.Mon Mar 30 1987 10:3491
Newsgroups: sci.space
Path: decwrl!decvax!ucbvax!slb-test.CSNET!DIETZ
Subject: The Cold Rush of 1987
Posted: 28 Mar 87 18:02:00 GMT
Organization: The ARPA Internet
 
    Scientists at Wayne State University, in Michigan, have announced
the detection of superconductivity at 240 degrees K (-27 F) in a
two-phase mixture of the YBaCuO compound system.  Drs. Chen and
Wenger, in an attempt to disprove numerous results from other labs
hinting at high temperature superconductivity in the material, applied
a high-frequency alternating current to the sample and detected the
resulting DC voltage.  They are now attempting to identify and isolate
the high temperature superconducting phase.  According the Chen,
"Somebody could announce a room temperature material at any moment." 
 
    Progress has been extremely rapid. According to M. Brian Maple of
UCSD, "`Recently' in this field now means two days ago." Bell Labs
scientists have fashioned flexible ribbons and ceramic rings of the
materials, so there is evidence applications may be closer than many
believe. 
 
    The only physicists concerned about this stuff are the particle
physicists. They're afraid it will delay the SSC.  If they wait until
very strong magnets can be built, the SSC will shrink to the point
where it will fit in the LEP tunnel at CERN, and the Europeans will
beat them to the Nobel prizes again. 
 
    This is Space Digest, so I'll mention some implications for space.
I'm not sure what the effect of these discoveries will be on space
based power systems.  On the plus side, rectennas could be placed in
deserts far from cities, and perhaps highly efficient millimeter wave
transmitters and receivers could be developed, shrinking the
incremental size of the system. Fusion gets a big boost.  If very
large magnetic fields can be produced, reactors shrink and fuel
density increases.  D-He3 fuel would become preferable for use in
main-line reactor concepts, since reactor power density would be
limited by neutron wall loading, not by the physically attainable
power density in the plasma.  This is excellent news for those
contemplating lunar He3 mines. 
 
    On the minus side, more conventional power systems also get a
boost.  MHD generators like high magnetic fields (power density scales
as B**2). Conventional generators will get smaller and more efficient.
Replacing long distance transmission lines with superconductive lines
will save enough energy to put 50+ power plants in the US in
mothballs.  Practical energy storage systems will save even more. 
This could reduce the demand for new generating capacity for years. 
Earth based photovoltaic systems in deserts may be practical.  End
user efficiency will also improve, perhaps reducing the demand for
electricity.  The new technology should also reduce the price of
electricity, though, so elasticity of demand may increase consumption.
 
    Any use for this stuff *in* space?  High temperature
superconductors would be very useful in electrodynamic tethers,
inertial fusion rocket nozzles, mass drivers, railguns and energy
storage for all kinds of pulsed power systems.  Rocket powered MHD
generators could be useful for powering laser weapons and launchers. 
Does a very high magnetic field make the "MHD Fanjet" more practical? 
Can MHD systems replace turbines or pumps in conventional rockets,
increasing reliability?  Magnetic radiation shielding? Efficient
millimeter or submillimeter wave transmitters and receivers could make
beamed power useful in powering spacecraft anywhere in the Earth-Moon
system.  Compact fusion plants would be much appreciated for use on
the Moon and in space. 
 
    I'm looking forward to buying the following technotoy:  A bowl of
room temperature superconductor above which a magnetized globe is
levitated. It would make a great conversation piece for the coffee
table. 
 
    Someone made a comment about rare Earth elements being rare.  They
aren't. The average abundance of yttrium in the Earth's crust, for
example, is over twice that of lead and 60% that of copper.  There
isn't a big market for yttrium (currently maybe 50 tons are used per
year in red TV phosphors, along with assorted other uses in specialty
alloys, microwave ceramics and lasers), but should a big market
develop, I expect production will increase and costs will drop from
economies of scale (how much would iron cost if only 50 tons/year were
made?).  Monazite, a common heavy mineral rich in rare Earths that
often occurs as sand deposits in ancient river channels, is 3%
yttrium.  Yttrium metal is made by reduction of the fluoride with
calcium metal, but superconductors are made from the oxide, so this
expensive step is unnecessary. 

  "Eventually, no matter what we do there'll be artificial intelligence
   with independent goals.  It's very hard to have a machine that's a
   million times smarter than you as your slave."

	- Edward Fredkin

259.25more applicaitons studiesIMNAUT::BIROTue Mar 31 1987 10:319
    it is now possible to obtain enougth solar power with the
    superconductivity magnets to raise the orbit of an earth
    satellites to geo orbit and also to maintian it position
    without the need for external control jets
    AMSAT is looking at this as possible way to maintains
    its first Geo Communication satellite
    
    jb
    
259.26pulls itself up on lines of force?HERBIE::MARSHALLhunting the snarkWed Apr 22 1987 16:3211
    re .25:
    
    Just how would superconductive magnets be able to do that without
    external jets?
    
                                                   
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259.27sort of, but not easilyREGENT::POWERSFri Apr 24 1987 10:1218
    re .26, .25:
>                    -< pulls itself up on lines of force? >-

Well, yes, actually.  It's theoretically possible to guide a sattelite
by interactions between a magnetic field of its own and that of the earth.
Of course, while superconducting magnets will aid in solving the problem,
it's not clear that this approach will still be preferable to rockets.

One thing that seems to confuse people about this superconducting
thing is the idea that a superconducting ring will keep carrying
current forever.  Well, it will if nobody ever tries to extract work
from it, but you can only get out what you put in.  You can't expect
to charge up a superconducting ring, launch it into space, and have that
electromagnet do work forever.  The back-emf of interacting magnetic fields
will deplete the superconducting magnet just a surely as resistance
does in normal conductors.

- tom]
259.28stabilizers; ok, but boost?HERBIE::MARSHALLhunting the snarkFri Apr 24 1987 15:0611
    re .27:
    
    I can see how magnets could align a satellite with the Earth's
    field, but I do not see how it could boost itself to a higher orbit.
    
                                                   
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259.29Magnets can produce force as well as torqueVMSDEV::FISHERBurns Fisher 381-1466, ZKO1-1/D42Fri Apr 24 1987 21:3910
    If you were right over the north magnetic pole and you turned on
    a magnet such that it was pointed straight down, you would get a
    push up (not what you want to go to a higher orbit).  I suppose
    that if you were not directly over the magnetic pole, you would
    get a force in some other direction.  Presumably, you could manage
    your vectors right by turning the magnet on and off at the right
    times and eventually get where you wanted.
    
    Burns
    
259.3057 F!!AIWEST::DRAKEDave (Diskcrash) Drake 619-292-1818Sun Apr 26 1987 03:179
    If you have any particular new information about the area of advanced
    superconductors please send mail to Joe Skillings at Maynard MA.
    MILVAX::SKILLINGS.
    
    The Sunday Times of London reported a Japanese material with a
    threshold of 14 degrees C. (about 57 F). Joe is tracking this down.
    IBM announced a SQUID made from perovskite, wires and thin films
    have now been fabricated. See Science News April 18,1987 for a picture
    of the perovskite crystal structure, page 247.
259.31From USENETEDEN::KLAESPatience, and shuffle the cards.Sun Apr 26 1987 15:4238
Newsgroups: sci.space
Path: decwrl!decvax!ucbvax!slb-test.CSNET!DIETZ
Subject: High Tc Superconductor News
Posted: 24 Apr 87 02:17:00 GMT
Organization: The ARPA Internet
  
    Panson et. al. at Westinghouse [Appl. Phys. Lett 50(16), 4/20/87]
have estimated microscopic superconductivity parameters in
La(1.8)Sr(0.2)CuO(4) and have estimated a depairing critical current
density of roughly 500,000 amperes per square centimeter at low
temperature and zero magnetic fields, although the granular samples
they actually measured were not optimized and showed lower values
(several kiloamps/cm**2).  They state that microelectronic
applications appear practical, assuming films of the stuff are stable,
while large scale high current applications (such as magnets) are less
clear at this point. 
 
    Cava et. al. at Bell Labs [Phys. Rev. Lett 58(16), 4/20/87] have
measured critical current densities of at least 1,100 amps/cm**2 in
samples of YBaCuO at 77 K and zero magnetic field, substantially
higher than in LaSrCuO at similar T/Tc (where critical current
densities about two orders of magnitude lower were measured).  This
measurement was limited by the contacting technique used to put
current through the sample.  It would be interesting to see what Jc is
for YBaCuO at liquid helium temperatures. 
 
    Workers in Japan and at Argonne National Labs have independently
formed fine flexible superconducting wires out of the materials.  The
wires are prototypes that so far have impractically low critical
current densities. 
 
    The British journal NATURE [4/16/87, page 630] had an amusing
photo of a Japanese physicist's hand holding a permanent magnet, over
which floated an 8 gram, 4 cm diameter disk of YBaCuO, levitated in
midair by the Meissner effect.  The disk had just been dunked in
liquid nitrogen.  Current density in the disk was estimated to be
about 200 amps/cm**2. 

259.32From VOGON NewsEDEN::KLAESPatience, and shuffle the cards.Mon Apr 27 1987 10:0832
 IBM - Develops superconductivity materials with wide applications

   IBM announced a development that uses the new class of superconductivity
 materials that have caused excitement among scientists around the world.
 The devices could be used for tasks such as detecting brain waves, exploring
 for oil and conducting basic scientific research, IBM said. They contain 
 special kinds of semiconductors treated with superconducting material that 
 can detect minute magnetic fields. The superconducting quantum interference
 devices, or SQUIDs, are the first devices using thin films of the new
 superconducting material, which operate at temperatures high enough to be
 of practical use, the company said. SQUIDs currently in use must be cooled
 with liquid helium, a tricky and expensive process. IBM said its new devices
 could be cooled with liquid hydrogen, which is cheaper and easier to work
 with. IBM said its invention of higher-temperature SQUIDs was an offshoot of
 its work on new kinds of integrated circuits for a future generation of 
 super-fast computers. IBM itself does not plan to produce any devices for sale
 but would be eager to license its technology to other companies that might be
 able to introduce new products within a year. 
	{The Telegraph, 17-Apr-87, p. 34}

 DEC - To sponsor PBS science series
   DEC and WQED of Pittsburgh have joined in a multimillion-dollar project to
 bring a high-quality scientific adventure series to public and commercial
 television. The new three-year series, entitled "The Infinite Voyage,"
 produced by WQED in association with the National Academy of Sciences, will
 focus on scientific exploration and discovery. The 12-episode series will be
 the first will begin to air, one program each quarter in prime time, in the 
 fall of 1987.
	{The Telegraph, 10-Apr-87, p. 26}

 <><><><><><><>   VNS Edition : 1306      Monday 27-Apr-1987   <><><><><><><>

259.33More IBMAIWEST::DRAKEDave (Diskcrash) Drake 619-292-1818Wed Apr 29 1987 01:483
    IBM put a spectacular full page ad in the Wall Street on April 27,
    1987 concerning their interest in superconducting materials. In
    the western edition it was on page 9.
259.34RE 259.32EDEN::KLAESPatience, and shuffle the cards.Thu Apr 30 1987 16:1125
 VNS COMPUTER NEWS                        

 Errata -
 From John Hainsworth:

 Concerning the following article:

 > IBM - Develops superconductivity materials with wide applications
   ...
 > ...SQUIDs currently in use must be cooled
 > with liquid helium, a tricky and expensive process. IBM said its new devices
 > could be cooled with liquid hydrogen, which is cheaper and easier to work
 > with. 

 Is the second reference perhaps to liquid nitrogen?  Liquid nitrogen is the 
 most common cryogenic coolant, and I've never heard of liquid hydrogen
 being used.

   John's correct; the article does indeed say the new coolant is liquid
 nitrogen. - TT

   DEC:  Added 11,000 people worldwide since July, including 2,500 in Mass. 
         and New Hampshire.  Most new positions were in engineering, product
	 research, and sales.  105,000 employees as of April 15.

259.35Got to be nitrogenCADSYS::RICHARDSONFri May 01 1987 13:352
    Must mean nitrogen - liquid hydorgen ought to be dangerous, like
    a hydrogen-filled Hindenburg - combines too easily with oxygen.
259.36From VOGON NewsEDEN::KLAESThe Universe is safe.Tue May 12 1987 10:4854
VNS COMPUTER NEWS:                            [Tracy Talcott, VNS Computer Desk]
==================                            [Nashua, NH, USA                 ]

 IBM - Announces breakthrough in superconductors
   IBM scientists have increased the current-carrying capacity of a new family
 of superconductors by a hundred-fold, thus overcoming perhaps the largest
 barrier to widespread use of the potentially revolutionary materials, IBM
 announced. The latest breakthrough means the materials could be used "for most
 foreseeable applications," said Praveen Chaudhari, VP for science at the IBM
 Research Laboratory in Yorktown Heights, NY. Those uses might include
 long-distance transmission of electricity, compact high-speed computers,
 smooth-riding magnetically levitated trains, and smaller magnetic imaging
 devices for medical diagnosis.
	{The Boston Globe, 11-May-87, p. 10}

   "It's very exciting," said Praveen Chuadhari, VP for science at IBM. "From a
 science point of view, what we've done is to show that, yes, the (necessary)
 current is there." Although scientists have made a series of breakthroughs in
 raising superconductors' critical temperature, they had made little progress
 until now in improving their ability to carry current. Existing materials
 could carry the same "current density" as household wiring, but that was not
 enough for most potential uses. Major companies and universities in the United
 States, Japan and elsewhere have given high priority to research on
 superconductors, which could lead to magnetically levitating, "flying" trains,
 tiny but powerful computers, and eventually nuclear fusion through magnetic
 confinement for clean, cheap, safe energy.
   IBM scientists at the company's research center in Yorktown Heights, N.Y.,
 demonstrated that superconductors were capable of carrying more than 100,000
 amperes of current per square centimeter at the temperature of liquid
 nitrogen, which is 77 degrees Kelvin or 320 degrees below zero Fahrenheit, the
 company said. That is enough current density for almost any use except
 super-compact computer chips, the company said. "I am confident given what
 we've done so far that we'll get there, too," Chuadhari said. Chuadhari said
 scientists at other laboratories would be able to duplicate IBM's results now
 that the company had shown high current densities to be possible.
   IBM said its process was different from others, but there was unusual about
 the superconducting material it used. Researchers achieved the results by
 laying a thin film of ordinary superconducting material in the form of a
 single crystal onto a surface made of another crystal. The film was deposited
 as a vapor and measured just one micron in thickness, or about one
 one-hundredth the thickness of a human hair. "The key was to crystallize the
 film so it would follow the crystal structure" of the underlying material,
 Chuadhari said. IBM discovered that current in the superconducting materials
 flows 30 times better in one direction inside the crystal than in other
 directions. That provides insight into the structure of the little-understood
 materials. The vast improvement in current density in a single crystal showed
 that the problems with current density were not in the crystals themselves,
 but probably in the boundaries between crystals, Chuadhari said. Knowing that,
 he said, gives researchers a lead on finding ways to smooth the boundaries
 between crystals.
	{AP News Wire, 11-May-87, 7:45}

 <><><><><><><>   VNS Edition : 1316     Tuesday 12-May-1987   <><><><><><><>

259.37re .35 pls elucidateAMULET::FARRINGTONstatistically anomalousTue May 12 1987 16:511
    What's dangerous about LN2 ?  Aside from the cold.
259.38Nitrogen not good to breath w/o oxygenVMSDEV::FISHERBurns Fisher 381-1466, ZKO1-1/D42Wed May 13 1987 12:5911
    .35 said that Hydrogen was dangerous (explosive), not nitrogen.
    Nitrogen, however *is* dangerous if it leaks into a closed area.
    The problem is that you can't smell it, but neither can your body
    use it to run on w/o oxygen.  Thus, you die.  A few months before
    the first shuttle launch a couple of the ground crew died in just
    this way; an area around the base of the shuttle was being purged
    with nitrogen and these guys didn't realize it.  They walked in
    and did not walk out.
    
    Burns
    
259.39Superconductivity seminar at SHRERIE::MCKINLEYThu May 21 1987 11:147
    Technical siminar by Dr. Paul Chu, University of Houston:

    			"Advances in Superconductivity"

    May 29, Shrewsbury Amphitheater; time to be announced.

259.40Latest informationENGGSG::FLISFri May 22 1987 16:3169
From:	MKTGSG::BAUSHA       22-MAY-1987 15:25
To:	ENGGSG::FLIS
Subj:	fyi

From:	JOULE::BOXTOP::BETTE "Bette Parker, 293-5213, BXB1-2/G08  22-May-1987 0835" 22-MAY-1987 09:01
To:	@[BETTE.DIS]FORUMLTN.DIS
Subj:	SHR SEMINAR 

From:	PHENIX::MEMORY::HEDIN "21-May-1987 1121" 21-MAY-1987 14:10
To:	@SEM.DIS
Subj:	"SUPERCONDUCTIVITY" SEMINAR AT SHREWSBURY -- Don't miss this unique       opportunity to hear Dr. Paul Chu speak on this topic!


                      **************************
                      * EDUCATION AND TRAINING *
                      *  STORAGE SYSTEMS EAST  *
    *******************                        ********************
    *   T E C H N I C A L    S E M I N A R      S E R I E S       *
    ***************************************************************


                **       SPECIAL, SPECIAL!!!        **



              DR. CHING-WU "PAUL" CHU, University of Houston 

        

        "S U P E R C O N D U C T I V I T Y   A B O V E   1 0 0 K"


       * Dr. Chu is the world's leading authority on high temperature
         superconductors.  He was the first scientist to synthesize
         materials that exhibited superconducting properties above
         77 degrees Kelvin.  (See article in the Business Week).



      DATE: MAY 29, 1987            PLACE:  SHREWSBURY AMPHITHEATER

                                    TIME:  1:30 - 2:30 P.M.          



      TECHNICAL HOST:  PAUL SCHMIDT, Consulting Engineer, Storage Systems,
                       Shrewsbury-Digital





To attend this seminar, please register by filling out the form below and return
it to Marianne Hedin on APOLLO::HEDIN.

********************************************************************************

             SEMINARS ARE INTENDED FOR PERMANENT DIGITAL EMPLOYEES


NAME OF SEMINAR: ____________________________________________________

YOUR NAME:___________________________________________________________

JOB TITLE: __________________________________________________________

ENET ADDRESS: _______________________________________________________
  

259.41From VOGON NewsEDEN::KLAESThe Universe is safe.Tue Jun 09 1987 09:1720
VNS TECHNOLOGY WATCH:                           [Mike Taylor, VNS Correspondent]
=====================                           [Nashua, NH, USA               ]
      
      Researchers at Hitachi Ltd. say they have developed the
      world's first optically driven superconducting switch.  The
      device operates in Temperatures up to 88K (-188C), consists of
      thin film electrodes separated by a trench in which the
      superconductive film coating is thinner than elsewhere.  Cooled 
      in liquid nitrogen, the trench becomes superconductive, and
      electrons called "Cooper pairs" can tunnel through the area
      without resistance.  Exposing the trench to light, however,
      restricts the free flow of excited electrons.  That means light 
      - either from a laser or LED - can be used to switch between on 
      and off states.  Moreover, the device's light sensitivity can
      be increased more than 10 times by covering the trench with
      photoconducting material, according to Hitachi researchers.
      {Electronics May 28, 1987}
      
  <><><><><><><>   VNS Edition : 1335     Tuesday  9-Jun-1987   <><><><><><><>

259.42it sounds like a regular photocell to me.VIDEO::OSMANtype video::user$7:[osman]eric.sixWed Jun 10 1987 11:0011
Can someone please explain what the big deal is ?

It sounds like you're talking about a photocell that only works
when it's frozen to -88 degrees.

I have one that works at 80 degrees.  What's so exciting ?

I'm sure there are some technical details that would shed some
more excitement about this.  Please explain, thanks.

/Eric
259.43My guessTALLIS::MATSUOKAMasamichi @LTN1-2/B17Wed Jun 10 1987 11:517
    
    I suppose the phenomenon makes optical interconnection of
    superconducting devices possible.  I would think some of the
    massively parallel architectures (such as Hypercube) can
    greatly benefit from such direct optical interconnects.
    
    MJM
259.44An important component in a new technology...LILAC::MKPROJREAGAN::ZOREWed Jun 10 1987 13:5531
    	I'm no expert at all in this field but I'll hazard a guess.
    First you have to understand why superconductivity itself is exciting.
    By using the technology of superconductivity, one can transmit
    electricity with virtually no loss of power.  You've heard about
    the need for more generating plants?  Well, with this technology
    we could probably close most of the plants in existance and still
    have more electricity than we could use, this because most electricity
    today is used up in transmission.  The new optical switch provides
    a non-mechanical method of switching electricity on/off.  Less
    maintenance, no friction (heat), etc..  Granted the technology of
    superconductive materials is still in its infancy, but this was
    an important step to the day when (perhaps) most electricity would
    be transmitted by super-conductive materials.  That will be a day
    to celebrate!  Why celebrate?  Because we'll have no more Seabrooks,
    Because most of the electricity generation plants could be closed
    with a resulting drop in air pollution.  Because we could build
    extreamly fast magneticly suspended trains to travel from coast
    to coast.  Because we could use electric cars more and gasoline
    cars less and that will also reduce air pollution.   
    	The whole trick is to get the temperatures at which you have
    superconductivity as high as possible so you don't have to have
    special equipment to have superconductivity.  Once you do that you
    may be able to end the use of carbon based fuels (oil, coal, wood)
    and that would indeed by a happy day for Mother Earth.  It is the birth
    of a technology which could change our lives as much as the invention
    of the internal combustion engine did.

    Thats why I think its a big deal.  :-)
    
    Rich
259.45Unfortunately, it has competition...EDEN::KLAESThe Universe is safe.Wed Jun 10 1987 15:427
    	Superconductivity IS wonderful and fantastic, but how are we
    going to keep the big oil and nuclear companies from stopping it
    in their never-ending quest for continous huge profits and inherent
    short-sightedness?    
    
    	Larry
    
259.46LDP::WEAVERLaboratory Data ProductsWed Jun 10 1987 20:046
    Re: .45
    
    Maybe because the semiconductor business is bigger?  Interesting
    question...
    
    						-Dave
259.47cat has left bagSAUTER::SAUTERJohn SauterThu Jun 11 1987 11:2318
    re: .45
    
    It's unstoppable now.  Too many people know about it, and are working
    on making it practical.  If GE refuses to use it, some small company
    will, and will start taking business away from GE.  GE (and Exxon, and
    Westinghouse, etc., etc.) all know this, and so they won't try to
    stop it--they will try to also offer products with this technology.
    
    The Japanese will probably be first to the market with products.
    They import all their oil, and this can save them plenty.  They
    also use high-speed trains.  Even ignoring the argument above, Japan,
    Inc., is bigger than the Big Energy companies, and so can't be
    suppressed by them.
    
    In 10 or 20 years the world is going to look different in ways that
    are presently very hard to predict (though that won't inhibit the
    predictors).  We live in interesting times, indeed.
        John Sauter
259.48From VOGON NewsEDEN::KLAESThe Universe is safe.Fri Jun 12 1987 09:0530
VNS COMPUTER NEWS:                            [Tracy Talcott, VNS Computer Desk]
==================                            [Nashua, NH, USA                 ]

 MIT Team - Develops superconductors using metal alloys instead of ceramics

   Gregory J. Yurek's team, which hasn't yet reported its findings in
 scientific journals, also found a way to produce the alloy ribbons so they are
 stronger, denser and more flexible than ceramic versions, which tend to be
 brittle, he said. The MIT superconductors, made from europium, barium, and
 copper, work at 90 degrees Kelvin, or about 298 degrees below zero Fahrenheit.
 Mr. Yurek said the "breakthrough" - turning the alloy into a superconducting
 oxide - was achieved last Thursday. It was disclosed Wednesday at a
 congressional committee hearing on superconductivity. Another researcher who
 testified at the hearing, C.W. Paul Chu of the University of Houston,
 disclosed that his research had observed evidence of superconductivity in one
 of the new ceramic superconductors at 360 Kelvin, or 189 degrees Fahrenheit.
 Mr. Chu's disclosure follows several recent reports by research teams of signs
 of superconductivity at nearly room temperature.
   "The stakes are too high to let superconductors go the way of the VCR," said
 Sen. David Durenberger (R., Minn.) who, with Rep. Don Ritter (R., Pa.),
 recently introduced a bill that would form a commission to develop strategies
 for commercial and defense applications of superconductors. Rep. Ritter added
 that a "coordinated-team America" approach is needed in superconductivity
 research. That may require changes in anti-trust law to allow increased
 cooperation among U.S. companies involved in the superconductor race, he said.

	{The Wall Street Journal, 12-Jun-87, p. 28}

  <><><><><><><>   VNS Edition : 1338      Friday 12-Jun-1987   <><><><><><><>

259.49For use in deep space probes...LILAC::MKPROJREAGAN::ZOREWed Jun 17 1987 12:3414
    	I was watching a show last night about the Voyager II probe
    as it went past Uranus.  The show mentioned that the temp in that
    part of the solar system was about 70K.. It occured to me that these
    breakthroughs in superconductivity could be put to use on space
    probes to this area of the solar system since the temp. is so low,
    they wouldn't need any extra cooling equipment.  These probes operate
    at very low wattage (I think the show stated that the Voyager II
    was transmitting at 25 watts) and would probably benefit in usiong
    these materials in thier construction.  All in all it was an
    interesting show and demonstrated again the agility and resourcefulness
    of the people at JPL.
    
    Rich
    
259.50Radiation, not conductionVMSDEV::FISHERBurns Fisher 381-1466, ZKO1-1/D42Wed Jun 17 1987 14:0312
    re .49:  It is not clear what it means to say that the temperature
    in a region of space is n degrees.  There is very little material
    there to *have* a temperature.  And even if the temp of hydrogen
    atoms floating around was 70K, that would have very little effect
    on a spacecraft; the dominent mode of heating/cooling is radiation.
    
    This is not to say that one could not get the temp down to
    superconducting levels with some clever spacecraft coloring, fins,
    etc.  Just to point out that things are not always as they seem.
    
    Burns
    
259.51surfaces of moons was 70KLILAC::MKPROJREAGAN::ZOREThu Jun 18 1987 09:0813
    	The show mentioned that the surface tempurature of the moons
    of Uranus was 70K, they didn't mention if this was in the sun or
    in the shade.  I just assumed that if the surface tempurature of
    the moons was 70K then the tempurature of the probe would be 70K
    too.
    	The show also mentioned that the planet had a core of molten
    rock and that most of the size was taken up by water of all things
    which had a tempurature of 4000F!  Above this was an atmosphere of
    various gases like that of Jupitor.  So the basic structure had
    3 layers: molten rock core, large layer of super heated water,
    atmosphere of gas.
    
    Rich
259.52The temp keeps getting higher!PROTO2::FISHERBurns Fisher 381-1466, ZKO1-1/D42Mon Jun 22 1987 23:5212
    A short article in the local paper last week (Saturday Nashua Telegram,
    I believe) indicated that some researchers have found a material
    that shows signs of superconductivity at around 90F!  The article
    went on to say that this is not the same as saying that it
    superconducts.  Apparently these "signs" are just a sort of screening
    that they can do.  In addition, it was only in a portion of the
    material, not the entire sample.  They have to find out what is
    different about that portion, and make larger quantities to test
    it out further.
    
    Burns
    
259.53Are you sure it's not a misprint?LILAC::MKPROJREAGAN::ZORETue Jun 23 1987 10:025
    re: .52
    	Did you mean to say 90F or was that supposed to be 90K?  There's
    a big difference you know. :-)
    
    Rich
259.54Doubt itENGINE::BUEHLER63% �r... DeadTue Jun 23 1987 12:226
  The wording of "signs of superconductivity" is becoming more and more
commonplace for really high temperature superconductivity tests.  They've
already established the presence of superconductivity in materials well
over 90K.

John
259.55From VOGON NewsEDEN::KLAESThe Universe is safe.Tue Jun 23 1987 13:3417
VNS COMPUTER NEWS:                            [Tracy Talcott, VNS Computer Desk]
==================                            [Nashua, NH, USA                 ]

 Superconductivity - Found at 90 degrees Fahrenheit, firm says

   Energy Conversion Devices Inc. said it found the evidence in a ceramic
 material. The company said it's scientists observed the Meissner effect - the
 repelling of magnetic fields by superconductors - in a sample of
 superconducting ceramic. The experiment indicated that less than 1% of the
 sample was superconducting. But ECD said it calculated the Meissner effect at
 about 10 times the strength registered previously with similar
 high-temperature superconductors.

	{The Wall Street Journal, 18-Jun-87, p. 8}

  <><><><><><><>   VNS Edition : 1344     Tuesday 23-Jun-1987   <><><><><><><>

259.56RE 259.55EDEN::KLAESThe Universe is safe.Thu Jun 25 1987 09:3416
VNS COMPUTER NEWS:                            [Tracy Talcott, VNS Computer Desk]
==================                            [Nashua, NH, USA                 ]

 Note: Dean Cromack asks, in reference to an article in VNS #1344 attributed to
	the 18-Jun-1987 WALL STREET JOURNAL, if the evidence of
	superconductivity was found at 90 degrees Fahrenheit or Kelvin. The
	article is quite clear that the temperature was Fahrenheit. Two things
	to remember: the article said they found evidence of superconductivity,
	not that they had a superconductor. Also I believe the article didn't
	mention whether or not another site has been able to reproduce their
	results. I did make a mistake, however: the article appeared on page 8
	of the June 19th edition of the JOURNAL - not the 18th mentioned in
	VNS #1344. - TT

  <><><><><><><>   VNS Edition : 1346    Thursday 25-Jun-1987   <><><><><><><>

259.57RE: .54 -- Nobel dreams...CAADC::MARSHJeffrey Marsh, DTN 474-5739Sun Jun 28 1987 03:1215
>   The wording of "signs of superconductivity" is becoming more and more
> commonplace for really high temperature superconductivity tests.  They've
> already established the presence of superconductivity in materials well
> over 90K.

Usually "signs of superconductivity" means that a sharp decrease in 
resistance was observed as the temperature was lowered.  This observation
does not necessarily mean that what you have is a superconductor.  The real
test is how the stuff behavies in a magnetic field -- the "Meissner effect"
mentioned in .55.

I'm afraid that the fame that will befall the first person to discover a
room-temperature superconductor is so tempting that many scientists are
rushing to publish even preliminary results.  Oh well, even scientists are
human.  :-)
259.58From VOGON NewsEDEN::KLAESThe Universe is safe.Tue Jun 30 1987 09:1615
VNS TECHNOLOGY WATCH:                           [Mike Taylor, VNS Correspondent]
=====================                           [Nashua, NH, USA               ]

    Kawasaki Steel Corp. has established the basic technology to
    produce superconducting wires in commercial quantities. 
    Kawasaki is using ceramic oxides of yttrium, barium, and
    copper, which act as superconductors at 93K (-356F). 
    Densities of 410 amperes per square centimeter achieved in
    tests last month showed the absence of impurities in the
    product, Kawasaki said.  Standard product wire dimensions are
    1 mm diameter and 10 meters long.
    {AW&ST June 22, 1987}
    
  <><><><><><><>   VNS Edition : 1349     Tuesday 30-Jun-1987   <><><><><><><>

259.59A Superconductivity Conference!EDEN::KLAESThe Universe is safe.Sun Jul 05 1987 14:5116
VNS Letters to the Editor:
==========================

From: Greg Opp ................................................ Maynard, MA, USA

  A reader wrote in last week inquiring about superconductivity.  A Notes
file discussion of this topic was recently started and is located at:

		ERIE::DISK$117:[GWHITTEN.PUBLIC]SC.NOTE

Regards,

Greg

  <><><><><><><>   VNS Edition : 1352      Friday  3-Jul-1987   <><><><><><><>

259.601987 SC Year in ReviewDICKNS::KLAESAll the galaxy&#039;s a stage...Mon Jan 11 1988 12:5778
VNS TECHNOLOGY WATCH:                           [Mike Taylor, VNS Correspondent]
=====================                           [Nashua, NH, USA               ]

                  Will 1988 See A 92K Superconductor IC?

       The pace of research into "high temperature" superconductivity
       showed no sign of slowing as 1987 drew a close, with labs around
       the world racing to take the next step - fabrication of
       integrated circuits.  Much work remains, but progress late in the 
       year in the development of both materials and processing
       technology is encouraging predictions that the first experimental 
       high temperature Josephson junction circuits could be fabricated
       within 12 months.

       Use of new materials has been recorded at by TRW and AT&T Bell
       Labs. TRW researchers have substituted erbium for the yttrium in
       the conventional yttrium-barium-copper oxide and wound up with a
       thin-film ceramic that they say superconducts at 92K.  This
       compares with most previously reported materials whose transition 
       temperature is about 70K. And Bell Labs reports superconductivity 
       at 77K with a variety of rare-earth oxides. Meanwhile GM has come 
       up with a processing innovation that could speed production of
       superconducting thin films.

       The TRW team reports that the surface quality of their thin film
       is already good and improving steadily. In fact, it is suitable
       for their next step, fabricating experimental Josephson junction 
       devices, says Arnold Silver, manager of superconductive
       electronics at TRW.

       Two of problems that remain are finding a way to fabricate thin
       film devices and stripline interconnects that operate up to 100
       GHz. In addition, the devices have to be fabricated on silicon, as 
       well as on GaAs or sapphire, rather than the even more exotic
       substrate materials, such as strontium titanate.

       With the Josephson junction, an even bigger limitation is the
       actual structure of the device.  One problem is its two terminal
       nature (as essentially a tunnel diode), which makes for a
       difficult input/output operation. A MOS transistor, by contrast,
       has three terminals.  "There's no simple way to have control
       lines," says Robert Dynes, director of the Bell Labs Chemistry
       Physics Research Laboratory. In addition, as current driven
       devices, the junctions have to be "drive hard, close to the
       switch point," so they are always running at high noise levels,
       he says.
       {Electronics Jan 7, 1988}

             A Fast Way To Make Superconducting Thin Films

       Researchers at General Motors Research Laboratories say they have 
       come up with a quick, inexpensive process to make and alter the
       composition of superconducting thin films.  Unlike most
       researchers, GM has turned to metallo-organic deposition.  
       Because the approach is nearly identical to standard liquid
       spin-coating photoresist techniques, and because it is done
       entirely at atmosphere pressures, the method can be accomplished
       with minimum capital investment.  This could open up the field
       for researchers at more universities and other labs with limited
       budgets.

       What's more, the technique allows composition of superconducting
       materials to be altered and made into thin films faster than
       other methods.  "If someone can out tomorrow with a material
       that is room temperature superconductor, we could have a thin
       film of that material within a week" contends GM research
       engineer Joseph Mantese. Researchers at AT&T and Purdue
       University have used the same method, but GM says it was first to 
       publish results and has filed for a patent on the technology.  

       Next is the preparation of similar films on a silicon substrate.
       The key is the development of a suitable diffusion barrier that
       will prevent silicon migration into the thin film, which can
       destroy its superconducting properties.
       {Electronics Jan 7, 1988}

  <><><><><><><>   VNS Edition : 1483      Monday 11-Jan-1988   <><><><><><><>

259.61SC Conference now on node AISVAXDICKNS::KLAESThrough the land of Mercia...Mon Mar 07 1988 14:0914
        The Superconductivity Conference is now located at node AISVAX.  
    If you already have SC, but on the old node, write this command at 
    the Notes> prompt:
    
    	MODIFY ENTRY SC/FILE=AISVAX::DISK$117:[GWHITTEN.PUBLIC]SC.NOTE
    
    	If you are new to the Conference, please write this command:
    
    	ADD ENTRY AISVAX::DISK$117:[GWHITTEN.PUBLIC]SC.NOTE

        Or press the KP7 or SELECT key to add SC to your Notebook.
                                                                       
    	Larry
        
259.62SC uses in space explorationDICKNS::KLAESIt&#039;s Bicycle Repair Man!Fri Apr 08 1988 19:3158
From: [email protected] (Eugene N. Miya)
Newsgroups: sci.space
Subject: Re: Superconductors
Date: 7 Apr 88 16:47:45 GMT
Organization: NASA Ames Research Center, Moffett Field, Calif.
 
    In article <[email protected]> [email protected] 
(Sang J. Moon) writes: 

>I may be treading a beaten path, but I would like to know what uses
>the present or future space program has for superconductors.
 
    "You are forgiven, my son..."  You are only the second request I've seen.
 
    "There are many uses..." say the people who don't really know
anything except the ruediments of superconductivity. 
 
    The uses these materials will see in space will be anything which
benefits having current flow through them:  Computers, power systems,
motors, etc.  There are still too many unknowns:  Mass production, can
you make wire?  Does this stuff fall apart through time?  Can it be
radiation hardened?  Etc. etc.  The problem is like this:  Chu's
ceramic works in LN2.  Do we start to gear up for LN2 technology (we
can, witness the ETA-10)?  Or do we wait for the promised (like AI,
fusion, and remote sensing) room temperature SC?  If we wait, it may
never appear (there are limits to these things), if we go to LN2, then
we have this obsolete stuff if room temp stuff appears.  The third
course (bureaucratic) is waiting and use existing stuff (non-SC).  I
would rather buy Genetech or minisuper stock myself than SC companies.
 
    Just too much hype in this field right now.  A good talk was given
last summer at Stanford on the promise of SC materials in the supercollider. 
 
    NASA is not specifically targeting anything to use the new
superconductors.  There is insufficient knowledge to apply them to
like or project "threatening" space missions.  On the other hand, NASA
is supposed to take risks.  It's a tradeoff.  You will notice no one
at NASA has made any of the IBM material for instance (H.S. do it,
right? ;-), and there has been only one internal meeting I am aware of
on the topic.  There's more to space than flowing electrons. 
 
    If you are willing and in able health, maybe we can make a fly-by
wire SC plane and let you be the first to test fly it ;-).  We will
try our best to prevent you from augering in.  Ooops, we forgot the
aerodynamics!  Back to the drawing board....
 
    It has been printed that research takes 20 years to see practical
applications (a figure typically printed in the 1960s, may not take
exponential growth into account).  Superconditivity will be an
interesting case to see in all of your life times. 

    From the Rock of Ages Home for Retired Hackers:
 
--eugene miya, NASA Ames Research Center, [email protected]
  "You trust the `reply' command with all those different mailers out there?"
  "Send mail, avoid follow-ups.  If enough, I'll summarize."
  {uunet,hplabs,hao,ihnp4,decwrl,allegra,tektronix}!ames!aurora!eugene

259.63Sensors, power sources, and heat shieldsDICKNS::KLAESIt&#039;s Bicycle Repair Man!Tue Apr 12 1988 10:2946
From: weltyc@nysernic (Christopher A. Welty)
Newsgroups: sci.space
Subject: Re: Superconductors
Date: 11 Apr 88 21:59:25 GMT
Organization: RPI Computer Science Dept.
 
    Superconductivity does have very exciting prospects, in and out of
space; but it is difficult to get around all the hype.  Here is what
this months NASA Tech Briefs says about what NASA is doing: 
 
    First of all there is a clear advantage to space applications, the
current superconductors can be used since space is cold enough (just
keep it away from direct sunlight...), so many of these do not need to
wait for the mythical "room temperature superconductor". 
 
    Sensors:  NASA plans to use the new ceramics to improve the
detection range of space-born sensors.  NASA Marshall  is researching
using a `superconducting quantum interference device' (SQUID) which
will be used on `deep space gravity probes'.  NASA JPL is working on
superconducting-insulating-superconducting (sounds like a Josephine
Junction) junction for atmospheric remote sensing satellites, which
would be ten times more sensitive than current models. 
 
    Power and Propulsion:  Current battery systems for the Shuttle and
other spacecraft are quite limited.  Superconducting batteries are
being ressearched at NASA Lewis for extending space missions and the
lifetimes of space probes.  Also electromagnetic launchers are
beginning to look feasible. 
 
    Space shield:  [This sounds incredible, but I don't know...]
Apparently NASA Lewis is also looking into the feasibility of a
superconducting magnet being used as a heat shield.  If the magnetic
field was intense enough, and concentrated at the front of a
reentering spacecraft, it would keep the hot, ionized gases away from
the craft. 
 
    Although we're probably all familiar with the problems that the
current superconductors have (especially current density), apparently
NASA IS working and researching this stuff for space applications.
There was no mention as to when they thought any of this would come
about, and it may very well be (although I'm not really qualified to
say) that this is all just pie in the sky kind of thinking.... 
  
    Christopher Welty  ---  Asst. Director, RPI CS Labs
    [email protected]       ...!rutgers!nysernic!weltyc

259.64SC advancements could reduce satellite sizesCLIPR::KLAESN = R*fgfpneflfifaLTue Aug 01 1989 09:2734
VNS COMPUTER NEWS:                            [Tracy Talcott, VNS Computer Desk]
==================                            [Nashua, NH, USA                 ]

    Superconductors - NASA's superconductor could shrink size of satellites

   Scientists at the National Aeronautics and Space Administration say they
 have produced a high-speed circuit using high-temperature superconductors that
 may drastically shrink the size of communications satellites and improve their
 performance. High temperature is relative where superconductors are concerned.
 The NASA circuit works at minus 320 degrees Fahrenheit. That is enough of an
 improvement, compared with past superconductors, so that researchers can cool
 the device with liquid nitrogen rather than liquid helium, which is costlier
 and more difficult to handle. Kul Bahsin, a space-electronics researcher at
 NASA's Lewis Research Center in Cleveland, said the circuit could become part
 of future generations of satellites that operate at ultrahigh frequencies,
 called K-band. These frequencies would let satellites process data at much
 faster rates and handle many more customers than conventional satellites. Mr.
 Bhasin said the superconducting circuit would enable satellite makers to
 reduce the size of certain filters from several yards in length to the size of
 a thumbnail. Size is critically important in the satellite business, because
 launch costs are so high. Smaller satellites can use smaller and less
 sensitive rockets. In addition, Mr. Bhasin said the circuit might be used in
 radar-imaging satellites to reduce the size of space antennas. The military
 uses radars satellites to track targets through clouds and at night.
 Resolution of radar antennas is related to their size, and shrinking an
 antenna could theoretically improve its ability to see small objects. Mr.
 Bhasin said the superconductor circuit was made from a material called yttrium
 barium copper oxide. He said satellite circuits could become one of the first
 applications of high-temperature superconductors.

	{The Wall Street Journal, 31-Jul-89, p. B2}

  <><><><><><><>   VNS Edition : 1871     Tuesday  1-Aug-1989   <><><><><><><>

259.65HTSSE set for launch in 199225625::KLAESAll the Universe, or nothing!Thu Jun 06 1991 09:4642
VNS TECHNOLOGY WATCH:                           [Mike Taylor, VNS Correspondent]
=====================                           [Littleton, MA, USA            ]

            High Temperature Superconductivity Space Experiment

    The Naval Research Laboratory's (NRL) high temperature superconductivity
    space experiment (HTSSE) is set to be carried as a secondary payload
    on a satellite to be launched next year on a Titan 4, according to
    George Price, a project manager.  The HTSSE will demonstrate the
    feasibility of high temperature (77K) superconducting systems in
    space by using a 200 lb cryogenic nitrogen cooled system to test
    the performance of multiple devices.  The experiment has been structured
    to leverage the US national program in high temperature superconductivity
    and focus a major portion of the effort into space applications.
    {AW&ST April 8, 1991}

                              DARPA in Space

    DARPA has about 40 advanced space technology efforts under way including:

    Infrared tunnel sensors:  Tunnel technology involves taking opposing
    semiconductors, which do not touch but still pass a tunneling
    current between them.  These sensors have about 10,000 times the
    sensitivity compared with current piezoelectric devices," Col.
    Nicastri, assistant director for space systems.  Systems using this
    technique could be sensitive enough to measure gravity waves,
    Nicastri believes.

    High-throughput computer:  Development of a high throughput space
    based super computer/parallel processor that would be only 5 in. sq.
    and capable of 40 billion operations/sec.
    {AW&ST April 8, 1991}

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259.66Request for SpeculationSWAM1::MILLER_SUFrom the land of the LLOstFri May 15 1992 00:475
    Where in the Solar System might it be most likely to find deposits
    worth mining of the rare earths used in superconductors?  I seem to
    recall that noticeable amounts of yttrium were found in lunar rocks --
    but Luna might be expected to be very Earth-like.  Will there be
    niobium mines on Mars?  Erbium prospectors in the asteroids?