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Force Field. No, Really

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  • by Adam Rightmann (609216) on Monday June 09, 2003 @08:50AM (#6149064)
    Good people, I have copied the Brookhave Press Release below, in case of Slashdotting of the server, of just in case you with to save our goverment a few nickels in bandwidth cost, nickels that might be better used to spread freedom, and democracy throughout the world.

    Brookhaven Lab and Argonne Lab Scientists Invent a Plasma Valve

    UPTON, NY â" Scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and Argonne National Laboratory have received U.S. patent number 6,528,948 for a device that shuts off airflow into a vacuum about one million times faster than mechanical valves or shutters that are currently in use. The new device, called a plasma valve, was developed through research funded by DOEâ(TM)s Office of Basic Energy Sciences in the Office of Science.

    In synchrotron light sources, other particle accelerators, and various other scientific instruments, where plasma valves can be put to use, a vacuum allows very high-energy electron beams to circulate in rings for hours. These electron beams interact with magnetic fields to generate x-rays, ultraviolet light, and other forms of radiation that travel unimpeded through beam lines used for experiments. When the vacuum is breached, air moves in with great force, the electron beam loses confinement, and its energy is deposited on vacuum walls. The faster the breach can be contained, the less damage there will be to the ring, beam lines, and the experiments that use those beam lines.

    The need for a fast valve at Argonneâ(TM)s Advanced Photon Source led Argonne engineers to explore the potential use of plasma arcs previously developed for electron welding guns. The Argonne team â" Sushil Sharma, John Noonan, Elbio Rotela, and Ali Khounsary â" joined Ady Hershcovitch from Brookhaven to develop the plasma valve.

    Hershcovitch explained the advantages of the plasma valve: "Unlike traditional valves, a plasma valve has no moving parts, does not require much maintenance, and establishes a vacuum-air separation much faster. Also, it is completely nondestructive. In contrast, existing ultra-fast valves and shutters can cause damage to machinery when triggered."

    When activated, the plasma valve is composed of an ionized gas, or a gas with charged particles confined by electric and magnetic fields, that fills an airtight aperture. When the plasma reaches certain temperature and density parameters, it separates atmospheric pressure from a vacuum, which must be devoid of pressure.

    When a vacuum is breached, a plasma arc is ignited in less than one nanosecond inside the plasma valve. The valve's outer structure is comprised of a hollow, water-cooled copper cylinder located between three cathodes and a hollow anode ring at the opposite end of the cylinder.

    At 15,000 degrees Celsius (27,032 degrees Fahrenheit), the plasma valve is about 50 times hotter than room temperature when measured in degrees Kelvin. This intense heat makes the ionized atoms and molecules move around and collide with air molecules so rapidly that the ions block any air molecules that might pass through the plasma valve.

    Researchers from around the world study a wide variety of materials at light sources such as the Advanced Photon Source at Argonne and the National Synchrotron Light Source at

    Brookhaven. For example, they use their bright beams of light to examine the minute details of computer chips to make more efficient computers, decipher the structures of viruses to work on developing new pharmaceuticals, investigate magnetic materials to make better recording devices, and study corrosion to develop new methods for its prevention.

  • by BabyDave (575083) on Monday June 09, 2003 @08:55AM (#6149109)

    Room temperature is around 290 Kelvin (about 25 degrees Celsius, or 77 Fahrenheit). Remember, 0 Kelvin is absolute zero - -273.something degrees C.

  • by BlueTooth (102363) on Monday June 09, 2003 @08:56AM (#6149124) Homepage
    15,000 / 50 = 300 kelvin

    300 kelvin = 26.85 C = 80.33 F
    [Temperature Conversion Page [nasa.gov]]

    So, about 50 times room temp.
  • by aug24 (38229) on Monday June 09, 2003 @08:57AM (#6149130) Homepage
    Huh?

    15,000 over 50 is 300.

    300 Kelvin is about 26 Celcius, 80 Fahrenheit.

    Does that help?

    J.

  • by PhxBlue (562201) on Monday June 09, 2003 @08:59AM (#6149146) Homepage Journal

    It's not as bad as you think - 300K = 27C = about 77F.

  • Plasma jargon (Score:4, Informative)

    by buckhead_buddy (186384) on Monday June 09, 2003 @09:04AM (#6149198)
    To keep all of the vampires and blood drive workers* from getting too anxious, the plasma this article refers to is not a component of blood (medical jargon). This other plasma (physics jargon) is matter that has been charged with so much energy it begins exhibiting characteristics of a liquid rather than a gas.

    *After seeing some of the workers running our corporate guilt-a-thon, I suspect this may be redundant.
  • by lingqi (577227) on Monday June 09, 2003 @09:09AM (#6149237) Journal
    i know you are trying to be funny, but realistically, the amount of energy a high-temperature "thing" contains can be a lot less than you think.

    for example, some ions trapped by the earth's magnetic field goes up to some 14 MILLION kelvins (notice it's hotter than anywhere on, around, or inside the sun). However, as there are maybe one or two such high-temperature particles per cubic centimeter, you will still freeze to death standing (erm, floating) in the middle of it.

    just a pedantic monday morning, i guess. I'll stop now.
  • by mnmn (145599) on Monday June 09, 2003 @09:14AM (#6149271) Homepage

    15,000 is a lot more than 50 times room temp. Assuming the room temperature is 26 degrees, thats 26+275 degrees above absolute zero, around 300 kelvins. I think the writer meant 500 times room temperature. I dont think plasma is 1500 kelvins.
  • It's a BULLETIN (Score:5, Informative)

    by devphil (51341) on Monday June 09, 2003 @09:20AM (#6149322) Homepage


    It's supposed to be short. That's the whole point of the online AIP: short summaries of articles.

    Why the poster linked to it instead of to a full published article, I don't know. Perhaps a full published writeup hasn't been made yet. Perhaps the poster thought that short sound bites are all that the /. crowd has attention for.

  • Re:Torps (Score:2, Informative)

    by crawling_chaos (23007) on Monday June 09, 2003 @09:21AM (#6149333) Homepage
    That's girly stuff. What I want to know is will it let me tool around inside a red giant looking for a jump point. That's a force field!

    A reference [amazon.com] for the confused.

  • by boogy nightmare (207669) on Monday June 09, 2003 @09:25AM (#6149356) Homepage
    um 300 * 50 =15,000 not 1500

    S
  • by bwohlgemuth (182897) <bwohlgemuth@gmai l . com> on Monday June 09, 2003 @09:29AM (#6149394) Homepage
    Umm...already done?

    Untima® 150 Plasma Welding System. [thermadyne.com]

  • Temperature != Heat (Score:5, Informative)

    by EvilTwinSkippy (112490) <yoda&etoyoc,com> on Monday June 09, 2003 @09:34AM (#6149431) Homepage Journal
    Remember folks, temperature is not the same thing as heat. 15,000 Kelvin that's a few molecule's thick won't damage your finger. The thermal mass of your finger would snuff it out lickety split.

    Now, the high voltage shock might give you pause before touching it again though...

  • by EvilTwinSkippy (112490) <yoda&etoyoc,com> on Monday June 09, 2003 @09:43AM (#6149499) Homepage Journal
    It's not really blocking "pressure" it's making it worth every molecule's while to go the other way. Think of it like a Rent-A-Cop with a velvet rope. Neither the velvet rope nor the Rent-A-Cop would stop a raging mob of 100 people walking straight into it.

    But, the Rent-A-Cop and his/her rope will "kindly" deflect any stray party goers that encounter it. Since you are repelling individual particles at a time, the physics are much different.

  • by KDan (90353) on Monday June 09, 2003 @09:45AM (#6149518) Homepage
    The parent is absolutely correct (at least in the content :-P). It's a volume of very hot gas enclosed in an electromagnetic field. Nothing spectacular about this, and still requires an enclosing apparatus (rather than, say, generating a forcefield around the apparatus).

    This is an advance in technology, for sure - it's a very fast valve. But there's no physics breakthrough involved. It's just an application of an old theory to an old problem, made possible by advances in technological expertise and practice. It's a clever hack but it's not a force field.

    Daniel
  • by KDan (90353) on Monday June 09, 2003 @09:56AM (#6149627) Homepage
    I did a physics masters and I never heard anyone declare that you can't say "degrees Kelvin". In fact, I must have said it myself quite a few times. Both ways of saying it are acceptable as far as I'm aware.

    Daniel
  • by djward (251728) on Monday June 09, 2003 @09:58AM (#6149649)
    Well, considering the air molecules are still colliding with *something*, namely the force field, the air friction would still be there...
  • by aimless (311570) on Monday June 09, 2003 @02:17PM (#6152507)
    And it IS Awesome!

    I worked on the pre-cursor to the plasma valve at BNL, the Vaunted "Plasma Window" (ooooh, ahhh)

    The thing really is incredible, and yes, I accepted the project because I read the description, and went..."Holy C*ap! That is just like the shuttle bay!" And it is, well...if the shuttle bay were ~4-6mm in diameter =)

    And about the 15K Kelvin thing, yes plasmas do get that hot, but lets get real here, the thing is tiny...I bet the lights above your head get just as hot in the middle of their plasmas.

    Anyway, the project I worked on was very robust and partially scaleable, just would require a boatload of power. It was very "loud" but not "noisy" as we could put very sensitive equipment right next to it and there would be no interference (you physics types should get this) and when you take a collimated beam of light...in one case a green laser, it will shine clear through it with next to no loss, which is a huge improvement over any other method of separating Atmosphere from Vacuum.

    Mind you, this would be only the first stage in a series of differential pumping to get down to UHVacuum.

    Gratz to Ady, he is one helluv a guy!

    -Chris
  • by Anonymous Coward on Monday June 09, 2003 @02:52PM (#6152971)
    This isn't something where you just throw up some copper ring and it forms some plasma between it. It is something that works because you are in a vacuum to start with, so yes the plasma has to be completely enclosed in the "magnetic/copper thingamabob." You can't have two back to back with a vacuum in between, and you can't have it operate like a Star Trek brig door. Maybe if your brig was a vacuum chamber, it might keep the air out.

    This operates like a self-sealing tire, where you put goop in the tire so that when you get a puncture the goop fills the hole as the air tries to push it out. Likewise, you cannot just throw up a ring of rubber and have some goop-field now keeping air from passing through.

    The /. title is certainly misleading. I haven't worked through all the comments yet, but there are already plenty of Star Trek force field comments. I'm sure someone will post about how you can make a light sabre using this. The same damn thing happens in at least one story every week where all the Star Trek and Star Wars advocates don't let little things like science or reality dampen their zeal in proclaiming how we are almost technologically there.

  • Re:Scale? (Score:3, Informative)

    by jpatters (883) on Monday June 09, 2003 @04:46PM (#6154347)
    Your comment is quite silly. The entire sentence, from the article, is:

    At 15,000 degrees Celsius (27,032 degrees Fahrenheit), the plasma valve is about 50 times hotter than room temperature when measured in degrees Kelvin.

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