Superconductivity Centennial
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Anyway, back to the MRI machines ...they're still using liquid-helium-cooled superconducting Nb-Ti alloy windings in the magnets. I take perverse pleasure in that, after ail that talk back in the '80s about how those blankety-blank oxide ceramic superconductors were going to do this and they were going to do that. Of course, they are taking over in some T.G. Berlincourt areas. You can make pretty good, small-size oxide supermagnets now, but you hâve to protect them from corrosive attack, and you can put them through only a certain Editor's Note: The following is an adaptation of a présentation made at the Gordon number of thermal cycles before you run Research Conférence on Superconducting Films, Tilton, New Hampshire, July 20, into trouble. 1989. The prédictions in this speech, both fanciful and serious, are those of the Aside from little research magnets, the author and do not represent any officiai position of the Department of Défense. first real supermagnet application for the Moreover, in his irreverent treatment of science, technology, industry, politics, acoxides was for gyrotron microwave and tivism, ethnicity, gender, and locale, his professed intention is only to entertain and millimeter wave gênerating tubes. They not to offend. appeared first in radar sets around the turn of the century. As power levels were raised, they were very useful for heating plasmas in controlled thermonuclearreactorexperiWell, hère it is, the year 2011, and we're ail différent directions. Afterwards, you ments. With still higher power, they could hère to celebrate the lOOth anniversary of undergo some superconducting quantum be useful for anti-aircraft, anti-missile, and the discovery of superconductivity. The arinterférence device (SQUID) diagnostics anti-satellite applications, but there's not rivai of this centennial means, one way or which sensé the magnetic fields that émamuch call for that sort of thing thèse days. another, I've now had a hand in supercon- nate from the heart and the brain. The ductivity for 61 years. Actually, at the âge of magnetocardiography scan détermines if Of course, the oxides are pretty widely 85 it's a pleasure to be hère at ail. your pump is still functioning according to used today for sensors, ail the way from de magnetic fields to radio frequency, to miBut I wouldn't be, were it not for médical specs. And the magnetoencephalography crowave, to millimeter wave, to infrared. magnetic résonance imaging, or MRI. Pro- section checks out your brain function. I gress in the performance of those MRI im- had a little problem on that one and a few There was a real battle between the oxides and the semiconductors for the infraagers has been really spectacular. We were others, and so they shunted me over to rework, but l'm O.K. now. The way I feel, I lucky to get three millimeters resolution red rôle back in the '90s. The oxides think they replaced a few more parts won—not that their performance is that when they first came into use back in the though. In fact, it's getting so I can't even '80s. Now th
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