Transformer Superconducting Transformers

In fact, with few exceptions [24], the resistance of TES is very low and the matching to a conventional FET amplifier is impossible. A SQUID amplifier (see Section 14.5) coupled to the TES by a superconducting transformer is the natural solution as schematically shown in Fig. 15.4. 

SOME EXPERIMENTS RELATING TO THE LAYOUT OF SUPERCONDUCTING TRANSFORMERS... 

Some Experiments Relating to the Layout of Superconducting Transformers... 

For the same primary and secondary currents and voltages /i, A, C/i, and U2 and equal magnetizing currents as used in conventional transformers, the number of turns of the windings, flux densities, and current densities of superconducting transformers without iron cores can be calculated from (1), (2), and (3), respectively. 

The principles involved in controlling the shielding of a conductor led to the development of the superconducting transformer. In this case, the shield is placed between the... 

In addition, it transforms like a two-fermion wave function under rotations in position and spin space and nnder gauge transformations. The transformation properties yield a general classification scheme for the superconducting order parameter which is represented by a 2 x 2-matrix in (psendo-)spin space. It can be decomposed into an antisymmetric (s) and a symmetric (r) contribution according to 2l(k) = 2lj(k) - - f fk) with... 

Tests were performed on superconducting transformers which indicated that ideal lossless transformers could be utilized for high-current applications. 

One solution to this difficulty, which is finding considerable application, uses a transformer located in the cryostat. Low currents efficiently conducted into the cryostat are stepped up in magnitude as needed. In superconducting circuits where no steady loss of power is involved, a normal transformer with suitable modification performs quite satisfactorily as a dc device. The above restriction of zero power loss is enforced by the environment so that it constitutes no real limitation to the transformer. Thedc transformer affords a method of obtaining currents of hundreds and even thousands of amperes at cryogenic temperatures. These currents are easily controlled through the primary circuit resistance located externally. When operated in a dc manner there are no losses associated with the transformer core. It is the purpose of this paper to briefly outline the operating principle of a dc transformer and to illustrate several applications. 

This doughnut has the hole stuffed with expensive items such as a transformer, superconducting coils and a lithium blanket on the exterior it has the start up injectors. An expression for Vc (empirically derived from many Tokamak conceptual designs, e.g. from those considered in Schmitter s lecture) is Vc = 7U (2 P)2 10a = 4 A (10 tz A a )... 

Fig. 3. A block diagram schematic representation of a Fourier transform nmr spectrometer, ie, a superconducting magnetic resonance system.

Uranium metal is weaMy paramagnetic, with a magnetic susceptibility of 1.740 X 10 A/g at 20°C, and 1.804 x 10 A/g (A = 10 emu) at 350°C (51). Uranium is a relatively poor electrical conductor. Superconductivity has been observed in a-uranium, with the value of the superconducting temperature, being pressure-dependent. This was shown to be a result of the fact that there are actually three transformations within a-uranium (37,52). 

Pure barium is a silvery-white metal, although contamination with nitrogen produces a yellowish color. The metal is relatively soft and ductile and may be worked readily. It is fairly volatile (though less so than magnesium), and this property is used to advantage in commercial production. Barium has a bcc crystal stmcture at atmospheric pressure, but undergoes soHd-state phase transformations at high pressures (2,3). Because of such transformations, barium exhibits pressure-induced superconductivity at sufftciendy low temperatures (4,5). 

Under pressure black phosphorus transforms first to a modification that corresponds to gray arsenic. At an even higher pressure this is converted to the a-polonium structure. Then follows a hexagonal-primitive structure, which has also been observed for silicon under pressure (p. 122), but that hardly ever occurs otherwise. Above 262 GPa phosphorus is body-centered cubic this modification becomes superconducting below 22 K.. 

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