DC performance and AC loss of sub-size MgB2 CICC conductor for fusion magnet application

2022 ◽  
Author(s):  
Peng Gao ◽  
Yuxiang He ◽  
Hongjun Ma ◽  
V.A. Anvar ◽  
Jianfeng Huang ◽  
...  

Abstract Given the low price and relatively high transition temperature (39 K) of MgB2 conductor, MgB2-based superconductors are a potential candidate for the lower field fusion coils, such as Poloidal Field (PF) coils, Correction Coils (CC) and Feeders. However, to date, the application of MgB2 is limited to demonstrators in a low magnetic field of up to 5 T and at temperatures of up to 10 to 20 K, relying on cryogen-free, helium gas or liquid hydrogen cooling, which significantly reduce the cost of cryogenic systems. To demonstrate the feasibility and performance verification of large size MgB2 PF conductors based on ITER and CFETR requirements, a 4th-stage subsize MgB2 Cable-In-Conduit Conductor (CICC) cable sample is made at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). The CICC contains 96 in-situ MgB2 superconducting wires, manufactured by Western Superconducting Technology Ltd. (WST) and 48 copper wires. The critical current of the sub-size cables and MgB2 witness wires are examined with different background magnetic fields at 4.2 K. In addition, the AC loss is measured utilizing magnetization and calorimetric methods. To further clarify the influence of electromagnetic force on the AC loss performance, the cable sample is pressed transversely at room temperature and then inserted into a dipole magnet for AC loss measurement at 4.2 K. The critical current at 4.2 K of the subsize MgB2 CICC cable shows 20% degradation compared to the witness wires at 2 T background magnetic field. However, no further critical current degradation is visible during ramping up and down the magnetic field. The coupling loss time constant for 1 T background magnetic field amounts to 480 ms. No significant effect of the applied transverse stress on the coupling loss is observed between 0 and 10 MPa.

Cryogenics ◽  
2018 ◽  
Vol 94 ◽  
pp. 1-4 ◽  
Author(s):  
Wei Chen ◽  
Haiyang Zhang ◽  
Yong Chen ◽  
Xinsheng Yang ◽  
Yong Zhang ◽  
...  

2013 ◽  
Vol 278-280 ◽  
pp. 117-120
Author(s):  
Jin Kyu Kim ◽  
Seung Bok Choi

This paper proposes a novel type of tactile device using magnetorheological (MR) fluid which can be applied in minimally invasive surgery (MIS) robotic system. The remarkable feature of rheological properties of MR fluid by the intensity of the magnetic field makes this potential candidate of the tactile device. As the first step, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Secondly, an appropriate size of the tactile device is designed and manufactured base on magnetic analysis. The final step of this study is to measure the repulsive forces of dividing 5 areas in the tactile device.


1991 ◽  
Vol 58 (11) ◽  
pp. 1205-1207 ◽  
Author(s):  
R. H. Ono ◽  
L. F. Goodrich ◽  
J. A. Beall ◽  
M. E. Johansson ◽  
C. D. Reintsema

1977 ◽  
Vol 17 (1) ◽  
pp. 93-103 ◽  
Author(s):  
N. F. Cramer

The parametric excitation of slow, intermediate (Alfvén) and fast magneto-acoustic waves by a modulated spatially non-uniform magnetic field in a plasma with a finite ratio of gas pressure to magnetic pressure is considered. The waves are excited in pairs, either pairs of the same mode, or a pair of different modes. The growth rates of the instabilities are calculated and compared with the known result for the Alfvén wave in a zero gas pressure plasma. The only waves that are found not to be excited are the slow plus fast wave pair, and the intermediate plus slow or fast wave pair (unless the waves have a component of propagation direction perpendicular to both the background magnetic field and the direction of non-uniformity of the field).


1990 ◽  
Vol 44 (2) ◽  
pp. 361-375 ◽  
Author(s):  
Andrew N. Wright

In a cold plasma the wave equation for solely compressional magnetic field perturbations appears to decouple in any surface orthogonal to the background magnetic field. However, the compressional fields in any two of these surfaces are related to each other by the condition that the perturbation field b be divergence-free. Hence the wave equations in these surfaces are not truly decoupled from one another. If the two solutions happen to be ‘matched’ (i.e. V.b = 0) then the medium may execute a solely compressional oscillation. If the two solutions are unmatched then transverse fields must evolve. We consider two classes of compressional solutions and derive a set of criteria for when the medium will be able to support pure compressional field oscillations. These criteria relate to the geometry of the magnetic field and the plasma density distribution. We present the conditions in such a manner that it is easy to see if a given magnetoplasma is able to executive either of the compressional solutions we investigate.


2018 ◽  
Vol 33 (25) ◽  
pp. 1850144
Author(s):  
Maryam Gholizadeh Arashti ◽  
Majid Dehghani

The Schwinger effect in the presence of instantons and background magnetic field was considered to study the dependence of critical electric field on instanton density and magnetic field using AdS/CFT conjecture. The gravity side is the near horizon limit of D3[Formula: see text]D(−[Formula: see text]1) background with electric and magnetic fields on the brane. Our approach is based on the potential analysis for particle–antiparticle pair at zero and finite temperatures, where the zero temperature case is a semi-confining theory. We find that presence of instantons suppresses the pair creation effect, similar to a background magnetic field. Then, the production rate will be obtained numerically using the expectation value of circular Wilson loop. The obtained production rate in a magnetic field is in agreement with previous results.


Cryogenics ◽  
1993 ◽  
Vol 33 (3) ◽  
pp. 256-260 ◽  
Author(s):  
T.L. Francavilla ◽  
R.L. Meng ◽  
P. Hor ◽  
C.W. Chu ◽  
J.W. Ekin ◽  
...  

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