Conveners
M3Or2B - AC Loss YBCO
- Milan Majoros (The Ohio State University)
- Takanobu Kiss (Kyushu University)
The second generation (2G) coated conductors are considered for applications at relatively high, 20 โ 30 K temperature, which can be achieved with an inexpensive single-stage cryocooler. Electromagnetic AC losses in 2G coils account a significant fraction of the total loss budget. It is well known that the AC loss is proportional to the superconductor filament width. However, reducing the...
In this work, segment of various HTS cables were measured for loss at high dB/dt in a rotating magnet AC loss machine. The cables types including CORC, Roebel, and TWST cables. The cable were measured in a spinning magnet calorimeter (SMC). This test device has a spinning rotor which consists of permanent magnets arranged in a Halbach array, with the sample exposed to an AC field of 0.566 T...
A no-insulation approach is now of great interest for use in magnets and coils made with YBCO coated conductor. The low inter-strand electrical resistance allows current sharing between layers of the coil, and the associated high thermal conductivity allows for thermal sharing. However, it is of interest to know what actual level of layer to layer electrical and thermal conductivity is needed...
A typical Adiabatic Demagnetization Refrigerator (ADR) has modest cooling power, on the order of a few microwatts. Thus, understanding heat loads going into and generated within the ADR is vital to its efficiency as well as the efficiency of the total cryogenic system of a spacecraft. One of the many sources of heat that effects the total cryogenic system is the parasitic heat due to AC loss...
The U.S. Air Force Research Laboratory (AFRL) facility for the measurement of alternating-current (AC) loss in superconductors at high B*dB/dt has been recently tested and calibrated for operation. The test device has a spinning rotor consisting of permanent magnets arranged in a Halbach array; which exposes samples in a stator position with a peak radial field of 0.57 T, and with high...
