The background magnet system of SSTF (Samsung Superconductor Test Facility)
for KSTAR (Korea Superconducting Tokamak Advanced Reseal ch) is now under
design. The main coil (MC) is split solenoids and the gap can be changed fr
om 0 to 750 mm, The PD of MC is 750 mm, It will be wound using a CICC (cabl
e-in-conduit conductor) designed for the central solenoid of KSTAR. The cen
tral field is 8 T at 22.5 kA when the gap is 250 mm, The ramp rate of MC is
3 T/s, A pair of blip coils will simulate (during the discharge) 1 T ampli
tude and 20 T/s rate electromagnetic disturbances expected from the KSTAR o
peration. To compensate the inductive interaction between MC and blip coils
during the discharge of the blip coils, a pair of cancellation coils is fo
reseen. Both blip and cancellation soils (BCC) ar e fed in series and gener
ate I T central field @ 7 kA and 250 mm gap, The BCC are wound with CICC an
d cooled internally and externally.