Abstract
Abstract
Superconducting transformer is a typical facility used for
inducing ultra-high current for large-scale scientific measurement
systems, such as SULTAN-facility at the Centre de Recherches en
Physique des Plasma (CRPP) in Switzerland, FRESCA-facility at CERN
in Switzerland etc. A new program has been launched at the Institute
of Plasma Physics, Chinese Academy of Sciences (ASIPP) to build a
new conductor test facility to investigate the transverse pressure
dependence of critical current of various superconducting cables
using a compact superconducting transformer and cryogenic
electromagnetic press systems. The superconducting transformer can
induce a secondary current up to 60 kA, at a background magnetic
field up to 15 T at 4.2 K. To measure the induced secondary
current at cryogenic temperature precisely, three types of NbTi
superconducting coils are designed based on the zero-flux principle
to characterize the variation of the measured current. In this
paper, the design principle of the cryogenic DC transformer and its
commissioning results in a preliminary prototype test device are
presented. The measurement results show achievements on accuracy of
±0.6% or less and nonlinearity of better than ±0.25%,
which demonstrates the feasibility of the cryogenic DC transformer
and provides a reliable technology for the secondary current
measurement of a 100 kA superconducting transformer used in the
program of Super-X test facility at ASIPP.