A device for measuring high current at cryogenic temperatures

In order to measure high current (several tens of kilo Ampere) at low temperature (down to 4.2 K), we have developed collaboration with Hitec Power Protection (Netherlands ex. Holec). This company sell the Macc+ (a low cost Direct Current Control Transformer) which measures up to 600 A (AC and DC) at 300 K. Several limitations of the standard Macc+ will be pointed out to find the adapted solutions for the different user conditions (temperature, current level and background magnetic field). With some minor modifications to the standard produce, we could place the torus sensor at low temperature and we measured up to RA in liquid helium at low field. Analysis of the behavior of the device in nonstandard conditions and experimental results will be reported. With more modifications, we could measure up to 38 kA at 4.2 K in a 0.5 T-background magnetic field.