Superconducting thin-film absolute field magnetometer

We report on the design of an absolute field magnetometer being developed to measure the ultra-low magnetic fields (<10–7 Gauss) produced for the Gravity Probe B Relativity Mission. The hysteretic behavior of fluxon motion in thin-film Niobium is used to devise a superconducting thin-film fluxgate magnetometer. Comparisons with conventional fluxgate and SQUID systems will be discussed. (Research supported by NASA, contract number NAS8-39225)