A history of the CSIRO?s development of high temperature superconducting rf SQUIDs for TEM prospecting

Abstract

Over the past 14 years, CSIRO Industrial Physics has developed High Temperature Superconducting (HTS) SQUID (Superconducting Quantum Interference Device) sensor systems for TEM prospecting. Initially this work was done in collaboration with BHP P/L, now BHP Billiton, and some early successes were achieved. Collaboration with BHP ceased in 1998 after completion of a series of airborne trials. Interest in the rf SQUID sensor was revived in 2000, when it was successfully used to delineate targets at Falconbridge Ltd.?s Raglan, Quebec, mine site. As a result, CSIRO entered into a contract to build a ruggedised version of the SQUID sensor system for Falconbridge?s use under a rental agreement. Since September 2001, a number of CSIRO SQUID systems have been built and deployed over three continents. A local Australian firm, Outer-Rim Developments, has been licensed by CSIRO to manufacture the rf SQUID systems now called LANDTEMÔ. Technology transfer from CSIRO to Outer-Rim Developments was facilitated by Outer-Rim having a sub-contractor work within CSIRO for a number of months. In this paper, the results from some of the seminal SQUID surveys are presented and discussed. Finally a direct comparison between the noise performance of CSIRO?s HTS SQUID sensors and a Bartington flux-gate sensor is presented.