Field tests of the TDEM data acquisition system based on HTS SQUID magnetometer (SQUITEM).

概要

論文の詳細を見る
We report on the research and development of a TDEM data acquisition system (SQUITEM) by JOGMEC using a highly sensitive high-temperature SQUID vector magnetometer cooled by liquid nitrogen. SQUITEM meets high requirements for slew rate (6.8 mT/s), dynamic range (100 dB) and bandwidth (DC-100kHz) for metal exploration. It offers deeper penetration of depth than the conventional induction coil system because it can record the step response that decreases with time slower than the impulse response of the induction coil system.<BR>We have conducted field tests several times since 2002 in order to check performance and practicality of SQUITEM. JOGMEC has achieved stable long-term operation of all three channels, obtained good reproducibility of SQUITEM data, and good correlation between the output signals of the reference induction coils and the derivatives of the SQUITEM signals in the field tests. JOGMEC conducted the field test in February, 2005 in Marrakech-Tekna Area, Morocco where JOGMEC carried out metal exploration for the past three years. The SQUITEM data indicated its superiority to the conventional TDEM system (PROTEM) during the field test in Marrakech-Tekna Area in terms of depth of investigation. The reconstructed resistivity sections of SQUITEM data by 1-D inversion code also show good agreement with known geology and apparent resistivities of DC resistivity logging.
資源地質学会の論文