SERIAL ARRAY HIGH-TC SQUID MAGNETOMETER

SQUID magnetometers have been fabricated from series arrays of YBa2Cu3 O7 dc SQUIDs by pulsed laser film deposition and ion mill patterning t echniques. The array was designed either in linear chain with flux foc users or in meander structure. The arrays consisted of 50-130 step-edg e junction SQUIDs and each SQUID had inductance of 20-40 pH with 2-5 m u m junction width. A linear array of 50 SQUIDs showed a modulation am plitude of 150 mu V which corresponds to a gain of similar to 10. One of 80 SQUID meander arrays had a gain of as high as 50. These results provide feasibility of the series array of SQUIDs in the direct readou t SQUID amplifier circuitry with wide bandwidth. Larger number SQUID a rrays and processes to increase the gain to the theoretical value need to be studied.