J. Phys. IV France 08 (1998) Pr3-229-Pr3-232
Towards practical quantum-limited SQUlDs for a gravitational wave antennaJ. Flokstra, E. Bartolomé, M.J. Van Duuren, G.C.S. Brons, D. Veldhuis and H. Rogalla
Low Temperature Division, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
Nearly quantum-limited Superconducting QUantum Interference Devices (SQUIDs) have to be used in resonant mass gravitational wave antennas to reach a displacement sensitivity of the order of 10-21 nV/√Hz in a bandwidth of 100 Hz around the resonance frequency of about 900 Hz. The design of these dc SQUIDs will be described. The possible use of Double Relaxation Oscillation SQUIDs (DROSs) was also studied. We show that SQUIDs with a relatively large hole size can reach the quantum limit at low temperatures. The large hole size facilitates the coupling between the SQUID and the inductive transformer circuit of the antenna.
© EDP Sciences 1998