Coupling of a high-sensitivity superconducting amplifier to a gravitational-wave antenna

Journal Article · Sun Dec 01 04:00:00 EST 1985 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.32.3258· OSTI ID:5009871

Carelli, P; Castellano, M G; Cosmelli, C; Foglietti, V; Modena, I

We report the first measurements on a dc superconducting quantum interference device (dc-SQUID) coupled to a gravitational wave detector cooled down to liquid-helium temperature. The overall system is composed of a 2.3-ton aluminum bar and a resonant capacitive transducer coupled to the dc-SQUID amplifier by means of a high-ratio superconducting transformer. The SQUID used in this experiment is a planar device with a multiple-loop geometry having both low noise and good coupling with the external world. The electromechanical equivalent circuit of the system, which is essentially a set of three coupled oscillators, is analyzed in detail in its normal modes and an expression for the effective noise temperature for each mode is given. Measurements are reported on the SQUID alone, on the SQUID plus the high-ratio transformer, and on the SQUID coupled to the antenna in parallel with a field-effect transistor preamplifier.

• Research Organization: Istituto di Elettronica dello Stato Solido, Consiglio Nazionale delle Ricerche via Cineto Romano 42, 00156 Roma, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Roma, 00185 Roma, Italy
• OSTI ID: 5009871
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 32:6; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640106* -- Astrophysics & Cosmology-- Cosmology
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFIERS
ANTENNAS
COUPLING
DETECTION
ELECTRICAL EQUIPMENT
ELECTROMECHANICS
ELECTRONIC EQUIPMENT
EQUIPMENT
FLUXMETERS
GRAVITATIONAL WAVES
MEASURING INSTRUMENTS
MECHANICS
MICROWAVE EQUIPMENT
NOISE
SENSITIVITY ANALYSIS
SQUID DEVICES
SUPERCONDUCTING DEVICES
ULTRALOW TEMPERATURE