Ultralow magnetic fields and Gravity Probe B gyroscope readout
| Autor: | Barry Muhlfelder, D.O. Murray, John Mester, M. Taber, J. M. Lockhart |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Superconductivity
Physics Atmospheric Science Field (physics) Physics::Instrumentation and Detectors Rotor (electric) business.industry Attenuation Aerospace Engineering Astronomy and Astrophysics Gyroscope London moment law.invention Magnetic field Geophysics Optics Nuclear magnetic resonance Space and Planetary Science law General Earth and Planetary Sciences Spin (physics) business |
| Zdroj: | Advances in Space Research. 25:1185-1188 |
| ISSN: | 0273-1177 |
| Popis: | We describe the generation of an ultralow magnetic field of −11 Tesla in the flight dewar of the Gravity Probe B Relativity Mission. The field was achieved using expanded-superconducting-shield techniques and is maintained with the aid of a magnetic materials control program. A high performance magnetic shield system is required for the proper function of gyroscope readout. The readout system employs a dc SQUID to measure the London moment generated by the superconducting gyro rotor in order to resolve sub-milliarcsecond changes in the gyro spin direction. In addition to a low residual dc magnetic field, attenuation of external field variation is required to be 10 12 at the gyro positions. We discuss the measurement of the dc magnetic field and ac attenuation factor and the performance of the readout system. |
| Databáze: | OpenAIRE |
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