186,881 research outputs found
Measurements at T=4.2 K of Mechanical Transfer Function and Brownian Noise of a Small (M=20.3 kg) Gravitational Wave Antenna on High Attenuation Suspension
No full textPush pull resonant capacitive transducer for parametric measurements schemes on cryogenic gravitational wave antennas
No full textP. F. Michelson editor, Word Scientific
Anelastic; elastic properties of a synthetic monocrystal of bismuth germanate Bi4Ge3O12 at low temperatures
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Conceptual cryostat design for cryogenic payload suspension studies for the Einstein Telescope
No full textThe Einstein Telescope (ET) is a third generation gravitational wave detector, combining a low-frequency (LF) and a high-frequency (HF) laser interferometer. Cryogenic operation of ET-LF in the temperature range of 10K to 20K is essential to suppress the suspension thermal noise, which dominates the detection sensitivity at frequencies below 10 Hz. This requires suspension materials with high thermal conductivity and low mechanical dissipation at cryogenic temperatures. Two possible suspension concepts are currently considered, using either monocrystalline suspension fibers made of silicon or sapphire, or titanium suspension tubes filled with static He-II. The dissipative behavior of these suspensions is characterized by the mechanical Q-factor. It can be measured by the ring-down method, exciting the suspensions to resonance vibrations on the nanometer scale and analyzing the decay time. For this purpose, a newcryogenic test facility is being planned, allowing the investigation of cryogenic payload suspensions for third-generation gravitational wave detectors. The test cryostat is equipped with a cryocooler and enables real-size studies with various suspension materials and geometries. The future integration of He-II is foreseen to enable He-II filled suspension studies. We describe the scope of experiments and the conceptual design of the test cryostat
Vibration Free Cryostat for cooling suspended mirrors
No full textA new generation of gravitational wave interferometers is under study with the main goal to improve the sensitivity of the present detectors which are taking data now. Two of the dominant noises which limit the actual sensitivity of the interferometers are the thermal noise of the suspended optics and the thermal lensing process. At low temperature it is possible to reduce both the effects. However, lowering the temperature of the test masses without injecting vibration noise from the cooling system is a technological challenge. We present the first results on a new active system to dampen the vibrations from a pulse tube refrigerator coupled to a suspended mirror
Experimental study of a Back Action Evading device for continuos measurements on a macroscopic harmonic oscillator at the quantum limit level
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