Conveners
Cryogenics
- Kazuhiro Yamamoto
Description
Cryogenics for future detectors
We will reassert the scientific reasons for using cryogenics to increase the sensitivity of low-frequency ET, we will focus on studies related to the structure of cryogenic payload and superfluid helium cryostat, in addition to studies on cryo-pumps to be used in ET. We will conclude by presenting a brief review of cryogenic facilities under development at the various laboratories of...
The Einstein Telescope (ET) is hosting interferometers to detect both low-frequency (LF) and high-frequency gravitational wave signals.
In order to reduce thermal noise, the main optics will partly be cooled to cryogenic temperatures below 20 K for ET-LF. Here, special measures are needed to mitigate frost formation on the cryogenic mirror, which is critical due to degradations of the optical...
The advent of future cryogenic wave detectors pose stringent criteria on noise from residual gas. Depending on the mirror temperature, different gas species may sublimate. Furthermore, the residual gas may cause optical path length changes in the arms and cause Brownian motion. The outgassing from gas from different surfaces (cables, thermal shields, vacuum vessels depends on the temperature...
The proposed LIGO Voyager upgrade would require novel 2-μm interferometric techniques and radiative cooling of 200 kg silicon optics to cryogenic temperatures. Efficient cooldown to 123K is contingent upon strong radiative heat transfer between test masses and cold shielding. The strength of radiative coupling is largely dependent on surface emissivities, which must be high enough to offset...
Einstein Telescope nominal sensitivity, below 20 Hz, implies innovative technologies associated to cryogenics and revised mechanical design for test mass suspension. It is foreseen to cool the main optics and their suspensions down to 10-20 K. The use of solid thermal conduction and pulse-tube technology appears suitable if properly designed. The reduction of technical noise is demanding and...
To reduce the impact of thermal noises in the sensitivity of gravitational wave detectors, cryogenic operation is planned for future 3G detectors such as Einstein Telescope and it is already implemented in the 2.5G detector KAGRA. To benefit from cryogenic operations, test masses substrate material needs to be changed from amorphous fused silica to crystalline material. The choice of KAGRA for...
