¶ Thermal Compensation System
The Thermal Control System (TCS) is required to:
- adjust the arm cavity spot size by adding up to 30 μDioptre of power to all test mass HR surfaces
- compensate thermal aberrations in the recycling cavities sufficiently to maintain adequate RF sideband power buildup
- maintain recycling cavity and arm cavity mode overlap to within 95%, and
- maintain the contrast defect ratio by limiting the additional dc power at the OMC to within 1 mW. The TCS capability to alter the test mass radius-of-curvature can also be used to adjust the transverse optical mode spacing and potentially control optical-acoustic parametric instabilities at high optical power.
The TCS consists of three major elements a radiative ring heater (RH), a CO2 laser projector (CO2P) and a Hartmann wavefront sensor (HWS). The RH is used to correct surface deformation of the ITM and ETM, and to partially correct the ITM substrate thermal lens. The CO2P is used to compensate residual ITM substrate distortions not corrected by the RH. The HWS is used to measure the test mass thermal aberrations.
¶ Schematic Layout
The LIGO Scientific Collaboration
¶ Channel Name Breakdown:
| Name | Description |
|---|---|
| Channels | |
| TCS | Thermal Compensation System |