Speakers
Description
The optical aberration budget in present-day gravitational wave detectors is a key driver for the commissioning effort to stabilize the interferometer working point. In Advanced Virgo, extensive experience in thermal compensation of cold optical defects and high-power absorption-induced lensing has been developed within the Thermal Compensation System (TCS), in close interplay with other subsystems, particularly ISC (ITF Sensing and Control).
In view of a new design of the layout of Advanced Virgo with stable recycling cavities - to be implemented in phases toward O5, TCS has developed a technical design plan involving upgrades of its main components, including both new concepts and experience-guided system evolutions. All these strategies are included in the O5 technical design review document, considering the interfaces with other subsystems, the integration plan and the mitigation of correlated risks. The compensation of optical aberrations is also a crucial development in view of future detectors, addressing increased circulating power, tighter stability requirements, and growing system complexity.
We present the design choices for the TCS system upgrades in view of O5 Advanced Virgo layout with stable recycling cavities, discussing the drivers, the impacts and the upgrade strategy. The deployment follows a staged implementation aligned with the O5 upgrade plan. Besides, starting from the O5 TCS design, we outline the developments of the thermal compensation in view of future detectors, particularly post-O5 upgrades and Einstein Telescope, focusing on the most relevant R&D.