Speaker
Description
Building upon the success of the LIGO and Virgo experiments in gravitational wave (GW) detection, the GW community is now setting its sights on new laser interferometers capable of detecting GWs from cosmological events spanning a much larger volume of the universe and occurring in its early phases. In pursuit of this objective, the European community has proposed the construction of the Einstein Telescope (ET), a complex comprising six interferometers arranged within a triangular tunnel spanning 10 km on each side. To mitigate noise stemming from statistical pressure fluctuations, the laser beams necessitate Ultra-High Vacuum (UHV) conditions within a 1 meter diameter beamtube, extending across a total vacuum length of 120 km. However, the projected cost of the ET vacuum system, based on previous-generation GW detectors, is notably high, second only to that of the civil engineering. To address this challenge, CERN, in collaboration with other institutes, has launched a study to explore alternative and more cost-effective technological solutions. This investigation includes assessing the UHV compatibility of various steels, potentially eliminating high-temperature degassing treatments, optimising bakeout temperatures, designing and implementing thin-walled pipes, and optimising vacuum layouts and tunnel integration logistics. To validate these optimisations, a 36-meter-long pilot sector is under construction at CERN.