Reaching ultra-high vacuum for a large vacuum vessel in an underground environment

• Published in: E3S web of conferences Vol. 357; p. 5001
• Main Authors: Sabulsky, D. O., Zou, X., Junca, J., Bertoldi, A., Prevedelli, M., Beaufils, Q, Geiger, R, Landragin, A., Boyer, D., Gaffet, S., Bouyer, P, Canuel, B.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Les Ulis EDP Sciences 01.01.2022
• Subjects: Background noise; Contamination; Geophysics; Gravitational waves; Heating; High vacuum; Infrastructure; Physics; Quantum Physics; Residual gas; Temporal variations; Vacuum; Vessels
• ISSN: 2267-1242; 2555-0403; 2267-1242
• DOI: 10.1051/e3sconf/202235705001

Located far from anthropical disturbances and with low seismic and magnetic background noise profiles, the LSBB facility is the ideal location for a new hybrid detector for the study of space-time strain. The MIGA infrastructure [1], utilizes an array of atom interferometers manipulated by the same beam, the resonant optical field of a 150 m long optical cavity. The infrastructure constitutes a new method for geophysics, for the characterization of spatial and temporal variations of the local gravity, and is a demonstrator for future decihertz gravitational wave observation. Such an infrastructure requires ultra-high vacuum (10 −9 mbar) on a size (150 m) and scale (36 m 3 ) not typically seen in underground laboratories other than CERN [2], and especially in underground environments with high humidity (up to 100%) and significant dust contamination (milimetric to micrometric porous rock particles). Here, we detail the status of the MIGA infrastructure and describe the ongoing generation and analysis of the vacuum works - this comes from tests of the prototype vacuum vessel, focusing on heating cycles, residual gas and heating analysis.