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

D O Sabulsky (1) , X. Zou (1) , J. Junca (1) , A. Bertoldi (1) , M. Prevedelli (2) , Q Beaufils (3) , R Geiger (3) , A. Landragin (3) , D. Boyer (4) , S. Gaffet (4) , P Bouyer (1) , B. Canuel

1 LP2N - Laboratoire Photonique, Numérique et Nanosciences
2 UNIBO - Alma Mater Studiorum Università di Bologna = University of Bologna
3 LNE - SYRTE - Laboratoire national de métrologie et d'essais - Systèmes de Référence Temps-Espace
4 LSBB - Laboratoire Souterrain à Bas Bruit

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.

Domaines: Physique Quantique [quant-ph]

D O Sabulsky, X. Zou, J. Junca, A. Bertoldi, M. Prevedelli, et al.. Reaching ultra-high vacuum for a large vacuum vessel in an underground environment. E3S Web of Conferences, 2022, 357, pp.05001. ⟨10.1051/e3sconf/202235705001⟩. ⟨hal-03819841⟩