CERN Accelerating science

Article
Report number	arXiv:2406.07123
Title	Study of selected mild steels for application in vacuum systems of future gravitational wave detectors
Author(s)	Scarcia, Carlo (CERN ; RWTH Aachen U.) ; Bregliozzi, Giuseppe (CERN) ; Chiggiato, Paolo (CERN) ; Michet, Alice Ingrid (CERN) ; Perez Fontenla, Ana Teresa (CERN) ; Rimoldi, Martino (CERN) ; Taborelli, Mauro (CERN) ; Wevers, Ivo (CERN)
Publication	2024-09-01
Imprint	2024-06-11
Number of pages	17
In:	J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. 42, 5 (2024) pp.054202
DOI	10.1116/6.0003820 (publication) 10.1116/6.0003820 (publication)
Subject category	astro-ph.IM ; Astrophysics and Astronomy ; physics.acc-ph ; Accelerators and Storage Rings
Abstract	Next-generation gravitational wave detectors (GWDs) like the Cosmic Explorer and Einstein Telescope require extensive vacuum tubing, necessitating cost-effective materials. This study explores the viability of mild steel as an alternative to austenitic stainless steel for UHV beampipes, focusing on outgassing rates and surface chemistry after low-temperature bakeouts. Mild steels exhibit significantly lower hydrogen outgassing rates, below 10$^{-14}$ mbar l s$^{-1}$ cm$^{-2}$ after bakeouts at 80{\deg}C for 48 hours. While water vapor is the primary residual gas after such low-temperature bakeouts, repeated treatments reduce its outgassing rate and modify surface conditions so that such benefit is preserved after at least six months of exposure to laboratory air. These findings position mild steel as an economical and efficient material for future GWD beampipes.
Copyright/License	preprint: (License: CC BY-NC-ND 4.0) publication: © 2024 Author(s) (License: CC-BY-4.0)

Corresponding record in: Inspire