Document Type

Conference Paper

Publication Date

2025

DOI

10.22323/1.472.0070

Publication Title

Proceedings of 20th International Workshop on Polarized Source, Targets, and Polarimetry - PoS(PSTP2024)

Volume

472

Pages

070 (12 pp.)

Conference Name

20th International Workshop on Polarized Source, Targets, and Polarimetry (PSTP 2024), 22-27 September 2024, Jefferson Lab, Newport News

Abstract

In this study, AISI 1020 low-carbon steel was investigated as a cost-effective alternative to SS316L stainless steel for reaching extreme high vacuum (XHV) conditions. After being baked at 400°C, a vacuum chamber made of low-carbon steel material exhibited an outgassing rate approximately 2000 times smaller than a similar chamber made of stainless steel. Its activation energy for hydrogen diffusion (27 kJ/mol) is less than half that of stainless steel (60.3 kJ/mol), indicating more efficient hydrogen removal during bakeout. MolFlow+ simulations supported the experimental data and demonstrated the importance of system geometry optimization and minimizing stainless steel content for achieving optimal vacuum performance. AISI 1020's magnetic properties, typically considered disadvantageous for accelerator applications, could benefit spin-polarized electron sources by shielding photocathodes from stray fields while simultaneously providing improved vacuum through reduced outgassing. To optimize AISI 1020's performance in XHV systems, practical considerations include pre-baking protocols and careful system design to minimize stainless steel components.

Rights

2025 © Copyright owned by the authors under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) License.

Original Publication Citation

Al-Allaq, A. H., Mamun, M. A., Poelker, M., & Elmustafa, A. (2025). Optimizing material selection and operational conditions for XHV systems: Lessons from AISI 1020 and 316I comparative studies. Proceedings of 20th International Workshop on Polarized Source, Targets, and Polarimetry - PoS(PSTP2024). 472, 070. https://doi.org/10.22323/1.472.0070

ORCID

0000-0002-0415-2795 (Al-Allaq)

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