Design Consideration on a Polarized Gas Target for the LHC

TL;DR

This paper discusses the design considerations for implementing a polarized gas target at the LHC to enable spin asymmetry measurements, focusing on technical challenges and experimental plans.

Contribution

It presents the design considerations and technical challenges for installing a polarized gas target in the LHC, including a planned warm test storage cell.

Findings

Design considerations for a polarized gas target at LHC

Development of a warm test storage cell for LHCb

Strategies to prevent beam instabilities

Abstract

Since 2017, the LHCSpin study group is investigating the installation of a HERMES-type polarized gas target (PGT) in front of the LHCb detector in order to perform Single-Spin Transverse Asymmetry (SSTA) measurements. In cooperation with LHC experts, the conditions for applying a PGT are being studied. As a viable option, a cold openable storage cell is considered. A key role for avoiding instabilities of the 7 TeV proton beam is the choice of a proper coating and the suppression of wake fields. A first warm (300 K) test storage cell is planned for installation in 2019 inside the VELO vessel, subject to final approval. It will improve the ongoing SMOG program of LHCb fixed target measurements, and will provide valuable experience of running a storage cell in the harsh LHC environment. The status of the design considerations on a PGT in the LHC beam and of the discussion of critical machine issues is presented.