Magnetic Shielding Simulation for the PMTs at the Two-Arm Spectrometer for the SRC Project at BM@N

Le résumé fourni par la source

Abstract BM@N is the first operating fix-target experiment at the future NICA collider facility at JINR (Dubna, Russia). BM@N is using ion beams from the Nuclotron accelerator ring to study the properties of cold dense baryonic matter. In 2017 the physics program of BM@N was extended by studies of Short-Range Correlations (SRC) in carbon nuclei. The first SRC measurement took place in 2018, and the first results were published in 2021 [1]. The second measurement of SRC in inverse kinematics planned for fall 2021 aims at measuring absolute cross-sections, improving resolutions, and increasing the statistics by at least an order of magnitude. A new calorimeter for proton-pion separation consisting of the large area neutron detector (LAND) [2] modules will be used for the two-arm spectrometer. The location of the new calorimeter right next to the SP-41 analyzing magnet requires protection of the photomultiplier tubes (PMT) at the ends of the calorimeter modules from the external magnetic field. A detailed magnetic field simulation within Ansoft Maxwell 15.0 allowed to estimate the magnetic field magnitude in the area of PMTs and confirm that a passive magnetic shielding is enough to avoid gain loss in the PMTs.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.