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Sep 22 – 27, 2024
Jefferson Lab
US/Eastern timezone

Amorphous Carbon-coated Storage Cell Tests for the Polarized Gas Target at LHCb

Sep 26, 2024, 11:20 AM
20m
Cebaf Center Auditorium (Jefferson Lab)

Cebaf Center Auditorium

Jefferson Lab

12000 Jefferson Ave. Newport News, VA 23606

Speaker

Ralf Engels

Description

The LHC beams cannot be polarized. Hence, the implementation of a dense polarized gas target at the LHCb experiment at CERN, to be operated simultaneously with beam-beam collisions, will enable fixed target interactions to explore a new energy range of spin physics measurements. Unfortunately, typical surface coatings like water, Teflon or aluminium, normally used to avoid polarization losses, are forbidden due to vacuum and beam policies.
Using the former ANKE atomic beam source at Forschungszentrum Jülich to provide a polarized atomic hydrogen beam, we investigated the properties of a storage cell coated with amorphous carbon. A notable recombination rate, lying between 93 and 100 %, and a preservation of polarization during recombination exceeding 74 % was observed. We were able to generate H$_2$ molecules with a nuclear polarization of P ~ −0.59. Remarkably, no water layer accumulated on the cooled storage cell surface, even over extended periods. Furthermore, we examined the influence of Lyman-α radiation on the recombination rate on carbon, addressing a prominent question in the field of astrophysics.

Primary author

Ralf Engels

Co-authors

Dr Chrysovalantis Kannis (Institut für Kernphysik (IKP), Forschungszentrum Jülich) Kiril Grigoryev (GSI Darmstadt) Massimiliano Ferro-Luzzi (CERN) Pasquale Di Nezza (INFN Frascati) Mr Pedro Costa Pinto (CERN) Simon Pütz (FZ Jülich) Tarek El-Kordy (FZ Jülich)

Presentation materials