The EDM polarimeter development at COSY-Jülich
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The JEDI (Jülich Electric Dipole moment Investigations) collaboration performs a set of experiments at the COSY storage ring in Jülich, to search for the Electric Dipole Moments (EDMs) of charged particles (JEDI Collaboration ). A measurement of proton and deuteron EDMs is a sensitive probe of yet unknown CP violation. The method of charged particle EDM search will exploit stored polarized beams in order to observe a miniscule rotation of the polarization axis as a function of time due to the interaction of a finite EDM with large electric fields. Key challenge is the provision of a sensitive and efficient method to determine the tiny change of the beam polarization. Elastic scattering of the beam particles on carbon nuclei will provide the polarimetry reaction. To perform these measurements, an EDM polarimeter needs to be developed. The polarimetry concept realized within the JEDI collaboration is based on a heavy crystal (LYSO) hadron calorimeter. LYSO as a fast, dense and radiation hard, novel scintillating material was chosen to fulfill these specifications. The polarimeter is designed in a compact and modular fashion consisting of modules made from LYSO crystals coupled to silicon photomultipliers (SiPM).
KeywordsPolarimetry LYSO SiPM EDM
The author wishes to thank all involved members of the JEDI Collaboration and of the Institut für Kernphysik of Forschungszentrum Jülich. This work has been financially supported by Forschungszentrum Jülich GmbH and by an ERC Advanced-Grant (srEDM #694340) of the European Union.
- 1.JEDI Collaboration, proposals avalable at http://collaborations.fz-juelich.de/ikp/jedi/ (2011)
- 2.PreLude 420 LYSO scintillator crystals by Saint-Gobain Crystals, https://www.crystals.saint-gobain.com/sites/imdf.crystals.com/files/documents/lyso-material-data-sheet_1.pdf
- 3.SenseL ARRAYJ-30020-64P-PCB SiPM, 64 × 3mm × 3mm array, 20 μ m cells, https://www.onsemi.com/pub/Collateral/ARRAYJ-SERIES-D.PDF