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TY - CONF AU - Michaud, J. AU - De Conto, J.-M. AU - Gómez Martínez, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Effect of Electrostatic Deflectors and Fringe Fields on Spin for Hadron Electric Dipole Moment Measurements on Storage Rings J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The observed matter-antimatter asymmetry in the universe cannot be explained by the Standard Model. An explanation is a non-vanishing Electric Dipole Moment of subatomic particles. The JEDI (Jülich Electric Dipole moment Investigations) collaboration is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. To achieve this, one needs a stable polarization, i.e. around 1000 seconds for spin coherence time. One source of decoherence are the electrostatic deflectors, and this must be quantified. We developed an analytical model for cylindrical deflectors, including fringe fields, and the associated beam and spin transfer functions, integrated over the deflector. All boundaries (including ground) are considered, giving a realistic, accurate field map up to any order. We get universal formulas, the only adjustable parameter being the deflector gap/radius ratio, all other terms being numerical. This has been implemented in BMAD. We present the mathematical, physical and numerical developments, as well as results for a proton storage ring. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1691 EP - 1693 KW - storage-ring KW - dipole KW - polarization KW - controls KW - vacuum DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB006 UR - http://jacow.org/ipac2019/papers/tuprb006.pdf ER -