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HK: Fachverband Physik der Hadronen und Kerne
HK 20: Astroparticle Physics II
HK 20.2: Vortrag
Dienstag, 12. März 2024, 16:15–16:30, HBR 19: C 103
Low-depolarizing Neutron Supermirrors — •Karina Bernert for the PERC collaboration — Physik-Department, Technische Universität München, Germany
Measurements of free neutron decay enable a variety of tests of the Standard Model of particle physics. Among the observables is the parity-violating beta asymmetry A, i.e. the angular distribution of the beta particles with respect to the neutron spin, with which one can test the unitarity of the quark-mixing Cabibbo-Kobayashi-Maskawa matrix.
The new PERC (Proton Electron Radiation Channel) facility is currently being set up at the research reactor FRM II of the Heinz Maier-Leibnitz Zentrum in Garching, with the aim to measure correlation coefficients one order of magnitude more precisely than previous experiments.
PERC crucially requires low-depolarizing neutron mirrors at the level of 10−4, such that the polarized neutron beam stays sufficiently polarized inside the decay volume. I show preliminary results of a measurement campaign at the ILL PF1b beam line last summer, in which we used the Opaque Test Bench setup to determine the depolarizing effect of different supermirrors. With these measurements we prove that the supermirrors are suitable for the use in PERC and in other experiments that require low depolarization.
Keywords: neutron guide; supermirrors; depolarization; neutron spin