0000000000173255
AUTHOR
J. Karch
First observation of trapped high-field seeking ultracold neutron spin states
Ultracold neutrons were stored in a volume, using a magnetic dipole field shutter. Radial confinement was provided by material walls. Low-field seeking neutrons were axially confined above the magnetic field. High-field seeking neutrons are trapped inside the magnetic field. They can systematically shift the measured neutron lifetime to lower values in experiments with magnetic confinement. ISSN:0370-2693 ISSN:0031-9163 ISSN:1873-2445
Comparison of ultracold neutron sources for fundamental physics measurements
Ultracold neutrons (UCNs) are key for precision studies of fundamental parameters of the neutron and in searches for new CP violating processes or exotic interactions beyond the Standard Model of particle physics. The most prominent example is the search for a permanent electric dipole moment of the neutron (nEDM). We have performed an experimental comparison of the leading UCN sources currently operating. We have used a 'standard' UCN storage bottle with a volume of 32 liters, comparable in size to nEDM experiments, which allows us to compare the UCN density available at a given beam port.
Losses and depolarization of ultracold neutrons on neutron guide and storage materials
At Institut Laue-Langevin (ILL) and Paul Scherrer Institute (PSI), we have measured the losses and depolarization probabilities of ultracold neutrons on various materials: (i) nickel-molybdenum alloys with weight percentages of 82/18, 85/15, 88/12, 91/9, and 94/6 and natural nickel Ni100, (ii) nickel-vanadium NiV93/7, (iii) copper, and (iv) deuterated polystyrene (dPS). For the different samples, storage-time constants up to $\ensuremath{\sim}460\phantom{\rule{0.16em}{0ex}}\mathrm{s}$ were obtained at room temperature. The corresponding loss parameters for ultracold neutrons, $\ensuremath{\eta}$, varied between $1.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and $2.2\ifmmode\t…