Measurement of spin-flip probabilities for ultracold neutrons interacting with nickel phosphorus coated surfaces

Abstract

We report a measurement of the spin-flip probabilities for ultracold neutrons interacting with surfaces coated with nickel phosphorus. For 50~$\mu$m thick nickel phosphorus coated on stainless steel, the spin-flip probability per bounce was found to be ${\beta }_{\mathrm{NiP}\mathrm{on}\mathrm{SS}}=(3.3_{-5.6}^{+1.8})\times 10^{-6}$. For 50~$\mu$m thick nickel phosphorus coated on aluminum, the spin-flip probability per bounce was found to be ${\beta }_{\mathrm{NiP}\mathrm{on}\mathrm{Al}}=(3.6_{-5.9}^{+2.1})\times 10^{-6}$. For the copper guide used as reference, the spin flip probability per bounce was found to be ${\beta }_{\mathrm{Cu}}=(6.7_{-2.5}^{+5.0})\times 10^{-6}$. The results on the nickel phosphorus-coated surfaces may be interpreted as upper limits, yielding ${\beta }_{\mathrm{NiP}\mathrm{on}\mathrm{SS}}<6.2\times 10^{-6}$ (90\% C.L.) and ${\beta }_{\mathrm{NiP}\mathrm{on}\mathrm{Al}}<7.0\times 10^{-6}$ (90\% C.L.) for 50~$\mu$m thick nickel phosphorus coated on stainless steel and 50~$\mu$m thick nickel phosphorus coated on aluminum, respectively. Nickel phosphorus coated stainless steel or aluminum provides a solution when low-cost, mechanically robust, and non-depolarizing UCN guides with a high-Fermi-potential are needed.

arXiv comment12 pages, 5 figures

References in corpus (8)

• A Unified Approach to the Classical Statistical Analysis of Small Signals
• An Improved Experimental Limit on the Electric Dipole Moment of the Neutron
• The neutron and its role in cosmology and particle physics
• Precision Measurement of the Neutron Beta-Decay Asymmetry
• Measurement of the neutron $\beta$-asymmetry parameter $A_0$ with ultracold neutrons
• Storage of ultracold neutrons in the UCN$\tau$ magneto-gravitational trap
• A multilayer surface detector for ultracold neutrons
• Neutron production and thermal moderation at the PSI UCN source

Cited by in corpus (7)

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• Characterization of electroless nickel-phosphorus plating for ultracold-neutron storage
• A non-depolarizing CuTi neutron supermirror guide for PERC
• Estimated performance of the TRIUMF ultracold neutron source and electric dipole moment apparatus
• Characterization of the new Ultracold Neutron beamline at the LANL UCN facility
• Fill and dump measurement of the neutron lifetime using an asymmetric magneto-gravitational trap