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Related papers: Consistent description of UCN transport properties

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The reflectivity of ultracold neutron (UCN) guides produced with a dedicated technique called {\sc Replika} has been studied. The guides are made of nickel, where the surface quality was copied from a glass layer. This results in a surface…

Instrumentation and Detectors · Physics 2007-05-23 Christian Plonka , Peter Geltenbort , Torsten Soldner , Harald Haese

Metal tubes plated with nickel-phosphorus are used in many fundamental physics experiments using ultracold neutrons (UCN) because of their ease of fabrication. These tubes are usually polished to a average roughness of 25-150 nm. However,…

There are worldwide efforts to search for physics beyond the Standard Model of particle physics. Precision experiments using ultracold neutrons (UCN) require very high intensities of UCN. Efficient transport of UCN from the production…

Instrumentation and Detectors · Physics 2015-12-09 B. Blau , M. Daum , M. Fertl , P. Geltenbort , L. Goeltl , R. Henneck , K. Kirch , A. Knecht , B. Lauss , P. Schmidt-Wellenburg , G. Zsigmond

Efficient neutron transport is a key ingredient to the performance of ultracold neutron (UCN) sources, important to meeting the challenges placed by high precision fundamental physics experiments. At the Paul Scherrer Institute's UCN source…

Instrumentation and Detectors · Physics 2022-06-22 G. Bison , M. Daum , K. Kirch , B. Lauss , D. Ries , P. Schmidt-Wellenburg , G. Zsigmond

Modeling the motion of ultracold neutrons (UCNs) is crucial for assessing their losses, accurately measuring their lifetime, and describing other experiments. In material traps, it is necessary to account not only for specular but also for…

Instrumentation and Detectors · Physics 2025-03-04 P. D. Grigoriev , V. D. Kochev , V. A. Tsyplukhin , A. M. Dyugaev , I. Ya. Polishchuk

The improvement of the number of extractable ultracold neutrons (UCNs) from converters based on solid deuterium (sD$_2$) crystals requires a good understanding of UCN transport and how the crystal's morphology influences its transparency to…

Instrumentation and Detectors · Physics 2021-01-13 Stefan Döge , Jürgen Hingerl

The extraction efficiency of ultracold neutrons from cryogenic moderators depends critically on the neutron transparency of the moderator material. The Monte Carlo simulation of the probability of the UCN going out from non-ideal…

Nuclear Experiment · Physics 2015-06-03 Yu. N. Pokotilovski

UHE cosmic neutrino interaction with the cosmic neutrino background (CnuB) is expected to produce absorption dips in the UHE neutrino flux at energies above the threshold for Z-boson resonant production. The observation of these dips would…

Astrophysics · Physics 2008-11-26 V. Van Elewyck

Ultra-cold neutrons (UCN), neutrons with energies low enough to be confined by the Fermi potential in material bottles, are playing an increasing role in measurements of fundamental properties of the neutron. The ability to manipulate UCN…

We report experiments on the production of ultracold neutrons (UCN) in a converter of superfluid helium coated with fluorinated grease. We employed our technique of window-free extraction of accumulated UCN from the helium, in which they…

Nuclear Experiment · Physics 2008-02-01 O. Zimmer , P. Schmidt-Wellenburg , M. Assmann , M. Fertl , J. Klenke , S. Mironov , H. -F. Wirth , B. van den Brandt

We investigate the possibility of ultracold neutron (UCN) storage in quantum states defined by the combined potentials of the Earth's gravity and the neutron optical repulsion by a horizontal surface of liquid helium. We analyse the…

Nuclear Experiment · Physics 2016-08-31 P. D. Grigoriev , O. Zimmer , T. Ziman , A. D. Grigoriev

We present a first experimental demonstration of a new method to extract a well-collimated beam of ultra-cold neutrons (UCN) from a storage vessel. Neutrons with too large divergence are not removed from the beam by an absorbing…

Instrumentation and Detectors · Physics 2009-11-13 P. Schmidt-Wellenburg , J. Barnard , P. Geltenbort , V. V. Nesvizhevsky , C. Plonka , T. Soldner , O. Zimmer

We analyze accumulation of ultracold neutrons (UCN) in a superfluid-helium converter vessel surrounded by a magnetic multipole reflector. We solved the spin-dependent rate equation, employing formulas valid for adiabatic spin transport of…

Instrumentation and Detectors · Physics 2015-03-05 O. Zimmer , R. Golub

We propose a method to increase both the neutron storage time and the precision of its lifetime measurements by at least tenfold. The storage of ultracold neutrons (UCN) in material traps now provides the most accurate measurements of…

Instrumentation and Detectors · Physics 2021-11-22 P. D. Grigoriev , A. M. Dyugaev

Searches for the permanent electric dipole moment of the neutron (nEDM) provide strong constraints on theories beyond the Standard Model of particle physics. The TUCAN collaboration is constructing a source for ultracold neutrons (UCN) and…

Instrumentation and Detectors · Physics 2023-05-03 Steve Sidhu , Wolfgang Schreyer , Sean Vanbergen , Shinsuke Kawasaki , Ryohei Matsumiya , Takahiro Okamura , Ruediger Picker

We have investigated experimentally the pressure dependence of the production of ultracold neutrons (UCN) in superfluid helium in the range from saturated vapor pressure to 20bar. A neutron velocity selector allowed the separation of…

Nuclear Experiment · Physics 2015-09-02 P. Schmidt-Wellenburg , J. Bossy , E. Farhi , M. Fertl , K. K. H. Leung , A. Rahli , T. Soldner , O. Zimmer

The work presented in this thesis forms part of a program at the Paul Scherrer Institute (PSI) to construct a high intensity superthermal ultra-cold neutron (UCN) source based on solid deuterium as UCN production medium. We carried out a…

Nuclear Experiment · Physics 2007-05-23 Malgorzata Kasprzak

It is generally accepted that the main cause of ultracold neutron (UCN) losses in storage traps is the upscattering to the thermal energy range by hydrogen adsorbed on the surface of the trap walls. However, the data on which this…

The TUCAN (TRIUMF UltraCold Advanced Neutron) Collaboration is completing a new ultracold neutron (UCN) source. The UCN source will deliver UCNs to a neutron electric dipole moment (EDM) experiment. The EDM experiment is projected to be…

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