相关论文: Temperature Dependence of the UCN Loss Rate

In work [1] ("Temperature dependence of ultracold neutron loss rates" E.Korobkina et al., PRB 70,035409) results of measurement of temperature dependence of losses of ultracold neutrons (UCN) in a range from 4 K to 300 K at UCN storage in a…

We present experimental measurements of the properties of a liquid "Fomblin" surface obtained by the quasielastic scattering of laser light. The properties include the surface tension and viscosity as a function of temperature. The results…

Ultracold neutrons (UCNs) were produced in a 4 liter volume of superfluid helium using the PF1B cold neutron beam facility at the Institut Laue-Langevin and then extracted to a detector at room temperature. With a converter temperature of…

The ultracold neutron (UCN) upscattering rate from para-deuterium contaminated solid deuterium near T=0K is calculated and found to be 4 msec for a room-temperature-equilibrium concentration. The para-deuterium contamination appears to be…

The transparency of metal foils for ultracold neutrons (UCNs) plays an important role in the design of future high-density UCN sources, which will feed a number of fundamental physics experiments. In this work, we describe and discuss the…

Ultracold neutrons provide a unique tool for the study of neutron properties. An overview is given of the ultracold neutron (UCN) source at PSI, which produces the highest UCN intensities to fundamental physics experiments by exploiting the…

We present experimental data on ultracold neutron (UCN) production in solid oxygen from 5 K to 50 K. The experiment used 3 cells of different dimensions in order to study the excess UCN elastic scattering in s-O$_2$ due to source density…

SuperSUN, a new superthermal source of ultracold neutrons (UCN) at the Institut Laue-Langevin, exploits inelastic scattering of neutrons in isotopically pure superfluid $^4$He at temperatures below $0.6\,$K. For the first time, continuous…

We determined the ultracold neutron (UCN) production rate by superthermal conversion in the solid deuterium (sD$_2$) moderator of the UCN source at the Paul Scherrer Institute (PSI). In particular, we considered low amounts of less than…

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…

Two hypothesizes concerning interaction of neutrons with nanoparticles and having applications in the physics of ultracold neutron (UCN) were recently considered in ref. [Physics of Atomic Nuclei 65(3): 400 (2002)]; they were motivated by…

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…

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…

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…

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…

While the optical properties of thin metal films are well understood in the visible and near-infrared range, little has been done in the mid- and far-infrared region. Here we investigate ultra-thin gold films prepared on Si(111)(7 x 7) in…

Ultracold neutrons (UCN), stored in a cell with hard walls that is attached to, and therefore rotating with, the Earth, will experience non-inertial frame effects, resulting in a broadening of the UCN spectrum. A heating or cooling of the…

We present the results of an Ultracold neutron (UCN) production experiment in a pulsed neutron beam line at the Los Alamos Neutron Scattering Center. The experimental apparatus allows for a comprehensive set of measurements of UCN…

A new intense superthermal source for ultracold neutrons (UCN) has been installed at a dedicated beam line at the Institut Laue-Langevin. Incident neutrons with a wavelength of 0.89 nm are converted to UCN in a five liter volume filled with…

To investigate a mysterious superconducting state of URu_2Si_2 embedded in the so-called hidden order state, the lower critical field H_{c1} is precisely determined down to 55 mK for H || a and H || c. For this purpose, the positional…