Three-Dimensional Analysis of the Polarization of Scattered Neutrons of the Thermal,Cold, and Very Cold Spectrum in Studies of the Magnetic Dynamics of Endometallofullerenes

Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques - A method for studying the magnetic dynamics of endofullerenes M@C2n (2n = 60, 70, …) and their derivatives,...     

Analysis of the Results of the Neutrino-4 Experiment on the Search for the Sterile Neutrino and Comparison with Results of Other Experiments

JETP Letters - New measurements of the flux and spectrum of reactor antineutrinos as functions of the distance from the center of the core of the SM-3 reactor (Dimitrovgrad, Russia) in the range of...     

Simulation of Experiment on Measurement of Neutron Lifetime Using the Big Gravitational Trap of Ultracold Neutrons with the Absorber

Technical Physics - At present, the experiment on measuring neutron lifetime using a big gravitational trap is being performed at Petersburg Nuclear Physics Institute. It is planned to achieve a...     

Gradiometric investigation of a cesium-vapor quantum magnetometer

Experiments aimed to determine the sensitivity and the optical shift of the output frequency of a magnetometer based on optical pumping of cesium atoms and intended for a neutron magnetic resonance stabilization system are described. A gradiometric arrangement used in these experiments makes it possible to reduce the effect of magnetic field variations on measurements.     

Supersource of ultracold neutrons at the WWR-M reactor and the program of fundamental research in physics

A high-intensity source of ultracold neutrons (UCNs) and very cold neutrons is being developed based on the WWR-M operating research reactor at the St. Petersburg Nuclear Physics Institute for research in the field of fundamental physics and nanostructures. Superfluid helium will be used in this source, which should yield a UCN density of 10₄ cm⁻³, which exceeds the density of the currently existing UCN sources (throughout the world) by three orders of magnitude. Having possessed the most intense UCN source, the WWR-M reactor will become an international center of UCN-based fundamental research.     

Heating of ultracold neutrons on beryllium surfaces

The temperature dependence of the loss factor for ultracold neutrons owing to heating at thermal energies on the surface of a beryllium sample is studied. The probability of heating ultracold neutrons is anomalously high throughout the entire measured temperature interval, but especially at low temperatures. Zh. éksp. Teor. Fiz. 114, 786–797 (September 1998)     

Observation of the penetration of subbarrier ultracold neutrons through beryllium foils and coatings

The subbarrier passage of ultracold neutrons through beryllium foils and coatings with a probability much higher than that of tunneling is observed. This effect may be responsible for the so-called anomalous loss of ultracold neutrons. Pis’ma Zh. éksp. Teor. Fiz. 66, No. 5, 317–322 (10 September 1997)     

A liquid hydrogen source of ultra-cold neutrons

A liquid hydrogen source of ultra-cold neutrons (UCN) developed for an experimental search for the electric dipole moment of the neutron is described. The results of an investigation of the yield of UCN from gaseous, liquid, and solid hydrogen as a function of temperature are presented. The UCN counting rate obtained at the output of the 6 × 7 cm² neutron guide tube is 5 × 10⁴ n/s. This counting rate corresponds to a flux of neutrons whose velocity along the axis of the neutron guide tube is below 7 m/s. Preliminary measurements of the UCN yield from liquid and solid deuterium have been carried out.     

High-density ultracold neutron sources for the WWR-M and PIK reactors

It is proposed to equip the PIK and WWR-M research reactors at the Petersburg Nuclear Physics Institute (PNPI) with high-density ultracold neutron (UCN) sources, where UCNs will be obtained based on the effect of their accumulation in superfluid helium (due to the specific features of this quantum fluid). The maximum UCN storage time in superfluid helium is obtained at temperatures on the order of 1 K. These sources are expected to yield UCN densities of 10³–10⁴ cm^–3, i.e., approximately three orders of magnitude higher than the density from existing UCN sources throughout the world. The development of highest intensity UCN sources will make PNPI an international center of fundamental UCN research.