Application of Physical Methods for Reducing Plutonium Hexafluoride

The exploding-wire method, the photochemical method of irradiation with a light flux from a high-pressure mercury lamp, a high-intensity spark discharge, and irradiation by a CO₂ laser are used to reduce plutonium hexafluoride and to separate it from uranium hexafluoride. The dependence of the reduction of plutonium hexafluoride on the wire material, the mass of the reduced product, and the amount of input energy is investigated.It is shown that the methods presented for reducing plutonium hexafluoride and separating it from uranium hexafluoride can be used under static and dynamic conditions for preparative purposes and on a large scale.     

Fractures of Structural Steels (Part 2)

Fractures of group II (according to the classification given in Part 1) are described in detail. The deviations of the structure of a fracture from the groups of fiber and crystalline fractures are explained by the chemical micro- and macroinhomogeneity of the metal. The characteristics of fractures, the causes of their formation, the methods for fighting and eliminating them, and the interrelation with the mechanical properties of the steel are described. Every kind of fracture is illustrated.     

Ultracold neutron cooling upon reflection from a moving wall

The process of neutron cooling upon adiabatic increase in the storage volume has been studied on an ultracold neutron beam of the ILL reactor. The cooling of neutrons in the course of magnetic trap filling allows the number of stored neutrons to be significantly increased and, hence, the statistical accuracy of determination of their lifetimes to be improved.     

Permanent-magnet trap for ultracold neutron storage

The design of a permanent-magnet trap for ultracold neutron (UCN) storage is described. This trap excludes neutron collisions with the walls and, hence, eliminates anomalous losses. Used in the experiments on the neutron lifetime determination such UCN traps remove the main systematic error related to the anomalous neutron losses on the walls.