Fission probabilities of Cu,Nb, Ag,Ho, Au and Bi nuclei excited by stopped antiprotons

The A dependence of nuclear fission induced by stopped antiprotons has been measured. An unambiguous identification of the binary fission decay mode was provided by a coordinate measurement of complementary fission fragments in coincidence using a large-acceptance fission detector based on low pressure multiwire proportional chambers. A deep fissility minimum was observed nearA=100, in agreement with the general behaviour predicted by the liquid-drop model. An unexpectedly low and high fission probability was found for the Ag and Cu nuclei, respectively.     

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.     

L-homomorphisms of locally solvable,torsion-free groups

Mathematical Notes -     

On a theory of spin systems with competing anisotropies

On the basis of a quantum treatment of Me_1?cFe_cX (Me = Mn, Ni, Co, X = Cl₂, CO₃, etc.) type random systems it is shown that parallel with order parameters such as magnetizations of mixed magnetic crystal ordering subsystems there is one more order parameter determining the angle between them.     

Reaction of N-chloromethyldiethylamine,N-chloromethylbenzamide,N-chloromethylphthalimide with amides of trivalent phosphorus acids

Conclusions In the series of N-chloromethylphthalimide, N-chloromethylbenzamide, N-chloromethyldiethylamine, in reactions with amides of trivalent phosphorus acids, the contribution of the reaction at the phosphorus atom increases with increase in the polarity of the C-Cl bond. N-Chloromethylphthalimide, whose C-Cl bond is least polar in this series, reacts with hexaethyltriamidophosphite and diethylamidodiphenylphosphinite reacts at the N and P atoms to form the corresponding quasiphosphonium salts and acid chlorides of trivalent phosphorus acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 173–178, January, 1985.