[en] The inclusive spectra of neutrons from reactions initiated by helium-, lithium- and carbon ions at energies above the Coulomb barrier from 1.6 up to 16 MeV/nucl. are analyzed. The neutrons are produced in the reaction with carbon at 1.6 MeV/nucl. energy as a result of evaporation from a compound nucleus. In all the other reactions the spectra deviation from the equilibrium behaviour is observed. Differential cross sections of neutron production were analyzed twice with the use of representation on the existence of angular-distributed energetic neutron sources. The obtained widths of non-equilibrium neutron, energy distributions cannot be explained by the simplest theories of projectile fragmentation and breakup reactions. These widths are explained in the framework of the exiton- and hybrid models of preequilibrium decay; the models correctly reproduce the form of experimental neutron distributions integrated over the angles, but do not coincide with them in the cross section absolute values. The relaxation times (1-4)x10^-22 determined with the use of the hot spot model are in good agreement with the data obtained from the exiton model calculation. The period of the most intensive non-equilibrium emission turned out to be (1.5-3.5)x10^-23 s in the hot spot representation and 4x10^-23 s in the exiton representation. Comparison of the preequilibrium neutrons yield cross sections shows a possibility of the existence of the unified mechanism of preequilibrium decay in collisions with both heavy ions and light particles

[en] A possible way is described of complete processing of measurement of neutron spectra by the time-of-flight method. To ensure reliable finding of peaks a method is applied providing effective smothing of spectra in which the number of counts in a channel may change sharply. It has been established that the Newton method modified for the given problem makes it possible to obtain the solution after a few (approximately 10) iterations. Using the above procedure one can discriminate from a spectrum and process nonsymmetric peaks corresponding to resonances with an intrinsic width exceeding the spectrometer resolution. The program for processing of experimental spectra automatically separates monochromatic neutrons from those of a continuous spectrum, calculates neutron energies and the differential cross sections of their yield, and converts the values found to the centre-of-mass coordinate system

[en] On the isochronous cyclotron of the I. V. Kurchatov Atomic Energy Institute measurements of cross sections and angular distributions for neutron channels of 8.6 and 11.2 MeV alpha-particle interactions with lithium-6 and lithium-7 have been carried out. The results obtained have been analyzed and compared with those published earlier

[en] The decay of 2⁺ excited state of ⁶He nucleus produced in ⁷Li(d, ³He)⁶He* reaction at deuteron energy of 30.5 MeV, is studied experimentally. Measurements have been performed at the IAEh isochromous cyclotron. A target made of metallic lithium has been used. Recording and identification of α particles and ³He has been carried out by two silicon telescopes with the help of the fast-slow coincidance method. Experimental spectra of α particles of ⁶He* decay are presented in laboratory coordinate system (LCS). The spectra calculation of α particles in LCS has been carried out by the Monte Carlo method. Itis shown that the mechanism of dineutron emission ²n(T=1, S=0) explains 45% events of decay

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No abstract available

[en] The decay of ⁶Be nucleus excited state is studied. The ⁶Li(³He, t)⁶Be⁶ reaction with ³He ions energy of 38.7 MeV has been used to produce ⁶Be nuclei. α particles producing during the ⁶Be decay has been detected under the angle of 25.4 deg in coincidence with tritium nuclei, in the spectrum of which two peaks are distictly singled out, characterizing ⁶Be formation in O⁺ and 2⁺ states. A spectrum of α particles out of ⁶Be* decay in laboratory coordinate system is presented. In 25% of events the decay is manifested by ²He emission

No abstract available

No abstract available

[en] The 1.5-meter isochronous cyclotron of the Kurchatov Nuclear Energy Institute with the time-of-flight spectrometer is used to measure energy spectra and angular distributions of neutrons appearing in reactions ⁶²Ni+ ³He, ⁴Ni+α, ⁵⁹Co+⁶Li and ⁵³Cr+¹²C. At the energy of incident particles 10-15 MeV/nucl. experimental results prove the presence of a considerable share of high energy neutrons in the general spectrum emitted by nuclei preliminarily in the forward direction