[en] The device is applicable in experimental neutron physics for investigation of the optical and electromagnetic properties of the neutrons. It has reduced dimensions and increased efficiency of focusing and registration of the ultracold neutrons. The device consists in cylindrical mirror with vertical ax, two plano-parallel mirrors, inlet and outlet for ultracold neutrons. 2 cls., 2 figs

[en] The total cross sections of U-233, U-235 and Pu-239, the fission and radiative capture cross sections of U-235 and Pu-239 were measured by the time-of-flight method with time resolution of 40 and 55 ns/m using the JINR pulsed fast reactor. The liquid boron scintillation detector was used to detect the resonance neutrons in the measurements of the total cross sections by the transmission method. The measurements of the total cross sections and that of fission and radiative capture by the self-indication method were carried out using a large cadmium-loaded liquid scintillation detector. The parameters gΓ_n, Γ, Γ_f and Γ_c for 78 levels of U-235, 32 levels of Pu-239 and the parameters gΓ_n for 13 levels of U-233 were calculated by the area method. In recent years the investigations of resonance neutron interactions with fissionable nuclei by the time-of-flight method using the pulsed neutron spectrometer are being developed /l, 2,3/. They are stimulated both by growing demands to the accuracy of the partial neutron cross section measurements and by the possibility of comparing different experimental characteristics of the interaction process itself, and, in particular, of the fission process, with the theoretical nuclear models.

No abstract available

[en] A multilayer ionization fission chamber (IFC) with the fissionable targets and operating gas cooled down to the temperature of about 77⁰K is described. The results of the investigation of the multilayer ionization fission chamber with the operating gas mixture of Ne(70%) + He(23%) + N(7%) are presented. It is shown that the performance of the chamber does not change with the cooling of the targets and gas down to the temperature of liquid nitrogen

[en] Counting characteristics of multifilament spark detector (SD) for α-particles and fission fragments are presented. It has been found that irradiation of SD with γ-rays resulted in increasing the detection threshold for α-particles. A method is proposed for decreasing the dead time(tau m) for SD, that has been tested under real operation conditions in a reactor. It has been found that tausub(m) < or approximately 80 msec

[en] Using the method of multiplicity spectrometry the α thermal value for ²³⁵U is measured. The experiment is carried out using a neutron beam from a research reactor. The value α thermal=0.1690±0.0035 is obtained. Total measurement error is approximately equal to 2%

[en] The mean kinetic energy anti Esub(k) of fission fragments in the energy range Esub(n) (<=) 0.0052 eV above the negative resonance is found to be approximately 0.1 MeV higher than that for a resonance energy Esub(n) =0.29 eV. The values of anti Esub(k) and spins are analysed for the resonances

[en] The set up BRIK for performing at the IBR-2 pulsed reactor many parameter investigations of the fission process of heavy nuclei is created. The detector apparatus, the measuring module equipment on the base of a mini-computer and apparatus in the CAMAC standard are described as well as software which enables one to execute automatically the experiment program, to control the measuring module operation, to store physical information at external carriers and its whole mathematical treatment. Two silicon surface-barrier big area detectors and ₂₃₅U thin spectroscope target have been used. For analog-to-digital data conversion a time-coder of the VK5 type and two of the AK1024-type amplitude coders mounted on the CAMAC crate have been used. The management of the crate magistral is realized through a special controller. Fission fragments mass distribution and whole fragments kinetic energy distribution for six mass intervals in separate resonances are obtained

No abstract available

[en] The angular distribution of ²³⁵U fission fragments is measured. The experimental distribution is approximated by the function W(THETA) = 1 + A cos²THETA, where A(anisotropy) = -(1.8 +- 1.6)x10^-2. It is shown, that the negative sign of anisotropy is determined by fission via the channels with Jsup(π) = 2⁺ and 4⁺ (K=2)