An experimental study of 256Rf spontaneous fission following the fusion reaction of 50Ti+208Pb was performed using the velocity filter SHELS of the Flerov laboratory at JINR. The average number of ...neutrons of ν‾=4.30±0.17 and variance of σν2=3.2 from the prompt neutron multiplicity distribution were obtained. The alpha decay branching ratio of bα=0.003−0.003+0.005 and the half-life of T1/2=(6.7±0.2) ms of the isotope were determined. For the first time, our neutron detector system allowed us to extend investigation of the prompt neutron multiplicity study to the superheavy element region.
At present, in the Joint Institute for Nuclear Research (JINR), Dubna, Russia, experiments to study the process of inelastic scattering of fast neutrons with the nuclei of various substances are ...being conducted in the frame of the TANGRA (TAgged Neutron and Gamma RAys) project.
The existing TANGRA facility allows to obtain precise information about the angular and energy distributions of gamma-rays resulting from the inelastic scattering of 14.1 MeV neutrons on complex nuclei.
As source of neutrons, we used a portable neutron generator ING-27 (En=14.1MeV), designed and created by VNIIA (Moscow) with an embedded double-sided 64-pixel silicon (gallium arsenide) alpha-particle detector, by means of which 64 independent tagged neutron beams are formed.
Tagging of neutrons is done by registration of the alpha particle, produced in the binary reaction d + t → (α + n), which is emitted in direction almost opposite to that of the neutron.
To obtain correct information about the characteristics of the process of inelastic neutron scattering on nuclei, it is necessary to know the parameters of all 64 tagged neutron beams with good accuracy.
To solve this problem, we have developed and created a two-coordinate position-sensitive silicon detector of fast neutron (profilometer), by means of which we measured the characteristics of all the 64 tagged neutron beams.
In this paper we give a description of the design of the profilometer and present the results from the measurements of profiles of 64 tagged neutron beams formed by ING-27.
The SFiNx Detector System Isaev, A. V.; Yeremin, A. V.; Zamyatin, N. I. ...
Physics of particles and nuclei letters,
02/2022, Letnik:
19, Številka:
1
Journal Article
Recenzirano
Odprti dostop
A new detector system for investigating the properties of spontaneous fission of short-lived transuranium nuclei has been created. This system consists of an assembly of double-sided silicon strip ...detectors surrounded by 116 proportional neutrons counters filled with
3
He. The neutron registration efficiency is 54.7 ± 0.1%. The detector system is tested in an experiment investigating the characteristics of spontaneous fission of the
252
No isotope. The experimental data on neutron yields are compared with previously published results. The average number of neutrons per fission act (
= 4.25
0.09) and the multiplicity distribution of prompt neutrons are obtained. The true form of the neutron distribution is reconstructed via a statistical regularization.
The results obtained by measuring the angular and energy distributions of gamma rays originating from the inelastic scattering of 14.1-MeV neutrons by carbon and oxygen nuclei are presented. The ...measurements in question were performed by the tagged-neutron method in a beam of an ING-27 standard portable neutron generator. The angular distributions of gamma rays emitted by the 2
+
state of
12
С at 4.43 MeVand the 3
−
state of
16
O at 6.13 MeV were obtained.
The characteristics of detectors made of silicon carbide (SiC) irradiated with various integral fluxes of both Xe ions with an energy of 165 MeV and fast neutrons were studied. With the help of
...-particles, it was found that the energy resolution of SiC detectors irradiated with the maximum fluxes of heavy ions (
ion/cm
) and neutrons (
n/cm
) deteriorates by an order of magnitude. It was shown that the efficiency of detector charge collection decreases to 70 and 5
, respectively, upon irradiation with Xe ions and neutrons.
The characteristics of detectors based on silicon carbide (SiC) before and after irradiation with integral neutron fluxes of 5.11 × 10
13
and 5.39 × 10
14
n/cm
2
are presented. On the samples ...irradiated with the maximum fluence, using alpha particles, a deterioration in the energy resolution by an order of magnitude and a decrease in the efficiency of charge collection by ∼25% are shown.
The results obtained by measuring the angular and energy distributions of gamma rays produced in reactions induced by the inelastic scattering of 14.1-MeV neutrons on sup.27Al nuclei are presented. ...The respective measurements were performed by the tagged-neutron method in a beam from the ING-27 compact neutron generator. The angular distributions were obtained for gamma rays emitted from the 844-keV 1/2.sup.+, 1015-keV 3/2.sup.+, 2212-keV 7/2.sup.+, and 3004-keV 9/2.sup.+ states of sup.27Al nuclei.
The results obtained by measuring the angular and energy distributions of gamma rays produced in reactions induced by the inelastic scattering of 14.1-MeV neutrons on
27
Al nuclei are presented. The ...respective measurements were performed by the tagged-neutron method in a beam from the ING-27 compact neutron generator. The angular distributions were obtained for gamma rays emitted from the 844-keV 1/2
+
, 1015-keV 3/2
+
, 2212-keV 7/2
+
, and 3004-keV 9/2
+
states of
27
Al nuclei.
The results of measurements of 1-MeV (Si) equivalent fast neutron fluence with silicon planar detectors are reported. The measurement method is based on the linear dependence of the reverse detector ...current increment on the neutron fluence: ΔI = α
I
× Φ ×
V
. This technique provides an opportunity to measure the equivalent fluence in a wide dynamic range from 108 to 10
16
cm
–2
with an unknown neutron energy spectrum and without detector calibration. The proposed method was used for monitoring in radiation resistance tests of different detector types at channel no. 3 of IBR-2 and for determining the fluence of fission and leakage neutrons at the KVINTA setup.
