249 research outputs found
Manifestation of one- and two-body currents in longitudinal and transverse response functions of the 12C nucleus at q = 300 MeV/c
The experimental values of longitudinal and transverse response functions of
the 12C nucleus have been obtained at the 3-momentum transfer q = 300 MeV/c.
The data are compared with the calculations made with due regard to the
dynamics of all the nucleons constituting the 12C nucleus, and also, to the
contributions of both the one-body currents only, and their combination with
two-body currents.Comment: 4 pages, 2 figure
Saturation of Coulomb sum rules in the 6^Li case
The Coulomb sums S_L(q) of the 6^Li nucleus have been obtained from electron
scattering measurements at 3-momentum transfers q = 1.125 - 1.625 fm^{-1}. It
is found that at q > 1.35 fm^{-1} the Coulomb sum of the nucleus becomes
saturated: S_L(q) = 1.Comment: 6 pages, 4 figures, 1 tabl
Designing of phantom head used in optical diagnostics of brain injury
This article shows the results of an experimental research on properties of the materials chosen for designing of a phantom head, which is to be used in testing of a brain hematoma diagnostics device. We have conducted a comparative research of the optical properties of model materials and real head tissue
The Coulomb sum of 7Li
The experimental values of longitudinal response function of the 7Li nucleus have been obtained and these results have been used as the basis to find the Coulomb sum values at momentum transfers ranging from 0.55 to 1.625 fm-1. The obtained experimental Coulomb sum values have been used to determine the total Coulomb energy of the 7Li nucleus. The result of the comparison of the Coulomb energy for the 7Li nucleus with the Coulomb energies for the 6Li and 4He nuclei a) is consistent with the paradox (revealed in the elastic electron scattering experiment) that the 7Li rms charge radius is smaller than the one of the 6Li nucleus; b) leads to the conclusion that, within the framework of the two-cluster model of the 7Li nucleus (α + t), the size of the α-cluster should be larger than the one of the 4He nucleus
Cross-sections for the multiparticle reaction at = 40 95 MeV
The bremsstrahlung flux-averaged cross-sections and the cross-sections per equivalent photon
were measured for the
photonuclear multiparticle reaction at bremsstrahlung end-point
energies ranging from 40 MeV to 95 MeV. The experiments were performed using
the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of
the -activation technique. The bremsstrahlung quantum flux was
calculated with the program GEANT4 and, in addition, was monitored by means of
the reaction. The cross-sections
were computed using the TALYS1.9 code with the default options. The
measured average cross-sections
and have appeared to be
higher by factors of 2.0 to 2.4 than the theoretical results. The experimental
results have been found to be in good agreement with the data of other
laboratories. Consideration is given to special features of calculation of
and for the
reaction, with occurrence of
three photodisintegration channels. The paper also discusses
the possibility of using the
reaction for monitoring the bremsstrahlung -quantum flux in the photon
energy region above 30 MeV.Comment: 16 pages, 6 figures, 1 tabl
Electrophysical methods of separation of metal cations in the moving salts solution
The results of experiments on the excitation of the phenomenon of selective drift of solvated ions under the influence of an external "asymmetric" electric field to the circulating solution of calcium chloride and magnesium salts in a polar liquid dielectric - water are shown. The purpose of the experiments was to determine the influence of the field frequency and amplitude of the field strength on the excitation phenomenon, and the study of the operating characteristics of the testing apparatus - a dividing cell. The dependences of the separation efficiency of solvated cations from the frequency of the external field and the excitation threshold of the phenomenon from the field strength in the separation cell are defined
Photonuclear reactions cross-sections at energies up to 100 MeV for different experimental setups
In experiments on the electron linac LUE-40 of RDC "Accelerator" NSC KIPT,
the flux-averaged cross-sections of photonuclear reactions
,
,
,
, and
were measured using the
-activation technique. The theoretical flux-average cross-sections
were computed using the
partial cross-section values from the TALYS1.9-1.95 codes and
bremsstrahlung -flux calculated using GEANT4.9.2. Two different
experimental setups were used in the experiments: an aluminum electron absorber
and a deflecting magnet to clean the bremsstrahlung -flux from
electrons. A comparison of the flux-average cross-sections measured for two
experimental setups was performed. The possibility of using the reactions
,
,
,
, and
as monitors of the bremsstrahlung
-flux for the energy range 30-100 MeV was investigated.Comment: 8 pages, 6 figures, 1 tabl
Isomeric pair in photonuclear reactions on Mo at end-point bremsstrahlung energy of 35-95 MeV
The Nb photonuclear reaction
was studied using the electron beam from the NSC KIPT linear accelerator
LUE-40. Experiment was performed using the activation and off-line -ray
spectrometric technique. The experimental isomeric yield ratio was
determined for the reaction products at the end-point
bremsstrahlung energy range of 35-95 MeV. The obtained
values of are in satisfactory agreement with the
results of other authors and extend the range of previously known data. The
theoretical values of the yields and the
isomeric yield ratio for the isomeric pair from the reaction were
calculated using the partial cross-sections from the TALYS1.95 code
for six different level density models . The comparison showed a noticeable
excess (more than 3.85 times) of the experimental isomeric yield ratio over all
theoretical estimates. At the investigated range of the
theoretical dependence of on energy was confirmed -
the isomeric yield ratio smoothly decreases with increasing energy.Comment: 9 pages, 9 figures, 1 tabl
Magnetic system for cleaning the gamma beam at the LUE-40 electron linac output
The bremsstrahlung of accelerated electrons passing through a converter is
used to study multiparticle photo-nuclear reactions. The results of
calculations, numerical modeling, design, and testing of a special magnetic
cleaning system to obtain a "pure" beam of bremsstrahlung quanta when studying
the cross-sections of such reactions at the LUE-40 linac are presented. The
system is based on commercially available permanent magnets of rectangular
cross-sections. The maximum on-axis field is 0.9 T, which provides sufficient
separation of the electron beam and gamma rays at a distance of more than 90 mm
from the magnet.Comment: 9 pages, 8 figure
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