Calculated neutron spectra from 9Be(α, n) sources

1968 ◽  
Vol 46 (13) ◽  
pp. 1527-1536 ◽  
Author(s):  
L. Van der Zwan
Keyword(s):  
Simple Model ◽  
Neutron Spectrum ◽  
Neutron Yield ◽  
Cluster Size ◽  
Energy Losses ◽  
Neutron Spectra ◽  
N Sources ◽  
Similar Peak ◽  
Α Particles

The neutron spectra from 9Be(α, n) sources are calculated for the α emitters 241Am, 210Po,and 239Pu. For a Pu–Be source, peaks are found at neutron energies of 0.75, 1.20, 2.10, 3.15, 4.95, 6.50, 7.75, and 9.65 MeV. Similar peak positions are found for sources made with 241Am and 210Po. The effect of the α-energy losses in the α-emitting material is studied by means of a simple model consisting of clusters of the α-emitting material embedded in a matrix of beryllium. For sources composed of clusters of AmBe13 or PuBe13 in beryllium, the changes in shape of the neutron spectrum are minor as the cluster size is increased from 0.5 to 20 μ. However, for sources consisting of clusters of Pu and Am or Po embedded in beryllium, the spectrum is considerably distorted as the cluster size is varied from 0.5 to 10 μ. The neutron yield per 106 α particles is calculated for sources having Am, Po, or Pu clusters ranging in size from 0 to 20 μ and AmBe13 or PuBe13 clusters ranging from 0 to 40 μ. The percentage of neutrons below 1.5 MeV including the contribution from the multiparticle reaction 9Be(α, αn)8 Be is estimated to be 16% for an AmBe13 type of source and 12% for a PuBe13 type of source, each with a cluster size of 0.5 μ.

scholarly journals A detailed study of the "radioactive decay" of, and the penetration of α-particles into, a simplified one-dimensional nucleus

1929 ◽  
Vol 124 (795) ◽  
pp. 493-501 ◽  
Keyword(s):  
Simple Model ◽  
Common Knowledge ◽  
Radioactive Decay ◽  
Particle Emission ◽  
Decay Process ◽  
Characteristic Energy ◽  
One Dimensional ◽  
Reverse Process ◽  
The Law ◽  
Α Particles

1. Introduction .—Gamow's elegant deduction by general arguments of the law of radioactive decay by α-particle emission and his subsequent investigations on artificial disintegration suggested to us the desirability of investigating as closely as possible any simple model of a decaying nucleus as a verification of his general approximations. For the model chosen the exact investigation of the decay process is almost trivial. Since we obtained this, now some time ago, Dr. Gamow informed us that he had also obtained equivalent detailed results. Still more recently such results have been published by Kudar. We shall not therefore dwell upon them here. The application of the same ideals, however, to the reverse process of penetration presents points of very definite interest, which we think are well worth discussion. The main point that arises is that the chance of penetration α-particle is or is not equal to a characteristic energy of the nucleus itself. This is a point which is not dealt with by Gamow in his paper. We have discussed it with him, and now put forward the results we have obtained. Since the solution of the decay problem is required in the main discussion of the penetration of α-particles into the nucleus it is included here in 2 for reference. We must emphasise that we claim no novelty, except of detail, for the work of 2; the general lines by now are a matter of fairly common knowledge.

Increases in Neutron Yield of239Pu-Be(α, n) Sources—II

1981 ◽  
Vol 52 (3) ◽  
pp. 428-430 ◽  
Author(s):  
M. E. Anderson
Keyword(s):  
Neutron Yield ◽  
N Sources

Study on the Measurement of U-238 Neutron Yield Base on the Fission Chamber

2011 ◽  
Vol 366 ◽  
pp. 474-477
Author(s):  
Ju Mei Ai ◽  
Qiang Wang
Keyword(s):  
Neutron Yield ◽  
Ionization Chamber ◽  
Measurement Method ◽  
Fission Neutron ◽  
Particle Energy ◽  
Measuring System ◽  
Fission Chamber ◽  
Particle Counts ◽  
Yield Monitoring ◽  
Α Particles

This paper discusses a variety of fission neutron yield measurement method, a D-T / D-D neutron yield monitoring of U-238 fission ionization chamber measuring system, the application of spontaneous decay of U-238 α-particles for initial debugging of the system. At different voltage on the α-particle energy spectrum and α particle counts were measured, given the U-238 fission chamber curve to determine the U-238 fission chamber measurement system the best operating parameters.

Neutron spectra from isotopic (?, n) sources

1973 ◽  
Vol 34 (5) ◽  
pp. 436-440
Author(s):  
N. D. Tyufyakov ◽  
L. A. Trykov ◽  
A. S. Shtan'
Keyword(s):  
Neutron Spectra ◽  
N Sources

scholarly journals Analysis of cross sections on iron and oxygen using Cf-252 neutron source

2020 ◽  
Vol 239 ◽  
pp. 18005
Author(s):  
Bohumil Jansky ◽  
Jiri Rejchrt ◽  
Evzen Novak ◽  
Anatoly Blokhin
Keyword(s):  
Cross Section ◽  
Neutron Source ◽  
Neutron Spectrum ◽  
Heavy Water ◽  
Cross Sections ◽  
Energy Region ◽  
Nuclear Data ◽  
Data Section ◽  
Neutron Spectra ◽  
Artificial Changes

The leakage neutron spectra measurements have been done on benchmark spherical assemblies with Cf-252 source in center of 1) heavy water sphere with diameter of 30 cm (with Cd cover) and of 2) iron spheres with diameter of 100 cm and 50 cm. It has been stated for years that transport calculations by iron overestimate measured spectra in energy region around 300 keV by about 20-40 % (calculation to measurement ratio C/E = 1.2-1.4). The influence of an artificial changes in cross-section XS-Fe-56 (n,elastic)designed by IAEA, Nuclear Data Section, has been studied on the iron spheres. Influence of those XS-corrections to calculated neutron spectrum is presented.

scholarly journals CHARACTERIZATION AND COMPARSION OF NEUTRON GENERATORS OF IEC AND LINEAR D-T BY THE SPECTROMETRIC SYSTEM NGA-01

2021 ◽  
Vol 247 ◽  
pp. 18004
Author(s):  
Zdenek Matej ◽  
Michal Kostal ◽  
Evzen Novak ◽  
Petr Alexa ◽  
Radim Uhlar ◽  
...  
Keyword(s):  
Neutron Spectrum ◽  
Neutron Energy ◽  
Pulse Height ◽  
Likelihood Estimation ◽  
Voltage Divider ◽  
Neutron Spectra ◽  
Energy Peak ◽  
Neutron Generators ◽  
Mixed Fields ◽  
Spectrometric System

This article focuses on description of two different neutron fields from linear and cylindrical Inertial Electrostatic Confinement (IEC) neutron generators. Both of these generators are well defined and commonly used. They use a deuterium-tritium reaction that produces neutrons with energies in the range 13 – 16 MeV, depending on the direction and the energy of the incoming deuterium nucleus. Two-parametric spectrometric system for neutron/gamma mixed fields NGA-01 was used to characterize neutron spectra in the proximity of generators. The cylindrical 45x45 mm stilbene scintillator was connected to this device using an active voltage divider. This way, we were able to measure neutron energies in the range 1 - 15 MeV while filtering out gamma radiation, even when counts per second is high. For the neutron spectrum calculation recoil spectra using deconvolution through maximum likelihood estimation was used. Measured neutron spectra have been compared with simulations realized via MCNP6. According to the theoretical prediction, these two types of generators produce different neutron fields. In case of the linear generator the target is very close to point located tritium bombarded by deuterons. Thus the neutron spectrum varies depending on the angle between the detector axis and the axis of the generator. Both experimental results and simulation show a shift of the neutron energy peak in pulse height histogram. For IEC type generators the neutron spectrum is more complicated. The shape and the position of the neutron energy peak depend heavily on the position of the detector. The most prominent effect is in the position in the plane perpendicular to the generator axis. In this case, the peak splits into two peaks that can be measured and distinguished. These results were verified by the diamond detector which was also used for characterization of the IEC type generator.

Neutron yield from the reaction (α, n) in Be, B, C, O, F, Mg, Al, Si, and granite irradiated with polonium α particles

Atomic Energy ◽  
1963 ◽  
Vol 13 (1) ◽  
pp. 654-657 ◽  
Author(s):  
G. V. Gorshkov ◽  
V. A. Zyabkin ◽  
O. S. Tsvetkov
Keyword(s):  
Neutron Yield ◽  
Α Particles

Solar Chimney Cycle Analysis With System Loss and Solar Collector Performance

2000 ◽  
Vol 122 (3) ◽  
pp. 133-137 ◽  
Author(s):  
Anthony J. Gannon ◽  
Theodor W. von Backstro¨m
Keyword(s):  
Experimental Data ◽  
Simple Model ◽  
Power Plant ◽  
Kinetic Energy ◽  
Solar Collector ◽  
Large Scale ◽  
Small Scale ◽  
Energy Losses ◽  
Solar Chimney ◽  
Solar Chimney Power Plant

An ideal air standard cycle analysis of the solar chimney power plant gives the limiting performance, ideal efficiencies and relationships between main variables. The present paper includes chimney friction, system, turbine and exit kinetic energy losses in the analysis. A simple model of the solar collector is used to include the coupling of the mass flow and temperature rise in the solar collector. The method is used to predict the performance and operating range of a large-scale plant. The solar chimney model is verified by comparing the simulation of a small-scale plant with experimental data. [S0199-6231(00)00503-7]

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