Difference between revisions of "MCNP Sim of Jack Converter"
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=Results= | =Results= | ||
− | == | + | ==Neutron energy spectra from 42 MeV electrons== |
− | + | ||
The plots below shows the energy distribution for neutrons exiting the converter at three different intervals of their angle w.r.t. the incident electron beam. | The plots below shows the energy distribution for neutrons exiting the converter at three different intervals of their angle w.r.t. the incident electron beam. | ||
The neutron energy spectrum of the neutron-induced fission of U235 is also in each shown for comparison. | The neutron energy spectrum of the neutron-induced fission of U235 is also in each shown for comparison. | ||
+ | |||
The median energy of neutrons from U235 is 1.66 MeV and the mean is 1.94 MeV. | The median energy of neutrons from U235 is 1.66 MeV and the mean is 1.94 MeV. | ||
+ | The mean and median energy of produced neurons are also shown on each plot. | ||
− | === | + | ===Linear, neutron energy>0.13 MeV=== |
− | [[File: | + | [[File:42MeVJackLin n(1).png|1000px]] |
===Misc=== | ===Misc=== |
Revision as of 17:14, 5 September 2018
Simulation inputs
MCNP input deck: File:MCNP Jack Converter.txt.
The cross-section plots below show that the vast majority photo-neutrons are produced by (G,n) on Tungsten-184.
Geometry
Materials legend for figures:
.
Assumptions
The beam spot size was given a diameter of 0.5 cm, which was determined by the size of a burn mark on a converter that got hot during irradiation. Electrons are 42 MeV and mono energetic.
Results
Neutron energy spectra from 42 MeV electrons
The plots below shows the energy distribution for neutrons exiting the converter at three different intervals of their angle w.r.t. the incident electron beam. The neutron energy spectrum of the neutron-induced fission of U235 is also in each shown for comparison.
The median energy of neutrons from U235 is 1.66 MeV and the mean is 1.94 MeV. The mean and median energy of produced neurons are also shown on each plot.
Linear, neutron energy>0.13 MeV
Misc
The difference between the U235 neutron spectrum and the energy spectrum from the converter may be partially due to moderation of neutrons by H2O. The plot below demonstrates this point, which registers the energy of each photo-neutron immediately after emission, as opposed to after the photo-neutrons exit the converter.
Below is a plot of the rate of neutron production as the beam traverses through the converter. Zero corresponds to where the beam enters the titanium window.
Photons
The plot below shows the energy distribution of photons exiting the converter at three different intervals of their angle w.r.t. the incident electron beam