Difference between revisions of "D2O material effect on the neutron asymmetry"

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== MCNPX Results ==
 
== MCNPX Results ==
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A simulation was done using MCNPX to see how neutron scattering impacts asymmetry measurements.  The setup is shown below.  Neutrons were created inside a bottle of D2O and given an initial direction towards the 0 degree detector.  The size of the target and detectors are the actual size used in the experiment.  The distance between the target and each detector is 1 meter. 
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[[File:MCNPX_8_3_pg1.jpg | 600px]]
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A neutron energy distribution was put into MCNPX based off the actual energy distribution from the experimental data. 
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[[File:MCNPX_8_3_pg2.jpg | 800px]]
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The asymmetry results are shown below.
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[[File:MCNPX_8_3_pg3.jpg | 800px]]
  
According to MCNPX, there should be an effect on the neutron asymmetries from neutron scattering. In this simulation, a bottle of D2O was placed 1 meter away from a detector. The detector and the D2O were about the same size as the ones used for the experiment at the IAC. Generating neutrons uniformly inside a plastic container filled with D2O, and given an initial directionality towards the detector, MCNPX gave the following:
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[https://wiki.iac.isu.edu/index.php/PhotoFission_with_Polarized_Photons_from_HRRL back]
 
 
[[File:MCNPX_neutron_scattering.jpg | 400px]]
 
 
 
As the plot shows, fewer of the lower energy neutrons make it to the detector due to scattering within the D2O.  I will run another simulation with more detectors placed at different azimuthal angles as time permits.
 

Latest revision as of 19:06, 3 August 2011

File:Neutron asymmetry.pdf


MCNPX Results

A simulation was done using MCNPX to see how neutron scattering impacts asymmetry measurements. The setup is shown below. Neutrons were created inside a bottle of D2O and given an initial direction towards the 0 degree detector. The size of the target and detectors are the actual size used in the experiment. The distance between the target and each detector is 1 meter.


MCNPX 8 3 pg1.jpg


A neutron energy distribution was put into MCNPX based off the actual energy distribution from the experimental data.


MCNPX 8 3 pg2.jpg


The asymmetry results are shown below.


MCNPX 8 3 pg3.jpg

back