View source for D2O photodisintegration simulation

[[File:D2O_photodis.pdf]]

[[File:dustin_anal.pdf]]

The result of GEANT4 simulation of neutron photoproduction on deuterium and oxygen-16 is presented below:

[[File:X_section_compare.gif | 650 px]]


Neutron yield (<math>4\pi</math>) from  <math>D_2O</math> (90%<math>D_2</math> concentration) in reaction <math>O16(\gamma,n)O15</math> is presented below. 410 neutrons initially produced got absorbed in the target (E=0MeV) and 2509 neutrons will likely escape the target. Figure in blue on the left is the total energy spectrum of neutrons created in reaction <math>O16(\gamma,n)O15</math>. Figure in blue on the right is the neutron energy spectrum with energy cut applied.

[[File:O16_neutron_yield.gif | 500 px]] [[File:O16_neutron_yield_cut.gif | 500 px]]

Neutron yield (<math>4\pi</math>) from  <math>D_2O</math> (90%<math>D_2</math> concentration) in reaction <math>D_2(\gamma,n)p</math> is presented below. 857 neutrons initially produced got absorbed in the target (E=0MeV) and 16799 neutrons will likely escape the target. Figure in black on the left is the total energy spectrum of neutrons created in reaction <math>D_2(\gamma,n)p</math>. Figure in blue on the right is the neutron energy spectrum with energy cut applied.

[[File:D2_neutron_yield2.gif | 500 px]] [[File:D2_neutron_yield_cut.gif | 450 px]]

So, if we apply the energy cut in neutron spectrum which is a sum of neutrons coming from <math>O16(\gamma,n)O15</math> and <math>D_2(\gamma,n)p</math> reactions at (0MeV)<E<=5MeV, then the ratio of unpolarized photons from <math>O16(\gamma,n)O15</math> and polarized photons from <math>D_2(\gamma,n)p</math>  will be <math>855/15128=0.056</math>. In the same time we will loose <math>(16799-15128)/15128=11%</math> of the "good" neutrons produced in <math>D_2(\gamma,n)p</math> reaction.