|SUBJECT:||M.S. Thesis Presentation|
|TIME:||Thursday, March 14, 2013, 1:00 p.m.|
|PLACE:||MARC Building, 114A|
|TITLE:||Development And Testing Of An Organic Scintillator Detector For Fast Neutron Spectrometry|
|COMMITTEE:||Dr. Nolan Hertel, Chair (NRE)
Dr. Chris CK Wang (NRE)
Dr. Benjamin Klein (ECE)
The use of organic scintillators is an established method for the measurement of neutron spectra above several hundred keV. Fast neutrons are detected largely by proton recoils in the scintillator which result largely from neutron elastic scattering with hydrogen. This leads to a smeared rectangular pulse-height distribution for monoenergetic neutrons. The recoil proton distribution ranges in energy from zero to the incident neutron energy. In addition, the pulse-height distribution is further complicated by the presence of peaks at higher neutron energies by energy deposition due to alpha particle recoils from interactions with carbon and due to carbon recoils. In order to reconstruct the incident neutron spectrum, the neutron-induced pulse-height spectrum has to be deconvoluted (unfolded) using the computed or measured response of the scintillator to monoenergetic neutrons. In addition gamma rays, which are always present when neutrons are present, lead to Compton electron recoils in the scintillator. Fortunately, for certain organic scintillators, the electron recoil events can be separated from the heavier particle recoil events which can be used to distinguish gamma-ray induced events from neutron-induced events. This is accomplished by using the risetime of the signal from the organic scintillator.