Gamma peak study with in exp. cell with CO-60
Overview
I placed a photon source and trigger at various locations along the beam line, and compared the resulting ToF spectra with a thorium target run. Each ToF spectrum is given a time offset equal to the time light takes to travel from room center to the location of the trigger, e.g. a +3.2 ns shift is applied when the trigger/source is located at the beam dump (see image below). This offsets the effect of moving the trigger with the source.
Results
Determining which gamma peak originates from the thorium target is done by subtracting target-in and target-out data (runs 5320 & 5321). The gamma peak originating from the thorium target can be aligned with the gamma peak measured with a photon source at room center. After this alignment, overlaying thorium target spectrum with the spectra for photons sources at various locations along the beam line reveals the possible origin of the multiple peaks in the spectrum for the thorium target run.
This result offers an explanation for all peaks in the data, except for the particularly problematic peak at 31 ns in detector 270 which overlaps with high energy CF-252 neutrons.
