The Calibration of the DD Neutron Indium Activation Diagnostic

The indium activation diagnostic was calibrated using an accelerator neutron source to facilitate the diagnosis of deuterium-deuterium (DD) neutron yields of implosion experiments in the Shenguang-III facility. The scattered neutron background of the accelerator room was measured by placing a polypropylene shadow bar in front of the indium sample, so as to correct the calibrated factor of this activation diagnostic. The proper size of the shadow bar was given by Monte Carlo simulation. The calibration results showed that the scattered neutron background of the accelerator room was about 9% of the incident neutrons on the sample. Subtracting the portion induced by the neutron background, the calibrated factor for this sample condition was 4.52×10⁻⁷ counts/n with an uncertainty of 4.3%. (paper)