Neutron Yield of Thermo Scientific P385 D–T Neutron Generator Versus Current and Voltage

The Thermo Scientific P385 Neutron Generator is a compact neutron source, producing 14-MeV neutrons through the deuterium-tritium (D-T) fusion reaction. It is important to measure and understand the dependence of the neutron production rate on the accelerator current and voltage. In this study, we evaluated neutron production with an absolutely calibrated liquid scintillator neutron spectrometer (BTI N-Probe), an absolutely calibrated He-3 detector surrounded by high-density polyethylene (HDPE) shells [Detec nested neutron spectrometer (NNS)], and two uncalibrated zinc sulfide (ZnS) fast neutron scintillators (EJ-410), for both A3082 and A3083 sealed tubes. We also modeled the neutron yield using the Transport of Ions in Matter (TRIM) code, which calculates the trajectory and the energy loss of deuterons and tritons in the target. Experimental results showed an essentially linear dependence on the beam current, as expected. A $3.59~\pm ~0.08$ power law dependence on the operating voltage was measured, in effective agreement with the modeled value of 3.5. A series of absolute NNS and N-Probe measurements, matched against Monte Carlo N-Particle (MCNP) calculations, showed that the A3083 and A3082 tubes provide a maximum neutron yield of $ 8.2 \times 10^{8}$ and $4.7 \times 10^{8}$ n/s, respectively, with an estimated uncertainty of ±10%. We showed, through modeling, that tritium decay is not a significant consideration for tubes, such as these, with lifetimes of less than ten years.