Thermal analysis, design, and testing of a rotating beam target for a compact D-D fast neutron generator.

Abstract Compact Deuterium-Deuterium fast neutron generators are generally limited to a low neutron yield due to outgassing of implanted deuterium in case of ion beam target overheating. This is even more pronounced for a generator with a small emitting spot tailored to transmission-based imaging applications, resulting in long exposure times. In this work a novel water-cooled rotating copper target rod with a 5 µm thin titanium coating as a deuteron beam target was developed. Using extensive computational fluid dynamics and heat transfer analysis, an optimized target configuration was chosen. The details of the target rod design, construction and loading with deuterium are outlined. The first results after loading showed a peak total neutron output of 4.8 × 107 n/s for −107 kV target high voltage and 0.9 mA average target current at 220 rpm target rotational velocity. The comparison between actual and theoretical ideal neutron yield suggested that no loss of deuterium density in the target due to outgassing occurred. Highlights • Computational fluid dynamics and heat transfer analysis of a water-cooled rotating deuteron beam target. • Mechanical design of the high voltage rotating target rod and support structure. • Novel target design achieving a neutron output of 4.8 × 107 n/s at −107 kV target voltage and 0.9 mA beam current. • Experiments indicated that the titanium deuteride surface successfully remained below the degassing temperature. [ABSTRACT FROM AUTHOR]