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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]

A compact D-D fast neutron generator system was developed with an emphasis on imaging applications. It is equipped with an electron cyclotron resonance microwave ion source, an electric field method electron suppression electrode, and a rotating beam target. The design, mechanical assembling, and initial performance of the system is presented in this work. Electrostatics and charged particle tracing simulations were employed to dimension components in the vacuum system and estimate the size of the ion beam spot on the target surface. Stable operation of the neutron generator was possible with accelerating potentials of up to −120 kV and an estimated averaged ion beam current of around 0.5 mA. At these conditions, the neutron yield was estimated to 6 ⋅ 107 s−1 based on a combination of detailed Monte Carlo MCNP6 models and the ambient dose rate reading of an LB6411 neutron probe. The neutron emitting spot size was compared to the ion beam spot size and experimentally determined with an attenuating edge technique to be between 1.7 and 2.6 mm. With these neutron yield and emitting spot size values, the system compares favorably with commercially available neutron generators, and this context is also presented. • Development and testing of a compact D-D fast neutron generator optimized for transmission-based neutron imaging. • Design features include an ECR microwave ion source, an electron suppression electrode, and a rotating beam target. • Electrostatics and charged particle tracing simulations to estimate ion beam distribution on a beam target rod. • Detailed characterization of performance including total neutron output and emitting spot were performed. [ABSTRACT FROM AUTHOR]