This paper summarizes the development of a distributed x-ray source with up to 60kW demonstrated instantaneous
power. Component integration and test results are shown for the dispenser cathode electron gun, fast switching controls,
high voltage stand-off insulator, brazed anode, and vacuum system. The current multisource prototype has been
operated for over 100 hours without failure, and additional testing is needed to discover the limiting component.
Example focal spot measurements and x-ray radiographs are included. Lastly, future development opportunities are
We report on the design of a neutron detector using industry standard <sup>3</sup>He tubes to count delayed neutrons during the
interrogation of cargo containers for the presence of Special Nuclear Material (SNM). Simulations of the detector
design were run for delayed neutron spectra for a variety of cargos containing SNM using the Monte Carlo computer
code COG. The simulations identified parameters crucial to optimize the detector design. These choices include
moderating material type and thickness, tube spacing, tube pressure and number of tubes. An experimental prototype
was also constructed based on the simulated design specifications. This paper discusses the parameters that lead up to
the optimized detector design. It also compares the performance of the Monte Carlo simulated design and the
experimental detector when exposed to a <sup>239</sup>Pu-Be source.
Hand-Held RadioIsotope Identification Devices (HHRIID) are defined as a new class of portable neutron/gamma
radiation detectors with specifications presented in the ANSI Standards N42.33 and N42.34. We have proposed a novel
HHRIID design concept which uses a single photosensor to detect light emitted by two optically separated scintillator
materials, one optimized for gamma detection and the other optimized for neutron detection. This work describes the
performance of a modified charge integration discrimination method developed to test the viability of the new design.
The scintillators chosen for the experiment were LYSO and ZnS:Ag/LiF.
The output response characteristics of an X-ray photon counting detector are measured experimentally and
simulated using a Monte Carlo method in order to quantify the loss of statistical information due to pile-up. The
analysis is applied to idealize counting detector models, but is adaptable to realistic event processing that is not
amenable to analytic solution. In particular, the detective quantum efficiency (DQE) is calculated as a function of flux
rate and shown to have an intermediate zero for the paralyzable case at the maximum periodic rate. The progressive
degradation of the spectral response as a function of increasing flux rate is also modeled. Analogous metrics to DQE
are defined in regards to the detector's ability to resolve atomic number and enhance image contrast based on atomic
number differentiation. Analytic solutions are provided for the output and linearized response statistics and these
interpolate well across the Monte Carlo and experimental results.