A microcomputer based hardware, the Time Interval Board, was designed and the software interface control program was developed. The board measures time intervals between consecutive pulses from a discriminator output. The data is stored in on-board 16K x 16 memory. The microcomputer empties and processes the data when the on-board memory is filled. Data collection continues until the preset collection period is finished or a forced end is initiated. During this period, control is passed between the hardware and the microcomputer via the interface circuit. The designed hardware is IBM PC compatible.

The detonation of a radiological dispersal device (RDD) may result in casualties receiving exposure of radioactive materials. Assessments of potentially contaminated personnel are necessary to determine the level of contamination received in order to prioritize and treat individuals. The use of improvised explosive devices (IEDs) and the number of orphan sources in deployed and combat areas such as Iraq, present an opportunity for terrorists to use an RDD against deployed ground forces. There is limited capability in Iraq to assess radiological casualties, as the process of obtaining and analyzing bioassays is time consuming and not readily available in country. Military units are equipped with AN/VDR-2 and AN/PDR-77 radiac detectors which are capable of detecting gamma radiation. Therefore, a study of the use of these radiac sets in assessing internal contamination was conducted. A model of the detector probe was created using the Los Alamos National Laboratory Monte Carlo N-Particle transport code, MCNP Version 5. This model was experimentally validated and used in conjunction with both reference male and reference female computational Medical Internal Radiation Dose (MIRD) phantoms to compute internal dose. The instrument model was evaluated at the following locations, the posterior upper right torso, the anterior upper right torso, the lateral upper left thigh and the anterior of the neck. Nuclides were distributed throughout the phantoms using the Oak Ridge National Laboratory Dose and Risk Calculation (DCAL) software for inhalation pathways. Based on the likelihood for use in RDDs and the capabilities of the instrument, Co-60, Cs-137 and Ir-192 were evaluated.

No description available.

This study presents a comprehensive overview of the significance and results of implementing a data analysis for the calibration of an iodine neutrino detector. Previous neutrino detectors have failed to confirm the standard solar model or settle the question of a massive neutrino. An iodine detector, which was proposed in 1988, is being constructed to hopefully resolve these issues. Before the iodine detector can give conclusive results, it must first be calibrated. Because there is no standard neutrino source, these calibrations must be done indirectly. The method for calibrating the 127-Iodine detector is by using a (p,n) reaction at 0' on an iodine target and a proton beam provided by the Indiana University Cyclotron FacHity (IUCF). When a neutrino is captured by 127-Iodine, the nucleus becomes an excited state of 127-Xenon at an energy of 125 keV. By measuring the Gwnow Teller strength fimction of the transition from the ground state in 127-Iodine to the 125 keV excited state in 127-Xenon, the iodine detector can be suitably calibrated. / Department of Physics and Astronomy

The technical implications are discussed, of the physical principles behind ISIS, a large volume nuclear particle detector. The particular solution adopted in ISIS is described, for the accurate acquisition of data at high rates and under poor signal-to-noise conditions. A computer program has been written to simulate the processing of signals and noise within ISIS. To check the validity of the simulation, its predictions have been compared with the results of experiments using prototype equipment. With the aid of the simulation, the performance of ISIS has been investigated as regards the spatial resolution and the particle-identification capability of the device. An optimum design for the whole ISIS device has been attained, as a compromise between this performance and tolerable systematic effects. In addition, it has been shown that, around the operating point, there is an adequate window within which satisfactory performance is maintained.

Thesis (M.S. in Electrical Engineering)--University of California, Berkeley, Jan. 1962. / "UCRL-10001." Includes bibliographical references (leaf 65).

Thesis (M.S. in Physics)--United States Naval Postgraduate School, California. / "Unclassified Physics." Includes bibliographical references (p. 36). 14

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 142-153).

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

In this work novel solid-state neutron detectors based on Gallium Nitride (GaN) have been produced and characterized. GaN is a radiation hard semiconductor which is commonly used in commercial optoelectronic devices. The important design consideration for producing GaN-based neutron detectors have been examined, and device simulations performed. Scintillators and p-i-n diode-type neutron detectors have been grown by metalorganic chemical vapor deposition (MOCVD) and characterized. GaN was found to be intrinsically neutron sensitive through the Nitrogen-14 (n, p) reaction. Neutron conversion layers which produce secondary ionizing radiation were also produced and evaluated. GaN scintillator response was found to scale highly linearly with nuclear reactor power, indicating that GaN-based detectors are suitable for use in the nuclear power industry. This work is the first demonstration of using GaN for neutron detection. This is a novel application for a mature semiconductor material. The results presented here provide a proof-of-concept for solid-state GaN-based neutron detectors which offer many potential advantages over the current state-of-the-art, including lower cost, lower power operation, and mechanical robustness. At present Helium-3 proportional counters are the preferred technology for neutron detection, however this isotope is extremely rare, and there is a global shortage. Meanwhile demand for neutron detectors from the nuclear power, particle physics, and homeland security sectors requires development of novel neutron detectors which are which are functional, cost-effective, and deployable.