Automated construction of detector models for efficiency interpolation in gamma-ray spectrometry.
A method was developed for automated construction of detector models in gamma-ray spectrometry, which can be used in Monte Carlo calculations of efficiency calibration curves. Full-energy peak efficiencies were first measured for different gamma-ray energies and for a given sample-detector arrangement and then calculated by the Monte Carlo method. For these calculations a detector model was employed along with a computer algorithm, which seeks agreement between the experimental efficiencies and the calculated ones by automatically determining the parameters of the model. The resulting agreement of the calculated data with the experimental one was within the relative uncertainty of the latter (3-4%) and the parameters of the detector models obtained were close to the values specified by the manufacturers. The detector models thus constructed can then be used for interpolation of calibration curves.
Benchmark study of TRIPOLI-4 through experiment and MCNP codes
Reliability on simulation results is essential in nuclear physics. Although MCNP5 and MCNPX are the world widely used 3D Monte Carlo radiation transport codes, alternative Monte Carlo simulation tools exist to simulate neutral and charged particles' interactions with matter. Therefore, benchmark are required in order to validate these simulation codes. For instance, TRIPOLI-4.7, developed at the French Alternative Energies and Atomic Energy Commission for neutron and photon transport, now also provides the user with a full feature electron-photon electromagnetic shower. Whereas the reliability of TRIPOLI-4.7 for neutron and photon transport has been validated yet, the new development regarding electron-photon matter interaction needs additional validation benchmarks. We will thus demonstrate how accurately TRIPOLI-4's “deposited spectrum” tally can simulate gamma spectrometry problems, compared to MCNP's “F8” tally. The experimental setup is based on an HPGe detector measuring the decay spectrum of an 152Eu source. These results are then compared with those given by MCNPX 2.6d and TRIPOLI-4 codes. This paper deals with both the experimental aspect and simulation. We will demonstrate that TRIPOLI-4 is a potential alternative to both MCNPX and MCNP5 for gamma-electron interaction simulation.
International EMS systems: New South Wales, Australia.
Australia has an area of 7,692,024 km 2 and a population of 19,169,083. The state of New South Wales (NSW) has an area of 801,428 square kilometres and a population of 6,663,700 (June 2002). It contributes 10% of the land area of Australia and 34% of the population. The length of the coastline is 2007 km with an east-west distance of 1450 km (Fig. 1). Approximately 90% of the NSW population resides within 100 km of the coast. The population density is greatest in the Greater Metropolitan Region around Sydney, an area of 1580 square km, population of 4,154,722. Only 0.6% live in regions classified as remote or very remote (based upon distance to regional townships). The climate is generally mild, although temperature extremes range from � /20 8C (Charlotte’s Pass) to 50 8C (far Western NSW). The highest point is 2228 m at Mt. Kosciuszko. However, most of NSW is below 500 m in altitude.