MCNP Monte Carlo Simulations for Compton Scattering Imaging System Development

Project description:

The need to inspect discontinuity in high atomic-number materials objects was pointed out by the industry. We propose a new method to locate discontinuity in metals using a detector system array based on the Compton scattering dependence on electron density. The methodology is planed to be investigated using Monte Carlo simulations for many sizes and types of holes inside the materials. Detection optimization will be carried out for the imaging system. The R&D stage will include software developments for 3-D image processing and a viewer.

Cooperation with outer researchers:

Dr. Ilan Yaar - Negev NRC

Dr. Shlomo Mark - Sami Shamun College.

Multi-Energy Calibration System for Radiation Dosimeters Based on the Compton Effect

Project description:

Multi-Energy Calibration System for Radiation Dosimeters Based on the Compton Effect Dosimeters calibration is one of the most common practices in dosimetry laboratories. Each dosimeter must go through a well determined calibration process, where it has to be exposed to a calibrated radiation source with a certain energy and exposure rate, most likely by using 137Cs or 60Co sources. In this way, the dosimeter can be calibrated in one or two energy measured points, while the rest of the energy range will be achieved by using a calculated factor or a correction function. In this work, a new calibration method for a wide energy range dosimeter response is offered. A single energy 137Cs source combined with a target is used to produce a continuance angular dependent Compton spectrum on the dosimeter face. This study includes target optimization, using MCNP Monte Carlo simulations, in order to maximize the beam intensity on the detector face. The simulations results were validated using a copper target and a CsI(Tl) scintillation detector.

Cooperation with outer researchers:

Dr. Ilan Yaar - Negev NRC

Soft X-rays Monte Carlo Simulations for Micro Spectroscopy using Synchrotron Radiation

Project description:

A. We upgraded the EGS4 recently to include the ability to simulate soft X-Rays below 1 keV (down to 100 eV). Several imaging cases were simulated in order to validate the possibility to detect nano-scale contaminations in solutions. This progress may assist in new micro spectroscopy aspects such as in water poisoning alarming research and developments. The research aims to obtain Phosphorus detection limit in drinking water as a counter-terrorism method. B. We are studying the low-energy photon absorption in the cell nucleolus as part of the low-dose hazard effectiveness mechanism research. The program will be directed to evaluations of secondary particle damage from cosmic radiation exposure.

Monte Carlo Simulations of Auger Electrons Absorption in the DNA

Project description:

Auger electron therapy has been investigated for several element emissions such as Iodine, Indium and Platinum. The high Z-number atoms are administered into the cell nucleus using a complex molecule. After insertion into the cell nucleus, Auger electrons can be emitted by energetic photon irradiations. The Auger electrons emission has discrete spectral lines due to the electron quantum levels transmissions probabilities. In this research we established a geometrical model for the chromatin, and it's content. The DNA is wrapped around histons (proteins), and the Auger electrons are emitted from the atom into the DNA. We simulate the electrons transport in the chromatin using the EGS4 Monte Carlo code. The electrons energies were set to cover all possible energies for any spectra emission from all atoms up to the highest energy of Pt. The dose absorption in the DNA was calculated for each case, in order to formulate dose versus Auger emission per a given atom.

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