Investigating the hard X-ray production via proton spallation on different materials to detect elements.

Various atomic and nuclear methods use hard (high-energy) X-rays to detect elements. The current study aims to investigate the hard X-ray production rate via high-energy proton beam irradiation of various materials. For which, appropriate conditions for producing X-rays were established. The MCNPX code, based on the Monte Carlo method, was used for simulation. Protons with energies up to 1650 MeV were irradiated on various materials such as carbon, lithium, lead, nickel, salt, and soil, where the resulting X-ray spectra were extracted. The production of X-rays in lead was observed to increase 16 times, with the gain reaching 0.18 as the proton energy increases from 100 MeV to 1650 MeV. Comparatively, salt is a good candidate among the lightweight elements to produce X-rays at a low proton energy of 30 MeV with a production gain of 0.03. Therefore, it is suggested to irradiate the NaCl target with 30 MeV proton to produce X-rays in the 0-2 MeV range.

An alternative method for calculation of half-value layers without the knowledge of attenuation coefficient.

Radiation protection is crucial for the safe utilization of ionizing radiation and minimizing the harmful effect upon exposure, hence some standards have been defined by some relevant organizations for the safe uses of radiation. One of the parameters relevant to the calculation of gamma ray shielding is the half-value layer (HVL), which is normally calculated using the knowledge of linear attenuation coefficient (µ). In this research, an attempt has been made to directly calculate HVL without the knowledge of µ via Monte Carlo simulation technique. For this purpose, in the Monte Carlo N-Particle eXtended (MCNPX) code, F1, F5 and Mesh Popul sequences tallies were defined and the optimal structure for the least measurement error was introduced. The MCNPX calculated values showed reasonable agreement with the experimental findings. According to the obtained results, it is suggested that in order to reduce the error of HVL calculations, in exchange for the MCNPX code, the values of the R parameter and the radiation angle of the source should be considered according to the calculations introduced in this plan. Because the results show that by considering the measurement error between 6 and 20%, the code output can be cited in different energy ranges.

Study of alpha spectrometry for detection of radon and progeny using gas micro-strip detector.

In this paper, simulation of a gas micro-strip detector by using the MCNPX code, the feasibility of alpha spectroscopy for radon and its progeny has been investigated. Initially, for the verification of the code, the range of alpha particles released from 222Rn gas in the air has been obtained in the standard condition, which is consistent with the experimental results. Subsequently, the energy loss per unit path length, range of alpha particles and radon progeny was measured, then the relationship between the range, the energy and the air pressure has been achieved. Finally, the simulation results have been compared with the results of the particle range relationship, pressure and energy, and the radon spectroscopy has been performed with the studied detector. The comparison of the spectrum obtained with the simulated micro-strip detector and the experimental results shows that the introduced micro-strip detector, in addition to the ability to measure radon and daughters, also has the ability to extract the spectrum from it.