Monte-Carlo simulation of the dynamic behavior of a CMOS inverter struck by a heavy ion

In this study, the applicability of Monte Carlo code particle and heavy ion transport code system (PHITS) [Sato et al. (2013, “Particle and Heavy Ion Transport Code System PHITS, Version 2.52,” J. Nucl. Sci. Technol., 50(9), pp. 913–923)] to the equipment design of sampler and detector in the radiation monitoring system was evaluated by comparing calculation results with experimental results obtained by actual measurements of radioactive materials. In modeling a simulation configuration, reproducing the energy distribution of beta-ray emitted from specific nuclide by means of Fermi Function was performed as well as geometric arrangement of the detector in the sampler volume. The reproducing and geometric arrangement proved that the calculation results are in excellent matching with actual experimental results. Moreover, reproducing the Gaussian energy distribution to the radiation energy deposition was performed according to experimental results obtained by the multi-channel analyzer. Through the modeling and the Monte Carlo simulation, key parameters for equipment design were identified and evaluated. Based on the results, it was confirmed that the Monte Carlo simulation is capable of supporting the evaluation of the equipment design.

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Effective dose estimation in cone-beam computed tomography for dental use by Monte-Carlo simulation optimizing calculation numbers using a step-and-shoot method

Dentomaxillofacial Radiology ◽

10.1259/dmfr.20210084 ◽

2021 ◽

pp. 20210084

Author(s):

Yoshihiro Ozaki ◽

Hiroshi Watanabe ◽

Tohru Kurabayashi

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Effective Dose ◽

Heavy Ion ◽

Cone Beam ◽

Dose Estimation ◽

Organ Doses ◽

Shoot Method ◽

Step And Shoot ◽

Effective Doses

Objective: The objective of this study was to perform effective dose estimation in cone-beam CT for dental use (CBCT) using a Monte-Carlo simulation employing a step-and-shoot method as well as to determine the optimal number of steps. Methods: We simulated 3DX Accuitomo FPD8 as a CBCT model and estimated the effective doses of a large and a small field of view (FOV) examination against the virtual Rando phantom using a particle and heavy ion transport code system. We confirmed the results compared to those from a thermo-luminescence dosemeter (TLD) system in a real phantom and investigated how the reduced angle calculations could be accepted. Results: The effective doses of both FOVs estimated with each one degree were almost the same as those estimated from the TLD measurements. Considering the effective doses and the itemized organ doses, simulation with 5° and 10° is acceptable for the large and small FOV, respectively. We tried to compare an effective dose with a large FOV as well as with multiple small FOVs covering the corresponding area and found that the effective dose from six small FOVs was approximately 1.2 times higher than that of the large FOVs. Conclusion: We successfully performed a Monte-Carlo simulation using a step-and-shoot method and estimated the effective dose in CBCT. Our findings indicate that simulation with 5° or 10° is acceptable based on the FOV size, while a small multiple FOV scan is recommended from a radiation protection viewpoint.

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