Ze-Jie Yin

Geant4 used in medical physics and hadrontherapy technique

Abstract This article mainly presents the application of Geant4 package (Geant4.7.0, 2005), developed by CERN (the Center of European Research of Nucleus), in medical physics and a novel technique, namely, hadrontherapy. The distribution of energy deposition in a water model by different radiation beams was also given. The results show that the distributions for proton beams are completely different from those for other radiation beams. Charged particles like protons exhibit little scattering when they penetrate the matter and give the highest energy deposition near the end of their range just before they reach the resting state. These characteristics permit very precise control of the shape of the energy distribution inside the patients body.

Energy deposition of γ-ray in different instances and its influence on energy detection

Abstract In this paper, we simulate γ ray energy deposition for different incident energies with four different models using the tool GEANT4 (Geant4.7.0, 2005) developed by CERN (the Center of European Research of Nucleus). The results we obtained indicate that there are different peak values for different incident energies. That is, we can differentiate the incident energy accurately if the detector can determine the peak value accurately. This is meaningful for the geometrical configuration of the detector to get the most probable distribution (MPD) of energy deposition for different incident energies. According to the simulation, we can insert certain slices with large absorption coefficient to obtain a better MPD of energy deposition which will not alter the shape of the energy deposition.

The development of Campbell integration system applied in high particle flux measurement

Campbell Mode is a method widely used in nuclear signal processing. In this article, we introduce the design of the new system based on the Campbell integration measurement applied in NFM (neutron flux measurement) systems for ITER plasma diagnose. In this article, we introduce a digital particle flux measurement system based on Campbell integration theory. A subsequent series of experiment are conducted to test the digital Campbell system performance, which proves that the Campbell integration system is competent for the plasma diagnose in ITER.

Some characteristics of X-ray imaging for energy region of over 100 keV using plastic scintillation fiber array

Abstract In this work, characteristics of using PSFs (plastic scintillation fibers) coupled with CCD (charge-coupled devices) to build area detectors for high energy X-ray imaging are studied with a Monte Carlo simulation, which cover an energy range of a few hundred keV to about 20 MeV. It was found that the efficiency of PSF in detecting X-ray with energy above a few hundred keV is low. We can use large incident flux to increase the output signal to noise ratio (SNR). The performance can also be improved by coating PSF with X-ray absorption layers and the MTF of the system is presented. By optimizing the absorption layer thickness, the crosstalk of the area detector built with PSF decreases.