ANALYSIS OF RADIATION RESPONSE FUNCTION OF NAI CRYSTAL BY EGSNRC MONTE CARLO SIMULATION

• Main Author: Noija, Melissa
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/74776
• Institution: Institut Teknologi Bandung

This study was conducted to analyze the response of NaI crystal material from the scintillator detector with monte carlo simulation using the user code in the EGSnrc program, detector.mortran, when the NaI crystal material is fired with radiation. Simulations are carried out using a photon radiation beam in the form of a narrow beam with monoenergetic intensity fired at NaI crystals with cuboid geometry that has a large surface area in the infinite X-Y direction and is limited in the z direction which is the thickness of the crystal material. The material response was analyzed through the thickness of the NaI crystal material and the value of the photon energy used. There were 3 variations of incident photon energy (EIN), namely 3 MeV, 4 MeV, and 5 MeV and 3 variations of NaI crystal material thickness (ZBOUND), namely 0.254 cm, 2.54 cm, and 25.4 cm. In addition to variations in photon energy values and crystal material thickness, 3 variations of BIN energy width (BWIDTH) of 0.05 MeV, 0.1 MeV and 0.1 MeV were also carried out and 3 variations of the number of simulated particles (NCASE) of 5 × 10 5, 1 × 10 6 and 1 × 10 7. The 81 simulated data were then analyzed based on the variation of incident photon energy (EIN), variation of NaI crystal material thickness (ZBOUND), variation of energy BIN width (BWIDTH) and variation of the number of simulated particles (NCASE). The results obtained from the simulation are that the greater the photon energy fired at the NaI crystal material, the smaller the number of energy chopping particles stored in the material. The thicker the NaI crystal material, the more the number of energy chopping particles stored in the material if the same amount of photon energy is fired. The BIN energy width (BWIDTH) affects the distribution of the number of chopped particles for each energy level in the energy spectrum. The greater the number of particles simulated, the longer the time required for simulation.