Simulation of gamma radiation interaction of Co-60 with Tungsten, lead, and Bismuth collimator materials using MCNPX

• Main Authors: Effendi, Mukhtar, Sarofina, Durrotus, Wihantoro, Haryadi, Aris
• Format: Conference Proceeding
• Language: English
• Subjects: Absorption; Bismuth; Collimators; Contamination; Gamma rays; Photons; Radiation; Radiation sources; Radiation therapy; Simulation; Spread spectrum; Tungsten
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0211283

The widening of the gamma radiation field in radiotherapy is caused by a scattering known as the umbra. This study simulated the interaction of Co-60 source Gamma radiation with Tungsten, Lead, and Bismuth collimator materials using the MCNPX program. This study aims to determine the spectral characteristics of the scattered gamma rays after interacting with the target material and determine the value of absorption and electron contamination of the target material by simulation. This research was carried out in three stages: in stage I, the radiation source was modeled as a point and assumed to be uniformly distributed in one direction with an energy of 1.17 and 1.33 MeV. Phase II modeled the geometry of Tungsten, Lead, and Bismuth materials. Stage III is determining the HVL value from the simulation until the appropriate thickness is obtained. Then the process of running and processing the simulation data is carried out. A simulation of photon travel is observed when a photon detaches from the source and interacts with the target material. The results were obtained in the form of absorption of gamma rays and electron contamination, as well as the spectrum of radiation scattered by gamma rays. The research results concluded that the bismuth material with Z=83 had a high absorption value, low electron contamination, and a small spread spectrum.