Modeling and Analysis of Percentage Depth Dose (PDD) and Dose Profile of X-Ray Beam Produced by Linac Device with Voltage Variation

The Percentage Depth Dose (PDD) and dose profile of X-Ray output from a LINAC therapy device have been modeled analyzed. research was conducted by simulation method through the use Particle Heavy Ion Transport code System (PHITS) program. in this work refers to Siemens Primus device, which is operated at 6 MV, 10 MV 18 voltages. Determination PDD carried depth 0-30 cm 0-20 water phantom, placed 100 source, exposed radiation field area 10×10 2 . Results modeling agrees with actual X-ray apparatus has produced Bremsstrahlung X-ray. It found analysis curve that maximum doses are 1.5 cm, 2.5 3.4 cm. value build up factor for each voltage reference. Additionally,  results suggest good degree uniformity. flatness occurs 20 percentage 1.6 %, 1.9 % 1.2 %. values all less than 2%. shows ≤ deviation reference value, below tolerance range required measurement.