Analysis of Size and Location of Irradiation Block of Electron Linear Accelerator to Radiation Output and Absorbed Dose

A research on the analysis of the field size and cerrobend block location effect at the electron beam output of Linear Accelerator for output radiation and absorbed dose. Measuring the output of the electron beam at each block location variations for each field size. Measurements using field size 4x10 cm2 , 5x8 cm2 , 8x15 cm2 , and 10x12 cm2 for variation of block 1 to block 11. Output beam at block 1 and block 7 as the reference output data of the other block. The results showed that the radiation output at 5x8 cm2 field size is greater than the output radiation of 4x10 cm2 field size, as well as in 10x12 cm2 field size produces output radiation that is larger than 8x15 cm2 field size. These results indicate that the radiation field with an A/P greater the yield large radiation output. Extensive irradiation field equal to the value of A/P differently and produce output radiation absorbed dose is different. Radiation output at block radiation with a deviation of ≤ 2% can be recommended in clinical therapy for rectangular irradiation field. The measurement results for each different contexts in which radiation produces radiation output is different, the difference is obtained from the correction factor to determine the patient monitor units received on each layout block radiation. The resulting correction factor of 0.919 to 1.131 for block 2 through block 6 and 0.951 to 1.024 for the block 8 to block 11.