코발트-60 감마선의 전자 오염에 관한 연구

• 영문명: Study on the Reduction of Electron Contamination with A Cobalt-60 Gamma Ray
• 발행기관: 대한방사선종양학회
• 저자명: 김태규(Tae Kyu Kim) 전하정(Ha Chung Chun) 이명자(Myung Za Lee)
• 간행물 정보: 『대한방사선종양학회지』제7권 제2호, 293~297쪽, 전체 5쪽
• 주제분류: 의약학 > 종양학
• 파일형태: PDF
• 발행일자: 1989.12.30

영문 초록

Electron contamination due to the interaction between radiation beam and material was analyzed for the factors such as source-skin distance (SSD), field size, tray characteristics and position of filter, which can affect the surface dose in Cobalt teletherapy. Surface dose in open beam was more influenced by SSD with increasing field size. Relative surface charge (RSC) increased with the use of tray (solid, circular hole, slotted), compared with open beam, which is thought to be due to increased electron contamination of the tray. To reduce the surface dose, 0.4mm thick Lipowitz metal filter was used. Compared with open beam, RSC decreased by 8.8%, 11.3%, 13.3%, 16.6%, 19.3% and 21.7% for the field size of 5×5, 10×10, 15×15, 20×20, 25×25 and 30×30cm², respectively. On the contrary, use of Lipowitz metal filter increased RSC at 60 cm or less SSD. Surface dose was effectively reduced with Lpowitz metal filter placed right below solid tray in Cobalt teletherapy.

키워드

Cobalt-60 gamma ray Electron contamination Relative surface charge