Contribution of Cerenkov radiation in high-energy x-ray and electron beam film dosimetry using water-substitute phantoms.
The contribution of Cerenkov radiation in high-energy film dosimetry was investigated using commercially available water-substitute phantoms. Doses were evaluated using six phantoms: RMI-451, Mix-DP, WE-211, WE-Black, PMMA and PMMA-Black. The contribution of Cerenkov radiation was determined from the shielded and unshielded evaluation doses when a bare film was inserted into the phantom in a dark room and irradiated. For both x-ray and electron beams, Cerenkov radiation produced a phantom-dependent increase in the unshielded dose when compared with the shielded dose. We also found that the darker the phantom, the smaller the contribution of Cerenkov radiation. These results suggest that for film dosimetry using bare film, the accuracy of dose evaluation may be improved by using phantoms with high opacity.
Fujisaki
Tatsuya
T
Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami, Ibaraki, Japan.
Saitoh
Hidetoshi
H
Hiraoka
Takeshi
T
Kuwabara
Akio
A
Abe
Shinji
S
Inada
Tetsuo
T
D016477:Artifacts; D004583:Electrons; D005373:Film Dosimetry / Q000295:instrumentation* / Q000379:methods*; D019047:Phantoms, Imaging / Q000592:standards; D011786:Quality Control; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D014867:Water; D014965:X-Rays
D014867:Water