1. Dosimetric shield evaluation with tungsten sheet in 4, 6, and 9MeV electron beams
- Author
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Toru Takakura, Hajime Monzen, Kyoji Higashimura, Shinsuke Yano, Takashi Okada, Junichi Kuwahara, Manabu Nakata, Makoto Sasaki, Takahiro Fujimoto, and Masahiro Hiraoka
- Subjects
Paper ,Materials science ,Surface Properties ,business.industry ,Biophysics ,General Physics and Astronomy ,chemistry.chemical_element ,Electrons ,General Medicine ,Electron ,Tungsten ,Radiation Protection ,Optics ,chemistry ,Ionization ,Electromagnetic shielding ,Cathode ray ,Dosimetry ,Radiology, Nuclear Medicine and imaging ,Radiation protection ,Radiometry ,Nuclear medicine ,business ,Beam (structure) - Abstract
In electron radiotherapy, shielding material is required to attenuate beam and scatter. A newly introduced shielding material, tungsten functional paper (TFP), has been anticipated to become a very useful device that is lead-free, light, flexible, and easily processed, containing very fine tungsten powder at as much as 80% by weight. The purpose of this study was to investigate the dosimetric changes due to TFP shielding for electron beams. TFP (thickness 0-15mm) was placed on water or a water-equivalent phantom. Percentage depth ionization and transmission were measured for 4, 6, and 9MeV electron beams. Off-center ratio was also measured using film dosimetry at depth of dose maximum under similar conditions. Then, beam profiles and transmission with two shielding materials, TFP and lead, were evaluated. Reductions of 95% by using TFP at 0.5cm depth occurred at 4, 9, and 15mm with 4, 6, and 9MeV electron beams, respectively. It is found that the dose tend to increase at the field edge shaped with TFP, which might be influenced by the thickness. TFP has several unique features and is very promising as a useful tool for radiation protection for electron beams, among others.
- Published
- 2014