Wedge filter for fast neutron beam from NIRS cyclotron
Creators
- 1. National Inst. of Radiological Sciences, Chiba (Japan)
Description
The fast neutron beam from NIRS cyclotron has been in use for the clinical trial of radiotherapy since November 1975. The beam is produced by bombarding a thick beryllium target with 30 MeV deuterons. The polyethylene wedge filter is mounted on the exit of collimator at 140 cm from the target. Wedge filters designed based on the dose gradient method for SSD 190 cm and 6 cm depth were the angle of 260, 400 and 500 for the isodose curves of 300, 450 and 550, respectively. The total dose distribution in tissue equivalent (TE) phantom for neutron beam was obtained by an air-filled cylindrical ionization chamber with TE plastic wall. The resultant dose distributions were satisfactory for practical use but isodose curves were slightly roundish, compared with those for cobalt-60 gamma rays. (author)
Additional details
Publishing Information
- Journal Title
- Nippon Igaku Hoshasen Gakkai Zasshi
- Journal Volume
- 43
- Journal Issue
- 5
- Series
- Nippon Igaku Hoshasen Gakkai Zasshi.
- Journal Page Range
- 691-699
- ISSN
- 0048-0428
INIS
- Country of Publication
- Japan
- Country of Input or Organization
- Japan
- INIS RN
- 15053119
- Subject category
- S43: PARTICLE ACCELERATORS;
- Descriptors DEI
- ANGULAR CORRELATION; DEPTH DOSE DISTRIBUTIONS; FAST NEUTRONS; FILTERS; ISODOSE CURVES; NEUTRON THERAPY; NIRS CYCLOTRON; PHANTOMS; RADIATION DOSES
- Descriptors DEC
- ACCELERATORS; BARYONS; CORRELATIONS; CYCLIC ACCELERATORS; CYCLOTRONS; DISTRIBUTION; ELEMENTARY PARTICLES; FERMIONS; HADRONS; ISOCHRONOUS CYCLOTRONS; MEDICINE; MOCKUP; NEUTRONS; NUCLEONS; RADIATION DOSE DISTRIBUTIONS; RADIOTHERAPY; SPATIAL DISTRIBUTION; SPATIAL DOSE DISTRIBUTIONS; STRUCTURAL MODELS; THERAPY