JOPSS - Search Results

Journal Articles

Use of GAF-film and PC-scanner for easy high-resolution measurement of ion beam fluence distribution

Agematsu, Takashi; Hanaya, Hiroaki

JAEA-Review 2005-001, TIARA Annual Report 2004, p.355 - 357, 2006/01

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2005-001-p0001-p0126.pdf

We examined a combination of Gaf-chromic film dosimeter HD-810 and an image scanner for a personal computer as two-dimensional densitometer which is cheap, easy to use and allows speedy measurement with high spatial resolution. Linearity of dose response was mesured with RGB component up to 500Gy. The cause of low uniformity in ion beam fluense distribution at the JAERI AVF cyclotron raster beam scanning system was clarified by this method, which was a very sharp concentration of fluence in a beam spot.

Journal Articles

Development of PVB film for low-dose dosimetry in radiation processing

Solomon, H. M.*; Kojima, Takuji

Nucleus, 33, p.16 - 20, 2005/00

Low-dose dosimeters were developed based on the mixture films of polyvinyl butyral (PVB) and the acid-sensitive dye leucomalachite green (LMG). Chloral hydrate (RX) was added to the mixture for enhancement of the radiation sensitivity of the film dosimeters. Different film dosimeter materials were prepared using 9.07 10 $^{-5}$ mole LMG per one gram PVB with various RX:LMG molar concentration ratio. The dosimeter response, which is expressed in terms of change in absorbance at 628 nm per unit thickness, increased linearly with dose and RX concentration. The PVB-LMG dosimeter system, in which the ratio of RX concentration to that of LMG is higher than 10, show measurable dose range of 1-100 Gy for $^{60}$ Co -rays.

Journal Articles

Dyed Polyvinyl Chloride films for use as high-dose routine dosimeters in radiation processing

Mai, H. H.*; Duong, N. D.*; Kojima, Takuji

Radiation Physics and Chemistry, 69(5), p.439 - 444, 2004/04

https://doi.org/10.1016/j.radphyschem.2003.08.006

Times Cited Count：21 Percentile：77.76(Chemistry, Physical)

Characteristics of the polyvinyl chloride films containing 0.11wt% of malachite green oxalate or 6GX-setoglausine with 100m in thickness were studied for use as routine dosimeters in radiation processing. These films show basically color bleaching under $^{60}$ Co -ray irradiation in a dose range of 5 to 50 kGy. The sensitivity of the dosimeters and the linearity of dose response curves are improved by adding 2.5% of chloral hydrate [CClCH(OH)] and 0.15% hydroquinone [HOCHOH]. These additions extent the minimum dose limit to 1 kGy covering dosimetric quality assurance in radiation processing of food and healthcare products. The dose responses of both films at irradiation temperatures of 20-35 $^{circ}$ C are constant relative to those at 25 $^{circ}$ C, and the irradiation temperature coefficients for 35-55 $^{circ}$ C were estimated to be (0.43 0.01)%/ $^{circ}$ C. The dosimeter characteristics are stable within 1% at 25 $^{circ}$ C before and 60 days after irradiation.

Journal Articles

3-45MeV/u ion beam dosimetry using thin film dosimeters

Kojima, Takuji; Sunaga, Hiromi; Takizawa, Haruki*; Hanaya, Hiroaki; Tachibana, Hiroyuki*

Radiation Physics and Chemistry, 68(6), p.975 - 980, 2003/12

https://doi.org/10.1016/j.radphyschem.2003.02.001

Times Cited Count：2 Percentile：18.9(Chemistry, Physical)

Four kinds of film dosimeters well-characterized for low LET radiations were applied to 3-45 MeV/u ions. The dose responses relative to those for low LET radiations are almost one up to about 10 MeV/(mg/cm $^{2}$ ) and gradually become smaller with increase of the stopping power. Overall uncertainty in ion beam dosimetry using these characterized dosimeters is better than 5%(1) including uncertainty in fluence measurement(2%). Lateral and depth dose profile measurements were achievable using characterized Gafchromic dosimeters with the spatial resolution of better than 1 and 10 m, respectively.

Journal Articles

Dosimetry for a few hundred keV electron beams

Kojima, Takuji; Hakoda, Teruyuki; Sunaga, Hiromi; Takizawa, Haruki; Hanaya, Hiroaki

Proceedings of 9th International Conference on Radiation Curing (RadTech Asia '03) (CD-ROM), 4 Pages, 2003/00

Dosimetry study for 300 keV electron beams was performed using Gafchromic film dosimeters having 8-m thick radiation-sensitive layer for dose rate measurement, a prototype total-absorption aluminum calorimeter for energy fluence measurement and semi-empirical calculation using EDMULT code for depth-dose distribution estimation. The three preliminary results are compared concerning to dose rate distribution and energy fluence as a function of depth in air. Influences in dosimetry for 300 keV electrons are discussed based on these results.

Journal Articles

Dosimetry for 3-45 MeV/u ion beams using thin film dosimeters

Kojima, Takuji; Sunaga, Hiromi; Takizawa, Haruki; Hanaya, Hiroaki; Tachibana, Hiroyuki*

JAERI-Review 2002-035, TIARA Annual Report 2001, p.123 - 124, 2002/11

Thin film dosimeters of about 10-200 mm in thickness, which were well -characterized for $^{60}$ Co -rays or 2-MeV electrons, have been applied to dosimetry for ion beams. For development of dosimetry covering the dose range of 0.005 to 200 kGy with high precision within 5%, the linear energy transfer (LET) characteristics of thin films were studied involving development of precise fluence measurement. Dose mapping technique was also developed achieving high spatial resolution values of about 1m and 10m for lateral and depth directions respectively. The outline of the recent development is summarized in this paper.