CCRI supplementary comparison of standards for absorbed dose to water in 60Co gamma radiation at radiation processing dose levels

Burns, D T; Allisy-Roberts, P J; Desrosiers, Marc F.; Nagy, Vitaly; Sharpe, Peter; Laitano, R.F.; Mehta, K.; Schneider, M.K.H.; Zhang, Y.L.

doi:10.1016/j.radphyschem.2006.02.003

Cited by 5 publications

(6 citation statements)

References 10 publications

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“…These laboratories should perform internal system checks that use the experimental design employed in the present work, and follow that with comparisons to verify their rates. Considering that the previous international high-dose dosimetry comparison [ 13 ] did not take this effect into account, it is recommended that for follow-up NMI comparisons the calibration schemes of the participants should be examined prior to starting.…”

Section: Discussionmentioning

confidence: 99%

“…Because it does not offer a high-dose service, the BIPM took part at a single dose level (1 kGy) to provide a direct link to the international reference for absorbed dose to water in 60 Co beams. The comparison was recently published [ 13 ] and found that there was a general level of agreement among the institutes at three dose levels: 5 kGy, 15 kGy, and 30 kGy. The agreement was well within the expanded uncertainty for each institute.…”

Section: The Alanine Dosimeter Dose/dose-rate Effectmentioning

confidence: 91%

“…Concurrent to the Vertical Beam irradiation, alanine dosimeters are irradiated to the same absorbed dose (described in [ 13 ]) in the absolute center of the isodose region of the Pool-source gamma field. This comparison may be repeated as necessary to achieve an acceptable precision of 0.5 %.…”

Section: Calibration Of Nist Gamma Sourcesmentioning

confidence: 99%

“…Dosimeters from each facility are exchanged, measured, and the results compared. Participation in other NMI or multi-NMI international comparisons occurs as appropriate [ 13 ].…”

Section: Calibration Of Nist Gamma Sourcesmentioning

confidence: 99%

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An absorbed-dose/dose-rate dependence for the alanine-EPR dosimetry system and its implications in high-dose ionizing radiation metrology

Mf¹,

Jm²,

Sl³

2008

J. Res. Natl. Inst. Stand. Technol.

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NIST developed the alanine dosimetry system in the early 1990s to replace radiochromic dye film dosimeters. Later in the decade the alanine system was firmly established as a transfer service for high-dose radiation dosimetry and an integral part of the internal calibration scheme supporting these services. Over the course of the last decade, routine monitoring of the system revealed a small but significant observation that, after examination, led to the characterization of a previously unknown absorbed-dose-dependent, dose-rate effect for the alanine system. Though the potential impact of this effect is anticipated to be extremely limited for NIST’s customer-based transfer dosimetry service, much greater implications may be realized for international measurement comparisons between National Measurement Institutes.

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Section: Discussionmentioning

confidence: 99%

Section: The Alanine Dosimeter Dose/dose-rate Effectmentioning

confidence: 91%

Section: Calibration Of Nist Gamma Sourcesmentioning

confidence: 99%

“…Dosimeters from each facility are exchanged, measured, and the results compared. Participation in other NMI or multi-NMI international comparisons occurs as appropriate [ 13 ].…”

Section: Calibration Of Nist Gamma Sourcesmentioning

confidence: 99%

See 2 more Smart Citations

An absorbed-dose/dose-rate dependence for the alanine-EPR dosimetry system and its implications in high-dose ionizing radiation metrology

Mf¹,

Jm²,

Sl³

2008

J. Res. Natl. Inst. Stand. Technol.

View full text Add to dashboard Cite

show abstract

“…The dosimetry system is based on irradiated crystalline alanine measured by electron paramagnetic resonance (EPR) spectrometry. Advancements over the past two decades have enabled the alanine-EPR system to become a world-class transfer reference system that is the centerpiece of high-dose dosimetry services for National Metrology Institutes (NMI) [ 2 ]. Moreover, the high quality of the dosimeter measurements, its relative low sensitivity to environmental influences and handling ease over dye-based systems have hastened the implementation of the alanine dosimetry system for routine use in industrial process dosimetry.…”

Section: Introductionmentioning

confidence: 99%

Optical Passive Sensor Calibration for Satellite Remote Sensing and the Legacy of NOAA and NIST Cooperation

Desrosiers¹

2014

J. RES. NATL. INST. STAN.

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Post-irradiation stability of high-dose dosimeters has traditionally been an important measurement influence quantity. Though the exceptional stability of the alanine dosimeter response with time has rendered this factor a non-issue for routine work, the archival quality of the alanine dosimeter has not been characterized. Here the alanine pellet dosimeter response is measured up to seven years post-irradiation for a range of absorbed doses. This long-term study is accompanied by an examination of the environmental influence quantities (e.g., ambient light) on the relatively short-term (3–4 month) stability of both pellet and film commercial dosimeters. Both dosimeter types demonstrated exceptional stability in the short term and proved to be relatively insensitive to common influence quantities. The long-term data revealed a complex dose-dependent response trend.

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On the perturbation effect and LET dependence of beam quality correction factors in carbon ion beams

et al. 2022

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Background: In a recent study, we reported beam quality correction factors, f Q , in carbon ion beams using Monte Carlo (MC) methods for a cylindrical and a parallel-plate ionization chamber (IC). A non-negligible perturbation effect was observed; however, the magnitude of the perturbation correction due to the specific IC subcomponents was not included. Furthermore, the stopping power data presented in the International Commission on Radiation Units and Measurements (ICRU) report 73 were used, whereas the latest stopping power data have been reported in the ICRU report 90. Purpose: The aim of this study was to extend our previous work by computing f Q correction factors using the ICRU 90 stopping power data and by reporting ICspecific perturbation correction factors.Possible energy or linear energy transfer (LET) dependence of the f Q correction factor was investigated by simulating both pristine beams and spread-out Bragg peaks (SOBPs). Methods: The TOol for PArticle Simulation (TOPAS)/GEANT4 MC code was used in this study. A 30 × 30 × 50 cm 3 water phantom was simulated with a uniform 10 × 10 cm 2 parallel beam incident on the surface. A Farmer-type cylindrical IC (Exradin A12) and two parallel-plate ICs (Exradin P11 and A11) were simulated in TOPAS using the manufacturer-provided geometrical drawings. The f Q correction factor was calculated in pristine carbon ion beams in the 150-450 MeV/u energy range at 2 cm depth and in the middle of the flat region of four SOBPs. The k Q correction factor was calculated by simulating the f Qo correction factor in a 60 Co beam at 5 cm depth. The perturbation correction factors due to the presence of the individual IC subcomponents, such as the displacement effect in the air cavity, collecting electrode, chamber wall, and chamber stem, were calculated at 2 cm depth for monoenergetic beams only. Additionally, the mean dose-averaged and track-averaged LET was calculated at the depths at which the f Q was calculated. Results: The ICRU 90 f Q correction factors were reported. The p dis correction factor was found to be significant for the cylindrical IC with magnitudes up to 1.70%. The individual perturbation corrections for the parallel-plate ICs were <1.0% except for the A11 p cel correction at the lowest energy. The f Q correction for the P11 IC exhibited an energy dependence of >1.00% and displayed differences up to 0.87% between pristine beams and SOBPs. Conversely, the f Q for A11 and A12 displayed a minimal energy dependence of <0.50%. The energy dependence was found to manifest in the LET dependence for the P11 IC. A statistically significant LET dependence was found only for the P11 IC in pristine beams only with a magnitude of <1.10%.

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CCRI supplementary comparison of standards for absorbed dose to water in 60Co gamma radiation at radiation processing dose levels

Cited by 5 publications

References 10 publications

An absorbed-dose/dose-rate dependence for the alanine-EPR dosimetry system and its implications in high-dose ionizing radiation metrology

An absorbed-dose/dose-rate dependence for the alanine-EPR dosimetry system and its implications in high-dose ionizing radiation metrology

Optical Passive Sensor Calibration for Satellite Remote Sensing and the Legacy of NOAA and NIST Cooperation

On the perturbation effect and LET dependence of beam quality correction factors in carbon ion beams

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