Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Experimentally determined and Monte Carlo-calculated energy dependence of NaCl pellets read by optically stimulated luminescence for photon beams in the energy range 30 keV to 1.25 MeV

Waldner, Lovisa LU orcid ; Rääf, Christopher LU ; Hinrichsen, Yvonne LU ; Herrnsdorf, Lars LU and Bernhardsson, Christian LU orcid (2020) In Journal of Radiological Protection 40(4). p.1321-1335
Abstract

Ordinary salt, NaCl, has many properties suitable for dosimetry and has been suggested for both retrospective and prospective optically stimulated luminescence (OSL) dosimetry. Lately, the focus has been on NaCl that is compressed into solid pellets, as this improves both its handling and dosimetric properties. In this project, the energy dependence of NaCl pellets produced in-house was investigated for photon energies between 30 and 1.25 MeV. The NaCl pellets were first exposed to free-in-air conditions, and the estimated absorbed dose to the NaCl pellets was compared to the air kerma, K air, at the point of exposure. Second, a backscatter medium of polymethyl methacrylate (PMMA) was added, and NaCl pellets were exposed when positioned... (More)

Ordinary salt, NaCl, has many properties suitable for dosimetry and has been suggested for both retrospective and prospective optically stimulated luminescence (OSL) dosimetry. Lately, the focus has been on NaCl that is compressed into solid pellets, as this improves both its handling and dosimetric properties. In this project, the energy dependence of NaCl pellets produced in-house was investigated for photon energies between 30 and 1.25 MeV. The NaCl pellets were first exposed to free-in-air conditions, and the estimated absorbed dose to the NaCl pellets was compared to the air kerma, K air, at the point of exposure. Second, a backscatter medium of polymethyl methacrylate (PMMA) was added, and NaCl pellets were exposed when positioned on a ISO slab phantom to relate the response in the NaCl to the personal dose equivalent, H p(10). The results show a significant energy dependence for exposure to low-energy photons with a peak over-response compared to K air and H p(10) of up to 18. Comparisons with Monte Carlo simulations show good agreement, even though the simulations cannot account for properties related to the intrinsic luminescence effects of the NaCl pellets or the readout and calibration process. The finite thickness of the NaCl pellet makes it an imperfect Bragg-Grey cavity, which complicates the behaviour of the energy dependence. The results presented here may serve as an important basis for further experimental and theoretical modelling of a build-up layer and filters in efforts to develop a passive personal dosemeter based on NaCl.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
dosimetry, energy dependence, NaCl pellets, OSL
in
Journal of Radiological Protection
volume
40
issue
4
pages
15 pages
publisher
IOP Publishing
external identifiers
  • pmid:33045684
  • scopus:85096308700
ISSN
0952-4746
DOI
10.1088/1361-6498/abc052
language
English
LU publication?
yes
id
08881340-c841-4968-bb9e-012e70412325
date added to LUP
2020-11-30 10:35:18
date last changed
2024-05-30 01:13:32
@article{08881340-c841-4968-bb9e-012e70412325,
  abstract     = {{<p>Ordinary salt, NaCl, has many properties suitable for dosimetry and has been suggested for both retrospective and prospective optically stimulated luminescence (OSL) dosimetry. Lately, the focus has been on NaCl that is compressed into solid pellets, as this improves both its handling and dosimetric properties. In this project, the energy dependence of NaCl pellets produced in-house was investigated for photon energies between 30 and 1.25 MeV. The NaCl pellets were first exposed to free-in-air conditions, and the estimated absorbed dose to the NaCl pellets was compared to the air kerma, K air, at the point of exposure. Second, a backscatter medium of polymethyl methacrylate (PMMA) was added, and NaCl pellets were exposed when positioned on a ISO slab phantom to relate the response in the NaCl to the personal dose equivalent, H p(10). The results show a significant energy dependence for exposure to low-energy photons with a peak over-response compared to K air and H p(10) of up to 18. Comparisons with Monte Carlo simulations show good agreement, even though the simulations cannot account for properties related to the intrinsic luminescence effects of the NaCl pellets or the readout and calibration process. The finite thickness of the NaCl pellet makes it an imperfect Bragg-Grey cavity, which complicates the behaviour of the energy dependence. The results presented here may serve as an important basis for further experimental and theoretical modelling of a build-up layer and filters in efforts to develop a passive personal dosemeter based on NaCl. </p>}},
  author       = {{Waldner, Lovisa and Rääf, Christopher and Hinrichsen, Yvonne and Herrnsdorf, Lars and Bernhardsson, Christian}},
  issn         = {{0952-4746}},
  keywords     = {{dosimetry; energy dependence; NaCl pellets; OSL}},
  language     = {{eng}},
  number       = {{4}},
  pages        = {{1321--1335}},
  publisher    = {{IOP Publishing}},
  series       = {{Journal of Radiological Protection}},
  title        = {{Experimentally determined and Monte Carlo-calculated energy dependence of NaCl pellets read by optically stimulated luminescence for photon beams in the energy range 30 keV to 1.25 MeV}},
  url          = {{http://dx.doi.org/10.1088/1361-6498/abc052}},
  doi          = {{10.1088/1361-6498/abc052}},
  volume       = {{40}},
  year         = {{2020}},
}