Reply to 'gamma radiation measurement'
On page 441, Ramli et al make a statement that the Ludlum micro-R meter has an almost flat response to gamma radiation. I think this is unlikely, as the instrument is basically a simple sodium iodide scintillator based ratemeter with a fixed energy threshold. Such instruments generally have a respon...
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| Format: | Article |
| Language: | English |
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Institute of Physics Publishing Ltd.
2006
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| Online Access: | http://eprints.utm.my/9037/ http://eprints.utm.my/9037/1/AhmadTermiziRamli2006_Replyto%27GammaRadiationMeasurement%27.pdf |
| _version_ | 1848891796756627456 |
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| author | Ramli, Ahmad Termizi |
| author_facet | Ramli, Ahmad Termizi |
| author_sort | Ramli, Ahmad Termizi |
| building | UTeM Institutional Repository |
| collection | Online Access |
| description | On page 441, Ramli et al make a statement that the Ludlum micro-R meter has an almost flat response to gamma radiation. I think this is unlikely, as the instrument is basically a simple sodium iodide scintillator based ratemeter with a fixed energy threshold. Such instruments generally have a response which varies considerably over the range of interest for environmental dosimetry. This ranges from the highest significant energy generated, 2.615 MeV from Tl-208, down to the lowest energy which is likely to escape from bulk material as a consequence of Compton scatter, around 60 keV. As an example, the response of a 38 mm × 55 mm sodium iodide detector varies over a range of 10 from Co-60 (1.25 MeV) to 109 keV when used in the gross count mode. The range varies by a factor of 2 between Co-60 and Cs-137 (662 keV), which are reasonably close to K-40 at 1.46 MeV and the 609 keV line from Bi-214, both of which are, or can be, major contributors to environmental gamma dose rates. This is with a much bigger detector than the one employed by the authors. Moving to a smaller detector, such as the 25.4 mm × 19 mm one in the Thermo 41 detector, the energy response varies by a factor of 30 from 87 keV to 1.25 MeV, with a Cs-137/Co-60 ratio also of 2. The detector in the instrument used is likely to have a range of response somewhere between the two. |
| first_indexed | 2025-11-15T21:03:40Z |
| format | Article |
| id | utm-9037 |
| institution | Universiti Teknologi Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T21:03:40Z |
| publishDate | 2006 |
| publisher | Institute of Physics Publishing Ltd. |
| recordtype | eprints |
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| spelling | utm-90372018-11-29T07:34:35Z http://eprints.utm.my/9037/ Reply to 'gamma radiation measurement' Ramli, Ahmad Termizi Q Science (General) On page 441, Ramli et al make a statement that the Ludlum micro-R meter has an almost flat response to gamma radiation. I think this is unlikely, as the instrument is basically a simple sodium iodide scintillator based ratemeter with a fixed energy threshold. Such instruments generally have a response which varies considerably over the range of interest for environmental dosimetry. This ranges from the highest significant energy generated, 2.615 MeV from Tl-208, down to the lowest energy which is likely to escape from bulk material as a consequence of Compton scatter, around 60 keV. As an example, the response of a 38 mm × 55 mm sodium iodide detector varies over a range of 10 from Co-60 (1.25 MeV) to 109 keV when used in the gross count mode. The range varies by a factor of 2 between Co-60 and Cs-137 (662 keV), which are reasonably close to K-40 at 1.46 MeV and the 609 keV line from Bi-214, both of which are, or can be, major contributors to environmental gamma dose rates. This is with a much bigger detector than the one employed by the authors. Moving to a smaller detector, such as the 25.4 mm × 19 mm one in the Thermo 41 detector, the energy response varies by a factor of 30 from 87 keV to 1.25 MeV, with a Cs-137/Co-60 ratio also of 2. The detector in the instrument used is likely to have a range of response somewhere between the two. Institute of Physics Publishing Ltd. 2006 Article PeerReviewed application/pdf en http://eprints.utm.my/9037/1/AhmadTermiziRamli2006_Replyto%27GammaRadiationMeasurement%27.pdf Ramli, Ahmad Termizi (2006) Reply to 'gamma radiation measurement'. Journal of Radiological Protection, 26 (2). pp. 236-237. ISSN 0952-4746 http://dx.doi.org/10.1088/0952-4746/26/2/L01 DOI:10.1088/0952-4746/26/2/L01 |
| spellingShingle | Q Science (General) Ramli, Ahmad Termizi Reply to 'gamma radiation measurement' |
| title | Reply to 'gamma radiation measurement' |
| title_full | Reply to 'gamma radiation measurement' |
| title_fullStr | Reply to 'gamma radiation measurement' |
| title_full_unstemmed | Reply to 'gamma radiation measurement' |
| title_short | Reply to 'gamma radiation measurement' |
| title_sort | reply to 'gamma radiation measurement' |
| topic | Q Science (General) |
| url | http://eprints.utm.my/9037/ http://eprints.utm.my/9037/ http://eprints.utm.my/9037/ http://eprints.utm.my/9037/1/AhmadTermiziRamli2006_Replyto%27GammaRadiationMeasurement%27.pdf |