Document Detail


A synthetic diamond probe for low-energy X-ray dose measurements.
MedLine Citation:
PMID:  17292614     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The desirable physical properties of diamond have made the mineral a choice material in radiation measurements. Diamond detectors are currently used extensively in high-energy physics. Their use for low-energy beams such as, for example, in mammography X-ray beams however, has not been fully investigated. This paper describes a diamond probe which has been constructed for the evaluation, as the radiation sensing material, of polycrystalline synthetic diamonds produced by chemical vapour deposition (CVD). The specimens were fabricated in wafer form and so the exposure orientation geometry of the diamond wafers, to give optimum absorption of the incident X-ray beam, was also investigated both experimentally and theoretically. The samples were characterized to obtain information regarding the elemental impurity levels, especially nitrogen, and consequently to establish the material quality. Nitrogen impurities and concentration levels in the diamond lattice have been shown to have a profound effect on the radiation detection properties of diamond. The probe described has the diamond surfaces metallized with titanium, platinum and gold to provide ohmic contacts. The probe was connected independently to both Wellhöfer Dosimetrie (model CU 500) and PTW Unidos E commercial electrometers. In all of the measurements, the incident radiation beam was normal to the edge of the diamond wafer to optimize absorption of the X-ray beam after establishing that this orientation was the optimum geometry. The results of the study are presented in both tabular and graphical forms.
Authors:
M Assiamah; T L Nam; R J Keddy
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2007-02-09
Journal Detail:
Title:  Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine     Volume:  65     ISSN:  0969-8043     ISO Abbreviation:  Appl Radiat Isot     Publication Date:  2007 May 
Date Detail:
Created Date:  2007-03-13     Completed Date:  2007-10-29     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9306253     Medline TA:  Appl Radiat Isot     Country:  England    
Other Details:
Languages:  eng     Pagination:  545-52     Citation Subset:  IM    
Affiliation:
Health Physics Unit and FRD/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa.
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MeSH Terms
Descriptor/Qualifier:
Diamond / chemistry*
Gold / chemistry
Nitrogen / chemistry*
Platinum / chemistry
Radiometry
Titanium / chemistry
X-Rays
Chemical
Reg. No./Substance:
7440-06-4/Platinum; 7440-32-6/Titanium; 7440-57-5/Gold; 7727-37-9/Nitrogen; 7782-40-3/Diamond

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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