Abstract:
:Large volume tissue-equivalent proportional counters are of interest in radiation protection metrology, as the sensitivity in terms of counts per unit absorbed dose in these devices increases as the square of the counter diameter. Conventional solutions to the problem of maintaining a uniform electric field within a counter result in sensitive volume to total volume ratios which are unacceptably low when counter dimensions of the order of 15 cm diameter are considered and when overall compactness is an important design criterion. This work describes the design and optimization of an arrangement of field discs set at different potentials which enable sensitive volume to total volume ratios to approach unity. The method has been used to construct a 12.7 cm diameter right-cylindrical tissue-equivalent proportional counter in which the sensitive volume accounts for over 95% of the total device volume and the gas gain uniformity is maintained to within 3% along the entire length of the anode wire.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Verma PK,Waker AJdoi
10.1088/0031-9155/37/10/002subject
Has Abstractpub_date
1992-10-01 00:00:00pages
1837-46issue
10eissn
0031-9155issn
1361-6560journal_volume
37pub_type
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