Optimization of the electric field distribution in a large volume tissue-equivalent proportional counter.

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 Biol

authors

Verma PK,Waker AJ

doi

10.1088/0031-9155/37/10/002

subject

Has Abstract

pub_date

1992-10-01 00:00:00

pages

1837-46

issue

10

eissn

0031-9155

issn

1361-6560

journal_volume

37

pub_type

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