A study of recombination losses in liquid ionization chambers
(English)Manuscript (preprint) (Other academic)
In the present work, recombination losses in liquid ionization chambers are studied by employing theories derived for gas-filled ionization chambers. A new and robust approximate relation for the general collection efficiency is derived, which is theoretically and experimentally investigated alongside existing theory. Ionized liquids can be strongly affected by both initial and general recombination, and these effects have therefore been disassociated by the two-dose-rate method in order to evaluate the soundness of modelling recombination losses in liquids according to theories for gases, where initial recombination is negligible. The results indicate that liquids and gases have very similar general recombination characteristics, where liquids mimic the behaviour expected in gases. However, it is shown that the disassociation of initial and general recombination in the two-dose-rate method is not trivial since initial recombination depends on the spatial variation of the collecting electric field, which in turn is employed to describe the general collection efficiency. The problem of initial recombination in liquids is also shown to be further complicated by a dependence on the radiation quality, as well as the type of liquid employed as the sensitive media.
General recombination, initial recombination, liquid ionization chamber, radiation dosimetry, isooctane, tetramethylsilane
Other Physics Topics Radiology, Nuclear Medicine and Medical Imaging
IdentifiersURN: urn:nbn:se:umu:diva-68941OAI: oai:DiVA.org:umu-68941DiVA: diva2:618905