- Title
- Empirical study of the spatial variation of recombination, polarity and polarization effects in ionization chambers
- Creator
- Butler, Duncan J.; Beveridge, Toby; Lehmann, Joerg; Oliver, Chris P.; Bailey, Tracy E.; Stevenson, Andrew W.; Livingstone, Jayde
- Relation
- Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Vol. 914, Issue 11 January 2019, p. 15-24
- Publisher Link
- http://dx.doi.org/10.1016/j.nima.2018.10.095
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2019
- Description
- We present measurements of the spatial response of two ionization chambers obtained by scanning them through a 0.1 mm diameter beam of synchrotron radiation (weighted-average energy 95 keV). The technique was used to investigate the spatial variation of effects associated with recombination, bias voltage and beam polarization on the signal. The chamber types investigated were the PTW model 30013 0.6 cm3 Farmer-type chamber and the Exradin model A5 100 cm3 spherical chamber. Recombination was found to vary according to the local electric field strength inside the chamber and the volume of air presented to the beam. The bias polarity effect was found to be small and relatively uniform across the chamber. Within the accuracy of the measurements, no difference could be determined between response scans with the electric field vector of the incident beam aligned parallel and orthogonal to the chamber axis.
- Subject
- dosimetry; kilovoltage; synchrotron; ionization chamber; high resolution
- Identifier
- http://hdl.handle.net/1959.13/1444186
- Identifier
- uon:42225
- Identifier
- ISSN:0168-9002
- Language
- eng
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