title: Determination of absorbed dose to water in a  clinical carbon ion beam by means of fluorescent nuclear track detectors, ionization chambers, and  water calorimetry
creator: Osinga-Blättermann, Julia-Maria
subject: ddc-530
subject: 530 Physics
description: Until now, dosimetry of carbon ions with ionization chambers has not reached the same level of accuracy as of high-energy photons. This is mainly caused by the threefold higher uncertainty of the kQ,Q0 -factor of ionization chambers, which is derived by calculations due to a lack of experimental data.  The current thesis comprises two major aims with respect to the dosimetry of carbon ion beams: first, the investigation of the potential of fluorescent nuclear track detectors for fluence-based dosimetry and second, the experimental determination of the kQ,Q0 -factor. The direct comparison of fluence- and ionization-based measurements has shown a significant discrepancy of 4.5 %, which re-opened the discussion on the accuracy of calculated kQ,Q0 -factors.  Therefore, absorbed dose to water measurements by means of water calorimetry have been performed allowing for the direct calibration of ionization chambers and thus for the experimental determination of kQ,Q0. For the first time it could be shown that the experimental determination of kQ,Q0 for carbon ion beams is achievable with a standard measurement uncertainty of 0.8 %. This corresponds to a threefold reduction of the uncertainty compared to calculated values and therefore enables to significantly decrease the overall uncertainty related to ionization-based dosimetry of clinical carbon ion beams.
date: 2017
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/22452/1/Dissertation.pdf
identifier: DOI:10.11588/heidok.00022452
identifier: urn:nbn:de:bsz:16-heidok-224520
identifier:   Osinga-Blättermann, Julia-Maria  (2017) Determination of absorbed dose to water in a clinical carbon ion beam by means of fluorescent nuclear track detectors, ionization chambers, and water calorimetry.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/22452/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng