{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/2801"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/2801","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"Characterization of a 6 MV photon beam in terms of primary and scattered dose components","abstract":"The purpose of this work was to partition the 6 MV photon beam of a Philips SL75-5 linear accelerator into primary and scattered dose components in water. The two quantities that are necessary to define the primary beam component are a reference dose DR and a primary linear attenuation coefficient μ 0. DR describes the magnitude of the primary dose as a fraction of the total dose in a reference field at a reference depth, while μ 0 describes how the primary dose changes with depth in a medium. The scattered component is the difference between the primary and total dose. μ 0 for the beam in water was determined in four different ways, namely through the extrapolation of measured TMRs to zero field size, through linear attenuation measurements, through the fit of a convolution model to CAPDD data and through a method involving a central axis attenuator. The primary dose component was determined in two ways, namely by the extrapolation of the phantom scatter correction factor to zero field size and also by the central axis attenuator method. μ 0 varied from 0.0445 cm-1 to 0.0469 cm-1 with an average of 0.0455 +- 0.0012 cm-1. DR for a 10 cm x 10 cm field at the depth of maximum dose was found to vary between 0.933 Gy/ 100 MU and 0.935 Gy/ 100 MU, with an average of 0.934 Gy/ 100 MU. These values agree very well with values published in the literature. It has thus been shown that the 6 MV photon beam is separable into primary and scattered dose components.","abstract_html":"The purpose of this work was to partition the 6 MV photon beam of a Philips SL75-5 linear accelerator into primary and scattered dose components in water. The two quantities that are necessary to define the primary beam component are a reference dose DR and a primary linear attenuation coefficient μ 0. DR describes the magnitude of the primary dose as a fraction of the total dose in a reference field at a reference depth, while μ 0 describes how the primary dose changes with depth in a medium. The scattered component is the difference between the primary and total dose. μ 0 for the beam in water was determined in four different ways, namely through the extrapolation of measured TMRs to zero field size, through linear attenuation measurements, through the fit of a convolution model to CAPDD data and through a method involving a central axis attenuator. The primary dose component was determined in two ways, namely by the extrapolation of the phantom scatter correction factor to zero field size and also by the central axis attenuator method. μ 0 varied from 0.0445 cm-1 to 0.0469 cm-1 with an average of 0.0455 +- 0.0012 cm-1. DR for a 10 cm x 10 cm field at the depth of maximum dose was found to vary between 0.933 Gy/ 100 MU and 0.935 Gy/ 100 MU, with an average of 0.934 Gy/ 100 MU. These values agree very well with values published in the literature. It has thus been shown that the 6 MV photon beam is separable into primary and scattered dose components.","abstract_has_math":false,"creators":["Trauernicht, Christoph Jan"],"institution":"Division of Medical Physics","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Hering, E R","Nieto-Camero, Jaime"],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009","date_published":"2009","updated_at":"2026-07-22T22:23:05Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/2801","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Hering, E R","Nieto-Camero, Jaime"]},{"key":"dc:creator","label":"Author","values":["Trauernicht, Christoph Jan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-07-28T11:10:08Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-07-28T11:10:08Z"]},{"key":"dc:date.issued","label":"Date","values":["2009"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Division of Medical Physics"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/2801"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The purpose of this work was to partition the 6 MV photon beam of a Philips SL75-5 linear accelerator into primary and scattered dose components in water. The two quantities that are necessary to define the primary beam component are a reference dose DR and a primary linear attenuation coefficient μ 0. DR describes the magnitude of the primary dose as a fraction of the total dose in a reference field at a reference depth, while μ 0 describes how the primary dose changes with depth in a medium. The scattered component is the difference between the primary and total dose. μ 0 for the beam in water was determined in four different ways, namely through the extrapolation of measured TMRs to zero field size, through linear attenuation measurements, through the fit of a convolution model to CAPDD data and through a method involving a central axis attenuator. The primary dose component was determined in two ways, namely by the extrapolation of the phantom scatter correction factor to zero field size and also by the central axis attenuator method. μ 0 varied from 0.0445 cm-1 to 0.0469 cm-1 with an average of 0.0455 +- 0.0012 cm-1. DR for a 10 cm x 10 cm field at the depth of maximum dose was found to vary between 0.933 Gy/ 100 MU and 0.935 Gy/ 100 MU, with an average of 0.934 Gy/ 100 MU. These values agree very well with values published in the literature. It has thus been shown that the 6 MV photon beam is separable into primary and scattered dose components."]},{"key":"dc:title","label":"Title","values":["Characterization of a 6 MV photon beam in terms of primary and scattered dose components"]}]}],"canonical_facts":{"dc:contributor.advisor":["Hering, E R","Nieto-Camero, Jaime"],"dc:creator":["Trauernicht, Christoph Jan"],"dc:date.accessioned":["2014-07-28T11:10:08Z"],"dc:date.available":["2014-07-28T11:10:08Z"],"dc:date.issued":["2009"],"dc:description.abstract":["The purpose of this work was to partition the 6 MV photon beam of a Philips SL75-5 linear accelerator into primary and scattered dose components in water. The two quantities that are necessary to define the primary beam component are a reference dose DR and a primary linear attenuation coefficient μ 0. DR describes the magnitude of the primary dose as a fraction of the total dose in a reference field at a reference depth, while μ 0 describes how the primary dose changes with depth in a medium. The scattered component is the difference between the primary and total dose. μ 0 for the beam in water was determined in four different ways, namely through the extrapolation of measured TMRs to zero field size, through linear attenuation measurements, through the fit of a convolution model to CAPDD data and through a method involving a central axis attenuator. The primary dose component was determined in two ways, namely by the extrapolation of the phantom scatter correction factor to zero field size and also by the central axis attenuator method. μ 0 varied from 0.0445 cm-1 to 0.0469 cm-1 with an average of 0.0455 +- 0.0012 cm-1. DR for a 10 cm x 10 cm field at the depth of maximum dose was found to vary between 0.933 Gy/ 100 MU and 0.935 Gy/ 100 MU, with an average of 0.934 Gy/ 100 MU. These values agree very well with values published in the literature. It has thus been shown that the 6 MV photon beam is separable into primary and scattered dose components."],"dc:identifier.uri":["http://hdl.handle.net/11427/2801"],"dc:language.iso":["eng"],"dc:publisher.department":["Division of Medical Physics"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["Characterization of a 6 MV photon beam in terms of primary and scattered dose components"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-22T22:23:05Z"}