Build-up cap materials for measurement of photon head-scatter factors
(1997) In Physics in Medicine and Biology 42(10). p.1875-1886- Abstract
- The suitability of high-Z materials as build-up caps for head-scatter measurements has been investigated. Build-up caps are often used to enable characterization of fields too small for a mini-phantom. We have studied lead and brass build-up caps with sufficiently large wall thicknesses, as compared to the range of contaminating electrons originating in the accelerator head, and compared them with build-up caps made of ionization chamber equivalent materials, i.e. graphite. The results were also compared with measurements taken using square and cylindrical polystyrene mini-phantoms. Field sizes ranging from 3 cm x 3 cm up to 40 cm x 40 cm were studied for nominal photon energies of 4, 6, 10 and 18 MV. The results show that the use of lead... (More)
- The suitability of high-Z materials as build-up caps for head-scatter measurements has been investigated. Build-up caps are often used to enable characterization of fields too small for a mini-phantom. We have studied lead and brass build-up caps with sufficiently large wall thicknesses, as compared to the range of contaminating electrons originating in the accelerator head, and compared them with build-up caps made of ionization chamber equivalent materials, i.e. graphite. The results were also compared with measurements taken using square and cylindrical polystyrene mini-phantoms. Field sizes ranging from 3 cm x 3 cm up to 40 cm x 40 cm were studied for nominal photon energies of 4, 6, 10 and 18 MV. The results show that the use of lead and brass build-up caps produces normalized head-scatter data slightly different from graphite build-up caps for large fields at high photon energies. At lower energies, however, no significant differences were found. The intercomparison between the two different plastic mini-phantoms and graphite caps showed no differences. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1111512
- author
- Weber, Lars LU ; Nilsson, Per LU and Ahnesjö, Anders
- organization
- publishing date
- 1997
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physics in Medicine and Biology
- volume
- 42
- issue
- 10
- pages
- 1875 - 1886
- publisher
- IOP Publishing
- external identifiers
-
- pmid:9364584
- scopus:0030866208
- ISSN
- 1361-6560
- language
- English
- LU publication?
- yes
- id
- b923a84e-d8d3-4f7f-aa1c-1d823206d313 (old id 1111512)
- date added to LUP
- 2016-04-01 12:12:44
- date last changed
- 2022-01-27 00:27:29
@article{b923a84e-d8d3-4f7f-aa1c-1d823206d313, abstract = {{The suitability of high-Z materials as build-up caps for head-scatter measurements has been investigated. Build-up caps are often used to enable characterization of fields too small for a mini-phantom. We have studied lead and brass build-up caps with sufficiently large wall thicknesses, as compared to the range of contaminating electrons originating in the accelerator head, and compared them with build-up caps made of ionization chamber equivalent materials, i.e. graphite. The results were also compared with measurements taken using square and cylindrical polystyrene mini-phantoms. Field sizes ranging from 3 cm x 3 cm up to 40 cm x 40 cm were studied for nominal photon energies of 4, 6, 10 and 18 MV. The results show that the use of lead and brass build-up caps produces normalized head-scatter data slightly different from graphite build-up caps for large fields at high photon energies. At lower energies, however, no significant differences were found. The intercomparison between the two different plastic mini-phantoms and graphite caps showed no differences.}}, author = {{Weber, Lars and Nilsson, Per and Ahnesjö, Anders}}, issn = {{1361-6560}}, language = {{eng}}, number = {{10}}, pages = {{1875--1886}}, publisher = {{IOP Publishing}}, series = {{Physics in Medicine and Biology}}, title = {{Build-up cap materials for measurement of photon head-scatter factors}}, volume = {{42}}, year = {{1997}}, }