Abstract:
:A method of radiation dosimetry is described which is based on the radiation-induced initiation of polymerization of a bulk monomer (e.g. methyl methacrylate) containing a small concentration (about 100 ppm) of a compound which is non-fluorescent but which becomes highly fluorescent when it is incorporated into a growing polymer chain of the bulk monomer. We call the overall process 'radio-fluorogenic co-polymerization' or RFCP for short. The method is illustrated by results on the in situ monitoring of the accumulated dose within the irradiation chamber of a cobalt-60 gamma-ray source using a small plastic capsule containing about 0.2 ml of an RFCP solution. Remote monitoring of the fluorescence is carried out on a timescale of seconds using optical fibres connecting the probe to a 360 nm LED excitation source and a miniature spectrophotometer. The fluorescence is permanent and the intensity is linearly proportional to the accumulated dose from a few tenths of a gray up to hundreds of gray. The sensitivity to dose depends on the polymerizable monomer used and obeys a square root dependence on dose rate over the range studied, 0.27-3.76 Gy min(-1). The polymeric nature of the fluorescent product suggests that the RFCP effect could be used to provide fixed two- or three-dimensional fluorescent images of dose deposition in gel films or phantoms.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Warman JM,de Haas MP,Luthjens LHdoi
10.1088/0031-9155/54/10/015subject
Has Abstractpub_date
2009-05-21 00:00:00pages
3185-200issue
10eissn
0031-9155issn
1361-6560pii
S0031-9155(09)08960-Xjournal_volume
54pub_type
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