Abstract:
:Recently, a new family of low-cost x-radiation detectors have been developed, based on semiconducting polymer diodes, which are easy to process, mechanically flexible, relatively inexpensive, and able to cover large areas. To test their potential for radiotherapy applications such as beam monitors or dosimeters, as an alternative to the use of solid-state inorganic detectors, we present the direct detection of 6 MV x-rays from a medical linear accelerator using a thick film, semiconducting polymer detector. The diode was subjected to 4 ms pulses of 6 MV x-rays at a rate of 60 Hz, and produces a linear increase in photocurrent with increasing dose rate (from 16.7 to 66.7 mGy s(-1)). The sensitivity of the diode was found to range from 13 to 20 nC mGy(-1) cm(-3), for operating voltages from -50 to -150 V, respectively. The diode response was found to be stable after exposure to doses up to 15 Gy. Testing beyond this dose range was not carried out. Theoretical calculations show that the addition of heavy metallic nanoparticles to polymer films, even at low volume fractions, increases the x-ray sensitivity of the polymer film/nanoparticle composite so that it exceeds that for silicon over a wide range of x-ray energies. The possibility of detecting x-rays with energies relevant to medical oncology applications opens up the potential for these polymer detectors to be used in detection and imaging applications using medical x-ray beams.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Mills CA,Chan YF,Intaniwet A,Shkunov M,Nisbet A,Keddie JL,Sellin PJdoi
10.1088/0031-9155/58/13/4471subject
Has Abstractpub_date
2013-07-07 00:00:00pages
4471-82issue
13eissn
0031-9155issn
1361-6560journal_volume
58pub_type
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