Direct Detection of 6 MV X-rays from a Medical Linear Accelerator using a Semiconducting Polymer Diode
Mills, CA, Chan, Y-F, Intaniwet, A, Nisbet, A, Keddie, JL and Sellin, PJ (2013) Direct Detection of 6 MV X-rays from a Medical Linear Accelerator using a Semiconducting Polymer Diode Physics in Medicine and Biology, 58 (13). pp. 4471-4482.
Mills_et_al_Phys_Med_Biol_FINAL SECOND RESUBMIT.pdf
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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.
|Divisions :||Faculty of Engineering and Physical Sciences > Electronic Engineering > Advanced Technology Institute > Nano-Electronics Centre|
|Date :||14 June 2013|
|Identification Number :||10.1088/0031-9155/58/13/4471|
|Uncontrolled Keywords :||X-ray detectors, Linear accelerators, Dosimetry of X-rays, Organic Semiconductors|
|Additional Information :||Copyright 2013 Institute of Physics. This is the author's accepted manuscript.|
|Depositing User :||Symplectic Elements|
|Date Deposited :||25 Jul 2013 09:26|
|Last Modified :||23 Sep 2013 20:10|
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