Abstract：
:Noise power spectrum (NPS) and detective quantum efficiency (DQE) for metal-plate/film portal detectors are reported for the Co-60 and Linac 10 MV spectra. The detectors consist of a double-emulsion portal film secured between plates of aluminum, copper, brass, or lead. The NPS was found to be independent of the detector sensitivity demonstrating that the film grain noise dominates over the quantum noise. Although the detector signal increases with density of the backplates, the resultant electron-backscatter increases detector blur, thus decreasing the DQE. The lowest DQEs are therefore produced with the lead backplates, irrespective of the front plates. For a given backplate and for front-plate thicknesses less than the maximum electron range, the DQE increases with density of the front plate.
journal_name
Med Physjournal_title
Medical physicsauthors
Falco T,Fallone BGdoi
10.1118/1.598437subject
Has Abstractpub_date
1998-12-01 00:00:00pages
2463-8issue
12eissn
0094-2405issn
2473-4209journal_volume
25pub_type
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