Abstract：
:Gd2O2S phosphor screens between 250 and 1000 mg/cm2 thick were evaluated for use in megavoltage imaging systems. The phosphor layers were placed on brass plates ranging from 1 to 5 mm thick, each with and without an optical back reflector (white paint). Light output and spatial resolution were measured at 6- and 23-MV x-ray energies. Light output was found to increase linearly with phosphor thickness up to 500 mg/cm2, reaching a plateau at 1000 mg/cm2. Spatial resolution [modulation transfer function (MTF)] decreased exponentially with phosphor thickness up to 750 mg/cm2, where a minimum was reached. The variation of MTF with phosphor thickness was found to obey a simple empirical relation.
journal_name
Med Physjournal_title
Medical physicsauthors
Wowk B,Shalev Sdoi
10.1118/1.597209subject
Has Abstractpub_date
1994-08-01 00:00:00pages
1269-76issue
8eissn
0094-2405issn
2473-4209journal_volume
21pub_type
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