DocumentCode :
1078774
Title :
Radiation Effects on the Performance of CMOS Photodiode Array Detectors and the Role of Gain-Offset Corrections
Author :
Kim, Ho Kyung ; Cho, Min Kook ; Achterkirchen, Thorsten ; Lee, Wonho
Author_Institution :
Mech. Eng. Dept., Pusan Nat. Univ., Busan
Volume :
56
Issue :
3
fYear :
2009
fDate :
6/1/2009 12:00:00 AM
Firstpage :
1179
Lastpage :
1183
Abstract :
We report the observation of performance degradation in a detector consisting of a phosphor screen and a CMOS (complementary metal-oxide-semiconductor) photodiode array under the continuous irradiation of 45-kVp x-rays. The performance was assessed in terms of dark pixel signal, dynamic range, modulation-transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). From the measurement results, it has been observed that the increase of dark pixel signal and the related noise gradually reduces the dynamic range as the cumulative input exposure to the detector increases. Severe degradation in NPS was observed, which gives rise to reduction in DQE as the cumulative input exposure increases. With carefully updated offset and gain correction, however, we can overcome the detrimental effects of increased dark current on NPS and DQE.
Keywords :
X-ray effects; dark conductivity; photodiodes; semiconductor counters; CMOS photodiode array detectors; X-ray irradiation; complementary metal-oxide-semiconductor; dark pixel signal; detective quantum efficiency; gain-offset corrections; modulation-transfer function; noise-power spectrum; phosphor screen; radiation effects; Degradation; Dynamic range; Noise measurement; Phosphors; Photodiodes; Radiation detectors; Radiation effects; Sensor arrays; X-ray detection; X-ray detectors; CMOS detector; CMOS devices; X-ray imaging; detective quantum efficiency; digital radiography; flat-field correction; image evaluation; image sensors; noise-power spectrum; radiation effects;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2009.2014232
Filename :
5075992
Link To Document :
بازگشت