Study of afterglow in x-ray phosphors for use on fast-framing charge-coupled device detectors
Abstract
There is a need in the x-ray imaging community for phosphors with short persistence (///o less than 0.1 to 0.01% in less than 0.5 ms). Persistence limits a detector's performance by defining the minimum x-ray exposure discernible for a given time after a previous exposure, by ghosting of previous images, and by limiting the dynamic range. We characterize the persistence and relative light output of 25 commercially available and specially synthesized phosphors, five of which are gadolinium oxysulfide (Gd2O2S) with five different activators. The phosphor's 'practical efficiency' is presented for use with either front- or rear-illuminated CCDs. The persistence of these phosphors is characterized as a function of x-ray intensity, exposure time, and, when possible, impurity concentrations. Each phosphor's usefulness for particular x-ray imaging experiments is also discussed.
- Publication:
-
Optical Engineering
- Pub Date:
- November 1997
- DOI:
- 10.1117/1.601530
- Bibcode:
- 1997OptEn..36.3212S