DocumentCode :
1996460
Title :
Measurements of the intrinsic rise times of common inorganic scintillators
Author :
Derenzo, S.E. ; Weber, M.J. ; Moses, W.W. ; Dujardin, C.
Author_Institution :
Lawrence Berkeley Lab., CA, USA
Volume :
1
fYear :
1999
fDate :
1999
Firstpage :
152
Abstract :
The intrinsic rise times of a number of common inorganic scintillators are determined using ultrafast measurements of luminescence following pulsed X-ray excitation. A Ti-sapphire mode-locked laser and a light-excited X-ray tube are used to produce X-ray pulses with 60 ps fwhm. Fluorescence photons are detected with a microchannel phototube and the response of the phototube and electronics is 45 ps fwhm. Samples are either powders or thin crystals painted black on five sides to reduce delayed scattered photons. The intrinsic scintillators CeF3, CdWO4, Bi4Ge3 O12, and CsI have rise times ⩽30 ps, indicating that electrons are promptly captured to form the excited states. The activated scintillators CaF2:Eu, ZnO:Ga, and Lu2SiO5:Ce have rise times ⩽40 ps, indicating that the luminescent centers are excited by rapid sequential hole capture- electron capture. The activated scintillators CsI:Tl and YAlO 3:Ce have slower rise times due to processes that delay the formation of excited states. It is shown that for practical scintillation detectors, internal reflections in the crystal can degrade observed rise times by hundreds of ps depending on size, reflector, and index of refraction
Keywords :
X-ray effects; photoluminescence; scintillation; solid scintillation detectors; Bi4Ge3O12; CaF2:Eu; CdWO4; CeF3; CsI; CsI:Tl; Lu2SiO5:Ce; X-ray pulses; YAlO3:Ce; ZnO:Ga; activated scintillators; excited states; inorganic scintillators; internal reflection; intrinsic rise times; luminescence; luminescent centers; pulsed X-ray excitation; refractive index; Delay; Fluorescence; Laser excitation; Laser mode locking; Luminescence; Optical pulses; Photoelectricity; Photonic crystals; Pulse measurements; X-ray lasers;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium, 1999. Conference Record. 1999 IEEE
Conference_Location :
Seattle, WA
ISSN :
1082-3654
Print_ISBN :
0-7803-5696-9
Type :
conf
DOI :
10.1109/NSSMIC.1999.842466
Filename :
842466
Link To Document :
بازگشت