DocumentCode :
3606207
Title :
Picosecond Time Resolved Studies of Photon Transport Inside Scintillators
Author :
ter Weele, David N. ; Schaart, Dennis R. ; Dorenbos, Pieter
Author_Institution :
Delft Univ. of Technol., Delft, Netherlands
Volume :
62
Issue :
5
fYear :
2015
Firstpage :
1961
Lastpage :
1971
Abstract :
The traveling time of scintillation photons from the ionization track to the photodetector varies from photon to photon. For scintillators used in (time-of-flight) positron emission tomography (TOF-)PET systems the resulting optical transit time-spread can have a significant influence on the timing resolution. Using a femtosecond pulsed diode laser in combination with a fast imaging streak camera we measured this time-spread on the picosecond time scale for both polished and etched Ca co-doped and non co-doped LSO:Ce and LYSO:Ce crystals of 3 ×3 ×5 mm3, 3 ×3 ×10 mm3, and 3 ×3 ×20 mm3 in size. Measurements were performed with the crystals wrapped on 5 of their sides in 1 to 4 layers of 0.1 mm thick white reflecting Teflon tape (PTFE). Optical photons can migrate through Teflon tape for some time before they re-enter the crystal. This Teflon time-spread was measured as well. The roughness of the crystal surfaces were determined using a surface profiler. In addition to experiments, the optical transit time-spread was obtained by means of ray-tracing software and compared to experimental data. In addition, an analytical model about optical transit time-spreads was derived.
Keywords :
photodetectors; photoionisation; positron emission tomography; ray tracing; semiconductor lasers; solid scintillation detectors; Teflon time-spread; crystal surface roughness; etched Ca noncodoped LSO:Ce crystal; etched Ca noncodoped LYSO:Ce crystal; fast imaging streak camera; femtosecond pulsed diode laser; ionization track; optical photons; optical transit time-spread; photodetector; picosecond time resolved studies; picosecond time scale; polished Ca noncodoped LSO:Ce crystal; polished Ca noncodoped LYSO:Ce crystal; ray-tracing software; scintillation photon transport; surface profiler; time-of-flight positron emission tomography systems; timing resolution; traveling time; white reflecting Teflon tape; Cameras; Crystals; Measurement by laser beam; Optical imaging; Optical surface waves; Photonics; Surface treatment; Femtosecond laser pulses; optical transit time-spread; ray tracing software; streak camera; surface roughness; teflon tape;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/TNS.2015.2460267
Filename :
7272142
Link To Document :
بازگشت