籽晶保护条件下铈掺杂溴化镧晶体生长及其性能-《集美大学学报（自然科学版）》

文章信息/Info

Title:: Growth of Ce3+ Doped LaBr3 with Protected-Seed and Its Scintillation Properties

Author(s):: ZHANG Zhicheng; FANG Shenghao; (Fujian Institute of Research on the Structure of Matter,CAS,Fuzhou 350002,China )

Keywords:: LaBr3; energy resolution; array; two-dimensional scatter image; position resolution

摘要:: 为定向生长出铈掺杂溴化镧（LaBr3:Ce）晶体，改进了坩埚下降法，并在籽晶接种过程引进冷却气体的保护装置。生长出的LaBr3:Ce晶体在137Cs放射源辐照下，其能量分辨率为3.08%，衰减时间为20.1 ns。采用多通道DRS4采集系统，以XP20D0型光电倍增管耦合 Ф 20 mm×5 mm 溴化镧器件作为开始道探测器，H8500型光电倍增管耦合LaBr3:Ce阵列作为被测停止道探测器，放射源为22Na（511 keV）。制备了6×6的LaBr3:Ce阵列，单根晶体条的尺寸为2 mm×2 mm×15 mm。利用数字化波形分析法，获得阵列的清晰二维散点图和一维位置谱，阵列x和y方向的位置分辨率分别为1.01 mm和0.89 mm。制备出的LaBr3:Ce晶体具有优异的能量分辨率和位置分辨率，可以应用于PET等医学成像技术领域。

Abstract:: Ce3+ doped LaBr3 crystals were grown by a modified Bridgman technique with selective-seed,which was protected under cool gas.LaBr3:Ce scintillator has an FWHM energy resolution of 3.08% and a decay time of 20.1 ns under γ-ray excitation of 137Cs radioactive source．A 6×6 array of LaBr3 scintillator pixels was developed with a pixel size of 2 mm×2 mm×15 mm.A muti-channels DRS4 board system was used to process signals from a pair of detectors with XP20D0 PMT coupled with a Ф 20 mm×5 mm LaBr3:Ce scintillator as START Channel,and H8500 PMT coupled with a LaBr3:Ce scintillators array as tested STOP Channel,which were placed apart from a 22Na source for 511 keV γ-ray.The results based on analysis of digital waveform methods show that the DRS4 system has clear black scattered points on two-dimensional crystal scatter image.While the one-dimensional position images show that the position resolutions are 1.01 mm and 0.89 mm,in xand ydirections respectively.The excellent energy resolution and position resolution properties of LaBr3:Ce samples,indicate that it can be used in the nuclear image technique such as PET data acquisition system．