Scintillation and Spectroscopic Characteristics of 90% Lu LGSO With Variable Decay Times
Scintillation and Spectroscopic Characteristics of 90% Lu LGSO With Variable Decay Times
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DOI：
10.1109/tns.2016.2619179
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发表时间：
2017-01-01
影响因子：
4.4
通讯作者：
Lecomte, Roger
中科院分区：
文献类型：
--
作者：
Loignon-Houle, Francis;Pepin, Catherine M.;Lecomte, Roger
十多年前，人们引进了衰变时间常数在30-45 ns范围内的高含量LGSO[Lu1.8Gd0.2SiO5：Ce]闪烁体。最初经过实验开发，逐步建立了批量生产，成熟的90%的LGSO闪烁体已经具备了稳定的特性。这项工作的目的是评估最近产生的90%Lu LGSO具有不同衰减时间的闪烁特性，使用雪崩光电二极管(APD)读出。对快(约30 ns)、标准(约40 ns)和慢(约47 ns)的90%Lu LGSO样品从顶端、中端和底端提取成铸锭进行了研究。无论样品是在哪里获得的，来自同一钢锭的样品的衰减时间和中心发射波长都是稳定的。慢、标准和快LGSO闪烁体的光电子产额总体上表现出良好的均匀性。在511keV下，它们的平均光电子产额分别为34000+/-1000Phe/MeV、31200+/-500Phe/MeV和28000+/-2000Phe/MeV，没有任何明显的趋势或偏差。光子产额和衰变时间的结合导致了高的初始发射率和对三类衰变时间的914+/-18ps的亚纳秒时间分辨性能。慢速LGSO在511keV处的平均能量分辨率为10+/-2%，而标准和快速LGSO的能量分辨率相同，为11+/-3%。还研究了光产额与辐照能量的非正比关系。在60keV电压下，线性度偏差达到19+/-2%。
High lutetium content LGSO [Lu1.8Gd0.2SiO5:Ce] scintillators with decay time constants in the range 30-45 ns were introduced some ten years ago. At first an experimental development, mass production was gradually established and mature 90% Lu LGSO scintillators with stable characteristics have become available. The aim of this work was to assess the scintillation characteristics of recent 90% Lu LGSO production with different decay times using avalanche photodiode (APD) readout. Samples of Fast (similar to 30 ns), Standard (similar to 40 ns) and Slow (similar to 47 ns) 90% Lu LGSO, extracted from top, middle and bottom positions into ingots, have been investigated. The decay time and central emission wavelength were found to be stable for samples from the same ingot, irrespective of the position where the sample was obtained. The photoelectron yields of Slow, Standard and Fast LGSO scintillators generally showed good uniformity. Their average photoelectron yields at 511 keV were respectively 34 000 +/- 1 000 phe/MeV, 31 200 +/- 500 phe/MeV and 28 000 +/- 2 000 phe/MeV without any definite trend or bias with respect to position in ingots. The combination of photon yield and decay time results in high initial emission rate and a subnanosecond time resolution performance of 914 +/- 18 ps for the three categories of decay times. The average energy resolution at 511 keV of Slow LGSO was 10 +/- 2% whereas Standard and Fast LGSO samples had identical energy resolution of 11 +/- 3%. The light yield non-proportionality as a function of irradiation energy was also investigated. At 60 keV, the departure from linearity reached 19 +/- 2%.