以單光子方法量測LYSO光產率及其延伸研究

Abstract

Lutetium-Yttrium Oxyorthosilicate，Lu2(1−x)Y2xSiO5 : Ce，又稱”LYSO”，是現代常用的閃爍體之一。與其他常見的閃爍晶體相比，它具有多項優勢，例如短衰減距離、快速衰減時間、非吸濕性和良好的光產率。這些優點對於檢測 511 keV湮滅光子具有優勢，因此成為正電子發射斷層掃描（PET）系統中光電探測的良好候選者。 為了研究 LYSO 的光產率，我們需要知道準確的光量計算方法。我使用光電倍增管（PMT）作為光感測器，並使用發光二極管（LED）作為可調整光源校准PMT 的單光電子。我檢查了 LYSO 的本徵光譜，並以鈉 22 為放射源來研究 LYSO對 511 keV 入射光子的光產率。我還利用在單光電子校正實驗中的經驗，對偏振單光子進行延伸研究。 到目前為止，我們根據這些結果知道可控光源和適當光感測器的組合可以快速測試單個光電子。這對以後的科學研究非常有用，比如任意光量的校正，以及製造不同要求下的單光子源。

Lutetium-Yttrium Oxyorthosilicate, Lu2(1−x)Y2xSiO5 : Ce, also called ”LYSO”, is one of the modern commonly used scintillation crystals. It offers several benefits compared to many common scintillation crystals, such as short attenuation length, fast decay time, non hygroscopic, and comparable light yield. These benefits have advantages for the detection of 511 keV annihilation photons, so it is a good candidate for the photodetector in the positron emission tomography (PET) system. To study the light yield of LYSO, we need to know the exact photon counting method. I use photomultiplier tube (PMT) as the light sensor and use light-emitting diode (LED) as the adjustable light source to calibrate the single photoelectron of PMT. I confirm the LYSO intrinsic spectrum and also use Sodium-22 as a radioactive source to study the light yield of LYSO for 511 keV incident photons. I also use my experience in single photoelectron calibration to conduct an extended study of polarized single photon. With these results so far, we know the combination of a controllable light source and light sensor can quickly test single photoelectron. This is very useful for future scientific research, such as the calibration of arbitrary light amounts and the manufacture of single photon sources with different requirements.