Theuseofautomaticscaleselectiontoimprovethespatialandspectral resolutionofascintillator-coupledEMCCD
Theuseofautomaticscaleselectiontoimprovethespatialandspectral resolutionofascintillator-coupledEMCCD
复制标题
使用自动尺度选择来提高闪烁体耦合 EMCCCD 的空间和光谱分辨率
DOI：
10.1016/j.nima.2009.01.075
复制
发表时间：
2009
影响因子：
1.4
通讯作者：
D. R. Smith
中科院分区：
文献类型：
--
作者：
D. Hall;A. Holland;D. R. Smith
电子倍增电荷耦合器件（EMCCD）背后的技术在20世纪90年代末被e2 v技术成功开发。从那时起，已经发现这些低亮度（L3）设备的许多用途，包括监视和许多科学应用。EMCCD通过碰撞电离（或雪崩倍增）现象增加或“倍增”电荷信号，从而允许检测仅几个光子的低信号事件。当与闪烁体耦合时，这种低光能力可用于对来自单个X射线相互作用事件的光子闪光进行成像。闪烁体中的相互作用效应的深度、信号上的散粒噪声和倍增噪声因子的组合导致来自恒定能量X射线源的探测信号的轮廓的大的变化。这种变化导致光谱性能降低，并且可能对光子计数成像器中使用的定心技术产生不利影响。尺度空间的概念在许多方面类似于傅立叶变换或小波变换。自动尺度选择可以通过尺度-空间变换来实现，作为将已知轮廓拟合到所观察到的光子闪光的方法。在这里检查的背景下，光子计数EMCCD探测器和模拟和实验数据中得到的结果进行比较的过程。通过对拟合过程和结果的分析，讨论了其对成像性能和光谱分辨率的影响。
The technology behind the Electron-Multiplying Charge Coupled Device (EMCCD) was successfully exploited by e2v technologies in the late 1990s. Since then, many uses have been found for these low light level (L3) devices including surveillance and many scientific applications. The EMCCD increases or ‘multiplies’ the charge signal by the phenomenon of impact ionisation (or avalanche multiplication) allowing the detection of low signal events of only a few photons. When coupled with a scintillator, this low light capability can be used to image photon flashes from individual X-ray interaction events. The combination of depth of interaction effects in the scintillator, shot noise on the signal and the multiplication noise factor lead to large variations in the profile of the detected signal from a constant energy X-ray source. This variation leads to reduced spectral performance and can have adverse effects on the centering techniques used in photon-counting imagers. The concept of scale-space is similar in many ways to the Fourier or wavelet transforms. Automatic scale selection can be implemented through the scale-space transform as a method of fitting a known profile to the observed photon flash. The process is examined here in the context of the photon-counting EMCCD detector and the results obtained in both simulated and experimental data compared. Through the analysis of the fitting process and the results achieved, the implications on imaging performance and spectral resolution are discussed.