Development of wavelength-independent back-illuminated CCD detector and its application

在过去的4年中，我们通过实验验证了背照CCD探测器在可见光、真空紫外和x射线等离子体光谱中的许多优点。通过本课题的研究，使CCD探测器的运行没有出现任何技术故障。最重要的结论是，对这种光谱变化的测量没有限制。本研究考察了CCD探测器在灵敏度稳定性和时空分辨率方面的优良特性，可以应用于其他科学研究领域。在可见光区，将背照式CCD与带图像增强器（II）的光电二极管阵列（PDA）进行了比较。在强可见光输入引起的探测器突然破坏、长周期灵敏度变化、脚位光谱轮廓形状、空间分辨率、信号检测动态范围、时间分辨率、工作稳定性、信噪比等方面，CCD的特性都明显优于PDA+II。在VUV区域，将背照CCD的特性与带有微通道板（MCP）的PDA进行了比较。探测器安装在20cm法入射光谱仪上，用CHS和LHD等离子体光进行检测。结果与可见的情况相同。CCD探测器的质量要好得多。特别是，真空压力的增加对CCD没有任何损害，尽管真空压力的增加对微波等离子体的工作非常敏感，CCD容易受到压力的增加而损坏。此外，利用CCD作为VUV光谱仪的探测器，我们可以使用0阶（可见光）光在探测器平面上精确地监测焦点图像，从而使光栅的设置和调整变得非常容易。在x射线区，比较了CCD探测器与常用的多线比例计数器（MWPC）的特性。在x射线辐射中。等离子体的强度是电子温度的一个大函数。然后，x射线强度在放电过程中发生很大变化，并且很容易通过额外加热来增强。因此，x射线光谱学受到探测器信号动态范围的限制。采用CCD探测器代替MWPC，使探测器的动态范围提高了1000倍。迄今为止，用x射线光谱法测量离子温度存在相当大的误差条。然而，我们可以完全解决CCD探测器的问题。少

During past 4 years we experimentally verified many advantages on back-illuminated CCD detector, which was used in visible, vacuum ultraviolet (VUV) and x-ray plasma spectroscopy. The CCD detector was being operated without any technical trouble through this research. As a most important result it was concluded that no limit on the measurement existed for such variations of spectroscopy. Excellent characteristics of the CCD detector on the stability of sensitivity and the spatial-and time-resolution, which were examined in this research, can be applicable to another field of scientific research.In the visible region, the characteristics of the back-illuminated CCD were compared with photodiode array (PDA) with image intensifier (II) used for the visible spectroscopy. The characteristics of the CCD was much superior to the PDA+II in many terms of sudden detector destruction due to strong visible light input, sensitivity change over long period, spectral profile shape at foot position, s … More patial resolution, dynamic range for signal detection, time resolution, operational stability, S/N ratio etc.In the VUV region, the characteristics of the back-illuminated CCD were compared with PDA with micro-channel plate (MCP). The detectors were installed on a 20cm normal incidence spectrometer and checked using CHS and LHD plasma light. The result was the same as the visible case. The CCD detector had much better quality. Especially, the CCD did not show, any damage to increase of the vacuum pressure of the spectrometer, although the operation of M C P was very sensitive to the pressure increase and the CCD was easily damaged by the pressure increase. In addition, the use of CCD as a detector of VUV spectrometer enabled us a very easy setting and adjustment of the grating because we could exactly monitor the focus image at the detector plane using 0th-order (visible) light.In the x-ray region, the characteristics of the CCD detector were compared with usually used multiwire proportional counter (MWPC ). In x-ray emissions. from plasmas the intensity is a large function of electron temperature. Then, the x-ray intensity largely changes during a discharge and is easily enhanced by an additional heating. As a result, the x-ray spectroscopy was limited by the detector signal dynamic range. The use of the CCD detector instead of the MWPC increased the detector dynamic range by 1000 times. Until now the ion temperature measurement by the x-ray spectroscopy included a considerably large error bar. However, we could completely resolve the problem using the CCD detector. Less