Study of High Resolution and High Speed Imaging for the Cherenkov Light and Air Fluorescence Light induced by Air Showers

最近，我们利用成像切伦科夫望远镜观测到由空气阵雨引起的切伦科夫光，以寻找TeV伽马射线，并利用成像相机取得了非常重要的结果。本文研制了一种由图像增强器和CCD组成的新型高速摄像机系统。为观测空气簇射引起的切伦科夫光和荧光，研制了高分辨率切伦科夫望远镜的新光学设计。使用这些系统可以降低阈值能量，提高高能伽玛射线和宇宙射线入射方向的精度。在本研究中，我们开发了以下新的摄像系统和光学系统。1)我们制作了一个成像系统，该成像系统由两个图像增强器（I.I.）组成，其中一个图像增强器直径为10cm，另一个具有高速门。该系统在入口表面具有良好的空间分辨率，rms为0.6mm，并且能够测量单个光电子水平。2)光电倍增管和高速电路可以在100ns左右的范围内产生触发信号。3)高速摄像机的成像画面可以随机拍摄，最大速率为250/秒。4)设计了一种新型切伦科夫望远镜光学元件，仿真得到了视角为4度，角分辨率约为0.03度的光学元件。这些系统的性能将由位于兵库县乌谷山的柯南切伦科夫望远镜进行测量。这些系统具有测量单光电子的高灵敏度，高空间分辨率和宽视场。因此，它们将能够用于各种研究领域，如宇宙射线物理学、基本粒子物理学，以及更广泛的科学、工程和医学领域。

We have recently observed the Cherenkov light induced by air showers to search for TeV gamma rays using imaging Cherenkov telescopes and achieved very important results using imaging cameras. In the present study we developed a new high speed video camera system consisting of image intensifiers and a CCD. New optics design of high resolution Cherenkov telescope is also developed to observe the Cherenkov light and fluorescent light induced by the air showers. Lower threshold energy and better precision of coming direction of the high energy gamma rays and cosmic rays are expected using these systems.We have developed the following new camera system and optics system in the present study.1)We made an imaging system which consists of two image intensifiers (I.I.), one with a large diameter of 10cm and another with a high speed gate. This system was measured to have a good spatial resolution of 0.6mm in rms at the entrance surface, and was found to be able to measure a single photoelectron level.2)Trigger signals can be generated by photomultipliers and high speed electric circuits within about 100ns.3)Imaging picture frames of the high speed video camera can be randomly taken at a maximum rate of 250/sec.4)A new type optics for the Cherenkov telescopes was designed and the angular resolution of about 0.03 degree with a viewing angle of 4 degrees was achieved by a simulation.Performance of these systems will be measured by the Konan Cherenkov telescope placed at Ooya Mt. in Hyogo pref. These systems have high sensitivity to measure the single photoelectrons, high spatial resolution and wide field of view. Therefore, they will be able to be used in various research fields such as cosmic ray physics, elementary particle physics, and wider fields of science, engineering and medical science.