Performance of the INFN Camera calibration device of the first Large Size Telescope in the Cherenkov Telescope Array
Performance of the INFN Camera calibration device of the first Large Size Telescope in the Cherenkov Telescope Array
复制标题
切伦科夫望远镜阵列第一台大口径望远镜INFN相机标定装置性能
DOI：
10.22323/1.358.0757
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
F. Ferrarotto
中科院分区：
文献类型：
--
作者：
M. Palatiello;M. Iori;F. Cassol;D. Cauz;F. Ferrarotto
2018年底，为切伦科夫望远镜阵列(CTA)天文台提出的第一个大尺寸大气切伦科夫望远镜(LST-1)的原型已经在西班牙加那利群岛拉帕尔马的Observatorio del Roque de los Muchachos完成。LST-1相机拥有1800多个光电倍增管(PMT)，需要精确和规则的平场光电子(P.E.)校准。
我们介绍了安装在LST-1 DISH中心的系统(Camera Caliation Box，CaliBox)的特点和性能，该系统为相机PMT提供光学校准，动态范围高达10^3美元/秒。每像素(1像素=1 PMT)。
CaliBox由波长为355微米(对应于光电倍增管量子效率的最大值)和400微秒脉冲宽度的脉冲紫外光激光器、一套滤光片以保证每个像素上的光子动态范围以及漫射的Ulbricht球体组成，以将激光积分并均匀地散布到28微米外的相机平面上。CaliBox被设计为密封并充满干燥空气，使系统与外部环境完全隔离，并保持受控的低内部相对湿度。
一个额外的内部校准系统提供了绝对(和相对)的体育锻炼次数。对于每个过滤器组合，除了自诊断机制之外。
该系统完全由内部ODROID-C1+板管理，可通过开放平台通信的统一架构(OPC-UA)协议进行远程控制。
At the end of 2018, the prototype of the first Large Size atmospheric Cherenkov Telescope (LST-1) proposed for the Cherenkov Telescope Array (CTA) observatory has been completed at the Observatorio del Roque de Los Muchachos in La Palma (Canary Islands, Spain). The LST-1 camera, with more than 1800 photomultipliers (PMTs), requires a precise and regular flat field photo-electron (p.e.) calibration.
We present the characteristics and performance of the system (Camera Calibration Box, CaliBox), installed at the center of the LST-1 dish, which provides the optical calibration for the camera PMTs, over a large dynamic range up to $10^3$ p.e. per pixel (1 pixel = 1 PMT).
The CaliBox consists of a pulsed UV laser with a wavelength of 355 nm (corresponding to the maximum of the PMT quantum efficiency) and a 400 ps pulse width, a set of filters to guarantee a large dynamic range of photons on each pixel, and a diffusing Ulbricht sphere to integrate and uniformly spread the laser light over the camera plane 28 m away. The CaliBox is designed to be hermetically closed and filled with dry air to make the system completely isolated from the external environment and maintain a controlled low internal relative humidity.
An additional inter-calibration system provides the absolute (and relative) number of p.e. for each filter combination in addition to a self-diagnose mechanism.
The system is completely managed by an internal ODROID-C1+ board , which can be remotely controlled via an Open Platform Communication's Unified Architecture (OPC-UA) protocol.