fully functional mini-ICAL
mini-ICAL iron stack, when under construction
Engineers Making Particle Detector for INO
INO Prototype detector at TIFR
INO Collaboration Meeting, Nov 2019
A conscious and consistent effort was initiated to design local components and solutions for all the engineering aspects of the project. A large-scale detector R&D effort was undertaken to develop RPCs of 2m x 2m in size for the first time in the country. We also built multi-gap RPCs and established proof of principle of their application for PET imaging. Generations of gas systems, including a closed-loop unit were developed and built with help of a local industry. The electronics comprising of indigenously developed custom ASICs and high-end FPGAs as well as programmable trigger and high-speed data acquisition systems were developed. The detectors, instrumentation and electronics that we developed are finding extensive applications by other experiments within department, institute and beyond. A brief account of these developments is given below.
The ICAL detector proposes to use 2m 2m RPCs to cover about 100,000m2 of detector coverage – the largest in the world. RPCs of this large area had required design of and development of special handling system and jigs for their assembly and handling. We have successfully designed and developed this infrastructure. Several RPC detector stacks – including the magnetised mini-ICAL prototype detector operational at Madurai are in operation for many years establishing long-time performance of these large area RPCs. Large area RPCs are being successfully mass produced in the industry now.
The RPC R&D that the INO project initiated and mastered was transformed to many research and academic institutes spread all over the country. A large number of faculties, students and engineers were trained in the INO labs and we helped them all to successfully develop RPC laboratories at their own institutions. Some of these groups have also taken up detector projects to build RPC systems for other experiments as well using based on their expertise gained through collaboration with INO project. A huge number of industries were roped in to develop components and processes required for, as well as for large scale production of high-quality RPC detectors needed for ICAL experiment.
During the process of RPC detector production, several processes are required on the raw materials, often done at different places and times. In order to track the quality of the finished product, we perform many quality control tests and checks. Data from all these measurements are logged into a specially design database utility which was developed inhouse. This utility is found to be invaluable for tracking the quality of the detectors produced by the industry and same can be adapted for similar needs.
Many of the ICAL electronics components will easily find applications in similar experiments. The AFE, DFE boards as well high voltage modules could be readily used with many detectors. Besides, we also developed many boards and modules as spinoff of our development work. A compact DAQ board based on a low-end Max10 FPGA for handling complete read of four scintillator paddles/PMTs can be used to quickly setup cosmic ray test stands, mobile muon rate monitors and so on.
We also developed a number of back-end software applications using clever implementation of communication standards and hardware. For example, we port cosmic ray muon track displays from our detector stacks onto web browsers, a feature which is used for outreach purposes besides remotely monitoring the status of our detector stacks.
We also started developing a number of online monitoring systems using free and open source computer-software applications such as Nagios. Nagios offers monitoring and alerting services for servers, network switches, applications and services. It alerts users when things go wrong and alerts them a second time when the problem has been resolved. This framework is easy to adopt for any such applications.
We have also trained a large number of graduate students and faculty from INO collaborating institutes and helped them setting up RPC labs at their institutions. Besides graduate students from INO’s own Ph.D. programme, there are many students who work on INO physics problems as well as detector development aspects towards their thesis. We train them and help them by building detectors and setting up experiments in the INO labs at Mumbai and Madurai.