A prototype called mini-ICAL, with 1/600 of the weight of ICAL, has been constructed and installed in the PtRC transit campus at Madurai, to gain experience in the building of a large-scale electromagnet, to study the detector performance, and to test the ICAL electronics in the presence of fringe magnetic fields. This 4m × 4m × 1.1m detector has 11 iron layers, and 20 RPCs of 1.95m x 1.92m have been inserted in the 10 layers of gaps, in the central region. Mini-ICAL has been in operation since 2018, and is collecting cosmic ray muon data. The general construction, magnet, RPC design, gas system, electronics, trigger, DAQ and backend software systems of the mini-ICAL are exactly the same as those planned for the ICAL and its engineering prototype (e-ICAL) detector. Apart from its own physics motivations, mini-ICAL is largely meant to validate the engineering designs of the ICAL and e-ICAL.
Photograph alongside shows construction activities of mini-ICAL, with active contributions by INO graduate students and also large number of internship students from local educational institutions. A large number of students were invited to get the hands-on experience of building of particle detectors, assembly, testing, installation and commissioning activities, as well as to learn from experts the basic science concepts associated with various sub-systems of mini-ICAL.
The major components of the mini-ICAL detector are as follows: