Testing of the Extruded Plastic Scintillators on a Large-Scale for the CMVD

The construction of a cosmic muon veto detector (CMVD) is in progress to shield the mini-Iron Calorimeter detector at IICHEP, Madurai. The goal of the CMVD is to study the feasibility of a shallow depth (100 m) neutrino experiment. The estimated reduction in cosmic muon flux will be \(10^{6}\) at a depth of 1 km. The same order of reduction in cosmic muon flux at a shallow depth (100 m) will be possible, only if the CMVD will have veto efficiency of more than 99.99 \(\%\) and fake rate of less than \(10^{-5}\) . The CMVD will consist of \(\sim \) 4.5 m long extruded plastic scintillators (EPSes), WLS fibre to collect the scintillation photons and the silicon-photomultipliers (SiPMs) for the readout. A total of 760 EPSes will be required in making the CMVD. Two EPSes will be glued together to make one unit called di-counter (DC). It is essential to test all the components (i.e. DCs, SiPMs and the readout electronics) of the CMVD before installation to achieve the required veto efficiency goal. To test the DCs, a coincidence setup is made using additional three DCs to generate a trigger of cosmic muon trajectory. DRS modules are used to collect muon signals of the test DCs. This paper will cover the details of the experimental setup and the test results for all the tested DCs.