There are many sources of position dependent variation of the intrinsic gain of a single gap RPC, e.g. variation of the thickness of the glass electrodes, the buttons and spacers, different composition of the gas mixture due to improper gas flow, leakage etc. One of the dominant components of the time resolution of a large area single gap RPC is this position dependent gain. Also, there is a variation of timing information as a function of the strip multiplicity as well as the lateral position of the trajectory in the RPC strip coordinate. This paper describes the technique of offline time correction to achieve a time resolution better than a ns. This technique is validated using a large cosmic ray dataset collected with a stack of twelve, 1×1 m² RPCs at TIFR. This paper also mentions a few alternate solutions to improve the time resolution during the operational phase of the INO-ICAL experiment. All these solutions are not only valid for INO, but also for any experiment with large RPC detectors.

The Cosmic Ray Extremely Distributed Observatory (CREDO) pursues a global research strategy dedicated to the search for correlated cosmic rays, so-called Cosmic Ray Ensembles (CRE). Its general approach to CRE detection does not involve any a priori considerations, and its search strategy encompasses both spatial and temporal correlations, on different scales. Here we search for time clustering of the cosmic ray events collected with a small sea-level extensive air shower array at the University of Adelaide. The array consists of seven one-square-metre scintillators enclosing an area of 10 m × 19 m. It has a threshold energy ~0.1 PeV, and records cosmic ray showers at a rate of ~6 mHz. We have examined event arrival times over a period of over 2.5 years in two equipment configurations (without and with GPS timing), recording ~300 k events and ~100 k events. We determined the event time spacing distributions between individual events and the distributions of time periods which contained specific numbers of multiple events. We find that the overall time distributions are as expected for random events. The distribution which was chosen a priori for particular study was for time periods covering five events (four spacings). Overall, these distributions fit closely with expectation, but there are two outliers of short burst periods in data for each configuration. One of these outliers contains eight events within 48 s. The physical characteristics of the array will be discussed together with the analysis procedure, including a comparison between the observed time distributions and expectation based on randomly arriving events.

The INO-ICAL is a proposed neutrino physics experiment, which will be made of 50 kTon of low carbon magnetized steel layers, tiled with 4 m × 2 m ×56 mm thick plates, alternating with layers of RPCs as a sensitive detector. The GEANT4 toolkit is used to simulate the matter particle interactions and digitization is based on the data collected in the prototype detector at Madurai. The momentum and direction of charged particle tracks are estimated using the Kalman filter technique and reconstruction of hadron shower using a clustering algorithm. In this paper, the measurement of the momentum of fully contained charge particles using the total path length of the trajectory will be discussed and compared with the Kalman filter technique. A clustering algorithm for the measurement of the energy of hadronic showers along with its direction will also be discussed. This hadron clustering algorithm is used first time in the ICAL detector simulation.

We have investigated the particle size effect on the compressibility of nano crystalline Germanium phase‐I in pressure range of 0–15 GPa. In the present work, the Tait’s equation of state (EOS) has been modified to predict the high pressure behaviour of nano crystalline Germanium of three different particle sizes 100 nm, 49 nm and 13 nm along with its bulk modulus counterpart. Our results on the study of compressibility show that nano size samples are less compressible than bulk materials which are in agreement with the Hall‐Petch effect.