arXiv subjects

Rajesh Ganai

Publications and source records attributed to Rajesh Ganai.

5 recordsLinked to original sources

arXiv2018

A Proof-of-principle for Time-Of-Flight Positron Emission Tomography Imaging

Time-Of-Flight (TOF) is a noble technique that is used in Positron Emission Tomography (PET) imaging worldwide. The scintillator based imaging system that is being used around the world for TOF-PET is very expensive. Multi-gap Resistive Plate Chambers (MRPCs) are gaseous detectors which are easy to fabricate, inexpensive and have excellent position and timing resolution. They can be used as a suitable alternative to highly expensive scintillators. For the sole purpose of TOF-PET, a pair of 18 cm $\times$ 18 cm, 5 gap, glass-based MRPC modules have been fabricated. Our main aim was to determine the shift in the position of the source (Na-22) with these fabricated MRPCs. In this document, the details of the experimental results will be presented.

physics.ins-det↗

arXiv2018

Development and Characterization of 6-gap Bakelite Multi-gap Resistive Plate Chamber

The Multi-gap Resistive Plate Chamber (MRPC) is an advanced form of Resistive Plate Chamber (RPC) detector where the gas gap is divided into sub-gaps. MRPCs are known for their good time resolution and detection efficiency for charged particles. They have found suitable applications in several high energy physics experiments like ALICE in LHC, CERN, Geneva, Switzerland, and STAR in RHIC, BNL, USA. As they have very good time resolution and are of low cost, they can be a suitable replacement for very expensive scintillators used in Positron Emission Tomography Imaging. The MRPCs that are being used nowadays are developed with glass electrodes. We have made an attempt to develop a 6-gap MRPC using bakelite electrodes. The outer electrodes are of dimensions 15 cm $\times$ 15 cm $\times$ 0.3 cm and the inner electrodes are of dimension 14 cm $\times$ 14 cm $\times$ 0.05 cm. The glossy finished electrode surfaces have not been treated with any oil like linseed, silicone for smoothness. The performance of the detector has been studied measuring the efficiency, noise rate and time resolution with cosmic rays. This effort is towards the development of a prototype for Positron Emission Tomography with the Time-Of-Flight technique using MRPCs. Details of the development procedure and performance studies have been presented here.

physics.ins-det↗

arXiv2017

Physics Potential of the ICAL detector at the India-based Neutrino Observatory (INO)

The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.

physics.ins-det↗

arXiv2016

Fabrication and Characterisation of Oil-Free Large High Pressure Laminate Resistive Plate Chamber

A large (240 cm $\times$ 120 cm $\times$ 0.2 cm) oil-free High Pressure Laminate (HPL), commonly referred as "bakelite", Resistive Plate Chamber (RPC) has been developed at VECC-Kolkata using locally available P-302 OLTC grade HPL. The chamber has been operated in streamer mode using Argon, Freon(R134a) and Iso-butane in a ratio of 34:57:9 by volume. The electrodes and glue samples have been characterised by measuring their electrical parameters like bulk resistivity and surface resistivity. The performance of the chamber has been studied by measuring the efficiency, its uniformity and stability in detection of cosmic muons. Timing measurement has been performed at a central location of the chamber. The chamber showed an efficiency $>$95$\%$ and time resolution ($σ$), at the point of measurement, $\sim$0.83 ns at 9000V. Details of the material characterisation, fabrication procedure and performance studies have been discussed.

physics.ins-det↗

arXiv2016

Long Term Performance Studies of Large Oil-Free Bakelite Resistive Plate Chamber

Several high energy physics and neutrino physics experiments worldwide require large-size RPCs to cover wide acceptances. The muon tracking systems in the Iron calorimeter (ICAL) in the INO experiment, India and the near detector in DUNE at Fermilab are two such examples. A (240 cm $\times$ 120 cm $\times$ 0.2 cm) bakelite RPC has been built and tested at Variable Energy Cyclotron Centre, Kolkata, using indigenous materials procured from the local market. No additional lubricant, like oil has been used on the electrode surfaces for smoothening. The chamber is in operation for $>$ 365 days. We have tested the chamber for its long term operation. The leakage current, bulk resistivity, efficiency, noise rate and time resolution of the chamber have been found to be quite stable during the testing peroid. It showed an efficiency $>$ 95$\%$ with an average time resolution of $\sim$0.83 ns at the point of measurement at 9000 V throughout the testing period. Details of the long term performance of the chamber have been discussed.

physics.ins-det↗