High-Performance and Low-Noise Front-End Electronics for GRAPES-3 Muon Telescope

Abstract

Cosmic Ray Laboratory – TIFR, Ooty, India is operating the largest tracking muon telescope as a component of the GRAPES-3 (Gamma Ray Astronomy PeV EnergieS at phase – 3) experiment. The basic building blocks of the telescope are proportional counters (PRCs), a large number of which are fabricated in-house for the planned expansion of the existing muon telescope to double its area and enhance the solid angle coverage from 2.3 sr to 3.7 sr as well as achieving higher sensitivity for studying space weather and atmospheric phenomena, cosmic ray composition, etc. The existing muon telescope consists of 3712 PRCs, and after the planned expansion which requires an additional 3776 PRCs, the area of the telescope will increase from the present 560 m\(^{2}\) to 1130 m\(^{2}\). Each of the PRCs will need to be individually equipped with front-end electronics for processing the output signals. The output pulses from PRCs are extremely feeble, and their charges are in the order of \(\sim \)100 pC. The tiny signal has to be isolated from potential sources of noise before its processing. High-performance, ultra-low noise, and cost-effective electronics are designed, developed, and mass-produced in-house for about 8000 channels of PRCs. The quality of data is improved significantly by interfacing the new electronics with PRCs of the existing muon telescope due to improved signal-to-noise (S/N) ratio, and the data acquisition is made effective as a result of multifold improvement achieved by avoiding undesired interruptions in the data.