Development of Resistive Plate Chamber for charge particle detection

Suryanarayan DashUnder the guidance of Prof N K Mondal

TIFR,Mumbai

Objectives:

• Introduction• Main feature of RPC• RPC Fabrication• RPC Theory & Operation• Laboratory test set-up• Analysis of results

Introduction

Detectors:Searching for new particles To study their interaction• RPC the Resistive Plate Chamber detector was

introduced in 1981• Works on the principles of ionization of gas

molecules to detect tracks of charge particles

Main feature

• Very large pulse height• Reduced cost per unit area• Easy fabrication and operation• Simple readout electronics• Good timing capability ,resolution is of the order

of few ns

Components of glass RPC :• Pair of float glass with resistivity 1012 Ω cm with 2 mm

thick• 2 mm spacers• Gas mixture (typically Ar 30%,Freon 62%,isobutane 8%)• Ar: low cost,high specific ionization • Freon:high electron affinity• Isobutane:quencher• Gas nozzles• Graphite coating (good glass adhesion) for HV supply.

After graphite coating the surface resistivity 200-400 kΏ/Finished RPC Frame

Equivalent circuit of glass RPC

RPC principles of operation

Pulse height ~100 mV

μ

Laboratory test set-up with basic circuit

Efficiency of RPC

Typical TDC distribution

Time resolution

Typical ADC distribution

Summary:

• The time resolution of the present RPC ~1.8 ns at 9 kV• The efficiency of our present detector: 90% at 9 kV • Wide acceptance in HEP and Astroparticle community

Thanks a lot .