# Quark Matter 2018

13-19 May 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

## Triple and quadruple GEM detectors for high energy physics experiments

15 May 2018, 17:00
2h 40m
First floor and third floor (Palazzo del Casinò)

### First floor and third floor

#### Palazzo del Casinò

Poster Future facilities, upgrades and instrumentation

### Speakers

Mr Rajendra Nath Patra (Variable Energy Cyclotron Centre (IN))Dr Tapan K. Nayak (CERN, Geneva and VECC, Kolkata)

### Description

GEM based detectors are now almost an integral part of high energy physics (HEP) experiments. Most of the experiments have, however, used triple GEM detectors. A quadruple GEM detector specially designed for low ion back flow will be used for the readout of the upgraded TPC in ALICE experiment. We present the study of a triple and a quadruple GEM detector and compare their performances in order to understand the usefulness of increasing the number of GEM foils and obtain better operating parameters to suit the requirements of HEP experiments.

The detectors have been assembled in standalone configuration and tested with $^{55}$Fe X-ray and $^{106}$Ru-Rh $\beta$-source using Ar/CO$_2$ gas mixtures with 90:10 and 70:30 proportions. Effective gain and energy resolution have been measured using $^{55}$Fe source. The efficiency is measured using the $^{106}$Ru-Rh $\beta$-source and a coincidence setup consisting of three scintillators. In addition, the uniformity of the gain and energy resolution of the GEM detectors have been investigated by dividing the active area in 7$\times$7 zones.

It was found that quadruple GEM detector operates at less voltage across individual GEM foil ($\Delta$V$_{GEM}$) compared to the triple GEM detector. It is also found that the energy resolution of the detector deteriorates in case of quadruple GEM detector. Time resolution of the detectors is also measured and the obtained value is $\sim$10 – 13 ns at the operating voltage.

We have studied the electron transparency of the quadruple GEM detector with different drift field configurations for understanding the charge transfer phenomena through the GEM foils. An optimum drift field for the maximum transparency is obtained from the results. Garfield simulation studies are in progress for understanding the working phenomena and results of the test.

Content type Experiment Presenter name already specified

### Primary authors

Mr Rajendra Nath Patra (Variable Energy Cyclotron Centre (IN)) Rama N. Singaraju (Department of Atomic Energy (IN)) Dr Saikat Biswas (Bose Institute (IN)) Dr Tapan K. Nayak (CERN, Geneva and VECC, Kolkata) Y. P. Viyogi (Department of Atomic Energy (IN))