Performance of the triple GEM detector built using commercially manufactured GEM foils in India

Abstract

The Gas Electron Multiplier (GEM) detectors has been utilized for various applications due to their excellent spatial resolution, high rate capabilities and flexibility in design. The GEM detectors stand as a promising device to be used in nuclear and particle physics experiments. Many future experiments and upgrades are looking forward to use this technology leading to high demand of GEM foils. Until now, CERN is the only reliable manufacturer and distributor of GEM foils, but with technology transfer, few other industries across the globe have started manufacturing these foils employing the same photo-lithographic technique. The Micropack Pvt. Ltd. is one such industry in India which produced first few 10 cm × 10 cm GEM foils, which were then distributed to few collaborating partners for testing reliability and performance of foils before they can be accepted by the scientific community. Characterization of three such foils have already been performed by studying their optical and electrical properties. Using these foils a triple GEM detector has been built and various performance characteristics have been measured. In this paper, we specifically report measurements on gain, resolution and response uniformity, by utilizing local quality control set-ups existing at University of Delhi.

GEM foil characterization in cost-effective, and efficient way and attempt made to use it as an imaging detector

“…The detector has shown linear behavior and 3 Hz of the fake signal at a maximum applied voltage of 5000V (shown in Figure 6), at 140 mV of threshold across discriminator. Gain [4] of the detector was measured in Ar : CO 2 (70:30) gas mixture flushing at 3 l/h for detector current 650 µA to 730 µA. We observe stable and linear behavior of gain on a logarithmic scale.…”

“…10 cm × 10 cm triple layer GEM detector with 3/1/2/1 gaps in mm was assembled and inspected its nature under high voltage up to 5000V in pure CO 2 to see ohmic behavior and the fake signal coming from the detector. Full assembly procedure, setup, and data taking chain can be found in reference [4]. The detector has shown linear behavior and 3 Hz of the fake signal at a maximum applied voltage of 5000V (shown in Figure 6), at 140 mV of threshold across discriminator.…”

The qualification of GEM detector and its application to imaging

“…The prototype GEM detector with 3/1/2/1 (mm) gas gap [12] is assembled using three fully tested 10 cm × 10 cm GEM foils, a drift foil (only one side copper plated), and a two-dimensional (2D) readout (RO) board. The 3 mm gap between the drift foil and the first GEM foil, 1 mm gap between the first and second GEM foils, 2 mm gap between the second and third foils, and 1 mm gap between the third foil and the readout board are all part of this gap A voltage divider [22] network is used to power up the GEM foils and drift foils through a single high voltage (HV) power supply. Each foil is protected using 10 MΩ resisters against excess current during possible discharges or sparks produced during the operation.…”

A new technique to establish the uniformity of the induction gap in GEM based detector

“…The data was recorded using the SRS shown in Figure 2, which has been developed by the RD51 collaboration at CERN. The CMS GEM collaboration use this system for the quality assurance of the GEM detector [14,15,16]. The SRS has been used to control and read the APV25 front end ASIC.…”