Related papers: Investigation of Ion Backflow in Bulk Micromegas D…
Ion backflow is one of the effects limiting the operation of a gaseous detector at high flux, by giving rise to space charge which perturbs the electric field. The natural ability of bulk Micromegas to suppress ion feedback is very…
We present ion backflow measurements in a Micromegas (MICRO-MEsh GASeous detector) TPC device developed for the next high energy electron-positron linear collider under study and a simple explanation for this backflow. A Micromegas…
In gaseous tracking detectors with a large gaseous volume multiple layers of Gas Electron Multipliers (GEM) can be used to block positive ions from flowing back into the active volume, which is detrimental to the tracking performance. We…
A systematic study is performed to measure the ion backflow fraction of the GEM detectors. The effects of different voltage configurations and Ar/CO_2 gas mixtures, in ratios of 70:30, 80:20 and 90:10, on positive ion fraction are…
Gaseous detectors are used in both low energy and high energy physics experiments. The present day gaseous detectors, i.e., the Micro-Pattern gaseous detectors (MPGD) are more efficient and fast. Gas Electron multiplier (GEM) is quite well…
The present work involves the comparison of various bulk Micromegas detectors having different design parameters. Six detectors with amplification gaps of $64,~128,~192,~220 ~\mu\mathrm{m}$ and mesh hole pitch of $63,~78 ~\mu\mathrm{m}$…
A novel concept for ion blocking in gas-avalanche detectors was developed, comprising cascaded micro-hole electron multipliers with patterned electrodes for ion defocusing. This leads to ion blocking at the 10^{-4} level, in DC mode, in…
A comprehensive study, supported by systematic measurements and numerical computations, of the intrinsic limits of multi-GEM detectors when exposed to very high particle fluxes or operated at very large gains is presented. The observed…
Gas electron Multipliers (GEM) are a new generation of gaseous avalanche devices in the Micro Patterned Gaseous Detector category. GEMs are widely used in both nuclear and high energy experiments as well as in medical science. Several…
Micro-Pattern Gas Detectors (MPGDs) are extensively employed in modern high-energy and nuclear Physics experiments because of their excellent spatial resolution, high rate capability, and operational stability. Among these, the Gas Electron…
We have developed MICROMEGAS (MICRO MEsh GASeous) detectors for detecting {\alpha} particles emitted from an 241-Am standard source. The voltage applied to the ionization region of the detector is optimized for stable operation at room…
A study of the dynamics of the positive charges in liquid argon has been carried out in the context of the future massive time projection chambers proposed for dark matter and neutrino physics. Given their small mobility coefficient in…
Micro-Pattern Gas Detectors (MPGDs) represent a category of gaseous ionization detectors that utilize microelectronics. They feature a remarkably small distance between the high potential difference anode and cathode electrodes and are…
The MICROMEGAS (MICRO-MEsh GAseous Structure) charge amplification structure has found wide use in many detection applications, especially as a gain stage for the charge readout of Time Projection Chambers (TPCs). Here we report on the…
A new approach to suppress ion backflow in multi-GEM structures is suggested. In this approach, the potential difference applied across the gap between two adjacent GEMs is reversed compared to the standard configuration. In such a gap…
The operation of visible-sensitive gaseous- and, to some extent, vacuum-photomultipliers is critically affected by secondary electrons originating from ion impact on the photocathode. A simple method for indirect measurement of the…
One of the potential problems of a Micro-Pattern Gaseous Detector (MPGD)-based Time Projection Chamber (TPC) is the Ion back Flow (IBF): ions generated through the avalanche amplification process flow back to the drift volume of the TPC and…
A fundamental limit to the application of Time Projection Chambers (TPCs) in high-rate experiments is the accumulation of slowly drifting ions in the active gas volume, which compromises the homogeneity of the drift field and hence the…
We present results from our recent investigations on detectors comprising cascaded gas electron multipliers (GEM) and cascaded GEMs with micro-hole and strip (MHSP) electrodes. We discuss the factors governing the operation of these fast…
In recent years, compact nanodosimetric detectors based on ion multiplication in low-pressure gas have been developed and gained attention in the scientific community. These detectors use strong electric fields to collect and multiply…