arXiv subjects

Serguei Ganjour

Publications and source records attributed to Serguei Ganjour.

6 recordsLinked to original sources

arXiv2022

Double-hit separation and dE/dx resolution of a time projection chamber with GEM readout

A time projection chamber (TPC) with micropattern gaseous detector (MPGD) readout is investigated as main tracking device of the International Large Detector (ILD) concept at the planned International Linear Collider (ILC). A prototype TPC equipped with a triple gas electron multiplier (GEM) readout has been built and operated in an electron test beam. The TPC was placed in a 1 T solenoidal field at the DESY II Test Beam Facility, which provides an electron beam up to 6 GeV/c. The performance of the readout modules, in particular the spatial point resolution, is determined and compared to earlier tests. New studies are presented with first results on the separation of close-by tracks and the capability of the system to measure the specific energy loss dE/dx. This is complemented by a simulation study on the optimization of the readout granularity to improve particle identification by dE/dx.

physics.ins-det↗

arXiv2020

Numerical study of track distortion in the Large Prototype TPC with end-plate based on bulk Micromegas

The present $\mathrm{R}\&\mathrm{D}$ activities for the International Large Detector Time Projection Chamber (ILD-TPC) concern the adoption of the micro pattern devices for the gaseous amplification stage. Seven Micromegas modules which are commissioned on the end-plate of a Large Prototype TPC (LPTPC) at DESY, were tested with a 5 GeV electron beam, under a 1 T magnetic field. During experiments, reduced signal sensitivity as well as distortion in the reconstructed track was observed at the boundaries of these modules. Electrostatic field inhomogeneity near the module boundaries was considered to be the possible major reason behind these observations. In the present work, this hypothesis has been explored using the Garfield simulation framework. It has been possible to contain the computational complexity of the problem with suitable simplifications. Qualitative and quantitative agreements with experimental results have been achieved. Possibility of mitigating the problems has been proposed using the same simulation framework.

physics.ins-det↗

arXiv2017

Measurement and simulation of two-phase CO$_2$ cooling for the AFTER electronics of the Micromegas modules for a Large Prototype of a Time Projection Chamber

The readout electronics of a Micromegas (MM) module consume nearly 26 W of electric power, which causes the temperature of electronic board to increase upto $70\,^{\circ}{\rm C}$. Increase in temperature results in damage of electronics. Development of temperature gradient in the Time Projection Chamber (TPC) may affect precise measurement as well. Two-phase CO$_2$ cooling has been applied to remove heat from the MM modules during two test beam experiments at DESY, Hamburg. Following the experimental procedure, a comprehensive study of the cooling technique has been accomplished for a single MM module by means of numerical simulation. This paper is focused to discuss the application of two-phase CO$_2$ cooling to keep the temperature below $30\,^{\circ}{\rm C}$ and stabilized within $0.2\,^{\circ}{\rm C}$.

physics.ins-det↗

arXiv2017

Experimental and numerical simulation of a TPC like set up for the measurement of ion backflow

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 effective and can help the TPC drift volume to remain relatively free of space charge build-up. An efficient and precise measurement of the backflow fraction is necessary to cope up with the track distortion due to the space charge effect. In a subtle but significant modification of the usual approach, we have made use of two drift meshes in order to measure the ion backflow fraction for bulk Micromegas detector. This helps to truly represent the backflow fraction for a TPC. Moreover, attempt is taken to optimize the field configuration between the drift meshes. In conjunction with the experimental measurement, Garfield simulation framework has been used to simulate the related physics processes numerically.

physics.ins-det↗

arXiv2016

A Time Projection Chamber with GEM-Based Readout

For the International Large Detector concept at the planned International Linear Collider, the use of time projection chambers (TPC) with micro-pattern gas detector readout as the main tracking detector is investigated. In this paper, results from a prototype TPC, placed in a 1 T solenoidal field and read out with three independent GEM-based readout modules, are reported. The TPC was exposed to a 6 GeV electron beam at the DESY II synchrotron. The efficiency for reconstructing hits, the measurement of the drift velocity, the space point resolution and the control of field inhomogeneities are presented.

physics.ins-det↗

arXiv2008

Inclusive Search for the SM Higgs Boson in the H->gammagamma channel at the LHC

A prospective for the inclusive search of the Standard Model Higgs boson in the decay channel H->gammagamm is presented with the CMS experiment at the LHC. The analysis relies on a strategy to determine the background characteristics and systematics from data. The strategy is applied to a Monte Model of the QCD background, with full simulation of the detector response. The discrimination between signal and background exploits information on photon isolation and kinematics. The resolution for the reconstructed Higgs boson mass profits from the excellent energy resolution of the CMS crystal calorimeter. A discovery significance above 5 sigma is expected at integrated LHC luminosities below 30 inverse femtobarn for Higgs boson masses below 140 GeV/c^2.

hep-ex↗