arXiv subjects

Sunidhi Saxena

Publications and source records attributed to Sunidhi Saxena.

5 recordsLinked to original sources

arXiv2026

Effect of hole pitch reduction on electron transport and diffusion: A comparative simulation study of Triple GEM detectors

Advances in fabrication techniques and high-performance electronics have facilitated the development of fine-pitch Gas Electron Multipliers (GEMs). Earlier experimental and simulation findings suggest that these reduced-pitch GEMs can outperform the standard configuration in terms of effective gain, collection efficiency, and position resolution. However, a noticeable fraction of avalanche electrons is lost within the GEM systems, resulting in a degradation of charge collection efficiency. Therefore, a comprehensive simulation-based study is essential to provide deeper insights into the extent of degradation and its contributing factors. In this context, we employ ANSYS and Garfield++ to model the Triple GEM detectors with reduced pitch sizes of 90 and 60 $μ$m, and perform a comparative performance analysis with the standard configuration (pitch size: 140 $μ$m). At first, the simulation framework is validated by comparing the results of the standard configuration with available experimental data and previously reported simulation outcomes. Despite the characteristic gain offset, the framework remains physically consistent and reliable in capturing microscopic avalanche dynamics, reproducing the experimental trend. Following validation, we investigate electron losses at the metal electrodes and within the Kapton holes, electron transmission through the transfer and induction regions, electron diffusion on the induction electrode, and the overall collection efficiency. These parameters are analyzed as functions of GEM potential, outer hole diameter, inner hole diameter, Kapton thickness, metal thickness, and gas composition, thereby offering insights for designing efficient GEM detectors.

physics.ins-det↗

arXiv2025

Investigating the effects of acceptor removal mechanism and impact ionization on proton irradiated 300 $μ$m thick LGAD

Low-Gain Avalanche Detectors (LGADs) are the leading 4D sensing technology selected for use in the High Luminosity Large Hadron Collider (HL-LHC). However, their proximity to the interaction point makes them highly susceptible to radiation-induced damage. Such degradation effects can be effectively studied through TCAD simulations. In this work, we extend the validation of a previously developed proton damage model for transitional sensors. The enhanced model for LGAD also incorporates an acceptor removal mechanism and modifications in impact ionization behavior, resulting in a more comprehensive and reliable tool for fabrication and performance analysis.

physics.ins-det↗

arXiv2025

Study of anisotropic flow of heavy hadrons in Au + Au collisions at $\sqrt{s_{NN}} =$ 200 GeV using HYDJET++ framework

A comprehensive study of the anisotropic flow of heavy hadrons ($D^{0}$, $D^{\pm}$, and $Λ_{c}$) in Au + Au collisions at $\sqrt{s_{NN}} = 200$ GeV using the HYDJET++ model is presented. This study aims to explore the collective behavior and thermalization of charm hadrons at RHIC energy. The modeling of anisotropic flow is performed using a centrality-dependent parameterization of anisotropic parameters. Our model results are consistent with STAR experimental results up to $p_{T} = 4$ GeV/c. It captures the centrality-dependent shifts of the flow peak towards lower $p_{T}$ as collisions become more peripheral. This shift is attributed to the weaker radial flow in peripheral collisions. The model also reproduces important features such as the number-of-constituent-quark scaling, mass ordering, and baryon-meson grouping, all consistent with experimental observations. Furthermore, we present comparisons with other models, like DUKE, SUBATECH, TAMU, and AMPT. Overall, our results highlight the efficacy of HYDJET++ in describing the collective dynamics of heavy-flavor hadrons in the quark-gluon plasma medium.

hep-ph↗

arXiv2025

Study of Heavy Hadron Production in Au + Au Collisions at a Center-of-Mass Energy of $\sqrt{s_{NN}}=200$ GeV

Using the Monte Carlo HYDJET++ model, the transverse momentum ($p_{T}$) spectra of heavy hadrons ($D^{0}$, $\overline{D}^{0}$, $D^{+}$, $D^{-}$ and $Λ_{c}$), as well as the nuclear modification factors of $D^{0}$ and $D^{\pm}$, produced in Au + Au collisions at $\sqrt{s_{NN}} = 200$ GeV RHIC energy across various centrality bins, are presented. This study is motivated by the need to understand the centrality dependence of the charm enhancement factor ($γ_{c}$) and the roles of different hadronization mechanisms such as coalescence and fragmentation, in charm hadron production. To achieve the best description of heavy hadron production, several input parameters in both the soft and hard components of the model are tuned. The study finds a decreasing trend of $γ_{c}$ from central to peripheral collisions and a mass dependence across charm hadrons. Moreover, the model effectively reproduces experimental data of $p_{T}$ spectra at low and intermediate $p_{T}$, capturing key features of charm hadron production in the quark-gluon plasma medium. However, it overpredicts the data at high $p_{T}$, indicating the need for improvements in modeling heavy quark energy loss mechanisms. Further, the nuclear modification factors ($R_{AA}$ and $R_{CP}$) for $D^{0}$ mesons exhibit significant suppression in central collisions, which matches with experimental observations. This highlights the roles of collisional and radiative energy loss due to collective effects, such as coalescence and radial flow. The antiparticle-to-particle and mixed particle ratios are also presented, showing good agreement with experimental data and revealing limitations in baryon production due to the absence of heavy quark coalescence in HYDJET++.

hep-ph↗

arXiv2025

Simulation-based performance comparison of varied pitch sizes GEM detectors

Gas Electron Multiplier (GEM) detectors, typically featuring a standard pitch size of 140 $μ$m and an inner hole diameter of 50 $μ$m, are extensively utilized in high-energy physics experiments for tracking, triggering, and timing measurements. Their characteristics, such as high gain, good position resolution, improved temporal resolution, low discharge probability, radiation hardness, and high rate capabilities, make them highly favoured. Recent experimental studies have shown that triple-GEM detectors with a reduced pitch size of 90 $μ$m and a smaller hole diameter of 40 $μ$m can perform better than standard-pitch GEM detectors. To assess the effectiveness of these reduced dimensions, we conducted a simulation-based study using ANSYS and Garfield++. As a first step, we validated the simulation framework by modelling a standard single GEM detector and comparing the results with previous simulations and experimental data. Following validation, we designed GEM structures with reduced pitch sizes of 90 $μ$m and 60 $μ$m. We then performed a comparative analysis, focusing on key performance parameters like effective gain, electron transparency, and position resolution. These parameters were varied against an increase in GEM potential, drift electric field, induction electric field, drift gap, induction gap, and gas composition to optimize the performance of the detectors.

hep-ex↗