arXiv subjects

X Wang

Publications and source records attributed to X Wang.

5 recordsLinked to original sources

arXiv2022

CEE inner TOF prototype design and preliminary test results

The Cooling Storage Ring (CSR) External-target Experiment(CEE) is the first multi-purpose nuclear physics experimental device to operate in the GeV energy range at the Heavy-Ion Research Facility(HIRFL-CSR) in Lanzhou, China. The primary goals of the CEE are to study the bulk properties of dense matter and to understand the quantum chromo-dynamic (QCD) phase diagram by measuring the charged particles produced in heavy-ion collisions at the target region with a large acceptance. An inner time of flight (iTOF) system has been proposed to measure the multiplicity, angular distribution, and time information of the charged particles. Herein, we introduce the performance requirements of iTOF according to calculations and GEANT4 simulations. The proposed system is characterized by high granularity and time performance, hence, the conceptual design of the iTOF wall adopts high granularity Multi-gap Resistive Plate Chambers (MRPC) with a time resolution of around 30 ps. To evaluate the MRPC design, the cosmic ray test was performed. A timing resolution better than 28 ps and an efficiency better than 98% has been achieved for MIPs, as interpreted by the cosmic ray GEANT4 simulation of time jitter components.

physics.ins-det↗

arXiv2019

Topological background discrimination in the PandaX-III neutrinoless double beta decay experiment

The PandaX-III experiment plans to search for neutrinoless double beta decay (0$νββ$) of $^{136}$Xe in the China JinPing underground Laboratory (CJPL). The experiment will use a high pressure gaseous Time Projection Chamber (TPC) to register both the energy and the electron track topology of an event. This article is devoted to the software side of the experiment. As software tool we use REST, a framework developed for the reconstruction and simulation of TPC-based detector systems. We study the potential for background reduction by introducing appropiate parameters based on the properties of 0$νββ$ events. We exploit for the first time not only the energy density of the electron track-ends, but also the electron scattering angles produced by an electron near the end of its trajectory. To implement this, we have added new algorithms for detector signal and track processing inside REST. Their assessment shows that background can be reduced by about 7 orders of magnitude while keeping 0$νββ$ efficiency above 20% for the PandaX-III baseline readout scheme, a 2-dimensional 3mm-pitch stripped readout. More generally, we use the potential of REST to handle 2D/3D data to assess the impact on signal-to-background significance at different detector granularities, and to validate the PandaX-III baseline choice. Finally, we demonstrate the potential to discriminate surface background events generated at the readout plane in the absence of $t_o$, by making use of event parameters related with the diffusion of electrons.

physics.ins-det↗

arXiv2018

MRPC3b mass production for CBM-TOF and eTOF at STAR

The Compressed Baryonic Matter (CBM) spectrometer aims to study strongly interacting matter under extreme conditions. The key element providing hadron identification at incident energies between 2 and 11 AGeV in heavy-ion collisions at the SIS100 accelerator is a Time-of-Flight (TOF) wall covering the polar angular range from $2.5^0$ --$25^0$ and full azimuth. CBM is expected to be operational in the year 2024 at the Facility for Anti-proton and Ion Research (FAIR) in Darmstadt, Germany. The existing conceptual design foresees a 120 m^2 TOF-wall composed of Multi-gap Resistive Plate Chambers (MRPC) which is subdivided into a high rate region, a middle rate region and a low rate region. The MRPC3b Multistrip-MRPCs, foreseen to be integrated in the low rate region, have to cope with charged particle fluxes up to 1 kHz/cm2 and therefore will be constructed with thin float glass (0.28 mm thickness) as resistive electrode material. In the scope of the FAIR phase 0 program it is planned to install about 36 \% of the MRPC3b counters in the east endcap region of the STAR experiment at BNL as an upgrade for the Beam Energy Scan campaign (BESII) in 2019/2020.

physics.ins-det↗

arXiv2010

An extended hybrid magnetohydrodynamics gyrokinetic model for numerical simulation of shear Alfvén waves in burning plasmas

Adopting the theoretical framework for the generalized fishbonelike dispersion relation, an extended hybrid magnetohydrodynamics gyrokinetic simulation model has been derived analytically by taking into account both thermal ion compressibility and diamagnetic effects in addition to energetic particle kinetic behaviors. The extended model has been used for implementing an eXtended version of Hybrid Magnetohydrodynamics Gyrokinetic Code (XHMGC) to study thermal ion kinetic effects on Alfvénic modes driven by energetic particles, such as kinetic beta induced Alfvén eigenmodes in tokamak fusion plasmas.

physics.plasm-ph↗

arXiv2010

Thin-film-like high temperature superconducting $\mathrm{Bi_2Sr_2CaCu_2O_{8+}}{_x}$ single crystal by mechanical exfoliation

Thin-film-like high temperature superconducting Bi2Sr2CaCu2O8+x single crystals (TSB) with a typical thickness of 20-200 nm is produced by mechanical exfoliation. The TSB, which shows excellent superconductivity, can adhere firmly to the substrate by van der Waals force. The TSB may find important applications in fabricating high temperature superconducting devices. Intrinsic Josephson junctions made of the TSB are demonstrated. A very interesting finding is that the TSB can follow exactly the topology of the substrate, making it possible to fabricate superconducting devices with artificial structures by using substrate template, for instance, step-edge Josephson junctions.

cond-mat.supr-con↗