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Qinglei Xiu

Publications and source records attributed to Qinglei Xiu.

3 recordsLinked to original sources

Design, Fabrication and Characterization of Microwave Multiplexing SQUID Prototype

The readout system with a high multiplexing ratio has become a bottleneck limiting the application of large-scale Transition Edge Sensor (TES) detector arrays. In recent years, the microwave superconducting quantum interference device (SQUID) multiplexer has emerged as a key technology for effectively reading large-scale cryogenic detector arrays. Currently, the microwave SQUID multiplexer is being adopted by an increasing number of experiments due to its capability of achieving a multiplexing ratio of 2000:1 within the readout bandwidth. In this study, we developed and fabricated a 32-channel microwave SQUID multiplexer prototype. And we measured 8 channels of the prototype. The measured equivalent noise current of the prototype reached 42 pA/$\sqrt{Hz}$.

physics.ins-det

Study of the Tracking Method and Expected Performance of the Silicon Pixel Inner Tracker Applied in BESIII

The inner drift chamber of the BESIII is encountering serious aging problem after five year's running. For the first layer, the decrease in gas gain is about 26% from 2009 to 2013. The upgrade of the inner tracking detector has become an urgent problem for the BESIII experiment. An inner tracker using CMOS pixel sensors is an important candidate because of its great advantages on spatial resolution and radiation hardness. In order to carry out a Monte Carlo study on the expected performance, a Geant4-based full simulation for the silicon pixel detector has been implemented. The tracking method combining the silicon pixel inner tracker and outer drift chamber has been studied and a preliminary reconstruction software was developed. The Monte Carlo study shows that the performances including momentum resolution, vertex resolution and the tracking efficiency are significantly improved due to the good spatial resolution and moderate material budget of the silicon pixel detector.

physics.ins-det

Study of the Beamstrahlung Effects at the CEPC

The discovery of a 125 GeV Higgs boson at the LHC marked a breakthrough in particle physics. The relative lightness of the new particle inspires the consideration of a high luminosity Circular Electron Positron Collider (CEPC) as a Higgs Factory to study the Higgs boson in a clean environment. At the CEPC, the beamstrahlung might represent one of the most important sources of beam-induced backgrounds that will impact the detector. It will introduce additional backgrounds to the CEPC detector through the subsequent electron-positron pair production and the hadronic process. Therefore its impacts should be carefully evaluated. In this paper, the beamstrahlung-induced backgrounds are first estimated with analytical methods and are further evaluated in detail with Monte Carlo simulation. The detector occupancy due to the beamstrahlung at the location where the first vertex detector layer may be placed is found to be well below 0.5%. Radiation levels characterised as non-ionising energy loss (NIEL) and total ionising dose (TID) are estimated to be ~ $10^{11} 1 $ MeV $ n_{eq}/cm^2/$yr and ~ 300 kRad/yr, respectively.

physics.acc-ph