At the CEPC （Circular Electron Positron Collider）, which is proposed by the Chinese high energy physics community, the dominant background comes from radiative Bhabha scattering and the beamstrahlung effect accordin...At the CEPC （Circular Electron Positron Collider）, which is proposed by the Chinese high energy physics community, the dominant background comes from radiative Bhabha scattering and the beamstrahlung effect according to preliminary research. Therefore, it is necessary to incorporate a collimator system to intercept particles that may be lost near the interaction region （IR）. In this paper, we introduce some limitations in choosing the position and width of the collimators. A certain parameter range is determined which is confined by the β function and the width of the collimators. A suitable choice of the half width is made by exploring this parameter range. A simulation of the particle loss rate in the IR and the hit density in the vertex detector with and without the collimators shows that the set of parameters of the collimators we designed is appropriate and effective.展开更多
The discovery of a 125 GeV Higgs boson at the LHC marked a breakthrough in particle physics. The relative lightness of the new particle has inspired consideration of a high-luminosity Circular Electron positron Collid...The discovery of a 125 GeV Higgs boson at the LHC marked a breakthrough in particle physics. The relative lightness of the new particle has inspired consideration of a high-luminosity Circular Electron positron Collider （CEPC） as a Higgs Factory to study the particle＇s properties in an extremely clean environment. Given the high luminosity and high energy of the CEPC, beamstrahlung is one of the most important sources of beam- induced background that might degrade the detector performance. It can introduce even more background to the detector through the consequent electron-positron pair production and hadronic event generation. In this paper, beamstrahlung-induced backgrounds are estimated with both analytical methods and Monte Carlo simulation. Hit density due to detector backgrounds at the first vertex detector layer is found to be -0.2 hits/cm2 per bunch crossing, resulting in a low detector occupancy below 0.5%. Non-ionizing energy loss （NIEL） and total ionizing dose （TID）, representing the radiation damage effects, are estimated to be -1011 1 MeV neq/cm2/yr and --300 kRad/yr, respectively.展开更多
文摘At the CEPC （Circular Electron Positron Collider）, which is proposed by the Chinese high energy physics community, the dominant background comes from radiative Bhabha scattering and the beamstrahlung effect according to preliminary research. Therefore, it is necessary to incorporate a collimator system to intercept particles that may be lost near the interaction region （IR）. In this paper, we introduce some limitations in choosing the position and width of the collimators. A certain parameter range is determined which is confined by the β function and the width of the collimators. A suitable choice of the half width is made by exploring this parameter range. A simulation of the particle loss rate in the IR and the hit density in the vertex detector with and without the collimators shows that the set of parameters of the collimators we designed is appropriate and effective.
基金Supported by CAS/SAFEA International Partnership Program for Creative Research TeamsCAS and IHEP Thousand Talent and Hundred Talent programsgrants from the State Key Laboratory of Nuclear Electronics and Particle Detectors
文摘The discovery of a 125 GeV Higgs boson at the LHC marked a breakthrough in particle physics. The relative lightness of the new particle has inspired consideration of a high-luminosity Circular Electron positron Collider （CEPC） as a Higgs Factory to study the particle＇s properties in an extremely clean environment. Given the high luminosity and high energy of the CEPC, beamstrahlung is one of the most important sources of beam- induced background that might degrade the detector performance. It can introduce even more background to the detector through the consequent electron-positron pair production and hadronic event generation. In this paper, beamstrahlung-induced backgrounds are estimated with both analytical methods and Monte Carlo simulation. Hit density due to detector backgrounds at the first vertex detector layer is found to be -0.2 hits/cm2 per bunch crossing, resulting in a low detector occupancy below 0.5%. Non-ionizing energy loss （NIEL） and total ionizing dose （TID）, representing the radiation damage effects, are estimated to be -1011 1 MeV neq/cm2/yr and --300 kRad/yr, respectively.
