Purpose: Small-angle Bhabha scattering of e+e- → e+e-(nγ) has a very large cross-section and is a favorable process for measuring e+e- collision luminosity. The theoretical precision is approaching 10-4. The experimental measurements of radiative Bhabha interactions have been achieved at the 1 % level. We present Monte Carlo simulations using BHLUMI and BHWIDE programs to estimate the...
In order to ensure measurement of the integrated luminosity with a relative precision of 10−4 at the Z0 pole at CEPC, numerous systematic effects have to be quantified and corrected for. Here we discuss collective impact of electromagnetic bunch fields on the initial state electrons and positrons as well as on the final states produced in Bhabha scattering. These effects change four-momenta of...
The Circular Electron Positron Collider (CEPC) requires a fast luminosity detector to achieve a relative measurement precision of 2% at a sampling rate of 1 kHz in order to drive a real-time orbit feedback system, due to its extremely high luminosity. 4H-SiC, with its wide bandgap, high displacement threshold energy, and high saturated electron drift velocity, simultaneously offers excellent...
This work focuses on the development of cold plate components for the CEPC detector. An ultra-light carbon fiber composite unidirectional heat conductive cold plate was manufactured by hot-pressing carbon fiber and graphene, and its thermal conductivity was optimized. The resulting cold plate exhibits a density lower than that of aluminum and a thermal conductivity higher than that of...
An harmonious calorimeter idea has been proposed. We designed a new structure of ECAL and HCAL. More detailed structure information will be introduced in this report. A new cooling scheme has been proposed and test also has been carried out.
The contents include:
1.Current research status of beam pipes at home and abroad.
2.Background introduction of the CEPC central beam pipe.
3.Structural design of the central beam pipe.
4.Simulation of heat dissipation for the central beam pipe.
5.Progress in fabrication of experimental specimens for the central beam pipe.
6.Implementation of subsequent heat dissipation experiments on the...
preliminary air cooling test results of the VTX thermal mockups .
The inner vertex detector of the IDEA detector concept is based on MAPS technology, and is expected to dissipate less than about 50 mW/cm2. With such low power density air-cooling solutions can be developed. Two main mechanical arrangements for the silicon sensors are envisaged at the moment:a ‘traditional’ flat version, in which MAPS are put on top of a carbon fibre stave, and a curved sensor...
The machine-detector interface (MDI) issues are one of the most complicate and challenging topics at the Circular Electron Positron Collider (CEPC). Comprehensive understandings of the MDI issues are decisive for achieving the optimal overall performance of the accelerator and detector. The machine will operate at different beam energies, therefore, a flexible interaction region design will be...
In recent years, several next‑generation large‑scale scientific facility plans based on electron‑positron colliders have been successively launched in the field of international high‑energy physics (FCCee, CEPC, ILC, etc.). In the published conceptual designs of accelerators and detectors, the Time Projection Chamber (TPC) is widely selected as the main tracking detector owing to its unique...
This talk will present the latest status of Zero Degree Calorimeter at BESIII. The structure of ZDC is inspired by the CEPC LumiCal which is made of Lyso crystal and SiPM.
Its primary goal is to measure the instantaneous luminosity of BEPCII and can be extended to tag the ISR photon.
The developing progress of the CEPC detector magnet is introduced in the report, including the Box-type aluminum stablized NbTi Rutherford cable and HTS cable.
