Narrow Results

With the discovery of the Higgs boson at around 125 GeV, a circular Higgs factory design with high luminosity $(L\sim 10^{34}{\mathrm{\text{cm}}}^{-2}{\mathrm{\text{s}}}^{-1})$ is becoming more popular in the accelerator world. The CEPC project in China is one of them. Machine Detector Interface (MDI) is the key research area in electron–positron colliders, especially in CEPC; it is one of the criteria to measure the accelerator and detector design performance. Because of the limited space available in the designed tunnel, many equipment including magnets, beam diagnostic instruments, masks, vacuum pumps, and components of the detector must coexist in a very small region. In this paper, some important MDI issues will be reported for the Interaction Region (IR) design, e.g. the final doublet quadrupoles physics design parameters, beam-stay-clear region and beam pipe, synchrotron radiation power and critical energy are also calculated.

With the discovery of the Higgs boson at around 125 GeV, a circular Higgs factory design with high luminosity $(L\sim 10^{34}{\mathrm{\text{cm}}}^{-2}{\mathrm{\text{s}}}^{-1})$ is becoming more popular in the accelerator world. The Circular Electron and Positron Collider (CEPC) project in China is one of them. Machine Detector Interface (MDI) is the key research area in electron–positron colliders, especially in CEPC. Since the $e^{+}{e}^{-}$ beams collide at the Interaction Point (IP) with a horizontal angle of 33 mrad, the horizontal trajectory will couple to the vertical. Due to the solenoid and anti-solenoid combined field strength quite high, the maximum could be up to 4.2 T, the transverse magnetic field component is also quite high. Thus synchrotron radiation (SR) from vertical trajectory in combined field should be taken into account. And also synchrotron radiation is an important influential factor in the collimator design of CEPC MDI. These two effects are analyzed in this paper.

With the discovery of the Higgs boson at around 125 GeV, a circular Higgs factory design with high luminosity ($L\sim 10^{34} {\mathrm{\text{cm}}}^{-2} {\text{s}}^{-1}$) is becoming more popular in the accelerator world. The CEPC project in China is one of them. Machine Detector Interface (MDI) is the key research area in electron–positron colliders, especially in CEPC, since the synchrotron radiation (SR) photons can contribute to the heat load of the beam pipe and radiation dose may damage the components. And the heat load can cause the temperature rise in some part, and if the temperature rise is too high, the beryllium pipe in the interaction region will melt and the superconducting magnet may quench. Thus, the heat load distribution from synchrotron radiation and beam loss in the interaction region are analyzed carefully and results are given in this paper.

The Circular Electron Positron Collider (CEPC) is a proposed Higgs factory with center-of-mass energy of 240GeV to measure the properties of Higgs boson and test the standard model accurately. Synchrotron radiation (SR) generated from the final doublet (FD) magnets in the interaction region of CEPC double ring scheme is one of the typical issues. SR photons can contribute to the heat load of the beam pipe and cause photon background to the experiments. Furthermore, the radiation dose can damage detector components. In this paper, SR generated from FD magnets is analyzed when beam is with tails and offset. SR from the dipole leakage field of the FD superconducting magnets is also analyzed and the physics limit is given to protect the detector.

The Circular Electron Positron Collider (CEPC) is a proposed Higgs factory with center-of-mass energy of 240GeV to measure the properties of Higgs boson and test the standard model accurately. Beam loss background in detectors is an important topic at CEPC. During manufacture and installation, magnets are not perfect and with many kinds of errors. Beam–beam interaction in high-energy electron positron collider is the action of external field force, which changes the momentum of each beam bunch. Thus, beam loss background can be affected by the magnet errors and beam–beam effect. In this paper, the beam loss background with magnet errors and beam–beam effect is simulated in CEPC.

We examine the relative institutional failure risks for three sets of bank depositories: Community Development Banking Institutions (CDBIs), Minority Depositories (MDIs) and what we term Non-Mission Depository Institutions (NMDIs). CDBIs have primary missions of community development and serving underserved populations; MDIs are typically led by minorities and serve minority populations (a single institution can be both a CDBI and an MDI, either or neither). In this analysis, NMDIs represent all other depository banks. Given their operation within lower-income and minority communities, MDIs and CDBIs appear, prima facie, to face greater institutional failure risks. We examine these risks across each set of institutions, ceteris paribus. Utilizing data from a number of sources, including the Reports of Condition and Income (call reports) for a substantial set of FDIC-insured banks in the United States, we apply a modified Capital, Assets, Management, Earnings and Liquidity model (CAMEL) to measure the predictive likelihood of failure. Recognizing that MDIs are not homogeneous, we also examine relative institutional failure across types of depositories. The results indicate that CDBIs and MDIs are systematically at lower failure risks and that there are differences across service designations.