This paper introduces the design and simulation of a Wire Position Monitor （WPM） used in the cryogenic system of an Accelerator Driven System （ADS）. The WPM is designed to monitor the contraction of cold masses du...This paper introduces the design and simulation of a Wire Position Monitor （WPM） used in the cryogenic system of an Accelerator Driven System （ADS）. The WPM is designed to monitor the contraction of cold masses during the cooling-down operation. In this paper, POISSON-2D electrostatic field software is used to calculate the best characteristic impedance for the WPM. Furthermore, the time domain signal of different end structures is theoretically analyzed and simulated. The coupling of electrodes and the influence of signal carrier size, which may influence the induced signal, are also discussed. Finally, the linearity of the induced voltage and the sensitivity of the WPM are analyzed. The time domain simulation results are consistent with the theoretical analysis. The influences of the coupling and carrier size are very small, and the linearity of the normalized voltage is good within r/2.展开更多
A method to determine precisely three-dimensional wire positions in the BESⅢ drift chamber using physics events is introduced. In part the proposed technique takes advantage of the possibility that the magnetic field...A method to determine precisely three-dimensional wire positions in the BESⅢ drift chamber using physics events is introduced. In part the proposed technique takes advantage of the possibility that the magnetic field can be turned off, thereby providing a huge sample of straight tracks for which effects due to multiple scattering, energy loss and non-uniformity of the magnetic field are minimized during the calibration process. A toy Monte Carlo study is performed to demonstrate the viability of the method. As a result of the calibration process, the rms of the distribution of wire position deviation is reduced from 35 μm to 10 μm.展开更多
文摘This paper introduces the design and simulation of a Wire Position Monitor （WPM） used in the cryogenic system of an Accelerator Driven System （ADS）. The WPM is designed to monitor the contraction of cold masses during the cooling-down operation. In this paper, POISSON-2D electrostatic field software is used to calculate the best characteristic impedance for the WPM. Furthermore, the time domain signal of different end structures is theoretically analyzed and simulated. The coupling of electrodes and the influence of signal carrier size, which may influence the induced signal, are also discussed. Finally, the linearity of the induced voltage and the sensitivity of the WPM are analyzed. The time domain simulation results are consistent with the theoretical analysis. The influences of the coupling and carrier size are very small, and the linearity of the normalized voltage is good within r/2.
基金BEPCⅡ/BESⅢ Construction Project and Knowledge Innovation Project of Chinese Academy of Sciences(U-602,U-34(IHEP))
文摘A method to determine precisely three-dimensional wire positions in the BESⅢ drift chamber using physics events is introduced. In part the proposed technique takes advantage of the possibility that the magnetic field can be turned off, thereby providing a huge sample of straight tracks for which effects due to multiple scattering, energy loss and non-uniformity of the magnetic field are minimized during the calibration process. A toy Monte Carlo study is performed to demonstrate the viability of the method. As a result of the calibration process, the rms of the distribution of wire position deviation is reduced from 35 μm to 10 μm.
