Optimized Design of 8-Figure Null-Flux Coils in EDS Maglev.
The 8-figure null-flux ground coils in EDS (Electro-Dynamic Suspension) including the PLG (combined Propulsion, Levitation and Guidance) system, which can both suspend and propel maglev vehicles simultaneously, have mainly longitudinal and vertical dimensions such as coil pitch and heights of upper and lower coils. In this paper we investigate these dimensions not only to balance the basic performance for levitation, guidance and propulsion, but also to reduce magnetic disturbance of superconducting magnet. By using an optimization program, we induced the relationship between the basic performance and these dimensions. Furthermore, by implementing a modal analysis, we predicted the vibration of superconducting magnet in different pitches, and thereby proposed these dimensions to decrease the vibration.
Harmonic characteristics of SC coil configuration for EDS maglev to reduce leakage flux
An improved configuration of SC coils, whose end coils are small, is studied to reduce their leakage flux. This paper examines the harmonic characteristics when the improved configuration of SC coils is applied to the 120-degree coil pitch ground coil. An adequate combination of length and mmf in the end coils can provide proper performance of harmonics and basis. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 91(10): 20– 27, 2008; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/ecj.10163
Reduction of Surface Flashover of the Beam Screen of the LHC Injection Kickers
The LHC injection kicker magnets include beam screens to shield the ferrite yokes against wake fields resulting from the high intensity beam. The screening is provided by conductors lodged in the inner wall of a ceramic support tube. Operation with increasingly higher bunch intensity, and narrow bunches, now requires improved ferrite screening. This will be implemented by additional conductors; however the good high-voltage behaviour of the kicker magnets must not be compromised by the supplementary screening. Extensive studies and optimisations have been carried out, to better satisfy the often conflicting requirements for low beam coupling impedance, fast magnetic field rise-time, high vacuum and good high voltage behaviour. A new configuration is proposed which reduces significantly the electric field associated with the screen conductors and the secondary electron yield of the surface of the ceramic tube. Results of high voltage test results are also presented.