Research on imaging detection of RF leakage on the surface of spacecraft
The determination and locating of leakage point is very important to shielding effect evaluation and solving EMC problem of spacecraft. A RF leakage detection method by near field scanning imaging is presented. The electromagnetic field distribution on the surface of spacecraft can be deduced from one on the plane at some distance to the surface of spacecraft with the convolution relation between electromagnetic field distributions on two parallel planes. The imaging of RF leakage point can be obtained by the method. The effect to imaging of measurement parameters is evaluated by simulation.
Near-field microwave imaging based on planar aperture scanning
A near-filed microwave imaging setup is investigated. The setup benefits from the high near-field directivity and good efficiency of a recently proposed ultra-wide band TEM horn antenna. The setup employs planar aperture scanning. It consists of two antennas aligned along each other's boresight and moving together to scan two parallel apertures. The imaged object lies between the two apertures. With a blind de-convolution algorithm, the images are de-blurred. Simulation and experimental results confirm the satisfactory performance of this setup for near-field microwave imaging with possible application in breast cancer diagnosis.
Parameters for low energy operation of CESR
We present a detailed design for operation of the Cornell Electron Storage Ring, CESR, in the energy range covering the /spl psi/ resonances and the Charm and Tau thresholds, as well as reaching to the upper Y resonances near 11 GeV. The addition of 18 m of super-ferric wiggler magnets will partially restore low energy beam emittance and damping times. Installation of superconducting quadrupoles in the interaction region and the addition of high performance superconducting RF cavities will enhance performance at all energies. Studies of optics, beam dynamics, wiggler and vacuum system performance, beam stability, and beam-beam effects confirm operation with a luminosity of 3/spl times/ 10/sup 32/ CM/sup -2/ sec/sup -1/ at 1.88 GeV.