New electrostatic pick-ups for the PS

This paper, as part of the adaptation of the PS to the acceleration of electron and positron beams for LEP, reports on the development of electrostatic pick-ups for the closed orbit measurement. An all metallic design of interlaced electrodes has been adopted to satisfy the stringent requirements of the new vacuum system. The careful layout of the signal pick-off on each of the four electrodes as well as the use of a special hybrid coupler were essential to cover the large frequency spectrum associated with the acceleration or deceleration of p, p, d or e ± beams. The sensitivity of the system can be controlled over a range of 66 dB fast enough to follow the pulse-to-pulse modulation (ppm) operation of the PS