LBNL, Berkeley, California
Stabilized optical fiber links have been under development for several years for high precision transmission of timing signals for remote synchronization of accelerator and laser systems. In our approach, a master clock signal is modulated on an optical carrier over a fiber link. The optical carrier is also used as the reference in a heterodyne interferometer, which is used to precisely measure variations, mainly thermal, in the fiber length. The measured variations are used to correct the phase of the transmitted clock signal. We present experimental results showing sub-10 fsec relative stability of a 200 m link, and sub-20 fsec stability of a 2.2 km link.
UMD, College Park, Maryland
MPI-K, Heidelberg
Cockcroft Institute, Warrington, Cheshire
We have developed a technique that employs a digital micro-mirror array to produce an image of the halo of an electron beam with enhanced dynamic range. Light produced by the beam intercepting a phosphor screen is first imaged onto the array; an adaptive mask is created and applied to filter out the beam core; and the result is reimaged onto an intensified CCD camera. We describe the optics used, the masking operation and preliminary results of experiments we have performed to study beam halo at the University of Maryland Electron Ring (UMER).
