Results from a prototype beam monitor in the Tevatron using synchrotron light
A prototype synchrotron light monitor has been installed in the Tevatron at the downstream edge of a superconducting dipole magnet. Synchrotron light produced at the upstream edge of the magnet is sufficiently separated from the proton beam to be picked off by the monitor's mirror and diverted to its detector. It is shown that the way to enrich the low-wavelength region is to rely either upon short magnets (or an undulator which is a series of short magnets) or the sharp transition between the zero field region and the full-field region of a dipole magnet. The measured light intensity at different beam energies was compared to the predicted values. The parameters of a beam profile monitor are discussed.<<ETX>>
Performance of a beam monitor in the Fermilab Tevatron using synchrotron light
Synclite, the beam monitor in the Fermilab Tevatron using synchrotron light is described. The calibration, monitoring and performance of the system is discussed. Observation of some effects of long range beam-beam interactions seen in the beam monitor will be presented as well as a measurement of DC beam in the Tevatron.
Modeling Coherent Backscattering Errors in Fiber Optic Gyroscopes for Sources of Arbitrary Line Width
We present a new model of the noise and drift induced by coherent backscattering in a fiber optic gyroscope (FOG) interrogated with a light source of arbitrary temporal coherence. This study is critical to understand whether a FOG driven with a laser instead of a broadband source can attain high sensitivity and stability, which would have the overwhelming benefit of improving the FOG scale factor stability by at least ten-fold and would enable the use of FOGs for inertial navigation of aircrafts. Analytical and numerical solutions bring to light two significant new predictions. First, coherent-backscattering noise can be made negligibly small by utilizing a laser with a very narrow linewidth (less than ~ 20 kHz), although in this regime the drift is high. Second, by using a laser with a broad linewidth (greater than ~ 10 MHz), both the noise and the drift are low enough for aircraft inertial navigation. The dependencies of the noise and drift on fiber loss, loop coupling coefficient, and backscattering coefficient are also presented to define the optimum mode of operation of this new class of FOGs.