LANL, Los Alamos, New Mexico
A beam position reproducibility measurement was performed using the beam position monitors in the Los Alamos Proton Storage Ring. The purpose of this measurement was to gain a better understanding of the quality, errors, and repeatability associated with such a measurement. Described here is a somewhat detailed understanding of how the beam position monitor measurement is made, and the procedure for this reproducibility experiment. Data and statistical analysis, and the fitting of the turn-by-turn position data are discussed in detail. Also reported are the errors found in the data acquisition, how often the errors occur, how the errors are identified and removed from the dataset, their effect on the quality of the beam position measurement, and scenarios of how these errors manifest in the data acquisition. The resulting conclusions of the repeatability of the beam position measurement is based on the spread of fitting parameters fit to the turn-by-turn beam position data.
BNL, Upton, Long Island, New York
Modes with transverse electric field (TE-modes) in the NSLS-II multipole vacuum chamber can be generated at frequencies above 450 MHz due to its geometric dimensions. Since the NSLS-II BPM system is triggered by the RF at 500 MHz, frequencies of higher-order modes (HOMs) can be generated within the transmission band of the band pass filter. In order to avoid systematic errors in the NSLS-II BPM system, we introduced frequency shift of HOMs by using RF metal shielding located in the antechamber slot.
BNL, Upton, Long Island, New York
The NSLS-II Light Source is being built at Brookhaven National Laboratory. It will provide users with ultimate brightness beam and the full realization of its capabilities requires corresponding stability of the beam orbit. The small aperture BPMs, located at the ends of a insertion device, will provide better sensitivity to the beam position but also requires thorough design. In this paper we present the results of the optimization including signal power levels and button heating.