Integrating log-ratio position processing for the Los Alamos Proton Storage Ring extraction line

The Los Alamos Proton Storage Ring (PSR) is a compressor ring intended to accept 1-msec-long proton macropulses from the LAMPF linear accelerator and compress these pulses to 250 nsec in length. Beam position monitor sensors of the terminated strip-line design centered at 200 MHz are provided in the transport line from LAMPF, the PSR injection line, the PSR ring, and the extracted beam line. Strip-line sensors used in conjunction with phase processing are a good match for linac transport lines and PSR injection lines where there exists a strong 200-MHz frequency component but lead to difficulties in the ring and extracted beam line where this component tends to wash out. This paper describes the development of Integrating Log-Ratio processing techniques, which utilize the original strip line sensors to achieve a major improvement in position monitoring for the extracted beam line. The design concepts are discussed and the present hardware is described in detail. Operational difficulties encountered during the development process are discussed and actual beam-related results are provided