《Survey amp; Alignment of Pohang Light Source》.pdfVIP

I / 6 7 Survey Alignment of Pohang Light Source Ae-Hee Maeng, Kwang-Won Seo and Seung-Chan Lee Pohang Accelerator Laboratory POSTECH, Pohang, Kyungbuk 790-784, KOREA A B S T R A C T Pohang Light Source(PLS) which is operated by Pohang Accelerato r Laboratory(PAL) of Pohang University of Science and Technology(POSTECH) is the third generation synchrotron radiation source. The project was initiated in April 1988, and completed in December 1994. As a method to achieve the required positional accuracy of a few tenths of a millimeter for the PLS machines, we have introduced various precision surveying instruments and techniques. For linac alignment, we applied an optical tooling technique to a prealignment process, and developed a laser alignment system of a He-Ne laser and Fresnel zone plates for final alignment in the accelerator tunnel. We introduced a noncontact 3-dimensional measuring system with theodolites , conventional surveying technique with survey network for storage ring alignment, and a GEONET program for data analysis and database management. A smoothing analysis using a low-path filtering method was developed for estimating the electron beam orbit and offset error of the magnets in the storage ring. The positional errors of 0.