Diamond Beam-Position Monitor for Undulator Radiation and Tests at the Tristan Super Light Facility

A photon beam-position monitor using a diamond foil as a position-sensitive device has been developed for use on insertion-device beamlines of third-generation synchrotron radiation facilities such as SPring-8, and was tested on the undulator beamline of the Tristan Super Light Facility at KEK. The beam test results show that the diamond monitor can be operated in a photoconductive mode like a semiconductor detector. It has a linear working range of about ±1 mm and a position sensitivity of less than 3 μm. The stability of the monitor was confirmed by continuous operation under low photon beam intensity conditions.