Product Code: ICAL08_1707

Laser Welding of Copper Alloy for Beam Monitor System
Authors:
Zhiyue Xu, Argonne National Laboratory; Argonne IL USA
James W. Morgan, Argonne National Laboratory; Argonne USA
Keng H Leong, Argonne National Laboratory; Argonne IL USA
James L. Bailey, Argonne National Laboratory; Argonne USA
Presented at ICALEO 2008

Beam position monitors (BPM) are critical for beam-based alignment and operation of the worlds first X-ray free electron laser, Linac Coherent Light Source, being built at Stanford Linear Accelerator Center. Fabrication of the BPMs requires welding of components made of copper alloy that is extremely difficult to weld due to its low absorptivity to laser light and a high thermal conductivity. This paper presents a laser welding technique for jointing the BPM components. In this technique, a surface coating and a set of pulsed laser process parameters were developed to enhance the absorption to the laser beam and to produce sound cylindrical butt welds. Results from a welding monitor used to real-time monitor the process for weld quality control are also reported.