Ultra-precision machining and its application to advanced accelerators (4)

Ultra-precision machine was constructed for machining the cells of X-band accelerating tube in the constant temperature room. The surface of cell is smoothed by argon beam using the Elastic Emission Machining (EEM) method. New junction method for cell interface was tried by the special interface junction device constructed in High Energy Acceleration Research Organization (KEK). The two surfaces of cells were conjugated using the magic band in the high vacuum space, 10-8 to 10-9 Pa, after treatment of argon beam. Many trial pieces were manufactured. After then, 1.3 m X-band accelerating tube was produced and passed beam test of Stanford Linear Accelerator Center (SLAC). A course to introduce ultra-precision machine, challenge to ultra-precision machining, challenge to junction of interface, limit of cutting by diamond bite, and the EEM method are reported. (S.Y.)