Design, fabrication, and high-gradient testing of an X-band, traveling-wave accelerating structure milled from copper halves oleh Theodoros Argyropoulos, Nuria Catalan-Lasheras, Alexej Grudiev, Gerard Mcmonagle, Enrique Rodriguez-Castro, Igor Syrachev, Rolf Wegner, Ben Woolley, Walter Wuensch, Hao Zha, Valery Dolgashev, Gorden Bowden, Andrew Haase, Thomas Geoffrey Lucas, Matteo Volpi, Daniel Esperante-Pereira, Robin Rajamäki