Cavity beam position monitor system for the Accelerator Test Facility 2

• Main Authors: Y. I. Kim, R. Ainsworth, A. Aryshev, S. T. Boogert, G. Boorman, J. Frisch, A. Heo, Y. Honda, W. H. Hwang, J. Y. Huang, E-S. Kim, S. H. Kim, A. Lyapin, T. Naito, J. May, D. McCormick, R. E. Mellor, S. Molloy, J. Nelson, S. J. Park, Y. J. Park, M. Ross, S. Shin, C. Swinson, T. Smith, N. Terunuma, T. Tauchi, J. Urakawa, G. R. White
• Format: Article
• Language: English
• Published: American Physical Society 2012-04-01
• Series: Physical Review Special Topics. Accelerators and Beams
• Online Access: http://doi.org/10.1103/PhysRevSTAB.15.042801

The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. This paper describes the high resolution cavity beam position monitor (BPM) system, which is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.423 GHz, and S-band at 2.888 GHz with an increased beam aperture. The cavities, electronics, and digital processing are described. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1  μm for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm.