High Resolution Cavity BPM for ILC Final Focal System (IP-BPM)

Figure 1: IP-BPM Block ATF2 is an extension of ATF, a test facility for ILC accelerator development. ATF is the only facility today which can achieve beam emittance of the ILC specification. Experimental studies for ILC final focus is planned at ATF2, and is starting its operation at October, 2008. There are two main goals for ATF2. First, achievement of 35 nm beam size at the IP. Second, control of beam position in 2 nm precision at the IP. Old model cavity BPMs at ATF have achieved 17 nm position resolution so far [2]. But to achieve the two goals, a BPM of 2 nm position resolution (IP-BPM) is required at ATF2. We have fabricated two hot models of IP-BPM, and tested its performance at ATF.