1. Fabrication of KEK-ATF2 Q-BPM
3-D rendering
of a prototype Cavity BPM
Photo of a prototype Cavity BPM

2. ATF2 Cavity BPM(Q-BPM) Use dipole-excitation by e-beam (TM110)
C-band pill-box cavity with four pickup-ports
100nm resolution
6426MHz, C-band
x-y isolation: >45dB
Offset of electrical center < 10μm
Q > 5000
Design by Y. Honda

3. Prototype QBPM - Test and Performance
Prototype finished by 10/27/2005
Cold rf test at PAL(10/25) and KEK(12/7)
20dB isolation (dent model)
53dB isolation with tuning (no-dent model)
cavity frequency: 6420 MHz
Beam Test at KEK(12/2)
-20dB x-y isolation (dent model)
-36dBm/100nm signal for 1.6nC bunch
Cavity frequency: 6422MHz (KEK)
Overall Performance: Acceptable

4. 11-QBPM Fabrication Schedule

5. Overall Production Schedule
Prototype finished: 12/7/2005
Dimensions finalized : 1/6/2006
no dent for x-y isolation
use tuning for maximum isolation
long pipe for Q-magnet
11 Q-BPMs : 3/31/2006
26 Q-BPMs : 9/30/2006