1. IP BPM’s for ATF2 Vladimir Vogel KEK May30, 2005 Third Mini-Workshop on Nano Project at ATF

2.  z = 5 mm  z = 2 mm  z = 8 mm BPM frequency (Hz) BPM relativity resolution  z = 0.3 mm

3. The purpose of the bunch length shorting in ATF DR is: - to increase the sensitiveness to the beam offset, which will be worse when we will do shorter the sensor cavity length to reduce the beam angle sensitivity. - to start study how the BPM work with short bunch length. - study the interaction of high order modes and the working mode in the sensor cavity.

4. Frequency (GHz) Pout Y out X out Electric field in the sensor cavity Rv.t.=8mm Rv.t=6mm Rv.t=5mm BINP BPM’s X – Y coupling -40 ~ -50 db ATF2 IP BPM’s X-Y coupling Less than -80db (expected)

5. Reduction of the angle sensitivity, in the assuming that the signal proportional to the beam angle is equal to the signal from beam which has a 1 nm position displacement      Sin  Cos  The beam angle signal has phase difference 90 degree to the signal of the beam offset, We can use this fact! If Sin(  ) and Cos(  ) outputs will give us only 20db isolation, we can get enough reduction of the angle sensitiveness. Beam angle measurement in ATF extraction line. BINP cavity#4, 2001 Cavity effective length (m) Reduction of angle sensitivity BINP ATF2 F=6426MHz F=9000MHz Sin  position Cos  angle referencesensor

6. Q=1*10^10, Zload=50 Ohm,  ^-9 m,  z = 8 mm Thermal noise (dF=3 MHz, T = 300K) 1.57  V Qload=1500  Frequency (GHz) BINP BPM Leff =7mm Dtube =5mm BPM output voltage (V)

7. Block diagram of the BPM’s electronic for IP BPM 1.One reference cavity 2.Six sensor cavity

8. Method of determination the BPM resolution 1.Three BPMs for Y and X: 2. 10 nm step mover 3. Beam movers and two steering magnet in the fix distance

9. Welded bellows IRIE KOKEN CO., LTD NS122-1, Dmax=22mm Dmin=8mm L from 7 to 17 mm +2*3mm VLEPP type vacuum connectors F TM110 = 9 GHz, Leff. = 7 mm  = 2.0 Resolution 1-2 nm Angle sensitivity To 1 nm –200  rad IP BPM’s setup for Y position measurement Temperature control