1 H. Hayano ATF Status June/2004 H. Hayano ATF: emittance status beam study status plan nm-project collaboration & plan ATF review 6/17/2004

2 Single bunch Transverse Emittance by Laser wire X emittance determined by Ring Design. Measured data points are fit to simulation. Y emittance =6.5pm at GLC intensity, is below GLC design.

3 High quality multibunch beam from RF-gun Cathode block with CsTe coating Beam Intensity: ~1x10 10 /bunch Normalized Emittance:  y = 4 ~ 7 x10 -6 rad.m Bunch length:  z= 3 ~ 6 ps Q.E. of CsTe cathode: 16% initial, ~ 1% with RF ON & keep constant over few weeks

4 Multibunch Vertical Emittance by Laser wire Projected Y emittance is around 1% from X, However, twice much from GLC Design. Blowup at tail bunch is seen.

5 Preliminary result of Fast Ion Instability simulation Behavior of Y emittance is very similar. Schematic of the Fast-Beam Ion Instability simulation

6 DR vacuum pressure Low emittance was observed at DR pressure < 4 x10 -7 Pa Emittance growth observed with vacuum pressure > 4 x10 -7 Pa, even small bunch charge. 20 bunch, 1 train = 52mA ~15 A.hour (ex. 150mA.100hours)

7 DR scrubbing status GLC intensity: 20 bunch, 1 train = 52mA: 3 train = 156mA ~5.5 A.hour 45 hours 150mA EXT kicker pressure dominant 6/12/2004 ~ 6/14/2004

8 Extraction Kicker detail

9 Multibunch Vertical Emittance after 5.5 A.hours scrubbing Projected Y emittance is around 1% from X, However, insufficient tuning of Y emittance.

10 Multibunch Vertical Emittance after 5.5 A.hours scrubbing No big tail rise was seen, However, insufficient tuning of Y emittance. Scrubbing seems to be effective

11 Recent Beam studies in ATF Polarized Positron study FEATHER study RF-gun study ODR study SR study( interference, streak, longitudinal osc.) XSR study LW study X-band cavity BPM study SLAC nm-BPM study SLAC ring-BPM study QMUL FONT study

12 Other Developments in ATF Wiggler study Correction coil for residual kick is preparing. Damping time and emittance will be tested in fall-run. X-Y coupling at extraction Multi-pole component of kicker and septum is under study. KEK nm-BPM study 3 set of new C-band cavity BPM with laser based active stabilization. fabrication is now under way. S-band detuned structure study Basic study of new detuned method is now under way. Fast sweep LW at EXT plan (UK) Fast sweep over multibunch scan is now under planning.

13 FEATHER stripline Kicker FEATHER BPM Fast feedback control study for collision feedback FEATHER(KEK), FONT(UK) Collision feedback

14 ODR( Optical Diffraction Radiation ) beam size monitor Achieved resolution ~10µm

15 Beam image (x:39µm, y:7.3µm) X-ray SR beam size monitor Achieved resolution ~6µm

16 Cavity BPM nm resolution study LLNL Design mover, Improved electronics, installed Mar Achieved resolution 90nm

17 KEK nm-BPM study 3 cavity BPM system 1 cavity BPM almost finished. 2 more will be in September. 1 mover stage done. 2 more under fabrication. Active mover & nm sensor are preparing. Reference monitor & optical anchor is under study.

18 ATF Plans for MB emittance study Y emittance will be confirmed by Laser Wire after scrubbing. Longitudinal oscillation is studied now. Wiggler study Damping time and emittance will be confirmed with wiggler ON. Extraction of low emittance beam multi-pole component of kicker and septum are under study. nm resolution BPM test & demonstration Development of new precise mover & new cavity-BPM electronics(SLAC). KEK version of cavity BPM and active mover development are under way. combination of two system for study of active stabilization. Fast feedback test & demonstration Basic test of feedforward and feedback are under way. Stable beam extraction is essential. Fast feedback test by 3 train extraction will be done. Instrumentation developments LW, XSR monitor, ODR monitor, MB-BPM, (SB, MB) longitudinal feedback, etc.

19 Plan : nm-project at ATF