1

ATF Status June/2004

H. HayanoH. Hayano

ATF: emittance status

beam study status

2004-2005 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.

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0 2 109 4 109 6 109 8 109 1 1010

Horizontal Emittancex emittance (run B)x emittance (run D)simulation (0.4% coupling)

bunch intensity [electrons/bunch]

GLC Design

2.0

3.0

4.0

5.0

6.0

7.0

8.0

0 2 109 4 109 6 109 8 109 1 1010

Vertical Emittancey emittance (run B)y emittance (run D)simulation (0.4% coupling)

bunch intensity [electrons/bunch]

GLC Design

3

High quality multibunch beam from RF-gun

Cathode block with CsTe coating

•Beam Intensity: ~1x1010/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

-0.5

0.0

0.5

1.0

1.5

-1 10 -8 0 1 10-8 2 10-8 3 10-8 4 10-8 5 10-8 6 10-8 7 10-8

RF gun beam at 80MeV

Time [sec]

4

Multibunch Vertical Emittance by Laser wire

0.0 100

5.0 10-12

1.0 10-11

1.5 10-11

2.0 10-11

0 2 109 4 109 6 109 8 109 1 1010

Projected Vertical Emittance of Multibunch

y emittance(01mode wire, 0423run)y emittance(00mode wire, 0518run)y emittance(01mode wire, 0518run)simulation (1% coupling)

Bunch Intensity

GLC Design

simulation 1% (ATF Goal)

Projected Y emittance is around 1% from X,However, twice much from GLC Design.Blowup at tail bunch is seen.

0.0 100

1.0 10-11

2.0 10-11

3.0 10-11

4.0 10-11

5.0 10-11

0 5 10 15 20

Vertical Emittance of Multibunch

Y_emittance(00mode, 1.6E9intensity)Y_emittance(00mode, 3.7E9intensity)Y_emittance(01mode, 6.3E9intensity)

Vertical Emittance of each bunch

Bunch Number

1.6x109

3.7x109

6.3x109

GLC Design

5

Preliminary result of Fast Ion Instability simulation

Behavior of Y emittance is very similar.

0.0 100

1.0 10-11

2.0 10-11

3.0 10-11

4.0 10-11

5.0 10-11

0 5 10 15 20

Vertical Emittance of Multibunch

Y_emittance(00mode, 1.6E9intensity)Y_emittance(00mode, 3.7E9intensity)Y_emittance(01mode, 6.3E9intensity)

Vertical Emittance of each bunch

Bunch Number

1.6x109

3.7x109

6.3x109

GLC Design

Emittance Versus Bunch Number

0.00E+00

1.00E-08

2.00E-08

3.00E-08

4.00E-08

5.00E-08

6.00E-08

0 5 10 15 20 25

Bunch

Normalized Y Emittance

6.00E+09

3.70E+09

1.60E+09

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.

10-7

10-6

10-5

10-4

0

10

20

30

40

50

0 500 1,000 1,500 2,000

DCCT_VAC_LOG ( >10mA )

(DR Vac pressure[Pa])/52mA Integ. of beam current [A.hour]

Time [hour]

20 bunch, 1 train goal

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.hour45 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

0.0 100

5.0 10-12

1.0 10-11

1.5 10-11

2.0 10-11

0 2 109 4 109 6 109 8 109 1 1010

Projected Vertical Emittance of Multibunch

y emittance(01mode wire, 0423run)y emittance(00mode wire, 0518run)y emittance(01mode wire, 0518run)simulation (1% coupling)

Bunch Intensity

GLC Design

simulation 1% (ATF Goal)

Projected Y emittance is around 1% from X,However, insufficient tuning of Y emittance.

0

5 10-12

1 10-11

1.5 10-11

2 10-11

0 2 109 4 109 6 109 8 109 1 1010

Projected Vertical Emittance of Multibunch

Projected y emittance (5/18/2004)Projected y emittance (4/23/2004)Projected Y emittance (6/15/2004)

bunch intensity

10

Multibunch Vertical Emittance

after 5.5 A.hours scrubbing

No big tail rise was seen,However, insufficient tuning of Y emittance.

0.0 100

1.0 10-11

2.0 10-11

3.0 10-11

4.0 10-11

5.0 10-11

0 5 10 15 20

Vertical Emittance of Multibunch

Y_emittance(00mode, 1.6E9intensity)Y_emittance(00mode, 3.7E9intensity)Y_emittance(01mode, 6.3E9intensity)

Vertical Emittance of each bunch

Bunch Number

1.6x109

3.7x109

6.3x109

GLC Design

Scrubbing seems to be effective

0

1 10-11

2 10-11

3 10-11

4 10-11

5 10-11

0 5 10 15 20

MB emittance after 5.5A.hour scrubbing

Y emi(1.1e9/bunch intensity)Y emi(4.1e9/bunch intensity)Y emi(5.2e9/bunch intensity)

bunch number

1.1x109

4.1x109

5.2x109

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

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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. 2004

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 2004-2006• 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-projectat ATF