Optics Tuning and Issues
Hiroshi Sugimoto
on behalf ofSuperKEKB Beam Optics & Commissioning Group

Belle

Overview•

We have successfully squeezed beta* down to 2 mm in both rings.

•

Beam optics measurement is based on closed orbit analysis.
- Beam measurement with Turn-by-Turn BPMs are partially performed,
but still not mature for the daily optics correction. (Need more experience)•

The correction of IP parameters mainly based on measured luminosity and beam size.

•

Beam orbit in the interaction region (IR) strongly affects performance of optics tuning.

•

Unexpected degradation of LER global XY-coupling.

•

Off-momentum optics analysis has just started.

07/08/2019

SuperKEKB Review ‘19

2

Global and Local Optics Correction•

Global correction and low emittance tuning- Same as Phase 1 operation except for the region near IR.

•

Waist scan

Optics parameters at IP- Estimation is, in principle, possible.
- However, It’s difficult to confirm its reliability.
~ Poor sensitivity due to the very small beta*~ Connection failure of QC1L{EP} BPMs

- Therefore the correction mainly relies onluminosity performance and beam size so far.

07/08/2019

SuperKEKB Review ‘19

3

Region in the vicinity of IR
Normal skew magnet affects both XY-coupling and vertical dispersion.

•

Minimize,<latexit sha1_base64="/at1l4Qyiw2t93jSiiXVw156zTw=">AAACsnichVHLThRBFD00Ki+RETYkbDpMMCSEye0JCYYVERcseThApGFSXdRAhZruprtmyDjxB9y6YMEKExfEDzBuZeMPuOATCEtM3LjwTk8nRoh4O1V16tQ9t071DWKjU0t02eP0Pnj4qK9/YHDo8fCTkcLT0Y00aiRSVWRkomQrEKkyOlQVq61RW3GiRD0wajM4XOqcbzZVkuoofGVbsdqpi/1Q17QUlqlqYdaXB3q37Kujhm66/ktlrHB9ZUW1tVt2Z9xjnnOWiWqhSCXKwr0LvBwUkcdKVPgMH3uIINFAHQohLGMDgZS/bXggxMztoM1cwkhn5wpvMcjaBmcpzhDMHvK8z7vtnA1536mZZmrJtxgeCStdTNF3Oqcb+kaf6Ip+/bNWO6vR8dLiNehqVVwdeTe+/vO/qjqvFgd/VPd6tqjheeZVs/c4YzqvkF19883JzfrC2lT7GX2ga/Z/Rpd0wS8Imz/kx1W1dnqPn4C98B/jBnm323EXbJRLHpW81bni4ou8Vf2YwCSmuR/zWMQyVlDh+u/xBV9x4cw5rx3hyG6q05NrxvBXOOY3dV2giw==</latexit>

V. dispersion

βx ,!

ηx [mm]V. leakage orbit

Weighting Factor•

ηy [mm]⌘y2 + w2 y 2⌘

The weighting factor is

r4 r3 [m−1 ] r2 [mm] r12!
βy [m1/2 ]•empirically chosen.

07/08/2019

SuperKEKB Review ‘19

4

Example of Optics Correction - Phase 2 -XY-coupling and vertical dispersion before and after the optics correction.

•

After Correction

∆ỹ5

∆ỹ4

∆ỹ3

∆ỹ2

∆ỹ1

0.2
0.0
−0.2
0.2
0.0
−0.2
0.2
0.0
−0.2
0.2
0.0
−0.2
0.2
0.0
−0.2
0.2
0.0
−0.2
20

∆ηy [mm] ∆ỹ6

∆ỹ5

∆ỹ4

∆ỹ3

∆ỹ2

∆ỹ1

Before Correction∆ηy [mm] ∆ỹ6

HER

0
−20

−1500

07/08/2019

−1000

−500

0
500
Path length s [m]

1000

1500

0.2
0.0
−0.2
0.2
0.0
−0.2
0.2
0.0
−0.2
0.2
0.0
−0.2
0.2
0.0
−0.2
0.2
0.0
−0.2
20
0
−20

−1500

IP
SuperKEKB Review ‘19

−1000

−500

0
500
Path length s [m]

1000

1500

5

Beam Orbit in IR and the Performance of Optics Correction•

IR beam orbit is sometimes adjusted locally to mitigate beam pipe heating and/or
background (BG) level of the physics detector.

•

It affects beam optics and performance of optics tuning also.

•

Example: IP localized vertical angle and vertical dispersion in HER.
100

Before orbit tuning

ηy [mm]50

The large vertical dispersion leaked from IR
was not correctable owing to hardware limitof correctors.
07/08/2019

0
−50
−100
−1500

SuperKEKB Review ‘19

After orbit tuning(+ optics correction)
−1000

−500

0

500

1000

1500

Postion s [m]6Performance of Global Optics Correction
Phase 1(<latexit sha1_base64="fQROHkI6kGrOPCK3jufuyDlpt+M=">AAACwnichVFNTxNRFD0MCrUKLbIxcdPY1GBCyh1DAjEhaYSFSwoWSDq1eTM8ysh8MfPaUIfxB/gHXLhS48L4A/wBbnSrccFPMC4xcePC2+kYUQLcycw797x77pz3rhk4dqSIjka00UuXx8ZzV/JXr01MFopT1zcivxtasmH5jh9umSKSju3JhrKVI7eCUArXdOSmubc82N/syTCyfe+h6gey5YqOZ+/YllBMtYtLM8aKdJQoGaZUoh0fzPaTuRP4zqPYcIXaDd04dKMkefonaxqVVtIulqlKaZROAz0DZWSx6hffw8A2fFjowoWEB8XYgUDETxM6CAFzLcTMhYzsdF8iQZ61Xa6SXCGY3eNvh7NmxnqcD3pGqdrivzj8hqwsoUJf6S0d00d6R9/o15m94rTHwEufV3OolUG78OzG+s8LVS6vCrt/Ved6VtjBYurVZu9BygxOYQ31vSfPj9fvrVXi2/SKvrP/l3REH/gEXu+H9aYu116c48dkL3xjPCD9/3GcBht3qzpV9fp8uXY/G1UON3ELMzyPBdTwAKtocP/X+ITP+KKtaI+1fS0almojmWYa/4R2+BubzanX</latexit>

rms

[%]

/ ( x)

rms

x,y / x,y )

( y)

rms

( ⌘x,y )rms [mm]<latexit sha1_base64="EDJ9kIuS5OFFUTmp+VRuG7fDib8=">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</latexit>

Phase 2Phase 3

LER

HER

LER

HER

LER

HER

3/3

3/3

2/4

3/3

3/7

3/4

0.009

0.006

0.014

0.008

0.016

0.009

8/2

11 / 210 / 4

9/3

14 / 320 / 3

HER (βx∗ , βy∗ ) = (100 mm, 3 mm)∗
LER (βx ,07/08/2019βy∗ ) = (200 mm,

SuperKEKB Review ‘19

3 mm)( x⇤ ,<latexit sha1_base64="B+tmh8hFYksOBZ6kH+WDNwXR9h8=">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</latexit>(<latexit sha1_base64="B+tmh8hFYksOBZ6kH+WDNwXR9h8=">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</latexit>⇤x,⇤y ) = (80 mm,⇤y ) = (80 mm,

2 mm)
2 mm)
7

Performance of Global Optics Correction
Phase 1(<latexit sha1_base64="fQROHkI6kGrOPCK3jufuyDlpt+M=">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</latexit>

rms

[%]

/ ( x)

rms

x,y / x,y )

( y)

rms

( ⌘x,y )rms [mm]<latexit sha1_base64="EDJ9kIuS5OFFUTmp+VRuG7fDib8=">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</latexit>

Phase 2Phase 3

LER

HER

LER

HER

LER

HER

3/3

3/3

2/4

3/3

3/7

3/4

0.009

0.006

0.014

0.008

0.016

0.009

8/2

11 / 210 / 4

9/3

14 / 320 / 3

HER (βx∗ , βy∗ ) = (100 mm, 3 mm)∗
LER (βx ,07/08/2019βy∗ ) = (200 mm,

SuperKEKB Review ‘19

3 mm)( x⇤ ,<latexit sha1_base64="B+tmh8hFYksOBZ6kH+WDNwXR9h8=">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</latexit>(<latexit sha1_base64="B+tmh8hFYksOBZ6kH+WDNwXR9h8=">AAACu3icSyrIySwuMTC4ycjEzMLKxs7BycXNw8vHLyAoFFacX1qUnBqanJ+TXxSRlFicmpOZlxpaklmSkxpRUJSamJuUkxqelO0Mkg8vSy0qzszPCympLEiNzU1Mz8tMy0xOLAEKxQuYacQkpZYkxlfEaenUQZiVcVqathoWBnUxuYklGUW51bm5tTp1RshczXgBZQM9AzBQwGQYQhnKDFAQkC+wnSGGIYUhnyGZoZQhlyGVIY+hBMjOYUhkKAbCaAZDBgOGAqBYLEM1UKwIyMoEy6cy1DJwAfWWAlWlAlUkAkWzgWQ6kBcNFc0D8kFmFoN1JwNtyQHiIqBOBQZVg6sGKw0+G5wwWG3w0uAPTrOqwWaA3FIJpJMgelML4vm7JIK/E9SVC6RLGDIQuvC6uYQhjcEC7NZMoNsLwCIgXyRD9JdVTf8cbBWkWq1msMjgNdD9Cw1uGhwG+iCv7Evy0sDUoNl43JMEdAswxIARZIgeHZiMMCM9QwM9w0ATZQcnaFRxMEgzKDFoAOPDnMGBwYMhgCEUaP4chkMMpxnOMNkyJTNlMeVAlDIxQvUIM6AAplIAeS+loA==</latexit>⇤x,⇤y ) = (80 mm,⇤y ) = (80 mm,

2 mm)
2 mm)
8

LER Global XY-coupling in Phase 1 and 2

Phase 1

Phase 2
* Steering magnets used in themeasurements are different.
07/08/2019

SuperKEKB Review ‘19

9

A Possible Source of the XY-coupling Degradation•

A large number of permanent magnets (PMs) are attached to the LER
beam pipe for suppression of e-cloud effects.

Phase 2~Phase 1•
07/08/2019

It creates unexpected effects to the LER beam?
SuperKEKB Review ‘19

10

Configuration
Changeof PMsafter Phase2
Vacuumsystemupdatesfor Phase-3
Electron cloud in LER (1/3): Re-alignment of PMs -2• To study the influence of PM units during Phase-3, 3 areas
with different conditions were prepared; (with Optics group)

Y. Suetsugu• East arc: PMs were just re-aligned using a tool .
• South arc: PMs were re-aligned, and also the number was
reduced from 4 to 2. (only near antechambers)• North and West arc: Almost the same condition to that inPhase-2 (no re-alignment).
PM unit with 4 PMs

PM unit with 2 PMs

North

East

West

South

1

07/08/2019

SuperKEKB Review ‘19

11

Measurement in Phase 3

No Change
Re-aligned
andreduced by half
07/08/2019

Re-aligned
SuperKEKB Review ‘19

No Change
12Comparison
Phase 207/08/2019

Phase 3

SuperKEKB Review ‘19

13

Observation in Phase 3 and Next Plan•

Does the configuration change of PMs improve XY-coupling?
-> It looks no improvement so far.

•

We should consider strategy again to identify the source of degradation.

•

we may have to re-check offset of some of quadrupole magnets
with beam-based alignment technique.

07/08/2019

SuperKEKB Review ‘19

14

Issue on Vertical Beam Size Measurement in Phase 1•

HER

Discrepancy between measured beam size and that expected by beam optics in HER.

MAC’16

Summary of series of investigation after MAC16

Vertical Emittance

LER

HER

X-ray Monitor

10 pm

40 pm

Beam Optics

10 pm

10 pm

LER!
y = 67 m"y ⇠ 12 pm

HER!
Estimation with beam size measurement

Estimation with measured optics

"y ⇠ 120 pm"y ⇠ 10 pm•

A difference between LER and HER
is beta function at the x-ray source point.

Flanagan-san’s talk?

The exact value is still under discussion.
2016/06/13

07/08/2019

The 21th KEKB Accelerator Review Committee

21

LER

SuperKEKB Review ‘19

y = 67 m

HER

y = 7.6 m

15

Study on X-ray Beam Sime Monitor (XRM) in Phase 2•

HER

Vertical beam size is measured with changing global vertical dispersion
and beta function βys at the X-ray source point.
100

We Find that•

Measured size becomes less sensitive
to the vertical-dispersion knob
when βys becomes smaller as expected.

•

Vertical beam size [µm]βys = 28 [m]The minimum measured beam size is
independent on βys•

βys = 14 [m]80βys = 7.6 [m]

60

40

20
−2

0
1
−1
Knob strength [arb. unit]

2

Dispersion knob [arb. unit]

The monitor system has some smearing effects which limit the resolution.
Comprehensive study estimates the size of smearing effect is ~7 µm.

07/08/2019

SuperKEKB Review ‘19

16

Performance of Global Optics Correction•

Measurement at low beam current ~40mA.

•

The LER vertical emittance in Phase 3 is somehow lower than that of Phase 2.
<- Is it true?

Phase 1

Phase 2Phase 3

LER

HER

LER

HER

LER

HER

rms

[%]

3/3

3/3

2/4

3/3

3/7

3/4

/ ( x)

rms

0.009

0.006

0.014

0.008

0.016

0.009

( ⌘x,y )rms [mm]8/2

11 / 210 / 4

9/3

14 / 320 / 3"y [pm]

~10

(~40)

~20

~10

~10

~10

"y /"x [%]~0.6(~0.9)

~1.1

~0.2

~0.6

~0.2

(

x,y / x,y )<latexit sha1_base64="fQROHkI6kGrOPCK3jufuyDlpt+M=">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</latexit>

( y)

rms

<latexit sha1_base64="EDJ9kIuS5OFFUTmp+VRuG7fDib8=">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</latexit><latexit sha1_base64="LzRnzhlHDlFdem87kdbLBqlCU0Y=">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</latexit><latexit sha1_base64="9/gmDIAU3iM0t2/MbOdJMgbRDiw=">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</latexit>

07/08/2019

SuperKEKB Review ‘1917

Off-momentum XY-coupling•

Vertical beam size blowup with rf-frequency change.

•

Off-momentum XY-coupling is indeed larger than that of on-momentum.

•

Its error source and countermeasure is under discussion.

HER

p/p =

0.17 %

p/p = 0p/p = 0.17 %<latexit sha1_base64="m4Cep1fZmDP+9WKsPvpMXCojHRU=">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</latexit><latexit sha1_base64="N+AQHVcrrG1E+ecwll9r+SG4bhg=">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</latexit>

0.0
−0.1
0.1
0.0
−0.1
0.1
0.0
−0.1
0.1
0.0
−0.1
0.1
0.0
−0.1
0.1
0.0
−0.1
−1500

07/08/2019

−1000

−500

0

500

Position s [m]

1000

0.1

∆ỹ6 ∆ỹ5 ∆ỹ4 ∆ỹ3 ∆ỹ2 ∆ỹ1

0.1

∆ỹ6 ∆ỹ5 ∆ỹ4 ∆ỹ3 ∆ỹ2 ∆ỹ1

∆ỹ6 ∆ỹ5 ∆ỹ4 ∆ỹ3 ∆ỹ2 ∆ỹ1

<latexit sha1_base64="x59slDeBUrSfaYv7CW6MGeMvdTw=">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</latexit>

0.0
−0.1
0.1
0.0
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0.1
0.0
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0.1
0.0
−0.1
0.1
0.0
−0.1
0.1
0.0

−0.1
1500 −1500

−1000

−500

0

500

Position s [m]SuperKEKB Review ‘19

1000

0.1
0.0
−0.1
0.1
0.0
−0.1
0.1
0.0
−0.1
0.1
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1500 −1500

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Position s [m]18Summary•

We have successfully squeezed beta* down to 2 mm in both rings.

•

Beam orbit in IR strongly affects performance of global optics correction.
- We should take care not only beam optics but also beam pipe heating and BG level.

•

Tuning of IP parameters is mainly based on luminosity performance and beam size.

•

Degradation of LER XY-coupling compared with that of Phase 1.

•

Need more consideration on the measured vertical emittance including calibration of
measurement system.

•

Off-momentum optics analysis has just started.

07/08/2019

SuperKEKB Review ‘19

19

Thank You for Your Kind Attention.

Spare Slides

HER Optics in the Vicinity of IP

07/08/2019

SuperKEKB Review ‘19

22

LER Optics in the Vicinity of IP

07/08/2019

SuperKEKB Review ‘19

23

Beta Squeezing•

Phase 2: Step by step squeezing with optics correction is essential.

•

Phase 3: Experience in Phase2 helps the squeezing.
Phase 3βx∗ [mm]
(HER)

400
200

2

βx∗ [mm]
(LER)

0
8
6
4
2
0

4-0

07/08/2019

200
0
8
6
4
2
0
400
200

βy∗ [mm](LER)

βx∗ [mm](LER)βy∗ [mm]
(LER)

200

-0
018

400

βy∗ [mm]
(HER)

0
8
6
4
2
0
400

βy∗ [mm](HER)

βx∗ [mm](HER)

Phase 2

1
2

-0
018

5-0

1
2

-0
018

6-0

1
2

-0
018

7-0

0
8
6
4
2
0

1
2
SuperKEKB Review ‘19

-0
019

4-0

1
2

-0
019

5-0

1
2

-0
019

6-0

1
2

-0
019

7-0

1

24

Optics Correction and Beam Injection•

Beam injection is very sensitive to optics distortion as well we injectedbeam quality.

•

XY-coupling is important for high injection efficiency and low BG.
Optics Correction
Beam Current
Injection rate

07/08/2019

SuperKEKB Review ‘19

25

S

Orthogonal Correctors
•

N

N

N

Some of sextupole magnets have skew quadrupole coils.
Symmetrical / asymmetrical excitation of skew-corrector pare can be used asorthogonal correctors for coupling and vertical dispersion.
The orthogonality allows us to reduce size of the matrix to be solved.
Symmetrical Excitation(XY-coupling corrector)

S

Asymmetrical Excitation(Vertical-dispersion corrector)

X-Y coupling
R1,R4

Coupling
parameters

R2
R3

Verticaldispersion
Skew
quadrupole

N

K1s

SD

SD

physical ηyπ
07/08/2019

SuperKEKB Review ‘19

26

Horizontal Dispersion in the Vicinity of IR - HER •Horizontal localized angle bump is applied to mitigate BG.

•

As the result, Horizontal residual dispersion is large in the vicinity of IP.

07/08/2019

SuperKEKB Review ‘19

27

Beta Beating - LER -07/08/2019

SuperKEKB Review ‘1928

Residual XY-coupling - LER -07/08/2019

SuperKEKB Review ‘19

29

Residual Dispersion - LER -07/08/2019

SuperKEKB Review ‘1930

Beta Beating - HER -07/08/2019

SuperKEKB Review ‘19

31

Residual XY-coupling - HER -07/08/2019

SuperKEKB Review ‘19

32

Residual Dispersion - HER -07/08/2019

SuperKEKB Review ‘19

33

Off-momentum XY-coupling
p/p =

LER

0.26 %

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0.0
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0.0
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0.1
0.0
−0.1
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0.1
0.0
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−1500

07/08/2019

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0

500

Position s [m]

1000

0.1

∆ỹ6 ∆ỹ5 ∆ỹ4 ∆ỹ3 ∆ỹ2 ∆ỹ1

0.1

∆ỹ6 ∆ỹ5 ∆ỹ4 ∆ỹ3 ∆ỹ2 ∆ỹ1

∆ỹ6 ∆ỹ5 ∆ỹ4 ∆ỹ3 ∆ỹ2 ∆ỹ1

<latexit sha1_base64="N+AQHVcrrG1E+ecwll9r+SG4bhg=">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</latexit>

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0.1
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1500−1500

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500

Position s [m]SuperKEKB Review ‘19

1000

0.1
0.0
−0.1
0.1
0.0
−0.1
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0.0
−0.1
0.1
0.0
−0.1
0.1
0.0
−0.1
0.1
0.0

−0.1
1500−1500

−1000

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0

500

1000

1500

Position s [m]34Optics Measurement•

Beta function:xi =Orbit response analysis with DC dipole kicks.
•

Dispersion function:i 0

2 sin ⇡⌫

RF frequency

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Betatron (XY-) coupling:✓ cos (| i

0|

⇡⌫)

Orbit changex⇠f Phase slip factor

Frequency change

Vertical leakage orbits induced by horizontal dipole kicks.
•

Turn-by-Turn measurement:
Partially performed, but not mature for the daily operation.
<- Need more experience and investigation.

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35

Estimation of IP Parameters•

Twiss parameter propagation with model transfer matrix.
⎛

⎛
⎞
β
C2
⎝ α ⎠ = ⎝ −CC ′
C ′2
γ IP

•

−2SC
SC ′ + CS ′−2S ′ C ′

⎞⎛
⎞
S2
β
−SS ′ ⎠ ⎝ α ⎠
S ′2
γ BPM

Solving nonlinear equation numerically with measured optics at QC{12} BPMs.
2
βBPM = C 2 βIP − 2SCαIP + S 2 (1 + αIP
)/βIP

•

Estimation of waist assuming drift motion.
2
βwaist ∼ βIP /(1 + αIP)
2∆s ∼ αIP βIP /(1 + αIP)

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Estimation of IP Parameters - HER •Estimation with measured optics
and model transfer matrix<latexit sha1_base64="5+CbduG9KvUJegx0Q/NvH+LXibU=">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</latexit><latexit sha1_base64="rwRKNmudKPJCDnufC4M3mI2qEDo=">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</latexit>

IP = 282 mm / 2.6 mm
waist = 86 mm / 2.0 mms=

130 mm /1.1 mm<latexit sha1_base64="BlGQDa+Tv62KOTACvhfpHd0uFz0=">AAACsnichVE9TxtBEH0+AiGGgEOaSGksLFAamzmCFISEZCUUKQFjQGBk7R1rc2LvQ3drS2DhH5A2RQoqkFJE/ACUNm7yByj8ExAlkdJQMD6fBAkKmdPevn07b/btjhUoJ9JE3ZQx8GRw6Onws/TI6POx8cyLifXIb4S2LNu+8sNNS0RSOZ4sa0cruRmEUriWkhvW/ofe/kZThpHje2v6IJA7rqh7Ts2xhWaqmslXlqTSIhtlF/PmW2pXXKH3QrflukftmXbeLJj3qWomRwWKI/sQmAnIIYllP3OOCnbhw0YDLiQ8aMYKAhF/2zBBCJjbQYu5kJET70scIc3aBmdJzhDM7vO/zqvthPV43asZxWqbT1E8QlZmMUUX9I2u6Sed0SXd/LNWK67R83LAs9XXyqA6/ulV6fd/VS7PGnt3qkc9a9QwH3t12HsQM71b2H198/DLdWlhdao1Tad0xf5PqEsdvoHX/GV/XZGrx4/4sdgLvxg3yPy7HQ/B+mzBpIK5Mpcrvk9aNYzXmMQb7sc7FPERyyhz/c/4jh/oGHPGliEMu59qpBLNS/wRhroFyzuhqQ==</latexit>•

Large offset of horizontal waist
position is not understood.

•

We tried luminosity run withadjusted horizontal waist.
However the luminosity performance is not improved or rather worse.

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37

Vacuum system updates for Phase-3
Electron cloud in LER (1/3): Re-alignment of PMs -1• Permanent magnets (PMs) around beam pipes, which isadopted as a countermeasure against the electron cloud
effect, worked very well, but they were suspected to have an
influence on the beam optics, i.e., the x-y coupling.
• It was pointed out that the
Measurement of quadrupole component
misalignment of PM units along
beam pipes is likely to increase
the quadrupole component, andcan be a cause of x-y coupling.
(R. Ueki, MAG Group)
PM units attached to LER beam pipes

R. Ueki

1

07/08/2019

SuperKEKB Review ‘19

Design Machine Parameters
Machine Parameters
2013/July/29

LER

HER

unit

E

4.000

7.007

GeV

I

3.6

2.6

A

1.04

mA

2,500

Number of bunches
Bunch Current

1.44
3,016.315

Circumferenceεx/εy3.2(1.9)/8.64(2.8)

4.6(4.4)/12.9(1.5)

Coupling

0.27

0.28

βx*/βy*32/0.27

25/0.30
83

Crossing angle

nm/pm():zero current
includes beam-beam

mm
mrad

αp

3.18x10-4

4.53x10-4σδ

8.10(7.73)x10-4

6.37(6.30)x10-4():zero current

Vc

9.4

15.0

MV

σz

6.0(5.0)5(4.9)mm

νs-0.0244-0.0280

νx/νy44.53/46.57

45.53/43.57

U0

1.86

2.43

MeV

τx,y/τs43.2/21.6

58.0/29.0

msec

ξx/ξy

0.0028/0.0881

Luminosity

07/08/2019m():zero current

0.0012/0.0807

8x1035

SuperKEKB Review ‘19

cm-2s-1

39