KEKB Status
since Feb. 2003
H. KoisoFeb. 16, 2004 @ KEKB Review•••

Achieved 10/nb/s
Continuous InjectionPlansKEKB History

Luminosity Performance• Peak luminosity has exceeded the design
value of 10/nb/s.
Lpeak= 8.26->11.61/nb/s• Integrated luminosity /day, /7days, /30days
are also improved much (almost doubled).
434/2579/ 8783->819/4745/17240 /pb( 1.89 / 1.84/1.96)• Total luminosity 197.5/fb• Now we guarantee 19.5/fb/month to Belle.
• We have been successfully operating inContinuous Injection Mode (CIM) since Jan.
2004.

The Second Best Day 783.0/pb

The Best Day 818.8/pb

Daily Luminosity since Jan. 2004

Machine parametersDate

12/18/2003

RingLER

Horizontal Emittance

HER

18

Beam current

10/29/2002
241503

Number of bunches

LER
18

1132

1.17

24

nm

1454

1281

Bunch current

HER
949

1184
0.884

Bunch spacing

1.8 or 2.4 (3.77sp)

Bunch trains

1

1.23

0.80

1.8 or 2.4 (4.08sp)
1103

116

Vertical size at IP

2.3

2.3

2.9

2.9µm

5.5

3.4

7.5

5.0%

β*x/β*y59/0.58

56/0.759/0.62

61/0.7cm

Beam-beam parametersξx/ξy0.104/0.069

0.090/0.053

0.078/0.045

Emittance ratio εy/εxBeam lifetime at collision
Luminosity (Belle CsI)
Luminosity records
per day/7 days/30 daysmAmHorizontal size at IP σ*x
σ*ymA

0.071/0.053

125 @1503 mA 216@1132 mA
11.61(total)
819/4745/17240 (197.5/fb)

103

68@1454mA

121

197@949mA

8.26
434/2579/8783 (109.7/fb)

min/nb/s/pbµm

Machine Parameters (cont’d)• Bunch fill pattern/bunch spacing– 4.08 (49/12) -> 3.77 (49/13) (April 2003-)– 3.5 (49/14) Could not use due to heating of IP
bellows and LER ante-chamber in June 2003.

• Stored currents– LER 1861mA– HER 1187mA world’s highest with SCC• RF Voltage– LER 8 MV (LER)– HER 13 -> 15 MV Oct. 2003: Added 2 ARESs–-> 14 MV Jan. 2004: Removed 1 SCC–due to vacuum leak

Continuous Injection Mode
• Continuous datataking during
injection• 3.5msec veto atinjection• 10Hz injection• e+<->e- changein every 20 min.
• 3~4 times toHER, once to LER

10/nb/s × 86400sec = 864/pb/day
LER current is limited due to heating of the septum
chamber and HER vertical size blow-up.

Specific Luminosity

Specific luminosity has been improved by 25%.

10/29/2002
5/9/2003
12/18/2003

Simulations M.Tawada, et al.

IP Knobsscan• 8 vertical bumps at SD sextupoles in each side of IP.
• Vertical dispersion and its angle, x-y coupling components are
independently adjustable. R1,R2,R3,R4,EY, and EPY• Knobs to adjust vertical waists (fudge factors of QCS and QC1),
longitudinal collision point (rf room phase) are also available.

Luminosity Tuning with IP Knobs
dispersionLERHER

x-y coupling• Luminosity is improved by 20-30% by tuning with IP knobs.
• Luminosity looks recovered quickly after the optics correction
when we start tuning at the previous optimum values.

Sextupole Adjustment• many degrees of freedom: 52+2(LER) families• Takes time to optimize.

Electron Clouds in LER
H. Fukuma, et al.
!
"#$%&#'(!

1 train, 1284 bunches, 3.77 spacing5"#$%&#'(4Beam size@IP(micron)• Connection of solenoids waschanged at ~300 points toeliminate field-free region indrifts.
• Beam size were almost
unchanged.
• No problems in x-y couplingcorrection.
• LER is operated in the newconnection.

3.77 (before connection-change)
3.77 (before connection-change)
3.77 (after connection-change)
3.77 (after connection-change)

32

10400

600

800

1000

1200

Beam current(mA)

1400

1600

1800

Fight for High Current•

Heating of components bysynchrotron light andHOM•

Discharge and melt down•

Vacuum leak

KEKB: QC4RE Bellows

These damaged components
were replaced.

HER Movable
Mask

Y. Suetsugu, et al.

LER Septum ChamberImprovements• New 2 ARES cavities in HER D4• New IR cambers QC1RE QC2RE QC2LP/E– Wider vertical aperture 58 -> 76 mm @QC1RE– Reinforced cooling system• New masks (longer type) in HER D9,D12• New septum chambers with new type fingers- Baking was necessary.
• Removed ante-chamber, made test station inLER D6• Installed a new ante-chamber• New BPMs at 4 skew quads. in HER• One-pass BPMs 21/ring• More solenoids and permanent magnets inLER

Improvements• Corrected inadequate algorithm in orbit correction.
Orbit and energy drift were reduced.
• Beam-based mapping of BPM. Consistency errors werereduced (<.3 mm).

Annual Report 2003

Tune Feedback
Meas.
Set

Works very wellDiff. is kept
<0.0005

Ref. line
T. Ieiri and Y. Ohnishi, et al.

Injector PerformanceElectron Emittance @ Linac End (2003, 10-12)

Positron Emittance @ Linac End (2003, 10-12)

Y. Ogawa, et al.

• 2 bunch/pulse e+ injection scheme are always applied.
• The beams from Linac are stable and the injection rate havebeen improved. Records: e+ 3.72mA/s, e- 5.53mA/s

PlansHigher Currents• HER current is gradually being increased.
1100 -> 1184 mA
1100 ->~1140 mA…->1200mA

Dec. 2003
Jan. 2004 line-out D10C

• LER current -> 1800mA– Limit depends on luminosity performance

Higher Specific Luminosity• Smaller βx* in both rings– 60 -> 40 cm (10~20%)• Better choice of tunes– HER tunes are set close to LER (20~30%)– Momentum compaction may have to be adjusted to avoid
the synchro-betatron resonance 2νx + νs = integer (νx =.511@14MV)

Plans (cont’d)More Bunches• 3.5 spacing

Next Milestone before Installation ofCrab Cavities• Total integrated luminosity >500/fb• 1/fb/day– 13/nb/s × 1 day = 1.12/fb/day• 24/fb/month– = 0.8/fb/day × 30 days

• >200/fb/year