Tevatron Issues and Operations

All Experimenter Meeting

Dean Still

Monday, February 22, 2010

AEM D. StillTevatron Issues and Operations 2

Collider II Integrated Luminosity

Courtesy: RunCo Team 0900 meeting Feb, 19, 2010

AEM D. StillTevatron Issues and Operations 3

Beam Intensities at Start of HEP

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

5500

6500 6700 6900 7100 7300 7500

Store #

Pb

ar In

ten

sity

[1

09]

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

Pro

ton

Inte

ns

ity

[1

09 ]

Pbar

Proton

Currently Limiting Pbar Intensity due to Losses in Squeeze

Requesting lower pbars due to lossesIn Squeeze and Collisions

Effective Emittance and Specific Luminosity

8

10

12

14

16

18

20

22

24

26

28

6500 6600 6700 6800 6900 7000 7100 7200 7300 7400 7500 7600

Store #

Eff

ecti

ve E

mit

tan

ce [

p m

m m

rad

]

-6.0

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Sp

ec

ific

Lu

min

os

ity

Effective Emittance

Specific Luminosity

Sequence of Quench

Number Quenches

Since Sept 2009

HEP 12

Squeeze 10

Ramp 5 ( not all store loss)

150gev 14

TOTAL 41

AEM D. StillTevatron Issues and Operations 44

Problems

• Losses at LMB1SD (~29rads/sec – quench ~50rads/sec) remain high during squeeze LBSEQ 7-14.

• Pbar vertical emittance blow up at and pbar beam loss at end of squeeze LBSEQ 21-25.

• Pbar vertical emittance blow up at and pbar beam loss at Initiate Collisions.

AEM D. StillTevatron Issues and Operations 5

Current Problems

Pbars falling out Pbar vert emittance growth

April 6955

7615

7611

7612-14Changes toEnd of squeeze

AEM D. StillTevatron Issues and Operations 6

Losses at B0 (LMB1SD) in squeeze

QuenchStores last April

Current stores

AEM D. StillTevatron Issues and Operations 7

Losses at C0 (LMC4SM) in squeeze

QuenchStores last AprilCurrent stores

AEM D. StillTevatron Issues and Operations 8

Pbar Losses at D0 (LMC492) in squeeze

Quench

Stores last April

Current stores

AEM D. StillTevatron Issues and Operations 9

Compare Pbar beam loss in the Squeeze

current

Last April

AEM D. StillTevatron Issues and Operations 10

Compare Proton beam loss in the Squeeze

current

Last April

AEM D. StillTevatron Issues and Operations 1111

Studies/Work Completed

• Separator scans MOS store 7606- D0 lum increased ~2% and CDF/D0 ratio went from ~5% to 3%

• Lowered Pbar tunes at lbseq 25 (due to Scalloping)

• Evened out S7 table at lbseq 21-24.

• B0 VANG bumps lbseq[2-24] to explore B0 pipe aperture.

AEM D. StillTevatron Issues and Operations 12

Test of air flow from D0 hall to tunnel and possible Lowbeta Quad roll

Turned on fanin tunnel.

D0 IP pos moved By ~ 100 um.

Orbit stabilizationChanged HC49 by ~ 2amps

Possible for orbit errors Store to store

D0 X IP Pos

HC49

AEM D. StillTevatron Issues and Operations 13

Separator Scan CDF/D0 Lum ratio

•Separator scans MOS store 7606

•D0 lum increased ~2%

•CDF/D0 ratio went from ~5% to 3% difference.

Sept 2009

CDF/D0 Lum ratio

CDF Lum

AEM D. StillTevatron Issues and Operations 14

Summary

• Tevatron has requested lower pbar intensities ~ 400E10 to shoot from based on losses around B0 during the early squeeze.

• Tevatron currently has pbar vertical emittance growth at the end of the low beta squeeze and initiate collisions which is effecting initial luminosity.