# Presentation: 246665

## Week in Review: 12/16/02 -12/22/02

**  ****Ron Moore – FNAL**

- Store Summary (Studies Week)
- Studies Review
- Schedule for Week

- All Experimenters' Mtg - 23 Dec 02

## Store Summary

| Store | Initial
Lumi | CDF Deliv’d
Lumi | Termination | Comments |
| --- | --- | --- | --- | --- |
| 2078 | 28.4 | 1229 | Intentional | Proton bunch length blow-up at 980 GeV |
| 2087 | 22.9 | 894 | Intentional | New feeddowns implemented @ 150 GeV |
| 2090 | 27.9 | - | Abort | Safety system dropped power supplies for 7 sec
Bad UPS? |
| 2091 | 24.8 | 827 | “Intentional” | Longitudinal dampers cause proton blow-up;
TEL failure;   proton removal study |
| 2094 | 32.6 | 750 | Abort kicker prefire | Horz and vert dampers ON @ 150 GeV; 
longitudinal damper OFF |
| 2097 | 29.5 | - | ongoing | Horz and vert dampers ON @ 150 GeV; 
longitudinal damper OFF |

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Slide 3

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Slide 4

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Recycler Pbar Shots

- Stack to 30 E10 following HEP shot, then shoot to RR
- 5 opportunities since 12/16
- 1 cancelled due to losing TeV store #2090 early
- Lots of small pilot shots on first try
- Usually 1 or 2 shots in subsequent attempts
- Initial goal is to streamline shot procedure
- Only 2 individual transfers “failed” – no beam unstacked in Acc.
- Time of no stacking ~ 60-65 minutes
- 2 shots delayed by Booster, MI problems during setup
- Average transfer efficiency 60%
- Leaving 10% beam in MI – need to improve coalescing
- Shots successful overall – still learning and adjusting to minimize impact on Tevatron operations

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Tevatron Studies

- Adjusted feeddowns @ 150 GeV to improve decoupling
- Minimum horizontal, vertical tune split < 0.002 on both helices
- Chromaticity on proton helix 2 units larger than before
- Can now run both horizontal, vertical transverse dampers to allow lower chromaticities to improve lifetimes
- Pbars lost @ 150:  Store 2078 – 15%      Store 2097 – 8 %
- Pbar removal to compare flying wire / synch light monitor
- Try to understand differing emittances from the two systems
- TEL removed 30 pbar bunches, then vert collimator scraped rest
- Initial flying wire emittance high (43 vs 20-24  expected)
- Sync light had significant offset 12-18 when essentially no beam
- Measure transverse impedance of C0 lambertson
- Lambertsons now thought to be large source of impedance (up to  5 M/m) and strong head/tail instability

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Hardware Problems Friday-Sunday

- Lost store #2090 due to safety system – bad UPS
- Longitudinal damper blew-up proton bunch length  (store #2091)
- Losses in abort gap grow – CDF turned off Si
- TEL failed as abort gap losses began to decrease    (store #2091)
- First replaced melted capacitor array
- Then found water leak
- Required tunnel access and 8 hours to repair
- Booster extraction kicker MP02 regulator failed
- Related to elevated temperature in Booster gallery?
- Required a few hours to finally understand, replace chassis
- Booster injection Lambertson supply failed  (only ~1 hour down)
- Proton abort kicker prefire ended store #2094
- Got lucky with timing – almost in abort gap
- No additional damage to CDF Si
- Conditioned all 10 thyratron tubes for 6 hours

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Blow-up

- TEL failure
- begins

- Proton removal

**Store #2091**

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Blow-up

**Store #2091**

- Abort gap
- losses grow

- Abort gap
- losses decrease
- when damper off

- TEL failure
- begins

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Other happenings this past week

- Shutdown Tuesday > 1 shift
- Tevatron surveys for C0 lambertson,  magnet rolls
- Main Injector (4.5 hours) and Tevatron safety system tests
- Cryo maintenance
- Electrical/power supply maintenance
- Various tunnel tours in preparation for January shutdown
- Completed safety system tests after store #2090 lost
- 3 hour Tev test + collision halls
- No need for variance to extend grace period
- No need to shutdown to complete tests
- Impromptu proton removal study at end of store #2091
- Needed to scrape beam anyway to eliminate DC beam without TEL
- First time for proton removal without quench
- Took more than 2.5 hours, but gained valuable info on removal process and flying wire, sync light comparison

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02

## Summary

- Various hardware failures:  only delivered _3.7 pb__-1_
- Completed safety system tests whose grace period expiring
- “Fast” Recycler pbar shots progressing well
-  Tevatron transverse dampers on @ 150 GeV
- Continue to improve lifetimes, leading to better luminosity
- This week is stack and store.
- These talks available on the web via:
- http://www-runii.fnal.gov/RunCoord/RunCoord.htm

- R. Moore - FNAL

- All Experimenters' Mtg - 23 Dec 02