# Presentation: 393758

## Week in Review: 02/10/03 –02/16/03

**  ****Ron Moore – FNAL**

- Store Summary – first stores after shutdown
- Schedule for Week

- All Experimenters' Mtg - 17 Feb 03

## Store Summary

| Store | Initial
Lumi | Deliv’d
Lumi | Termination | Comments |
| --- | --- | --- | --- | --- |
| 2194 | 4.5 | - | Quench | Abort kicker prefire(?) after 35 min |
| 2208 | 17.3 | 167 | Quench | A2 UPS fried, dropped QPM link after 3 hrs |
| 2213 | 20.9 | 698 | Intentional |  |
| 2229 | 18.5 | 536 | Intentional | Limiting proton intensity; no dampers |
| 2231 | 18.9 | 630 | Quench | F3 CC tripped few minutes before termination |
| 2232 | 16.8 | 556 | Intentional | Limiting proton intensity; no dampers |
| 2234 | 15.9 | 514 | Intentional | Limiting proton intensity; no dampers |

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

## Operations

- Booster tuned up well
- ~4.4 E12 protons per pulse on pbar target
- MiniBoone 2 E16 prot/hr with 7 turns @ 1.75 Hz
- Stacking well
- Max stacking rate ~ 10 mA/hr
- Rate dropping more quickly with stack size
- Stacktail cooling needs optimization
- Operationally stable putting in stores
- Luminosity isn’t great, but stores are going in smoothly and being ended intentionally
- Losses are acceptable
- Proton and pbar lifetimes at 150 GeV slightly better than before shutdown, even without new helix and dampers

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

## Why is luminosity so low?

- Before shutdown, typical   =  high 20’s – low 30’s
-  only in the teens now    lower proton and pbar intensities
- Why fewer pbars?
- Shooting from smaller stacks (120 mA vs 140 mA) since  low
- ARF 4 cavity used in unstacking can cause poor coalescing in MI
- ~30% fewer pbars at collisions than pre-shutdown
- Why fewer protons?
- Quenching at B38 early in ramp
- Related to chromaticity and/or DC beam being lost there?
- Aperture scan showed no restriction
- To get through the weekend, limited proton intensity and used TEL to remove DC beam injecting pbars
- ~20-25% fewer protons at collisions than pre-shutdown

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

## Not-so-good pbars in Store 2232

- 60% coalescing eff in MI

- AP-1 wall monitor

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

## Better pbars in Store 2232

- 86% coalescing eff in MI

- AP-1 wall monitor

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

## B38 Loss Up Ramp- Store 2232

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

## Maintenance / Studies This Week

- 5 shifts of dedicated maintenance/studies
- Get back to pre-shutdown proton and pbar intensities!
- Pbar
- Access tomorrow to partially retreat on ARF 4 cavity impedance increase made in shutdown
- Other minor repairs
- Tevatron
- Understand the B38 loss
- Measure proton instabilities – lower chromaticity
- Commission E17 Schottky
- Test, but not implement, new injection helix

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

## Weekly Schedule

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03

## Summary

- Resumed normal Collider operation after shutdown
- Stable operation for stacking and making stores, but luminosity ~ factor 1.5-2 low than pre-shutdown
- Proton intensity 20-25% lower to prevent B38 quench on ramp
- Pbar intensity ~30% lower due to diminished pbar coalescing efficiency (retreat on pbar unstacking cavity impedance change)
- 5 shifts of dedicated maintenance/studies this week
- Lower ARF 4 impedance a bit to help improve pbar coalescing
- Control proton loss @ B38 to increase proton intensity
- Resume “stack and store” through the weekend

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Feb 03