# Presentation: 219029

## Week in Review: 3/10/03 – 3/16/03

**  ****Ron Moore – FNAL**

- Store Summary
- Record Store #2318
- Chronic High Proton Losses @ CDF
- Explanation of Tevatron Coupling
- Schedule for Week

- All Experimenters' Mtg - 17 Mar 03

## Store Summary

| Store | Initial
Lumi | D0 Deliv’d
Lumi | Termination | Comments |
| --- | --- | --- | --- | --- |
| 2307 | 31.8 | 443 | Abort | 1st store after shutdown; transverse + longitudinal dampers ON; B0Q5 VFC failure |
| 2312 | 29.4 | 1064 | Intentional | High CDF proton halo losses |
| 2309 | 18.8 | 484 | Intentional | Poor pbar coalescing due to not restoring changes after studies; end-of-store studies to pursue high losses at start of store |
| 2315 | 35.1 | 1298 | Intentional | Shot from 120 mA; high CDF proton losses |
| 2318 | 40.6 | 134 | Abort | Shot from 149 mA; high CDF proton losses; store lost while trying to tune on losses  |
| 2321 | 34.3 | - | ongoing | Shot from 133 mA; high losses again |

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Record Store #2318

- Store #2318:  = 40.6 E30
- Previous best #1953:   = 36.9 E30

|  | 1953 | 2318 |
| --- | --- | --- |
| Protons @ HEP (E9) | 5873 | 7411 |
| Pbars @ HEP (E9) | 907 | 902 |
| Calculated Transverse Emit. | 17.2 | 19.8 |

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Recent Improvements

- Last few stores among highest initial luminosity
- Increased proton intensity
- Better lifetime on helix @ 150 GeV  (> 3 hrs)
- No sign of instability
- 7200-7400 E9 protons at start of store   (up from 6400-6600)
- ARF4 cavity restored to pre-shutdown condition
- Reliable pbar extraction  improved pbar coalescing
- Average pbar coalescing now > 85% ;  efficiency to HEP  ~65%
- 800- 900 E9 pbars at start of store   (up from 500-600)
- Want to try bigger stacks   (#2138 shot from 150 mA)
- Keep protons at current levels until high losses understood better

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Slide 5

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Slide 6

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Slide 7

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Slide 8

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## FY03 Integrated Luminosity and Plan

- _FY03 Integrated Luminosity and Plan_

**stretch**

**base**

**Base = 0.625 * Stretch**

- As of today:   Stretch  127 pb-1     Base  80 pb-1      Actual  88 pb-1

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Chronic High Proton Losses @ CDF

- Very large proton background at CDF since A1 work
- Has required several hours each store to get losses down to level acceptable for silicon system
- Some tuning, some waiting...no magic bullet
- D0 losses OK, typically proportional to proton intensity
- CDF much more sensitive to working point, collimators
- Will pursue collimator alignment, aperture scans, additional tune, coupling tweaking

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Store 2264

- CDF Proton Halo  (Hz)

- Store 2315

- Proton Intensity
- (E9)

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Explanation of Tev Coupling

- Some history...Don Edwards noticed global skew quad circuit SQ running a lot harder in Run II than in Run I
- Rolled quads not enough to explain the difference
- Mike Syphers found coupling @ 150 GeV can be explained by distributed skew quad elements around ring
- All dipoles have skew quad component   _a__1 __~10__-4__ / inch_
- Dipole coil sag within iron causes skew quad component
- TD personnel measured “smart bolts” on some Tev dipoles
- Coils sagged few (4-6) mils
- G11 blocks at ends of bolts have shrunk via compression
- Mike Syphers calculated the a1 component in such a sagging coil magnet
- For bolts 6 mils inward, coil sags by 4.2 mils      _a__1 __= 1.1__ __10__-4__ / inch_
- What do we do about it?
- Probably nothing...global skew quads compensating OK...sag has reached its max
- Repeat orbit measurements with SQ on and look for sources of local coupling

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Coupling Study @ 150 GeV

- Beam missteered in P1 line
- T:SQ  global skew quad circuit at 0 amps
- Look at betatron oscillations coupling between horz & vert
- Below are ~ 4 turns of data;  1st turn on left;   scale limits   4mm

- Horizontal

- Vertical

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Tevatron Dipole 

- Tevatron Dipole

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Weekly Schedule

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Sources of Downtime

- Proton Source
- Two failing Linac PAs necessitated swap/replacement
- Spare  LRF4,    LRF4  LRF1,    LRF1  out
- Still have BNL tube as an emergency spare
- New tube from Burle delayed again (vacuum issues)
- Booster ORBMP water leak Friday evening
- Repaired leak – replaced soggy and shorted components
- Tevatron
- D0QT2 (low  quad trim magnet) supply caused quenches on Sat and Sun evening

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03

## Summary

- Store #2318 record  = 40.6 E30
- Lost while tuning to reduce high CDF proton losses
- Tevatron running well overall recently
- 2 Linac PA tubes replaced/swapped last week
- Only have emergency spare from BNL
- Sagging coils in Tev dipoles explains coupling and why global skew quads run as hard as they do
- Stack & Store this week
- Pursue CDF high proton losses with HEP stores and dedicated time if needed

- R. Moore - FNAL

- All Experimenters' Mtg - 17 Mar 03