# Presentation: 035507

## Pbar Production Status & Plans to get to 25mA/hr              

**Keith Gollwitzer**
**Antiproton Source**
**August 31, 2006**

## Motivation...

- Why am I here?
- Rob asked nicely with a pizza bribe!
- Why did CDF ask?
- McGinnis slides @ Feb. PMG
- I re-showed slides @ Apr. Acc. Div. Seminar
- Why pursue Stacking Rate?
- More pbars  greater Luminosity
- Fill Recycler faster
- Shorter stores with higher average luminosity
- Total integrated luminosity increases

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Statements

- The statement of interest for this talk
- “25 mA/hr by September”
- Another statement that is true
- “Pbar source is not back to 20mA/hr”
- Working on both

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Shutdown & Recovery

- Shutdowns allow for planned changes
- Character of systems change in unexpected ways
- P1 BPMs now sensitive to 424MHz from beam signal

*Expect blob or line*
*No changes to system*

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## What is Pbar still looking at?

- Beam line orbit stability
- “Oscillation Overthruster” and ellipses
- Work around(s) while Low Pass filters are purchased
- Momentum cooling systems
- Debuncher system shows to be 10-15% wider on Accumulator injection orbit
- Stacktail system had medium level plate replaced; gains and phases are still being adjusted
- Core Systems
- 4-8GHz had coax cable replaced by fiber
- Adjusting relative gains between 2-4GHz and 4-8GHz

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Performance since May

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## February’s “Future Pbar Work”

- Slip Stacking (7%)
- Currently at 7.5x1012 on average
- Design 8.0x1012 on average
- Lithium Lens (0 – 15%)
- Lens Gradient from 760T/m to 1000 T/m
- AP2 Line (5-30%)
- Lens Steering
- AP2 Steer to apertures
- AP2 Lattice
- Debuncher Aperture (13%)
- Currently 30-32 mm-mrad
- Design to 35 mm-mrad

- DRF1 Voltage (5%)
- Currently running on old tubes at 4.0 MEV
- Need to be at 5.3 MeV
- Accumulator and D/A Aperture (20%)
- Currently at 2.4 sec
- Design to 2.0 sec
- Stacktail Efficiency
- Can improve core 4-8 GHz bandwidth by a factor of 2
- Timeline Effects
- SY120 eats 7% of the timeline

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## DRF1

- The problem had been that the PA tubes were getting old and delivery had been delayed.
- A full set of PAs arrived during the shutdown and now have 5.6MV.

- DRF1 Voltage (5%)
- Currently running on old tubes at 4.0 MEV
- Need to be at 5.3 MeV
- Accumulator and D/A Aperture (20%)
- Currently at 2.4 sec
- Design to 2.0 sec
- Stacktail Efficiency
- Can improve core 4-8 GHz bandwidth by a factor of 2
- Timeline Effects
- SY120 eats 7% of the timeline

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Slip Stacking

- Slip Stacking (7%)
- Currently at 7.5x1012 on average
- Design 8.0x1012 on average
- Lithium Lens (0 – 15%)
- Lens Gradient from 760T/m to 1000 T/m
- AP2 Line (5-30%)
- Lens Steering
- AP2 Steer to apertures
- AP2 Lattice
- Debuncher Aperture (13%)
- Currently 30-32 mm-mrad
- Design to 35 mm-mrad

- Booster took sometime to get back to providing the intense beam after the shutdown.
- Main Injector is handling the beam quite well.
- Only the last few weeks have been at 8x1012.
- Quality is good – bunches could be a little shorter.

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Debuncher Aperture

- Slip Stacking (7%)
- Currently at 7.5x1012 on average
- Design 8.0x1012 on average
- Lithium Lens (0 – 15%)
- Lens Gradient from 760T/m to 1000 T/m
- AP2 Line (5-30%)
- Lens Steering
- AP2 Steer to apertures
- AP2 Lattice
- Debuncher Aperture (13%)
- Currently 30-32 mm-mrad
- Design to 35 mm-mrad

- During the shutdown only the Extraction Kicker stand was motorized.
- During startup admittances measured 33  mm-mrad.
- No work was done to optimize orbit/aperture with reverse protons.
- Extraction kicker stand centered on stacking beam mid-June

**Extraction Kicker beam tube was meant to be replaced during shutdown; vendor problem.**
**Hope for delivery by end of year**
**Installation is expected to be < 5days**
**	****Look for opportunity or**
**	****Schedule or**
**	****Next long shutdown**
**5% increase acceptance for large  ****Δ****p/p antiprotons**

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Stacktail & Core Systems

- 4-8GHz core system had a coax cable replaced by fiber increasing the bandwidth as well as an attenuator removed to allow more gain.
- Stacktail medium plate was replaced during the shutdown. Now gain settings are different than before.
- There are many gain knobs and phases to setup the systems.

- DRF1 Voltage (5%)
- Currently running on old tubes at 4.0 MEV
- Need to be at 5.3 MeV
- Accumulator and D/A Aperture (20%)
- Currently at 2.4 sec
- Design to 2.0 sec
- Stacktail Efficiency
- Can improve core 4-8 GHz bandwidth by a factor of 2
- Timeline Effects
- SY120 eats 7% of the timeline

**Much work to be done here to find the best setup.**
**Measurements are/will be made to see how to get to the higher rates beyond the current system: bandwidth, notch filters, dynamic range, S/N....**

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## AP2 Orbit

- Slip Stacking (7%)
- Currently at 7.5x1012 on average
- Design 8.0x1012 on average
- Lithium Lens (0 – 15%)
- Lens Gradient from 760T/m to 1000 T/m
- AP2 Line (5-30%)
- Lens Steering
- AP2 Steer to apertures
- AP2 Lattice
- Debuncher Aperture (13%)
- Currently 30-32 mm-mrad
- Design to 35 mm-mrad

- During the shutdown, two additional trims were added to line.
- To make progress requires long periods of stability of the 120GeV proton beam (Osc. Overthruster). BPM problems and needing to ask for “hours” while having pbar hungry customer.
- Software progress has been great and awaits testing.

**Low pass filter solution is near at hand**
**Ready to go forward with testing.**
**Will need to set program of many hours of watching the software run and make adjustments**

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Lithium Lens

- Slip Stacking (7%)
- Currently at 7.5x1012 on average
- Design 8.0x1012 on average
- Lithium Lens (0 – 15%)
- Lens Gradient from 760T/m to 1000 T/m
- AP2 Line (5-30%)
- Lens Steering
- AP2 Steer to apertures
- AP2 Lattice
- Debuncher Aperture (13%)
- Currently 30-32 mm-mrad
- Design to 35 mm-mrad

- Problem has always been balance between lens production and lens lifetime as a function of gradient
- New diffusion bonded lenses have been made. 8mm tested and used during the Fall. Nominal 10mm improved design and has been tested and is being installed on target station module.

**10mm lens will be the next one installed if the next lens failure does not occur in the next few weeks.**
**Will slowly increase gradient and have to make AP2 optics adjustment to match **
**Minimally expect longer lasting lens**

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Accumulator & D/A Aperture

- V. Lebedev is looking at redesigning the Accumulator and D/A optics.
- The Acc optics were cobbled together 7 years ago.
- The D/A matches on paper.
- D/A BPMs is current project.

- DRF1 Voltage (5%)
- Currently running on old tubes at 4.0 MEV
- Need to be at 5.3 MeV
- Accumulator and D/A Aperture (20%)
- Currently at 2.4 sec
- Design to 2.0 sec
- Stacktail Efficiency
- Can improve core 4-8 GHz bandwidth by a factor of 2
- Timeline Effects
- SY120 eats 7% of the timeline

**This will require lots of study time and I don’t see starting this until winter**
**First need to center beam in the quad centers with reverse protons and then optimizing the aperture.**
**Next implement optics change; probably several iterations.**
**Optimize stacking/cooling systems with new optics**

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Timeline

- Was not present for awhile.
- Now run 12hr/day and want primetime; successfully set SY run 0600-1800
- Pbar people have been taking advantage after 1800 to tune
- Mid-Sep, SY goes off for 3 months.
- Come back??
- Running conditions???????

- DRF1 Voltage (5%)
- Currently running on old tubes at 4.0 MEV
- Need to be at 5.3 MeV
- Accumulator and D/A Aperture (20%)
- Currently at 2.4 sec
- Design to 2.0 sec
- Stacktail Efficiency
- Can improve core 4-8 GHz bandwidth by a factor of 2
- Timeline Effects
- SY120 eats 7% of the timeline

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## The Pessimistic Slide

- Loss of people
- P. Derwent to Recycler
- B. Drendel to Run Coordinator
- E. Harms to RF cavity building
- D. McGinnis to the skies
- FY06 DoE Goal:
**INTEGRATE**
- People on summer vacation
- Stacktail and Accumulator optics will not be easy

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## The Optimistic Slide

- J. Morgan is back in the department
- V. Lebedev is interested and has plenty of ideas
- Derwent and McGinnis are consulting
- Summer is over
- No more vacations
- Run better as weather cools
- The pbars are there to be collected

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006

## Summary

- Stacktail, Stacktail, Stacktail, Core Cooling
- I believe the flux is getting into the Accumulator
- Inadvertent studies
- Booster studies went down to 2x1012 on target
- Stack rate decreased by a factor of 2.6
- Shots to Tevatron changes average stack cycle from nominal to 4.3s to 5s to 6s (tune-up, protons, pbars)
- By ratio of stack cycle time should be at goal
- Finding the correct setup.
- Orbit stability means easier to understand other studies and tuning

- Gollwitzer -- Pbar Production to 25mA/hr

- Aug 31 2006