Pbar Production Status & Plans to get to 25mA/hr Keith Gollwitzer Antiproton Source August 31, 2006

Aug Gollwitzer -- Pbar Production to 25mA/hr2 Motivation… Why am I here? –Rob asked nicely with a pizza bribe! Why did CDF ask? –McGinnis Feb. PMG –I re-showed 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

Aug Gollwitzer -- Pbar Production to 25mA/hr3 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

Aug Gollwitzer -- Pbar Production to 25mA/hr4 Shutdown & Recovery Shutdowns allow for planned changes Character of systems change in unexpected ways –P1 BPMs now sensitive to 424MHz from beam signal 1 st Vertical BPM Other P1 BPMs 8 th H 7 th H 5 th V 2 nd V Expect blob or line No changes to system

Aug Gollwitzer -- Pbar Production to 25mA/hr5 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

Aug Gollwitzer -- Pbar Production to 25mA/hr6 Performance since May

Aug Gollwitzer -- Pbar Production to 25mA/hr7 February’s “Future Pbar Work” Slip Stacking (7%) –Currently at 7.5x10 12 on average –Design 8.0x10 12 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  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

Aug Gollwitzer -- Pbar Production to 25mA/hr8 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

Aug Gollwitzer -- Pbar Production to 25mA/hr9 Slip Stacking Slip Stacking (7%) –Currently at 7.5x10 12 on average –Design 8.0x10 12 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  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 8x Quality is good – bunches could be a little shorter.

Aug Gollwitzer -- Pbar Production to 25mA/hr10 Debuncher Aperture Slip Stacking (7%) –Currently at 7.5x10 12 on average –Design 8.0x10 12 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  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 Δp/p antiprotons

Aug Gollwitzer -- Pbar Production to 25mA/hr11 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….

Aug Gollwitzer -- Pbar Production to 25mA/hr12 AP2 Orbit Slip Stacking (7%) –Currently at 7.5x10 12 on average –Design 8.0x10 12 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  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

Aug Gollwitzer -- Pbar Production to 25mA/hr13 Lithium Lens Slip Stacking (7%) –Currently at 7.5x10 12 on average –Design 8.0x10 12 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  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

Aug Gollwitzer -- Pbar Production to 25mA/hr14 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

Aug Gollwitzer -- Pbar Production to 25mA/hr15 Timeline Was not present for awhile. Now run 12hr/day and want primetime; successfully set SY run 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

Aug Gollwitzer -- Pbar Production to 25mA/hr16 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

Aug Gollwitzer -- Pbar Production to 25mA/hr17 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

Aug Gollwitzer -- Pbar Production to 25mA/hr18 Summary Stacktail, Stacktail, Stacktail, Core Cooling –I believe the flux is getting into the Accumulator Inadvertent studies –Booster studies went down to 2x10 12 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