Gollwitzer Antiproton

Antiproton Source Status: 

Antiproton Source Status Keith Gollwitzer All Experimenters’ Meeting June 18, 2007

Targets: 

Targets Module damaged before completely used Current target should last to Shutdown

Lithium Lens & Transformers: 

Lithium Lens & Transformers Old version (Steel Body) - failures Lens due to lithium breach at welds Transformer – radiation damage (around 4e19 protons) New version (Titanium Body; 8mm or 10mm) – Higher Gradient History Spares: Unused: Steel Body 31; 8mm-2 (problem during filing; should work) Previously used: 23 (replace transformer); 4 (21 and 12 years ago)

Transformers: 

Transformers New style transformers starting with lens 10mm-2 have ceramic instead of kapton for insulation. Also, the water cooling has moved from outside of transformer to inside. Leak of lens water system near the frame corner appears to have sprayed the transformer. Dry out; fix fault; fix leak; shower curtain Old New Leak

Pulsed Magnet: 

Pulsed Magnet From 2002 to 2005; service was 1-2e19 Protons Record was 2.2e19 protons Included changes in design Last PMAG service 0.8e19 protons without collimator 1.7e19 protons with collimator Collimator located between lens and PMAG Current PMAG at 5.5e19 protons!!!! Picture in-situ 5/10/07 Ground Faulted 9/18/05

Target Station : 

Target Station Sweeping Magnets

Sweeping and Spot Size: 

Sweeping and Spot Size Original idea based upon belief target would melt for >5e12 protons on target Two magnets “sweep” 120GeV protons in circle prior to target Single magnet between Lens and PMAG to “unsweep” secondaries Current thought use tiny proton sweep only Trigger one pre-target magnet early Beam sees resonant tail and barely sweeps Appears to have decreased target depletion rate Furthermore, smaller spot size (180μm to 140μm) Less energy deposited per unit volume Smaller beam means better yield (4%) Still observing

AP2 and Debuncher: 

AP2 and Debuncher Orbit AP2: continue to work on parasitically Make adjustments when single BPMs change response Debuncher: reverse protons Recently trying to acquire beam during transfer tune-up Minimize impact of de-tuning RF cavities Acquired orbit Measured admittance Corrected vertical orbit

Accumulator : 

Accumulator Stacktail, Stacktail, Stacktail Moved one of the pickup tanks radially outward 5.8mm Changed distance between legs 2 and 3 wrt to core Allows leg 3 to be used More tuning knobs Changed Accumulator Lattice Considerations: Better phase advance between pickup and kicker Reduce transverse heating Not perfect cooling kickers Increase slip factor (η) Reduce beam size in apertures Re-tuning of Stacktail Reduced transverse heating New version of equalizer installed Reduced power needed to stack Reduced transverse heating Measurements done throughout Compare and develop model; still analyzing and tuning

Tuning leads to less drop-off: 

Tuning leads to less drop-off Stacktail Tuning

Decrease time transferring: 

Decrease time transferring

Performance: 

Performance

To Do: 

To Do Accumulator Aperture Achieved is much less than what is on paper Orbit work will require chunks of reverse protons D/A transfer line Instrumentation and Orbit work being done with reverse protons during transfer tune-up Will also do optics work to match with Debuncher and Accumulator Cooling Debuncher Keep power optimized (balancing, drift of TWTs, gain curves) Two-turn notch filter (switch in during cycle) Accumulator Core 4-8 new equalizier Optimization of stacktail and core systems