Antiproton Acceptance

1. Antiproton Acceptance Two Projects: • High Gradient Lithium Lens • AP2 Beamline and Debuncher Acceptance Improvements Steve Werkema

2. Antiproton AcceptanceBasic Layout • Scope of Antiproton Acceptance projects: • Target station - downstream of target • AP2 beamline • Debuncher ring Steve Werkema

3. Antiproton AcceptanceMotivation Increase the number of antiprotons collected from the target by: • increasing the gradient of the collection lens • increasing the admittance of the AP2 beamline and the Debuncher MARS model of`p phase space distribution at the center of the target Dp/p < 2.25%, contains only`p’s within acceptance of Li Lens Steve Werkema

4. 29 cm 81cm 3° Pulsed Magnet Li Lens Target Antiproton AcceptanceHigh Gradient Lithium Lens - Parameters Steve Werkema

5. Antiproton AcceptanceHigh Gradient Lithium Lens - Motivation • 10% increase in`p yield by raising the gradient from 745 T/m to 1000 T/m • Factor of 2.3 increase in`p yield by raising the gradient to 1000 T/m and doubling the AP2/Debuncher Admittance Note: The`p yield improvement per gradient increase is greater at larger admittances Steve Werkema

6. Antiproton AcceptanceHigh Gradient Lithium Lens – Present Performance With the present design, the gradient would have to be lowered to 700 T/m to achieve a lifetime of 10,000,000 pulses. Steve Werkema

7. Antiproton AcceptanceHigh Gradient Lithium Lens – Goals & Action Plan • Goal:Operate a Lithium lens -- • at a gradient of at least 1000 T/m • for at least 10 million pulses • ActionPlan(in process for past 5 years): • Liquid Li Lens development at BINP • Improvement to present design • FEA model of present design • Autopsies of failed lenses • New solid Li Lens design Steve Werkema

8. Antiproton AcceptanceHigh Gradient Lithium Lens – Present Li Lens Steve Werkema

9. Antiproton AcceptanceHigh Gradient Lithium Lens – Status • Liquid Lithium Lens development Project terminated in FY 2002 without producing a viable lens prototype. • Existing Lens improvements • FEA: Peak stresses during lens operation are well below the fatigue strength of the titanium septum  failure initiated by another mechanism • Autopsies of five failed lenses: • 4 septum fractures, 1 water leak (control) • Preliminary analysis suggests that cracking had been initiated prior to pulsing the lens • Result: Improved quality control during fabrication of new lenses Steve Werkema

10. Antiproton AcceptanceHigh Gradient Lithium Lens – New design Features: • Diffusion bonded titanium body • Thicker septum • Li buffer volumes eliminated Prototype #1 is under construction Steve Werkema

11. Antiproton AcceptanceHigh Gradient Lithium Lens – Near Future • Complete and test new lens design prototype #1 • Lens #22 autopsy Longest lived lens, did not fail during pulsing • Refine and expand FEA model • Operate a lens constructed with improved quality control procedures Operate for 1 month at 745 T/m then increase to 820 T/m • Construct 2 new lenses with a thicker septum (20% – 50% thicker) Steve Werkema

12. Antiproton AcceptanceAP2 & Debuncher Acceptance – Motivation `p phase space distribution exiting the lens for a gradient of 750 T/m. Dp/p < 2.25% Beamline optics have been adjusted to match Li lens aperture. Blue dots are horizontal, Red dots are vertical (i.e. 2 points per`p). Goal: 40 p mm-mrad transverse admittance Steve Werkema

13. Antiproton AcceptanceAP2 & Debuncher Acceptance – Parameters Steve Werkema

14. Antiproton AcceptanceAP2 & Debuncher Acceptance – Issues • Identification of limiting apertures • Correction of known limiting apertures • Beamline element alignment • Orbit control • More AP2 trim dipoles • Debuncher moveable quad stands • Element redesign • Instrumentation issues • BPMs Steve Werkema

15. Antiproton AcceptanceAP2 & Debuncher Acceptance – Status The following projects are presently underway: • AP2 and Debuncher documentation survey (TD) Determine physical aperture everywhere in beamline from drawings and other documentation • AP2 line trim dipoles 3 NDB dipole trims have been installed in the AP2 line during the past year • Install moveable stands on selected Debuncher quads Cables were pulled during the January 2003 shutdown. No new stands have been installed. • Beam studies 88 Hours of beam studies in past year (next slide) • Debuncher BPM upgrade • Have completed beam testing of a single BPM electronics prototype • One sector of the Debuncher was instrumented during the January 2003 shutdown with upgraded BPM electronics Steve Werkema

16. Antiproton AcceptanceAP2 & Debuncher Acceptance – Completed Studies Beam studies completed within the past year • Reverse proton studies • Re-commission and develop various beam manipulation procedures (Debuncher, AP2, DRF3, DRF1) (36 hr) • Problem: have not yet been able to see beam on AP2 BPMs • Debuncher BPMs (Re-commission old electronics and prototype testing of new electronics) (8 hr) • Aperture measurements (4 hr) • Stacking studies • AP2 line orbit correction (12 hr) • Measure AP2 + Debuncher admittance (develop measurement techniques) (20 hr) • Measure AP2 + Debuncher momentum aperture (8 hr) Steve Werkema

17. Antiproton AcceptanceAP2 & Debuncher Acceptance – The Future • Complete documentation survey • Complete Debuncher BPM upgrade • Install Debuncher moveable quad stands • Build prototype portable quad alignment device • Element redesign • Beam Studies • Commission new hardware • Develop procedures (upgrade and test software & controls) • Correct AP2 and Debuncher orbits Note: much of the studies plan requires the new Debuncher BPMs and/or completed installation of the moveable quad stands. Steve Werkema

18. Antiproton AcceptanceConclusion Present`p yield: 1710-6`p/POT Expected`p yield: 4010-6`p/POT  36 1010`p/hr delivered to the Accumulator for stacking For: 51012 POT/pulse 2.0 sec cycle time Steve Werkema