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Antiproton Acceptance. Two Projects: High Gradient Lithium Lens Project Leader: Jim Morgan AP2 Beamline and Debuncher Acceptance Improvements Project Leader: Keith Gollwitzer. Antiproton Acceptance Basic Layout. Scope of Antiproton Acceptance projects: Target station - downstream of target
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Antiproton Acceptance Two Projects: • High Gradient Lithium Lens Project Leader: Jim Morgan • AP2 Beamline and Debuncher Acceptance Improvements Project Leader: Keith Gollwitzer Steve Werkema
Antiproton AcceptanceBasic Layout • Scope of Antiproton Acceptance projects: • Target station - downstream of target • AP2 beamline • Debuncher ring Steve Werkema
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
29 cm 81cm 3° Pulsed Magnet Li Lens Target Antiproton AcceptanceHigh Gradient Lithium Lens - Parameters Steve Werkema
V. Lebedev October 2001 Antiproton AcceptanceHigh Gradient Lithium Lens - Motivation • 12% increase in`p yield by raising the gradient from 745 T/m to 1000 T/m • Factor of 2.1 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
Antiproton AcceptanceHigh Gradient Lithium Lens – Present Performance Operation at gradients greater than 745 T/m significantly degrades the lifetime of the lens. Steve Werkema
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 • Improve present Li Lens design • FEA model of present design • Autopsies of failed lenses • Better measurement & control of Li pre-load • New solid Li Lens design (began 2000) Steve Werkema
Antiproton AcceptanceHigh Gradient Lithium Lens – Present Li Lens Steve Werkema
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
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
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
Antiproton AcceptanceAP2 & Debuncher Acceptance – Motivation `p phase space distribution exiting the lens for a gradient of 750 T/m. Dp/p < 2.25% Blue dots are horizontal, Red dots are vertical (i.e. 2 points per`p). Note: the 20 p and 40 p ellipses represent two different AP2 lattices. The AP2 optics has been adjusted to match Li lens aperture. Goal:35 p mm-mrad transverse admittance Steve Werkema
V. Lebedev November 2001 Antiproton AcceptanceAP2 & Debuncher Acceptance – AP2 Lattice Steve Werkema
Antiproton AcceptanceAP2 & Debuncher Acceptance – Parameters †There are several locations where the physical aperture is known to be less than the admittance indicated in this table (e.g. Band 4 cooling pickups and kickers, Debuncher quadrupole D4Q4, DRF2 and DRF3 cavities). Steve Werkema
Antiproton AcceptanceAP2 & Debuncher Acceptance – Scope • Identification of limiting apertures • Technical Division documentation and drawing survey • Optical survey and alignment • Beam studies • LBL focus on Debuncher Injection Channel • 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
V. Lebedev November 2001 Antiproton AcceptanceAP2 & Debuncher Acceptance – AP2 Aperture Beam envelopes in AP2 line for an admittance of 40 p mm-mrad. Aperture limitations are shown by the vertical lines extending from the top of the plot. Synchrotron size is shown for an energy spread of 2.5%. The aperture information in this plot is incomplete and somewhat out of date. Updated information is being developed by the Tech. Div. Documentation and drawing survey. Steve Werkema
Antiproton AcceptanceAP2 & Debuncher Acceptance – Status (1) The following projects are presently underway: • AP2 and Debuncher documentation survey (Tech. Div.) Determine physical aperture everywhere in beamline from drawings and other documentation. Expected completion: Fall 2003 • Optical Survey and Alignment Not yet started. Survey work will proceed as resources permit during maintenance and scheduled shutdowns. Expected completion: Fall 2003 • Instrumentation • AP2 BPMs • Presently unusable for reverse protons due to kicker ground surge • Relocation of BPM electronics – Estimated Completion: Fall 2003 • DAQ hardware & software upgrade – Estimated completion: Fall 2004 • Debuncher BPM upgrade • One sector (1/6) of new electronics installed and being tested • Remaining 5 sectors to be installed during Summer 2003 shutdown • Completion of software development expected by Fall 2003 • Beam commissioning complete by mid 2004 Steve Werkema
Antiproton AcceptanceAP2 & Debuncher Acceptance – Status (2) Projects presently underway (continued): • Orbit Control • AP2 line trim dipoles • 4 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. • Install existing 10 stands in Summer 2003 shutdown • Install an additional 20 stands during Summer 2004 shutdown • Expected Completion: Fall 2004 • Critical examination of Debuncher injection channel (LBL – Ina Reichel, Mike Zisman, John Corlett) • Review of Debuncher injection design – propose upgrades • Develop beam based alignment procedures • Status: Work started in April 2003. Presently collecting documentation and developing optics model. Steve Werkema
Antiproton AcceptanceAP2 & Debuncher Acceptance – Status (3) Projects presently underway (continued): • Redesign/Relocation of Beam line components Aperture restrictions already identified: • Replace/modify band 4 stochastic cooling pickups and kickers • Replace quad D4Q4 • Move RF cavities DRF2 and DRF3 Steve Werkema
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) (40 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
Antiproton AcceptanceAP2 & Debuncher Acceptance – The Future • Complete documentation survey • Complete Debuncher BPM upgrade • Install Debuncher moveable quad stands • 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
Antiproton AcceptanceConclusion – What difference does it make? Present`p yield: 1610-6`p/POT Expected`p yield: 3610-6`p/POT 52 1010`p/hr delivered to the Accumulator for stacking For: 81012 POT/pulse (slip stacking) 2.0 sec cycle time Steve Werkema