Antiproton Acceptance Steve Werkema February 8, 2005

Antiproton Acceptance – Steve Werkema 2 Goal Increase the number of antiprotons collected from the target by: 1) Increasing the admittance of the AP2 beamline and the Debuncher to 35  mm-mrad 2) Increasing the gradient of the collection lens to 100 kG/cm Note: Yield curves in model reduced by 10% to approximately account for chromatic effects 1.5 

Antiproton Acceptance – Steve Werkema 3 Progress So Far SD ‘03SD ‘04

Antiproton Acceptance – Steve Werkema 4 AP2 & Debuncher Acceptance † AP2 + Debuncher admittances reported at the Feb 2004 review were: Horizontal: 24  mm-mrad, Vertical: 18  mm-mrad * Debuncher admittances reported at the Feb 2004 review were: Horizontal: 28  mm-mrad, Vertical: 20  mm-mrad Most Recent Measured AP2 + Debuncher Most Recent Measured Debuncher Max. Measured Admittance AP2+Deb / Deb Smallest Known Aperture Goal Horizontal (mm-mrad) 24 ± 3  † 24 ± 3   30  33  36  35  Vertical (mm-mrad) 20 ± 2  † 21 ± 2   20  23  30  35  Momentum ±2.15%±2.30% --±2.25%

Antiproton Acceptance – Steve Werkema 5 The Plan Identify Limiting Apertures  Assemble Documentation and Drawings (FNAL Tech. Div.) (WBS )  Optical Survey and Alignment (WBS )  Improve AP2 and Debuncher Lattice models (WBS )  Beam based determination of limiting apertures (WBS ) Mitigate aperture restrictions  Redesign/modify/rebuild/relocate beamline elements (WBS )  DEX Bump  Chromatic correction of the AP2 beamline (LBNL)(WBS ) Implement Beam Based Alignment  Instrumentation upgrades (WBS ) AP2 BPMs Debuncher BPMs  Orbit control (WBS ) Install additional dipole trims in AP2 Motorized quad stands in the Debuncher  Beam Based Alignment (WBS ) Develop procedures Software development  Beam studies (WBS ) New

Antiproton Acceptance – Steve Werkema 6 Identification of limiting Apertures – Documentation, Survey Documentation and Drawings  AP2 & Debuncher Physical Aperture tables complete. Apertures have been incorporated into the lattice models.  Present activity consists of keeping these tables up-to-date Optical Survey  Survey data collection completed during Fall 2004 shutdown  Survey data analysis expected to be complete in March 2005

Antiproton Acceptance – Steve Werkema 7 Identification of limiting Apertures – Beam Based Methods Aperture Painting – Running Wave

Antiproton Acceptance – Steve Werkema 8 Identification of limiting Apertures – Beam Based Methods Bumping around the Debuncher Center moveable devices on beam. Build high precision Debuncher intensity monitor (D:BPI801). Construct 3- bumps that cover the Debuncher (43 horiz vert. bumps) During stacking, move each bump  2 mm while monitoring Debuncher intensity. Measured during Stacking

Antiproton Acceptance – Steve Werkema 9 Identification of limiting Apertures – Beam Based Methods Block diagram of intensity monitor  Status:  Intensity monitor is operational  Procedure verified  ½ of 3-bumps verified  Plan to enlist the assistance of operations crews to perform procedure. Pre-amp 1KHz switch Spectrum Analyzer Zero DRF1 Frequency Video Output Oscilloscope Signal External Trigger Front-end Linux Get Trace & Analyze Output ACNET BPM Intensity BPM Signal cable to upstairs

Antiproton Acceptance – Steve Werkema 10 Mitigation of Limiting Apertures  Debuncher injection region modifications  Move DRF2  Widen vertical band 4 stochastic cooling arrays  Debuncher extraction kicker upgrade  DEX Bump  Chromatic correction of the AP2 beamline  AP2 Beam stop Completed during the Fall 2004 shutdown Scheduled for the Fall 2005 shutdown Proposal complete by March 2005 (6 month delay) Removed/moved during Fall 2004 shutdown Est. completion: Spring 2005 New Extra Credit

Antiproton Acceptance – Steve Werkema 11 Mitigation of Limiting Apertures – Debuncher Injection Area Debuncher Injection Area Modifications:  Injection septum common vacuum  Replace D4Q4 SQC quadrupole with two LQB quadrupoles  Motorize injection septum and kicker stands  Vacuum system modifications oBigger D4Q4 vacuum chamber oMove BPM upstream of D4Q4

Antiproton Acceptance – Steve Werkema 12 Mitigation of Limiting Apertures – Debuncher Injection Area Old Layout Septum D4Q4

Antiproton Acceptance – Steve Werkema 13 Mitigation of Limiting Apertures – Debuncher Injection Area New Layout Septum D4Q4a D4Q4b

Antiproton Acceptance – Steve Werkema 14 Mitigation of Limiting Apertures – Debuncher Injection Area D4Q5 configuration AP2 D4Q5 Septum Circulating Beam

Antiproton Acceptance – Steve Werkema 15 Mitigation of Limiting Apertures – Debuncher Injection Area Injection Septum Common Vacuum

Antiproton Acceptance – Steve Werkema 16 Mitigation of Limiting Apertures – Debuncher Injection Area D4Q4 Aperture Old New Note: Injected and circulating beam are vertically separated here.

Antiproton Acceptance – Steve Werkema 17 Mitigation of Limiting Apertures – DEX Bump Debuncher Extraction Bump Purpose: To rapidly move beam close to the extraction septum late in the stacking cycle (after it has cooled) Status:  Two trim dipoles installed in Debuncher during the Fall 2004 shutdown  All cables to the tunnel have been pulled  Power supplies are being built by EE suppt. (est. completion: Feb. 2005)  Installation and testing of ramp controls (MDAT) (Feb. 2005)  Commissioning beam studies (March 2005)

Antiproton Acceptance – Steve Werkema 18 Mitigation of Limiting Apertures – Chromatic Correction Chromatic Correction of the AP2 Beamline Work being done in collaboration with LBNL  Model chromatic effects  Beam studies to test model  Propose correction scheme (March 2005) W Deb Debuncher Li Lens AP2 line chromatic  -functions

Antiproton Acceptance – Steve Werkema 19 Mitigation of Limiting Apertures – Chromatic Correction Normal Sextupole added to Q701, Q702, Q703, Q704; Q719, Q720 Skew Sextupole added to Q731, Q733 AP2 Lattice AP2 Chromatic Correction Scheme

Antiproton Acceptance – Steve Werkema 20 Mitigation of Limiting Apertures – Chromatic Correction Setup for adding a variable sextupole component to a quadrupole magnet Separately powering the left and right halves (or rotating the arrangement shown here by 90º) produces normal sextupole. Separately powering the upper and lower halves produces a skew-sextupole (shown here  ).

Antiproton Acceptance – Steve Werkema 21 Mitigation of Limiting Apertures – Chromatic Correction Measurements of integrated sextupole vs. average quadrupole excitation current for various differential excitation currents.

Antiproton Acceptance – Steve Werkema 22 Mitigation of Limiting Apertures – AP2 Beam Stop Mis-alignment of AP2 beam stop & beam pipe Beam stop Shielding Edge Beam 35  x 2.25%  p/p

Antiproton Acceptance – Steve Werkema 23 Mitigation of Limiting Apertures – AP2 Beam Stop Horizontal aperture after removal of AP2 beam stop

Antiproton Acceptance – Steve Werkema 24 Mitigation of Limiting Apertures – AP2 Beam Stop Yield to downstream end of AP2 line increased ~10% as a consequence of the removal of the AP2 beam stop. Plans: Plan to install new beam stop downstream of Q704 during the Fall 2005 shutdown.

Antiproton Acceptance – Steve Werkema 25 Yet to be Corrected Limiting Apertures * The numbers in this column were calculated using  -functions at  p/p = 0 Device Horizontal Vertical * Band 4 H pickup36.8  36.3  48.7  Band 4 V pickup40.5  39.0  29.9  Band 4 H kicker36.0  35.5  48.7  Band 4 V kicker41.2  41.1  30.1  Deb Extr. kicker  21.9  35.8  Central orbit (  p/p = 0) limiting apertures: Horizontal:36.0  mm-mrad Vertical:29.9  mm-mrad Combined effect of Band 4 and Extr. Kicker upgrades once these admittances are achieved is ~7.4% (from particle tracking). Not to be changed

Antiproton Acceptance – Steve Werkema 26 Yet to be Corrected Limiting Apertures  Vertical band 4 cooling pickup and kicker  Upgrade arrays during Fall 2005 shutdown  Likely requires 8 week shutdown  Debuncher extraction kicker  Presently evaluating the impact of the proposed aperture upgrade on field quality and load impedance.  Go/no-go decision in February 2005 (this month)  If this is a go, the upgrade will be installed during the Fall 2005 shutdown.

Antiproton Acceptance – Steve Werkema 27 Beam Based Alignment – Instrumentation Instrumentation  AP2 BPMs Deb. Extraction kicker noise issues resolved DAQ hardware & software upgrade – Est. completion: Mar  Debuncher BPMs All 6 sectors installed and operational Console software is functional and in routine use Orbit Control  Debuncher motorized quad stands All motorized quad stands have been installed (completed during Fall 2004 shutdown) Bumps for <1/3 of the ring have been used so far for aperture optimization Position 3-bumps for 1/2 of the ring have been verified

Antiproton Acceptance – Steve Werkema 28 Beam Studies Studies since the February 2004 review  Reverse proton studies Debuncher Orbit correction (in conjunction with running- wave aperture determination) Development of running wave aperture finding in the Debuncher AP2 BPM development studies Bump verification with new motorized quad stands Admittance measurement  Stacking studies Measure AP2 + Debuncher admittance Development of AP2 BBA using Debuncher TBT Study chromatic effects (momentum slicing experiments)  bumps in AP2 “Bump around” Debuncher – procedure development

Antiproton Acceptance – Steve Werkema 29 Beam Studies – How Beam Time was Spent

Antiproton Acceptance – Steve Werkema 30 Beam Studies – When we got the Time

Antiproton Acceptance – Steve Werkema 31 Beam Studies – Future Plans Reverse Proton Studies  Verify Debuncher 3-bumps (6 hr)  Align beam in Deb. injection channel (3 – 5 shifts)  DEX bump studies (2 – 4 hr)  Alignment of downstream end of AP2 line with new AP2 BPMs (3 – 4 shifts) Stacking Studies  DEX bump commissioning  Bump around Debuncher  Beam based alignment of AP2 with new BPMs

Antiproton Acceptance – Steve Werkema 32 Lithium Lens Upgrade Spare Prototype 1 Lenses  Building conventional spare first  First Prototype 1 lens complete by ~6/1/2005 New power supply for testing  Russian power supply  more difficult than expected  Increased support (K. Bourkland + A. Leveling)  Expect completion ~6/2005 Prototype 2 Lenses  Delayed due to lead engineer (Pat Hurh) assuming role of Mech. Supp’t department head  Diffusion bonding complete ~mid-March 2005  Ready to fill ~late June 2005  Ready to test ~ late August 2005 (~6 months of testing after that) New Lens Transformer  Rejected vendor’s transformer due to faulty machining  Expect completion by ~5/30/2005