1. f Antiproton Source Apertures Steve Werkema DOE Tevatron Operations Review March 22, 2006

2. f DOE Tevatron Operations Review – Steve Werkema 2 Outline 1.Overview of Activities since March 2005 a.AP2 line b.Debuncher c.D-A line d.Accumulator 2.Work remaining for each of the above 3.Conclusions Note that a Goal admittance of 35  mm-mrad means accepting a beam emittance of 330  mm-mrad

3. f AP2 Line Accomplishments and Work Remaining

4. f DOE Tevatron Operations Review – Steve Werkema 4 AP2 Beamline AP2 Accomplishments:  BPM DAQ Upgrade (completed in June 2005)  Orbit control  Lattice measurements  Observation & correction of short and long term beam motion trends  Four new dipole correctors have been installed  Implemented automatic orbit correction during stacking  Much of the line has been steered to quad centers  Conducted an obstruction search with a borescope  No obstructions found

5. f DOE Tevatron Operations Review – Steve Werkema 5 AP2 BPM Upgrade  BPM DAQ upgrade installation completed in June 2005  Debuncher injection kicker noise problem solved by installing inline high pass filters and amplification of the signal at the source.  These amplifiers are being replaced by low noise amplifiers during the present shutdown  BPM output is sent to the control system on every beam pulse. The data is available as ACNET devices – allows easy readout by client software and other users.  AP2 BPM positions and intensities are routinely data logged.  Software providing for the display, storage, and analysis of AP2 BPM data has been written and is in operational use.  RMS fluctuation in the readout of the AP2 BPMs varies from 100 μm to 500 μm (average is 200 μm).  Good enough for orbit correction, but compromises lattice measurements  Should be improved with the installation of low noise pre-amps

6. f DOE Tevatron Operations Review – Steve Werkema 6 AP2 BPM Upgrade AP2 BPM difference orbit during reverse proton studies RMS is shown in green We expect the installation of new low noise preamps will reduce the readout fluctuations to 100 – 200 μm. 5 mm 1 mm

7. f DOE Tevatron Operations Review – Steve Werkema 7 AP2 Beamline – Automatic steering Data log display of four BPMs at the downstream end of the AP2 line from 10/1/05 to 1/16/06. Introduction of automatic steering (a.k.a. Oscillation Overthruster) in the 120 GeV and AP2 lines significantly reduced variations in the AP2 beam trajectory. 10 mm

8. f DOE Tevatron Operations Review – Steve Werkema 8 AP2 Beamline Work Remaining:  Replace AP2 beam stop (i.e. eliminate 2 vacuum windows and 12 feet of spoiled vacuum)  to be  completed this shutdown  Steer upstream end of the beamline (including Li Lens)  Match lattice to the Debuncher

9. f Debuncher Accomplishments and Work Remaining

10. f DOE Tevatron Operations Review – Steve Werkema 10 Debuncher Debuncher Accomplishments:  Completed installation and commissioning of all moveable quad stands. We don’t plan to install any more!  Installed and commissioned a ramped Debuncher EXtraction (DEX) bump.  Lattice modified to decrease  -functions at limiting apertures.  Eliminates the need to widen the aperture of the band 4 stochastic cooling arrays  Substantial beam study time to steer the closed orbit to quad centers and work on the aperture  Found and removed two aperture restrictions: horizontal and vertical schottkys Net Result:  25% increase in Deb Admittance in past year: A x = 32.6  mm-mrad, A y = 34.6  mm-mrad  32% increase in AP2 + Debuncher admittance: A x = 33.3  mm-mrad, A y = 31.2  mm-mrad

11. f DOE Tevatron Operations Review – Steve Werkema 11 Debuncher – Finding Limiting Apertures Debuncher “Running Wave” application: A pair of trim dipoles are used to generate a closed orbit oscillation that is scanned in phase so that the maxima and minima move over the entire length of the Debuncher. Beam loss monitors are used to resolve the 19-fold ambiguity in the location of the orbit extrema.

12. f DOE Tevatron Operations Review – Steve Werkema 12 Debuncher Work remaining:  Debuncher extraction kicker aperture upgrade  Improves horizontal aperture for |  p/p| > 0  Motorize Debuncher extraction kicker stand  Motorized girder will be installed this shutdown  53 MHz upgrade to Debuncher BPMs  Allows orbit monitoring and correction during stacking  Possible further adjustments to the lattice  Quad shunts are being configured for this during the present shutdown  Correct horizontal orbit in the arcs  We skipped this on the first pass because it will change the energy

13. f D-A Line

14. f DOE Tevatron Operations Review – Steve Werkema 14 D-A Line Accomplishments:  Aligned orbit to quad centers  Implemented injection error correction for proton injection into the Debuncher and  p injection into the Accumulator  Investigated matching to the Accumulator  D-A line appears to be matched to the Accumulator

15. f DOE Tevatron Operations Review – Steve Werkema 15 D-A Line  Limiting apertures are the Accumulator injection septa (~10  mm-mrad)  Beam from Debuncher is cooled transversely to < 3  during each stacking cycle Conclusions: 1.Maximum transfer efficiency achieved with cycle times > 2.0 sec 2.Beam bigger than 2 – 3 π could be scraping upon injection into the Accumulator

16. f Accumulator Accomplishments and Work Remaining

17. f DOE Tevatron Operations Review – Steve Werkema 17 Accumulator Accomplishments: Spent 4½ shifts of beam study time to improve the Accumulator aperture.  Identified an aperture restriction – quadrupole pickup Quad pickup has been removed  Scanned all moveable devices

18. f DOE Tevatron Operations Review – Steve Werkema 18 Accumulator Admittance DateInjectionCentralCore 8/25/1999 HVHV 8.3  9.6  10.0  9.4  8.2  7.7  2/15/2006 Start of studies HVHV 6.3  7.4  2/17/2006 End of studies HVHV 6.3  9.2  7.0  7.9  6.6  Improvement: Horizontal – 11%, Vertical – 7% Apertures remain substantially smaller than they were in 1999.

19. f DOE Tevatron Operations Review – Steve Werkema 19 Accumulator Coupling on extraction and central orbits CoreInjection Horizontal Vertical

20. f DOE Tevatron Operations Review – Steve Werkema 20 Accumulator Work remaining:  Correct central orbit to quad centers and re- center moveable devices  Correct coupling on the injection orbit  Look carefully at acceptance of Accumulator injection channel

21. f DOE Tevatron Operations Review – Steve Werkema 21 Conclusions  The Perfect Storm The confluence of: major Tevatron disasters  copious beam study time + the upgrades installed so far + new instrumentation = a significant (~30%) improvement in the AP2 and Debuncher acceptance. We are now within 10% of our Run II upgrades admittance goals.  Several important tasks remain, indicating a good likelihood of even further improvement:  Lattice improvements in the AP2 line and Debuncher  New AP2 beam stop  Debuncher extraction kicker upgrade  Debuncher BPM 53 MHz upgrade  Accumulator orbit correction  Completion of the Lithium Lens upgrade (summer ‘06)