f Project X: Recycler 8.9 GeV/c Extraction D. Johnson, E. Prebys, M. Martens, J. Johnstone Fermilab Accelerator Advisory Committee August 8, 2007 D. Johnson

f Outline  Accelerator Layout  Beam Parameters  Extraction Options  Conclusions Aug 8, 2007 AAC meeting D. Johnson 1

f Cartoon of MI/Recycler Extraction (and Injection) MI30 MI10 MI52 MI40 MI60 Recycler Main Injector 8-GeVline Nova: Booster-Recycler Nova: Recycler-MI P1 line Proposed: Recycler-P1 MI abort Recycler abort Abort Bypass NuMI MI62 MI22 MI32 Project X - Linac existing planned Potential To be removed R R R Aug 8, 2007 AAC meeting D. Johnson 2

f Extraction location – 52  Main Injector  MI extracts to Tevatron, Pbar, and Switchyard via P1 beamline  Extraction channel: kicker/electrostatic septa at Q520 and magnetic Lambertson Q522  Recycler  Add kicker and/or septa at 520 with Lambertson at 522 bending down toward the P1 line.  Connect with P1 line upstream of Q703 [Ref. Beam doc 2678] septa kicker Lambertson’s Aug 8, 2007 AAC meeting D. Johnson 3

f Extraction location -40  Both MI and Recycler abort extraction system located at 40  Share same abort absorber  Beam bypass built into beam absorber  EPP (1994) developed “green field” experimental area downstream of MI-40  Addition of kicker/dipole in beam line to switch between abort and experimental area  Beam could be supplied to area from either MI or Recycler  No effort has gone into further development since 1994 Aug 8, 2007 AAC meeting D. Johnson 4

f Extraction from the Recycler  Machine/Beam parameters  Linac operates 5 Hz, 9 mA, and 1ms injection time Corresponds to about 5.3E13 protons injected into Recycler with a 700 ns abort gap each Linac cycle  3 cycles for MI injection w/ cycle of 1.4 sec 160 kW (8GeV)  4 cycles for use (elsewhere) > 200 kW (8GeV)  Bunch filling determined by digital 325 Mhz chopper in Linac  Inject into 53 Mhz buckets using transverse and longitudinal painting to 25  -mm-mr and 0.5 eV-sec  Required dp/p of 0.5% with chromaticities of -10 to full intensity  Harmonic number, h = 588 (84x7)  Circumference meters  Tunes and (design)  Max number of bunches: ~546 (42 buckets abort gap)  RF HV 800 kV 1 st and 400 kV 2 nd harmonic  Bunch length ns Aug 8, 2007 AAC meeting D. Johnson 5

f Fast Extraction  Utilize combination of kicker (H) and magnetic Lambertson (V) separated by 90 o in phase  Extract full turn  Requires an abort gap in beam (750ns) – currently done in MI  Rise time of 750 ns, flattop time 9.8  s  Extract 1/6 th of full ring (one Booster batch)  Requires kickers with 60 ns rise/fall time  Similar to current MI injection kicker (vertical)  Horizontal kicker being developed for Nova injection  Operation at 15 Hz implies 3 “batches” extracted/Linac cycle  Bunch-by-bunch extraction  Requires 6-8 ns rise/fall time with 10-12ns flattop  Requires combination of fast kicker and electrostatic septum  For pulsar voltage of 20 kV on each +/-plate requires only about 5m of kicker 25 mm separation at electrostatic septa  Power supplies have been developed which have similar parameters (LLNL) – not unthinkable at 8 GeV Aug 8, 2007 AAC meeting D. Johnson 6

f Resonant Extraction  Previous experience:  Fermilab Main Ring and Tevatron ½ Integer Resonant Extraction (400 GeV and 800 GeV program)  Fermilab MI ½ Integer Resonant Extraction (120 GeV)  Fermilab has never utilized 1/3 Integer Extraction  1/3 Integer resonant extraction utilized by other labs, ANL, BNL, CERN  1/3 rd Integer resonant extraction from the Debuncher is being investigated (mu2e collaboration meeting, Aug 1, 2007)  Fermilab has never implemented resonant extraction at 8 GeV  Simulations, utilized for MI resonant extraction at 120 GeV,[Beams-doc-092] have been adapted for 8 GeV MI resonant extraction [J. Johnstone] 1000 particles (all particles accumulated in extracted phase space) 3 cases with all particles at dp/p values of -.15%, 0%, or +.15% Circulating beam is a snapshot halfway thru extraction Septum located at -16mm and base tune set to from the half- integer  Large circulating beam size /aperture ratio problematic  Large tune spread due to momentum spread/chromaticity problematic Aug 8, 2007 AAC meeting D. Johnson 7

f Resonant Extraction From the Recycler  Option NOT VERY ATTRACTIVE, if even possible MI 120 GeV resonant extraction septum Lambertson dp/p < 0 dp/p > 0 MI (Recycler) 8 GeV extraction septum For Comparison dp/p = % 0 % %  x = -10 units  = +/  = Initial conditions used in simulations:  = 25  -mm-mr Low dp/p extracted beam overlaps high momentum circulating beam: No GAP dp/p = 0 Lambertson Aug 8, 2007 AAC meeting D. Johnson 8 Onset of extraction

f Conclusions  Two extraction channels from the Recycler have potential for being developed  52 could supply beam to all existing areas  40 is a new “green field” area that could be developed  Fast extraction of beam from single bunches to a full ring appear to be feasible (R&D needed for bunch- by-bunch)  Resonant Extraction from the Recycler does not appear to be feasible Aug 8, 2007 AAC meeting D. Johnson 9