Optics, Apertures, and Operations

1. Nova-doc 4930 Optics, Apertures, and Operations Dave Johnson July 12, 2010 NOvA/ANU Recycler Upgrades Review

2. Opening Statements • d • Optics • Injection & Extraction transport lines can be described as FODO lattices with beta functions very similar to the Recycler and MI (i.e. maximum betas ~60 m or less) and vertical achromats. • Apertures • d • Operation • d

3. HKICK VLAM (MLA) V2 (PDD) 102 100 103 104 Recycler PDDM K QR852 QR853 847 HBEND (35 mr) 848 850 849 852 851 MI8 MI 101 103 102 8 Gev line 102 V1 (switch) H Vup lamb Vdn Inj kicker Recycler Injection • Continuation of 8 GeV line FODO lattice using permanent magnet dipoles and quads with the addition of a vertical achromatic dogleg • Usual complement of BPM’s, Loss monitors, multiwires, and correction elements • Powered trim quads (MQT) are • included for matching. Only two power supplies required: Vertical switch magnet (ADCW) Injection Lambertson (MLAW)

4. Recycler Extraction • Vertical achromat between RR and MI (FODO lattice similar to MI) • Design similar to existing R22 and R32 transport lines • Permanent magnet quads (with electromagnet trims, MQT) • Usual complement of BPM’s, Loss monitors, multiwires, and correction elements • Powered trim quads (MQT) are • included for matching. • Only 3 power supplies required: • Extraction Lambertson (MLAW) • Vertical Dipoles (ADCW) • Injection Lambertson(ILA)

5. 400 402 Dump LAM402 LAM402 KICKER MI EnclosureWall Recycler Abort Line (existing) • Recycler abort line shares the beam absorber with the MI. • Contains vacuum break downstream of the Lambertson (do we keep ?) • Abort kicker double duty as pbar extraction kicker (pbar function will go away with Nova) • NEW > Install gap clearing kickers so the beam in the injection gap is cleanly sent to the absorber Oct 2000 Recycler e-log RR 5 MI • Assume ~5E13/1.33 sec • Assume 2% in gap • 1E12/1.3sec • 1 kW

6. Apertures • Expect NOvA Booster batch intensity at approximately the same as today ~4E12/batch • Current measured transverse emittance of beam from Booster (during slip stacking operation) is roughly 12-14 p-mm-mr. • 6s values of 21.6mm to 23mm and 10s values of 36mm to 38.4mm (for beta=60m) • Minimum injection line physical apertures based upon a 10s beam envelope for a 25 p-mm-mr emittance (s=5.14mm @b=60m) • Minimum extraction line physical apertures based upon a 10s beam envelope for a 20 p-mm-mr emittance (s=4.6mm@b=60m) • Utilize same style of beam pipe that exists in the MI, RR, and 8 GeV. • The ADC dipoles and the MLA Lambertsons are having new versions built with wider apertures. • The main aperture constraints are at the injection extraction points (partially mitigated by creating a larger aperture Lambertson) • Beam pipe choice considered installed magnet pole tip dimensions and design lattice functions (expected beam size). Details in following talks!

7. Apertures (2) • A partial list of magnet and beam pipe apertures Use at horizontal quad locations Use at vertical quad locations

8. Min horizontal aperture Vertical aperture Apertures Recycler Injection Provide for loss free transmission Expect emittance of 12-14 p (history shows with large tails)-> clean up with MI8 collimation Would like to provide at least 1 s for loss free steering Assume 99% in 6s -> use 10s with 25p beam

9. Apertures Recycler Extraction • Maximum beta ~60m at quad locations (10s of 25p = 51.4mm) • Vertical locations utilize 3” beam pipe (73mm) while horizontal locations use RR beam pipe (95mm) Recycler Extraction Lambertson Main Injector Injection Lambertson

10. 24” round 4” round H ellipse V ellipse L H V V V 24” round 4” round H ellipse V ellipse Apertures Recycler Abort • Abort line apertures OK for 10s of 14p 10s of 14p 10s of 25p 6s of 25p Horizontal aperture (red), vertical aperture (blue) Need to perform aperture scan of abort line… schedule during start up

11. Operation • Booster is assumed to be operational at 15 Hz • Expected operational scenario • Injection takes place during MI ramping (implications due to stray field on injection line) • We expect all injections into Recycler will occur without interruption, but we will have the capability of interleaving injections at a 15 Hz level • Gap clearing kicker at RR40 to clear any beam in injection gap before each injection • Beam extracted without capture in 53Mhz (MI is at 8 GeV) • Tuning • Instrumentation • 4 MW in beam lines • 4 MW in Recycler • BPM’s • Loss monitors (extra loss monitors around Lambertsons and switch magent • Steering • Define position and angle mults at Lambertson (approximately 2mm/amp on corrector for injection line) • Define Recycler closed orbit bumps (both injection and extraction Lambertsons) • Define MI closed orbit bumps around Lambertson • Modify closure program to Recycler and MI injection • Matching • The permanent magnet gradients for both transport lines set to match into Recycler/MI with the trim quads set to zero • Permanent magnet strength ~25 kG/m (2 or 3 at each location) 50 to 75 kG/m • Trim quads (MQT) 0.9 kG/m/Amp with 2 at each location 1.8 kG/m which gives a 24 to 36% quad strength tuning range for 10 Amps • Recycler lattice functions (b,a) may be adjusted +/-25% with less than 6 amps on any trim quad • Use profile matching for Recycler injection (MW) and TBT sigma matching for MI injection (IPM) with profile matching in both transport lines.

12. Summary • The transfer line optics design were based upon existing transfer lines such as the 8 GeV line and RR22/32 (i.e we have experience designing and building permanent magnet lines and rings) • The transfer line optics have been firm for well over two years. • Beam line designers have worked closely with the Mechanical Support Department (Linda and Bill) to optimize locations of elements and specify appropriate beam pipe apertures. • Plan to document existing Recycler abort aperture • Power supply regulation requirements and tuning scenarios have been addressed