extraction from the delivery ring november 19, 2013 j. morgan
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Extraction from the Delivery RingNovember 19, 2013
J. Morgan
Muon g-2
AP30
AP50
AP10
M1
Protonremoval
M3
Delivery Ring
AP0
M5
M2
M4
Conceptual Design
Antiprotonproduction
Muon Campus(g-2 operation)
Repurposing Pbar
2
Muon g-2
AP30
AP50
AP10
M1
Protonremoval
M3
Delivery Ring
AP0
M5
M2
M4
Beamline Design – Dual modes
• 3.1 GeV/c Pion decay channel, beta functions need to be as small as possible to maximize muon capture
• 40 pi-mm-mr transverse acceptance, +/- 2% dp/p momentum acceptance
• Beam does a few turns in Delivery Ring to separate and eliminate protons
• Single turn extraction into M4 and M5• 8.89 GeV/c proton beam bypasses
Target Station and is transported in M3• Beam intensity is much higher that
Pbar was or g-2 will be• Protons are resonantly extracted from
the Delivery Ring• Extracted beam is transported down
M4 to the Mu2e Target
g-2 versus Mu2e operation
g-2 operation Mu2e operation
3
Strategy for extraction plan- to provide maximum flexibility between experiments at least expense -
•Work around Mu2e extraction devices• Both single turn (g-2) and resonant (Mu2e) extraction • Resonant extraction more difficult to design for• Electrostatic septa on either side of D2Q3 during Mu2e operation• Lambertsons or Lambertson/bending magnet required on either side of D2Q5• Placement of extraction channel defined by resonantly extracted beam
•Try to reuse existing equipment• Pbar kickers have best combination of strength and aperture at FNAL• Kickers have the smallest physical apertures in the Delivery Ring• Need 8Qx at D2Q5, our donated ANL 8Q32’s need significant work• 8Q32 needs more rad. Hardened water lines, relocated power flags
•g-2 has acceptance goal of 40-pi-mm• Large displacement in both planes through D2Q5 limits aperture• Kickers must produce large separation (~48 mm) in Lambertson• Kicker(s) must produce 7 mr kick to achieve 48 mm separation
• New devices should be based on existing designs• Lambertson is similar to MLAW
• C-Magnet is shorter, larger aperture version of Main Injector ICA and has more turns• Try not to overlap injection and extraction regions
4
Muon g-2
Conceptual Design
Extraction region
8Qx
circulating beam
upstream
downstream
8Q32 40 pi-mm-mr beam envelopes
Mu2e septa, relocated kicker
Delivery Ring extraction
•Extraction layout is driven by requirements for Mu2e resonantly extracted beam• Lambertson is required for Mu2e to work with electrostatic septa
• A larger aperture quadrupole is required at D2Q5, using ANL 8Q32• Mu2e resonantly extracted beam will be much smaller than g-2 muon beam• g-2 and Mu2e will use a Delivery Ring lattice similar to the Pbar Debuncher lattice• Different horizontal trajectories are needed for g-2 and Mu2e
• A large horizontal bump across the extraction region is used for g-2•g-2 needs an extraction kicker for beam to enter the M4 line
• Best location for kickers is where Mu2e septa will eventually reside• A two kicker system will be used for g-2 operation
• Can’t get 40 pi-mm-mr acceptance with 3 kicker system• Existing Pbar extraction kicker magnets can be reused
• Extraction scheme provides 40 pi-mm-mr acceptance for g-2 and a common extraction channel for both experiments
Pbar/Muon extraction Kicker
5
g-2 operation and Mu2e commissioning
Horizontal bend (5)Injection kickers
Injection Pulsed Septumand C-magnet (septum)
Extraction Lambertsonand C-magnet (septum)
Extraction kickers
Vertical bends
Vertical bend
6
Dual running mode configuration
Horizontal bend (5)Injection kickers
Extraction septa (Mu2e)
Extraction kicker (g-2)
Vertical bends
Vertical bend
Injection Pulsed Septumand C-magnet (septum)
Extraction Lambertsonand C-magnet (septum)
7
Muon g-2
Conceptual Design
30 straight section – injection and extraction lines
M3
M4
M5
8
Muon g-2
Mu2e Extraction Trajectory
9
J. Morgan Muon g-2 Independent Design Review June 5-7 2013
Muon g-2
g-2 Extraction Trajectory
10
J. Morgan Muon g-2 Independent Design Review June 5-7 2013
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Identical pair of Lambertsons won’t work, would need offset field region in LAM2
12Lambertson upstream, “C”-Magnet downstream
g-2 Extraction C-Magnet
downstream
upstream
Used 2004 beta functions,Upstream Bx 8.2 m, By 7.7 m (40 pi - 36.2 mm x 35.1 mm)Downstream Bx 14.0 m, By 4.5 m (40 pi - 47.3 mm x 26.8 mm)
40 pi-mm-mr acceptance beam envelopes
minimum separation required
Used 2004 beta functions,Upstream Bx 7.8 m, By 8.2 mDownstream Bx 13.8 m, By 4.1 m
g-2 Extraction Lambertson
downstream
upstream
40 pi-mm-mr acceptance beam envelopes
43.7 mm
13
Candidate large aperture quadrupoles
Pbar LQx (6.5”) magnet Extended aperture along poles
ANL 8Qx (8”)magnetNo extended aperture
14
Changes to improve acceptance in extraction region
•Extraction kicker moved as far downstream as possible• Potential conflict with Mu2e upstream electrostatic septa in dual-mode operation• Kicker must be modified to increase strength (8.33Ω instead of 10Ω) for dual-mode• 48 mm horizontal minimum separation required in Lambertson
•Large horizontal bump across extraction region• Takes advantage of available physical aperture of large quadrupole at D2Q5• Four motorized quadrupoles (existing in Debuncher) used to create bump• Either removed or greatly reduced for Mu2e
•Need 8 inch quadrupole at D2Q5• Pbar LQ magnet can almost work with current configuration• Our only 10Qx magnet isn’t strong enough and is too tall• The ANL 8Q32’s need to be refurbished
• C-magnet used in place of downstream Lambertson• Beams are thread through only one Lambertson instead of two• C-magnet aperture can be centered on extracted beam• Much less stray magnetic field in Delivery Ring• Allows lower trajectory through large quadrupole at D2Q5
15
16
D2Q5 large quadrupole
17Quadrupole can be pitched to improve downstream aperture
•Aperture improves as ELAM and ECMAG move closer to the 8Q32• In general, apertures are driven by g-2 3.1 GeV/c
muon beam, strength by 8.89 GeV/c Mu2e beam• Lambertson has design bend angle of 38 mr, requiring
1.13 T-m of integrated field for the 8.89 GeV/c Mu2e beam
• “C”-Magnet has design bend angle of 57 mr, requiring 1.68 T-m of integrated field for the 8.89 GeV/c Mu2e beam
• Extraction devices under radiation shielding
Cartoon of extraction devices and approximate lengths
18
Extraction magnets
Other magnet work in the near future and a problem
•B2 (GSJ) refurbishment, to replace the P-1 Line V714 C-Magnet• Schedule shows initial planning through December, planning finishing up in January and
work beginning at the end of February• Work scheduled to take 5.5 months
•CDA refurbishment, to replace the AP-1 F-17 C-Magnets• Schedule shows planning in January and February and work beginning at the end of February• Work scheduled to take 5 months
•May have aperture problem with M-5 horizontal bend magnets• Three horizontal bends of 154 mr each, 3.1 GeV/c beam• Original plan calls for MDC magnets which can comfortably provide ~1.6 T-m• Aperture a little tight after carefully considering the beam sagitta• Could “inner” turns of MDC be removed to open up aperture (56 vs. 68 turns)
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