Proton Driver Design Keith Gollwitzer Fermilab February 19, 2014

Proton Driver Outline Overview –History Accomplishments –Current Concept Initial Baseline Selection Schedule Personnel and Effort Technology & Challenges February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Proton Driver at August 2012 MAP Review Overview –Assumed Project X existed –Outlined how to increase Project X beam to 4 MW of 8 GeV H- ions –Accumulation Ring converts ions to protons as well as formats beam into a few intense bunches –Compressor Ring bunch rotates beam to the desired short bunch(s) –Delivery beam line(s) February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Since Last August 2012 MAP Review Project X was split into stages MASS looked at facilities starting with stage 2 of Project X –Proton Driver at 3 GeV Proton Improvement Plan (PIP) II has become the start of a new facility for the Proton Driver MASS assumes that there is a follow-on to PIP II resulting in the equivalent of stage 2 MASS proposes Dual Use Linac –Proton Driver delivers 6.75 GeV proton beam February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Dual Use Linac MAP linac for muon acceleration can be used for H- acceleration –muon beam GeV –H- beam GeV –FNAL SRF expertise is 325 MHz, 650 MHz and 1300MHz MAP has moved to adopt these frequencies February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014) 1-3 GeV GeV GeV GeV

Key Proton Driver Accomplishments Since the August 2012 MAP Review DateDescription FY13 Q2Provided appendix to Project X design report ("Project X Accelerator Reference Design, Physics Opportunities, Broader Impacts") describing upgrade path to MAP Proton Driver FY13 Q3Completed contribution to Proton Driver section and FNAL Project X appendix to IDS-NF RDR FY13 Q4Provided feedback to MASS on 3 GeV Proton Driver option FY14 Q1Interfaced with MASS on 6.75 Proton Driver option based on Dual Use Linac FY14 Q1Accepted initial concept specification described in IPAC12 paper “Design of Accumulator and Compressor Rings for the Project X Based Proton Driver.” (Design concept will be adjusted for operation at 6.75 GeV as well as 8 GeV) FY14 Q2Developed a work plan for executing the IBS process February 19, 2014 Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)6

Present Day Assumptions PIP II: Ion source (5mA) & RFQ (162.5 MHz) provides 1.92 x 10 8 particles per linac bunch. Follow on to PIP II: an additional non-MAP linac supporting high power beam to 3 GeV. –Similar to Stage 2 of Project X 1 MW scenario: Dual Use Linac accelerating ions at 15 Hz to 6.75 GeV –4 ms pulses where 50% beam is chopped in front end so that linac bunches are synched with Accumulator Ring RF February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Previous work had been for 8 GeV Revisit of Rings’ Designs February 19, Accumulator Compressor Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Revisit of Rings’ Designs Previous work has been for 4 MW at 8 GeV Start by revisiting rings for 1 MW at 6.75 GeV –Follow with larger beam power studies February 19, ParametersAccumulatorCompressor Circumference (m) Momentum Compaction Slippage Factor RF Frequency (MHz)3.87 RF Voltage (kV)10240 Synchrotron Tune2.1 x x Peak Current (A) Final rms Bunch Length (ns) Final rms Energy Spread5.2 x x Threshold Impedance (Ohm) Emittance rms (μm)55 Space Charge Tuneshift h/v0.02/ /0.16 Betatron Tunes h/v7.94/ /8.44 Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Stripping System Conversion of MW (or more) ion beam to protons for accumulation will be studied. –Stripping at 6.75 (or 8) GeV –Leveraging SNS experience: 1 MW at 1 GeV Continue Project X work: 300kW at 8 GeV –Same FNAL personnel involved Ideas –Foil (stationary, multiple, rotating) –Laser stripping February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Delivery Beam Line(s) & Focusing System Based upon IDS-NF design. Focusing system will be interfaced with Target system. Bunch instabilities may require extraction of several bunches from the Compressor Ring to be sent through different beam lines to arrive simultaneously at the target. –Focusing system could require a non-standard magnetic element(s) that focuses multiple beams that have little separation February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Initial Baseline Selection Schedule February 19, 2014 Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)12

Personnel & Effort Required A magnet expert is available for consulting Effort to reach IBS will be 1 FTE x 20 months February 19, PersonnelInstitutionTask Alexahin, YuriFermilabRings, Focus System, Instabilities Ankenbrandt, CharlesMuons IncRings, Focus System, Instabilities, Stripping Gollwitzer, KeithFermilabRings, Focus System, Instabilities, Stripping Johnson, DavidFermilabRings, Focus System, Stripping Kapin, ValeryFermilabRings, Focus System, Instabilities Lebedev, ValeriFermilabRings, Focus System, Instabilities, Stripping Neuffer, DavidFermilabRings, Focus System, Instabilities Popovic, MiloradFermilabRings, Focus System, Instabilities, Stripping Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Conventional Technology Ring and beam line magnets –Dipoles –Quads –Sextupoles –Kickers RF Systems Collimators February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Novel Technologies Stripping System –Greater than 1 GeV ion beam energy –Greater than 1 MW beam power Target Focus System –Focus element(s) within greater than 1 T solenoid magnetic field –Multiple beams with small separation being focused February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Stripping System Challenges Static Foil or Rotating Foil –What beam power can be endured? –Multiple beam passes. Scattering. Laser –Viability for MW beam Unconverted Beam –Capture of non-protons (dump) –Limit activation of tunnel and components February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014) Will extend on-going work for linac beam conversion to protons and injection into the Main Injector

Focus System Challenges Target Solenoid Field –A “fringe” field > 1 T exists 5 m upstream of target Magnetic shielding or canceling magnetic field –Off-axis proton beam path is helical Multiple beams with small crossing angles at target –Previous work showed that the separation of 4 beams 5 m upstream of target to be ~15 cm. February 19, Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Proton Driver Conclusion Design work –Revisit of rings designs almost complete –Delivery beam line to be based upon IDS-NF Technology –Most components are conventional –Stripping system will be leveraged from SNS experience and work done for linac beam injection into the Main Injector –Final Focusing element(s) may require design of a non-conventional magnet February 19, 2014 Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)18

February 19, Extras Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)

Possible Layout February 19, GeV Muon Linac (325MHz) To SURF 1 GeV Proton Linac GeV Proton & GeV Muon Dual Use Linac 1-3 GeV Proton Linac Front End Accumulator & Compressor Rings Initial Cool 6D Cool Final Cool RLA to 63 GeV Target Keith Gollwitzer | DOE Review of MAP (FNAL, February 19-20, 2014)