Overview of Project X ICD and RD&D Plans David Neuffer material from Paul Derwent & Sergei Nagaitsev (AAC Meeting, February 3, 2009)

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Page 8 IDS March, GeV Operating Scenario in ICD 1. Five out of seven linac pulses are unused. (NuMI + mu to e expts.) 2. 8e13 every 1.4 sec to Mu2e may not work – (1) high tune shift in Debuncher, (2) long emittance too high (150 eV-s)→ (use multiple bunches Acc. to 1in Deb.) 3. linac chopping pattern must be modified for mu to e cycle 4. Note: Mu2e beam power in this scenario is 75 kW

Page 9 IDS March, 2009 Project X Requirements (ICD) ICD v1.0 exceeds the design criteria in terms of beam power –v1.0 – October 31, 2008 Previous version of requirements (AAC May 2008): 360 kW (ILC- like) linac parameters –1 MW at 8 GeV was arrived at by requiring that the MI is loaded in a single linac pulse (1.6e14 ppp at 5 Hz)

Page 10 IDS March, 2009 ICD -> RD&D Program The goal of the Project X RD&D program is to provide support for a CD-2/3a approval in Spans 4 FY’s. –Design and technical component development; –Development of all project documentation mandated by DOE 413.3; –Formation of a multi-institutional collaboration capable of executing both the R&D plan and the provisional construction project. The primary technical goal is completion of a Conceptual Design Report, followed by a fully developed baseline cost estimate and schedule, and supported by a technology development program. –Capability of delivering in at least 2 MW of beam power over the range 60 – 120 GeV, simultaneous with at least 150 kW of beam power at 8 GeV.

Page 11 IDS March, 2009 RD&D Technical Goals The plan is documented at: projectx.fnal.gov/RnDplan/index.html Complete conceptual design and cost estimate for Project X: –technical and conventional construction elements, –systems integration, and –installation and commissioning plan. Supporting technology development program targeting key accelerator physics and engineering challenges – incorporating simulations, experiments, and prototype construction as appropriate. Alignment with the SRF/ILC program: –Primary goal is to develop a set of technologies applicable to both ILC and Project X  Common cavity/cryomodule design, rf sources and distribution –Project X linac designed to accommodate accelerating gradients in the range 23.6 – 31.5 MV/m (XFEL – ILC)  Final design gradient determined prior to CD-2.

Page 12 IDS March, 2009 Design Criteria Derived from 3 missions of Project X Neutrino program with MI: 2 MW at GeV Deliver 1.6e14 protons every 0.8 sec (with specific beam requirements); Mu2e experiment at 8 GeV: 150 kW slow extraction Specific beam requirement Deliver 1.4e13 protons per spill cycle (15-20 Hz) Provide a plausible self-consistent path to a 2-MW (and higher) proton source for a muon collider single bunch, 2-ns rms, 15 Hz, 2mm rms spot size on target, 8-20 GeV We have concluded that the total Project X beam power of 0.5MW at 8 GeV is sufficient to meet first 2 criteria Baseline missions

Page 13 IDS March, 2009 Operations scenario (64 GeV MI)

Page 14 IDS March, 2009 Mu2e beam requirements Slow extraction from the Debuncher: –8 GeV, 150-ns (FW) bunch length, 20 eV-s (95%) max. long. emittance –tune shift limit for slow extraction ≤0.05; 1.4e13 per bunch max. Recycler can be filled with 7 barrier-bucket bunches (1.2-µs long), long. emitt. 10 eV-s, 0.1-µs gaps, Requires a different chopping pattern Bunches are then transferred to the Accumulator (at ~15 Hz rate) stacked in Accumulator, for bunch rotation (10 ms) and then to the Debuncher 1 µs 7 bunches

Page 15 IDS March, 2009 Injection scenario for mu2e Bunches from linac: –±12MeV; ±2mm –Drift to ±12mm Debuncher Line rf reduces ΔE –ΔE < ±2MeV Inject within h=7 barrier buckets – Obtain Accumulator length batches –ε L = 4MeV x 9μs = 36 eV-s Low-voltage rf prebunches beam for transfer to recycler 6 batches (1 for abort gap) Recycler Accumulator = 1/7 of Recycler

Page 16 IDS March, 2009 Injection scenario for mu2e (2) Rebunch at 53MHz (Recycler) –Weak rf Transfer 1batch at time into accumulator Momentum stack 6 batches from Recycler into Accumulator in ~0.1s) –Similar to Booster scenario –ε L = ~36eV-s Bunch in Accumulator h=8?, transfer single bunches to Debuncher Slow extract from Debuncher –~0.12s/Debuncher cycle Intensity (1 linac pulse/1.4s) : 1x10 14 p/1.4s x 2x10 7 s/yr = 2x10 21 protons/yr =(1.4 Zp/year)

Page 17 IDS March, 2009 Beam Formation for mu2e expt. Sample scenario –bunch at harmonic 4 in accumulator –transfer bunch by bunch to Debuncher for mu2e slow extraction –scenario for Booster era mu2e Higher Harmonic –for higher-intensity Project X –h=8 ?

Page 18 IDS March, 2009 Alternative configurations Alternative configuration studies are mandated by the DOE project Critical Decision process. ACD and its cost range estimate is being created in parallel/series to the ICD by the same people. Work on the ACD is part of the RD&D plan ACD is considered: –in support of baseline design criteria (neutrino and mu2e missions);  Examples: 1-ms pulse vs. 3-ms, TSR vs. L-band elliptical cavities –in support of future upgrades;  Path to 2  4 MW –in support of project scope changes;  not covered in this talk

Page 19 IDS March, 2009 Why ACD for baseline missions? The Recycler is far from being ideal for the proton accumulation: –fixed energy, permanent magnets; –small acceptance; –Large transverse impedance because of wall resistivity; –very long (3.3 km) for an 8 GeV ring; –no solution found for slow extraction; Space-charge tune shift is an issue –The maximum tune shift is limited by how much beam losses one can tolerate –Fermilab Booster has a tune shift of -0.3 at injection (400 MeV); it looses 10-15% of particles at injection or 300 W (at 7.5 Hz operation) –Fermilab MI presently has a tune shift of at injection (w/ slip stacking); it looses 5% of particles (mostly because of slip stacking) at injection or 1.5 kW. Number of protons per bunch: 10e10

Page 20 IDS March, 2009 Tune shift 2 MW operation in the MI requires 1.6e14 protons at injection in the Recycler and MI or 3e10 ppb  3 times what we have now. If do nothing -- beam losses will be too high. Our solution in the ICD – painting (transverse and longitudinal): –Make transverse distribution uniform (by “painting”) –Make transv. emittance bigger: 15 to 25 µm (100%) –Make bunches longer (long. emittance increase, two-harmonic rf) Ultimately, no more beam power upgrades for MI unless the injection energy is increased.

Page 21 IDS March, 2009 Are based on the idea that one can reduce the linac energy by making a smaller-size ring with bigger acceptance A good alternative appears to be an 800-m Rapidly Cycling Synchrotron (1/4 of MI) with a 2-GeV injection Alternative configurations Pulsed H - Linac Stripping Foil Synchrotron

Page 22 IDS March, 2009 Cartoon for scale 21 GeV RCS 2GeV Linac 4GeV Linac

Page 23 IDS March, 2009 Upgrade path Provide a plausible self-consistent path to a 2-MW (and higher to 4 MW) proton source for a muon collider Project X -> –Neutrino factory -> Muon collider We have to anticipate a coherent upgrade path –Energy choice –Initial infrastructure choice –Future developments The most general structure for Muon collider proton source –Linac -> Synchrotron (?) -> Accumulator ring (?) -> Compressor ring –single bunch, 2-ns rms, 15 Hz (or higher), 5-20 GeV, 2mm rms spot size on target

Page 24 IDS March, 2009 Alternatives to be considered 1 2 3

Page 25 IDS March, 2009 ICD and ACD Meets design criteria for nu and mu2e

Page 26 IDS March, 2009 Conclusions for upgrades study (S. Nagaitsev) Option 1 does not work Option 2 has a limited beam power reach: 1 MW for 8 GeV, 15 Hz, single bunch (2-ns rms, 2-mm rms size) – (4MW for 4 bunches?) Option 3 has a power reach to 4 MW at 21 GeV, allows to increase the beam power in the MI beyond 2 MW by increasing injection energy to 21 GeV.

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Page 28 IDS March, M$ 189 M$ labor 555 M$ M&S March 17 Cost Review

Page 29 IDS March, 2009 Summary Cost Review should establish project scope so that DOE can issue CD0 for project X “Mission Need” “Upgradeable to neutrino factory / μ + μ - Collider”

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Page 31 IDS March, 2009 Project X scope 120 GeV fast extraction spill 1.6 x protons/1.4 sec 2 MW 8 GeV H - Linac up to 1.6x10 14 x 5 Hz Flex chopper pattern To Accumulator 8 GeV extraction (fast) 150 kW total Stripping Foil Recycler 1 linac pulse/fill Main Injector 1.4 sec cycle Single turn 8 GeV GeV HE Linac 0.42 GeV LE Linac

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