# Presentation: 506425

## Proton Plan 

- Eric Prebys FNAL Accelerator Division

## Disclaimers

- The “Proton Plan” extends through the end of the collider program (2009 or 2010)
- Provides for 1-2e20 protons per year to the 8 GeV (BNB) line.
- The (proposed) NOvA/ANU upgrades would send ~all of these protons to the Main Injector for NuMI
- We have some confidence we can maintain an 8 GeV capability at the ~few 1020 p/yr in this era, BUT
- There is as yet no lab mandate to support an 8 GeV program in the post-collider era
- Projections and estimates have not been vetted in any way
- There might be competing users for 8 GeV protons

## The Fermilab Accelerator Complex

- MinBooNE

- NUMI

- =Proton Plan System

- =Proton Plan Customer

## Preac(cellerator) and Linac

**“****Preac” - **Static Cockroft-Walton generator accelerates H- ions from 0 to 750 KeV.

**“****Old linac”(LEL)-** accelerate H- ions from 750 keV to 116 MeV

**“****New linac” (HEL)-** Accelerate H- ions from 116 MeV to 400 MeV

## Booster

-  Accelerates the 400 MeV beam from the Linac to 8 GeV
- Operates in a 15 Hz offset resonant circuit
- Sets fundamental clock of accelerator complex
- From the Booster, beam can be directed to
-  The Main Injector
-  MiniBooNE (switch occurs in the MI-8 transfer line)
-  A dump.
- More or less original equipment

## Main Injector

-  The Main Injector can accept 8 GeV protons OR antiprotons from
-  Booster
-  The anti-proton accumulator
-  The Recycler (which shares the same tunnel and stores antiprotons)
-  It can accelerate protons to 120 GeV (in a minimum of 1.4 s) and deliver them to
-  The antiproton production target.
-  The fixed target area.
-  The NUMI beamline.
-  It can accelerate protons OR antiprotons to 150 GeV and inject them into the Tevatron.

## Limits to Proton Intensity

- Total proton rate from Proton Source (Linac+Booster):
- Booster batch size
- ~4-5E12 protons/batch, depending on beam quality required.
- Booster repetition rate
- 15 Hz instantaneous
- Currently ~9Hz, limited by RF system.
- Beam loss
- Damage and/or activation of Booster components
- Above ground radiation
- Total protons accelerated in Main Injector:
- Maximum main injector load
- Six “slots” for booster batches (3E13)
- Up to ~11 with slip stacking (4.5-5.5E13)
- Beam stability (RF issues)
- Beam loss concerns
- Cycle time:
- 1.4s + loading time (1/15s per booster batch)

- Historically our biggest worry

- Critical path for NuMI/MINOS

## Some Handy Rules of Thumb

- 1 Booster Hz @ 5E12 protons
- ~1E20 protons/year
- ~6KW at 8 GeV
- ~100 kW at 120 GeV
- Considerations
- <5E12 for slip stacked batches or low losses
- Realistic up times and intensity ramp - ups

## Review: Main Injector Loading

- The Main Injector has six usable “slots”, into which Booster batches may be placed.

- More batches may be loaded, using “slip stacking”, in which an initial batch in the Main Injector is accelerated such that a subsequent batch will be at a slightly different energy.
- The two will then drift together and can be captured as a single batch (with at least twice the longitudinal emittance).
- This will be done in the Rycler in the NOvA/ANU era

## NuMI Operating Modes

- Initial NuMI operation (“2+5”):
- Two batches slip stacked for antiproton production.
- Five more batches loaded for NuMI
- All will be accelerated together.
- This is the current standard operation.
- Ultimate NuMI operation (“2+9”):
- Five batches will be loaded into the Main Injector, leaving one empty slot.
- Six more batches will be loaded and slipped with the first to make two for antiproton production and 9 for NuMI.
- This will begin after 2007 shutdown
- NOvA Operation (2010 +?)
- Slip stacking will be done in Recycler to eliminate loading time

## Time Line

- “2+5”

- “2+9”

- This time will be eliminated by preloading in Recycler after collider program (ANU)

## Staged Neutrino Program: What’s in a Name?

- Current Proton Plan
- A combination of Main Injector RF improvements and operational loading initiatives will increase the NuMI intensity to 4-5E13 protons to NuMI per 2.2 second cycle (~3E20 p/yr).
- Ultimately 320 kW to NuMI (400 kW w/o pBar)
- Runs through end of collider program
- ANU (“Accelerator NuMI Upgrades”, combined with NoVA as per DOE directive)
- Retask Recycler as a preloader to save proton loading time to the Main Injector
- ~700 kW to NoVA
- Presently being formalized and baselined
- Up to 35 kW (~5E20/yr) of excess 8 GeV protons, IF the Booster runs at 15 Hz
- SNuMI (formerly “SNuMI II”)
- Use pBar accumulator to momentum stack protons prior to boxcar stacking in the Recycler
- Ultimately ~1.2 MW to NuMI
- NO excess 8 GeV capacity
- “Project X” (formerly “Proton Driver”, “HINS”, “Foster’s Folly”...)
- New 8 GeV proton Linac to Main Injector
- Exploit synergy with ILC
- Lots of enthusiasm for this project!!!
- ~2 MW to NuMI
- Up to 200 kW (3E21/yr) of excess 8 GeV beam, but might be complicated to get it to BNB line (from Recycler)

- Only official part

## Proton Plan Charge

- Develop a plan for a reasonable set of improvements and operational initiatives to  maximize proton delivery to NuMI and the Booster Neutrino Beam (BNB) over the next ten years or so.
- Estimate the budget and timeline for these improvements.
- Estimate proton delivery to both beam lines if the Plan proceeds on schedule.

- Very important

## Summary: Significant Elements of Plan

- Linac
- Stockpile two year supply of spare 200 MHz power amplifier tubes (7835’s), in the event of an interruption in supply
- Characterize and improve Low Energy Linac Low Level RF
- Booster:
- Replace and reconfigure injection bump (ORBUMP) system.
- Relocate 8 GeV dump from Booster tunnel to MI-8 transfer line
- Make Booster robust to 9 Hz, and understand requirements to go to 15 Hz
- Design, build, and install new corrector system
- Install half of longs in 2007 shutdown
- Rest of longs in 2008
- Shorts ??
- Main Injector:
- Replace seven quadrupoles with increased aperture versions, to reduce injection and extraction losses.
- Operationally develop multi-batch and multi-batch slip stacked operation
- Design and install collimation system, both in the MI-8 line and in the MI ring
- Modify injection kicker to allow multi-batch slip stacked operation
- Characterize and improve to RF system, to support high intensity operation.

- Red = complete, Green = complete in this shutdown, Blue = to do

## Proton Delivery

- MiniBooNE

- NuMI

- Average  Booster Activation

- Factor of 15 increase in protons

## Total Booster Output

## After the 2007 Shutdown

- After the 2007 shutdown, the remaining Proton Plan Projects will he
- Rest of Booster Correctors
- In the 12 remaining long sections.
- In the 24 short straight sections.
- Upgraded gamma-t jump system in Booster *(maybe)*
- Capable of running at required repetition rate
- Must be installed along with correctors
- Booster chopper notcher
- Reduce losses when creating extraction loss
- These are all currently scheduled for the 2008 shutdown
- We allow a year after this to achieve the ultimate benefits
- Proton plan will officially end in mid to late 2009
- It is likely that the plan will absorb some scope to enable full 15 Hz operation.
- Refurbish RF anode supply
- Retrofit half the RF bias supplies
- Recommission RF cavity tuner cooling
- Not necessary for NuMI

## Booster Corrector System

- Biggest single project in plan
- Replace all 48 (original) Booster corrector packages.
- Unique new design
- Six independent multipoles
- Stronger H and V dipoles
- ±1cm beam motion throughout cycle
- Stronger quad
- Arbitrary tune working point throughout cycle
- Skew quad
- Coupling, same strength as before.
- Sextupole and skew sextupole at every period.
- Less emittance blowup
- More control of harmonic resonances.
- Integrated BPM
- Saves space

- ~16”

## Corrector Prototype

- Bad hair day

- Ready for testing

## Potting

## Prototype Installation

- All power supplies and water connected
- Pulsing (hard) on beam off cycles
- Proceeding with beam tests

## Proton Plan Projections

- Proton Plan represents the first ever attempt to accurately predict total proton output from Booster.
- Determining Booster output capacity is challenging.  Our procedure is to:
- Evaluate the potential of particular improvements based on effective aperture increase or uncontrolled beam loss reduction:
- For example, if something reduces uncontrolled loss by 10%, it has the potential to allow us to send 10% more beam.
- Consider the following scenarios:
- “Design”: After *one year* of tuning, we realize *half* of the potential benefit.
- “Fallback”: After *one year* of tuning, we realize *one quarter* of the potential benefit.

## Factors Considered in Projections

- Linear ramp-up to see benefit of improvements
- Slip stacking efficiency
- Different Booster efficiency for cogged (pBar+NuMI) cycles and uncogged (BNB) cycles.
- Added in for 2006 review
- Annual shutdowns (assume 2 mo/yr)
- Overall asymptotic ramp-up after shutdown (improved for FY06)
- Uptimes: based on MiniBooNE 2004 and NuMI 2005
- Modified for 2006
- Peak to average corrections
- Accounts for non-optimal running

## NuMI Long Term Projections

- 3.2E20 p/yr

- 2.2E20 p/yr

## BNB Long Term Projections

- 1.8E20 p/yr

- 0.7E20 p/yr

## After Collider Program Ends

- Protons now going to pBar production will go to NuMI
- NuMI line goes from 320-400 kW
- Won’t affect 8 GeV program
- 8 Month shutdown for NOvA upgrades
- Currently scheduled for Oct. 1, 2010
- NuMI line will still be limited to 400 kW
- At least 2E20 p/yr of excess 8 GeV protons after this era
- 3 month shutdown for NuMI upgrades
- Scheduled for April 1st, 2012
- 8 GeV line should continue to run during this period with intense protons
- After upgrades, NuMI will take 700kW of protons
- 8 GeV availability depends on excess booster capacity
- Increased repetition rate
- Reduced losses

## Booster Repetition Rate

- The magnetic lattice elements in the Booster operate in a 15 Hz resonant circuit.
- Pulsed magnetic elements and RF system only operate when beam is present (plus conditioning pre-pulses)
- Over the last few years all *magnetic* elements have been upgraded to enable 15 Hz operation
- As Booster losses are reduced, Proton Plan assumes we will go from being loss limited to limited by the 9Hz limit of the RF system
- Half of the RF modulators
- RF tuning cones
- Anode supply tranformers
- NOvA will require 10.5Hz averate repetition rate
- Requires tests
- If modifications are needed, go to full 15 Hz capability
- One way or another, plan to go to 15 Hz capability by NOvA era
- Cost scale ~few $100K
- Presently considered and “operational upgrade”
- Not part of Proton Plan or ANU

## Booster Losses

- We have demonstrated a total Booster output consistent with the needs of the Proton Plan (NuMI + 8 GeV) or NOvA (w/o 8 GeV)
- This *without *the new corrector system or improved “notcher”
- i.e. if we can’t improve on this, the corrector system is a waste of money.
- Calculations indicate that the closed orbit control provided by the new corrector system, together with the reduced losses of a new “notcher”, will allow us to eventually run the Booster at a full 15 Hz with acceptable losses.
- If fully successful, this would provide ~5E20 p/yr to an 8 GeV program

## Summary and Conclusions

- The Proton Plan has done a good job providing and estimating delivery of protons over the last few years.
- We have demonstrated the proton capacity for the rest of the decade, and for the NOvA program (alone)
- If we take the steps to increase Booster rep. rate, and the corrector project is effective at all, we should have some excess Booster capacity even in the NOvA era
- At the level of a few 1020