Doug Michael

1
Upgrade Path Presented in Aug. 2002 PI Report

• Doug Michael
• Mar. 6, 2003

2
Contributors to Report

• Direct Contributors
• Michael (Co-chair, worried guy that wants
  protons)
• Martin (Co-chair, Guy whos been around this
  block)
• Marchionni (hard worker on MI and NuMI issues)
• Prebys (Booster Guy)
• Pruss (MI Guy)
• Lucas (NuMI/beams expert)
• Griffin (Expert on lots-o-stuff A real help.)
• Foster (Expert on lots-o-stuff A real help.)
• Choudhary (Newcomer to MI)
• Fields (Experienced Outsider/MINOS
  Collaborator)
• Notable helpful input
• Mishra, Wolff, Chou, Ng, Wildman, Kasper,
  Steimel, Webber, Capista, MacLachlan, Yang,

3
Central Points/Conclusions

• Significant investment in the accelerator complex
  is essential to meet the proton intensity goals
  for NuMI.
• MINOS expectation 3.6x1020 protons per year (now
  known as the extended goal)
• New NuMI goal for 20052.5x1020 protons per
  year
• Assume that MiniBooNE runs simultaneously with
  MINOS
• Identify a path for a total of 12x1020 protons
  for NuMI in 3 years of full-scale running
• Outline a 5 year investment program from FY
  2003-2007
• Numbers are in 1000s and are without contingency
  which is 70-100
• Smaller cost items should be pursued
  first/highest priority
• Big cost items are stretched over several years
  due to practical issues of funding and
  implementation and dont start construction
  immediately to permit design time.
• Important to get started on design for several
  systems as soon as possible.
• Some small cost items are technically tricky and
  will take time to develop and tune.
• Large cost items need solid designs to proceed
  with the investments which will necessarily take
  a few years
• Essential for the lab to invest in some
  alternative to the nominal two-batch
  slip-stacking planned for p-bar production. Best
  alternative is to invest in fast-stacking schemes
  which will also work for NuMI.
• This appears to be the only way to meet the
  MINOS expectation by 2006. It was the best
  judgement of those involved in our committee that
  the MINOS goals are unlikely to be met at all
  without some form of stacking. A faster stacking
  at least will do no harm for NuMI.
• Both Booster and MI investments are essential and
  must proceed in parallel.

4
The 8 GeV Booster

• 8 GeV Synchrotron with 15 Hz resonant magnet
  ramps.
• Currently accelerates 4.5e12 protons per cycle.
  Limited by proton losses (7e12 injected)
• For NuMI/MiniBooNE, the Booster must
• Increase typical acceleration cycle rate from 2
  Hz capability to 12 Hz (with many possible steps
  on the way)
• Increase protons per cycle from typical 4.5e12 to
  5-6e12.
• Increase protons per year from 3e19 to 1.5e21
  radiation and activation issues.
• Decrease longitudinal emittance from 0.15 eVs to
  0.07-0.1 eVs for MI stacking.

5
Booster Improvements

• Hardware upgrades to permit faster cycle time.
  (Some already planned.)
• New extraction septum magnet Success!
• New extraction power supplies Success!
• Upgraded/revamped RF power? No progress
• New hardware to help stabilize the beam, reduce
  proton losses and yield sufficiently small
  emittance on extracted beam to permit Barrier RF
  stacking in the Main Injector
• Ramped correctors (already planned/installed)
  modest success
• New collimators (already planned) Semi-disaster
• Larger diameter RF cavities Accelerated
  progress!
• Inductive inserts, Dampers, pipe liner No
  progress/work
• Additional acceleration RF harmonic cavities No
  work
• Reduce space-charge at injection time by
  spreading beam out
• Reduce longitudinal emittance at extraction
• Cogging Getting started
• Simulations Substantial new work
• Other tuning (dog leg problem) Progress

6
The Main Injector

• 150 GeV synchrotron run at 120 GeV (or lower) for
  NuMI.
• Circumference 7x Booster Room for 6 Booster
  batches. Antiproton production uses just one
  batch per cycle. The remainder are available for
  other experiments, NuMI being the primary user
  for the forseeable future.
• Minimum cycle time at 120 GeV 1.5 s. Cycle time
  for multi-batch NuMI operation 1.9 s due to
  multiple Booster cycles for filling.
• Nominal design for 2.5e13 protons per cycle. With
  only small modifications can probably handle up
  to 5-6e13. The main issue is how to get them
  there. There may be some stability issues too but
  this remains to be seen.
• To go higher than 6e13 protons per cycle,
  additional RF power will be needed as well as
  additional systems to maintain stability.

Recycler Ring
Main Injector
7
Main Injector Improvements

• Additional RF power
• More power for extra proton intensity No new
  work
• Reduction in cycle time No new work
• Reduction in Cycle Time
• Machine tuning No new work
• Additional RF with modified RF cavities (depends
  on combination of cycle time and protons per
  cycle) No new work
• Additional magnet power supplies No new work
• New damper electronics and components. Lots of
  work, needs more?
• Necessary to go to higher intensity.
• Immediate gains of 30 or more
• Collimators to protect sensitive components from
  beam losses. No work
• Other issues associated with proton losses in
  MI No work
• Barrier RF stacking Significant but too
  little effort
• Appears promising for increasing protons
  accelerated to 120 GeV by 60. Compared to single
  batch slip stacking for pbar production will
  increase the protons to NuMI by as much as a
  factor of 2.4!
• Requires well-behaved Booster
• Requires new barrier RF systems in Main Injector.
• Fast Recycler stacking Significant but too
  little effort
• Uses barriers and an RF ramp to stack. Very
  similar to barrier stacking but possibly with
  less longitudinal emittance blow-up.

8
Intensity vs Funding
Rough correlation between the total funding
level and the number of protons which can be
accelerated to 120 GeV per year in 2005 and 2008.
9
Very Rough Costs
No contingency included which is 70-100
10
NuMI Proton Intensity Math
Note Other uses of Main Injector protons and
cycles will decrease the proton
intensity for MINOS. Test beam running will
presumably be kept small enough to keep
impact lt10. CKM or other experiments
could have larger impacts, possibly around 30-40.