Status of the Beams Division

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Status of the Beams Division

• John Marriner
• 15 October 2001

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FNAL Accelerator Complex
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Run II Luminosity Goals

• The luminosity goal for Run IIa is 2 fb-1
• Peak luminosity up to 2x1032 cm-2sec-1
• Switch to 103 bunches at 1x1032 cm-2sec-1
• Length of Run IIa is about 2 years
• The luminosity goal for Run IIaRun IIb is 15
  fb-1
• Increase antiproton intensity by 2-3
• Peak luminosity up to 5x1032 cm-2sec-1
• 103 bunch operation
• Length of Run IIb is about 4 years

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Run II Parameters
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Run IIa

• Going slowly, but not unreasonably so.
• Need to be careful that our effort is
  well-focused.
• Commissioning the Recycler is a key problem, and
  the purpose of current shutdown.
• All the accelerators require extensive work.
• 132 nsec bunch spacing requires new hardware and
  extensive commissioning time.

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Luminosity History
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Start-up ComparisonRuns Ia, Ib, and II
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Start-up ComparisonRuns Ia, Ib, and II
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Comparison toRun IIa Goals
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Proton Source

• Maintain reliability in the face of increased
  demand and deteriorating hardware
• Improve ion source (2x intensity, smaller
  emittance)
• Reduce Booster beam loss
• Operate Booster at 15 Hz

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Main Injector

• Pbar production OK
• Fixed target operation needs development
• Coalescing efficiency
• Recycler commissioning

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Recycler

• Status
• Aperture (20p mm-mrad?)
• Vacuum (ion pump test)
• Diagnostics, RF, feedback need work
• Magnetic shielding now OK?
• Cooling OK?
• Purpose of the shut down
• Alignment
• Correction magnets PS
• Magnetic shielding

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Tevatron

• Minimize beam loss emittance growth
• Increase beam intensity
• 132 nsec bunch spacing (crossing angle)
• Beam-Beam effects are a key

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7 rf bucket Bunch Spacing Crossing Angles

• A crossing angle is required for 132 nsec spacing
  but is not required for 396 nsec.
• We have a plan for the implemented the crossing
  angle that requires 3 or 4 new electrostatic
  separators.
• There is a luminosity penalty for introducing the
  crossing angle - about a factor of 2 in initial
  luminosity compared to zero crossing angle with
  the same bunch parameters
• There are uncertainties in the dynamics of the
  beam-beam interaction with this mode of operation

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Crossing angle for 132 nS Bunch Spacing
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Antiproton Source

• Stacking at high stack rates with large stacks
• Slightly larger core emittance
• Pbar production rep rate to 1.5 sec
• More protons on target
• Cooling
• Stack tail
• Core
• Beam lines acceptance and matching

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Beam Physics

• Identify study key Run II issues
• Foster communication
• Future projects
• Run seminars

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External Beams

• SY120
• NuMI
• MiniBoone
• CKM beam

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Run IIb Upgrades

• The major strategy is to increase the number of
  antiprotons
• To some extent, this is the only strategy
  collisions at the interaction regions are a major
  loss mechanism for antiprotons
• We are also attempting to compensate beam-beam
  tune shifts

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Luminosity Goals
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Luminosity Schedule
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Luminosity Formula

• The major luminosity limitations are
• The number of antiprotons ( )
• The proton beam brightness (Np/?p)
• Flt1

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More Antiprotons

• More protons on the antiproton target
• Slip stacking (1.8 x)
• Proton beam sweeping
• Better antiproton collection efficiency
• Lithium lens gradient (1.5 x)
• AP2-Debuncher aperture increases (1.5 x)
• Better cooling
• Debuncher cooling bandwidth increase
• Accumulator Stacktail Profile
• Accumulator Core bandwidth increase
• Electron cooling in the Recycler

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Slip Stacking

• Reproduced MR results with MI
• Need to push high intensity beam
• Beam loading compensation is the key

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Slip Stacking
Booster Batch 1
Booster Batch 2
RF Bucket 1
RF Bucket 2
Final RF Bucket
RF Phase Space Cartoon
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Slip Stacking Experimentin the Main Ring
beam current (dc) rf voltage fanback beam current
at 53 MHz
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Lithium Lens Gradient
Predictions
Measured Yield
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TEV 1 Antiproton Yield vs. Acceptance
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Antiproton Aperture Increases

• Largest gain if aperture is increased in regions
  upstream of the first stage of stochastic cooling
• AP2 transfer line
• Debuncher
• The goal is to increase the aperture in both
  planes from 25p mm-mrad to 40 p mm-mrad
• Beam based alignment of all magnetic elements
• requires new instrumentation
• motorized quads
• Physical aperture increases
• such as replacing beam pipe in Debuncher dipoles
  with curved beam pipe

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Run IIbPreliminary Project Schedule
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Run IIbPreliminary Project Schedule
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Run IIbPreliminary Project Schedule
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FY01 Activities for Run IIb

• Electron Cooling
• TEV Beam-Beam Compensation
• Lithium Lens development
• RD program on diffusion bonding for solid lens
• BINP liquid lithium lens RD continues
• Start program on outside company building solid
  lens
• Finish beam-sweeping
• Build 1 house of prototype Debuncher BPM system
• AP5 Lattice design?AP3/AP1/P3/P2 redesign
• Build 10 moveable quad stands for the Debuncher

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FY01 Activities for Run IIb

• Revive Slip-Stacking Low Level Electronics in
  Main Injector repeat low intensity slip
  stacking experiments
• Include Mode 1 in MI beam loading compensation

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Proton Source Projects
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Main Injector Projects
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Antiproton Source Projects
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Antiproton Source Projects
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Tevatron Projects
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Difficulties in Meeting Run IIa Run IIb Goals

• We need to finish the Run IIb upgrades before the
  LHC turns on.
• As a consequence (and in contrast to previous
  collider upgrades) the Run IIb upgrades must be
  designed, fabricated, and commisioned while we
  are still concentrating on achieving the Run IIa
  luminosity goals.
• We continue to have substantial commitments to
  fixed target experiments (NuMI, MiniBoone, 120
  GeV test beams, and RD for the separated kaon
  beam).
• Our plan requires a significant increase in BD
  manpower for Run IIb.

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More People

• Systems Departments Beam Physics
• Controls Instrumentation
• Engineering Tech Support

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Electron Cooling

• Pelletron procured, commissioned.
• Recirculation tests in progress.
• Beam tests planned for this year.
• Will initiate AIP for construction of final
  resting place for Pelletron.

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Fermilab Electron CoolingRD Project
High-voltage column with grading hoops partially
removed to show the accelerating tube (right) and
the charging chains (far center).
5 MV Pelletron installed
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Pelletron HV Conditioning and Regulation
Conditioning process of the gun-side accelerating
tube. Blue radiation under the tank, red - gun
ion pump current (mA), Green - terminal voltage.
Time axis 30 min/div. Max. voltage 4.66 MV.
Terminal voltage in a regulation regime 500
V/div, 1 min/div. Required voltage for the
Recycler cooling 4.36 MV.
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Beam-Beam Compensation

• Prototype lens constructed.
• Require operational experience to proceed with
  2nd lens.

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MiniBoone

• Detector AIP nearly complete.
• Beam line AIP nearing completion.
• Special equipment (horn, PS) progressing well.
• We want to finish construction next fiscal year
  (2002) and begin operations .

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NuMI

• New baseline
• Beamline design
• Loss
• Reliability
• Pointing?
• Successful horn tests

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A0 Photo-Injector

• Collaboration with NIU now in place
• Program advisory committee has been formed
• Experiments in progress
• Photo-Injector properties
• Flat beams
• Plasma acceleration

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CKM

• CKM has been granted stage 1 approval by the
  director on the advice of the PAC.
• We are designing the superconducting deflecting
  cavities to be used in the beam line.
• We are building a prototype system.
• We are working on the beam line design.

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BTeV

• BTeV has been granted stage 1 approval by the
  director on the advice of the PAC.
• The idea is that the experiment would run at C0
  area. Colliding beams at C0 and B0/D0 would be
  mutually exclusive.
• The laboratory intends to obtain line item
  funding for this project.
• We are working on the C0 insertion design.

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Proton Driver

• The Proton Driver report has been completed and
  has had a major impact in planning the future of
  high energy physics.
• The next step (in my view), is to develop a
  physics driven proposal that is attractive in an
  international context.
• Some RD will continue.

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Linear Collider

• The major effort is directed towards cavity
  production for NLC.
• Effort in BD is limited to preparing for a
  high-power source of X-band power.
• RD effort on NLC is subject to a cap. Most of
  the RD is carried out at SLAC.
• A study of the TESLA proposal is underway.
• There may be some work in support of the TESLA
  collaboration.

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Muon Collider /Neutrino Source

• Muon collider RD has become focused on a
  neutrino source based on a muon storage ring.
• The design studies at FNAL and BNL have been very
  useful in summarizing the issues involved in the
  construction of a neutrino source.
• The RD is in crisis because the support is
  inadequate to make progress at a reasonable rate.

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LHC/VLHC

• A modest effort in accelerator physics for LHC
  will continue.
• We hope to be involved in LHC commissioning in a
  significant way.
• There is no organized effort on VLHC in BD.
• Individual scientists are encouraged to pursue
  research interests that may be relevant to VLHC.

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SY120

• Goal is to achieve beam to Meson in early 2002.
• Finish work in F sector, A0, and enclosure B this
  shut down.
• Replace left bend (cryogenic) with EPB dipoles
  after the shut down ends.
• Resurrect slow extraction (no requirements on
  spill quality).
• The loss of Thornton Murphy leaves a big hole
  that will be difficult to fill.

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Conclusions

• Run IIa is underway, but has a long way to go to
  achieve the Run IIa goals.
• Planning for the full implementation of Run IIb
  is beginning.
• Some Run IIb RD projects are beginning to have
  some results.
• The division supports a broad range of projects.
• SY120 and MiniBoone should see beam this fiscal
  year.