# Presentation: 580408

## Status of the Beams Division

- John Marriner
- 15 October 2001

## FNAL Accelerator Complex

## 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 IIa+Run 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

## Run II Parameters

## 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.

## Luminosity History

## Start-up ComparisonRuns Ia, Ib, and II

## Start-up ComparisonRuns Ia, Ib, and II

## Comparison toRun IIa Goals

## 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

## Main Injector

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

## Recycler

- Status
- Aperture (20 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

## Tevatron

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

## 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

## Crossing angle for 132 nS Bunch Spacing

## 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

## Beam Physics

- Identify & study key Run II issues
- Foster communication
- Future projects
- Run seminars

## External Beams

- SY120
- NuMI
- MiniBoone
- CKM beam

## 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

## Luminosity Goals

## Luminosity Schedule

## Luminosity Formula

- The major luminosity limitations are
- The number of antiprotons (*        *)
- The proton beam brightness (*N**p**/****p*)
*F*<1

## 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

## Slip Stacking

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

## Slip Stacking

- RF Phase Space Cartoon

- Booster Batch 1

- Booster Batch 2

- RF Bucket 1

- RF Bucket 2

- Final RF Bucket

## Slip Stacking Experimentin the Main Ring

- beam current (dc)
- rf voltage fanback
- beam current at 53 MHz

## Lithium Lens Gradient

- Measured Yield

- Predictions

## TEV 1 Antiproton Yield vs. Acceptance

## 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 25 mm-mrad to 40  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

## Run IIbPreliminary Project Schedule

## Run IIbPreliminary Project Schedule

## Run IIbPreliminary Project Schedule

## FY01 Activities for Run IIb

- Electron Cooling
- TEV Beam-Beam Compensation
- Lithium Lens development
- R&D program on diffusion bonding for solid lens
- BINP liquid lithium lens R&D 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

## 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

## Proton Source Projects

## Main Injector Projects

## Antiproton Source Projects

## Antiproton Source Projects

## Tevatron Projects

## 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 R&D for the separated kaon beam).
- Our plan requires a significant increase in BD manpower for Run IIb.

## More People

- Systems Departments & Beam Physics
- Controls & Instrumentation
- Engineering & Tech Support

## 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.

## Fermilab Electron CoolingR&D Project

- 5 MV Pelletron installed

- High-voltage column with grading hoops partially removed to show the accelerating tube (right) and the  charging chains (far center).

## 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.

## Beam-Beam Compensation

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

## 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 .

## NuMI

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

## 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

## 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.

## 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.

## 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 R&D will continue.

## 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.
- R&D effort on NLC is subject to a “cap.”  Most of the R&D is carried out at SLAC.
- A study of the TESLA proposal is underway.
- There may be some work in support of the TESLA collaboration.

## Muon Collider /Neutrino Source

- Muon collider R&D 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 R&D is in crisis because the support is inadequate to make progress at a reasonable rate.

## 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.

## 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.

## 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 R&D projects are beginning to have some results.
- The division supports a broad range of projects.
- SY120 and MiniBoone should see beam this fiscal year.