Status of the Beams Division John Marriner 15 October 2001 f
f FNAL Accelerator Complex 2
f Run II Luminosity Goals l The luminosity goal for Run IIa is 2 fb-1 o. Peak luminosity up to 2 x 1032 cm-2 sec-1 o. Switch to 103 bunches at 1 x 1032 cm-2 sec-1 o. Length of Run IIa is about 2 years l The luminosity goal for Run IIa+Run IIb is 15 fb-1 o. Increase antiproton intensity by 2 -3 o. Peak luminosity up to 5 x 1032 cm-2 sec-1 o 103 bunch operation o. Length of Run IIb is about 4 years 3
f Run II Parameters 4
f Run IIa l Going slowly, but not unreasonably so. l Need to be careful that our effort is well-focused. l Commissioning the Recycler is a key problem, and the purpose of current shutdown. l All the accelerators require extensive work. l 132 nsec bunch spacing requires new hardware and extensive commissioning time. 5
f Luminosity History 6
f Start-up Comparison Runs Ia, Ib, and II 7
f Start-up Comparison Runs Ia, Ib, and II 8
f Comparison to Run IIa Goals 9
f Proton Source l Maintain reliability in the face of increased demand deteriorating hardware l Improve ion source (2 x intensity, smaller emittance) l Reduce Booster beam loss l Operate Booster at 15 Hz 10
f Main Injector l Pbar production OK l Fixed target operation needs development l Coalescing efficiency l Recycler commissioning 11
f Recycler l Status o. Aperture (20 p mm-mrad? ) o. Vacuum (ion pump test) o. Diagnostics, RF, feedback need work o. Magnetic shielding now OK? o. Cooling OK? l Purpose of the shut down o. Alignment o. Correction magnets & PS o. Magnetic shielding 12
f Tevatron l Minimize beam loss & emittance growth l Increase beam intensity l 132 nsec bunch spacing (crossing angle) l Beam-Beam effects are a key 13
f 7 rf bucket Bunch Spacing & Crossing Angles l A crossing angle is required for 132 nsec spacing but is not required for 396 nsec. l We have a plan for the implemented the crossing angle that requires 3 or 4 new electrostatic separators. o. 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 o. There are uncertainties in the dynamics of the beam interaction with this mode of operation 14
f Crossing angle for 132 n. S Bunch Spacing 15
f Antiproton Source l Stacking at high stack rates with large stacks l Slightly larger core emittance l Pbar production rep rate to 1. 5 sec l More protons on target l Cooling o. Stack tail o. Core l Beam lines acceptance and matching 16
f Beam Physics l Identify & study key Run II issues l Foster communication l Future projects l Run seminars 17
f External Beams l SY 120 l Nu. MI l Mini. Boone l CKM beam 18
f Run IIb Upgrades l The major strategy is to increase the number of antiprotons l To some extent, this is the only strategy: collisions at the interaction regions are a major loss mechanism for antiprotons FWe are also attempting to compensate beam-beam tune shifts 19
f Luminosity Goals 20
f Luminosity Schedule 21
f Luminosity Formula The major luminosity limitations are • The number of antiprotons ( ) • The proton beam brightness (Np/ p) • F<1 22
f More Antiprotons l More protons on the antiproton target o Slip stacking (~1. 8 x) o Proton beam sweeping l Better antiproton collection efficiency o Lithium lens gradient (~1. 5 x) o AP 2 -Debuncher aperture increases (~1. 5 x) l Better cooling o o Debuncher cooling bandwidth increase Accumulator Stacktail Profile Accumulator Core bandwidth increase Electron cooling in the Recycler 23
f Slip Stacking l Reproduced MR results with MI l Need to push high intensity beam l Beam loading compensation is the key 24
f Slip Stacking Booster Batch 1 Booster Batch 2 RF Bucket 1 RF Bucket 2 Final RF Bucket RF Phase Space Cartoon 25
f Slip Stacking Experiment in the Main Ring beam current (dc) rf voltage fanback beam current at 53 MHz 26
f Lithium Lens Gradient Measured Yield Predictions 27
f TEV 1 Antiproton Yield vs. Acceptance 28
f Antiproton Aperture Increases l Largest gain if aperture is increased in regions upstream of the first stage of stochastic cooling o AP 2 transfer line o Debuncher l The goal is to increase the aperture in both planes from 25 p mm-mrad to 40 p mm-mrad l Beam based alignment of all magnetic elements o requires new instrumentation o motorized quads l Physical aperture increases o such as replacing beam pipe in Debuncher dipoles with curved beam pipe 29
f Run IIb Preliminary Project Schedule 30
f Run IIb Preliminary Project Schedule 31
f Run IIb Preliminary Project Schedule 32
f FY 01 Activities for Run IIb l Electron Cooling l TEV Beam-Beam Compensation l Lithium Lens development o R&D program on diffusion bonding for solid lens o BINP liquid lithium lens R&D continues o Start program on outside company building solid lens o Finish beam-sweeping l Build 1 house of prototype Debuncher BPM system l AP 5 Lattice design AP 3/AP 1/P 3/P 2 redesign l Build 10 moveable quad stands for the Debuncher 33
f FY 01 Activities for Run IIb l Revive Slip-Stacking Low Level Electronics in Main Injector & repeat low intensity slip stacking experiments l Include Mode 1 in MI beam loading compensation 34
f Proton Source Projects 35
f Main Injector Projects 36
f Antiproton Source Projects 37
f Antiproton Source Projects 38
f Tevatron Projects 39
f Difficulties in Meeting Run IIa & Run IIb Goals l We need to finish the Run IIb upgrades before the LHC turns on. l 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. l We continue to have substantial commitments to fixed target experiments (Nu. MI, Mini. Boone, 120 Ge. V test beams, and R&D for the separated kaon beam). è Our plan requires a significant increase in BD manpower for Run IIb. 40
f More People l Systems Departments & Beam Physics l Controls & Instrumentation l Engineering & Tech Support 41
f Electron Cooling l Pelletron procured, commissioned. l Recirculation tests in progress. l Beam tests planned for this year. l Will initiate AIP for construction of final resting place for Pelletron. 42
f 5 MV Pelletron installed Fermilab Electron Cooling R&D Project High-voltage column with grading hoops partially removed to show the accelerating tube (right) and the charging chains (far center). 43
f Pelletron HV Conditioning and Regulation Conditioning process of the gun-side accelerating tube. Blue – radiation under the tank, red - gun ion pump current (m. A), 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. 44
f Beam-Beam Compensation l Prototype lens constructed. l Require operational experience to proceed with 2 nd lens. 45
f Mini. Boone l Detector AIP nearly complete. l Beam line AIP nearing completion. l Special equipment (horn, PS) progressing well. l We want to finish construction next fiscal year (2002) and begin operations. 46
f Nu. MI l New baseline l Beamline design o. Loss o. Reliability o. Pointing? l Successful horn tests 47
f A 0 Photo-Injector l Collaboration with NIU now in place l Program advisory committee has been formed l Experiments in progress o. Photo-Injector properties o. Flat beams o. Plasma acceleration 48
f CKM l CKM has been granted stage 1 approval by the director on the advice of the PAC. l We are designing the superconducting deflecting cavities to be used in the beam line. l We are building a prototype system. l We are working on the beam line design. 49
f BTe. V l BTe. V has been granted stage 1 approval by the director on the advice of the PAC. l The idea is that the experiment would run at C 0 area. Colliding beams at C 0 and B 0/D 0 would be mutually exclusive. l The laboratory intends to obtain “line item” funding for this project. l We are working on the C 0 insertion design. 50
f Proton Driver l The Proton Driver report has been completed and has had a major impact in planning the future of high energy physics. l The next step (in my view), is to develop a physics driven proposal that is attractive in an international context. l Some R&D will continue. 51
f Linear Collider l The major effort is directed towards cavity production for NLC. l Effort in BD is limited to preparing for a highpower source of X-band power. l R&D effort on NLC is subject to a “cap. ” Most of the R&D is carried out at SLAC. l A study of the TESLA proposal is underway. l There may be some work in support of the TESLA collaboration. 52
f Muon Collider / Neutrino Source l Muon collider R&D has become focused on a neutrino source based on a muon storage ring. l The design studies at FNAL and BNL have been very useful in summarizing the issues involved in the construction of a neutrino source. l The R&D is in crisis because the support is inadequate to make progress at a reasonable rate. 53
f LHC/VLHC l A modest effort in accelerator physics for LHC will continue. l We hope to be involved in LHC commissioning in a significant way. l There is no organized effort on VLHC in BD. l Individual scientists are encouraged to pursue research interests that may be relevant to VLHC. 54
f SY 120 l Goal is to achieve beam to Meson in early 2002. l Finish work in F sector, A 0, and enclosure B this shut down. l Replace left bend (cryogenic) with EPB dipoles after the shut down ends. l Resurrect slow extraction (no requirements on spill quality). L The loss of Thornton Murphy leaves a big hole that will be difficult to fill. 55
f Conclusions l Run IIa is underway, but has a long way to go to achieve the Run IIa goals. l Planning for the full implementation of Run IIb is beginning. l Some Run IIb R&D projects are beginning to have some results. l The division supports a broad range of projects. l SY 120 and Mini. Boone should see beam this fiscal year. 56
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