240 likes | 384 Views
Snowmass 2001. Overview of IR issues: Hadron Colliders. Fulvia Pilat. T1 Working Group Snowmass, July 3, 2001. Outline. Overview of existing, near and far future hadron colliders (and planned upgrades) Review key IR issues VLHC IR’s : new “kid” in town…
E N D
Snowmass 2001 Overview of IR issues:Hadron Colliders Fulvia Pilat T1 Working Group Snowmass, July 3, 2001
Outline • Overview of existing, near and far future hadron colliders (and planned upgrades) • Review key IR issues • VLHC IR’s : new “kid” in town… Stage 1 (LF) and Stage 2(HF) new “regime” for hadron colliders (synchrotron radiation, flat beams ?, beam vs. pipe size, etc.) • Hadron IR R&D • Plans for “hadron” T1 sessions Overview of IR issues: hadron colliders
The hadron collider landscape Upgrade Tevatron Luminosity (Nb, pbar) 2001-20 07 Plans RHIC Luminosity (b*, Nb, e-cooling) 2002-2005 LHC Luminosity (b*, Nb, Ib ) 2008-2010 Overview of IR issues: hadron colliders
HI - Luminosity Increase Nb bunch spacing Decrease b* IR triplet Increase N xlim, IBS Decrease e xlim, IBS Phase 1/RDM+ Phase 2/RHIC II/ For IBS: e- cooling Overview of IR issues: hadron colliders
RHIC Upgrade - Parameters Overview of IR issues: hadron colliders
Electron cooling for RHIC LINAC e-cooling well established at low-energy collaboration RHIC: first high energy, bunched, collider BNL-Novosibirsk For 100 GeV/u beams: Ee-= 54 MeV; Ie-= 3 A peak / ~100 mA ave high brightness, high power, energy recuperatingsuperconducting linac Electron cooling scenarios need careful optimization Overview of IR issues: hadron colliders
Hadron collider IR issues • Design layout, footprints, flexibility, upgrade • Components magnets, cryostats, powering • Perf. limitations LR beam-beam, field quality IR magnets alignment • Corrections local linear and nonlinear, orbit, feedback beam-beam compensation • Operations b* squeeze, x-ing angles, rapid refills IR components accessibility, reliability cryo sectors warmup-recool, quench recovery • Experiments integration, energy deposition, backgrounds collimation Experience from existing machines - Examples from VLHC study Overview of IR issues: hadron colliders
IR design – VLHC Stage 1 Triplet optics Antisymmetric Triplets 300 T/m 4 matching quads 70 T/m Dm fixed b* : 6 0.3 m Crossing angle +/- 77 mrad 10 s separation at the first parasitic crossing Overview of IR issues: hadron colliders
IR design – VLHC Stage 2 Doublet – symmetric Similar to e+e- rings Doublet 400 T/m 600 T/m Dm fixed b*v : 7.12 0.37 m b*h : 71.2 3.7 m Triplet – antisymmetric Similar to Stage 1 optics Triplets 400 T/m Matching quads 400 T/m Dm fixed b* : 12 0.5 m X-ing +/- 28.8 mrad 10 s separation Overview of IR issues: hadron colliders
VLHC 2: flat versus round VLHC 2 is the first (hadron) collider to operate in SR regime damping time < store time Consider flat beam option k = ey/ex << 0.1 possible • Advantages • Doublet more efficient (bmax) • Fewer parasitic collisions • Disadvantages • Doublet magnet design hard • Neutrons from IP hit the conductor • Lack of (lower) energy flexibility • Maintain vertical emittance Overview of IR issues: hadron colliders
VLHC Stage 2: flat vs. round Issue very much open….what is a fair comparison, etc.. Overview of IR issues: hadron colliders
IR components • Magnets very high gradient quads SSC US-LHC VLHC • IR assemblies – cryostats RHIC (10cold masses) US-LHC (3 labs) • Absorbers, Collimators • Powering systemsaccuracy reproducibility stability (LHC 20-100 ppm) tracking Overview of IR issues: hadron colliders
Performance limitations • Field quality in IR magnets (triplets/doublet and separation dipoles) new “regime” with VLHC 2 beam << pipe orbit/coupling correction, feedback dp/p~5x10-5 “low’ chromatic effect (-42 units/IR) • LR beam-beam Tevatron Run II, LHC performance limited by LR beam-beam VLHC – evaluation in progress DQx,y ~ +/- 2r N Lsep/ pg SBbx,y a Lsep/SBnumber of parasitic crossings/ IR • alignment Overview of IR issues: hadron colliders
IR Correction Correction strategy: RHIC LHC VLHC IR corrector Package (skew) a0 a1 a2 a3 BPM 600T/m 600T/m Q2a Q2b 12T IP 12.1m 6m 22m 3m 12.4m 12.4m D1A D1B D2 3m Q1a Q1b 7.9m 7.9m 20m 16T 12T 2m 5.5m b0 b2 b3 b5 3m 400T/m 600T/m IR corrector Package Overview of IR issues: hadron colliders
IR Correction - RHIC • Linear (skew quads) • local IR bumps (3) • Kick+difference orbit (1) • Nonlinear • Action-kick minimization (2) • Local IR bumps (3) • Frequency analysis (4) • Cardona, Pilat, Ptitsyn • Wei • Koutchouck, Pilat, Ptitsyn • 4. Schmidt Overview of IR issues: hadron colliders
IR Correction - RHIC • IR local bumps • Measure rms orbit and tune shift vs. bump • amplitude • Determine local skew quads and nonlinear • correction settings • Implemeted in Run 2001 Overview of IR issues: hadron colliders
IR Operations • b squeeze (on the ramp, at collision) • Crossing angles • Rapid refills • Reliabilility of components • Accessibility of inner triplet cryostat • Sector-by-sector warmup/recool • Quench protection and recovery Overview of IR issues: hadron colliders
Interface machine-experiments • IR dimensions • Location of low beta quads • Beam abort • Background, shielding, collimation Analysis of backgrounds and energy deposition for Stage 2 in progress (PYTHIA simulations) Absorbers/collimation to be designed in detail Overview of IR issues: hadron colliders
Hadron IR R&D This is the goal of the workshop, but as a starting point: • High field IR magnets SC cable, magnets for flat optics, field quality • Beam correction and control Instrumentation, diagnostic, feedback Plan for beam experiments at RHIC, Tevatron (later LHC) for hadron collider R&D Existing MD plan at RHIC experiments Overview of IR issues: hadron colliders
Plan for “hadron” IR sessions • T1-T2-M4 IR magnets components • T1 Tevatron, RHIC, LHC operations • T1 M4 E4 VLHC IR-1 design, experiments • T1 M4 VLHC IR-2 design, perf. limitations • T1 T5 M4…. Beam-beam perf. limitations, corrections • T1 T5 T9 IR diagnostics corrections, operations Overview of IR issues: hadron colliders
T1 Agenda Overview of IR issues: hadron colliders
Session agenda - 1 • IR magnets M.Lamm Overview IR magnets issues & challenges R.Gupta IR magnets for VLHC P.Wanderer Power supplies for IR magnets • Tevatron, RHIC, LHC J.Marriner IR design and operational experience at the Tevatron M.Lamm Overview of LHC interaction regions J.Cardona IR design and operational experience at RHIC • VLHC IR 1 J.Johnstone Stage 1 LHC IR design N.Mokhov Energy deposition in VLHC IR Areas D.Denisov Machine-experiment interface and integration Overview of IR issues: hadron colliders
Session agenda - 2 • VLHC IR 2 S.Peggs Flat beams for Stage 2 VLHC J.Johnstone Triplet optics for Stage 2 VLHC B.Parker VLHC IR magnet separation schemes • Beam-beam see comprehensive schedule from T5 WG • IR diagnostics M.Minty Beam measurements and manipulations F.Pilat Operational correction of linear & nonlinear errors in the RHIC IR’s Overview of IR issues: hadron colliders
Conclusion(s) Let’s get down to work Overview of IR issues: hadron colliders