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US-LHC Activities in US-LHC Activities in ADAD
Tanaji SenTanaji Sen
OverviewOverview
The LHCThe LHC US-LHC Construction ProjectUS-LHC Construction Project US-LARP Goals and ActivitiesUS-LARP Goals and Activities Accelerator PhysicsAccelerator Physics InstrumentationInstrumentation Beam CommissioningBeam Commissioning LHC@FNALLHC@FNAL
The wise speak only of what they know Gandalf, Lord of the Rings
LHCLHC
Control Room
Key ParametersKey Parameters
TevatronTevatron LHCLHC
Injection EnergyInjection Energy
Top EnergyTop Energy
Particles/bunchParticles/bunch
# of bunches# of bunches
Trans. Emitt(95%)Trans. Emitt(95%)
Beam current (p)Beam current (p)
Stored Stored energy/beamenergy/beam
Peak LuminosityPeak Luminosity
150 GeV150 GeV
980 GeV980 GeV
2.7 x 102.7 x 101111
3636
20 mm-mrad20 mm-mrad
0.074 A0.074 A
1.5 MJ1.5 MJ 1.7 x 101.7 x 103232
450 GeV450 GeV
7000 GeV7000 GeV
1.15 x 101.15 x 1011 11
28082808
22.5 mm-mrad22.5 mm-mrad 0.584 A0.584 A
362 MJ362 MJ 1 x 101 x 103434
US-LHC Construction ProjectUS-LHC Construction Project
Interaction Region Quads (FNAL)Interaction Region Quads (FNAL)
Interaction Region Dipoles (BNL)Interaction Region Dipoles (BNL)
Interaction Region Cryogenic Feedboxes Interaction Region Cryogenic Feedboxes (LBL)(LBL)
Interaction Region Absorbers (LBL)Interaction Region Absorbers (LBL)
Accelerator Physics (FNAL, BNL, LBL)Accelerator Physics (FNAL, BNL, LBL) - related to IR designs and magnets- related to IR designs and magnets - ecloud, noise effects- ecloud, noise effects
Last magnets to be delivered in 2006
LHC IR Quads at FNALLHC IR Quads at FNAL
KEKCERN
MQXA MQXB MQXB MQXA
CORR
CORR
CORR
CORR
“Q3” “Q2” “Q1”
TAS
FNAL
DFBXMBXA
“D1”
LBNLBNL
FNAL quads
To IP
1st IR quad ready forshipment in May 2004
FNAL is delivering 18IR quads to the LHC All IR quads (FNAL, KEK) are cryostatted at FNALand shipped from here Last quad to be shipped in late 2006.
FNAL quads installed in FNAL quads installed in IR8IR8
Courtesy: J. Kerby
Mission Accomplished ?
US- LARPUS- LARP Goals – stated by J. Strait (2002)Goals – stated by J. Strait (2002) Extend and improve the performance of the Extend and improve the performance of the
LHC so as to maximize its scientific output in LHC so as to maximize its scientific output in support of US-CMS and US-ATLASsupport of US-CMS and US-ATLAS
Maintain and develop the US labs capabilitiesMaintain and develop the US labs capabilities so that the US can be the leader in the next so that the US can be the leader in the next generation of hadron colliders.generation of hadron colliders.
Serve as a vehicle for Serve as a vehicle for US accelerator US accelerator physicists to pursue their researchphysicists to pursue their research
Train future generationsTrain future generations of accelerator of accelerator physicists. physicists.
It is the next step in international cooperation It is the next step in international cooperation on large accelerators.on large accelerators.
Fermilab has been appointed the “Host Fermilab has been appointed the “Host Laboratory” to lead this program. Laboratory” to lead this program.
US LARP InstitutionsUS LARP InstitutionsTwo main areas: Two main areas: High field magnetsHigh field magnets Accelerator systemsAccelerator systems Accelerator Physics, Instrumentation, Accelerator Physics, Instrumentation,
Collimation, Commissioning (beam & Collimation, Commissioning (beam & hardware)hardware)
High field magnets: BNL, FNAL, LBLHigh field magnets: BNL, FNAL, LBL Accelerator Physics: BNL, FNAL, LBLAccelerator Physics: BNL, FNAL, LBL Instrumentation: BNL, FNAL, LBL, UT Instrumentation: BNL, FNAL, LBL, UT
AustinAustin Collimation: SLACCollimation: SLAC Commissioning: BNL, FNAL, LBLCommissioning: BNL, FNAL, LBL
US-LARP GoalsUS-LARP Goals Accelerator Physics and ExperimentsAccelerator Physics and Experiments - understand performance limitations of current IRs and - understand performance limitations of current IRs and
develop new designsdevelop new designs - Beam dynamics calculations and related experiments- Beam dynamics calculations and related experiments
Develop high performance magnets for new higher Develop high performance magnets for new higher luminosity IRsluminosity IRs
- large-aperture, high gradient quadrupoles using Nb- large-aperture, high gradient quadrupoles using Nb33SnSn - high field beam separation dipoles and strong correctors- high field beam separation dipoles and strong correctors
Develop advanced beam diagnostics and Develop advanced beam diagnostics and instrumentationinstrumentation
- luminosity monitor, tune feedback, Schottky monitor, - luminosity monitor, tune feedback, Schottky monitor, rotatable collimatorsrotatable collimators
- other systems as needed for improving LHC performance- other systems as needed for improving LHC performance
CommissioningCommissioning - participate in the sector test and LHC beam commissioning - participate in the sector test and LHC beam commissioning - commission hardware delivered by the US- commission hardware delivered by the US
IR UpgradeIR Upgrade
Luminosity and IR upgradeLuminosity and IR upgrade
An IR upgrade is a An IR upgrade is a straightforward way straightforward way to increase the to increase the luminosity – by a luminosity – by a factor of 2-3factor of 2-3
It must also deal with It must also deal with higher beam currents higher beam currents and 10 times larger and 10 times larger debris power at debris power at L=10L=103535cmcm-2-2ss-1-1
Several optics design Several optics design issuesissues
~50% of LARP effort ~50% of LARP effort is in IR magnet designis in IR magnet design
A luminosity upgrade will be required around ~2015 to keep the LHC physics program productive.
J. Strait )(.*4
FI
NL
N
b
Quadrupoles 1Quadrupoles 1stst option optionAdvantagesAdvantages Allows smaller β*, Allows smaller β*,
minimizes aberrations. minimizes aberrations. Lower accumulation of Lower accumulation of
charged particle debris charged particle debris from the IP.from the IP.
Operational experience Operational experience from the first years of from the first years of running.running.
DisadvantagesDisadvantages More parasitic beam-beam More parasitic beam-beam
interactions.interactions. Crossing angle has to Crossing angle has to
increase as 1/√β* increase as 1/√β* IR correction systems act IR correction systems act
on both beams on both beams simultaneouslysimultaneouslyBaseline Design
Dipoles 1Dipoles 1stst – 2 options – 2 optionsAdvantagesAdvantages Fewer parasitic interactions. Fewer parasitic interactions. Correction systems act on Correction systems act on
single beams.single beams. No feed-down effects in the No feed-down effects in the
quadsquads
DisadvantagesDisadvantages Large energy deposition in Large energy deposition in
the the dipoles. dipoles. Beta functions are larger → Beta functions are larger → increases aberrations.increases aberrations. Longer R&D time for dipolesLonger R&D time for dipoles Longer commissioning time Longer commissioning time after the upgradeafter the upgrade..
Triplets
Doublets
Optics SolutionsOptics Solutions
Quads first
Dipoles first: triplets Dipoles first: doublets
βMax = 9 km
βMax = 27 kmβMax = 25 km
LARP magnet program aims to build 15T pole tip fields
J. Johnstone, TS
IR Design IssuesIR Design Issues → → Luminosity Luminosity ReachReach Requirements on magnet fields and apertures Optically matched designs at all stages Energy deposition Beam-beam interactions Chromaticity and non-linear correctors, field quality Dispersion correction Susceptibility to noise, misalignment, ground motion; emittance growth Closest approach of magnets to the IP (L*) Impact of Nb3Sn magnets, e.g flux jumps R&D time required to develop the most critical R&D time required to develop the most critical hardware and to integrate it in the LHChardware and to integrate it in the LHC
….. All need to be considered in defining the luminosity reach
Towards a Reference Baseline Towards a Reference Baseline DesignDesign
Proposal by F. Ruggiero (CERN)Proposal by F. Ruggiero (CERN) ““Define a Baseline, i.e. a forward looking Define a Baseline, i.e. a forward looking
configuration which we are reasonably configuration which we are reasonably confident can achieve the required LHC confident can achieve the required LHC luminosity performance and can be used to luminosity performance and can be used to give an accurate cost estimate by mid-end give an accurate cost estimate by mid-end 2006 in a 2006 in a Reference Design ReportReference Design Report
Identify Alternative ConfigurationsIdentify Alternative Configurations Identify R&D toIdentify R&D to - support the baseline- support the baseline - develop the alternatives”- develop the alternatives”
Separately, the LARP magnet program has been tasked to deliver a working prototype of a Nb3Sn quadrupole by 2009.
Wire Compensation of Wire Compensation of beam-beam beam-beam interactionsinteractions
Long-range Long-range interactionsinteractions
Long-range beam-Long-range beam-beam interactions are beam interactions are expected to affect LHC expected to affect LHC performance – based performance – based on Tevatron on Tevatron observations and LHC observations and LHC simulationssimulations
Wire compensator is Wire compensator is proposed to mitigate proposed to mitigate their impacttheir impact
RHIC has a 2 ring RHIC has a 2 ring layout like the LHC – layout like the LHC – can be used to test can be used to test the principlethe principle
Difference in kicks between a round beam and a wire < 1% beyond 3 sigma
Wire compensation in RHIC and Wire compensation in RHIC and LHCLHCRHIC LHC
Location of wire compensatorsInstallation in Summer 2006
IP6 Reserved for wire compensatorsIP
To be installed if required to improveperformance.Feasibility would determine upgrade path
RHIC beam-beam RHIC beam-beam experimentsexperiments
Motivation for experimentsMotivation for experiments: Test of wire : Test of wire compensation in 2007compensation in 2007
Determine if a single parasitic causes beam losses Determine if a single parasitic causes beam losses that need to be compensatedthat need to be compensated
Experiments in 2005 and 2006Experiments in 2005 and 2006 Remote participation at FNAL via logbookRemote participation at FNAL via logbook Motivation for simulationsMotivation for simulations: Tests and : Tests and
improvements of codes, predictions of observations improvements of codes, predictions of observations in 2006 and of wire compensationin 2006 and of wire compensation
Several groups: FNAL, SLAC, LBL, University of Several groups: FNAL, SLAC, LBL, University of KansasKansas
(coordinated at FNAL)(coordinated at FNAL) Website: Website: http://www-http://www-ap.fnal.gov/~tsen/RHICap.fnal.gov/~tsen/RHIC
Beam-beam Experiments Beam-beam Experiments and Simulations (2006)and Simulations (2006)
Simulated lifetimes show a linear dependence on the beam separation
Beam lifetime responds to vertical separation but vertical separation 4σ (1st study – April 5th, 2006) 4 studies in all (April-May) to explore larger separations and tune space Analysis to find dependence on beam separation in progress
FNAL Simulations
V. Ranjbar, TS
Wire Compensator in RHICWire Compensator in RHIC
1 unit in each 1 unit in each ringring
2.5m long2.5m long Currents Currents
between 3.8 between 3.8 – 50 A– 50 A
Vertically Vertically movable over movable over 65mm65mm
Install in Install in Summer Summer 20062006
Pulsed WiresPulsed Wires Required for bunch Required for bunch
to bunch to bunch compensation – compensation – PACMAN bunchesPACMAN bunches
Challenges are the Challenges are the high pulse rate and high pulse rate and turn to turn stability turn to turn stability tolerancestolerances
StrengthStrength
Pulse ratePulse rate120 A-m120 A-m
439 kHz439 kHz
Turn to turn Turn to turn amplitude amplitude stabilitystability
Turn to turn Turn to turn timing timing stabilitystability
1010-4-4
0.04 nsec0.04 nsec
Open Design Challenge
LHC bunch pattern
Pulse pattern
Energy DepositionEnergy Deposition
Energy depositionEnergy deposition Primary source of radiation in the IR magnets: Primary source of radiation in the IR magnets:
pp collisions, ~ Luminositypp collisions, ~ Luminosity Tevatron: debris power ~ 2 WTevatron: debris power ~ 2 W LHC at 10LHC at 103535cmcm-2-2ss-1-1, debris power ~ 9kW, debris power ~ 9kW
Energy deposition is viewed as the major Energy deposition is viewed as the major constraint on the IR upgradeconstraint on the IR upgrade
Could be key in deciding between quads Could be key in deciding between quads first or dipoles first.first or dipoles first.
Other sources include operational beam losses Other sources include operational beam losses (e.g. beam gas scattering) and accidental (e.g. beam gas scattering) and accidental losses (e.g. misfiring of abort kickers)losses (e.g. misfiring of abort kickers)
Energy Deposition Issues & Energy Deposition Issues & ConstraintsConstraints
Quench stabilityQuench stability→→ Peak power density Peak power density Require ERequire Epeakpeak to be below the quench limit by a factor of to be below the quench limit by a factor of
33
Magnet lifetime Magnet lifetime →→ peak radiation dose and lifetime limits peak radiation dose and lifetime limits for various materialsfor various materials
Baseline LHC: expect lifetime ~ 7 years for IR magnetsBaseline LHC: expect lifetime ~ 7 years for IR magnets Upgrade LHC: requires new radiation hard materialsUpgrade LHC: requires new radiation hard materials
Dynamic heat loads Dynamic heat loads →→ Power dissipation and cryogenic Power dissipation and cryogenic implicationsimplications
Require heat load < 10 W/mRequire heat load < 10 W/m
Residual dose rates Residual dose rates →→ hands on maintenance hands on maintenance Require residual dose rates < 0.1 mSv/hrRequire residual dose rates < 0.1 mSv/hr
Dedicated system of charged particle and neutral Dedicated system of charged particle and neutral absorbers in the IRsabsorbers in the IRs
Energy Deposition: Open Mid-plane Energy Deposition: Open Mid-plane DipoleDipole
ED issues constrain the dipole design to have no coils in the mid-plane
Εpeak in SC coils ~0.4mW/g, below the quench limit
Estimated lifetime based on displacements per atom is ~10 years
Dipole design will require significant R&D, further LARP design work postponed
R. Gupta (BNL)
N. Mokhov
Quadrupole first designQuadrupole first design Without
mitigation, Epeak > 4 mW/g. Target value is ~1.7mW/g
Mitigation by thick inner liner
Stainless steel liners are not adequate
Thick Tungsten-Rhenium liner reduces
Epeak ~ 1.2 mW/gI. Rakhno
Tertiary CollimatorsTertiary Collimators
Designed to protect the detector and Designed to protect the detector and IR components from operational and IR components from operational and accidental beam lossesaccidental beam losses
N. Mokhov
Similar collimator used at A48 in the Tevatron to protect against abort kicker misfire
For the LHC propose 1m long Tungsten or Copper collimator upstream of neutral absorber
To IP
LHC InjectorLHC Injector
LHC Injector in the LHC LHC Injector in the LHC tunneltunnel Injector will accelerate beams from 0.45TeV Injector will accelerate beams from 0.45TeV
to ~1.5TeVto ~1.5TeV - Field quality of LHC better at 1.5GeV- Field quality of LHC better at 1.5GeV - Space charge effects lower, may allow - Space charge effects lower, may allow higher intensity buncheshigher intensity bunches - Could allow easier transition to LHC - Could allow easier transition to LHC
doublerdoubler
The injector will be installed in the LHC The injector will be installed in the LHC tunnel during scheduled LHC shutdownstunnel during scheduled LHC shutdowns
Return to the standard SPS injection into the Return to the standard SPS injection into the LHC will be possibleLHC will be possible
The main magnets will be the type of super-The main magnets will be the type of super-ferric combined function magnets proposed ferric combined function magnets proposed for the VLHC I.for the VLHC I. H. Piekarz (TD)
LHC Injector (LER)LHC Injector (LER)
VLHC low-field magnetVLHC low-field magnet
0.6 T (injection) 0.6 T (injection) → 1.6 T→ 1.6 T
Vertical distance between LER and LHCbeams is 1.35m
Beam TransferBeam Transfer
Fast pulsing magnets (PM) Fast pulsing magnets (PM) have to be turned off within have to be turned off within 3 micro-secs after LHC is 3 micro-secs after LHC is filled.filled.
CERN Workshop October 2006CERN Workshop October 2006--- what is not surrounded byuncertainty cannot be the truth R.P. Feynman
Sequence: SPS-> Injector -> LHC
InstrumentationInstrumentation
Schottky Monitor
Tune and Chromaticity Feedback
New Initiatives
Schottky Monitor at the Schottky Monitor at the TevatronTevatron
Allows measurements of:Allows measurements of:
Tunes from peak Tunes from peak positionspositions
Momentum spread Momentum spread from average widthfrom average width
Beam-beam tune Beam-beam tune spread of pbarsspread of pbars
Chromaticity from Chromaticity from differential widthdifferential width
Emittance from Emittance from average band poweraverage band power
Schottky Monitor Schottky Monitor DesignDesign
Schottky Monitor will Schottky Monitor will provide unique provide unique capabilitiescapabilities– Only tune Only tune
measurement during measurement during the storethe store
– Bunch-by-bunch Bunch-by-bunch measurement of measurement of parameters such as parameters such as Tune, ChromaticityTune, Chromaticity
– Average Average measurements as wellmeasurements as well
– Momentum spread & Momentum spread & emittanceemittance
Non invasive TechniqueNon invasive Technique Diagnosis of beam-beam Diagnosis of beam-beam
effects and electron effects and electron cloudcloud
R. Pasquinelli, A. Jansson
4 Monitors to be installed in the LHC, Summer 2006
Tune and Chromaticity feedbackTune and Chromaticity feedback
GoalsGoals Control the tune during the Control the tune during the
acceleration ramp to avoid acceleration ramp to avoid beam lossbeam loss
Control the chromaticity Control the chromaticity during the snapback at start during the snapback at start of rampof ramp
PLL method: excite the PLL method: excite the beam close to the tune and beam close to the tune and observe the resonant beam observe the resonant beam transfer function transfer function
Then used in a feedback Then used in a feedback system to regulate the system to regulate the quadrupole current and quadrupole current and tunetune
Measurement in RHIC with tunefeedback – tune changes ~ 0.001
Tune & chromaticity at the Tune & chromaticity at the TevatronTevatron
The Direct Diode Detection The Direct Diode Detection method (3D BBQ) from method (3D BBQ) from CERN implemented in the CERN implemented in the Tevatron – complements Tevatron – complements tune measurements from tune measurements from the Schottky monitors. More the Schottky monitors. More sensitive than the Schottky.sensitive than the Schottky.
This 3D BBQ has been used This 3D BBQ has been used to measure the to measure the chromaticity with a method chromaticity with a method due to D. McGinnis.due to D. McGinnis.
Interest in implementing Interest in implementing this method at RHIC and this method at RHIC and the SPSthe SPS
C.Y. Tan
Phase Modulation On
Phase Modulation Off
New FNAL Initiatives - New FNAL Initiatives - proposedproposed
AC Dipole (A. Jansson)AC Dipole (A. Jansson) Electron lens compensation of Electron lens compensation of
head-on interactions (V. Shiltsev)head-on interactions (V. Shiltsev) Crystal collimation (N. Mokhov)Crystal collimation (N. Mokhov) Measure field fluctuations in Measure field fluctuations in
magnets (V. Shiltsev)magnets (V. Shiltsev)
CommissioningCommissioning
LHC Plans
LARP involvement
LHC@FNAL
LHC Commissioning PlanLHC Commissioning Plan
I. Pilot physics runI. Pilot physics runFirst collisionsFirst collisions43 bunches, no crossing angle, no squeeze, moderate 43 bunches, no crossing angle, no squeeze, moderate
intensitiesintensitiesPush performance (156 bunches, partial squeeze in 1 and 5, Push performance (156 bunches, partial squeeze in 1 and 5,
push intensity)push intensity)Performance limit 10Performance limit 103232 cm cm-2-2 s s-1-1 (event pileup) (event pileup)
II. 75ns operationII. 75ns operation Establish multi-bunch operation, moderate intensitiesEstablish multi-bunch operation, moderate intensitiesRelaxed machine parameters (squeeze and crossing angle)Relaxed machine parameters (squeeze and crossing angle)Push squeeze and crossing angle Push squeeze and crossing angle Performance limit 10Performance limit 103333 cm cm-2-2 s s-1-1 (event pileup) (event pileup)
III. 25ns operation IIII. 25ns operation INominal crossing angleNominal crossing anglePush squeezePush squeezeIncrease intensity to 50% nominal Increase intensity to 50% nominal Performance limit 2 10Performance limit 2 103333 cm cm--
22 s s-1-1
IV. 25ns operation IIIV. 25ns operation IIPush towards nominal performancePush towards nominal performance
Stage I II IVIII
No beam Beam Beam
R. Bailey (CERN)
Beam Instrumentation – R.Garoby, R.Jones
Activity Responsible Other CERN LARP
ScreensE.BravinA.Guerrero
H.Burkhardt (AP)G.Arduini (AP)
BCTP.OdierD.BelohradM.Ludwig
H.Burkhardt (AP)J.Jowett (AP)
BPM and orbitR.JonesL.Jensen
J.Wenninger (OP)W.Herr (AP)I.Papaphilippou (AP)
BLMB.DehningE.HolzerS.Jackson
R.Assmann (AP)H.Burkhardt (AP)B.Jeanneret (AP)S.Gilardoni (AP)
PLL for Q, Q’, CR.JonesM.GasiorP.Karlsson
S.Fartoukh (AP)O.Berrig (AP)J.Wenninger (OP)
X
Profile monitorsS.HutchinsJ.KoopmanA.Guerrero
H.Burkhardt (AP)S.Gilardoni (AP)M.Giovannozzi (AP)
XX
Schottky monitorsF.Caspers (RF)R.JonesS.Bart-Pedersen
E.Metral (AP)C.Carli (AP)F.Zimmermann (AP)
X
Luminosity monitorsE.BravinS.Bart-Pedersen
R.Assmann (AP)F.Zimmermann (AP)
X
Expression of Interest Expression of Interest FormForm
Please respond to Elvin Harms by June Please respond to Elvin Harms by June 11stst
In anticipation of LHC-related studies using the SPS in the coming months and commissioning next year, LARP is soliciting interest for involvement in same.
http://larp.fnal.gov/commissioningForm.html
is the link for you to register your interest in being part of this effort.
SPS studies – test LHC SPS studies – test LHC issuesissues
LHCLHC collimatorcollimator teststests LSS6 commissioning LSS6 commissioning TI8 extraction test TI8 extraction test LSS4/LSS6 interleavedLSS4/LSS6 interleaved LHC beam lifetime LHC beam lifetime LHC orbit feedback LHC orbit feedback BBLR BBLR – – beam-beam compensation beam-beam compensation LHC BLM tests in the PSB LHC BLM tests in the PSB --- sample of studies planned--- sample of studies planned
From G. Arduini (CERN)From G. Arduini (CERN)
LARP plans for Beam LARP plans for Beam CommissioningCommissioning
Refining areas of involvement, identifying CERN counterparts ~15 people signed up (across all 4 labs)
LARP presence during SPS run in Summer ’06 3 FNAL people participating, room for a few more
Sector test presence planned About 2 weeks, late 2006 – early 2007
Software effort In support of instruments and control room here
Planning for long-term visits during LHC commissioning
E. Harms
What is LHC@FNAL?What is LHC@FNAL?• A PlaceA Place
• That provides access to information in a manner that is similar That provides access to information in a manner that is similar to what is available in control rooms at CERNto what is available in control rooms at CERN
• Where members of the LHC community can participate remotely Where members of the LHC community can participate remotely in CMS and LHC activitiesin CMS and LHC activities
• A Communications ConduitA Communications Conduit• Between CERN and members of the LHC community located in Between CERN and members of the LHC community located in
North AmericaNorth America
• LARP use: Training before visiting CERN, Participating in LARP use: Training before visiting CERN, Participating in Machine Studies, Analysis of performance, “Service after Machine Studies, Analysis of performance, “Service after the Sale” of US deliverablesthe Sale” of US deliverables
• An Outreach toolAn Outreach tool• Visitors will be able to see current LHC activitiesVisitors will be able to see current LHC activities
• Visitors will be able to see how future international projects in Visitors will be able to see how future international projects in particle physics can benefit from active participation in projects particle physics can benefit from active participation in projects at remote locations.at remote locations.
Planned Opening in September 2006Planned Opening in September 2006 E. Gottschalk
LHC@FNALLHC@FNALYou can observe a lot just bywatching Yogi Berra
Control Room at CERNControl Room at CERN
Started operation on Feb 1, 2006
13 operators on shift + experts
LHC ChallengesLHC Challenges Machine protectionMachine protection Quench protection e.g at 7 TeV, fast Quench protection e.g at 7 TeV, fast
losses < 0.0005% bunch intensitylosses < 0.0005% bunch intensity Collimation (400 degrees of freedom!)Collimation (400 degrees of freedom!) Controlling 2808 bunchesControlling 2808 bunches Snapback and rampSnapback and ramp ΔΔQ’ (snapback) ~ 90, Q’ (snapback) ~ 90, ΔΔQ’ (ramp & squeeze) ~ 320 Q’ (ramp & squeeze) ~ 320 ----- -----
Summary of LARP Summary of LARP activitiesactivities Optics design of IR upgradeOptics design of IR upgrade Energy deposition calculations in IR magnetsEnergy deposition calculations in IR magnets Design of tertiary collimatorsDesign of tertiary collimators Beam-beam and wire compensation Beam-beam and wire compensation
experimentsexperiments Optics design of a proposed LHC injectorOptics design of a proposed LHC injector Design of Schottky MonitorDesign of Schottky Monitor Tests of tune and chromaticity trackingTests of tune and chromaticity tracking Proposed new initiatives: AC dipole, E-lens, Proposed new initiatives: AC dipole, E-lens,
Crystal collimation, Field fluctuationsCrystal collimation, Field fluctuations Participation in SPS and LHC sector testsParticipation in SPS and LHC sector tests LHC beam commissioningLHC beam commissioning LHC@FNALLHC@FNAL
Web pagesWeb pages AD: larp.fnal.govAD: larp.fnal.gov
US-LARP: dmsUS-LARP: dms.uslarp.org.uslarp.org
LARP document databaseLARP document database larpdocs.fnal.govlarpdocs.fnal.gov
FNAL-TD, BNL, LBL, SLAC also have FNAL-TD, BNL, LBL, SLAC also have web pages – links from the uslarp pageweb pages – links from the uslarp page
E. McCrory
CreditsCredits Accelerator Physics: J. Johnstone, Accelerator Physics: J. Johnstone,
N. Mokhov, I. Rakhno, V. RanjbarN. Mokhov, I. Rakhno, V. Ranjbar
Instrumentation: A. Jansson, R. Instrumentation: A. Jansson, R. Pasquinelli, V. Shiltsev, C.Y. TanPasquinelli, V. Shiltsev, C.Y. Tan
Commissioning: E. Harms, E. Commissioning: E. Harms, E. McCrory, J. Slaughter, M. SyphersMcCrory, J. Slaughter, M. Syphers
BackupsBackups
US-LARP activities in US-LARP activities in 20062006
Accelerator PhysicsAccelerator Physics FNAL: IR design, Beam-beam compensation, Energy FNAL: IR design, Beam-beam compensation, Energy
deposition, tertiary collimatorsdeposition, tertiary collimators BNL: Beam-beam compensationBNL: Beam-beam compensation LBL: Electron cloudLBL: Electron cloud
InstrumentationInstrumentation FNAL: Schottky monitor, tune feedbackFNAL: Schottky monitor, tune feedback BNL: Tune feedbackBNL: Tune feedback LBL: Luminosity monitorLBL: Luminosity monitor
Rotating collimatorsRotating collimators – SLAC – SLAC
MagnetsMagnets High field quads: FNAL, BNL, LBLHigh field quads: FNAL, BNL, LBL
Commissioning Commissioning – all labs– all labs
Features of Doublet Features of Doublet OpticsOptics Symmetric about IP from Q1 to Q3, anti-symmetric Symmetric about IP from Q1 to Q3, anti-symmetric
from Q4 onwardsfrom Q4 onwards Q1, Q2 are identical quads, Q1T is a trim quad (125 Q1, Q2 are identical quads, Q1T is a trim quad (125
T/m). L(Q1) = L(Q2) = 6.6 mT/m). L(Q1) = L(Q2) = 6.6 m Q3 to Q6 are at positions different from baseline Q3 to Q6 are at positions different from baseline
opticsoptics All gradients under 205 T/mAll gradients under 205 T/m At collision, At collision, ββ**xx= 0.462m, = 0.462m, ββ**yy = 0.135m, = 0.135m, ββ**effeff= 0.25m= 0.25m Same separation in units of beam size with a smaller Same separation in units of beam size with a smaller
crossing angle crossing angle ΦΦEE = √( = √(ββ**RR/ / ββ**EE) ) ΦΦR R = 0.74 = 0.74 ΦΦR R Luminosity gain compared to round beamsLuminosity gain compared to round beams
Including the hourglass factor,
LHC Commissioning PlanLHC Commissioning Plan
Where are we ?Where are we ?
Overall strategy OKStage IStage I 43 bunches 43 bunchesStage IIStage II 75ns75nsStage IIIStage III 25ns low I25ns low IStage IVStage IV 25ns high I25ns high I
Stage I looked atStage I looked at
Some details behind
Need to make this into a detailed Need to make this into a detailed commissioning plancommissioning plan
Best developed by the people who will Best developed by the people who will implementimplement itit
Machine Machine coordinators/Commissioners/EICs + coordinators/Commissioners/EICs + Accelerator SystemsAccelerator Systems
Work through 2006 (suggest 20% Work through 2006 (suggest 20% activity)activity)
1 Injection and First turnInjection and First turn
2 Circulating beam, RF Circulating beam, RF capturecapture
3 450 GeV: initial 450 GeV: initial commissioningcommissioning
4 450 GeV: detailed 450 GeV: detailed measurementsmeasurements
5 450 GeV: 2 beams450 GeV: 2 beams
6 Nominal cycleNominal cycle
7 Snapback – single beamSnapback – single beam
8 Ramp – single beamRamp – single beam
9 Single beam at physics Single beam at physics energyenergy
10
Two beams to physics Two beams to physics energyenergy
11 PhysicsPhysics
12 Commission squeezeCommission squeeze
13 Physics partially squeezedPhysics partially squeezed
From R. Bailey (CERN)
Machine protectionMachine protection Metal damageMetal damage 450 GeV: 50 nominal bunches450 GeV: 50 nominal bunches 7 TeV: 7 x 107 TeV: 7 x 1099, about 6% of 1 bunch, about 6% of 1 bunch Quench protectionQuench protection Fast losses 450 GeV: 10Fast losses 450 GeV: 1099, 7TeV: 5x10, 7TeV: 5x1055
During abort 450GeV: 1.4x10During abort 450GeV: 1.4x1099 p/m in p/m in gapgap
7TeV: 2x107TeV: 2x1066 p/m in gap p/m in gap Collimator damageCollimator damage Fast losses 450 GeV: 260 bunchesFast losses 450 GeV: 260 bunches 7 TeV: 4 bunches7 TeV: 4 bunches
LHC Sector test with LHC Sector test with beambeam
3.3 km of the LHC including one experiment insertion and a full arc
LHC@FNALLHC@FNAL
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