Fermilab’s Fermilab’s Tevatron Tevatron & Large Large Hadron Hadron Collider Collider (LHC) (LHC) (LHC) (LHC) Teruki Kamon PHYS 736 01 PHYS 736-01 1 Hadron Collisions at the Tevatron and the LHC Taken from slides by Ron Moore, Paul Derwent, Mike Syphers (FNAL) (April 2005) Modified/updated by Teruki Kamon for PHYS 627 (TAMU) and PHYS 736 (KNU) A little bit of Einstein… A little bit of Einstein… R ll th ll k ti Recall the well-known equation: M i “l l ” V 2 mc E = Measure energy in “electron volts” = eV (1 eV ≈ 1.6 x 10 −19 Joule) Measure mass in units of eV/c 2 Measure mass in units of eV/c … (1 eV/c 2 ≈ 1.78 x 10 −36 kg) …but often use units where c ≡ 1, so mass can also be measured in eV For a moving particle: Total Energy = Rest Energy + Kinetic Energy 2 2 2 2 ) ( ) ( mc pc mc E γ = + = 2 1 1 β γ − = c v ≡ β 2 2 1 mc ) ( mc E − + = γ Hadron Collisions at the Tevatron and the LHC 2 Total Energy Rest Energy Kinetic Energy Ultra-relativistic: γ >> 1 can neglect rest mass 1 mc ) ( mc E + γ Fixed Target vs. Colliders Fixed Target vs. Colliders / l l / l l w/o calculus w/o calculus Hadron Collisions at the Tevatron and the LHC 3 Fixed Target vs. Colliders Fixed Target vs. Colliders / l l / l l Fixed Target Center of Mass Energy w/ calculus w/ calculus Energy E mE s 2 = ultrarelativistic limit Head-On Collision Energy E Energy E E s 2 = Compare protons @ 1 TeV: Fixed Target: E CM = 43 GeV Collider: E CM = 2000 GeV Big advantage for colliders! ⇒ Most efficient use of beam energy for physics! Challenge to get a high collision rate to look for interesting (rare) processes Hadron Collisions at the Tevatron and the LHC 4 Fixed target still essential for secondary beams: antiprotons, kaons, µ’s, ν’s
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Fermilab’sFermilab’s TevatronTevatron &&Large Large HadronHadron Collider Collider
(LHC)(LHC)(LHC)(LHC)
Teruki KamonPHYS 736 01PHYS 736-01
1Hadron Collisions at the Tevatron and the LHC
Taken from slides by Ron Moore, Paul Derwent, Mike Syphers (FNAL) (April 2005)Modified/updated by Teruki Kamon for PHYS 627 (TAMU) and PHYS 736 (KNU)
A little bit of Einstein…A little bit of Einstein…R ll th ll k tiRecall the well-known equation:
M i “ l l ” V
2mcE =Measure energy in “electron volts” = eV
(1 eV ≈ 1.6 x 10−19 Joule)
Measure mass in units of eV/c2Measure mass in units of eV/c …
Big advantage for colliders! ⇒ Most efficient use of beam energy for physics!Challenge to get a high collision rate to look for interesting (rare) processes
Hadron Collisions at the Tevatron and the LHC 4
Fixed target still essential for secondary beams: antiprotons, kaons, µ’s, ν’s
Hadron Collisions at the Tevatron and the LHC 5
TevatronTevatron: : 29 29 Years Later…Years Later…Tevatron discovered topTevatron discovered top, but failed to do much more even though we got 50 times more data since the discovery.Wh ? A tl didWhy? Apparently we did not get high enough in energygy
All the fun stuff must be happening at a bit higher energiesenergies
LHC: next large step
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CERN Courier (July/August 2009)
Hadron Collisions at the Tevatron and the LHC 7
intσintσ intσ
A int int
3.46 x 109
crossingscrossingsSkip
Hadron Collisions at the Tevatron and the LHC 8
LuminosityLuminosityLuminosity is measure of the collision rate in a collider 2
21
4NN
fL =Luminosity is measure of the collision rate in a colliderUnits are cm− 2 s−1
LHC 7 T V 1 1 761E 07 0 999999995 9596LHC 7 TeV 1 1.761E+07 0.999999995 9596
VLHC? 100 TeV 1 1.957E+08 1 106611
1 keV = 103 eV 1 MeV = 106 eV 1 GeV = 109 eV 1 TeV = 1012 eV
Hadron Collisions at the Tevatron and the LHC 16
Mass of top quark ≈ 175 GeV
HiHi--rise Buildingrise Building
•25 keV H− ion source
Hadron Collisions at the Tevatron and the LHC 17
•750 keV Cockcroft-Walton accelerator
CockcroftCockcroft--WaltonWalton
•25 keV H− ion source
750 k V C k ft W lt l t
Hadron Collisions at the Tevatron and the LHC 18
•750 keV Cockcroft-Walton accelerator
LinacLinac
H− ionsAccelerate H− ions to 400 MeV
116 MeV Alvarez linac (201.25MHz)
Hadron Collisions at the Tevatron and the LHC 19
400 MeV side-coupled cavity linac (805 MHz)
BoosterBooster
Booster: 8 GeV SynchrotronRuns at 15 Hz
S i f i i j iStripper foil at injection removeselectrons from H− ions
Accelerates protons from 400pMeV to 8 GeV
Most protons (>75%) goingthrough Booster are delivered to
Hadron Collisions at the Tevatron and the LHC 20
through Booster are delivered toMiniBoone (eventually NuMI)
Main Injector & Recycler RingMain Injector & Recycler Ring
Main InjectorRecycler
Hadron Collisions at the Tevatron and the LHC 21
Main Injector
Main Injector (MI)Main Injector (MI)R l d M i Ri (f l i T t l)Replaced Main Ring (formerly in Tevaron tunnel)
Higher repetition rate for stacking pbarsSimultaneous stacking and fixed target running
Many operating modesPbar production: ~ 6-7 x 1012 120-GeV protons to pbar target
“Slip-stacking” – merge two booster batches of beam on 1 MI ramp cycleSlip stacking merge two booster batches of beam on 1 MI ramp cycle
“Tevatron protons/pbars”:Accelerate 8 GeV to 150 GeV
9Coalesce 7-9 proton bunches at 90% eff into “270-300 x 109 proton” bunchCoalesce 5-7 pbar bunches at 75-90% eff into “20-80 x 109 antiproton” bunch
Transfer 8-GeV protons/pbars to the RecyclerProvide protons for neutrino production
8-GeV protons for MiniBoone120-GeV protons for NuMI
Hadron Collisions at the Tevatron and the LHC 22
120-GeV protons for NuMI
120-GeV protons to Switchyard (fixed target area)
Debuncher & AccemulatorDebuncher & Accemulator
Debuncher
Two rings
A lHadron Collisions at the Tevatron and the LHC 23
Accumulator
Pbar (Antiproton) SourcePbar (Antiproton) Source
(1) > 6 x 1012 120-GeV protons per pulse strike Ni target every 2-3 sec; (2) Li lens (740 Tesla/m) collects negative secondaries; (3) Pulsed dipole “PMAG” bends pbars down AP-2 line to Debuncher
ε ≈ (14 18) x 10−6 pbars/proton on target
Hadron Collisions at the Tevatron and the LHC 24
ε ≈ (14-18) x 10 6 pbars/proton on target
Pbars “debunched”, cooled briefly in Debuncher prior to Accumulator
Depending on stack size; Limited by stochastic cooling systems in Accumulator
Transverse beam size increases linearly with stack size - That’s a drawback…In a really good 24 hour period, nearly 200 x 1010 pbars can be accumulated.
Pbar Production Rate = 3.3 x 10−12 g/day (Mpbar ≈ 1.67 x 10−24 g)
800 million years to make 1 g of antimatter!
Hadron Collisions at the Tevatron and the LHC 25
Tevatron OverviewTevatron OverviewProton-pbar collisions (Eb = 980 GeV)Proton pbar collisions (Ebeam 980 GeV)Revolution time ~ 21 µsVirtually all of the Tevatron magnets areVirtually all of the Tevatron magnets are superconducting (Cooled by liquid helium, operate at 4 K)
150 GeV beams are injected from MIProtons injected from P1 line at F17; Pbars injected from A1 line at E48
b h f d b i l i b i b36 bunches of proton and pbars circulate in same beam pipe, but separated by “electrostatic separators”3 trains of 12 bunches with 396 ns separation (see the next page)3 trains of 12 bunches with 396 ns separation (see the next page)2 low β (small beam size) intersection points (CDF and D0)8 RF cavities (near F0) to keep beam in bucket acceleration
Hadron Collisions at the Tevatron and the LHC 26
8 RF cavities (near F0) to keep beam in bucket, acceleration1113 RF buckets (53.1 MHz ⇒ 18.8 ns bucket length)
Proton Bunch PositionsProton Bunch Positions3 i f 12 b h i h 396 i3 trains of 12 bunches with 396 ns separation
Enormous and very sophisticated magnetic system:magnetic system:
1,232 14.3-m long superconducting dipole magnets keep protons in the orbit
B = 0 5 8 3 T as protons accelerateB = 0.5 – 8.3 T as protons accelerate from 450 GeV to 7 TeV
392 superconducting quadrupole magnets to focus beamsEvery magnet in sync with all others toEvery magnet in sync with all others to keep the beam runningTotal magnetic energy stored is that of Aerobus A380 flying at 700 km/h
Largest “refrigerator” in the world:Largest refrigerator in the world:40,000 tons of cold mass spread over 27 km10,000 tons of Liquid Nitrogen (at T = 80 K)
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80 K)60 tons of Liquid Helium (cools ring to final 1.9 K)
14 000 x mass of proton (14 TeV) = Collision EnergyProtons fly at 99 999999% of speed of lightProtons fly at 99.999999% of speed of light