Teruki Kamon PHYS 627. Taken from slides by Ron Moore, Paul Derwent, Mike Syphers (FNAL) (Apr 2005) Modified/updated by Teruki Kamon for PHYS 627

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Fermilab s s Tevatron & Large Hadron Collider (LHC) Teruki Kamon PHYS 67 Taken from slides by Ron Moore, Paul Derwent, Mike Syphers (FNAL) (Apr 005) Modified/updated by Teruki Kamon for PHYS 67

1 Fermilab s s Tevatron & Large Hadron Collider (LHC) Teruki Kamon PHYS 67 Taken from slides by Ron Moore, Paul Derwent, Mike Syphers (FNAL) (Apr 005) Modified/updated by Teruki Kamon for PHYS 67 Hadron Collisions at the Tevatron and the LHC 1 A little bit of Einstein Recall the well-known equation: E = Measure energy in electron volts = ev (1 ev 1.6 x Joule) Measure mass in units of ev/c (1 ev/c 1.78 x kg) but often use units where c 1, so mass can also be measured in ev For a moving particle: E = mc ( mc ) + ( pc) = γ mc Total Energy = Rest Energy + Kinetic Energy γ = Ultra-relativistic: γ >> 1 can neglect rest mass 1 1 β = mc + ( γ v β c 1 ) mc Hadron Collisions at the Tevatron and the LHC E

2 Fixed Target vs. Colliders w/o calculus Hadron Collisions at the Tevatron and the LHC 3 Fixed Target vs. Colliders w/ calculus Fixed Target Center of Mass Energy Energy E s = me ultrarelativistic limit Head-On Collision Energy E Compare 1 TeV: Fixed Target: E CM = 43 GeV Energy E Collider: E CM = 000 GeV s = E 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 Fixed target still essential for secondary beams: antiprotons, kaons, µ s, ν s Hadron Collisions at the Tevatron and the LHC 4

3 Hadron Collisions at the Tevatron and the LHC 5 σ int A σ int σ int Skip 3.46 x 10 9 crossings Hadron Collisions at the Tevatron and the LHC 6

Luminosity Luminosity is measure of the collision rate in a collider Units are cm s 1 Peak luminosity ~ 1. 10 3 cm s 1 Goal ~ 4.

frequency (more bunches) Not for Tevatron will keep using 36 bunches of protons and antiprotons Smaller beam Tevatron beams are ~30 µm wide at interaction

Luminosity Cross Section = Event Rate e.g., 1 10 3 cm s 1 10 pb = 3.

4 Luminosity Luminosity is measure of the collision rate in a collider Units are cm s 1 Peak luminosity ~ cm s 1 Goal ~ cm s cm = 1 barn; 10 3 cm s 1 = 360 nb 1 /hr To reach higher luminosity More beam May be hard Tevatron needs more antiprotons Higher collision frequency (more bunches) Not for Tevatron will keep using 36 bunches of protons and antiprotons Smaller beam Tevatron beams are ~30 µm wide at interaction points Linear colliders have nm size beams All can be hard to achieve due to instabilities that may develop Want high luminosity to study rare processes Luminosity Cross Section = Event Rate e.g., cm s 1 10 pb = 3.6 events/hr f N Hadron Collisions at the Tevatron and the LHC 7 1, L = is collision frequency N σ is beam size f N 1 N 4πσ are # particles in each beam Model of Accelerator Accelerating device + magnetic field to bring it back to accelerate again + = Hadron Collisions at the Tevatron and the LHC 8

5 Hadron Collisions at the Tevatron and the LHC 9 Where is the Fermilab? Hadron Collisions at the Tevatron and the LHC 10

6 Looking Down on the Fermilab Accelerator Complex ~5 mi. CDF D0 Hadron Collisions at the Tevatron and the LHC 11 Closely Looking Down on the Fermilab Wilson Hall Tevatron Main Injector 1 km Hadron Collisions at the Tevatron and the LHC 1

7 MiniBoone (8 GeV) NuMI (10 GeV protons) Accelerator Highest Energy Cockroft Walton Linac Booster 750 kev 400 Mev 8 GeV 10 8 Main injector 150 GeV TEVATRON 980 GeV Machine Energies (c( = 1) Comparing relativistic β, γ for electrons and protons at various energies rest mass electron 511 kev proton 938 MeV Machine KE β γ β γ Cockroft-Walton 750 kev FNAL Linac 400 MeV FNAL Booster 8 GeV Main Injector 150 GeV ILC 500 GeV Tevatron 980 GeV E LHC 7 TeV E VLHC? 100 TeV E kev = 10 3 ev 1 MeV = 10 6 ev 1 GeV = 10 9 ev 1 TeV = 10 1 ev Mass of top quark 175 GeV Hadron Collisions at the Tevatron and the LHC 14

LHC 15 Cockcroft-Walton 5 kev H ion source 750 kev

8 Hi-rise Building 5 kev H ion source 750 kev Cockcroft- Walton accelerator Hadron Collisions at the Tevatron and the LHC 15 Cockcroft-Walton 5 kev H ion source 750 kev Cockcroft-Walton accelerator Hadron Collisions at the Tevatron and the LHC 16

Linac Accelerate H ions to 400 MeV 116 MeV Alvarez linac (01.

at the Tevatron and the LHC 17 Booster Booster: 8 GeV Synchrotron Runs at

protons from 400 MeV to 8 GeV Most protons (>75%) going through Booster

9 Linac Accelerate H ions to 400 MeV 116 MeV Alvarez linac (01.5MHz) 400 MeV side-coupled cavity linac (805 MHz) H ions Hadron Collisions at the Tevatron and the LHC 17 Booster Booster: 8 GeV Synchrotron Runs at 15 Hz Stripper foil at injection removes electrons from H ions Accelerates protons from 400 MeV to 8 GeV Most protons (>75%) going through Booster are delivered to MiniBoone (eventually NuMI) Hadron Collisions at the Tevatron and the LHC 18

Main Injector & Recycler Ring Recycler Main Injector Hadron Collisions at the Tevatron and the LHC 19 Main Injector (MI) Replaced Main Ring (formerly in Tevaron tunnel) Higher repetition rate for

10 Main Injector & Recycler Ring Recycler Main Injector Hadron Collisions at the Tevatron and the LHC 19 Main Injector (MI) Replaced Main Ring (formerly in Tevaron tunnel) Higher repetition rate for stacking pbars Simultaneous stacking and fixed target running Many operating modes Pbar production: ~ 6-7 x GeV protons to pbar target Slip-stacking merge two booster batches of beam on 1 MI ramp cycle Tevatron protons/pbars : Accelerate 8 GeV to 150 GeV Coalesce 7-9 proton bunches at 90% eff into x 10 9 proton bunch Coalesce 5-7 pbar bunches at 75-90% eff into 0-80 x 10 9 antiproton bunch Transfer 8-GeV protons/pbars to the Recycler Provide protons for neutrino production 8-GeV protons for MiniBoone 10-GeV protons for NuMI 10-GeV protons to Switchyard (fixed target area) Hadron Collisions at the Tevatron and the LHC 0

Debuncher & Accemulator Debuncher Two rings Accumulator Hadron Collisions at

protons per pulse strike Ni target every -3 sec; () Li lens (740 Tesla/m)

line to Debuncher ε (14-18) x 10 6 pbars/proton on target Pbars debunched,

11 Debuncher & Accemulator Debuncher Two rings Accumulator Hadron Collisions at the Tevatron and the LHC 1 Pbar (Antiproton) Source (1) > 6 x GeV protons per pulse strike Ni target every -3 sec; () Li lens (740 Tesla/m) collects negative secondaries; (3) Pulsed dipole PMAG bends pbars down AP- line to Debuncher ε (14-18) x 10 6 pbars/proton on target Pbars debunched, cooled briefly in Debuncher prior to Accumulator Hadron Collisions at the Tevatron and the LHC

Stack rate = 6-14 ma/hr Pbar (Antiproton) Source Depending on stack size; Limited by stochastic cooling systems in Accumulator Transverse beam size increases linearly with stack size - That s a

12 Stack rate = 6-14 ma/hr Pbar (Antiproton) Source 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 4 hour period, nearly 00 x pbars can be accumulated. Pbar Production Rate = 3.3 x 10 1 g/day (M pbar 1.67 x 10 4 g) 800 million years to make 1 g of antimatter! Hadron Collisions at the Tevatron and the LHC 3 Tevatron Overview Proton-pbar collisions (E beam = 980 GeV) Revolution time ~ 1 µs 150 GeV beams are injected from MI Virtually all of the Tevatron magnets are superconducting (Cooled by liquid helium, operate at 4 K) Protons injected from P1 line at F17; Pbars injected from A1 line at E48 36 bunches of proton and pbars circulate in same beam pipe, but separated by electrostatic separators 3 trains of 1 bunches with 396 ns separation (see the next page) low β (small beam size) intersection points (CDF and D0) 8 RF cavities (near F0) to keep beam in bucket, acceleration 1113 RF buckets (53.1 MHz 18.8 ns bucket length) Hadron Collisions at the Tevatron and the LHC 4

13 Proton Bunch Positions 3 trains of 1 bunches with 396 ns separation P1 P13 P4 P5 P36 P1 Hadron Collisions at the Tevatron and the LHC 5 Protons and Pbars at HEP A4~P13 Proton bunches P1-P1 P13-P4 P5-P36 CDF A5-A36 A1-A1 A13-A4 D0 A13-A4 A5-A36 A1-A1 P5~P36 Hadron Collisions at the Tevatron and the LHC 6

14 Proton-Pbar Pbar Collision Point Hadron Collisions at the Tevatron and the LHC 7 First Collisions at the Tevatron Run 493 Event 11 Run 493 Event 15 October 13, 1985 Hadron Collisions at the Tevatron and the LHC 8

15 Large Hadron Collider ~7km circumference 13 bends Main bends are 14.3 meters long The strength of each magnet is 8.33 Tesla Huge synchrotron radiation loss. Highlights

16 Accelerated charges produce radiation. r r r e n (n β) & E a = c R ret r c r r c r S = E B = E a 4π 4π dp c r e = RE a = dω 4π 4πc e P = v&r 3 3 c P γ q = 6π ε ο m c 3 Synchrotron Radiation r dp dt r n r r n (n β) & e = 4πc Useful equations for ideal conditions in SI 3 v&r sin Θ P γ v& q m qvb = γm Above we integrated over the angle Θ, and below switched to more familiar units SI From here were can get 4 U B if r 1 de dp << c dτ dτ Go to, for example, Jackson s Classical Electrodynamics book, find more convenient expression in terms of v, ρ, γ Hadron Collisions at the Tevatron and the LHC 31

Relativistic kinematics basic energy, mass and momentum units, Lorents force, track bending, sagitta. First accelerator: cathode ray tube

Accelerators Relativistic kinematics basic energy, mass and momentum units, Lorents force, track bending, sagitta Basic static acceleration: First accelerator: cathode ray tube Cathode C consist of a filament,