11th RAL MasterclassIntroduction
11th RAL MasterclassIntroduction
Glenn PatrickRutherford Appleton Laboratory
http://hepwww.rl.ac.uk/pust/masterclass.htm
12 – 14 March 2008
2
Probing Matterp
h
Shorter wavelengths means higher energies.
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Higher Energies Reveal Deeper Structure
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E = mc2
E = mc2
E kTE kT
Particle Physics
Astronomy
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Cosmic Particles
Interactions in the atmosphereLow flux of particles
Difficult to identify/control
Accelerators!
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Force on charged particle is given by the Lorentz Force
BvqEqF
Charged Particle Beams
Electric FieldAcceleration
Magnetic FieldBending
Cathode(-) Anode(+)
e-
p+
e+ e-
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John Cockroft & Ernest Walton Voltage Multiplier – Cavendish Laboratory, 1932.
1897 – J.J. Thomson
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Cockroft/Walton
Pre-Injectors
750kV FermiLab
665 kV ISIS, RAL(replaced 2004)
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Fermilab (400 MeV)
+ - ++ + --Alternating RF voltage. Each step gives a small energy increase to the particle.
LINEAR ACCELERATORS
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2 mile Linear Accelerator, SLAC, Stanford
Wor
ld’s
long
est bu
ildin
g
World
’s st
raig
htest
build
ing
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CyclotronFirst circular particle accelerator built by Ernest O. Lawrence & Stanley Livingston at Berkeley in 1930.Energy = 80 keV, Diameter = 13cm
Circular Accelerators
13 cm
12In a Collider, bunches of particles/antiparticlescirculate in opposite directions.
PRINCIPAL COMPONENTS OF A SYNCHROTRON
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Super Proton Synchrotron CERN, Geneva
(6km circumference)
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Radio Frequency Cavities
Large Electron Positron Collider (LEP)
1989-2000 27km circumference 3,000 bending magnets 800 focussing magnets 11,000 revolutions/sec
LEP (CERN)
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Electromagnetic waves
accelerate particles in the same way that waves propel
surfers. Timing is vital!
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Sextupole (LEP)Correction of chromatic spread.
Focussing MagnetsQuadrupole (LEP)
Strong FocussingBeam alternatelyfocussed in horizand vert planes.
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Tevatron, FermiLab, Chicago
Collides protons and anti-protonsEnergy = 1 TeV (1000 GeV)
4 mile circumference
Main injector
Tevatron
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velocity(proton)= 0.999999991c
Large Hadron Collider (LHC)
Thisafternoon
Thisafternoon
7 TeV protons colliding with 7 TeV protons. 27km circumference. Starts operation later in 2008.
8,000 cryomagnets. 40,000 tons of metal cooled to -271°C.2835x2835 bunches, 1011 protons/bunch, Crossing rate 40MHz.
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Synchrotron RadiationDiamond Light Source
Started operation: Feb 2007. Uses synchrotron radiation for studies at molecular/atomic level.
e
4
0
1
m
E
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You are here
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International Linear Collider
~31 km
250 GeV electrons colliding with 250 GeV positrons
8 February 2007 Reference Design Report2010 Engineering Design2019 – 2025? Operation??
The Next Generation?
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Masterclass Programme
09:30 Arrival, Coffee and Doughnuts (R22)
10:00 Welcome Elizabeth Clarke10:05 Introduction Dr. Glenn Patrick10:20 Fundamentals of Particle Physics Dr. Stefania Ricciardi11:00 Introducing ISIS and Diamond Dr. Martyn Bull
11:35 Group A: Visit to ISIS or Diamond Group B: Computer Study Drs. Tricoli & Wielers
12:30 Buffet Lunch (R18)
13:30 The Large Hadron Collider Dr. Monica Wielers
14:15 Group B: Visit to ISIS or DiamondGroup A: Computer Study Drs. Tricoli & Wielers
15:15 TeaOpportunity for video link with CERN
15:30 Applications of Particle Accelerators Dr. Rob Edgecock
16:00 Question and Answer Session
16:15 End
Material can be found at: http://hepwww.rl.ac.uk/pust/masterclass.htm