1. Rutherford Appleton Laboratory
RAL Masterclasses 2009
INTRODUCTION
A Very Brief Guide
to Accelerators
Glenn Patrick
Rutherford Appleton Laboratory

2. Microscopes & Telescopes ~ 400 Years Ago
Galileo’s telescope, ~1609, Florence
Magnification ~30
Compound microscope
~1670, Glasgow
Magnification ~30
Micrographia
Robert Hooke, 1665
Siderius Nuncius,
Galileo Galilei, 1610

3. Small Scales and Large Scales - Today
Large Hadron Collider (2009)
Hubble Ultra Deep
Field (2004)

4. Particle Physics
Astronomy
E = mc2
E  kT

5. Higher energies means shorter wavelengths.
Probing Matter
Higher energies means shorter wavelengths.

6. Cosmic Particles Accelerators! Interactions in the atmosphere
Low flux of particles
Difficult to identify/control
Accelerators!

7. Charged Particle Beams
Force on charged particle is given by the Lorentz Force e+ e-
Electric Field
Acceleration
Magnetic Field
Bending
Cathode(-)
Anode(+) p+ e-

8. John Cockroft & Ernest Walton Voltage Multiplier
1897 – J.J. Thomson
John Cockroft & Ernest Walton Voltage Multiplier
Cavendish Laboratory, 1932.

9. Cockroft/Walton Pre-Injectors 750kV FermiLab 665 kV ISIS, RAL
(replaced 2004)

10. + + + - + Fermilab (400 MeV) LINEAR ACCELERATORS -
Alternating RF voltage. Each step gives a small energy increase to the particle.

11. 2 mile Linear Accelerator, SLAC, Stanford
World’s straightest building
World’s longest building

12. Circular Accelerators
Cyclotron
First circular particle accelerator built by Ernest O. Lawrence & Stanley Livingston at Berkeley in 1930.
Energy = 80 keV, Diameter = 13cm
13 cm

13. Principal Components of a Synchrotron
In a Collider, bunches of particles/antiparticles
circulate in opposite directions.

14. Super Proton Synchrotron
CERN, Geneva
(6km circumference)

15. Radio Frequency Cavities
LEP (CERN)
Large Electron Positron Collider (LEP)
27 km circumference
3,000 bending magnets
800 focussing magnets
11,000 revolutions/sec

16. Electromagnetic waves accelerate particles in the same way that waves propel surfers.
Timing is vital!

17. Correction of chromatic spread.
Focussing Magnets
Quadrupole (LEP)
Strong Focussing
Beam alternately
focussed in horiz
and vert planes.
Sextupole (LEP)
Correction of chromatic spread.

18. HERA – Electron Proton Collider (6.3 km)
Hamburg,
920 GeV protons
27.5 GeV electrons/positrons p e ɣ
proton

19. Collides protons and anti-protons
Tevatron, FermiLab, Chicago
Tevatron
Main injector
Collides protons and anti-protons
Energy = 1 TeV (1000 GeV)
4 mile circumference

20. Synchrotron Radiation
Diamond Light Source  e
You are here
Started operation Feb Uses synchrotron radiation for studies at molecular/atomic level.

21. International Linear Collider
The Next Generation?
~31 km
250 GeV electrons colliding with 250 GeV positrons
8 February 2007 Reference Design Report
2010 – 2012 Technical Design Phase
? Construction/Operation

22. Masterclass Programme
09:30 Arrival, Coffee and Doughnuts (R18)
10:00 Welcome Caroline Callard
10:05 A Very Brief Guide to Accelerators Dr. Glenn Patrick
10:20 Fundamentals of Particle Physics Dr. Stefania Ricciardi
11:00 Introducing Diamond Dr. David Price
11:15 Introducing ISIS Dr. Martyn Bull
11:35 Group A: Visit to ISIS or Diamond
Group B: Computer Session Drs. Tricoli & Wielers
12:30 Buffet Lunch (R18)
13:30 The Large Hadron Collider Dr. Kristian Harder
14:15 Group B: Visit to ISIS or Diamond
Group A: Computer Session Drs. Tricoli & Wielers
15:15 Tea
15:30 Applications of Particle Accelerators Dr. Rob Edgecock
16:00 Question and Answer Session
16:15+ End
Material can be found at:

23. Energy Units!
Electron Volt – Energy gained by an electron when accelerated in an electric field through a potential difference of 1 volt.
1 eV = 1 electron Volt
Energy to ionise hydrogen = 13.6 eV
1 keV(kilo) = 1,000 eV = 103 eV
Medical X-ray ~ 200 keV
1 MeV(Mega) = 1,000,000 eV = 106 eV
Alpha particle decay of uranium 4.2 MeV
1 GeV(Giga) = 1,000,000,000 eV = 109 eV
LEP collider beam ( ) = 45 GeV
1 TeV(Tera) = 1,000,000,000,000 eV = 1012 eV
Highest energy accelerator in world = 1 TeV (Tevatron)
Highest energies
found in cosmic rays (>1020 eV)