Glenn Patrick Rutherford Appleton Laboratory heprl.ac.uk/pust/masterclass.htm

Glenn Patrick Rutherford Appleton Laboratory

http://hepwww.rl.ac.uk/pust/masterclass.htm

INTRODUCTIONA Very Brief Guide

to Accelerators

RAL Masterclasses 2009

2

Microscopes & Telescopes ~ 400 Years Ago

Galileo’s telescope, ~1609, FlorenceMagnification ~30

Compound microscope

~1670, Glasgow

Magnification ~30

Siderius Nuncius,Galileo Galilei, 1610

MicrographiaRobert Hooke, 1665

3

Small Scales and Large Scales - Today

Hubble Ultra Deep Field (2004)

Large Hadron Collider (2009)

44

E = mc2E = mc2

E kTE kT

Particle Physics

Astronomy

5

Probing Matter

p

h

Higher energies means shorter wavelengths.

6

Cosmic Particles

Accelerators!

Interactions in the atmosphereLow flux of particlesDifficult to identify/control

77

Force on charged particle is given by the Lorentz Force

BvqEqF

Charged Particle Beams

Electric FieldAcceleration Magnetic Field

Bending

Cathode(-) Anode(+)

e-

p+

e+ e-

88

John Cockroft & Ernest Walton Voltage Multiplier

Cavendish Laboratory, 1932.

1897 – J.J. Thomson

99

Cockroft/WaltonPre-Injectors

750kV FermiLab

665 kV ISIS, RAL(replaced 2004)

1010

Fermilab (400 MeV)

+ - ++ + --Alternating RF voltage. Each step gives a small energy increase to the particle.

LINEAR ACCELERATORS

1111

2 mile Linear Accelerator, SLAC, Stanford

Wor

ld’s

long

est b

uild

ing

World’s stra

ightest build

ing

1212

Cyclotron

First circular particle accelerator built by Ernest O. Lawrence & Stanley

Livingston at Berkeley in 1930.

Energy = 80 keV, Diameter = 13cm

Circular Accelerators

13 cm

13

Principal Components of a Synchrotron

In a Collider, bunches of particles/antiparticlescirculate in opposite directions.

1414

Super Proton Synchrotron CERN, Geneva

(6km circumference)

1515

Radio Frequency Cavities

Large Electron Positron Collider (LEP) 1989-2000

27 km circumference

3,000 bending magnets

800 focussing magnets

11,000 revolutions/sec

LEP (CERN)

1616

Electromagnetic waves accelerate particles in the same way that waves propel surfers.

Timing is vital!

1717

Sextupole (LEP)Correction of chromatic spread.

Focussing Magnets

Quadrupole (LEP)

Strong FocussingBeam alternatelyfocussed in horizand vert planes.

18

HERA – Electron Proton Collider (6.3 km)

p

920 GeV protons

27.5 GeV electrons/positrons

e

ɣproton

Hamburg, 1992-2007Hamburg, 1992-2007

1919

Tevatron, FermiLab, Chicago

Collides protons and anti-protonsEnergy = 1 TeV (1000 GeV)

4 mile circumference

Main injector

Tevatron

2020

Synchrotron RadiationDiamond Light Source

Started operation Feb 2007. Uses synchrotron radiation for studies at

molecular/atomic level.

e

4

0

1

m

E

RE

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 – 2012 Technical Design Phase? Construction/Operation

The Next Generation?

22

Masterclass Programme09:30 Arrival, Coffee and Doughnuts (R18)

10:00 Welcome Caroline Callard10:05 A Very Brief Guide to Accelerators Dr. Glenn Patrick

10:20 Fundamentals of Particle Physics Dr. Stefania Ricciardi11:00 Introducing Diamond Dr. David Price11:15 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 DiamondGroup A: Computer Session Drs. Tricoli & Wielers

15:15 Tea

15:30 Applications of Particle Accelerators Dr. Rob Edgecock

16:00 Question and Answer Session16:15+ End

Material can be found at: http://hepwww.rl.ac.uk/pust/masterclass.htm

23

Energy Units!

1 eV = 1 electron VoltEnergy to ionise hydrogen = 13.6 eV

1 keV(kilo) = 1,000 eV = 103 eVMedical X-ray ~ 200 keV

1 MeV(Mega) = 1,000,000 eV = 106 eVAlpha particle decay of uranium 4.2 MeV

1 GeV(Giga) = 1,000,000,000 eV = 109 eVLEP collider beam (1989-200) = 45 GeV

1 TeV(Tera) = 1,000,000,000,000 eV = 1012 eVHighest energy accelerator in world = 1 TeV (Tevatron)

Electron Volt – Energy gained by an electron when accelerated in an electric field through a potential difference of 1 volt.

Highest energiesfound in cosmic rays (>1020 eV)