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.

3

Higher Energies Reveal Deeper Structure

4

E = mc2

E = mc2

E kTE kT

Particle Physics

Astronomy

5

Cosmic Particles

Interactions in the atmosphereLow flux of particles

Difficult to identify/control

Accelerators!

6

Force on charged particle is given by the Lorentz Force

BvqEqF

Charged Particle Beams

Electric FieldAcceleration

Magnetic FieldBending

Cathode(-) Anode(+)

e-

p+

e+ e-

7

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)

9

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

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 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