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Diamond

RAL Particle Physics Masterclass12 March 2003

Glenn Patrick

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

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DIAMOND Synchrotron

Third Generation Light Source.To be built at RAL. Start of operation = 2006.Cost = £235M. Studies at molecular/atomic level.Ground-breaking - Wednesday 12th March!

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You are here

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Storage ring circumference = 560m

Control Room

Research Building

Shielding

Operations

Linac & Booster

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Energy = 3 GeV

Energy = 100 MeV

Beam Lifetime 10 hoursCurrent = 300 mA

1 MeV =1 x 106 eV

1 GeV =1 x 109 eV

1 TeV=1 x 1012 eV

Electron volt is energy given toan electron accelerated throughpotential difference of 1 volt.

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Force on charged particle is given by Lorentz Force

BvqEqF

Charged Particle Beams

Acceleration Bending

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RF CavitiesRadiofrequency (RF) Cavities Provide the acceleration energy.DIAMOND cavities will be based on superconducting niobium.

In the same way that waves propel surfers, EM waves accelerate particles.

Beam Pipe/Vacuum chamberBeams circulate in highly evacuated vacuum pipe to avoid loss of beam bycollision with air molecules

DIAMOND has a base pressure of ~10-10 torr.LEP vacuum was 10-12 torr – a world record!

ISR

LEP

LHC

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BRp 3.0 p=momentum in GeV/cB=magnetic field in TeslaR=bending radius in m

Bending Magnets

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Synchrotron Radiation

e Synchrotron RadiationEnergy loss per

revolution4

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RE

Choose electrons because they are thelightest charged particle

First observed in a circular accelerator in 1947(General Electric, New York).Seen naturally when charged particles spiral aroundmagnetic field lines in space.SRS at Daresbury (Cheshire) was world’s first dedicatedhigh-energy radiation source.

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Galaxy 3C 66B10,000 light year jet of plasma - emitting synchrotron radiationElectrons spiralling along magnetic field lines.

Hubble Space Telescope, 1991

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LEP Sextupole Correction of chromatic spread.

Focussing Magnets

LEP Quadrapole

Strong FocussingBeam alternatelyfocussed in horizand Vert planes.

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Insertion DevicesCan increase flux & brightnessof light from normal bending magnets many thousands of times by using insertion devices.Rows of small magnets

which “jiggle” the electron beam causing it to emit more radiation.Positioned on straight sections of the storage ring.

Wiggler

Undulator

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Probing Matter p

hShorter wavelengths

means higher energies.

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BeamlinesDiamond will be the best medium energy source in the world and is optimised to provide X-rays with energies from 100 eV up to 20 keV.

Initially 7 beamlines, but room for 30 or more

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Finally - Science!Protein

Cystallography

Foot & Mouth VirusMuscle Structure

PolypropylenediffractionEnzyme Structure Lithium niobate diffraction