FETS Pepperpot

Simon Jolly10th February 2010

The Pepperpot• Beam segmented by

intercepting screen with regular array of holes.

• Beamlets drift short distance before producing image on scintillator screen.

• Support block prevents beamlets from overlapping and provides cooling.

• CCD camera records image of light spots.

• Calculate emittance from spot distribution.

10/02/10 Simon Jolly, Imperial College 2

Incoming Beam

Intercepting screen

Support block

Scintillator screen

Beamlets

Fast CCD Camera

FETS Pepperpot Design

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Vacuum bellows

Camera

Moving rod

Shutter

Mounting flange

Pepperpot head

Bellows

Tungsten mesh

Beam profile head

Pepperpot and Slit-Slit Scanners

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Calibration System• Need to produce 4 light

spots on scintillator screen for calibration.

• Bring in 4 optical fibres through spare holes in copper mounting block.

• Fibre stops a little way short of scintillator screen, mounted in centre of 2mm x 13mm glass dowel.

• Glass dowel is frosted on scintillator screen end.

• Light from fibre produces 1mm spot on frosted end of glass dowel ie. at scintillator screen.

• Spots are imaged for calibration.

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Scintillator screen

Copper mounting block

Fast CCD Camera

To light source

Pepperpot Head

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FETS pepperpot uses tungsten intercepting screen with 50 micron holes on 3 mm pitch, 10 mm drift and quartz scintillator.

Pepperpot Head: Mounting Holes

10/02/10 Simon Jolly, Imperial College 7

FETS pepperpot uses tungsten intercepting screen with 50 micron holes on 3 mm pitch, 10 mm drift and quartz scintillator.Tungsten screen and copper mounting blocks are aligned with 4 2mm x 13mm metal dowels.

Pepperpot Head: Calibration Holes

10/02/10 Simon Jolly, Imperial College 8

FETS pepperpot uses tungsten intercepting screen with 50 micron holes on 3 mm pitch, 10 mm drift and quartz scintillator.Tungsten screen and copper mounting blocks are aligned with 4 2mm x 13mm metal dowels.

4 spare 2mm dowel holes to be used for fibre optic calibration

Fibres come in from back side of head.

Pepperpot Support & Main Flange

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The linear shift mechanism (LSML) from UHVDesign mounted to the main flange.

Adjustable camera mount.

Cooled feed through rod.

KF-40 vacuum flanges used for feedthroughs

Pepperpot Mounted to Vacuum Tank

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KF-40 flange to be used for fibre optic feedthrough.