HRRL OTR Test Mar 3rd 2011

Preparation

JAI Camera Setup

Target in:

Target out:

Target in after shielded:

Objectives

Determined if the steering magnets of the gun are connected to power supply

1. Physically check looking at wires.

2. Change currents on the steering magnet, and observe position of the beam spot. If changes then, connected.

Tune beam using Linac optics only

Chad will tune up the beam using steering elements which are within the HRRL Linac only.

Determined if the OTR target is centered on the beam line

With all beam line magnets off, observe the beam spot at the OTR target. If the beam is centered on the OTR target, then OTR target MAY be centered on the beam line.

Polarization test

Insert a polarizer film. Take several picture for different orientations without changing beam properties.

Angel is measured with respect to:

Polarizer Angel	Iamge
200 px	200 px

Determined if the quads are centered on the beam line

The power supplies for ALL quads should be off.

Turn on Quad closesst to HRRL

If the beam deflects, try to align quad so there is no deflection

Turn on Quad closest to OTR target

If the beam deflects, try to align quad so there is no deflection

Run

Field Emission Check

Peak Current (mA): 160

Rep Rate (Hz): 6

Pulse width (ns): 200

HV on, Filament on, RF on

HV off, Filament on, RF on

HV off, Filament on, RF off

HV on, Filament on, RF off

HV on, Filament on, RF on, Valve closed

HV off, Filament on, RF on, Valve closed

HV on, Filament on, RF off, Valve closed

HV off, Filament on, RF off, Valve closed

Conclusion

When the HV is off, there were not any electrons from filament. We still see back ground light. This due the the dark current, emitted from the cavity (field emission).

Estimation of How Much off

Rep Rate (Hz): 6

Pulse width (ns): 200

Take at least 3 images for each setting below.

The goal is to estimate how far things may be misaligned. Several assumption will be made.

Tuned for Max transmision to FC Just by steering Magnets

Peak Current (mA): 160

Using 1st Triplets

Peak Current (mA): 160

Using 2nd Triplets

Peak Current (mA): 160

Using Both Triplets

Peak Current (mA): 160

Tuned for Min Quad deflection

Find the spot that when we change quad currents, center of the beam spot does not change or change the lest.

Rep Rate (Hz): 6

Pulse width (ns): 200

Quqads off

Peak Current (mA): 35

Quads off:

1st quad of the 1st triplet on

1st quad of the 1st triplet power supply at (A): 2

1st quad of the 1st triplet power supply at (A): 4

1st quad of the 1st triplet power supply at (A): 6

1st quad of the 1st triplet power supply at (A): 8

1st quad of the 1st triplet power supply at (A): 10

2nd quad of the 1st triplet on

2nd quad of the 1st triplet power supply at (A): 2

2nd quad of the 1st triplet power supply at (A): 4

2nd quad of the 1st triplet power supply at (A): 6

2nd quad of the 1st triplet power supply at (A): 8

2nd quad of the 1st triplet power supply at (A): 10

Tune on center of Target

Rep Rate (Hz): 6 Pulse width (ns): 200 Peak Current (mA): 120

Tuned on center of the target:

Rf on, HV off (for back ground subtraction):

No beam, light is on:

OTR Check Polarization

Pulse width (FMHM): 200 ns

Peak Current: 160 mA

Camera focused at infinity.

No polarizer

Accelerator off, back ground

50 Hz Rep Rate

291 Hz Rep Rate

Polarization of the Polarizer Parallel to the Beam Line Direction

Polarization of the Polarizer Perpendicular to the Beam Line Direction

Time Slice Study of the OTR

Take pictures at different time slices from the trigger.

This means take a picture and then delay the trigger pulse to the camera relative to the RF. Perhaps the light has a time structure.

Rep Rate (Hz): 6

Pulse width (ns): 200

160 mA peak Current

Peak Current (mA): 160

105 mA peak Current

Peak Current (mA): 105

Far field

Now return the camera trigger back to the original location in time. Focus at infinity and try to observe polarization.

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