Experiments on EMMA Requiring

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16 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

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Experiments on EMMA Requiring
Minimal or No Modifications

J. Scott Berg

Brookhaven National Laboratory

18 March 2010

Outline of Existing Experiments


Find linear parameters vs. energy


Adjust lattice to desired configuration


Accelerate beam from 10 to 20
MeV


Scan longitudinal phase space


Scan longitudinal parameters (frequency/voltage)


Scan transverse phase space


Find variation in fixed
-
energy parameters


Study how acceleration changes with amplitude

2

Outline of Existing Experiments


Introduce errors, look at effects


Set up additional lattice configurations


Different tune range


Effects related to resonances


Look for variation in emittance growth and beam loss


Verify expected effects on longitudinal dynamics


Different location of time of flight minimum


Look at variation in longitudinal dynamics


Expect similar behavior in transverse: verify

3

Single Resonance Crossing


Acceleration over a limited range


Cross an individual resonance slowly


Use a low voltage, vary to change rate


Reduced range serpentine acceleration


Only works near
ToF

minimum


Oscillation around stable fixed point


Study fixed energy behavior near resonance


Diagnostic need: accurate emittance


4

Measurement of Momentum Spread


Chromaticity: beam signal
decays


Signal shape depends on
momentum distribution


Reconstruct distribution


Take this data anyhow


Compare to momentum
distribution measured
elsewhere

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More Discrete Acceleration


Machida: orbit
distortion from fewer
cavities


Turn some cavities
off and reproduce

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Space Charge/Beam Loading


Basic design is to look at single
-
particle
dynamics


Could look at weak current
-
dependent effects


Beam loading: just push current up


See effect on acceleration, try to correct for it


Space charge: make beam small if possible


Measure incoherent tune spread


Look at effect on acceleration

7

Diagnostics for Experiments


We proposed many diagnostics, but


Couldn’t afford all of them


Identify diagnostics needs/desires for
experiments


Helps us to


Justify request


Prioritize what to ask for/buy

8

Final Remarks


Thanks to Shinji,
Eberhard
, Rob for
suggestions


Hopefully I didn’t miss anyone


Continue making suggestions as you get ideas

9