VISA - Talks at the April 2001 Meeting at Brookhaven

A meeting of the VISA collaboration took place at the Brookhaven National Laboratory (BNL) to review the recent results of the VISA experiment.At the core of the meeting were technical presentations discussing the various parts of the ATF VISA system. The main results of the experiment are intensity as well as spectral measurements ( of the fundamental as well as the second and third harmonic ) taken at ports along the undulator From the intensity vs. z measurements follows a gain length of 18.5 cm associated with gain levels above 10⁷. There is clear evidence that staturation occurs at the end of the undulator. The radiation spectra show less structure than expected, which could be due to the energy chirp of the electron beam or could be an indication that the electron bunch is shorter than expected. An additional result of the experiment, i.e., the measurements of slice emittance, requires further determination of the actual electron bunch length at the undulator. The slice emittance can be calculated from the gain length, the bunch length, the charge and the slice energy spread. For bunch lengths as measured in the linac the corresponding slice emittances would be significantly short er than the measured projected emittances. J. Rosenzweig pointed out that nonlinear bunch compression in the linac-to-undulator beamline could very well be strong enough to shorten the bunch by more than a factor of two. Direct length measurements of the IR pulse after the undulator to determine the actual length of the pulses used were suggested

Agenda

9:00-9:10 AM	Welcome	S. Krinsky and R. Osgood
9:10-9:30 AM	Status of the VISA Experiment	A. Tremaine
9:30-9:45 AM	ATF Photocathode-RF-Gun Laser System	M. Babzien
9:45-10:15 AM	VISA Experienc e with the ATF Photoinjector Based Linac	X.J. Wang
10:15-10:30 AM	Coffee Break
10:30-11:00 AM	Trajectory and Optics Control of the Electron Beam for VISA	H.-D. Nuhn
11:00-11:30 AM	VISA Saturation Measurements	Alex Murokh
11:40-12:00 AM	ATF Longitudinal Beam Dynamics	J. Rosenzweig
11:30-11:40 AM	Comments on ATF	I. Ben Zvi

Talks

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Summary

Agenda

Talks