Fermilab, Batavia, Illinois
OTR interferometry (OTRI) is an attractive diagnostic for investigation of relativistic electron beam parameters. The diagnostic is currently under development at the A0 Photoinjector. This diagnostic is applicable for NML accelerator test facility that will be built at Fermilab. The experimental setups of the OTR interferometers for the Photoinjector prototype are described in the report. Results of simulations and measurements are presented and discussed.
UCLA, Los Angeles, California
Fermilab, Batavia, Illinois
Rochester University, Rochester, New York
Northern Illinois University, DeKalb, Illinois
Focusing of a 15 MeV, 19 nC electron bunch by an underdense plasma lens operated just beyond the threshold of the underdense condition has been demonstrated in experiments at the Fermilab NICADD Photoinjector Laboratory (FNPL). The strong 1.9 cm focal-length plasma-lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. Analysis of the beam-envelope evolution observed near the beam waist shows that the spherical aberrations of this underdense lens are lower than those of an overdense plasma lens, as predicted by theory. Correlations between the beam charge and the properties of the beam focus corroborate this conclusion. Time resolved measurements of the focused electron bunch are also reported and all results are compared to simulations.
Fermilab, Batavia, Illinois
Recently we have measured the transverse emittance using both multi-screen as well as muli-slit methods for a range of electron beam intensities from 1 nC to 4 nC at A0 Photoinjector facility at Fermilab. The data have been taken with un-stacked 2.5 ps laser pulse. In this paper we report on these measurements and compare the results with the predictions from beam dynamics calculations using ASTRA and General Particle Tracer including 3D space charge effects.