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arXiv · 1210.1236

Synchroscan streak camera imaging at a 15-MeV photoinjector with emittance exchange

A. H. Lumpkin·J. Ruan·R. Thurman-Keup
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Abstract

At the Fermilab A0 photoinjector facility, bunch-length measurements of the laser micropulse and the e-beam micropulse have been done in the past with a fast single-sweep module of the Hamamatsu C5680 streak camera with an intrinsic shot-to-shot trigger jitter of 10-20ps. We have upgraded the camera system with the synchroscan module tuned to 81.25MHz to provide synchronous summing capability with less than 1.5ps FWHM trigger jitter and a phase-locked delay box to provide phase stability of ~1ps over 10s of minutes. These steps allowed us to measure both the UV laser pulse train at 263nm and the e-beam via optical transition radiation (OTR). Due to the low electron beam energies and OTR signals, we typically summed over 50 micropulses with 0.25-1nC per micropulse. The phase-locked delay box allowed us to assess chromatic temporal effects and instigated another upgrade to an all-mirror input optics barrel. In addition, we added a slow sweep horizontal deflection plug-in unit to provide dual-sweep capability for the streak camera. We report on a series of measurements made during the commissioning of these upgrades including bunch-length and phase effects using the emittance exchange beamline and simultaneous imaging of a UV drive laser component, OTR, and the 800nm diagnostics laser.

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A. H. Lumpkin, J. Ruan, R. Thurman-Keup. 2012-10-03. Synchroscan streak camera imaging at a 15-MeV photoinjector with emittance exchange. https://doi.org/10.1016/j.nima.2012.05.068

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