Demonstration of Cathode Emittance Dominated High Bunch Charge Beams in a DC gun-based Photoinjector

Abstract

We present the results of transverse emittance and longitudinal current profile measurements of high bunch charge (greater than or equal to 100 pC) beams produced in the DC gun-based Cornell Energy Recovery Linac Photoinjector. In particular, we show that the cathode thermal and core beam emittances dominate the final 95% and core emittance measured at 9-9.5 MeV. Additionally, we demonstrate excellent agreement between optimized 3D space charge simulations and measurement, and show that the quality of the transverse laser distribution limits the optimal simulated and measured emittances. These results, previously thought achievable only with RF guns, demonstrate that DC gun based photoinjectors are capable of delivering beams with sufficient single bunch charge and beam quality suitable for many current and next generation accelerator projects such as Energy Recovery Linacs (ERLs) and Free Electron Lasers (FELs).

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• New electron source concept for single-shot sub-100 fs electron diffraction in the 100 keV range
• Observation of Parity Nonconservation in Moller Scattering
• Thermal emittance measurements of a cesium potassium antimonide photocathode
• Synchrotron radiation representation in phase space
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• Single shot cathode transverse momentum imaging in high brightness photoinjectors
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