Abstract
Illumination of a ZrC needle with short laser pulses (16 ps, 266 nm) while high voltage pulses (, 2 ns, 30 Hz) are applied, produces photo-field emitted electron bunches. The electric field is high and varies rapidly over the needle surface so that quantum efficiency (QE) near the apex can be much higher than for a flat photocathode due to the Schottky effect. Up to 150 pC (2.9 A peak current) have been extracted by photo-field emission from a ZrC needle. The effective emitting area has an estimated radius below leading to a theoretical intrinsic emittance below 0.05 mm mrad.
- Received 24 August 2007
DOI:https://doi.org/10.1103/PhysRevLett.100.064801
©2008 American Physical Society