title: Laser-photofield emission from needle cathodes for low-emittance electron beams.
abstract: Illumination of a ZrC needle with short laser pulses (16 ps, 266 nm) while high voltage pulses (-60 kV, 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 50 microm leading to a theoretical intrinsic emittance below 0.05 mm mrad.
authors: Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors: R
authors: R
authors: Ganter
authors: R
authors: R
authors: Bakker
authors: C
authors: C
authors: Gough
authors: S C
authors: SC
authors: Leemann
authors: M
authors: M
authors: Paraliev
authors: M
authors: M
authors: Pedrozzi
authors: F
authors: F
authors: Le Pimpec
authors: V
authors: V
authors: Schlott
authors: L
authors: L
authors: Rivkin
authors: A
authors: A
authors: Wrulich