We report on the propagation of electron beams generated by a niobium photocathode illuminated by different wavelength excimer lasers. The cathode used was a polycrystalline disc. Its work function was 4.3 eV while the laser photon energy was 4.02 eV for the XeCl laser and 5.6 eV for the KrCl laser. The anode–cathode distance was variable as well as the saturation output current. At low accelerating voltage the beam was space charge dominated but its peak value was not limited by the Child–Langmuir calculated value. A fast shunt resistance allowed to record the electron beam generated with a fast rise time. The maximum output current was reached with the KrCl laser which provided an electron bunch containing 980 mA and 9 nC.
Electron beam propagation in a space-charge regime
MARTINA, Luigi;NASSISI, Vincenzo;PEDONE, Alessandro
2002-01-01
Abstract
We report on the propagation of electron beams generated by a niobium photocathode illuminated by different wavelength excimer lasers. The cathode used was a polycrystalline disc. Its work function was 4.3 eV while the laser photon energy was 4.02 eV for the XeCl laser and 5.6 eV for the KrCl laser. The anode–cathode distance was variable as well as the saturation output current. At low accelerating voltage the beam was space charge dominated but its peak value was not limited by the Child–Langmuir calculated value. A fast shunt resistance allowed to record the electron beam generated with a fast rise time. The maximum output current was reached with the KrCl laser which provided an electron bunch containing 980 mA and 9 nC.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
