High-frequency current modulation in a diode with a plasma cathode

The authors present a study of the modulation at frequencies of hundreds of MHz of an electron beam (I/sub e//spl les/30 A, E/sub e//spl les/40 keV, /spl tau//sub p//spl les/35 /spl mu/s) produced by a plasma cathode. The plasma was prepared by a noncomplete discharge that was ignited by a driving pulse applied between the front strips and a solid rear electrode of a ferroelectric sample [BaTiO/sub 3/ or Pb(Zr,Ti)O/sub 3/]. Investigation of the plasma and the beam modulation properties and their dependence on the experimental parameters is presented. The results are discussed within the framework of electrons oscillating in the potential well created by the positively charged plasma having feedback coupling with the input cable.