Ferroelectric Cathode Measurements
Abstract
We have recently initiated an investigation of electron emission from ferroelectric cathodes. our experimental apparatus consisted of an electron diode and a 250 kV, 12 ohm, 70 ns pulsed high voltage power source. A planar triode modulator driven by a synthesized waveform generator initiates the polarization inversion and allows inversion pulse tailoring. Our initial measurements indicate that emission current densities above the Child-Langmuir Space Charge Limit, JCL, are possible. We explain this effect to be based on a non-zero initial energy of the emitted electrons. We also determined that this effect is strongly coupled to relative timing between the inversion pulse and application of the main anode-cathode pulse. We also have initiated brightness measurements of the emitted beam and estimate a preliminary lower bound to be on the order of 10 to the 9th power A/m2-rad2 for currents close to JCL and factor of two less at currents over 4JCL. We describe our apparatus and preliminary measurements.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1993
- Accession Number
- ADA638908
Entities
People
- C. L. Holmes
- D. O. Trimble
- D. Prosnitz
- E. J. Lauer
- G. A. Westenskow
- G. J. Caporaso
- S. Sampayan
Organizations
- Lawrence Livermore National Laboratory