A Biased Anode to Suppress Ion Back- Bombardment in a DC High Voltage Photoelectron Gun
نویسندگان
چکیده
Ion back-bombardment is the dominant mechanism that limits the operating lifetime of DC high voltage GaAs photoelectron guns. In this work, an electrically isolated anode electrode was used to distinguish the QE damage contributions of ions produced within the cathode/anode gap and those produced downstream of the anode. This new anode design provides a means to suppress QE decay due to ionized gas in the beam line.
منابع مشابه
Design of a Dc/rf Photoelectron Gun*
An integrated dc/rf photoelectron gun produces a lowemittance beam by first rapidly accelerating electrons at a high gradient during a short (~ 1 ns), high-voltage pulse, and then injecting the electrons into an rf cavity for subsequent acceleration. Simulations show that significant improvement of the emittance appears when a high field (~ 0.5 1 GV/m) is applied to the cathode surface. An ad...
متن کاملLoad-locked dc high voltage GaAs photogun with an inverted-geometry ceramic insulator
"Load-locked dc high voltage GaAs photogun with an inverted-geometry ceramic insulator" (2010). A new dc high voltage spin-polarized photoelectron gun has been constructed that employs a compact inverted-geometry ceramic insulator. Photogun performance at 100 kV bias voltage is summarized.
متن کاملDramatic Reduction of Dc Field Emission from Large Area Electrodes by Plasma-source Ion Implantation*
Field emission is one of the principal phenomena limiting the operating voltage of practical electron guns. There is interest in developing photoemission cathode based DC electron guns employing cathode field strengths and cathode-anode voltages well above the present stateof-the-art. Such electron sources could provide high brightness, high average current beams for energy recovered supercondu...
متن کاملStudies of Linear and Nonlinear Photoelectric Emission for Advanced Accelerator Applications
Various electron emission properties of accelerator photocathodes were studied using short pulse lasers. The quantum efficiencies (QE’s) of copper and magnesium were compared before and after above-damage threshold laser cleaning. Changes in the emission properties of copper photocathodes used in the UCLA RF photoinjector gun were observed by mapping the QE's of the cathode surfaces. The electr...
متن کاملHigh energy electron fluxes in dc-augmented capacitively coupled plasmas I. Fundamental characteristics
Power deposition from electrons in capacitively coupled plasmas CCPs has components from stochastic heating, Joule heating, and from the acceleration of secondary electrons through sheaths produced by ion, electron, or photon bombardment of electrodes. The sheath accelerated electrons can produce high energy beams which, in addition to producing excitation and ionization in the gas can penetrat...
متن کامل