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Title: TiN coated aluminum electrodes for DC high voltage electron guns

Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloy (Ti-6Al-4V). Following gas conditioning, each TiN-coated aluminum electrode reached −225 kV bias voltage while generating less than 100 pA of field emission (<10 pA) using a 40 mm cathode/anode gap, corresponding to field strength of 13.7 MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ∼22.5 MV/m with field emission less than 100 pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coatingmore » (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.« less
Authors:
;  [1] ;  [2] ; ;  [3]
  1. Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, Virginia 23529 and The Applied Research Center, Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)
  2. Department of Physics, Loyola Marymount University, Los Angeles, California 90045 (United States)
  3. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)
Publication Date:
OSTI Identifier:
22392187
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 33; Journal Issue: 3; Other Information: (c) 2015 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM; ANODES; CATHODES; ELECTRIC POTENTIAL; HARDNESS; NIOBIUM; STAINLESS STEELS; TITANIUM; TITANIUM ALLOYS; TITANIUM NITRIDES