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Title: Nitrogen incorporated ultrananocrystalline diamond based field emitter array for a flat-panel x-ray source

A field emission based flat-panel transmission x-ray source is being developed as an alternative for medical and industrial imaging. A field emitter array (FEA) prototype based on nitrogen incorporated ultrananocrystalline diamond film has been fabricated to be used as the electron source of this flat panel x-ray source. The FEA prototype was developed using conventional microfabrication techniques. The field emission characteristics of the FEA prototype were evaluated. Results indicated that emission current densities of the order of 6 mA/cm{sup 2} could be obtained at electric fields as low as 10 V/μm to 20 V/μm. During the prototype microfabrication process, issues such as delamination of the extraction gate and poor etching of the SiO{sub 2} insulating layer located between the emitters and the extraction layer were encountered. Consequently, alternative FEA designs were investigated. Experimental and simulation data from the first FEA prototype were compared and the results were used to evaluate the performance of alternative single and double gate designs that would yield better field emission characteristics compared to the first FEA prototype. The best simulation results are obtained for the double gate FEA design, when the diameter of the collimator gate is around 2.6 times the diameter of the extraction gate.
Authors:
; ; ;  [1] ; ; ; ;  [2]
  1. Nuclear Engineering, Missouri University of Science and Technology, 220 Fulton Hall, Rolla, Missouri 65401 (United States)
  2. Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
Publication Date:
OSTI Identifier:
22273662
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; 07 ISOTOPES AND RADIATION SOURCES; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; CRYSTALS; CURRENT DENSITY; DESIGN; DIAMONDS; ELECTRIC FIELDS; ELECTRON SOURCES; FIELD EMISSION; LAYERS; NANOSTRUCTURES; NITROGEN; SILICON OXIDES; THIN FILMS; X-RAY SOURCES