The concept of an electron-optical system with field emitter for a spectroscopic gyrotron

We describe multitip field emitters with protective coatings, which were developed in Peter the Great St. Petersburg Polytechnic University. The coatings ensure long-term operation of the emitters under high currents and technical vacuum. Innovative multi-layer emitters composed of contacting nanolayers of materials with different work functions are presented as well. The possibility by using the developed emitters in high-voltage electronic devices is demonstrated.

Innovative Field Emitters for High-Voltage Electronic Devices

Issues pertaining to the effective solution of problems related to the creation of durable low-voltage field emission cathodes with developed working surface and high density of emission current are considered. Results of practical implementation of the concept of multielectrode field emission planar nanostructures based on diamond-like carbon are presented. High average current density (0.1–0.3 A cm–2) is ensured by the formation of a controlled zone of electrostatic field localization at the planar-edge structure. The working life of cathode samples reaches 700–3000 h due to several positive factors, such as the stabilizing properties of a diamond-like carbon film, protection of the emitter from ion bombardment, use of a system of ballast resistors, and low-voltage operation of submicron interelectrode gaps.

A planar diamond-like carbon nanostructure for a low-voltage field emission cathode with a developed surface

Perspective low-macroscopic field (LMF) emission prototype cathodes based on fullerene C60—doped porous silicon were realized via a two-stage technique comprising the electrochemical etching process of a monocrystalline silicon wafer and functionalization of the acquired porous silicon (PS) matrix with silver-doped fullerene-based carbon structures. The resulting LMF cathode prototypes were studied with SEM and EDS techniques. The formation of an amorphous silver-doped C60-based layer consisting of nanosized aggregates on the matrix surface was established. The emission characteristics of the prototypes were analyzed, crucial parameters including threshold field strength values, emission current density, and effective potential barrier height for electrons were considered. A novel LMF emission model is suggested. It was established that the emitter prototypes realized during this study are on par with or superior to modern and promising field cathodes.

Advances in Novel Low-Macroscopic Field Emission Electrode Design Based on Fullerene-Doped Porous Silicon

A technology of creation of annular silicon field emitters with bilayer metal–fullerene coating has been developed and their performance has been studied. It has been shown that annular emitters with a surface area of about 0.3 cm2 provide a current up to 100–110 mA and stably operate under conditions of technical vacuum (~10–7 Torr).

Annular Multi-Tip Field Emitters with Metal–Fullerene Protective Coatings

We investigate the operation of multitip silicon field emitters with new-type bilayer metal—fullerene protective coatings in technical vacuum. The experiments indicate that such cathodes ensures emission current densities averaged over the cathode surface of about 0.5 A/cm2 and can be used in high-voltage devices including microwave electronic instruments as well as portable X-ray sources.

Multitip semiconductor field emitters with new-type bilayer protecting coatings

We investigate multitip field emitters prepared by electroerosion treatment of the surface of molybdenum samples. Their characteristics are determined for operation with a protecting activated fullerene coating. Our experiments indicate that such cathodes are promising for high-voltage electron devices operating in technical vacuum.

Simple-to-prepare multipoint field emitter

The miniature cold field emitters are very attractive for utilization in low-power gyrotrons operating in range of short millimeter and terahertz waves. But such emitters are usually nondurable when exploiting in technical vacuum. Multi-tip field emitters with protective coatings developed and investigated by the authors are promising for use in short-wave gyrotrons operating in a technical vacuum.

http://ieeexplore.ieee.org/iel7/6927585/6955975/06956505.pdf

Multi-tip field emitters for electron devices operating in technical vacuum

http://ieeexplore.ieee.org/iel7/6881323/6891922/06892083.pdf

E. P. Taradaev

Papers

Multitip semiconductor field emitters with new-type bilayer protecting coatings

Simple-to-prepare multipoint field emitter

Multi-tip field emitters for electron devices operating in technical vacuum

Multitip field emitters for electron devices operating in technical vacuum