Series: Nuclear and Reactor Constants

since 1971

Русский (РФ)

ISSN 2414-1038 (online)

Authors & Affiliations

Yarygin V.I., Тulin S.M.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia

Yarygin V.I. – Chief Researcher, Dr. Sci. (Tech.), Professor. Contacts: 1, pl. Bondarenko, Obninsk, Kaluga region, Russia, 249033. Tel.: +7 (484) 399-88-29; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
TulinS.M. – Leading Engineer.


The article discusses the experimental results of a comprehensive research of polycrystalline niobium electrodes in a laboratory thermoemission thermal-to-electrical converter (TIC), modified by large-dose implantation of oxygen ions (fluence ~1018 ion/cm2). It was found by the methods of complex analysis that the activation annealing of the Nbimp reference sample/TIC electrodes causes changes in the crystallographic structure of the Nbimp electrodes with the formation on the emitter and collector surface of TICs (polycrystalline in the initial state) of a stable electronic system Nb-O of the type Nb6O suboxide with coarse-grained texture (110) with a grain size of 30–100 microns and a depth of oxygen up to 500–700 angstroms. The oxygen concentration on the surface of Nbimp electrodes is 4–5 at. %, which is an order of magnitude higher than the natural content of dissolved oxygen in the initial polycrystalline niobium. Thermionic measurements in a laboratory TIC established that the modification of Nbimp electrodes causes a significant improvement in the emission-adsorption characteristics of TIC with an Nbimp – Nbimp electrode pair.

Within the framework of a consistent physical model, the article examines the relationship between the properties of modified Nbimp electrodes with a highly efficient process of low-temperature thermionic conversion with an attractive barrier index efficiency (2±0.06 eV) and electrode efficiency ~11% (at an emitter temperature ~1600 K).

ion implantation, oxygen, emitter, collector, work function of electrons, crystallographic orientation of texture, element composition, current-voltage characteristic, thermionic converter

Article Text (PDF, in Russian)


UDC 621.311:621.039

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2022, issue 1, 1:8