In 1925 invented a microphone based on
thermionic currents (currents emitted by heated bodies) and a light projector using the interference phenomenon. Founded in the same year the first Electricity and Magnetism Laboratory, as well as the first Chair of Electricity and Magnetism in the Department of Mathematics and Physics at the
University of Bucharest.
The first prototype of a precursor to the magnetron power amplifier He built in 1934–1935 a precursor to the high-power, multi-
cavity magnetron that was built subsequently, in 1937–1940, by the British physicist,
Sir John Turton Randall, FRSE together with a team of British coworkers for the British and American, military
radar installations in WWII. At the same time, the
Telefunken Company of Berlin was 'searching' for such a device but has apparently met with much less success than the British inventors or Th. V. Ionescu. (However, the
split anode magnetron had first been developed in 1921 by Dr. A.E.Hull at
General Electric Company in USA; also in 1921, Ernst Haban, who was working in Germany, developed a similar device that worked on a 3 cm wavelength. A strong competitor of the former inventors was also Dr. H.E.Hollman who registered many patents between 1925 and 1935 that documented devices related to magnetron development).
Patents In 1936, he obtained a patent for the
3D imaging in cinema and television. In 1946, together with physicist V. Mihu invented and built a
maser-type device.
Discoveries He worked in the early 1960s in the Laboratory of the Bucharest Institute of Plasma Physics together with his childhood friend, Octav Gheorghiu, whom he greatly respected for his exceptional human qualities. They studied systematically the resonant frequencies of molecular oxygen and hydrogen ions. Then, they published their most important experimental results in a series of articles in
C. R. Acad. Sci. Paris.(pp. 245, 898, 957, 246, pp. 2250, 3598, 1958, 250, 2182 p. 1960, 252, p. 870, 1961) and
Rev Roum. Phys. In the early 1970s, together with physicists Radu Pârvan and
J. C. Băianu - one of his Ph.D. research assistants in plasma physics in magnetic fields in the Electricity Department of the Faculty of Physics, Bucharest – Ionescu completed experiments on controlled magnetic resonance oscillations in ultra-hot plasmas. These seminal experiments involved the coupling of ionic and electronic oscillations in ultra-hot plasma, utilizing quantum-amplified stimulation processes in the presence of longitudinal magnetic fields. This opened up novel possibilities for achieving hot nuclear fusion in the future (Achieving nuclear fusion in high pressure hot plasma). The first report of these research results was presented at the French Academy of Science in Paris by Louis Néel, member of the Academy and Nobel Prize in Physics for Magnetism. Additional results were then published in the same year in the internationally renowned magazine
C. R. Acad. Sci. Paris. His successor as Head of Department in 1970 was Florin Ciorăscu, "imported" from the IFA, (who died in 1977 during the
major earthquake in Bucharest). ==Notes==