Gennadii Andreevich Mesyats (on his 90th birthday)

On the threshold of spring 2026, academician Gennadii Andreevich Mesyats, a distinguished Russian physicist and organizer of science, turned 90.He is a recognized world leader in the field of electrophysics, pulsed energetics, and electronics.Gennadii Andreevich was born on February 29, 1936, in Kemerovo to a working-class family.He finished a high school with a silver medal in the city of Belovo, Kemerovo region.Academician G.A. Mesyats's scientific work began in 1957, when he was still a student at the Tomsk Polytechnic Institute (TPI).To study pulsed electric discharge in dielectrics, he designed a high-voltage nanosecond generator.In 1958, he defended his diploma thesis on this topic and entered the graduate course at TPI. G.A. Mesyats's first scientific publication was a 1959 paper in the journal Radiotekhnika i Elektronika (Radio Engineering and Electronics) on the study of strongly overvoltaged air gaps.Gennadii Andreevich published the results of his diploma thesis in the collective monograph ``High-voltage Test Equipment and Measurements'' (1960).In 1961, Gennadii Andreevich Mesyats defended his candidate thesis ``Development and research of high-voltage nanosecond pulsed devices with spark gaps.''These results had a significant impact on the development of technique of high-power nanosecond pulses.In 1962, G.A. Mesyats became a senior researcher and then head of the Electronics Laboratory at the Nuclear Physics Research Institute of TPI.He actively used highvoltage nanosecond pulse generators to study discharges in vacuum, liquids, gases, and solid dielectrics, to solve problems in quantum electronics, to design spark chambers, etc. Thanks to the work of Gennadii Andreevich and his colleagues, the technology of generating high-power nanosecond pulses became an independent scientific area.These works were summarized in his monograph ``The technology of forming high-voltage nanosecond pulses'' (the co-author G.A. Vorob'ev, 1963), and later in his doctoral thesis ``Research on generation of high-power nanosecond pulses,'' which he defended in 1966 at TPI.It should be noted that G.A. Mesyats's thesis contained three significant scientific fields.First, generation of high-power nanosecond pulses.Second, strong-current emission electronics and highpower electron beams based on the explosive electron emission (EEE) discovered by him.Third, gas electronics and pulsed gas lasers based on the high-pressure volume gas discharges (VGD) discovered by him.The discovery of EEE was the beginning of the area in strong-current electronics allowing exclusively high electron currents up to 10 7 A. In 1967, G.A. Mesyats's team created the first strong-current pulse-periodic nanosecond accelerator `Sinus.'