Alexander Vladimirovich Strelkov, a leading researcher in the FLNP Sector of Fundamental Properties of the Neutron, began working in the Laboratory in 1960, after graduating from Gorky State University.

“Despite the fact that the professional activity of almost all the men in my family was related to physics (for example, four of my cousins were physicists and quite prominent scientists: all were doctors of science, some of them worked at the Kurchatov Institute, some at the Lebedev Physical Institute; my uncle was a professor at Moscow State University and headed the Department of Theory of Vibrations), at first I did not think about physics as a profession at all,” says Alexander Vladimirovich. “My father was the Head of the Electrophysical Laboratory of the large plant “Krasnoe Sormovo”. He brought home various devices and showed me physics experiments, which greatly influenced my hobbies and choice of future profession. Sometimes he even egged me on and suggested that I find an explanation for some effect. For example, explain the paradox of tea leaves in a glass of tea, which A.Einstein once noticed. As is known, in a centrifuge, in a liquid, particles with a lower density collect in the center and those with a higher density move to the periphery. But this does not work with tea leaves that lie at the bottom and are then stirred in the glass – instead of moving towards the walls of the glass, the tea leaves collect in the center. When the glass is standing and the liquid is rotating, a slowdown occurs on the walls, vortices form, which pick up and collect tea leaves in a pile at the bottom. I figured out how to test this experimentally: when I hung a glass of tea on a string and spun it, the tea leaves moved to the periphery, which explained this paradox.

But my attitude to science as a profession was shaped by my school physics teacher Vyacheslav Sergeevich Permitin. I was very lucky that I had such a teacher who explained the basics of physics to us in a very simple way, and put the most complex things in simple terms, even quantum mechanics. Moreover, he used to say: “An indivisible elementary particle passes through two holes simultaneously. Unfortunately, I myself don’t understand how a particle can also be a wave, but experiments confirm this fact.” He asked us interesting questions and set problems that captured my imagination and amazed me. He taught me how to solve tricky problems, which I then successfully solved at city Olympiads and won first prizes.

And so, when I had already been working in Dubna for five years, the doorbell rang. Vyacheslav Stepanovich stood on the threshold. He arrived without warning, since I didn’t have a phone at that time. He asked, laughing: “Will you let me in?” He came to me from Moscow, where at the Ministry of Education he was looking for an opportunity to meet with the author of a just published physics textbook, Academician I.K.Kikoin. He showed me a notebook in which he wrote down 50 errors-inaccuracies that he found in the textbook. He came to the Ministry of Education and was told that the author of this textbook worked at a “closed” institute, but he could leave them his notes to pass them on to Kikoin. I.K.Kikoin worked at the Kurchatov Institute, where I regularly went for experiments. Vyacheslav Stepanovich, of course, did not know this and simply came to visit me. I handed over the notebook to Kikoin through Yakov Abramovich Smorodinsky. About two weeks later, Kikoin's secretary contacted me and told me his words: "Yes, your teacher has very thoughtfully read our textbook.”

Vyacheslav Stepanovich asked me to show him the Institute and tell him what kind of research I was doing. But how could I show it on Sunday?! I called the Head of the Security Department, Nikolai Pavlovich Terekhin, and explained to him that my school physics teacher had unexpectedly come to see me, and asked if he could visit the Institute. And, surprisingly, he gave permission! What is more, when I told him that the teacher had a prosthetic leg and limped, he even provided us with a car. He called the Security Department and made arrangements for us, so in the Neutron Lab we could tour the IBR reactor, and in the DLNP building No.1 we were allowed to visit the hall of the synchrocyclotron that was even specially shut down for us for a while.

The scientific fate of Alexander Vladimirovich was largely determined by Fyodor Lvovich Shapiro, LNP Deputy Director from 1959 to 1973. In 1960, he initiated work in the Laboratory to study the Mössbauer effect in order to experimentally prove the principle of equivalence of gravitational and inertial masses. A.V.Strelkov immediately joined this research project. Unfortunately, in a similar experiment, American physicists R.Pound and G.Repke were ahead of our group and were the first to demonstrate a shift in the frequency of gamma-rays in the Earth’s gravitational field. In the mid-1960s, A.V.Strelkov participated in experiments on critical neutron scattering at the IBR reactor, in which the absence of an anomaly in the diffusion coefficient at the liquid-vapor critical point was shown. And later, with the participation of Alexander Vladimirovich, research activities began, which still continue today, first on the discovery and then on the study of ultracold neutrons (UCN). The discovery of UCN turned out to be quite dramatic. In August 1968, in the midst of the holiday season and just two weeks before the shutdown of the first IBR reactor, thanks to the inexhaustible energy and perseverance of F.L.Shapiro and the enthusiasm of young researchers V.I.Lushchikov, Yu.N.Pokotilovsky and A.V.Strelkov, the research group succeeded in confidently registering the phenomenon of confinement of slow neutrons in traps, which was later recognized as a discovery.

Later, A.V.Strelkov began studying the anomaly of UCN storage. The first decisive experiments were carried out by Alexander Vladimirovich and his colleagues at the most powerful reactor in the Soviet Union at that time in Melekes; he later compiled a list of 16 Soviet and foreign reactors that he had visited and some of which he had the opportunity to work on. On the initiative and with the participation of A.V.Strelkov, a UCN production facility was developed at JINR for the BIGR pulsed reactor at VNIIEF in Sarov, with the help of which the possibility of transporting UCN from the reactor in closed vessels was demonstrated for the first time. Then experiments to study the anomaly of UCN storage continued; the Big Gravitational Spectrometer was designed and built. It was with this spectrometer that the phenomenon of UCN heating in the range of low energies was discovered and the effect of neutron cooling upon hitting a hot wall was detected. This effect still has no satisfactory explanation. In parallel, A.V.Strelkov was engaged in an experiment at the JAGUAR reactor at VNIITF in Snezhinsk on the observation of neutron-neutron scattering, dreaming of conducting an experiment on direct observation of neutron scattering by neutrons. So why did he choose physics as his life's work?

– I have no regrets about the profession and path I have chosen. Of course, my students have long outgrown me, and I have been working under their direction for a long time. There was even a joke going around at the Laboratory: if you want to become the FLNP Director, go to Strelkov’s group. For example, after graduating from University, Valera Shvetsov worked in my group, and later became FLNP Director. I was the supervisor of his PhD thesis, as well as the dissertation work of Egor Lychagin. Nowadays, our young people complain that it is hard to work in physics: there are practically no grants for fundamental research projects, researchers have to somehow maneuver and rely only on their own forces to go on with their research... It's sad to admit, but in 30 percent of cases they are right. At such moments, I always think of Fyodor Lvovich Shapiro, who had only physics in his head, and not all this worldly fuss and politics.