75 years of the Dzhelepov Laboratory of Nuclear Problems

From the history of the Dzhelepov Laboratory of Nuclear Problems

Excerpts from the article by V.P.Dzhelepov

The beginning of the history of Dubna as a place where one of the world's largest centres of the latest nuclear research was established in a relatively short period of time dates back to the second half of the 1940s. In those difficult post-war years, on the initiative of the outstanding scientist of our country, Director of the Institute of Atomic Energy (IAE), Academician I.V.Kurchatov and a number of other nuclear scientists, in order to develop promising fundamental research in the field of elementary particle physics and the atomic nucleus at high energies in the USSR, the government of our country in 1946 made a decision to develop and build by the end of 1949 the largest particle accelerator in the world at that time - a synchrocyclotron with a pole diameter of five meters.

For this purpose, it was decided to organize a branch of the IAE, assigning it the name "Hydrotechnical Laboratory" of the USSR Academy of Sciences for reasons of secrecy and to locate it relatively close to Moscow. M.G.Meshcheryakov was appointed Director of the branch and Scientific Leader of the accelerator project and V.P.Dzhelepov was appointed his Deputy (both were then Candidates of Physical and Mathematical Sciences). At the insistence of the so-called competent authorities, the village of Novo-Ivankovo (later, the city of Dubna), located on the right bank of the Volga, near the first lock of the Volga-Moscow water canal, was chosen as the location for the branch.

I.V.Kurchatov and V.P.Dzhelepov. 1959

Due to the tight deadlines for the construction of the accelerator and the science campus, all construction and equipment manufacturing work at the country's factories was carried out at a very high pace and under strict control. With extreme effort from the Laboratory staff and cooperating enterprises and institutes, the accelerator was constructed and put into operation strictly on time - for the seventieth anniversary of I.V.Stalin on 21 December, 1949. On the night of 14 December, 1949, deuterons were accelerated at the synchrocyclotron to an energy of 280 MeV, later, particles - to 560 MeV and afterwards, protons - to 480 MeV. In 1951, the leaders of this work and the employees that made a significant contribution to it were awarded the USSR State Prize for the construction of the accelerator. Systematic physical research began almost immediately after the launch of the accelerator.

The commissioning of the five-meter synchrocyclotron and the beginning of research on it marked the birth of high-energy nuclear physics in our country.

The Laboratory rapidly filled up with scientific personnel. Particularly valuable was the arrival of the outstanding Italian physicist, professor (in the future, Academician of the USSR Academy of Sciences) B.M.Pontecorvo to work at the HTL in 1950. In the same year, the famous scientist M.S.Kozodaev began working in the Laboratory. Every week, prominent theorists I.Ya.Pomeranchuk, Ya.A.Smorodinsky, B.M.Migdal and B.T.Geylikman came from Moscow to scientific seminars of the Laboratory to give lectures and to discuss programmes and experimental results. They also supervised the young theorists of the Laboratory (L.I.Lapidus, V.G.Soloviev, B.M.Barbashov, N.A.Chernikov, S.M.Bilenky, R.M.Ryndin). All this significantly increased the scientific potential of the Laboratory. At the end of 1953, after a significant reconstruction of the synchrocyclotron (increasing the diameter of the magnet poles to six meters and replacing a number of other units), protons with an energy of 680 MeV were obtained at the accelerator and a series of beam channels for protons, neutrons and pions were produced. [...]

In 1953, a significant group of Laboratory scientists were awarded the USSR State Prize for relevant scientific results obtained at the accelerator. That same year, our branch acquired the status of an independent institute that was named the Institute of Nuclear Problems (INP) of the USSR Academy of Sciences.

In 1956, JINR, founded on the basis of the Institute of Nuclear Problems of the USSR Academy of Sciences with an operating synchrocyclotron, became the first base for scientific research by the international team of JINR Member States. [...]

DLNP Deputy Director L.I.Lapidus (on the right) is introducing the experimental equipment of the laboratory
to the American writer M.Wilson (in the centre). 1958

The operating accelerator and a significant number of physicists at DLNP that had been successfully carrying out research in the new field of nuclear physics for a number of years immediately attracted the attention of scientists from all countries that had become Member States of JINR.

As a result, already in the early 1960s, the number of foreign specialists working at DLNP reached 70-80 people and in the 1970-1980s, when research at the 70 GeV accelerator in Serpukhov started by the Laboratory, their number was 150-170 people. I will emphasize right away that usually in those years, about a third of all foreign specialists at JINR worked at DLNP, not counting a significant number of employees from Georgia, Azerbaijan, Armenia and the republics of the Central Asia. In the 1960-1970s, the Laboratory staff increased almost three times as compared to 1956.

Director of the Laboratory of Nuclear Problems Professor V.P.Dzhelepov
is introducing the experimental equipment to F.Joliot-Curie. 1958

New Departments were organized: of Weak and Electromagnetic Interactions (headed by Professor B.M.Pontecorvo), of Nuclear Spectroscopy and Radiochemistry (headed by Doctor K.Ya.Gromov), of Nuclear Electronics (headed by Doctor A.N.Sinaev), Theoretical Sector (headed by Deputy Director of DLNP Doctor L.I.Lapidus), departments, by whose efforts, together with the Design Bureau, Laboratory workshops, JINR PP and partially with factories, large facilities for research at the accelerator in Serpukhov were designed. They were headed by Doctors of Sciences Yu.M.Kazarinov, A.A.Tyapkin, Yu.A.Budagov, S.A.Bunyatov, V.I.Petrukhin (later, G.V.Mitselmakher), L.L.Nemenov.

To accommodate all these new departments, several well-equipped new buildings were built with the support of JINR Directorate. In order to provide the developing scientific departments with a technical base, the Laboratory workshops were also expanded about three times, equipped with the first-class Czechoslovakian machine tools. The Design Department was almost doubled.

An essential task for the Directorate of the Laboratory and Department was to develop a research programme that would take into account the interests of both the employees that currently work and those that came to the Laboratory from the Member States, as well as to expand the programme in accordance with the possibilities of implementing qualitatively new research on accelerators that produce particles with energies many times greater. Another, no less complex task was the implementation of the scheduled programmes.

First of all, it was necessary to increase the pace and quantity of research carried out on our own accelerator. It required imparting new qualities to the accelerator: increasing the current of the accelerated beam, producing new beams and increasing the reliability of the accelerator.

The major achievements of the Laboratory were: increasing the intensity of the accelerated proton beam of the synchrocyclotron by almost ten times (from 0.25 µA in 1956 to 2.3 µA in 1962 (headed by V.I.Danilov, A.A.Glazov)) and using the system of beam extraction from the accelerator with an efficiency of 5% developed by V.P.Dmitrievsky that provided a sharp increase in the intensities of secondary particle beams obtained from external targets.

The possibilities for implementing various experiments were significantly expanded thanks to the production of new beams of polarized protons and neutrons of various energies obtained from the decay of pions in a 15-meter hard-focusing channel manufactured from magnetic lenses (headed by B.I.Zamolodchikov, A.A.Kropin, V.S.Roganov).

As a result, the synchrocyclotron started operating regularly on a physical experiment not for 3.5 thousand hours a year, as it was in 1956, but for 6-6.5 thousand hours and by general recognition, became the best synchrocyclotron in the world. It allowed carrying out a range of investigations on the atomic nucleus and elementary particle physics, as well as obtaining many new scientific results, including those of the highest scientific significance. Among them are thirteen discoveries of new phenomena registered in the State Register of Discoveries of the USSR.

It is known that any accelerator that has achieved record parameters in beam intensity and quality, after a relatively short time (about 15 years) loses these advantages and becomes unable to provide conditions for obtaining new highly significant physical results.

Taking this into account, in 1959, DLNP Directorate decided to establish within the laboratory a department for the development of new high-intensity accelerators with an energy of about 1 GeV, headed by Professor V.P.Dmitrievsky.

Reconstruction of the synchrocyclotron. Installation. 1981

Under the supervision of V.P.Dzhelepov, V.P.Dmitrievsky and L.M.Onishchenko, mainly by the efforts of this department and NIIEFA, a working project of a new accelerator was developed - a high-current phasotron with a spiral variation of the magnetic field for proton energy of 680 MeV. Its construction and adjustment were completed in 1984. Since the end of 1984, it has been successfully operating in particle and nuclear physics and is also used for applied research. The beam parameters of the new accelerator and its reliability significantly exceed the capabilities of the former synchrocyclotron that had worked for 30 years and completely exhausted its resource.

During the construction of the new accelerator, a number of new pavilions and buildings were built: for housing the physical equipment and the measuring centre, for the YASNAPP-2 complex (ISOLDE type) with an ion separator, a laboratory for experiments requiring a low background of extraneous radiation. A system of new beam channels was also developed, including a beam of so-called "surface", very low-energy muons, a pavilion with a six-cabin complex of medical beams for the treatment of cancer patients was built.

The topic of physical research at the Laboratory of Nuclear Problems covers the field of both intermediate and high energies. DLNP scientists work at accelerators in Serpukhov, Geneva, Batavia, Saclay, Julich, Villigen and other centres.

DLNP is the second largest laboratory of JINR. Its staff consists of 625 employees, including 54 Doctors of Science and 130 Candidates of Science. A large number of specialists (about 350 people) from all JINR Member States have been awarded degrees and titles at DLNP.

From the collection of articles "The Joint Institute for Nuclear Research is 40 years old". 1996