artem isaak alikhanian (1908–1978) (biographic sketch)

8
Artem Isaak Alikhanian (1908–1978) (Biographic Sketch) H. M. Asatryan and T. G. Hambardzumyan Alikhanian Yerevan Physics Institute, Yerevan, Armenia Received March 3, 2009 AbstractA.I. Alikhanian is one of founders of experimental nuclear physics in USSR. Starting and development of the atomic nuclei, cosmic ray, and elementary particle physics in Armenia relates to the name Alikhanian. He created the Aragats and Nor-Amberd high-altitude cosmic stations and the Yerevan Physics Institute. He made an essential contribution into the development of high-energy physics and played a significant role in creation of methods of recording high-energy particles. PACS numbers: 96.50.S, 29.17.+w DOI: 10.3103/S1068337209050016 Key words: Artem Alikhanian, nuclear physics, cosmic rays, elementary particle physics It was his destination to change the appearance of this piece of Armenian land and he, as a creator of physical science in Armenia, should be ranked among the Enlighteners of Armenia”. Academician A.B. Migdal A.I. Alikhanian June 24, 2008 it was 100 years of birth of Artem Isaak Alikhanian, the famous soviet scientist in the field of nuclear, cosmic ray, and elementary particle physics, corresponding member of AS of USSR and member of AS of Armenian SSR. A.I. Alikhanian belongs to the outstanding cohort of soviet scientists who created nuclear physics in USSR in nineteen thirties–sixties. These great enthusiasts of science could enrich it with original investigations, created scientific schools, headed large teams of researchers able to solve large-scale scientific problems. Starting and development of the experimental nuclear physics in Armenia relates to the name Alikhanian. Due to his inexhaustible energy, the Aragats and Nor-Amberd high-altitude cosmic stations and the Yerevan Physics Institute had been created and the 6-GeV synchrotron constructed. All this many-sided activity placed Armenia aside many advanced countries of the world and his brainchild, ISSN 1068-3372, Journal of Contemporary Physics (Armenian Academy of Sciences), 2009, Vol. 44, No. 5, pp. 209–216. © Allerton Press, Inc., 2009. Original Russian Text © H.M. Asatryan, T.G. Hambardzumyan, 2009, published in Izvestiya NAN Armenii, Fizika, 2009,Vol. 44, No. 5, pp. 315–329. 209

Upload: h-m-asatryan

Post on 02-Aug-2016

214 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

H. M. Asatryan and T. G. Hambardzumyan Alikhanian Yerevan Physics Institute, Yerevan, Armenia

Received March 3, 2009

Abstract⎯A.I. Alikhanian is one of founders of experimental nuclear physics in USSR. Starting and development of the atomic nuclei, cosmic ray, and elementary particle physics in Armenia relates to the name Alikhanian. He created the Aragats and Nor-Amberd high-altitude cosmic stations and the Yerevan Physics Institute. He made an essential contribution into the development of high-energy physics and played a significant role in creation of methods of recording high-energy particles. PACS numbers: 96.50.S−, 29.17.+w DOI: 10.3103/S1068337209050016 Key words: Artem Alikhanian, nuclear physics, cosmic rays, elementary particle physics

“It was his destination to change the appearance of this piece of Armenian land and he, as a creator of physical science in Armenia, should be ranked among the Enlighteners of Armenia”.

Academician A.B. Migdal

A.I. Alikhanian

June 24, 2008 it was 100 years of birth of Artem Isaak Alikhanian, the famous soviet scientist in the

field of nuclear, cosmic ray, and elementary particle physics, corresponding member of AS of USSR and member of AS of Armenian SSR. A.I. Alikhanian belongs to the outstanding cohort of soviet scientists who created nuclear physics in USSR in nineteen thirties–sixties. These great enthusiasts of science could enrich it with original investigations, created scientific schools, headed large teams of researchers able to solve large-scale scientific problems.

Starting and development of the experimental nuclear physics in Armenia relates to the name Alikhanian. Due to his inexhaustible energy, the Aragats and Nor-Amberd high-altitude cosmic stations and the Yerevan Physics Institute had been created and the 6-GeV synchrotron constructed. All this many-sided activity placed Armenia aside many advanced countries of the world and his brainchild,

ISSN 1068-3372, Journal of Contemporary Physics (Armenian Academy of Sciences), 2009, Vol. 44, No. 5, pp. 209–216. © Allerton Press, Inc., 2009. Original Russian Text © H.M. Asatryan, T.G. Hambardzumyan, 2009, published in Izvestiya NAN Armenii, Fizika, 2009,Vol. 44, No. 5, pp. 315–329.

209

Page 2: Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

ASATRYAN, HAMBARDZUMYAN

210

JOURNAL OF CONTEMPORARY PHYSICS (ARMENIAN Ac. Sci.) Vol. 44 No. 5 2009

Yerevan Physics Institute, to the level of such scientific centers as Harvard University in USA and DESY Laboratory in Germany.

Saying of Academician A.B. Migdal, given as epigraph to this outstanding biography, reflects well the destination and role of A.I. Alikhanian as brilliant organizer of science who predetermined basically its subsequent development in Armenia.

Artem Isaak Alikhanian was born on 24 June 1908 at Kirovabad (Yelisavetpol, Gyanja). His father, Isaak Abrahamovich Alikhanov, was a locomotive driver at the Transcaucasian railroad and mother, Yulia Artemovna Sukhanova, was housewife. The family had three more children: elder son Abraham and two daughters, Araksia and Ruzan. In 1918 the family moved to Aleksandropol, but in 1920 they were forced to escape to Tiflis from Turkies. The life of brothers started in different ways: the elder, Abram, learned at the Tiflis Commercial School, while the younger, Artem, learned only a year and was expelled for nonpayment. He delivered newspapers, running about Tiflis’ streets, packed up citric acid, and served tea in a half-legal pub for opium smokers. In the life of Artem Isaakovich extraordinary circumstances arose frequently. He recollected, for example, how he with his father, in years of Revolution, shot at “white” Cossacks with a machinegun from the moving train and how they sheltered in their cellar Ter-Stepanov, the Head of May Insurrection in Leninakan, transferring him then to Georgia by locomotive.

Chance meeting with a beginner medic turned to be determining: he trained the boy for exams; Alikhanian entered the eighth form of the Labor School no.100 in Tbilisi, and received a certificate after passing examinations without attending lectures. In 1926, getting a grant for studies from the Transcaucasian railway labor union, he left for Leningrad. A.I. Alikhanian told that he applied in Leningrad for three high schools at once (Polytechnic Institute, Nautical School, and University), but after some hesitating between sea and mathematics he had chosen the latter. After having taken a course of electromagnetism he got fond of physics and was true to that up to the end of his days. Two years before graduating from university in 1930 he succeeded to work at the Leningrad Physical-Technical Institute (LFTI) headed by the patriarch of soviet physics A.F. Ioffe. Atmosphere of romantic scientific research of famous “phystech” seminars predetermined the style of all his subsequent scientific activity. His first works were in crystal physics, X-ray physics, and fast electron diffraction. But very soon he became keen on studies of atomic nuclei, like physicists throughout the world. At that time it was already understood in the Lab that in order to obtain significant results novel experimental techniques must be developed. In particular, one of the most powerful methods of investigation at that time had been the Danish technique of magnetic spectrometer. With use of this device, improved by Alikhanian brothers and coworkers, a new phenomenon had been discovered: creation of electron–positron pairs at internal conversion of gamma-quanta. The majority of works on pair conversion, published at that time in world literature, were from the group of Alikhanov–Alikhanian.

When Joliot-Curie discovered the artificial radioactivity, the Brothers succeeded, due to the same powerful high-aperture magnetic spectrometer, to measure the spectrum of positrons produced by artificial radioactivity. Alikhanians started to study the synthesis of radioactive elements by irradiating beryllium and aluminum with alpha-particles. Investigation of radioactive elements was the main direction of the Laboratory until serious doubts appeared about the validity of the energy conservation law in elementary processes. Pauli hypothesis on the existence of neutrino provoked at that time much doubt. It was just the problem of existence of neutrino that became the essence of the energy conservation question. Alikhanian proposed to check the energy and momentum conservation laws for a unit event in the process of electron-positron annihilation. Alikhanian, together with Alikhanov and Artsimovich, proved in a brilliant experiment the validity of these laws in the annihilation process. Alikhanian used to say it was a triumphal period of the Lab, since it was concerned with the common philosophy of the particle physics.

On 9 May 1937 A.I. Alikhanian defended his PhD thesis “Absorption of hard X-rays”. Opponents were V.M. Dukel’skii and D.V. Skobel’tsin. A year before, A.F. Ioffe, giving Alikhanian a testimonial, wrote that he had wide erudition and is an excellent experimenter. On 11 September 1939 he defended his Doctor’s dissertation “Experimental investigations on beta-decay” and became Professor in the same year. In 1941 Alikhanian brothers had been awarded the State (Stalin) Prize of USSR for the series of works on gamma-ray conversion and for studies of radioactivity.

In that period the gift of Artem Isaakovich had especially bright been displayed. It was just Alikhanian who proposed the idea to use cosmic rays as a source of high-energy particles, since during propagation of cosmic radiation through the Earth’s atmosphere nuclear processes take place in the latter.

In spring 1939 in Laboratory of Alikhanov works started on studies of cosmic rays and the first results of investigation of ultrahigh (for that time) energy electrons had been obtained. It was necessary to

Page 3: Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

ARTEM ISAAK ALIKHANIAN

211

JOURNAL OF CONTEMPORARY PHYSICS (ARMENIAN Ac. Sci.) Vol. 44 No. 5 2009

perform further measurements at high altitudes of mountains. In 1940 a small group of physicists of the Alikhanov Lab travelled to Elbrus. Alikhanov revealed there that contradictions were observed between readings of two devices, the particle counter and ionization chamber. The high-altitude registrations of these counters differed crucially.

For continuation of studies Pamir was chosen as the base and the preparation of expedition began. The program of expedition had been considered at the meeting of the Presidium of AS of USSR and approved by a special Resolution. The expedition was planned for June–September 1941. The purpose of the Pamir expedition was study of cosmic rays at the highest for that time altitudes of 6000 m above sea level. However, the War began and disturbed the plans.

During the offensive of German troops, in order to solve the problems of defense of Leningrad and of creation of new models of military equipment and weapon, a Military-Technical Commission has been organized upon initiative of scientists; the Commission was headed by Academician N.N. Semyonov. Artem Alikhanian also entered this Commission. The Commission considered and realized a flow of rationalization defense proposals. At a meeting in “Phystech” Artem Isaakovich was one of the first to sign up for volunteer corps and was right away sent at the disposal of Navy to the especially dangerous region of the Leningrad front, Kronstadt, where he had a mission to perform scientific works on defense themes. Soon after that the Government decided to recall from the Army some specialists who were needed for the most important works on the home front; among them was Artem Alikhanian. But he continued to fly periodically to Leningrad crossing the front line to take part in the activity of the Commission on realization of defense proposals. These flights were extremely dangerous and provoked amazement of many colleagues.

For continuation of scientific research suspended because of war, Alikhanian and Alikhanov addressed a request to Academician S.I. Vavilov and the Vice-President of AS of USSR L.A. Orbeli for authorizing an expedition in summer 1942 to study cosmic rays on the Aragats Mountain in Armenia. The expedition had been authorized and Alikhanian was given instructions from the Central Committee of Armenian Communist Party to join one of partisan detachments in case of German breakthrough Caucasus.

On 5 May 1942 the “Certificate of the Head of the high-altitude expedition of LFTI departing to the Armenian SSR for implementation of the program of investigation of cosmic rays” was issued to A. Alikhanov. Included in expedition were: A.I. Alikhanov, the Head; A.I. Alikhanian, Doctor of Phys.-Math. Sci., LFTI; P.K. Spivak, Candidate of Phys.-Math. Sci., LFTI; V.I. Kalashnikova, Candidate of Phys.-Math. Sci., LFTI; I.Ya. Pomeranchuk, Doctor of Phys.-Math. Sci., PIAS; G.M. Mirianashvili, AS of Georgian SSR, Tbilisi; V.N. Kizilbash, AS of Georgian SSR, Tbilisi; S. Zurabyan, Yerevan State University (YSU); N.M. Kocharian, YSU; L.M. Nemenov, Candidate of Phys.-Math. Sci., LFTI; A.F. Kirpichev, LFTI; D.T. Shkarlet, radio operator, weather station.

Narrating about the first expedition, full of expected and unexpected difficulties, Artem Isaakovich used to note that they reckoned upon the assistance in Armenia, because they knew that N.M. Kocharian, who was some time busy with cosmic rays, worked in Yerevan. However, the first ascent of Aragats was truly a heroic epopee. The equipment had first been transferred from blockade Leningrad to Kazan’, then down the Volga, past Stalingrad, which already was bombarded, to Astrakhan’, then by Caspian to Baku, and after that to Yerevan. During ascent from Byurakan up the Mountain of Aragats new difficulties arose. There were no roads and there was no question of cars. All horses were mobilized and the only hope was that Byurakan peasants provide donkeys. Twenty eight kilometers of ascent of Aragats over wild slopes with two tons loaded donkeys turned to be the most difficult. The most fragile equipment, such as counters, radio valves, and radio circuits, was carried by scientists themselves. On the Aragats Mountain, at the height of 3250 m, an encampment was made for performing the first studies.

The task of the 1942 expedition was investigation of the anomaly in the behavior of cosmic rays: the soft component revealed a higher ionizing power than could be expected from its known composition (electrons, positrons, muons, and photons). The obtained results confirmed the hypothesis of Alikhanov and Alikhanian that there are also protons in the soft component.

In 1942 discussions started on the question of organization of the Physics Institute in Yerevan and on 1 November 1942 it was organized by the order of YSU Rector; Professor Abraham Alikhanov was appointed the Director and Alikhanian was appointed Professor of General Physics Chair at YSU. In the Alikhanian’s report on the supposed staff of the Physics Institute under the YSU the structure and number of coworkers is indicated, eight persons and a vacancy for laboratory assistant.

When the AS of Armenian SSR has been organized, the Physics Institute of YSU was transferred to the Academy system according to regulation NC-702 on 20 November 1943 and Alikhanian was appointed its Director. Simultaneously with the appointment to the position of Director he was in December 1943 appointed the Head of one of laboratories of an LFTI group evacuated to Kazan’.

Page 4: Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

ASATRYAN, HAMBARDZUMYAN

212

JOURNAL OF CONTEMPORARY PHYSICS (ARMENIAN Ac. Sci.) Vol. 44 No. 5 2009

In summer 1943 Artem Isaakovich, after equipping and discussing with Alikhanov the plan of investigations, began to prepare the next expedition to Aragats. There appeared an unexpected difficulty to transfer the equipment to Yerevan in conditions of war when no free transport facility was available. Alikhanian used to tell that the Armenian Permanent Mission under the USSR Government provided any possible support. They recommended appealing to General Staff for an airplane and so the question of transfer by air was solved, but there was no vehicle to deliver the equipment to the Vnukovo Airport. Then the Presidium of AS of USSR appealed to the Krzhizhanovskii (the famous revolutionary of nineteen twenties) Museum where a car was exhibited presented him by Lenin. It had wooden radii and moved at a velocity of 20 km/h after being reanimated. By this car the equipment had been brought to the airport.

In July–August 1943 the second Aragats expedition occurred with the personnel consisting of researchers from LFTI, YSU, and AS of Georgian SSR. During that expedition the measurements performed in 1942 had been repeated and in addition the absorption of the soft component in water was measured. In the 1943 expedition Alikhanian with coworkers established finally the third, proton, component of cosmic rays and showed that it decreases e times per one meter.

Another result of the 1943 expedition was a new type of showers discovered by A. Alikhanian with T. Asatiani and N. Shostakovich; these showers were called “narrow”. In them photons have been revealed, along with penetrating particles. Discovery of these showers indicated for the first time that the non-electromagnetic processes occur intensely when cosmic rays propagate in the atmosphere. Only after discovery of π0-mesons decaying into two photons, the presence of photons in these showers was explained. At the same time Alikhanian and Asatiani proposed and realized a new method of investigation of the structure of showers, the method of area variation, which allowed revealing in the composition of primary cosmic radiation ultrahigh-energy particles (of the order of 1014 eV). This method became later, throughout the world, the basic technique of studies of extended atmospheric showers.

In 1943 Alikhanian and Alikhanov had been elected members of AS of Armenian SSR. In 1945 Alikhanian was awarded to the order of Labor Red Banner and in the same year he was nominated for the elections to AS of USSR and for the State Prize.

In 1946 the Ministry of Internal Affairs sent him to Germany on a special mission to choose trophy equipment for the Physics Institute of AS of Armenian SSR.

In these years Alikhanian, Alikhanov, and coworkers proceeded to systematic investigation of the nature and spectra of particles of cosmic radiation. They created in 1946 a new device for study of cosmic rays, which then was called Alikhanian–Alikhanov magnetic spectrometer.

Discovery of the third component of cosmic rays, discovery of narrow showers, discovery of neutral particles in extended Auger showers, and employment near the peak of Aragats, at the height of 3250 m, of a super strong magnet produced domestically were marked, at the meeting of AS Presidium on 30 January 1946, among the most essential successes achieved in 1945 in investigations of cosmic rays.

On 5 April 1946 the decree of Armenian Government had been issued on organization of a stationary station on Aragats, under the Physics Institute, for studies of cosmic rays and on the necessity of constructing in Yerevan a building of Institute. The process of formation of the Yerevan Physics Institute (YerPhI) lasted from 1942 to 1946. It is now hard to imagine how it was succeeded in difficult years of World War II to lay a road to the peak of mountain, to install electrical equipment, to construct experimental arrangements with large magnets, and to organize functioning of scientific laboratories. Which resoluteness and strength of persuasion lead this outstanding man, who said at that time: “It is hard to be at the leading front of science: one needs to overcome the psychological barrier and to have fearlessness”. Creation of the Institute played a great role for the entire subsequent development of physics in not only Armenia, but the whole USSR.

In 1947 the second mass-spectrometer of the Aragats station, the “big magnet”, had been set in operation, which was used for studies of spectra of masses and momenta of cosmic particles. For the first time an idea was suggested on instability and interconvertibility of particles with intermediate masses.

Government and Party bodies made a great account of and rated very high the works performed on Aragats. For a series of works on cosmic rays Alikhanian and Alikhanov were awarded in 1948 the Stalin Prize. At that time development of physical research became one of priority directions of science in Armenia. By a USSR Government resolution of 8 February 1948 YerPhI was enjoined to provide comprehensive studies of cosmic rays.

Alikhanians activity stimulated search for new particles in cosmic rays, performed in different countries during the next decade.

In 1950–1952, after performing works on improving the magnetic spectrometer combined with the

Page 5: Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

ARTEM ISAAK ALIKHANIAN

213

JOURNAL OF CONTEMPORARY PHYSICS (ARMENIAN Ac. Sci.) Vol. 44 No. 5 2009

Wilson chamber, Alikhanian with coworkers showed that particles with the mass between those of π-meson and proton have relatively long lifetimes (longer than 5×10−9 s). Later it was established that the lifetime of K-mesons amounts to 10−8 s.

On the basis of studies performed at the Institute, a program of works of YerPhI for the period 1956–1960 was developed. It was recommended to YerPhI by the USSR Government regulation to concentrate upon the following themes: interaction of nuclei with nucleons at the energies higher than 20 GeV; mechanism of creation of π- and μ-mesons by protons and neutrons of cosmic radiation; mass spectrum of particles of cosmic radiation; properties of nuclear-inactive particles.

Simultaneously with the extensive research the work areas were being improved. In 1949 the main building of PIAS of Armenia (Baghramyan Street) had been commissioned. In the same year construction of the laboratory building of the high-altitude Aragats station was started and completed in 1950.

In 1960 on initiative and under guidance of Alikhanian on the slope of Aragats at the height of 2000 m the cosmic station Nor-Amberd had been created where systematic studies of interaction of high-energy nucleons with nuclei and methodological investigations were performed. The Aragats and Nor-Amberd stations were first in the USSR cosmic stations operating year-round.

One of participants of high-altitude expeditions, Professor of Moscow Engineering and Physics Institute (MEPI) B.I. Luchkov recalled: “There, at the upper Aragats high-altitude station, а close company of MEPI-people got together. I will never forget this exile to south and be forever grateful to Artem Isaakovich for that. It was a bright world of Scheherazade tales interspersed with stern everyday of genuine physical experiment, a practical school on all parts of physics… Alikhanian was a large-scale person, who did not squander his gifts on trifles. He simply had not time for those. He was a bulk of energy, of spirit of enterprise, of restrained but deep feelings. Easterly sage and naive, he could be both a dodgy politician and a man with childish open soul. I learned his persistence and prehensility in solving physical problems and his gentleness and ability to forgive in things like that do happen…”

All these years the main interest of Alikhanian was connected with YerPhI and high-altitude stations on the Aragats Mountain. But also of great importance was his activity in leadership of Moscow Laboratory which he created in 1943 as a part of the Laboratory no. 3 of AS of USSR (ITEP at present) and headed it up to very last days of his life. In 1951 this lab had been transferred to PIAS and it was for a long time called “Alikhanian Laboratory”.

The relatively small Moscow Lab was of special importance for Alikhanian. It became in 1945–46 a “firing pad” for preparation and development of many year’s program of studies of cosmic radiation and there was based essentially the Alikhanian’s activity on creation of the scientific center in Armenia. Considerable support in this activity had been provided from Moscow institutions, Lab no.3 and later the Institute of Physical Problems. They sent a large amount of devices, materials, units, various facilities, and technical supply items for the Aragats station.

Many young physicists from Armenia learned in this lab. Alikhanian made account of exchange of experience, strongly supported creative initiatives of coworkers promoting their realization in every possible way, and steadily informed lab coworkers on scientific news picked up at conferences, discussions, and private communications.

In works of this period (before 1956), by means of direct measurements of momenta, paths, and ionizing powers of particles, their masses had been determined. With use of ultrastrong mass-spectrometric techniques, in high-altitude cosmic radiation protons, neutrons, deuterons have been revealed, spectra of protons, muons, electrons, and positrons, as well as cross-sections of interaction and recharging of fast protons were measured. Processes of scattering of muons in plates of Wilson chamber were studied. With use of magnetic spectrometer mounted in the underground lab of Moscow State University (at the depth of 40 m of water equivalent) spectrum of low-energy muons was measured.

In the middle of nineteen fifties the center of interests of physicists busy with elementary particles moved to the experiments on large accelerators. Alikhanian and coworkers performed at that time works dealing with different properties of elementary particles. In particular, studies of the π→μ→e decay observed in a bubble chamber confirmed the violation of parity conservation in this process. The most precise, for that time, investigation of scattering by nuclei was performed. The most interesting was apparently the experimental study of the decay of long-living neutral K2-meson into three neutral pions. This decay follows directly from the conservation of CP-invariance and its checking was of fundamental interest. The experimental solution of this problem was concerned with the biggest at that time 570-liter freon bubble chamber, created by Alikhanian with coworkers, with use of which it was succeeded to reveal more than hundred events of the decay searched for. The obtained results entered the International Summary Table of properties of elementary particles.

Page 6: Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

ASATRYAN, HAMBARDZUMYAN

214

JOURNAL OF CONTEMPORARY PHYSICS (ARMENIAN Ac. Sci.) Vol. 44 No. 5 2009

In 1956 a new stage began in the scientific biography of Artem Alikhanian. At the meeting of Scientific Council of YerPhI the question was considered of designing and constructing a modern accelerator of charged particles. In 1957 it was decided by a Government resolution to construct a ring electron accelerator (REA) in Yerevan. When the Armenian Government allocated a place for the construction of accelerator and the residential community, Alikhanian with a small group of coworkers went to view the place. Four hundred meters after passing the Kiev Bridge there was no road. When it was nevertheless succeeded to reach the place, they saw a deserted area full of field stones and snakes and scorpions dwelling there. It seemed to be impossible to build there anything, but Alikhanian, full of optimism, pronounced: “All I will make will be here: Physics Institute, laboratories, powerful accelerator underground, town, square, hotel, houses for workers – three-storey modern cottages, shops, kindergarten, clinic, conference hall, and passage through a poplar avenue”.

So, the work on designing the biggest in USSR and one of the biggest in the world electron synchrotron for the energy of 6 GeV, started on initiative and under guidance of Alikhanian. It was imagined an extremely difficult problem – to construct such a complex machine remote from big scientific and industrial centers producing needed equipment. A number of famous scientists called the started designing-building works Alikhanian’s adventure. A spare budget of AS of Armenia was far insufficient for such a grandiose construction. Alikhanian understood well this fact and placed YerPhI in 1962 under the authority of the USSR’s State Committee of Atomic Energy (SCAE). This enabled to receive the needed financial and material-technical support for construction of REA.

The realization of the grandiose Project began in 1956. The physical design of accelerator was developed by YerPhI specialists under guidance of A.I. Alikhanian and Yu.F. Orlov. The technical design was made in Leningrad under leadership of E. Komar. The estimate documents were elaborated in Moscow. Construction of the accelerator, erection, adjustment and alignment works were performed by 18 building organizations of the USSR Ministry of Medium Machinery. From various enterprises of USSR equipment began to arrive (blocks of electromagnets, injectors, and high-frequency and vacuum facilities). Strong exaggeration reigned in the Institute, number of workers raised from 100 to 3000 after 1950. New departments, laboratories, and services appeared because of large volume of works.

Alikhanian steadily took care of preparation of personnel for working at the being-built REA; he sent young specialists for training to scientific centers in USSR and abroad for gaining experience in working with electron and gamma beams. Simultaneously primary researches were planned and necessary experimental arrangements prepared. During 1960 42 works were performed and published and 13 works reported at conferences.

Reception of the Yerevan electron accelerator for combined adjustment took place on 26 December 1966 and its launch was planned to be at 50-th anniversary of October Revolution. In the certificate of 25 October 1967 it is indicated that the physical launch of REA is completed, the energy of 6.1 GeV, exceeding the planned one, is obtained, discharge of the beam onto an internal target is realized, a gamma-beam is obtained, and works on performing physical experiments started.

After launch of REA studies of photoproduction of mesons on nucleons and nuclei were performed including those with use of a unique beam of polarized gamma-quanta produced in diamond crystals on the basis of coherent bremsstrahlung; this effect had been theoretically predicted earlier by M.L. Ter-Mikaelian. Later on this accelerator the emission of relativistic electrons at their channeling in crystals was observed and studied.

Development by G.M. Garibian and K.A. Barsukov of the Ginzburg–Frank transition radiation theory showed that the predominant portion of the transition radiation energy is concentrated in the X-ray frequency range and that it increases proportionally to the particle energy. Alikhanian, who had much experience of work with X-rays, realized at once that the X-ray transition radiation (XTR) may be applied to identification of ultrarelativistic charged particles.

General supervision of works on investigation of transition radiation of relativistic charged particles on the Yerevan accelerator had been realized by Alikhanian. In spite of the fact that because of low intensity of XTR the scientific community treated with distrust the idea of employing this radiation for needs of high-energy physics, Alikhanian succeeded to capture with this idea Moscow physicists of MEPI and PIAS. XTR of cosmic muons was for the first time measured in paper radiators at YerPhI in 1964. The report on this measurement did not raise much interest at the International Conference in Dubna. Turning point in the attitude of physicists towards XTR occurred when Alikhanian showed at conference in Kiev the photographs of tracks of electrons accompanied by XTR-quanta converted in the gas of the xenon strеаmer chamber producing photoelectrons. Besides, it was shown that XTR is produced effectively not only in periodic film radiators, but also in irregular porous materials of the type of foamed plastics. After

Page 7: Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

ARTEM ISAAK ALIKHANIAN

215

JOURNAL OF CONTEMPORARY PHYSICS (ARMENIAN Ac. Sci.) Vol. 44 No. 5 2009

that the interest of scientific community in XTR raised essentially and Alikhanian was invited to USA for lectures on XTR problems.

One of basic results of these studies was elaboration of physical principles of new-type devices – XTR detectors for separation and identification of ultrafast charged particles. Creation of this detector became especially topical for recording high-energy particles produced on big accelerators (hundreds of GeV), where the Cherenkov technique becomes inapplicable.

Alikhanian and Asatiani with coworkers are pioneers of creation of a new-type of spark chambers, the so-called track spark chambers. Developing and improving spark chambers with a large discharge gap, they placed such a chamber in a strong magnetic field and showed that the spark follows exactly the circular path of a charged particle. These chambers enabled gaining much more information on phenomena occurring in their working volume than the common spark chambers. The track spark chamber created as a result of long-term studies, became wide-spread all-round in the experimental high-energy physics. Alikhanian, Asatiani together with Moscow and Georgian physicists were for these works awarded the Lenin Prize.

Creation of track spark chambers and works on the search of effective inexpensive means for detection of ultrahigh-energy particles based on transition radiation in X-ray and optical ranges put in the forefront the Soviet experimental physics; this was claimed at XVI International Conference on High-Energy Physics in Batavia (USA) in 1972.

Academician Artsimovich wrote in 1972: “Yerevan Physics Institute has grown in 25 years into a big center of high-energy and cosmic ray physics, it is well known in the world due to studies in the field of cosmic rays and elementary particles, electrodynamics, theory of accelerators, and new techniques of detection of elementary particles. The Institute has in these fields a number of important successes having world recognition”.

Alikhanian paid a great attention to applied problems as well. For example, on his initiative and with his active support, investigations were started and developed in radiative study of materials, crystal physics, and biophysics with use of synchrotron radiation arising from motion of high-energy electrons in the magnetic field of the ring accelerator.

On Alikhanian’s initiative, the Annual School of Experimental and Theoretical Physics was organized at YerPhI. The first session of this School took place in 1961 in Nor-Amberd. It attracted many young scientists, active in high-energy physics, from all existing at that time institutions of corresponding specialization. The School enabled getting closer and establish personal contacts between the active physicists. Proceedings of the School were published yearly edited by Alikhanian and in some countries a part of Proceedings was translated from Russian. Schools under guidance of Alikhanian were among first examples of International Schools for young scientists.

In order to estimate the role of these Schools, it should be noted that in 1961–1975 a number of very important discoveries has been made in physics, such as parity nonconservation, strange particles and resonances, different types of neutrino, SU(3) symmetry, theory of Regge poles, quarks, and so on. Since the textbooks could not follow the rapid development of physics, the possibility to gain information directly from scientists of the research forefront can hardly be overestimated. Although all the Schools were very interesting and useful, the most remarkable was that of 1965. Giving lectures for “schoolchildren” were Gell-Mann, Lederman, Lee, and Schwartz, already being or future Nobel Prize winners, Goldhaber and Strauch, and many other prominent scientists. This gave a rare for that time opportunity to discuss with foreign colleagues many urgent problems of physics. The fact that these outstanding scientists came to Yerevan to take part in the School, was caused by the immense scientific prestige and personal charm of Alikhanian.

Professor Luchkov wrote: “Nor-Amberd Schools became the highest display of the spirit of Alikhanian’s YerPhI, its Renaissance… What a brilliant unity of scientific generations came here together every spring… Alikhanian’s Schools are his indubitable success as a great organizer of science, a bright link in the chain of achievements of home physics”.

In December 1971 the last organized by Alikhanian International School of Experimental and Theoretical Physics took place in Yerevan. Alikhanian and Orlov presented there the Project of electron-positron accelerator with colliding beams at total energy of 100 GeV. The Project contained several new ideas which have later been used in construction of the next-generation colliders; it was very close to the Project of the future LEP accelerator in CERN, which at that time was not even planned. The Project had not been realized because Alikhanian refused to strike off the list of authors the name of the dissident Orlov. According to Ioffe, if the Alikhanian–Orlov Project would have been accepted, the world center of high-energy physics would move to USSR.

Page 8: Artem Isaak Alikhanian (1908–1978) (Biographic Sketch)

ASATRYAN, HAMBARDZUMYAN

216

JOURNAL OF CONTEMPORARY PHYSICS (ARMENIAN Ac. Sci.) Vol. 44 No. 5 2009

Here the civic courage of Artem Isaakovich must be noted: he took on Orlov as Principal Theoretician for calculations of accelerator, in spite that Orlov, famous dissident and human rights activist, former worker of ITEP, expelled in 1956 and excluded from the Party by resolution of the Presidium of CC of CPSU. YerPhI was under the same Ministry as ITEP, so Alikhanian run much risks taking on a blacklisted person. But he was guided by both business and moral considerations. Later on he could assure that Orlov was elected the corresponding member of the Armenian AS.

Artem Alikhanian, being a many-sided and creative personality, was fond of art. He liked passionately painting, had a very alert eye and observed at once the gifted. He supported anyway Minas Avetissian and Harutyun Galents, Martyn Petrosyan, Arto Chakmakchian, and Giotto (Gevork Grigoryan) in times hard for them. He supported financially M. Zoshchenko when the writer was persecuted in “fight against cosmopolitism” and the friend of disgraced Shostakovich. He said that the essence of a State system is determined by its care of talent and geniuses of its people.

According to Academician Amatuni, Artem Alikhanian knew very well the nature of society and the structure of power governing the country. All this knowledge enabled him choosing the optimum behavior in critical situations where sometimes occurred the Institute and himself as the Head. Alikhanian had not been the member of CPSU; it was the rarest exception in the high-ranking system where he as the fates decree lived and worked.

Last years of working at YerPhI relations of Alikhanian with SCAE became worse. It happened may be because officials did not understand well the needs of contemporary science and the Institute problems arising. Surely, the rebellious character of Artem Isaakovich and employing persons disagreeable with authorities made his personality inconvenient for SCAE officials. At that time a group of young lab managers had been formed who were discontented by the fact that the resources of the Institute are distributed uniformly among all scientific directions without taking into account the importance and prospectiveness of their works. They sent letters to SCAE and to Party bodies. This led finally to that Alikhanian was in 1973 relieved of his post of the Director of his brainchild. He joked in this connection bitterly: “A century ago people were exiled to Caucasus, but I am exiled, vice versa, from Caucasus to Moscow”.

After that Alikhanian concentrated himself completely on supervision of Moscow Laboratory of elementary particles under PIAS of USSR, which he created as early as in 1943.

Artem Isaakovich Alikhanian deceased in 1978 in Moscow. His life was a “high voltage” life having been materialized into a rich heritage, which he left for us – Yerevan Physics Institute, Laboratory in PIAS, Chair of Nuclear Physics at MEPI, “Aragats” and ”Nor-Amberd” high-altitude scientific stations, Ring Electron Accelerator, a large number of experimental works on cosmic rays and high-energy physics that enter the golden fund of modern experimental physics. But the principal spiritual heritage is his devotion to science, keenness, and patriotism.

In compiling this article biographic notes and recollections of Alikhanian’s contemporaries have been used.