High-power Lasers and Laser Thermonuclear Fusion

Why do we need laser thermonuclear fusion?

As energy consumption has been growing since the beginning of the civilization, the humankind has to face energy challenges systematically. Until recently, these problems could be solved by discovering new energy resources. The oncoming depletion of traditional fossil fuels and tightening of environmental requirements on functioning of energy systems opens a brand new stage in energetic development of XXI century. This is because the level of emissions and waste by production of electricity has risen so much that it affects badly the whole ecosystem.

Not only because fuel resources are getting depleted, but as our understanding of good quality of life is changing over time, energy problems will becoming more and more important even in the medium term. Therefore, ecology of energy production is becoming one of the most significant factors.

To provide stable society development, it is necessary to develop energetics that uses almost unlimited resource and is safe to operate and non-polluting. Among given opportunities, thermonuclear energetics meets such requirements most sufficiently. Use of controlled thermonuclear fusion is related to several advantages: the highest among those known to humankind calorific value of equimolar DT-mixture (~ 3,4∙1014 J/kg), almost unlimited natural resources of deuterium (8 times higher than these of uranium) and more than 100 times lower levels of radioactive emissions when compared to energy cycles based on actinide fission reaction.

The possibility of using reactions of light nucleus fusion in creating non-polluting, safe and economically profitable energetics was mentioned for the first time more than 50 years ago. Inventions having been created since that time on can be divided into two groups: 1) systems based on magnetic confinement of hot plasma (tokamaks, stellarators); 2) pulse systems (systems of inertial thermonuclear fusion). Both systems are on the edge of creating experimental devices with positive power output that will test major elements of future thermonuclear reactors.

But how do high-power lasers fit?


Currently several types of drivers are being designed for inertial thermonuclear fusion: lasers, heavy ion beams, fast Z pinches. Advantages laser radiation has in solving of inertial thermonuclear fusion problem is that it can be relatively easily transported to a target and focused on it and also gives a possibility of producing great power density that is necessary for target effective pinch and heating.

Consistent development of both theoretical and practical works in the field of laser thermonuclear fusion (LTF) is currently observed in the USA, Europe, Russia, China, Japan. Russia has accumulated great experience and scientific potential in the field of LTF. The hot demand for it in the international scientific community is based on the achievements and original works of Russian scientists that are carried out in major scientific centers with significant experimental base. Such centers are LPI RAS, GPI RAS, NRNU MEPhI (Moscow), RFNC-VNIIEF (Sarov), RFNC- VNIITF (Snezhinsk), SRC TRINITI (Troitsk) and others.

High-power pulse lasers created for performing controlled thermonuclear fusion offer a unique opportunity to generate light pulses with megajoule energy range and power of hundreds of terawatt. By affecting condensed media with such pulses, it is possible to produced record-breaking local energy densities that cannot be produced in laboratory experiments by any other means.

In the USA the laser facility NIF (National Ignition Facility) with laser energy of 1,8 MJ that is concentrated in 192 laser radiation beams was commissioned in 2009; the high-power facility LMJ (Laser Megajoule) with laser energy of 1,8 MJ is putting into operation in France. In 2012 Russia started the process of creating its own laser facility of megajoule energy level.

Physics of interaction between laser radiation and matter is going through a phase of intense development. This is because the technology of generation of ultra-high intensity laser pulses in various wavelength ranges is developing rapidly.

Leading world-known laser centers have put into operation petawatt laser systems able to generate radiation pulses of 10-100 femtoseconds duration and 1019-1022W/sm2 peak intensity in focus.

International projects for creating laser multipetawatt and exawatt facilities are discussed actively (for instance, Extreme Light Infrastructure (ELI) in Europe, as well as its analogues in Great Britain, Japan, China).

Department and its significant features

The “Laser Thermonuclear Fusion Physics” Department №69 was created in 2011 for training specialists in the field of laser thermonuclear fusion physics, interaction of high-power laser radiation with matter, designing high-power lasers of nano-, pico- and femtosecond pulse duration.

Head of Department is the RAS academician, general design engineer of laser systems, Head of The Institute of Laser Physics (ILFI) RFNC-VNIIEF, Dr. Sci. in Physics and Mathematics, professor Sergey G. Garanin.

The training courses of the Department are given by qualified teachers. The specialists with high citation index that are well-known experts in their field are lecturing professional subjects. Several additional courses provides for online lecturing of certain sections by leading industry professionals. Master’s course programme includes such courses, as “Nonlinear optics”, “laser thermonuclear fusion physics”, “Interaction between laser radiation and matter”, “Methods of designing laser systems” and others. Therefore, various themes for students’ training and internship are given thus letting each student to fulfil their potential in the most interesting field of knowledge.

Students’ internship takes place in laboratory bases of NRNU MEPhI, Prokhorov General Physics Institute of the Russian Academy of Sciences (GPI RAS), Institute of Laser Physics (ILFI) RFNC-VNIIEF. Besides, students are employed in other scientific organizations of Rosatom and RAS (All-Russia Research Institute of Automatics named after N.L. Dukhov (VNIIA), LPI RAS and others). Professional activity of graduated students includes experimental research and computer modeling in such promising areas of modern physics, as high-power lasers, laser plasma physics and laser thermonuclear fusion. Under- and postgraduate students participate actively in organizing scientific schools and conferences.