The results of ID-ERA and 2D-TIGR, OMEGA codes calculations of compression and burn of indirect-driven targets for the thermonuclear ignition and Engineering Test Facility are presented. The possibility to obtain high-energy yield of G > 100 with driver energy of Ed = 5−10 MJ by using the heavy-ion one-beam accelerator as the main driver and powerful laser for fast ignition of thermonuclear detonation of cylindrical targets is pointed out.

A review of the AVLIS (atomic vapor laser isotope separation) development performed by GPI and LAD Ltd. (Moscow, Russia) during the last 4–5 years is presented. The processes of laser isotope separation of ytterbium (Yb) have been studied analytically, with numerical simulations, and experimentally. The basic attention is given to the following topics: the selectivity of ionization; the laser beams arrangement in a cavity; the forming of a vapor flux; and the extraction of ions from plasma. Installations to produce highly enriched 168Yb in industrial scales were created. The content of 168Yb in the laser-produced plasma reached 90–95%, in the material deposited on the ion collector up to 62%, and in the washing liquid up to 45%. The rate of the enriched Yb production was up to 5–10 mg/h. For the first time a profitable commodity was produced by the AVLIS method.

A mechanism of trapping and entrainment of electromagnetic (EM) field pulses into supercritical regions of an inhomogeneous plasma by ion-acoustic waves is considered.

Free-electron lasers exploiting media with periodically modulated refractive indices are studied. The regime of large modulation is considered, and the conditions of its realization are discussed. Two types of media with periodically modulated refractive indices are analyzed: a gas-plasma medium with a periodically varying degree of ionization and a superlattice-like medium. The gain, saturation field, and efficiency of these free-electron lasers are found. For any given frequency, the gain is optimized with respect to the choice of electron energy, direction of motion, and other parameters. Its relationship with other types of free-electron lasers (e.g., the Cherenkov laser) is discussed.

A density-matrix approach is under development for the investigation of the angular distribution and polarization of atomic radiative emissions in crossed quasi-static electric and magnetic fields. Particular interest has centered on applications to spectroscopic observations in the intense fields of the high-power light-ion inertial fusion device PBFA II at Sandia National Laboratories, and to magnetic field measurements in tokamak plasmas. Noteworthy features of our general density-matrix analysis include allowances for the mixing of both the bound and continuum field-free atomic eigenstates in an arbitrary arrangement of electric and magnetic fields, and for the possible coherent excitation of the nearly degenerate field-dependent atomic substates that produce the overlapping Stark-Zeeman components. The influence of directed collisional excitation may also be taken into account. From the angular-momentum selection rules, specific results have been obtained for observation of polarized radiative emissions in the direction of the magnetic field.

The Heavy-Ion Fusion Systems Assessment project is nearing completion of a two-year effort. The resulting system modelwill be used to set directions for future target design work.

Major uncertainties in target design were studied using thecost of electricity as a figure of merit. Net electric power was fixed at 1000 MW to eliminate large effects due to economies of scale. The system is relatively insensitive to target gain, factors of three changes in gain resulting in 8 to 12% changes in electricity cost. Possible increased peak power requirements pose only a small cost risk, but require many more beamlets for transport. A shortening ofthe required ion range causes both cost and beamlet difficulties. A factor of 4 decrease in the required range at a fixed driver energy increases electricity cost by 44% and raises the number of beamlets to 240. Finally, the heavy ion fusion system can accommodate large increases in target costs. Thus, to address the major uncertainties, target design should concentrate on requirements for ion range andpeak driver power.

When viewed from outer space, the earth's magnetic field does not resemble a simple dipole, but is severely distorted into a comet-shaped configuration by the continuous flow of solar wind plasma. A complicated system of currents flows within this distorted magnetic field configuration called the ‘magnetosphere’ (See figure 1). For example, the compression of the geomagnetic field by the solar wind on the dayside of the earth is associated with a large-scale current flowing across the geomagnetic field lines, called the ‘Chapman-Ferraro’ or magnetopause current. The magnetospheric system includes large-scale currents that flow in the ‘tail’, the ring current that flows at high altitudes around the equator of the earth, field-aligned ‘Birkeland’ currents that flow along geomagnetic field lines into and away from the two auroral regions, and a complex system of currents that flows completely within the layers of the ionosphere, the earth's ionized atmosphere. The intensities of these various currents reach millions of amperes and are closely related to solar activity. The geomagnetic field lines can also oscillate, like giant vibrating strings, at specified resonant frequencies. The effects of these vibrations, sometimes described as ‘standing Alfvén waves’, have been observed on the ground in magnetic field recordings dating back to the beginning of the century. Observations of currents and waves with satellite-borne magnetic field experiments have provided a new perspective on the complicated plasma processes that occur in the magnetosphere. Some of the new observations are described here.

A method of probing beam refraction is suggested for the investigation of laserproduced plasma with high density gradients. The refraction angle α of a probing ray as a function of ray impact parameter p is used as input data. Different experimental realizations of α(p) measurements are considered. Results from laser produced plasma interferograms processed with phase shift and refractometry methods are compared.

Energetic electrons, with energy from many tens to several hundred keV can be generated in laser produced plasmas by such laser plasma instabilities as the 2ωp instability, which occurs at the quarter critical density. It is important to know not only how these are produced, but also how they are transported and deposit their energy in the interior and whether they preheat the fuel. We introduce the velocity dependent Krook approach to this problem, and compare it to other approaches that have appeared in the literature as regards accuracy and economy of incorporating in a fluid simulation. This velocity dependent Krook technique is reasonably accurate and reasonably simple and economical to incorporate into a fluid simulation.

A method of absolutely unfolding the atomic spectrum by a pinhole transmission grating spectrometer (TGS) is discussed in detail. The numerical process considers both the factors of higher-dispersive-order overlapping of TGS and source-size widening effects. Real soft-X-ray spectra of aluminum, copper, and gold plasmas are presented of experiments performed on the Six-Beam Laser Facility at the Shanghai Institute of Optics and Fine Mechanics.

The main tool for the laser plasma work at MPQ (Max-Planck-Institut für Quantenoptik) is the ASTERIX iodine laser delivering 300 J/300 ps pulses at 1·3 m, operational also at 2ω and 3ω. A fifth 30-cm diameter am lifier is under construction to increase the pulse energy up to 2 kJ.

Soft X-ray radiation emitted by laser plasmas and its influence on energy transport and hydrodynamics is studied. Time and space resolved spectroscopic measurements of soft X-radiation from a variety of targets are compared with analytical models and computer results. Planck radiation is produced in gold cavities to study radiation hydrodynamics. Theoretical work comprises shock waves in solids, the electronic structure of very high density matter, radiation pumped X-ray laser and development of the appropriate computer codes.

Estimates indicate that dense plasmas with temperatures of several ten keV can be produced with the heavy ion accelerator now under construction at GSI-Darmstadt. Experiments are being prepared to be started in 1991. Measurements at the present UNILAC-accelerator confirm the theoretical prediction that the energy loss of heavy ions in a plasma is much higher than in cold matter.

We present a Ramsey technique using high-order harmonics for high-resolution atomic spectroscopy in the extreme ultraviolet. Pairs of time-delayed and phase-coherent harmonic pulses generated by the interaction of ultrashort and intense laser pulses with a noble gas are used to study excited states of krypton.

An effective theory of laser–plasma-based particle acceleration is presented. Here we treated the plasma as a continuous medium with an index of refraction nm in which a single electron propagates. Because of the simplicity of this model, we did not perform particle-in-cell (PIC) simulations in order to study the properties of the electron acceleration. We studied the properties of the electron motion due to the Lorentz force and the relativistic equations of motion were numerically solved and analyzed. We compared our results with PIC simulations and experimental data.

A numerical model for opacity calculations by using a family of analytical potentials for each configuration in the plasma is presented. The obtained numerical opacity results with this model are compared with those obtained by using a self-consistent potential model.

Inertial confinement fusion (ICF) has developed remarkably in the last 30 years. In the 21st century, we can expect fusion energy for civilian use. After the cold war era, the value of ICF has shifted from defense demands to peaceful applications. The megajoule laser systems are under construction expecting the development of spark ignition. However there are many problems to solve in science and technology. One alternative way is to use a petawatt short-pulse laser aiming for fast ignition. On the way to the final goal, we would like to contribute for various applications of high power lasers such as laboratory astrophysics, X-ray lasers, laser-induced lightning as well as laser processing.

Tritium self-heats at a rate of 97 W/mole because of its β activity. This energy drives preferential sublimation of solid T2 or DT from regions where a layer is thicker and warmer to regions where the layer is thinner and colder. A frozen tritium layer inside an isothermal container approaches isotropy exponentially with a time constant as short as 14.4 minutes. Targets Isotropized by Radioactively Induced Sublimation (IRIS) and sized for an ICF reactor demonstrate high gain and offer real fabrication advantages.

A new inverse Compton scattering scheme for production of high-energy Gamma-ray sources is proposed in which a Giga-electronvolt (GeV) electron beam is injected into a thermal hohlraum. It is found that by increasing the hohlraum background temperature, the scattered photons experience kinematic pileup, resulting in more monochromatic spectrum and smaller scattering angle. When a relativistic electron beam with energy 1 GeV and charge 10nC is injected into a 0.5 keV hohlraum, 80% of the scattered photons have energy above 0.5 GeV.