[en] It is shown that collisional suppression of Doppler broadening may occur in laser-generated plasmas even in the XUV spectral region because of the short ion mean free path due to the high emitter and mean ion charges. Numerical estimates are presented based on a collisional-radiative model of the ionisation in plasmas of varying atomic number. (author)

[en] The authors assembled a small theta pinch discharge equipment to carry out the experiments for clarifying the characteristics of theta pinch discharge. The discharge tube is made of Pyrex glass of 6.2 cm I.D. and 50 cm length, surrounded with a one-turn theta coil of 20 cm axial length and 8 cm I.D. The discharge tube is evacuated in advance down to the basic vacuum of 10^-5 Torr, then Ar gas is filled through a variable leak valve to an appropriate initial pressure. At the charging voltage of 20 kV and 25 kV and in the range of enclosing pressure of 11 to 125 m Torr, the experiments have been performed on the distribution of magnetic field, current density, electromagnetic force, and electric field intensity, and electrical conductivity and electron temperature. By the measurement of the electromagnetic field of theta pinch plasma generated by the discharge of charging energy 1900 J, the following conclusions were obtained. (1) In the magnetic field distribution for the theta pinch discharge generated by low energy, the phenomenon of counter magnetic field appeared, and pinch compression heating occured. (2) The complicated distribution of electric field in azimuthal direction was observed at the time of plasma generation, and detailed examination is required for the analysis of this distribution. (3) The results of conductivity and temperature calculations at the center portion of current layers showed the values of 648 mho/cm and 1.22 x 10⁵ K immediately before the arrival of the current layers at the center axis. (Wakatsuki, Y.)

[en] Controlled thermonuclear fusion research programs have received new impetus in most countries concerned by such activites, probably due to the achievements of the PLT machine at Princeton University. What efforts will be attributed today to promote industrial-scale development of thermonuclear fusion, which is not expected to become a reality until the 21st century. Why does the Tokamak technology, despite its complexity, have a greater chance of being adopted. A worldwide survey of the progress of scienfic endeavors in this field provides an answer to the latter question. France is playing a prominent role in Tokamak and laser fusion development and is granting substantial financial backing to increasingly expensive experimental projects. Ignition has been promised for the next decade. What work remains to be done to demonstrate fusion feasibility

[en] The effect of an intense gyrofrequency plasma turbulence of the population of Zeeman sublevels of the 1Ssub(1/2) states of HI atoms in a rarefied turbulent plasma located in the resonant field of radio (lambda=21 cm) or ultraviolet (lambda approximately 1216-912 A) radiation is considered theoretically. The spin temperatures of the magnetic sublevels are determined and it is shown that the conditions for production of inverse population of the indicated sublevels in the plasma appreciably differ from those mentioned in previous works. The damping (amplification) coefficient of the radio waves lambda=21 cm traversing the medium is found

No abstract available

No abstract available

[en] Because of the longer mean free path of high-energy ions, they will be preferentially lost from small pellets containing thermonuclear reactants. This effect has been calculated and, in the most extreme case calculated, a factor-of-about-four reduction of the reaction rate in DT from the Maxwell average rate at the same mean ion kinetic energy is found. (author)

[en] Developed is the nonlinear theory of regular vibration excitation by monoenergetic electron beam in the plasma cavity resonator with regard for desynchronizing effects between the excited field and the beam, and with regard for the field energy selection from the interaction region. It is shown that the desynchronizing between the field and the beam caUses the nonmonotonous dependence of the increment on the field amplitude. Found are the maximum values of this amplitude and calculated are the corresponding values of efficiency of the system considered as the damping function at various desynchronizing parameter values

[en] The dynamic form factor and the dispersion relation of the plasma oscillation of two-dimensional classical systems of electrons are obtained by numerical experiments in the domain 2.2 <= GAMMA = (πn)sup(1/2)e²/T<=71, n, e, and T being the number density, the electronic charge, and the temperature in energy units, respectively. (Auth.)

[en] Unique design techniques are needed for low activity ceramic materials in first wall/blanket regions of fusion reactors. A Weibull probabilistic design approach is used to characterize the scatter in the fracture strength and the size effect. Results indicate that ceramic first wall/blanket structures should be modular and each module should be proof tested. The ceramic materials should have high fracture strength, high Weibull modulus, and minimal strength degradation due to subcritical crack growth. The Weibull statistical analysis is coupled with finite element thermal and stress analysis and the probability of failure of ceramic first wall/blanket design concepts is predicted. The usefulness of the approach is demonstrated by optimizing the geometry of the structure to produce minimum probability of failure. (Auth.)