Radiation of a system of isomer nuclei due to an electromagnetic transition with change of momentum J2–J1 and directly connected to exchange of a magnetic interaction was investigated. Such an interaction may be a magnetic exchange interaction of the Ruderman-Kittel or Sull-Nakamura type as well as any other type of interaction resulting in nuclear ferromagnetism at T<Tc. The initial state of the system is prepared by the quick cooling technique at T lower than Tc, the nuclear ferromagnetic temperature. It is shown that this initial state has a full symmetric wave function (which is the eigenfunction of the whole Hamiltonian as well as operators R2, Rz, J2,JZ) and the maximum value of the cooperation number. This method of initial state preparation in this range of frequencies replaces the π/2-impulse technique in optics. The superradiance intensity of the system from a waveguide is found, assuming |κ| = const for angles from zero to the Bragg angle.

Focusing properties and mechanisms are experimentally investigated of an intense pulsed light-ion beam or a medium-mass ion beam extracted from racetrack type magnetically insulated diodes. Quantitative determinations are made for three factors that affect the focusing ability of the beam, i.e., local divergence angle, deviation angle from ideal trajectory and space-charge effect. Behaviour of electrons in an anodecathode gap as well as neutralizing process of the ion beam by electrons are studied in connection with beam focusing. It is found that there is a close correlation between ion yield and electron irradiation on the anode. By adopting a perforated cathode instead of a vane cathode to ensure good uniformity of electric field in the accelerating gap, we have succeeded in significantly reducing the divergence angle. Several new diagnostic techniques and methods have been developed, yielding information such as the time-resolved trajectory and profile or incident angle of the beam. Electron temperature of the anode plasma is theoretically anticipated from the ions observed experimentally. From an estimate of beam divergence due to a space-charge effect, it is suggested that ‘breakeven’ can be achieved without using conventional z-discharged plasma channels if a bunch of boron beams is utilized.

Spectral structure of various half harmonic (ω0/2, 3ω0/2 and 5ω0/2) emission from an inhomogeneous plasma is analyzed. Several interaction mechanisms are studied and the effects of plasmon refraction and reflection are included in the analysis. These modify earlier results of the homogeneous plasma model considerably and increase the number of possible coupling configurations. The predictions of results in the different lasertarget experiments are discussed.

From the neodymium glass laser system Novette with two beams of 74 cm diameter and 18 kJ energy per pulse output in the nanosecond range, the design, the steps of the construction, and results of the system are reported. The two beams are synchronized to 5 psec and conversion to green light up to 78% has been realized. Conversion to four times the laser frequency is measured with more than 25% conversion. Simulation and measurement of laser beam properties at several locations permit an analysis to define the final Nova configuration. About half of Novette's experiments were to study short wave length laser–plasma interactions for the then better coupling by inverse bremsstrahlung mechanisms for inertial confinement fusion with laser intensities up to 1017 W/cm2. Experiments were divided between high density implosion research and non-local thermodynamic equilibrium plasma conditions.

A mechanism has been discussed before by Dragila and Hora where very short laser pulses in a homogeneous plasma can be absorbed without collisions by the action of time dependent nonlinear forces. The resulting absorption lengths are of interest for the study of femtosecond neodymium glass laser pulses or the sub-picosecond carbon dioxide laser pulses which are now available. A mathematically more rigorous treatment of this problem is presented where a nonlinear differential equation is derived for the general solution in the approximation of Klima and Petrzilka. The ordinary differential equation can be solved exactly. With reasonable initial conditions, the solutions are similar to those of Dragila and Hora and are evaluated numerically for cases of experimental interest.

The problems concerning the development of high f-number spectrographs with high spectral and spatial resolution using holographic reflecting gratings, for the study of processes of harmonic generation in laser plasmas are considered. The concave holographic gratings and spectrograph schemes used in the “Delfin-1” installation are described. The anomalous generation of ω0 and 2ω0 harmonics from the subcritical density plasma region has been observed experimentally. Possible interpretations of the observed effect are given.