Many laser produced plasmas contain ions with different charge-to-mass ratios (Z₁/M₁≠Z₂/M₂). We study here the free expansion into a vacuum of a multi-ion species plasma with both single and two elecron temperatures. Numerical solutions for CH₂ and SiO₂ targets are obtained. Analytic asymptotic solutions are obtained for some limiting cases using perturbation analysis. These numerical and asymptotic solutions are compared with experimental fast ion spectra. It is shown that from the ion velocity spectrum important plasma parameters such as the absolute hot-and cold-electron temperatures, the hot-to cold electron temperature ratio, and the hot-to cold electron density ratio can be estimated. The energy loss associated with the fast ion is also estimated.

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A thermoplastic device, which used corona wires with grids to aim at a uniform charging over the surface of a thermoplastic and a sheet couple to make a temperature measurement for the purpose of stopping heat at a optimum developing time, is described. This device made it easy to construct a matched filtering system with a quasi real-time input element. The diffraction efficiency of the thermoplastic as a function of signal intensity with a parameter of reference beam intensity was measured. This result suggested a easier method of making a matched filter than using a photographic material. With a BSO device, a matched filtering system was constructed and a matched filtering for character reading was carried out.

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We have investigated the operational parameters of a passively mode-locked Rh-6G dye laser, having a cavity with five mirrors and two jet streams, in order to generate stable subpicosecond pulses. The optimum concentration of saturable absorber (DODCI) was found to be 6.0×10^-6M. The ratio of pumping power P_p to the threshold power P_th (P_p/P_th) falls in a range of 1.08±0.01, in order to obtain good mode-locking. The optimum value P_p/P_th is independent of the DODCI concentrations. Under this optimum condition, the narrowest pulses of 0.69ps were generated at 614nm. The time-bandwidth product of the pulse was calculated to be 0.78 indicating that the pulse was close to being transform-limited. The lasing-wavelength was tunable in the range of 604-613nm by using a Lyot filter. A nearly transform-limited pulse of 1.54ps with the time-bandwidth product of 0.40was obtained at 605.5nm.

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The amplification enhancement of free electron lasers by a co-propagating microwave is investigated. for single mode amplification. Coupled equations for the particle motions and the radiation amplitude are solved numerically in the co-propagating microwave. As the result, it is found that the microwave enforces untrapped electrons to be resonant, and retrapped in a ponderomotive potential. Therefore, the microwave field can be high without detrapping compared with D. C. field and/or equivalent wiggler tapering, and the amplification rate is found to be enhanced significantly.

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This paper is concerned with experimental reconstruction of images by a simple X-ray CT apparatus. The experimental apparatus consists of an X-ray source, an ITV camera with intensity display and a personal computer. Several CT software programs are made appropriately for the personal computer. Image reconstruction is experimentally obtained. The discussion is also given to our scheme of constructing a CT system for laser-fusion diagnostics.

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