RESUMEN
We present the design and parameters of a compact and mobile high-current pulse generator, which can be applied in the study of warm dense matter in university laboratories. The generator dimensions are 550 × 570 × 590 mm3, the weight is â¼70 kg, and it consists of four "bricks" connected in parallel. Each brick, made up of 2 × 40 nF, 100 kV low-inductance capacitors connected in parallel, has its own multi-gap and multichannel ball gas spark switch, triggered via a capacitively coupled triggering by a positive polarity pulse of â¼80 kV amplitude and â¼15 ns rise time. At a charging voltage of â¼70 kV, the generator produces a â¼155 kA current pulse with a rise time of â¼220 ns on a â¼15 nH inductive short-circuit load and a â¼90 kA amplitude current pulse in the underwater electrical explosion of a copper wire.
RESUMEN
A time- and space-resolved hard x-ray source was developed as a diagnostic tool for imaging underwater exploding wires. A ~4 ns width pulse of hard x-rays with energies of up to 100 keV was obtained from the discharge in a vacuum diode consisting of point-shaped tungsten electrodes. To improve contrast and image quality, an external pulsed magnetic field produced by Helmholtz coils was used. High resolution x-ray images of an underwater exploding wire were obtained using a sensitive x-ray CCD detector, and were compared to optical fast framing images. Future developments and application of this diagnostic technique are discussed.
RESUMEN
An analysis of the experimental data available and of the present theoretical concepts shows that even the initial physicochemical chemical precellular stages of biological evolution are impossible in the interstellar medium, while biomonomers possibly formed on asteroids and comets might have participated after transportation to the Earth in the final stages of the origin of the first precellular biological structures and then in the first living cells.