Gas-puff Z-pinch Device Research Articles

Experimental study of gas-puff z-pinch plasma

A small neon gas-puff z-pinch device was constructed, and the plasma implosion and its radiation characteristics were studied experimentally. The plasma implosion was investigated using a three-frame Mach–Zehnder interferometer (TFMZI) that is capable of taking three pictures (5 ns exposure and 13 ns interpicture delay) within a single z-pinch shot. Thermopiles were also used in the experiments with the TFMZI to study the correlation between the total energy of x-ray emission and the plasma implosion. The ion beams from the z-pinch plasma were analysed using a compact Thomson spectrometer. Based on the experiments, the imploding velocity and electron density of the plasma shell were obtained, a conclusion that a nearly uniform and symmetric imploding plasma shell would emit a higher x-ray yield than an asymmetric one was drawn and the charge state resolved energy spectra of ion beams emitted from the z-pinch plasma were plotted.

A three-frame Mach–Zehnder interferometer for measuring dense magnetized plasmas

A three-frame Mach–Zehnder interferometer (TFMZI) was developed for taking three pictures of the imploding plasma produced by one shot of fast pulsed discharge. TFMZI consists of a YAG laser, a beam splitter, and a Mach–Zehnder interferometer. By passing through the beam splitter the laser beam was split into three beams with an interbeam delay of 13 ns and each laser beam will give a snapshot of the implosion state. The measurements with the TFMZI were conducted on a small gas-puff z-pinch device and gave good results. In principle an upgraded four or (more) frame Mach–Zehnder interferometer could be constructed if much improvement was made on the TFMZI.

Soft X-ray spectroscopic study of a gas-puff Z-pinch argon plasma

X-ray radiation characteristics of argon plasma produced by a gas-puff Z-pinch device were investigated using an X-ray crystal spectrometer, an X-ray diode, and an extreme ultraviolet (XUV) spectrometer. Using a germanium crystal we have observed spectral emission from Ar XVII produced by hot spots at the pinched stage. With the help of a 2-m grazing incidence XUV spectrometer, the spectrum of 30 to 250 /spl Aring/ were obtained. Strong lines from Ar VIII to Ar XIII were observed with a continuum whose peak is around 120 /spl Aring/. The radiation energy in the spectral range is estimated to be about 23 joule which is about 0.6% of the electrical energy stored in capacitors.

2-D Code for Simulating a Hollow Gas Puff Z-Pinch

We compare the dynamics of plasma in a hollow gas puff Z-pinch device, obtained with Schlieren pictures, with the predictions of a 2-D MHD Lagrangian code. We show that agreement between the model and experiment require an axially variable line density and width of the injected gas.

Experimental study on the dynamics of a cylindrical plasma sheath in a gas-puff z-pinch device

The dynamics of a hollow cylindrical plasma sheath produced in a gas-puff Z-pinch device were studied with a differential interferometer. The velocity of the imploding plasma during three stages of compression the minimum radius of the pinched plasma column, the hot spots and the X-ray emissions were measured. The effect of the parameters of the gas cylinder on the plasma properties and X-ray emission was investigated with three different nozzles. Not only the gas density but also the distribution may influence the process of implosion. The experiments show that a thinner gas sheath produces a higher velocity of compression and higher X-ray yield. An interesting phenomenon of multiple pinch was observed. X-rays may be emitted at different locations and different instants.

Elemental imaging of biological specimens using a z pinch

A small scale (5 kJ stored electrical energy) gas puff z-pinch device has been used as an intense tunable flash x-ray source for high-resolution (15-nm spatial resolution) contact microscopy of unstained biological specimens. The selection of gas injected into the device to form the plasma determined the radiated spectrum. When the gas was varied, areas of different chemical composition within the specimens were selectively imaged.

An absolute measure of heating by suprathermal electrons in a gas puff Z-pinch

X-ray spectroscopy of high density (ne approximately=1021 cm-3) hot spots in an argon gas puff Z-pinch device has shown resolved K alpha -like transitions from various ionisation stages. An investigation into hot-spot physics suggests that collisional excitation by runaway electrons drives the inner shell emission. The intensity of the inner transitions provides a measure of the suprathermal electron energy deposition, which is sometimes greater than the energy content of a hot spot. However the authors argue that suprathermal electrons are not a principal heating source for the X-ray hot spots.