The diffraction method is used to study the properties of laser radiation interacting with a gas-cluster plasma. Based on the simulation of propagation a laser beam with a wavelength 800 nm through a ...hexagon Cu-mesh and subsequently compared with the obtained experimental diffraction pattern, the contribution of the second harmonic to the laser radiation was considered. The capability of this method to reveal the spectral composition of laser radiation is discussed. Also, the dependence of the visibility of the diffraction pattern on the intensity of the laser beam is considered. Besides, the contribution of x-ray radiation generated from the laser-cluster interaction into the observed diffraction pattern signal was estimated.
The investigation of a recombining laser plasma is topical primarily because it can be used to simulate the interaction between plasma jets in astrophysical objects. It has been shown that the ...relative intensities of transitions of a resonance series of He-like multicharged ions can be used for the diagnostics of the recombining plasma. It has been found that the intensities of the indicated transitions for ions with the nuclear charge number
Z
n
~ 10 are sensitive to the plasma density in the range
N
e
~ 10
16
–10
20
cm
–3
at temperatures of 10–100 eV. The calculations performed for the F VIII ion have determined the parameters of plasma jets created at the ELFIE nanosecond laser facility (Ecole Polytechnique, France) in order to simulate astrophysical phenomena. The resulting universal calculation dependences can be used to diagnose different recombining plasmas containing helium-like fluorine ions.
An x-ray radiography technique based upon phase contrast imaging using a lithium fluoride detector has been demonstrated for goals of high energy density physics experiments. Based on the simulation ...of propagation an x-ray free-electron laser beam through a test-object, the visibility of phase-contrast image depending on an object-detector distance was investigated. Additionally, the metrological capabilities of a lithium fluoride crystal as a detector were demonstrated.
Study of warm dense matter remains a very important task for understanding of many unique phenomena observing as in astrophysical research as in inertial fusion and fast ignition. In this work, we ...studied the parameters of plasma created by 1.7 ps laser pulses of relativistic intensity of 7 × 1018 W/cm2 in a specially designed Al-Cu wire-shape target, in comparison with a flat Cu and Al foil targets. We observed the strong emission of neutral or virtually neutral Cu Kα line from both Cu foil and Cu wire part of targets, which indicates the creation of a dense state exposed to the intense flow of hot electrons. Parameters of the plasma were evaluated by comparison of experimental spectra with the results of modeling by collisional-radiative kinetic code PrismSpec under the plasma zone approach. The using of Al foil in front of Cu wire part of target allowed avoiding the direct heating of Cu-wire and acquiring spectra of Cu K-shell emission evidently belonging to emission of warm dense matter (WDM) state. The upper estimate for the electron temperature in WDM region was found to be below 80 eV.
A review of studies on the X-pinch as a radiation source for X-ray projection shadow radiography (XPSR) and X-ray absorption spectroscopy (XAS) is presented. The ultimate capabilities of the ...techniques and ways of their achievement are considered. XPSR has been successfully used to study high-energy-density plasma objects, in particular, exploding wires and wire arrays. Using XPSR, the internal structure and dynamics of a wire explosion and wire array implosion have been investigated for the first time, which has made it possible to develop an adequate consistent theory of the processes occurring in the wire loads of generators with currents from several units of kiloamperes to a few tens of megamperes. The use of XAS for diagnostics of wire loads has allowed one for the first time to measure the parameters of matter in the wire core and plasma corona of the load. X-ray images of various biological objects have obtained, including those with the use of the phase contrast method. This review is a logical continuation of the review “Х-Pinch” Plasma Phys. Rep. 41, 319, 493 (2015), in which the Х-pinch as a physical object was considered.