Diagnostics of a magnetic field by X-ray polarization spectroscopy

A new method of diagnostics of a magnetic field of a Z pinch, based on the use of three instruments for x-ray spectropolarimetry, is suggested.     

The 5v 3 bands of 18O enriched ozone: line positions of 16O16O18O, 16O18O16O, 16O18O18O and 18O16O18O

The four 5v ₃ bands of ¹⁸O enriched ozone have been observed and analysed for the first time. Two species (¹⁶O¹⁸O¹⁶O and ¹⁸O¹⁶O¹⁸O) belong to the C_2v symmetry group and two other (¹⁸O¹⁸O¹⁶O and ¹⁶O¹⁶O¹⁸O) to the C_s symmetry group. They have been recorded at a resolution of 0.008 cm^?1 with a pathlength of 32.16 m. Despite the very weak absorptions observed, almost 250 energy levels have been derived for each of the 4 species, with J ? 35 and K _a ? 13, and suitable sets of Hamiltonian parameters have been determined. For 3 species it has been necessary to account for the resonance between the (005) and (311) states to correctly reproduce the spectra observed. These resonances, anharmonic for C_2v, and hybrid (both anhar-monic and Coriolis) for C_s symmetry confirm the accidentally extremely strong coupling between the (005) and (311) states for ¹⁶O₃, due in that case to the very close distance between unperturbed energy levels. This work also confirms the excellent prediction of band centres of these four species derived from the recently determined isotopically invariant molecular potential function.     

Measurement of temperature, density, and particle transport with localized dopants in wire-array Z pinches

Axially localized NaF dopants are coated onto Al cylindrical wire arrays in order to act as spectroscopic tracers in the stagnated z-pinch plasma. Non-local-thermodynamic-equilibrium kinetic models fit to Na K-shell lines provide an independent measurement of the density and temperature that is consistent with spectroscopic analysis of K-shell emissions from Al and an alloyed Mg dopant. Axial transport of the Na dopant is observed, enabling quantitative study of instabilities in dense z-pinch plasmas.     

Data Acquisition and Diagnostic System for Prototype of PANDA Pellet Target

Physics of Atomic Nuclei - In the PANDA experiment of the FAIR project, it is proposed to use internal targets based on the hydrogen isotopes that provide a monodisperse regime of flow generation...     

Beam Dynamics Simulation for the Plasma Investigation on the Experimental Facility HIPr-1

Physics of Atomic Nuclei - The HIPr-1 (Heavy-Ion Prototype) beam transport channel was designed for performing experiments to measure the energy losses in plasma, which was developed considering...     

WADM and radiation MHD simulations of compact multi-planar and cylindrical wire arrays at 1 MA currents

The radiative performance of Z-pinches created by the imploding wire array loads is defined by the ablation and implosion dynamics of these loads. Both these processes can be effectively modeled by the Wire Ablation Dynamics Model (WADM), which extends the formalism exploited earlier for the cylindrical wire arrays to the loads of arbitrary geometries. The WADM calculates the ablation rates for each array wire and provides the important dynamic parameters, such as the specific mass and velocity of the imploding plasma, which can be used to estimate the shapes of the x-ray pre-pulse and, partially, the main x-ray burst. The applications of the WADM also extend to combined material wire array loads. The ablation and implosion dynamics of novel Prism Planar Wire Array (PPWA) and combined material (Mo/Al/Mo) Triple Planar Wire Array (TPWA) loads are discussed in detail. The combined WADM and radiation MHD simulation is applied to model the radiative performance of the precursor plasma column, created by the imploding stainless steel compact cylindrical wire array. As the radiation effects intensify with the mass accumulation at the array center, the simulation reveals the transformation of quasi-uniform precursor column into a heterogeneous plasma structure with strong density and temperature gradients. We find that radiative performance of the precursor plasma is greatly affected by the load geometry as well as by the wire material.     

Study of the Z-Pinch Plasma Initiated by the Electron Beam

A lot of activities are carried out to develop compact laser accelerators. The transportation and focusing of beams in Z-pinch-type discharges, which requires thorough investigations into methods for the formation of these discharges, are important problems to be solved. At the ITEP, an experimental setup [1] is constructed to study Z-pinch plasma dynamics when the discharge is initiated by an electron beam. The first results of the experimental and numerical investigations show that development of the discharge initiated by an electron beam differs considerably from the ordinary Z-pinch formation process.