The $Z$-pinch dynamic hohlraum is an x-ray source for high energy-density physics studies that is heated by a radiating shock to radiation temperatures $>200\mathrm{eV}$. The time-dependent 300–400 eV electron temperature and $15–35\mathrm{mg}/\mathrm{cc}$ density of this shock have been measured for the first time using space-resolved Si tracer spectroscopy. The shock x-ray emission is inferred from these measurements to exceed 50 TW, delivering $>180\mathrm{kJ}$ to the hohlraum.

The results of recent experimental and numerical studies of nanosecond high-voltage discharges in pressurized gases are reviewed. The discharges were ignited in a diode filled by different gases within a wide range of pressures by an applied pulsed voltage or by a laser pulse in the gas-filled charged resonant microwave cavity. Fast-framing imaging of light emission, optical emission spectroscopy, x-ray foil spectrometry and coherent anti-Stokes Raman scattering were used to study temporal and spatial evolution of the discharge plasma density and temperature, energy distribution function of runaway electrons and dynamics of the electric field in the plasma channel. The results obtained allow a deeper understanding of discharge dynamical properties in the nanosecond timescale, which is important for various applications of these types of discharges in pressurized gases.

An approach for measurements of magnetic fields, based on the comparison of the magnetic-field-induced contributions to the line shapes of different fine-structure components of an atomic multiplet, is proposed and experimentally demonstrated. Contrary to the methods based on detecting an anisotropy in either the emitted radiation or in the dispersion properties of the medium, the present method is applicable when the field direction or amplitude vary significantly in the region viewed or during the time of observation. The technique can be used even when the line shapes are Stark or Doppler dominated. It has potential applications in laser-matter interactions, plasmas driven by high-current pulses, and astrophysics.