Bremsstrahlung X-ray Emission Research Articles

Evidence of suprathermal electron fluxes in laser-produced plasma from the polarization and anisotropy of X-ray bremsstrahlung emission

Polarization and angular distribution of suprathermal X-ray emission from plasma produced by picosecond ruby laser pulses have been measured. Polarization of 12 ± 3 percent and anisotropy of X-ray angular distribution evidence the existence of suprathermal electron fluxes in plasma. Their direction corresponds to resonance absorption mechanism.

Resonances and Many-Body Effects in Electron Impact Excited Soft X-Ray Spectra

We present a brief review of variations of bremsstrahlung and characteristic soft X-ray emission yields near core level excitation thresholds in metallic La (4f-metals) and the 3d-metals treated by the author in collaboration with Wendin. We extend the discussion in this paper to include processes neglected in the above mentioned earlier work, the emphases being laid on the relative importance of resonant bremsstrahlung (fluorescence) versus characteristic emission and the importance of localised states versus extended states, for different core level excitation thresholds.

Interaction between emission-line filaments and highly energetic explosions in QSOs

The conditions under which QSO line-emitting regions can survive a relativistic explosion are investigated along with the question of whether past and future observations can place constraints on both predicted highly energetic outbursts of ultrarelativistic plasma or LF electromagnetic radiation and the line-emitting gas. Observed properties of QSO emission-line regions are reviewed, and the interaction between a relativistic explosion and a dense cloud is analyzed for the cases of a sudden release of relativistic plasma and an outburst of LF electromagnetic waves. Bremsstrahlung X-ray emission from shocked QSO filaments is calculated, the evolution of dense QSO clouds is examined, and radiative acceleration is excluded as the process responsible for the high bulk velocities of filaments, at least in sources that display energetic outbursts. An alternative mechanism involving highly energetic explosions is proposed.

Thermal and non-thermal X-ray bremsstrahlung emission from a high-temperature plasma

The results of calculations are presented which are of interest in the interpretation of X-ray temperature measurements of a laser-produced plasma. Emission from non-thermal electrons has been interpreted using a restricted class of electron distribution functions. The results of these calculations have been compared with published experimental results and the proportion and energy of the non-thermal component has been estimated.

Features of Jupiter's Trapped Particle Environment Associated with Jovian Satellites?Pioneer 10 Results and X-ray Observations

Summary Following a brief summary of the relevant details of the Pioneer 10 mission to Jupiter, theoretical considerations regarding the absorption of trapped particles by Jupiter's inner satellites are reviewed. A comparison of the features predicted by theory with relevant Pioneer 10 results reveals remarkably good qualitative agreement in most cases. The Pioneer 10 data also show evidence of particle injection near lo which was predicted by a plasma sheath model of the interaction of lo with the surrounding magnetosphere of Jupiter. Estimates of the bremsstrahlung X-ray emission expected from the impact of the absorbed particles on Jupiter's satellites fall some seven orders of magnitude below current upper limits for X-ray emission from Jupiter, observed in Earth orbit. This implies that the observation of such X-rays to obtain the intensity and energy spectrum of the impacting particles will have to be done from much nearer the source, for example from a Jupiter orbiter outside the intense portions of the particle radiation belts.