9 research outputs found
Effect of incoming radiation on the non-LTE spectrum of Xe at Te = 100 eV
The effect of a diluted Planckian radiation field on a Xe gas at the electron
temperature of 100 eV is investigated within the framework of a Collisional
Radiative Model, using the HULLAC code. The atomic model spans 19 charge
states, includes 20 375 configurations and contains more than 2 10^6 levels. We
have simulated detailed spectra comprising more than 10^9 transitions with the
Mixed UTA model. The radiation temperature Tr is varied from 0 to 1.5 Te. The
dilution factor, D, applied to decrease the radiation field, is varied
independently from 0 to 3 at fixed Tr = Te. In both cases, the average charge
state Z* increases from 15 to 27, but in different ways. It is shown that even
a dilution D = 0.01 changes Z* by more than 1.5. Different combinations of Tr
and D yielding exactly the same Z*, may give line ratios sufficiently different
to be observed. This fact is explained by the interplay of the shape of the
radiation field and the atomic structure
Edmond Locard (1877-1966), la criminalistique moderne (suivi d'un récit inédit du Dr Locard " Voyage au USA d'avril à juillet 1918 pour la Croix-Rouge américaine")
LYON1-BU Santé (693882101) / SudocPARIS-BIUM (751062103) / SudocPARIS-Académie Médecine (751065201) / SudocPARIS-Bib. Serv.Santé Armées (751055204) / SudocSudocFranceF
Malaria in French Guiana Linked to Illegal Gold Mining
International audienceno abstrac
Dynamic X-ray diffraction observation of shocked solid iron up to 170 GPa
Investigation of the iron phase diagram under high pressure and temperature is crucial for the determination of the composition of the cores of rocky planets and for better understanding the generation of planetary magnetic fields. Here we present X-ray diffraction results from laser-driven shock-compressed single-crystal and polycrystalline iron, indicating the presence of solid hexagonal close-packed iron up to pressure of at least 170 GPa along the principal Hugoniot, corresponding to a temperature of 4,150 K. This is confirmed by the agreement between the pressure obtained from the measurement of the iron volume in the sample and the inferred shock strength from velocimetry deductions. Results presented in this study are of the first importance regarding pure Fe phase diagram probed under dynamic compression and can be applied to study conditions that are relevant to Earth and super-Earth cores
The European Astrobiology Institute
The European Astrobiology Institute (EAI) will be a consortium of European research and higher education institutions and organisations as well as other stakeholders aiming to carry out research, training, outreach and dissemination activities in astrobiology in a comprehensive and coordinated manner and thereby securing a leading role of the European Research Area in the field
Progress in warm dense matter study with applications to planetology
We present an overview of some recent theoretical and experimental results obtained on the properties of iron and silica at conditions encountered in planetary interiors. The first part is concerned with the development of x-ray absorption near edge spectroscopy in dynamical experiments using high-energy lasers as a tool to investigate phase transitions and structural changes at extreme pressure-temperature conditions for these two key constituents. The second part focuses on the development of a quasi-isentropic compression technique to achieve the pressure-temperature conditions anticipated in planetary interiors (3-10 Mbar, 5000-8000 K). The experiments were performed using the LULI, LLNL and LIL high-energy lasers' facilities. The experimental results are analyzed using first-principle simulations based on density functional theory