The quotidian equation of state (QEOS) is a general-purpose equation of state model for use in hydrodynamic simulation of high-pressure phenomena. Electronic properties are obtained from a modified Thomas–Fermi statistical model, while ion thermal motion is described by a multiphase equation of state combining Debye, Grüneisen, Lindemann, and fluid-scaling laws. The theory gives smooth and usable predictions for ionization state, pressure, energy, entropy, and Helmholtz free energy. When necessary, the results may be modified by a temperature-dependent pressure multiplier which greatly extends the class of materials that can be treated with reasonable accuracy. In this paper a comprehensive evaluation of the resulting thermodynamic data is given including comparison with other theories and shock-wave data.

An electron conductivity model for dense plasmas is described which gives a consistent and complete set of transport coefficients including not only electrical conductivity and thermal conductivity, but also thermoelectric power, and Hall, Nernst, Ettinghausen, and Leduc–Righi coefficients. The model is useful for simulating plasma experiments with strong magnetic fields. The coefficients apply over a wide range of plasma temperature and density and are expressed in a computationally simple form. Different formulas are used for the electron relaxation time in plasma, liquid, and solid phases. Comparisons with recent calculations and available experimental measurement show the model gives results which are sufficiently accurate for many practical applications.

The resistivity of nearly solid-density Al was measured as a function of temperature over 4 orders of magnitude above ambient by observing the self-reflection of an intense, <0.5 psec, 308-nm light pulse incident on a planar Al target. As an increasing function of electron temperature, the resistivity is observed initially to increase, reach a maximum which is relatively constant over an extended temperature range, and then decrease at the highest temperatures. The broad maximum is interpreted as "resistivity saturation," a condition in which the mean free path of the conduction electrons reaches a minimum value as a function of temperature, regardless of the extent of any further disorder in the material.PACS numbers: 72.15.Cz, 52.25.Fi, 78.47.+p We report the first experimental study of the electrical resistivity of a solid-density material, in this case a simple Drude metal, over an extended range (4 orders of magnitude) of elevated temperature with little or no change in its density. The results show three general regions of the dependence of the resistivity on the temperature: Initially, the resistivity increases with increasing temperatures, reaching a relatively constant value that extends over a wide temperature range, and then it decreases as the temperature is further increased. We argue that these regions reflect differing mechanisms controlling the mean free path of the conduction electrons in different temperature ranges. In particular, the region of maximum resistivity is a result of "resistivity saturation," a condition in which the electron mean free path reaches a minimum value, independent of the degree of material disorder.The ability to study the resistivity of a well characterized solid-density material over a great range of elevated temperatures was made possible here by the use of ultrashort (<0.5 psec), relatively high-energy (0-5 mJ) laser pulses. The self-reflection of a laser pulse, focused onto a smooth target at fixed pulsewidth and spot size, was monitored over 4 orders of magnitude in energy. Frequency shifts of the reflected light were also recorded, and as discussed in detail below, these frequency shifts are shown to arise directly from the expansion velocity of the solid-vacuum interface. From the dependence of the interface velocity upon the laser intensity, we were able to determine the electron temperature and degree of interface expansion for each recorded value of the reflectivity. This information is sufficient to determine the resistivity of solid-density Al as a function of temperature up to 10 6 K.It is important to differentiate between the type of heating-reflectivity experiment reported here and those conducted with high-energy (> 100 mJ), long-duration ( > 50 psec) pulses. In the latter, the majority of the en-ergy is absorbed not by the dense target, but rather by the material expanding away from the interface over a scale of many wavelengths. Detailed hydrodynamic calculations are usually required to analyze the data from this type of experiment, l and no simpl...

The temperature equilibration rate between electrons and protons in dense hydrogen has been calculated with molecular dynamics simulations for temperatures between 10 and 600eV and densities between 10;{20}cm;{-3}to10;{24}cm;{-3} . Careful attention has been devoted to convergence of the simulations, including the role of semiclassical potentials. We find that for Coulomb logarithms L greater, similar1 , a model by Gericke-Murillo-Schlanges (GMS) [D. O. Gericke, Phys. Rev. E 65, 036418 (2002)] based on a T -matrix method and the approach by Brown-Preston-Singleton [L. S. Brown, Phys. Rep. 410, 237 (2005)] agrees with the simulation data to within the error bars of the simulation. For smaller Coulomb logarithms, the GMS model is consistent with the simulation results. Landau-Spitzer models are consistent with the simulation data for L>4 .

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Extreme ultraviolet (EUV) radiation from laser-produced plasma (LPP) has been thoroughly studied for application in mass production of next-generation semiconductor devices. One critical issue for the realization of an LPP-EUV light source for lithography is the conversion efficiency (CE) from incident laser power to EUV radiation of 13.5-nm wavelength (within 2% bandwidth). Another issue is solving the problem of damage caused when debris reaches an EUV collecting mirror. Here, we present an improved power balance model, which can be used for the optimization of laser and target conditions to obtain high CE. An integrated numerical simulation code has been developed for the target design. The code agrees well with experimental results not only for CE but also for detailed EUV spectral structure. We propose a two-pulse irradiation scheme for high CE, and reduced ion debris using a carbon dioxide laser and a droplet or a punch-out target. Using our benchmarked numerical simulation code, we find a possibility to obtain CE up to 6–7%, which is more than twice that achieved to date. We discuss the reduction of ion energy within the two-pulse irradiation scheme. The mitigation of energetic ions by a magnetic field is also discussed, and we conclude that no serious instability occurs due to large ion gyroradius.

We study femtosecond-laser-pulse-induced electron emission from W(100), Al(110), and Ag(111) in the subdamage regime (1-44 mJ/cm 2 fluence) by simultaneously measuring the incident-light reflectivity, total electron yield, and electron-energy distribution curves of the emitted electrons. The total-yield results are compared with a space-charge-limited extension of the Richardson-Dushman equation for short-time-scale thermionic emission and with particle-in-a-cell computer simulations of femtosecond-pulsed-induced thermionic emission. Quantitative agreement between the experimental results and two calculated temperaturedependent yields is obtained and shows that the yield varies linearly with temperature beginning at a threshold electron temperature of -0.25 eV The particle-in-a-cell simulations also reproduce the experimental electronenergy distribution curves. Taken together, the experimental results, the theoretical calculations, and the results of the simulations indicate that thermionic emission from nonequilibrium electron heating provides the dominant source of the emitted electrons. Furthermore, the results demonstrate that a quantitative theory of space-charge-limited femtosecond-pulse-induced electron emission is possible.

We report measurements of laser absorption for high-contrast ultrashort pulses on a variety of solid targets over an intensity range of 10'3 to 10's W/cm2. These data give an experimental determination of the target energy content and an indirect measure of dense plasma electrical conductivity. Our calculations accurately reproduce the behavior of aluminum targets, while the other materials show signs of additional absorption mechanisms. At high intensity all target materials reach a "universal plasma mirror" state and reflect about 90% of the incident light.