Variational method for inner-shell excitation in heavy-ion collisions
In the framework of the monopole model we study a perturbation method for inner-shell excitation which covers the whole projectile velocity region. This is achieved by introducing a velocity-dependent variational parameter and minimizing the time-dependent perturbation. We apply the method to theK-excitation of nonrelativistic systems.
Molecular Orbital X-Ray Emission in Heavy Ion Collisions
In a collision between two heavy atoms, distances of closest approach deep within the atomic K shell radii are attainable for values of the projectile velocity which are slow compared to those of the K shell electrons. Under these conditions, the projectile motion can be viewed as adiabatic and molecular-like electron orbitais evolve. In the limit as the target and projectile atoms are very close together, a transient quasiatom consisting of the combined electron clouds orbiting around the two centered nuclear Coulomb field will be formed.
Techno-economic analysis of solar thermal power plants using liquid sodium as heat transfer fluid
Abstract Solar thermal power plants with central receiver and thermal storage are expected to be one key technology in future electricity generation, because they are renewable and due to the thermal storage independent of the current solar radiation. State-of-the-art solar power plants often use molten nitrate salts as heat transfer fluid. The use of liquid sodium instead leads to lower electricity generation costs. Sodium has a high thermal conductivity and thus large heat transfer rates are possible. Hence, a smaller absorber surface is sufficient for the same thermal power. As a result, the sodium receiver achieves a higher efficiency at lower investment cost. Additionally, the aiming strategy, which reduces the peak heat flux on molten salt receivers isn’t necessary for sodium. Even at high heat flux densities, the absorber tubes will be cooled sufficiently due to the high heat transfer coefficients. Therefore, the sodium receiver in this analysis is designed for one single aim point, resulting in a heat flux density of q mean = 1.06 MW / m 2 and q peak = 2.99 MW / m 2 . The state-of-the-art system with molten salt considers q mean = 0.51 MW / m 2 and q peak = 1.0 MW / m 2 . The presented techno-economic analysis of two sodium based concepts compared to a reference system with molten salt results in up to 16% lower electricity generation costs.