Laser Short-Pulse Heating of Gold–Copper Two-Layer Assembly: Thermo-Elasto-Plastic Analysis

Abstract

Nuclei moving through magnetized materials at high velocities are subject to very intense transient magnetic fields, resulting from the ion-solid interaction in the polarized material. The transient field has been used for g-factor measurements of short-lived nuclear states for more than a decade. Still the origin of the field is not fully explained. The present paper presents a detailed discussion of the inherent assumptions of a model based on polarized bound electrons (PBE). The contact fields from unpaired s electrons are calculated for all ions, and a number of possible polarization mechanisms are discussed in detail. Extensive studies of K-shell populations of light ions, from 0 through S, penetrating ferromagnetic solids are summarized, referring to a separate paper for details. Based on these known K-shell populations the PBE model, including a contribution from scattered polarized electrons, is compared with all available data for ions of C through S in magetized iron, cobalt, nickel, and gadolinium. The quantative agreement with the data is found to be very good if all ionic electrons are assumed to be polarized to a degree of 0.14 and 0.20 in iron and gadolinium, respectively. Furthermore, simple estimates based on the PBE model are found to reproduce the gross features of the transient field for heavier ions in iron as well as gadolinium. The processes responsible for the polarization of the deeply bound electrons are, however, still not understood in detail.

Laser short-pulse heating with time-varying intensity and thermal stress development in the lattice subsystem

“…However, owing to the short time (of the order of 10 212 s), experimental measurements of stress could not be carried out. Since the use of the FEM code (ANSYS) in the stress simulations is well established and the predictions are almost in qualitative agreement with the previous results [19,29,30], the authors are satisfied with the accuracy of the predictions. The stability criterion is assured when selecting the time and space increments in the computer program [30].…”

“…Yilbas [12] introduced an electron kinetic theory approach to model the laser heating process. Later, the model was extended to include three-dimensional effects, multilayer structures, and phase change processes [13][14][15][16][17][18][19][20][21].…”

Sharp Spectral Variations of the Ultrafast Transient Light Extinction by Bimetallic Nanoparticles in the Near‐UV

“…A more rigorous approach would have consisted in accounting for the thermal resistance at the Au/Ag interface and the difference in the electron–phonon (e–ph) coupling constants, heat capacities, and thermal conductivities of the two metals, which would have induced a discontinuity in the thermal dynamics at the boundary. [ 45 ] However, for the case of a Au/Ag interface, it has been shown by Yilbas [ 46 ] that the short‐pulse induced dynamics of both T e and T l are smooth (i.e., without discontinuities at the interface). Therefore, the influence of the Au/Ag thermal resistance is negligible.…”

Study into laser short-pulse heating of a layered structure

“…He indicated that non-equilibrium heating had significant effects on laser-induced thermo-mechanical phenomena. Yilbas [14][15][16][17][18], Yilbas and Shuja [19], and Yilbas and Arif [20] studied the laser short-pulse heating process and predicted temperature rise, entropy generation rate, and thermo-mechanical responses in metallic materials.…”