title: Influence of initial time of laser ultrasonic on calculating its propagation velocity in a diamond anvil cell.
abstract: Sound velocity is important to study the elastic behaviors of materials in high pressure physics and the accuracy acquisition of travel time for velocity calculation is very essential. Thermoelastic finite element models of ultrasonic displacement field induced by a subnanosecond pulsed laser in metal films with a diamond anvil cell are established and the processes of laser ultrasonic generation are analyzed in detail. By confirming the initial time, we improved the accuracy of calculating the longitudinal wave velocity in the aluminum and copper thin films. The formulas of delay time are obtained by a set of simulations, and the overall errors of modified longitudinal velocity are reduced by 10-60 times of the unmodified ones.
authors.affiliation: Shaanxi Key Laboratory of Optical Information Technology, Ministry of Education, School of Science, Northwestern Polytechnical University, Xi'an 710072, China.
authors.forename: Yuning
authors.initials: Y
authors.lastname: Guo
authors.forename: Dexing
authors.initials: D
authors.lastname: Yang
authors.forename: Wen
authors.initials: W
authors.lastname: Feng
authors.forename: Xiangchao
authors.initials: X
authors.lastname: Zhu
authors.forename: Ying
authors.initials: Y
authors.lastname: Chang