| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
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| Symposium
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Processing and Performance of Materials Using Microwaves, Electric and Magnetic Fields, Ultrasound, Lasers, and Mechanical Work – Rustum Roy Symposium
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| Presentation Title |
K-19: Effect of Plasma Shielding in Laser Irradiation of Metal Targets with Bursts of Ultrashort Pulses |
| Author(s) |
Michael Stokes, Zhibin Lin, Alexey N Volkov |
| On-Site Speaker (Planned) |
Michael Stokes |
| Abstract Scope |
Pulsed laser ablation has applications for microscale material processing including material removal. The absorption of incident laser radiation in the expanding plume of ablation products results in the partial shielding of the target reducing efficiency of the material processing. In the present work, the shielding effect for a burst of ultrashort laser pulses is predicted using a computational model that combines a non-equilibrium collision-radiation model for the plasma plume with the two-temperature model of laser heating that accounts for finite time of electron and lattice coupling in the target material. The model accounts for absorption of laser radiation through multiphoton ionization and inverse bremsstrahlung as well as ionization and recombination processes. Simulations performed for single, double, and triple ultrashort laser pulses with a duration of 400 fs – 100 ps and repetition rates on the GHz scale indicate that the degree of plasma shielding strongly depends on the inter-pulse separation. This work was supported by the MKS Instruments, Inc. and NSF through EPSCoR CPU2AL project (award 1655280). The computational support is provided by the Alabama Supercomputer Center. |