arXiv subjects

M. VanDusen-Gross

Publications and source records attributed to M. VanDusen-Gross.

3 recordsLinked to original sources

arXiv2026

Experimental demonstration of Flying-Focus enhanced Thomson scattering

We report the experimental demonstration of a spatiotemporally engineered "Flying-Focus" laser pulse for enhanced x-ray generation in relativistic Thomson scattering. A combination of longitudinal chromatic aberration, angular dispersion, and group delay dispersion was applied to an ultrashort relativistically intense laser pulse to control the motion of its focal point. Precise tuning of the group delay dispersion was used to match the velocity of the focus to the trajectory of a counterpropagating electron bunch, produced by a laser wakefield accelerator. This prolonged the Thomson scattering interaction while reducing nonlinear effects, leading to an enhanced x-ray yield. The approach has the potential to increase the spectral density and brightness of the x-ray beam by orders of magnitude compared to equivalent focusing without spatiotemporal control. This experiment establishes a new technique for structured-light control at high intensity, demonstrating the realization of dynamic intensity structures that enhance light-matter interactions and for the generation of ultra-bright radiation sources.

physics.optics↗

arXiv2026

Ion-motion-driven enhancement of energy coupling and stability in relativistic laser-microchannel interaction

For sufficiently short relativistic-intensity laser pulses, the disparity in time scales for electron and ion motion causes ions to behave as a fixed, neutralizing background. As the pulse duration or intensity is increased, ion motion becomes important, leading to instability in uniform plasmas but more complex, and potentially desirable behavior in structured targets. In this work, we introduce a new self-organized regime in laser-driven microchannels wherein ion motion facilitates stronger peak fields and high charge and photon conversion efficiency. 3-D particle-in-cell simulations demonstrate that the qualitative laser-microchannel interaction regime is governed by similarity parameters relating the pulse duration, spot size, and intensity to channel scales. The observed similarity suggests that lower-intensity experiments can inform designs for next-generation facilities, where the high-field, highly-radiative properties of the self-organized regime are especially desirable.

physics.plasm-ph↗

arXiv2025

Joule-Class Pulsed THz Sources from Microchannel Targets

Inference of joule-class THz radiation sources from microchannel targets driven with hundreds of joule, picosecond lasers is reported. THz sources of this magnitude are useful for nonlinear pumping of matter and for charged-particle acceleration and manipulation. Microchannel targets demonstrate increased laser-THz conversion efficiency compared to planar foil targets, with laser energy to THz energy conversion up to approximately 0.9% in the best cases.

physics.plasm-ph↗