Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2609.36964

Electron Rephasing in a Truncated Tunable Plasma Channel

Arujash Mohanty·Santhosh Krishnamurthy·Yinren Shou·Sheroy Tata·Anton Golovanov·Anda-Maria Talposi·Aaron Liberman·Eyal Kroupp·Victor Malka
View original source ↗Read source document ↗Export metadata ↓

Abstract

We report the acceleration of stable electron beams with energies up to 1.5 GeV using a 50 TW laser pulse guided in a preformed plasma channel generated by an axiparabola-focused heater pulse. Varying the channel length changes the plasma density beyond the channel end and produces distinct electron spectra. A short channel causes a large decrease in bubble size after the truncated channel, leaving only part of the electron bunch in the accelerating phase and resulting in a quasi-monoenergetic peak. For a longer channel ending near the target density down-ramp, the smaller density increase rephases and further accelerates a larger fraction of the bunch, producing a continuous high-charge spectrum. Hydrodynamic and particle-in-cell simulations reproduce the observed spectral evolution. Together, the measurements and simulations identify channel length as a key control parameter in guided laser-wakefield acceleration.

Explore related subjects

physics.plasm-phphysics.acc-phphysics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Arujash Mohanty, Santhosh Krishnamurthy, Yinren Shou, Sheroy Tata, Anton Golovanov, Anda-Maria Talposi, Aaron Liberman, Eyal Kroupp, Victor Malka. 2026-09-29. Electron Rephasing in a Truncated Tunable Plasma Channel. https://arxiv.org/abs/2609.36964

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

New Formalism for Modelling Flowing Plasmas in a Magnetic Field

A new formalism for modelling a flowing plasma in a magnetic field, having potential for application in plasma thrusters, materials processing, space plasmas, etc., is developed. In this framework, the plasma expands downstream from the source region into an expansion chamber along an axisymmetric magnetic field. For plasma flowing along a magnetic field, the ion velocity parallel to the magnetic field lines is much greater than the perpendicular velocity. This characteristic permits a unique ordering of the relevant flow variables when the flow equations are transformed into a magnetic coordinate system (MCS), in which the coordinate axes are parallel and perpendicular to the field lines. The ordering of the flow variables in the MCS further simplifies the flow equations by allowing them to be split into sets of reduced equations. As a specific implementation, the proposed formalism was validated by using data (for boundary conditions) from a small volume plasma system experiment (Ganguli et al 2016 Plasma Sources Sci. Technol. 25 025026). The model shows favourable agreement with the experiments and is used to predict various physical quantities relevant for applications. The corresponding physical implications are discussed in detail.

physics.plasm-ph↗
arXiv2026

Implicit-Explicit time integration scheme with Physics-based preconditioning for two-fluid tokamak boundary simulations

In this work, a globally stiffly accurate Implicit-Explicit (IMEX) Runge-Kutta scheme is developed and implemented in the GBS code [Ricci et al., Plasma Phys. Control. Fusion, 2012], for two-fluid plasma turbulence simulations. The stiffest phenomena, governed by shear Alfvén waves and parallel diffusion, are treated implicitly, while the remaining non-stiff terms are advanced explicitly. This splitting enables time steps well beyond the Courant-Friedrichs-Lewy limit, without incurring the full computational cost of a globally implicit formulation. To efficiently solve the implicit subsystem at each time step, a three-dimensional physics-based preconditioner, inspired by techniques developed in the magnetohydrodynamic (MHD) context, is used. The resulting framework is verified through the method of manufactured solutions and exhibits both algorithmic and parallel scalability. Significant advantages in numerical stability and computational efficiency are demonstrated with respect to an adaptive explicit Runge-Kutta scheme.

physics.plasm-ph↗
arXiv2026

Experimental demonstration of broadband-laser suppression of cross-beam energy transfer

In direct-drive inertial confinement fusion (ICF), cross-beam energy transfer (CBET) redirects a significant fraction of the incident laser energy out of the plasma. We report the experimental demonstration that broadband lasers reduce CBET-enhanced reflected-light return, performed at the low-coherence Kunwu laser facility with two crossed beams of 0.6% bandwidth and up to 550J at $\sim$2.6$\times$10$^{14}$ W/cm$^{2}$. A coupled ray-tracing model shows that the strong CBET amplification of narrowband reflected light is much weaker under broadband illumination. In symmetric incidence condition of two orthogonal beams, the total fractional scattered energy decreases from 7.57% to 4.64%; in asymmetric incidence condition, which separates stimulated Brillouin scattering (SBS) from specular reflection, the SBS fraction decreases from 3.75% to 0.46% and the specular-reflection fraction decreases from approximately 2.2% to 1.3%. These results establish broadband lasers as an effective, experimentally validated approach to reducing energy escape through CBET-enhanced reflection in direct-drive ICF.

physics.plasm-ph↗