Manipulating the spin of ultrarelativistic charged particle beams is a cornerstone of high-energy physics, yet its practical implementation has been limited by intrinsic energy dependence and a lack of universality across particle species. Here, we introduce the concept of a “unipolar surface wave s…

[Phys. Rev. Lett. 137, 125001] Published Tue Sep 15, 2026

X-ray free-electron lasers (XFELs) enable the exploration of matter with atomic-scale spatiotemporal resolution. Generating radiation wavelengths below one angstrom is critical for applications such as crystallography and Mössbauer studies. Until now, achieving the subangstrom regime has required el…

[Phys. Rev. Lett. 137, 115001] Published Fri Sep 11, 2026

The generation of energetic and dense plasmas by femtosecond laser pulses within the bulk of solids can pave the way to study warm dense matter, shocks, extreme UV radiation, or the synthesis of new material phases. However, this has remained elusive because of the intrinsic dynamical effects of def…

[Phys. Rev. Lett. 137, 115101] Published Thu Sep 10, 2026

A generalized ignition-accessibility framework is developed that unifies Lawson power balance, Cordey accessibility, the marginal ignition ridge, ignition entry points, and Mills thermal-runaway dynamics into a single self-consistent description of reactor-relevant burning plasmas. The 0D analysis r…

[Phys. Rev. Lett. 137, 115102] Published Thu Sep 10, 2026

The statistical properties of solar flare occurrence are critical for understanding coronal energy release, yet the nature of their underlying dynamics remains heavily debated. Analyzing over two decades of soft x-ray observations from a comprehensive geostationary operational environmental satellit…

[Phys. Rev. Lett. 137, 115201] Published Wed Sep 09, 2026

We present a theoretical and numerical study of resonant surface-plasmon (SP) excitation driven by the beating of two copropagating laser pulses on a smooth cylindrical plasma-vacuum interface. Analytical formulas for the SP dispersion relation, field amplitude, geometric coupling factor, and resona…

[Phys. Rev. Lett. 137, 105002] Published Fri Sep 04, 2026

Using high-power lasers to drive highly magnetized plasmas, researchers have probed the stellar processes that control coronal mass ejections.

[Phys. Rev. Lett. 137, 105201] Published Fri Sep 04, 2026

Laser wakefield accelerators are bright, compact sources of synchrotronlike x-rays. By driving the wakefield using a 110 TW laser in a variable length gas cell, we are able to map the evolution of the electron beam and resulting x-ray emission. We find that using a laser pulse initially focused to l…

[Phys. Rev. Lett. 137, 105001] Published Thu Sep 03, 2026

Nonlinear stability in magnetically confined plasmas is governed not only by local linear growth, but is fundamentally a connectivity property of the flux surface, governed by a topological percolation threshold.

[Phys. Rev. Lett. 137, 105101] Published Tue Sep 01, 2026

We reconsider the footprints of radiation friction in a head-on collision of a bunch of relativistic charged particles with a laser pulse by demonstrating that forward and backward radiation and radiation friction are coherently enhanced in a dense bunch. This opens an avenue to observe radiation fr…

[Phys. Rev. Lett. 137, 095001] Published Thu Aug 27, 2026

Instabilities driven by energetic particles normally reduce fusion power, but recent studies find Alfvén eigenmode instabilities can drive “zonal” flows and currents that reduce thermal transport, improving overall performance. Motional Stark effect data from the DIII-D tokamak reveal changes in mag…

[Phys. Rev. Lett. 137, 095101] Published Tue Aug 25, 2026

With the achievement of thermonuclear ignition, there is interest to increase the performance of inertial-confinement-fusion (ICF) systems to reach high fusion yields and high-energy gain for energy-production purposes. One approach to achieve this is magnetic-direct-drive (MDD) ICF, where magnetic …

[Phys. Rev. Lett. 137, 075102] Published Wed Aug 12, 2026

Self-generated magnetic fields in laser-solid interactions are experimentally characterized to reveal the 3D location and local field strength, rather than path-integrated quantities, using multiview proton radiography and tomographic inversion. We infer magnetic fields that extend several millimete…

[Phys. Rev. Lett. 137, 075101] Published Mon Aug 10, 2026

Recasting fusion coil design as a highly nonconvex equality-constrained optimization problem with an augmented Lagrangian method leads to a class of stellarator coils that exhibit enhanced physics performance and meet essential design requirements.

[Phys. Rev. Lett. 137, 065101] Published Fri Aug 07, 2026

Open questions in collisionless plasma dissipation can be addressed using space-based observations in different astrophysical environments, with implications for both astrophysical and laboratory plasma systems. We study a low-$\beta$, highly imbalanced, sub-Alfvénic stream observed by Parker Solar Probe …

[Phys. Rev. Lett. 137, 065201] Published Thu Aug 06, 2026

Supercomputer simulations reveal how turbulence supports a Goldilocks regime for operating a fusion reactor.

[Phys. Rev. Lett. 137, 055102] Published Thu Jul 30, 2026

The interaction between relativistic electron beams and intense laser fields has been extensively studied for generating high-energy radiation. However, achieving coherent radiation from such interactions needs to precisely control the phase matching of the radiating electrons, which has proven to b…

[Phys. Rev. Lett. 137, 055101] Published Tue Jul 28, 2026

We investigate analytically and numerically the interaction of strong electromagnetic waves with unmagnetized pair plasmas. We show that the interaction is governed by a single nonlinearity parameter, ${ϵ}_{\mathrm{p}}$, defined as the ratio of the wave strength parameter to the wave frequency in units of the plasm…

[Phys. Rev. Lett. 137, 045102] Published Wed Jul 22, 2026

Understanding nonlinear saturation of reversed-shear Alfvén eigenmodes (RSAEs) in tokamaks is crucial for high-performance burning plasmas. Employing both nonlinear gyrokinetic simulations and theoretical analyses, we have discovered the novel result that, with energetic particle dynamics kept linea…

[Phys. Rev. Lett. 137, 045101] Published Tue Jul 21, 2026

Relativistic magnetized shocks are natural sources of coherent radiation, representing a promising framework for fast radio bursts (FRBs). This Letter explores how the radiation reaction (RR) effect, triggered by high-energy photon emissions during shock radiation, significantly alters particle dyna…

[Phys. Rev. Lett. 137, 045201] Published Tue Jul 21, 2026

Recent X-point radiator (XPR) experiments in L-mode plasmas of the tungsten-W Environment in Steady-state Tokamak (WEST) tokamak show that a stable radiative ring can be sustained above the X point for approximately 70 s, on timescales not limited by intrinsic plasma physics, demonstrating the compa…

[Phys. Rev. Lett. 137, 035104] Published Thu Jul 16, 2026

Future applications of the spectrally narrow x-ray resonances in Mössbauer nuclei require x-ray sources with exceptionally high peak and average spectral flux. Here, we introduce a superradiant parametric Mössbauer radiation (SPMR) source, which utilizes the scattering of spatially microstructured e…

[Phys. Rev. Lett. 137, 035001] Published Wed Jul 15, 2026

The origin of the difference in the high-confinement ($H$-mode) power threshold between favorable and unfavorable drift configurations in tokamaks—experimentally linked to a deeper radial electric field ($E_r$) well in the former—remains unresolved. Using first-principles gyrokinetic simulations of edge …

[Phys. Rev. Lett. 137, 035103] Published Wed Jul 15, 2026

Gyrokinetic simulations of a turbulence-reduced Wendelstein 7-X discharge—characterized by a steep density gradient, moderate temperature gradients, and low plasma beta—show that microtearing mode (MTM) turbulence dominates transport. The simulated heat and particle fluxes agree with experimental me…

[Phys. Rev. Lett. 137, 035102] Published Tue Jul 14, 2026

Recent theoretical studies suggest that solenoidal turbulence can significantly enhance fusion reactivity, yet no standard diagnostic exists to directly measure these solenoidal flows in high-energy-density plasmas, nor to distinguish between solenoidal and compressional turbulence. We propose a met…

[Phys. Rev. Lett. 137, 035101] Published Mon Jul 13, 2026

Three-dimensional spiral injection enables beam storage in ultracompact rings with nanosecond revolution periods. We report first storage of a $297\mathrm{keV}/c$ electron beam in a 22 cm weak-focusing ring with a 4.7 ns revolution period using a 140 ns kicker pulse. A scintillating-fiber detector observes s…

[Phys. Rev. Lett. 137, 025002] Published Fri Jul 10, 2026

We report the first experimental demonstration of directional and collimated electron acceleration in the direct laser acceleration regime using a relativistic hollow Laguerre-Gaussian (LG) laser. Electrons are confined within the hollow field distribution along the reflected laser direction, produc…

[Phys. Rev. Lett. 137, 025001] Published Tue Jul 07, 2026

The observation of filamentary x-ray structures near bow-shock pulsar wind nebulae (PWNe)—such as the Guitar, Lighthouse, and PSR $\mathrm{J}2030+4415$ nebulae—and of slow-diffusion regions around pulsars like Geminga, Monogem, and PSR $\mathrm{J}0622+3749$, challenges the standard picture of cosmic-ray transport in the …

[Phys. Rev. Lett. 137, 025201] Published Mon Jul 06, 2026

Ion-driven plasma instability thresholds, derived from linear theory, constrain the distribution of solar observations in parameter space, defining boundaries of stable plasma parameters. Excursions beyond these thresholds result in the emission of energy, transferred from particles to coherent elec…

[Phys. Rev. Lett. 136, 255201] Published Wed Jun 24, 2026

The robust diagnosis of conditions generated in warm dense matter experiments remains a persistent challenge. Here, we describe the measurement of shock-compressed aluminium at 50 GPa with angle-resolved femtosecond x-ray Thomson scattering (XRTS) over a wide range of scattering wave vectors at the …

[Phys. Rev. Lett. 136, 245102] Published Thu Jun 18, 2026

The realization of compact laser-plasma accelerator (LPA) driven free electron lasers (FELs) has been attempted for nearly two decades, yet, difficult to overcome electron beam quality and stability issues prevented FEL lasing until recently. LPA based FEL is now demonstrated in both the self-amplif…

[Phys. Rev. Lett. 136, 245001] Published Tue Jun 16, 2026

Asymmetry of the compressed fusion fuel configuration, as characterized by a variation in areal density, in inertial confinement fusion (ICF) implosions is a known performance limitation. While ignition has been achieved on the National Ignition Facility (NIF), implosion symmetry was not perfect, an…

[Phys. Rev. Lett. 136, 245101] Published Tue Jun 16, 2026

Accurate ionization balance of gold plasmas in nonlocal thermodynamic equilibrium is essential for understanding the physics involved in inertial confinement fusion (ICF) hohlraums, where the persistent “drive deficit” issue may stem from an overestimation of the emission and absorption opacity of g…

[Phys. Rev. Lett. 136, 225101] Published Wed Jun 03, 2026

A scaling framework unifying the markedly different and independently studied cylindrical and spherical shock convergence is presented. For ionizing argon, we show that the focal temperature becomes invariant to shock symmetry and initial shock conditions when scaled by the prefocus shock Mach numbe…

[Phys. Rev. Lett. 136, 215101] Published Thu May 28, 2026

A new energetic-particle mode exhibits similarities to drift–bounce resonances in Earth’s magnetosphere and has been observed in a field-reversed plasma configuration using the NORM fusion device.

[Phys. Rev. Lett. 136, 205101] Published Fri May 22, 2026

An adapted optical technique reveals the temporal structure of ultrafast x-ray pulses by eliminating background light.

[Phys. Rev. Lett. 136, 195002] Published Tue May 12, 2026

By leveraging a recently developed slippage-compensation scheme in externally seeded free-electron lasers (FELs), we propose a method for generating few-femtosecond extreme-ultraviolet (XUV) pulse pairs with tunable topological properties and adjustable temporal delay. Simulations show that the topo…

[Phys. Rev. Lett. 136, 195001] Published Mon May 11, 2026

An intense electron beam is stopped more efficiently by a highly porous material than by a less porous material, suggesting new strategies for controlling beams.

[Phys. Rev. Lett. 136, 185102] Published Fri May 08, 2026

In a tokamak plasma, we measure nonlinear coupling between harmonics comprising a saturated edge oscillation, as predicted by nonlinear magnetohydrodynamic simulations. The coherent structure formed by this coupling suppresses bursty edge-localized modes that cause energy and particle loss. We also …

[Phys. Rev. Lett. 136, 185101] Published Wed May 06, 2026

The Richtmyer-Meshkov instability (RMI) poses a major challenge in inertial confinement fusion (ICF) due to its role in mixing and performance degradation. We report the first experimental observation of passive freeze-out of RMI in a low-pressure surrogate regime, an instability stagnation effect i…

[Phys. Rev. Lett. 136, 145102] Published Fri Apr 10, 2026

Understanding and controlling the seeding of hydrodynamic perturbations are crucial for achieving ignition and high gain in inertial confinement fusion (ICF). In this Letter, we present face-on radiography of planar foil with preimposed sinusoidal ripples, revealing a novel phenomenon that the pertu…

[Phys. Rev. Lett. 136, 145103] Published Fri Apr 10, 2026

Experimental demonstration of the radial acceleration of protons in a low-mass hybrid $X$ pinch shows that an $X$-pinch-driven proton source could be a novel platform to study pulsed-power plasmas.

[Phys. Rev. Lett. 136, 145101] Published Tue Apr 07, 2026

Flat hadron beam collisions, though expected to enhance peak luminosity by about an order of magnitude, have not yet been demonstrated. We identify a new mechanism in which the hourglass-induced synchrobetatron resonance, when coupled to unavoidable machine fluctuations, drives emittance transfer an…

[Phys. Rev. Lett. 136, 135001] Published Wed Apr 01, 2026

Thomson-scattering signals can be significantly modified by convective gains associated with the stimulated Raman scattering and stimulated Brillouin scattering instabilities as the scattered light traverses the probe beam. Gain results in amplification and narrowing of the redshifted (i.e., Stokes)…

[Phys. Rev. Lett. 136, 135101] Published Tue Mar 31, 2026

The growth rate of the Alfvén wave parametric decay instability, a process that contributes to energy transfer in plasmas, provides a new benchmark for space plasma models of space weather disturbances.

[Phys. Rev. Lett. 136, 135201] Published Tue Mar 31, 2026

We report the first demonstration of a minute-scale, edge-localized-mode-free high-confinement plasma regime compatible with divertor partial detachment and enhanced pedestal performance in a metal-wall tokamak, the Experimental Advanced Superconducting Tokamak. This regime is enabled by a newly ide…

[Phys. Rev. Lett. 136, 125101] Published Mon Mar 23, 2026

It is demonstrated that the peak toroidal impact phase of the post-disruption runaway electrons (REs) can be varied shot to shot by means of applied static nonaxisymmetric (3D) magnetic fields, or resonant magnetic perturbations (RMPs). In the experiments, high-current (500 kA), purged RE plateaus (…

[Phys. Rev. Lett. 136, 125102] Published Mon Mar 23, 2026

Understanding plasma self-magnetization is one of the fundamental challenges in both laboratory and astrophysical plasmas. Self-magnetization can modify plasma transport properties, altering the dynamical evolution of plasmas. Multiple high-energy-density (HED) experiments have observed the formatio…

[Phys. Rev. Lett. 136, 115101] Published Fri Mar 20, 2026

The relaxation of many physical systems is constrained by collisions. However, most space and astrophysical plasmas are nearly collisionless, leaving open questions about the pathways of energy transfer and dissipation. In many turbulent plasmas, the electric field takes on the role of energy transf…

[Phys. Rev. Lett. 136, 105201] Published Fri Mar 13, 2026

Electrons accelerated to relativistic speeds in a dielectric material can produce bursts of x rays, similar to a phenomenon found in thunderstorms.

[Phys. Rev. Lett. 136, 095301] Published Thu Mar 05, 2026

Using particle-in-cell simulations that label ions and electrons according to their initial inflow region, we find that during 2D collisionless magnetic reconnection, the bulk flow of the plasma from each inflow side crosses paths with plasma from the other inflow side and crosses the midplane befor…

[Phys. Rev. Lett. 136, 085201] Published Fri Feb 27, 2026

Electromagnetic radiation by accelerated charges is a fundamental process in physics. Here, we introduce a quantum-optical framework for controlling the emission of radiation of an electron in an intense laser field via squeezed vacuum states. By engineering the quantum fluctuations of the emission …

[Phys. Rev. Lett. 136, 085001] Published Tue Feb 24, 2026

While conventional experiments typically employ plane-wave states of particles with definite momenta, vortex states represent cylindrical waves carrying an orbital angular momentum (OAM) projection along the propagation direction. This projection can be arbitrarily large, granting charged particles …

[Phys. Rev. Lett. 136, 085002] Published Tue Feb 24, 2026

Temporal transition of an externally driven antiparallel asymmetric magnetic reconnection from collisional slow to collisionless fast regime is observed in a laboratory plasma for the first time. This transition is initiated when the two-fluid Hall effect begins to dominate over collisional effects …

[Phys. Rev. Lett. 136, 085101] Published Tue Feb 24, 2026

Centrifugal plasma traps, in which plasma is confined partly by centrifugal forces, represent a possible path to fusion energy production. In centrifugal plasma traps, electric fields naturally arise in the direction parallel to the magnetic field in order to ensure quasineutrality. These electric f…

[Phys. Rev. Lett. 136, 085102] Published Tue Feb 24, 2026

Multiturn charge-exchange injection is the primary method of creating high-intensity hadron beams in circular accelerators, and phase space painting during injection enables tailoring of the accumulated phase space distribution. A technique we call eigenpainting allows injection of particles into a …

[Phys. Rev. Lett. 136, 075002] Published Fri Feb 20, 2026

We examine the Ramo current in a nanoscale planar vacuum diode undergoing field emission in the presence of a DC voltage supply and an external resistor. We describe a simple mechanism for generating persistent current oscillations in the diode due to the voltage drop across the external resistor (b…

[Phys. Rev. Lett. 136, 075003] Published Fri Feb 20, 2026

A global, confinement-time-long, flux-driven turbulence simulation of the tokamak plasma edge region subject to a power ramp reproduces an abrupt turbulence transition.

[Phys. Rev. Lett. 136, 075101] Published Thu Feb 19, 2026

This Letter reports the simultaneous excitation of two terahertz plasma waves in field-emission-driven microdischarges. As demonstrated by first-principle particle-in-cell simulations, we reveal that one wave results from intermittent field emission due to space-charge effects, while the other arise…

[Phys. Rev. Lett. 136, 075001] Published Wed Feb 18, 2026

We combine simulations with new analyses that overcome previous pitfalls to explicate how nonhelical mean-field dynamos grow and saturate in unstratified, magnetorotationally driven turbulence. Shear of the mean radial magnetic field amplifies the azimuthal component. Radial fields are regenerated b…

[Phys. Rev. Lett. 136, 075201] Published Wed Feb 18, 2026

We report the first experimental observation of carrier-envelope phase-driven energy bunching in laser wakefield acceleration. Using a few-cycle ($\sim 9\mathrm{fs}$), multiterawatt laser pulse and ionization injection in a helium-nitrogen gas mixture, we observe electron spectra composed of multiple quasimonoen…

[Phys. Rev. Lett. 136, 065001] Published Tue Feb 10, 2026

Transport of relativistic electron beams (REBs) in matter underpins a wide range of plasma, accelerator, radiation source, and material physics. Here we report a previously unexplored superchanneling regime of REB propagation in disordered porous materials composed of randomly structured solid-densi…

[Phys. Rev. Lett. 136, 055001] Published Wed Feb 04, 2026

Axisymmetric Alfvén eigenmodes have been observed at the plasma edge in deuterium-tritium (D-T) tokamak plasmas externally heated only by neutral beam injection in JET. The modes were detected only in D-T plasmas, not in pure D plasmas, indicating excitation by fusion-born $\alpha$ particles. The presence …

[Phys. Rev. Lett. 136, 055101] Published Wed Feb 04, 2026

Inertial confinement fusion is likely to require significant improvements in technology and design for large targets to implode at high driver energies. To assess the potential for benefits, we report on nuclear performance as a function of target radius $R_{\mathrm{t}}$ in direct-drive cryogenic implosions as pe…

[Phys. Rev. Lett. 136, 045101] Published Mon Jan 26, 2026

Vortex $\gamma$ photons carrying orbital angular momenta (OAM) hold great potential for various applications. However, their generation remains a great challenge. Here, we successfully generate sub-MeV vortex $\gamma$ photons via all-optical inverse Compton scattering of relativistic electrons colliding with a su…

[Phys. Rev. Lett. 136, 025001] Published Wed Jan 14, 2026

Helicon waves (also known as whistler waves) satisfying the normal wave-particle cyclotron resonance are observed to limit the growth and maximum energy of relativistic electrons (REs) in low-density Ohmic DIII-D tokamak plasmas. Following the application of helicon waves, pitch-angle scattering of …

[Phys. Rev. Lett. 136, 025101] Published Wed Jan 14, 2026

Studies have long suggested that shocks can undergo cyclical self-reformation as a type of shock nonstationarity. Until now, providing solid evidence for shock reformation in spacecraft observation and identifying its generating mechanisms remain challenging. In this Letter, by analyzing magnetosphe…

[Phys. Rev. Lett. 136, 025201] Published Tue Jan 13, 2026

Global gyrokinetic simulation of the ion temperature gradient mode shows that the radial electric field, $E_r$ well, upshifts the critical temperature gradient near the magnetic axis, in the weak but not in the strong magnetic shear ($s$) configuration. The geometric curvature effect almost cancels/doubl…

[Phys. Rev. Lett. 136, 015102] Published Mon Jan 05, 2026

Interactions between MHD-scale tearing modes (TMs) and ion-gyroradius-scale trapped-electron modes (TEMs) in a fusion plasma are simulated with global gyrokinetics, using a consistent set of fixed equilibrium profiles. Unstable core TMs nonlinearly couple and transfer energy to smaller-scale stable …

[Phys. Rev. Lett. 136, 015101] Published Fri Jan 02, 2026

Mode locking—a laser technique that revolutionized optical physics—has been extended to x rays, producing stable trains of attosecond pulses with unprecedented phase coherence.

[Phys. Rev. Lett. 135, 265001] Published Tue Dec 23, 2025

Mitigation and suppression of low-$k$ turbulence are observed during the nonlinear evolution of toroidicity-induced Alfvén eigenmodes (TAEs) in DIII-D experiments. Turbulence mitigation begins when the dominant TAE starts to depart from the typical shear Alfvén wave polarization. TAE activity then evo…

[Phys. Rev. Lett. 135, 265101] Published Mon Dec 22, 2025

Fast magnetosonic waves are one of the two low-frequency plasma modes that can exist in a neutron star magnetosphere. It was recently realized that these waves may become nonlinear within the magnetosphere and steepen into some of the strongest shocks in the universe. These shocks, when in the appro…

[Phys. Rev. Lett. 135, 265201] Published Mon Dec 22, 2025

We present a solvable scenario for 3D reconnection in a sheared magnetic field. We consider a localized external force that is applied slowly to a flux tube and then maintained, generating an Alfvénic perturbation that spreads along the field lines. Separation of the sheared field lines reduces the …

[Phys. Rev. Lett. 135, 255101] Published Thu Dec 18, 2025

Analysis of Parker Solar Probe data identifies stochastic magnetic moment breaking by intermittent structures in imbalanced turbulence as a viable heating mechanism in the sub-Alfvenic solar wind.

[Phys. Rev. Lett. 135, 255201] Published Thu Dec 18, 2025

The electron density and electric field govern physical and chemical reactions in a secondary streamer discharge under atmospheric-pressure air. We present direct combinational measurements of these essential quantities and demonstrate their consistency by solving the continuity equation for electro…

[Phys. Rev. Lett. 135, 245301] Published Mon Dec 08, 2025

Plasma-wall interactions are complex and often determine the overall operating regime of a plasma device. The region bridging the plasma to the wall, where potential and density gradients localize, is called the sheath. Particle-in-cell simulations showed that the sheath may become unstable when sec…

[Phys. Rev. Lett. 135, 235302] Published Thu Dec 04, 2025

We report the first direct observation using a retarding potential analyzer of time-resolved ion energy distribution functions (IDFs) in a Hall thruster (HT) on two distinct time scales corresponding to the breathing mode ($\sim \mathrm{kHz}$) and the ion transit time oscillation (ITTO, $\sim 100\mathrm{kHz}$). We combined the…

[Phys. Rev. Lett. 135, 235301] Published Wed Dec 03, 2025

Coupled 2D fluid-kinetic simulations of a DIII-D high confinement tokamak plasma show that plasma rotation coupled with drift effects near the plasma edge play a significant role in the creation of the observed poloidal distribution of neutrals. It is observed that including either drift or rotation…

[Phys. Rev. Lett. 135, 225101] Published Mon Nov 24, 2025

We explored the physics of efficient proton acceleration in a nanometer-thick polymer foil irradiated by an ultrahigh-contrast petawatt laser pulse. The longitudinal proton dynamics were experimentally investigated, indicating the acceleration of protons to over 90 MeV by a novel scheme associated w…

[Phys. Rev. Lett. 135, 215002] Published Fri Nov 21, 2025

We report the observation of transverse intensity fluctuations—spikes—in synchrotron radiation from a single undulator cell at the European XFEL after monochromatization. Autocorrelation analysis of the recorded events confirms that these fluctuations originate from the partial transverse coherence …

[Phys. Rev. Lett. 135, 215001] Published Thu Nov 20, 2025

We observed highly efficient manipulation of the 530 MeV positron beam at Mainz Microtron via bent crystals. The low beam divergence revealed a fine structure in the angular distribution of channeled particles. A compact analytical model, supported by Monte Carlo methods including multiple scatterin…

[Phys. Rev. Lett. 135, 205002] Published Thu Nov 13, 2025

Coherent synchrotron radiation (CSR) is crucial for the development of powerful ultrashort light sources. We present a mechanism for generating CSR in the form of generalised superradiance, based on surface plasmon polaritons (SPPs), which are resonantly excited on a solid, near-critical-density inn…

[Phys. Rev. Lett. 135, 205001] Published Wed Nov 12, 2025

Experiments with oxygen plasma at extreme densities and temperatures give new transparency to our picture of the Sun’s interior.

[Phys. Rev. Lett. 135, 205101] Published Wed Nov 12, 2025

The axion is a hypothetical particle associated with a possible solution to the strong CP problem and is a leading candidate for dark matter. In this Letter we investigate the emission of axions by accelerated electrons. We find the emission probability and energy within the WKB approximation for an…

[Phys. Rev. Lett. 135, 195003] Published Thu Nov 06, 2025

Plasma-based acceleration linear collider designs consist of many plasma stages where a drive beam drives a wake that accelerates a witness beam. Misalignment between the drive and witness beams can lead to the hosing instability, large emittance growth, and difficulty colliding beams at the final f…

[Phys. Rev. Lett. 135, 195002] Published Wed Nov 05, 2025

In this Letter, we present a robust method for generating custom-shaped, coherent hard x-ray pulses in regenerative amplifier free-electron lasers (RAFELs) using laser-induced energy modulation of the electron beam. A temporally shaped optical modulation imprints an optical-wavelength energy pattern…

[Phys. Rev. Lett. 135, 195001] Published Tue Nov 04, 2025

Ice grains formed in a cryogenically cooled plasma exhibit fractal morphologies that drive distinct collective dynamics. By measuring and quantifying the dynamics of these grains in a plasma afterglow, we observe a new fundamental dynamical regime induced by fractal scalings of ice mass and collisio…

[Phys. Rev. Lett. 135, 195301] Published Mon Nov 03, 2025

We introduce a data-driven approach to learn generalized collision operators from molecular dynamics. Unlike conventional models (e.g., Landau), the present operator takes a symmetry-breaking form that depends not only on the relative velocity but also on the average velocity of the collision pair, …

[Phys. Rev. Lett. 135, 185101] Published Tue Oct 28, 2025

The mirror instability is a fundamental phenomenon in plasma physics. Given the historical discussion regarding the role of resonant particles in driving this instability—which is at odds with its presence in magnetohydrodynamic (MHD) models that only describe fluid plasma behavior—we seek to clarif…

[Phys. Rev. Lett. 135, 185201] Published Mon Oct 27, 2025

A novel technique for measuring plasma conditions using monochromatic pump-broadband-probe laser interactions has been experimentally demonstrated. Originally proposed in Ludwig et al. [Phys. Plasmas 26, 113108 (2019)], this method utilizes crossed-beam energy transfer between the broadband probe an…

[Phys. Rev. Lett. 135, 175103] Published Wed Oct 22, 2025

Experiments in the Wendelstein 7-X (W7-X) stellarator with plasma density beyond the established density limit in stellarators [Scalings of energy confinement and density limit in stellarator/heliotron devices, Nucl. Fusion 30, 11 (1990).] resulted in unusual, reduced size, fully radiative plasmas l…

[Phys. Rev. Lett. 135, 175101] Published Tue Oct 21, 2025

Triparticle radiography combined with a reconstruction algorithm simultaneously recovers the spatiotemporal evolution of self-generated electric and magnetic fields in laser-driven hohlraum experiments.

[Phys. Rev. Lett. 135, 175102] Published Tue Oct 21, 2025

Electrostatic repulsion between electrons usually impairs the performance of electron microscopes. Now it can be turned into an advantage.

[Phys. Rev. Lett. 135, 165002] Published Wed Oct 15, 2025

High-order harmonic generation by the diffraction of an intense Laguerre-Gaussian (LG) laser beam through a small aperture is studied. It is found that the 2D peripheral electron dynamics at the boundary of the diffraction aperture can facilitate complex interplay between the spin and orbital angula…

[Phys. Rev. Lett. 135, 165001] Published Tue Oct 14, 2025

Low-energy electrons, with their large scattering cross sections and exceptional sensitivity to electric fields, have attracted considerable attention for probing ultrafast surface structural and electronic dynamics, particularly through techniques such as low-energy electron diffraction and imaging…

[Phys. Rev. Lett. 135, 155002] Published Thu Oct 09, 2025

The generation of intense, femtosecond-scale x-ray pulses is crucial for probing matter under extreme temporal and field conditions. Current chirped-pulse amplification (CPA) techniques in free-electron lasers (FELs), however, face efficiency limitations in the soft x-ray regime due to the inherent …

[Phys. Rev. Lett. 135, 155001] Published Tue Oct 07, 2025

Sheared flow increases the reactivity of fusion plasma. In unmagnetized plasma with flow gradients comparable to the mean free path of reacting ions, fusion reactivity can be more than doubled. The effect is of particular relevance to inertial confinement fusion (ICF), where it allows implosion kine…

[Phys. Rev. Lett. 135, 155101] Published Mon Oct 06, 2025

Researchers have shown experimentally that ultraintense lasers can drive high-amplitude surface plasma waves without the need for intricate structures.

[Phys. Rev. Lett. 135, 145001] Published Wed Oct 01, 2025

Relativistic structured spin-polarized (SSP) particle beams, characterized by polarization structures, are of critical importance in a wide range of applications, such as material properties investigation, imaging, and information storage. However, the generation of relativistic SSP beams faces sign…

[Phys. Rev. Lett. 135, 135001] Published Thu Sep 25, 2025

Shearing a dusty plasma with a laser shows how vibrational modes lead to weak points in an amorphous active system.

[Phys. Rev. Lett. 135, 135301] Published Wed Sep 24, 2025