Ultrafast Spin Rotation of Relativistic Lepton Beams via Terahertz Wave in a Dielectric-Lined Waveguide.

Spin rotation is central for the spin manipulation of lepton beams which, in turn, plays an important role in investigation of the properties of spin-polarized lepton beams and the examination of spin-dependent interactions. However, realization of compact and ultrafast spin rotation of lepton beams, between longitudinal and transverse polarizations, still faces significant challenges. Here, we put forward a novel method for ultrafast (picosecond timescale) spin rotation of a relativistic lepton beam via employing a moderate-intensity terahertz (THz) wave in a dielectric-lined waveguide (DLW).

Generation of Ultrabrilliant Polarized Attosecond Electron Bunches via Dual-Wake Injection.

Laser wakefield acceleration is paving the way for the next generation of electron accelerators, for their own sake and as radiation sources. A controllable dual-wake injection scheme is put forward here to generate an ultrashort triplet electron bunch with high brightness and high polarization, employing a radially polarized laser as a driver. We find that the dual wakes can be driven by both transverse and longitudinal components of the laser field in the quasiblowout regime, sustaining the laser-modulated wakefield which facilitates the subcycle and transversely split injection of the triplet bunch.

Electron acceleration by a radially-polarized laser pulse in a plasma micro-channel: erratum.

Three of the headings of Table 1, which have been switched by mistake in our paper, are corrected here. The rest of the paper, including all results and conclusions, remain intact.

Electron acceleration by a radially-polarized laser pulse in a plasma micro-channel.

Encouraged by recent advances in radially-polarized laser technology, simulations have been performed of electron acceleration by a tightly-focused, ultra-short pulse in a parabolic plasma micro-channel. Milli-joule laser pulses, generated at kHz repetition rates, are shown to produce electron bunches of MeV energy, pC charge, low emittance and low divergence. The pivotal role played by the channel length in controlling the process is demonstrated, and the roles of direct and wakefield acceleration are distinguished.

Fields of a Bessel-Bessel light bullet of arbitrary order in an under-dense plasma.

Considerable theoretical and experimental work has lately been focused on waves localized in time and space. In optics, waves of that nature are often referred to as light bullets. The most fascinating feature of light bullets is their propagation without appreciable distortion by diffraction or dispersion.

Feasibility of electron cyclotron autoresonance acceleration by a short terahertz pulse.

A vacuum auto-resonance accelerator scheme for electrons, which employs terahertz radiation and currently available magnetic fields, is suggested. Based on numerical simulations, parameter values, which could make the scheme experimentally feasible, are identified and discussed.

Dense monoenergetic proton beams from chirped laser-plasma interaction.

Interaction of a frequency-chirped laser pulse with single protons and a hydrogen gas target is studied analytically and by means of particle-in-cell simulations, respectively. The feasibility of generating ultraintense (10(7) particles per bunch) and phase-space collimated beams of protons (energy spread of about 1%) is demonstrated. Phase synchronization of the protons and the laser field, guaranteed by the appropriate chirping of the laser pulse, allows the particles to gain sufficient kinetic energy (around 250 MeV) required for such applications as hadron cancer therapy, from state-of-the-art laser systems of intensities of the order of 10(21) W/cm(2).

Fields of a focused linearly polarized Gaussian beam: truncated series versus the complex-source-point spherical-wave representation.

Fields of a linearly polarized fundamental Gaussian beam are derived exactly using the propagation characteristics of a complex-source-point spherical wave diverging from the origin. Intensity distributions are calculated and compared with their counterparts in a truncated series. It is found that utility of the exact fields is limited by a discontinuity inherent in the vector potential from which they have been obtained.

Direct high-power laser acceleration of ions for medical applications.

Theoretical investigations show that linearly and radially polarized multiterawatt and petawatt laser beams, focused to subwavelength waist radii, can directly accelerate protons and carbon nuclei, over micron-size distances, to the energies required for hadron cancer therapy. Ions accelerated by radially polarized lasers have generally a more favorable energy spread than those accelerated by linearly polarized lasers of the same intensity.

Acceleration in vacuum of bare nuclei by tightly focused radially polarized laser light.

Fields of a radially polarized petawatt laser beam, represented by a truncated series in the diffraction angle epsilon to order epsilon15 and focused to subwavelength waist radius, are shown to accelerate protons and bare nuclei to several hundred MeV per nucleon over a distance equivalent to a few laser wavelengths.

Mono-energetic GeV electrons from ionization in a radially polarized laser beam.

Fields of a radially polarized laser beam developed recently [Y. I. Salamin, Opt.

Fields of a radially polarized Gaussian laser beam beyond the paraxial approximation.

Analytic expressions for the fields of a tightly focused radially polarized Gaussian laser beam are derived, accurate to epsilon5, where epsilon is the associated diffraction angle. The fields satisfy Maxwell's equations, and the calculated beam power based on them is significantly different from that of the paraxial-approximation fields.

Relativistic electron dynamics in intense crossed laser beams: acceleration and Compton harmonics.

Electron motion and harmonic generation are investigated in the crossed-beam laser-accelerator scheme in a vacuum. Exact solutions of the equations of motion of the electron in plane-wave fields are given, subject to a restricted set of initial conditions. The trajectory solutions corresponding to axial injection are used to calculate precise emission spectra.

Electron acceleration by a tightly focused laser beam.

State-of-the-art petawatt laser beams may be focused down to few-micron spot sizes and can produce violent electron acceleration as a result of the extremely intense and asymmetric fields. Classical fifth-order calculations in the diffraction angle show that electrons, injected sideways into the tightly focused laser beam, get captured and gain energy in the GeV regime. We point out the most favorable points of injection away from the focus, along with an efficient means of extracting the energetic electron with a static magnetic field.