We show that both the maximum energy gain and the accelerated beam quality can be efficiently controlled by the plasma-density profile. Choosing a proper density gradient one can uplift the dephasing limitation and keep the phase synchronism between the bunch of relativistic particles and the plasma wave over extended distances. Putting electrons into the n th wake period behind the driving laser pulse, the maximum energy gain is increased by the factor, which is proportional to n, over that in the case of uniform plasma. Layered plasma is suggested to keep the resonant condition for laser-wakefield excitation. The acceleration is limited then by laser depletion rather than by dephasing. Further, we show that the natural energy spread of the particle bunch acquired at the acceleration stage can be effectively removed by a matched deceleration stage, where a larger plasma density is used.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevE.77.025401 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Generation of highly stable electron beam via the control of hydrodynamic instability.
Sci Rep
December 2024
SANKEN (Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.
By employing the stabilizer in the supersonic gas nozzle to produce the plasma density profile with a sharp downramp, we have experimentally demonstrated highly stable electron beam acceleration based on the shock injection mechanism in laser wakefield acceleration with the use of a compact Ti:sapphire laser. A quasi-monoenergetic electron beam with a peak energy of 315 MeV ± 12.5 MeV per shot is generated.
View Article and Find Full Text PDFOrigin of Spectral Bands in the Crab Pulsar Radio Emission.
Phys Rev Lett
November 2024
Institute for Advanced Study, School for Natural Sciences, Princeton, New Jersey 08540, USA; Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA; Institute for Theory and Computation, Harvard University, Cambridge, Massachusetts 02138, USA; Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, USA; and Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Article Synopsis
- - A new model has been developed to explain the high-frequency interpulse (HFIP) emission pattern of the Crab pulsar, suggesting that the emission bands are actually diffraction fringes influenced by the pulsar's magnetosphere acting as a diffraction screen.
- - The model accounts for specific features like band spacing, high polarization, and a constant position angle, effectively enabling the "tomography" of the pulsar's magnetosphere and directly revealing its plasma density profile.
- - The model is designed to be testable with future predictions made, and it proposes a connection between the observed "high-frequency components" and the HFIP emissions.
Combined plasma lens and rephasing stage for a laser wakefield accelerator.
Sci Rep
November 2024
Department of Physics, Lund University, P.O. Box 118, Lund, 22100, Sweden.
Electrons from a laser wakefield accelerator have a limited energy gain due to dephasing and are prone to emittance growth, causing a large divergence. In this paper, we experimentally show that adjusting the plasma density profile can address both issues. Shock-assisted ionisation injection is used to produce 100 MeV quasi-monoenergetic electron bunches in the primary part of the accelerator.
View Article and Find Full Text PDFFrequency linearization of voltage controlled oscillator (VCO) for 2 µs frequency modulated continuous wave (FMCW) reflectometer.
Rev Sci Instrum
October 2024
Korea Institute of Fusion Energy, Daejeon 34133, South Korea.
Frequency modulated continuous wave reflectometers have been widely used to measure plasma density profiles in many magnetic fusion devices. The frequency modulation (FM) time of the KSTAR reflectometer was 20 µs, that is, the FM rate was 50 kHz. However, the edge density of the KSTAR tokamak fluctuates typically over the frequency range of 20-50 kHz in the ELMy H-mode plasmas.
View Article and Find Full Text PDFA Second-Harmonic Dispersion Interferometer (SHDI) is assembled to measure the two-dimensional, line-integrated density profile of a pulsed-plasma jet using probe-beam diameters well beyond the 1 mm diameters typically used in such instruments. An initial prototype demonstrated the technique using 7 mm beam diameters, which are now increased to 35 mm diameter using two types of beam expanders: an achromatic-beam expander (ABE) or a reflective-beam expander (RBE). ABEs were found to add a periodic background to the measured-phase image with a magnitude of the order of Δϕ ∼ 2π radians, compared to the background phase noise level in the system configured without beam expanders at Δϕbg ∼ 0.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!