Abstract
The dynamics of a MeV laser-produced proton beam affected by a radio frequency (rf) electric field has been studied. The proton beam was emitted normal to the rear surface of a thin polyimide target irradiated with an ultrashort pulsed laser with a power density of 4×1018 W/cm2. The energy spread was compressed to less than 11% at the full width at half maximum (FWHM) by an rf field. Focusing and defocusing effects of the transverse direction were also observed. These effects were analyzed and reproduced by Monte Carlo simulations. The simulation results show that the transversely focused protons had a broad continuous spectrum, while the peaks in the proton spectrum were defocused. Based on this new information, we propose that elimination of the continuous energy component of laser-produced protons is possible by utilizing a focal length difference between the continuous spectral protons and the protons included in the spectral peak.Received 15 June 2007DOI:https://doi.org/10.1103/PhysRevSTAB.12.063501This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Highlights
An increase in the acceleration gradient of chargedparticle beams has long been required for fundamental researches, such as particle and nuclear physics, in order to obtain high-energy particles within a limited length of the accelerators
The simulation results show that the transversely focused protons had a broad continuous spectrum, while the peaks in the proton spectrum were defocused. Based on this new information, we propose that elimination of the continuous energy component of laser-produced protons is possible by utilizing a focal length difference between the continuous spectral protons and the protons included in the spectral peak
The laser pulse was focused by an off-axis parabolic mirror with a focal length of 325 mm, and the focused energy was 0.45 J on a 7:5 m-thick polyimide tape target giving an intensity of 4 Â 1018 W=cm2 on the target
Summary
An increase in the acceleration gradient of chargedparticle beams has long been required for fundamental researches, such as particle and nuclear physics, in order to obtain high-energy particles within a limited length of the accelerators. The emission of energetic ions from a plasma created by a high-intensity short-pulse laser has been reported [1,2]. In order to produce monoenergetic ion beams with high repetition-rate operation, we have pro-. Posed the combination of laser-plasma acceleration with a phase-rotation method by a synchronous rf electric field [18,19,20,21]. If the phase of the rf field is adjusted so that the earlier arrived ions are decelerated and the ions arriving later are accelerated, we can collect the ions to a certain energy region. The dynamics of laser-produced proton beams (with a broad energy spectrum) was studied by applying an rf electric field in both experiments and (computer situations) calculations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Physical Review Special Topics - Accelerators and Beams
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
