Numerical 1D PIC-simulations of ion acceleration during laser-plasma interaction: Optimization of a two-component multil
- PDF / 211,540 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 65 Downloads / 143 Views
PHYSICS
Numerical 1D PICSimulations of Ion Acceleration during Laser–Plasma Interaction: Optimization of a TwoComponent Multilayered Target Structure I. A. Sidorova and A. B. Savel’evb a
Prokhorov Institute of General Physics, Russian Academy of Sciences, ul. Vavilova 38, Moscow, 119991 Russia b Moscow State University, Moscow, 119992 Russia Received December 11, 2008
Abstract—Ion beam acceleration is simulated using a onedimensional 1D2P PIC code. The dependences of the maximum energy and width of the energy spectrum of the generated ion beams on the duration and intensity of laser radiation, as well as on the target parameters (thickness and number of layers, types and den sities of atoms), are investigated. The optimal target configuration at which the energy of the accelerated ions is maximum (5–160 MeV for intensities of 5 × 1018–5 × 1020 W/cm2) is found. The optimal target configu ration is shown to depend on the intensity and be independent of the laser pulse duration. DOI: 10.1134/S1063780X10130040
1. INTRODUCTION Laser radiation intensities higher than 2 × 1022 W/cm2 [1], which have been achieved in recent years, made it possible to obtain a number of challeng ing results in experiments on the generation of high energy ion beams in the course of irradiation of thin foils with intense laser radiation. This method provides for highly efficient transfer of the laser beam energy to ions and the generation of ion beams with small angu lar divergences and diameters. The results of the performed experiments show that the energy of the generated ion beams substantially increases, provided that more intense radiation with shorter pulses is used [2–4]. The energies of ion beams, reached in recent experiments, were several hundreds of MeV [5]. At the same time, the angular divergence of the beam can be small (4 × 10–3 mm mrad) [2]; this makes beams obtained in this way a worthy alternative to the beams generated in particle accelerators. Highenergy ion beams can find wide application as injectors for ion accelerators [6] and can be used in such fields as ion radiotherapy of malignant tumors [7], production of radioisotopes for medical applica tions [8], neutron spectroscopy [9], visualization of electromagnetic fields [10], and the initiation of ther monuclear reactions. Moreover, it is extremely impor tant that the beams be not only highenergy, but also monochromatic. The most vital problem for the efficient application of ion beams is optimization of experimental condi tions with the aim of attaining the required beam char acteristics.
Theoretical and experimental investigations of dif ferent mechanisms, responsible for ion acceleration, showed that the dominant mechanism for intensities on the order of 1018–1020 W/cm2 is RSA (rearsurface acceleration), i.e., acceleration of ions by the electric field of separation of the charges, formed by the emit ted hot electrons on the rear surface of the target [11– 14]. For this mechanism to be efficiently imple mented, the targets should be as thin as
Data Loading...
