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Fast ion generation by a picosecond high-power laser

Badziak J., Parys P., Wołowski J., Hora H., Krasa J., Laska L., Rohlena K.

Optica Applicata

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2005

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Vol. 35, nr 1

5-22

EN

Recent progress in ultrashot-pulse high-power laser technology has resulted in the production of exstremely high light intensities aproaching 1020 W / cm2. The great non-linear forces generated by the laser pulse during its interaction with plasma can be used to accelerate electrons and ions to energies from hundreds of keV to hundreds of MeV over distances of only microns. This creates the prospect of construction of compact laser-based particle acceleraton rs and thier application in material science, medicine, nuclear physics, and inerial confinement fusion. In this paper, the results of our recent studies on fast ion generation in plasma produced by an intense 1-ps laser pulse, performed using the terawatt Nd:glass laser at Institute of Plasma Physics and Laser Microfusion (IPPLM) in Warsaw, are briefly reviewed. The properties of fast proton beams generated from thin foil targets of various structures as well as the heavy ion fluxes emitted from massive high-Z targets are discussed. The possibility of producing picosecond ion beams of ultrahigh ion current densities (1010 A/cm2 close to the target) is considered. The most important features of fast ion generation in the plasmas produced by ultrashort ( 1 ps ) and long ( 0.5 ns ) laser pulses are also compared.

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Effect of a laser beam focus position on ion emission from plasmas produced by picosecond and sub-nanosecond laser pulses from solid targets.

Woryna E., Badziak J., Makowski J., Parys P., Wołowski J., Krasa J., Laska L., Rohlena K., Vankov A.B.

Optica Applicata

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2001

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Vol. 31, nr 4

791-798

EN

The dependences of parameters of laser-produced ion fluxes on the laser focus position with respect to the target surface for picosecond laser pulses are presented and compared with the ones for sub-nanosecond pulses at nearly the same densities of laser energy. The experiments were performed with the use of chirped-pulse-amplification Nd:glass laser system. Thick Au targets were irradiated by normally incident laser pulses. The maximum intensities of the focused laser beams were 8 * 10/sup 16/ and 2 * 10/sup 14/ W/cm/sup 2/ for ps and sub-ns laser pulses, respectively. The particle fluxes were analysed with the use of ion collectors and an electrostatic ion-energy analyser. The ion current densities and the charges carried by ions as well as the maximum and peak velocities of fast and thermal ion groups as a function of the focus position for ps and sub-ns pulses were determined.

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Laser ion sources for various applications.

Wołowski J., Parys P., Woryna E., Krasa J., Laska L., Rohlena K.

Optica Applicata

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2000

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Vol. 30, nr 1

69-82

EN

Presents the results of studies of ion emission from the high-Z plasma generated using short wavelength, short pulse lasers: Nd:glass laser at the IPPLM in Warsaw and iodine laser PERUN at the IP ASCR in Prague. These studies were motivated mainly by the laser-produced plasma applications as a heavy ion source for particle accelerators and for ion implantation. The properties of highly charged ion streams were investigated by ion diagnostic methods: ion collectors and a cylindrical electrostatic energy analyzer. The results proved the existence of highly charged ions with charges 2[right angle bracket]40 (measured z/sub max/=55 for Ta) and with energies of several MeV in a far expansion zone. Ion current densities higher than 20 mA/cm/sup 2/ at about 1 m from the target were demonstrated. Construction of an effective laser heavy ion source seems thus to be not a principal, but rather a technological problem. ECLISE experiment (ECR ion source coupled to a laser ion source for charge state enhancement) has been founded by INFN LNS in Catania and preliminary experiments have been carried out at the IPPLM in Warsaw, in order to confirm the beneficial effects of the axial magnetic field of the ECR ion source on the extraction of ions from the LIS, and to evaluate the ion energy, which is the critical parameter for the coupling process. Direct implantation of ions from laser produced plasma has been investigated using the PERUN laser system at the IP ASCR in Prague. Attention was devoted mainly to the properties of the ion streams from the laser-produced plasmas (Sn, Pb, Ag) as well as to the direct implantation of those ions into different materials.