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Studies of ion fluxes emitted from picosecond and nanosecond laser-produced plasmas

Badziak J., Parys P., Wołowski J., Woryna E.

Journal of Technical Physics

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2004

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Vol. 45, no 1

3-20

EN

Energetic ions emitted from plasmas produced by the interaction of intense laser pulses with solid targets are currently a subject of growing interest due to the possibility of unique applications in accelerator technology, nuclear physics, material science and medicine. Depending on the kind of application, different parameters of the ion fluxes are required, and various conditions of laser-target interaction must be considered. In this paper, selected results of our recent studies of ion emission from plasmas produced by laser pulses of duration from ~ 1 ps to ~ 1 ns and of intensities from 10^10 W/cm^2 to 10^17 W/cm^2 are reviewed. The characteristics of both heavy ion fluxes emitted from massive high-Z targets and proton beams generated from thin foil targets of various structures are presented. Some basic properties of ion fluxes produced in various experimental conditions are discussed. The effect of external magnetic field on the ion emission is demonstrated.

2

X-ray emission from high-intensity interaction of picosecond and subnanosecond laser pulses with solid targets

Badziak J., Jabłoński S., Makowski J., Parys P., Ryć L., Vankov A.B., Wołowski J., Woryna E.

Optica Applicata

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2002

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Vol. 32, nr 1-2

41-46

EN

The results of comparison of X-ray emission from plasmas produced by 1-ps and 0.5-ns laser pulses from massive and foil targets are reported. The measurements were performed for the soft (0.8-1.6 keV) and hard (4-30 keV) X-rays with the use of filtered p-i-n Si photodiodes at laser intensities of up to 10/sup 17/ W/cm/sup 2/ for ps pulses and up to 3 * 10/sup 14/ W/cm/sup 2/ for sub-ns ones. The effect of the laser pulse duration on the X-ray yields for various laser beam focal spots, laser pulse energies and atomic numbers of the targets were investigated.

3

Studies of plasma and craters produced by the interaction of high-energy sub-nanosecond laser with silver target

Woryna E., Badziak J., Parys P., Suchańska R., Wołowski J., Krása J., Láska L., Pfeifer M., Rohlena K., Ullschmied J.

Nukleonika

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2002

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Vol. 47, nr 4

147-150

EN

The results of measurements of microablation from a silver target irradiated by the high-power PALS laser system in Prague are presented. In this experiment the laser beam of energy of about 110 J in a 400 ps pulse was focused perpendicularly to the massive silver target. The target surface position was changed with respect to the focal spot of the laser beam in the range from -2.5 to 2.5 mm. A set of four ion collectors was used for plasma ion emission measurements. The effect of the laser pulse interaction with the target, i.e. craters and damages formed in the vicinity of the craters, were investigated with the use of scanning electron microscopy (SEM) and optical microscopy methods. The characteristics of the crater were compared with the essential parameters of ion streams emitted from the plasma produced in the same laser shot.

4

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.

5

Laser-produced plasma for simulation of plasma jets propagation in geoplasma.

Wołowski J., Parys P., Woryna E., Zakharov Y.P., Orishich A.M., Eremin A.V.

Optica Applicata

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2000

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Vol. 30, nr 1

61-67

EN

This work presents the results concerning dynamics of laser-produced plasma streams from a flat target placed in a transverse magnetic field of B/sub 0/[left angle bracket]0.9 T which were obtained during joint experiments carried out at IPPLM. They include data about main stages of plasma-field interaction, creation of the diamagnetic cavity, plasma deceleration and heating, and transformation of kinetic energy into electromagnetic one. Institution

6

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.

7

High-intensity interaction of picosecond laser pulses with metal target.

Badziak J., Makowski J., Parys P., Ryć L., Wołowski J., Woryna E., Vankov A.

Optica Applicata

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2000

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Vol. 30, nr 1

83-92

EN

The results of experimental investigation of the interaction of picosecond light pulses with a Cu target at light intensities up to 3.10/sup 16/ W/cm/sup 2/ are presented and discussed. The experiment was performed with the use of a terawatt chirped-pulse-amplification Nd:glass laser and the apparatus for corpuscular (ion collectors, electrostatic ion energy analyser) and X-ray (p-i-n Si photodiode) diagnostics of laser-produced plasma. The charge spectra of ions emitted from a picosecond plasma as well as the energy-dependent (or intensity-dependent) characteristics of ion emission and soft X-ray yield are determined. The electron temperature and the average charge state of the plasma are evaluated as a function of light intensity.

8

Reflection of ultra-intense picosecond light pulse from metal target.

Badziak J., Makowski J., Parys P., Woryna E.

Optica Applicata

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1999

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Vol. 29, nr 3

393-399

EN

The dependence of specular reflectivity of a picosecond ligh pulse from a metal (Cu) target - placed perpendicularly to direction of incident light -on the light intensity in the intensity range 3x10 14 - 3x10 16 W/cm is investigated experimentally. It has been found that , contrary to the experiments with high-contrast femtosecond pulses, the reflectivity decreases as light intensity increases to the value ~7x10 15 W/cm2, and above this intensity the value of the reflectivity is provided, assuming that the interaction of the main picosecond pulse with the target is modifield by a short-lasting (<1 ns) prepulse producing an expanding preplasma on the target surface.