Intense ion beams accelerated by ultra-intense laser pulses

• Published in: AIP conference proceedings pp. 199 - 209
• Main Authors: Roth, M, Cowan, T E, Gauthier, J C, Meyer-ter Vehn, J, Allen, M, Audebert, P, Blazevic, A, Fuchs, J, Geissel, M, Hegelich, M
• Format: Conference Proceeding
• Language: English
• Published: 01.01.2002
• ISSN: 0094-243X

The discovery of intense ion beams off solid targets irradiated by ultraintense laser pulses has become the subject of extensive international interest. These highly collimated, energetic beams of protons and heavy ions are strongly dependent on the laser parameters as well as on the properties of the irradiated targets. We have studied the influence of the target conditions on laser-accelerated ion beams generated by multi-terawatt lasers. The experiments were performed using the 100 TW laser facility at Laboratoire pour l'Utilisation des Laser Intense (LULI). The targets were irradiated by pulses up to 5 OE 10 exp 19 W/sq cm (300 fs, wavelength, 1.05 micron) at normal incidence. A strong dependence on the surface conditions, conductivity, shape, and purity was observed. The plasma density on the front and rear surface was determined by laser interferometry. We characterized the ion beam by means of magnetic spectrometers, radiochromic film, nuclear activation, and Thompson parabolas. The strong dependence of the ion beam acceleration on the conditions on the target back surface was confirmed, in agreement with predictions based on the target normal sheath acceleration (TNSA) mechanism. Finally, shaping of the ion beam has been demonstrated by the appropriate tailoring of the target. (Author)