Modification of materials by high energy plasma ions

none17The high-power iodine laser of the Prague Asterix Laser System (PALS), emitting radiation at 438 nm wavelength, 400 ps pulse duration and about 250 J maximum pulse energy, was employed to irradiate in vacuum a germanium target. The amount, the energy and the charge state of the ions emitted from the laser-produced plasma are analyzed by time-of-flight measurements performed with the use of ion collectors (ICs) and an electrostatic ion energy analyzer (IEA). Energetic Ge ions emitted from the laser-produced plasma were directly implanted into C substrates placed at 30 cm distance from the target and 30 degrees angle with respect to the normal to the target surface. The implantation depths and implanted doses were analyzed by two different techniques: the Rutherford backscattering spectrometry (RBS) and the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).Impact Factor 1.090A. LORUSSO; F. BELLONI; D. DORIA; V. NASSISI; J. WOLOWSKI; J. BADZIAK; P. PARYS; J. KRASA; L. LASKA; F. P. BOODY; L. TORRISI; A. MEZZASALMA; A. PICCIOTTO; S. GAMMINO; L. CALCAGNILE; G. QUARTA; D. BLEINERLorusso, Antonella; Belloni, Fabio; Doria, Domenico; Nassisi, Vincenzo; J., Wolowski; J., Badziak; P., Parys; J., Krasa; L., Laska; F. P., Boody; L., Torrisi; A., Mezzasalma; A., Picciotto; S., Gammino; Calcagnile, Lucio; Quarta, Gianluca; D., Bleine

The ALP-PALS Project: optimal coupling for laser propulsion

Since the early 1970s ablative laser propulsion (ALP) has promised to revolutionize space travel by reducing the 30:1 propellant/payload ratio needed for near-earth orbit by up to a factor of 50, by leaving the power source on the ground. But the necessary sub-ns high average power lasers were not available. Dramatic recent progress in laser diodes for pumping solid-state lasers is changing that. Recent results from military laser weapons R and D programs, combined with progress on ceramic disk lasers, suddenly promise lasers powerful enough for automobile-size, if not space shuttle-size payloads, not only the 4 - 10 kg "microsatellites" foreseen just a few years ago. For ALP, the 1.6-μm Er:YAG laser resonantly pumped by InP diode lasers is especially promising. Prior coupling experiments have demonstrated adequate coupling coefficients and specific impulses, but were done with too long pulses and too low pulse energies. The properties of ions produced and the ablated surface were generally not measured but are necessary for understanding and modeling propulsion properties. ALP-PALS will realistically measure ALP parameters using the Prague Asterix Laser System (PALS) high power photodissociation iodine laser (λ = 1.315 μm, EL ≤1 kJ, τ ~ 400 ps, beam diameter ~29 cm, flat beam profile) whose parameters match those required for application. PALS' 1.3-μm λ is a little short (vs. 1.53-1.72 μm) but is the closest available and PALS' 2ω / 3ω capability allows wavelength dependence to be studied

The ALP-PALS Project: optimal coupling for laser propulsion

Since the early 1970s ablative laser propulsion (ALP) has promised to revolutionize space travel by reducing the 30:1 propellant/payload ratio needed for near-earth orbit by up to a factor of 50, by leaving the power source on the ground. But the necessary sub-ns high average power lasers were not available. Dramatic recent progress in laser diodes for pumping solid-state lasers is changing that. Recent results from military laser weapons R and D programs, combined with progress on ceramic disk lasers, suddenly promise lasers powerful enough for automobile-size, if not space shuttle-size payloads, not only the 4 - 10 kg "microsatellites" foreseen just a few years ago. For ALP, the 1.6-μm Er:YAG laser resonantly pumped by InP diode lasers is especially promising. Prior coupling experiments have demonstrated adequate coupling coefficients and specific impulses, but were done with too long pulses and too low pulse energies. The properties of ions produced and the ablated surface were generally not measured but are necessary for understanding and modeling propulsion properties. ALP-PALS will realistically measure ALP parameters using the Prague Asterix Laser System (PALS) high power photodissociation iodine laser (λ = 1.315 μm, EL ≤1 kJ, τ ~ 400 ps, beam diameter ~29 cm, flat beam profile) whose parameters match those required for application. PALS' 1.3-μm λ is a little short (vs. 1.53-1.72 μm) but is the closest available and PALS' 2ω / 3ω capability allows wavelength dependence to be studied