Tantalum ions produced by 1064 nm pulsed laser irradiation

Abstract

All-boron analogues of aromatic hydrocarbons: B17− and B18− J. Chem. Phys. 134, 224304 (2011) On the simulation of photoelectron spectra complicated by conical intersections: Higher-order effects and hot bands in the photoelectron spectrum of triazolide (CH)2N3− J. Chem. Phys. 134, 184314 (2011) Time-resolved photoelectron spectroscopy of coupled electron-nuclear motion J. Chem. Phys. 134, 184307 (2011) Photoelectron angular distributions from autoionizing 4s14p66p1 states in atomic krypton probed with femtosecond time resolution A Q-switched Nd:YAG ͑yttrium aluminum garnet͒ laser ͑1064 nm wavelength͒ with a 9 ns pulse width, 1-900 mJ pulse energy, and 0.5 mm 2 target spot, is employed to irradiate tantalum targets in vacuum. The irradiation produces a strong etching of the metal and forms a plasma in front of the target. The plasma contains neutrals and ions with a high charge state and a wide energy distribution. Time-of-flight measurements are presented for the ionic production. A cylindrical electrostatic ion analyzer permits to measure the yield and the charge state of the emitted ions and to extrapolate the ion energy distribution as a function of the laser fluence in the range 10-100 J/cm 2 . The measurements indicate that at high laser fluence the tantalum charge state may reach 8ϩ and the maximum ion energy about 6 keV. The ion energy distribution is presented as a function of the charge state. It follows approximately a ''shifted Maxwellian distribution.'' A better theoretical approach has been further developed considering the Coulomb interactions occurring inside the plasma, which produce ion acceleration at velocities comparable with thermal ones, according to the so-called ''shifted Maxwellian-Coulombian distribution.''

MeV ion beams generated by intense pulsed laser monitored by Silicon Carbide detectors

“…Carbon ion contaminations might also be present. The spectrum reported in Fig.2b was fitted with the Coulomb-Boltzmann-shifted (CBS) function, which allows to deconvolve the experimental spectrum in the different ion species and charge states contributions [13]. The CBS function takes into account thermal and Coulomb interactions between plasma particles.…”

Caracterización de las Distribuciones de Energía Cinética en los Iones Producidos por Ablación Láser de Metales

“…El espectro está lo suficientemente resuelto como para que se distingan los dos isótopos del Cu de masas 63 y 65 u.m.a., con una relación entre las intensidades de ambos similar a la que se recoge en la bibliografía (69% y 31% respectivamente) (Lide, 2006). Los iones se expulsan del metal con energías cinéticas que se ajustan experimentalmente a distribuciones de Maxwell-Boltzmann, con una componente de velocidad debida a la repulsión entre cargas (Torrisi et al, 2002). Estas distribuciones se conocen como de Maxwell-Boltzmann-Coulomb (MBC):…”

Magnetic and electric deflector spectrometers for ion emission analysis from laser generated plasma

“…Changing the bias voltage V it is possible to change the E/z ratio and to have information about the ion energy distributions. For example Boltzmann ion distributions emitted from hot plasma were detected according to previous papers [7,8]. An example of magnetic deflector is represented by the system used in our laboratory to separate the different mass-to-charge ratio using the horizontal ion deflection produced by a magnetic field of the order of 0.3 T with a length of 1 cm orthogonal to the input direction of ions accelerated from the laser generated plasma.…”