Laser plume spectroscopy. 1. Graphite target

Abstract

We apply canonical Poisson-Lie T-duality transformations to bosonic open string worldsheet boundary conditions, showing that the form of these conditions is invariant at the classical level, and therefore they are compatible with Poisson-Lie T-duality. In particular the conditions for conformal invariance are automatically preserved, rendering also the dual model conformal. The boundary conditions are defined in terms of a gluing matrix which encodes the properties of D-branes, and we derive the duality map for this matrix. We demonstrate explicitly the implications of this map for D-branes in two non-Abelian Drinfel'd doubles.

Research of Discharge and Generation of Fast Electrons in Atmospheric Pressure Inhomogeneous Gas Media

“…The plume had following parameters: length -0.5 cm, area of 0.1 cm 2 temperature -equal to temperature of graphite sublimation (4500 K), concentration of neutral particles N < 0.1N L (N L -Loschmidt number). Such parameters can be easily received with the help of pulsed CO 2 laser [4]. Between the laser plume and anode was the air gap (N = N L ) with varied length.…”

From the Laser Plume to the Laser Ceramics

“…This model is confirmed by the fact that the delay time for the appearance of a laser flare from the beginning of the laser pulse exposure has a large spread and on average increases with increasing transparency of the target. In particular, the delay in the appearance of a laser plume on the surface of a semitransparent Nd:Y 2 O 3 ceramic with α = 23 cm −1 (an analog of the fused layer) averaged over several radiation pulses was 5-10 times greater than for the original sintered micro-powder target (α = 1.7 × 10 3 cm −1 ) at the same radiation intensity I = 0.4 MW/cm 2 [31]. The spread of the delay in the formation of a laser plume during evaporation of the same target is due to the stochastic nature of the depth of defects from the target surface at different points.…”

“…The nanoparticles are formed in a laser plume. A laser plume is a flow of incandescent vapors of a solid target in the form of a weakly ionized plasma from the region of incidence of the laser beam on the target [30,31]. In visible light, the plume is typically in the shape of a needle directed normal to the target surface, regardless of the angle of incidence of the laser beam ( Figure 2).…”

“…Over the entire length of the plume, its emission spectrum is represented by dominated structured molecular bands of radicals of cations of the target substance [31] against the background of a continuous band of recombination radiation (Figure 3). In this case, the short-wave part of the spectrum is well approximated by the Wien's curve, which makes it possible to determine the temperature of From the Laser Plume to the Laser Ceramics DOI: http://dx.doi.org/10.5772/intechopen.94464 the luminous gas in the flare.…”

“…The spectrum of the plume glow from a CO 2 laser at different distances (l) from the target of yttriumstabilized zirconium oxide (solid curve), recombination radiation (bold curve), and approximation of the Wien's curve (dashed line)[31].…”