Electronic temperature and density of the plasma produced by nanosecond ultraviolet laser ablation of LiF

Abstract

Optical emission spectroscopy is used to investigate the spatial evolution of the electron temperature (Te) and electron density (Ne) in the plasma generated by laser ablation in a vacuum of a wide-band-gap material, such as LiF, with a pulsed 193 nm excimer laser operating at a fluence of 1.5Jcm−2 close to the threshold. It is found that, whereas Ne (in the range of 1016cm−3) decreases by a factor of 2 as the distance to the target increases, Te exhibits a sharp decrease (from 1.85 eV to 0.66 eV) between 1 and 2 mm from the target and it remains practically constant for longer distances from the target. These results provide direct measurements of the electron temperature and density during nanosecond laser ablation of LiF.

Time resolved optical emission spectroscopy of cross-beam pulsed laser ablation on graphite targets

“…The aim of this work is to determine how the first plasma affects the second one as a function of the distance to the second pulse target. The plasma was assumed to be in local thermodynamic equilibrium (LTE); it was also assumed that the main broadening mechanism of the emission lines is the Stark effect [14][15][16][17].…”

Analisa Spektroskopi Emisi Untuk Penentuan Temperatur Elektronik Pada Plasma Non-Termik Nitrogen

“…Perkiraan temperature dari analisa spektrum emisi plasma nitrogen yang dibangkitkan dengan radio frekuensi mulai dari tekanan sangat rendah (0,1 mbar) sampai tekanan udara luar (1 bar) telah dilakukan oleh (Dinescu et al, 2005). Dengan menggunakan spekrum emisi temperature elektronik dan densitas elektronik dalam plasma LiF telah dilakukan pengukuran (Gordillo-Vázquez et al, 2005). Plasma LiF yang diteliti oleh Gordillo-Vázquez et al dibangkitkan dengan laser pulsa.…”

Laser-Induced Breakdown Spectroscopy (LIBS) Analysis of Laser Processing in Active Crystal with Nanosecond Laser Pulses

“…1–9 Not much work has been done using LIBS as an analytical technique for laser crystal characterization. 10 Thus, there are still many unanswered questions regarding the fundamental mechanisms underlying the nanosecond laser interaction with crystals. Gordillo-Vázquez et al 10 made a plasma characterization of lithium fluoride (an optical crystal) in vacuum conditions.…”

“…10 Thus, there are still many unanswered questions regarding the fundamental mechanisms underlying the nanosecond laser interaction with crystals. Gordillo-Vázquez et al 10 made a plasma characterization of lithium fluoride (an optical crystal) in vacuum conditions. However, they did not fully characterize the ablation process, i.e., they did not estimate a key parameter for laser processing such as the ablation threshold.…”