Carbon Nanotube Formation: C2 Swan Band Emissions For Various Ablation Laser Combinations Carmen Range LeTourneau University Longview, TX NASA Johnson Space Center Thermal Branch Structures and Mechanics Division Engineering.
Download ReportTranscript Carbon Nanotube Formation: C2 Swan Band Emissions For Various Ablation Laser Combinations Carmen Range LeTourneau University Longview, TX NASA Johnson Space Center Thermal Branch Structures and Mechanics Division Engineering.
Carbon Nanotube Formation: C2 Swan Band Emissions For Various Ablation Laser Combinations Carmen Range LeTourneau University Longview, TX NASA Johnson Space Center Thermal Branch Structures and Mechanics Division Engineering Directorate Increase Production of Carbon Nanotubes modify current methods or design new methods Understand the chemical mechanism Laser Ablation target tube Previous Work Based on Laser Induced Fluorescence Detector Optics Laser Sample C2 LIF Previous Results C2 LIF Previous Results Ni LIF Experimental Setup Monochromator disperses emmision onto an ICCD Emission Collected by a Fiber Optic Ablation Lasers Graphite Target Various combinations involving 3 ablation lasers C2 Energy Levels 2 d3Pg 1 '=0 20023 cm-1 4 a3 P 3 u 2 1 '=0 X1Su+ 0 cm-1 Vibrational Bands Vibrational Bands Δv = 0 Baseline Variations Baseline Variations Baseline Variations File Lasers Modified Fit Unmodified Fit 00jan21e IR Gr Gr 9600 K 9600 K 00jan6e Gr Gr IR 9600 K 9600 K 99dec20e IR Gr IR 8800 K 8800 K 99dec22f IR IR Gr 8600 K 8800 K 00jan21h IR Gr Gr 8000 K 8300 K 00jan6h Gr Gr IR 7600 K 8100 K 99dec22h IR IR Gr 7900 K 8000 K 00jan6g Gr Gr IR 7800 K 8000 K 00jan21g IR Gr Gr 7800 K 7900 K 99dec22i IR IR GR 7800 K 7900 K 99dec20g IR Gr IR 7700 K 7800 K 99dec20h IR Gr IR 7600 K 7700 K Trends in Temperature Trends in Temperature Temperature Fits Temperature Fits Temperature Fits Delay Slit Width Ratio of Δv = 1&0 Ratio of Δv = 1 & -1 IR Gr Gr 1500 100 9600 K 6500 K 00jan6e Gr Gr IR 1500 100 9600 K 6300 K 99dec20e IR Gr IR 1500 100 8800 K 6000 K 99dec22f IR IR Gr 1500 100 8800 K 5900 K 00jan21h IR Gr Gr 5000 500 8300 K 5900 K 00jan6h Gr Gr IR 5000 500 8100 K 5900 K 00jan6g Gr Gr IR 5000 100 8000 K 6200 K 99dec22h IR IR Gr 5000 100 8000 K 6400 K 00jan21g IR Gr Gr 5000 100 7900 K 6200 K 99dec22i IR IR Gr 5000 500 7900 K 5800 K 99dec20g IR Gr IR 5000 100 7800 K 6000 K 99dec20h IR Gr IR 5000 500 7700 K 5800 K File Lasers 00jan21e Conclusions • Different ablation laser combinations result in different C2 emmission spectra. • Shorter wavelength lasers result in spectra with greater intensity and warmer temperatures. • Fitting is complicated by a broad underlying contribution of uncertain origin. • Spectra does not appear to fit well to a single temperature. Future Work • Further analysis of the 3 laser spectra. • Analysis of data from Parametric Studies. • Computational modeling for: – nanotube behavior and properties – molecular intermediates Acknowledgement Carl Scott Sivaram Arepalli William Holmes Pasha Nikolaev Brad Files SFF NASA-ASEE