skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Two-dimensional fluorescence spectroscopy of laser-produced plasmas

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1267537
Grant/Contract Number:
NA 22; AC05-76RL01830
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Optics Letters
Additional Journal Information:
Journal Volume: 41; Journal Issue: 15; Related Information: CHORUS Timestamp: 2016-07-21 17:02:38; Journal ID: ISSN 0146-9592
Publisher:
Optical Society of America
Country of Publication:
United States
Language:
English

Citation Formats

Harilal, S. S., LaHaye, N. L., and Phillips, M. C.. Two-dimensional fluorescence spectroscopy of laser-produced plasmas. United States: N. p., 2016. Web. doi:10.1364/OL.41.003547.
Harilal, S. S., LaHaye, N. L., & Phillips, M. C.. Two-dimensional fluorescence spectroscopy of laser-produced plasmas. United States. doi:10.1364/OL.41.003547.
Harilal, S. S., LaHaye, N. L., and Phillips, M. C.. 2016. "Two-dimensional fluorescence spectroscopy of laser-produced plasmas". United States. doi:10.1364/OL.41.003547.
@article{osti_1267537,
title = {Two-dimensional fluorescence spectroscopy of laser-produced plasmas},
author = {Harilal, S. S. and LaHaye, N. L. and Phillips, M. C.},
abstractNote = {},
doi = {10.1364/OL.41.003547},
journal = {Optics Letters},
number = 15,
volume = 41,
place = {United States},
year = 2016,
month = 7
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1364/OL.41.003547

Citation Metrics:
Cited by: 4works
Citation information provided by
Web of Science

Save / Share:
  • We use a two-dimensional laser-induced fluorescence spectroscopy technique to measure the coupled absorption and emission properties of atomic species in plasmas produced via laser ablation of solid aluminum targets at atmospheric pressure. Emission spectra from the Al I 394.4 nm and Al I 396.15 nm transitions are measured while a frequency-doubled, continuous-wave, Ti:Sapphire laser is tuned across the Al I 396.15 nm transition. The resulting two-dimensional spectra show the energy coupling between the two transitions via increased emission intensity for both transitions during resonant absorption of the continuous-wave laser at one transition. Time-delayed and gated detection of the emission spectrummore » is used to isolate the resonantly-excited fluorescence emission from the thermally-excited emission from the plasma. In addition, the tunable continuous-wave laser measures the absorption spectrum of the Al transition with ultra-high resolution after the plasma has cooled, resulting in narrower spectral linewidths than observed in emission spectra. Our results highlight that fluorescence spectroscopy employing continuous-wave laser re-excitation after pulsed laser ablation combines benefits of both traditional emission and absorption spectroscopic methods.« less
  • We present fluorescence spectroscopy of selected Al transitions in a laser produced plasma at atmospheric pressure levels.
  • Various characteristics of x-ray emission from laser plasmas produced by a picosecond YAG laser (where YAG represents yttrium aluminum garnet) are investigated in the wide wavelength band ranging from 10 to 2000 A from the point of view that emitted radiation from laser plasmas is applied to many purposes, such as laser fusion, x-ray lasers, x-ray sources, and solid-state physics. In this wide wavelength band, extremely different dependences of x-ray energies on input laser energies are made clear. With a decrease of the wavelength, the slope of the dependences increases. Decay times of emitted x-rays from laser plasmas are approximatelymore » proportional to the wavelengths. Computational studies are also performed in the framework of a transient collisional radiative model in order to explain the experimental results.« less
  • A thermally assisted laser-induced fluorescence (LIF) detection system is developed to measure two-dimensional spatial profiles of number density of alkali atoms seeded in an open-cycle MHD generator, especially in the boundary layer on channel electrodes. The spatial resolution of this system is evaluated to be 1.3 mm. To assess the system, the LIF intensity from Na atoms used as a seed tracer is measured in a laminar air-acetylene flame. The detected spatial profiles of the intensity show good agreement with those of the number density of sodium atoms measured by the spectral line absorption method. The LIF intensity near themore » surface of a cooled metal piece placed in the acetylene flame is also measured with this system as a preliminary experiment for applying it to the boundary layer on MHD channel electrodes.« less
  • We present the development and application of a diagnostic system for the analysis of microwave generated low-pressure plasmas, which might also be used for the investigation of the edge regions in magnetically confined fusion plasmas. Our method uses planar laser-induced fluorescence, which is produced by excitation of neutral metastable atoms through a short, intense, pulsed laser. The beam expansion optics consist of an uncommon setup of four lenses. By controlled shifting of an element of the optics sideways, the location of the laser sheet in the plasma is scanned perpendicular to the excitation plane. Together with a spectrometer observing differentmore » observation volumes along the beam path, we are able to map absolute three-dimensional (3D) population density distributions of the metastable ({sup 2}P{sub 1/2}{sup o}) 3s[1/2]{sub 0}{sup o} state of Ne I in an electron cyclotron resonance heating (ECRH) plasma. This optical tomography system was used to study the influence of the microwave power and mode on the spatial structure of the plasma. The results show that the population density of the neutral neon in this metastable state is found to be in the range of 10{sup 16} m{sup -3}, and that its spatial distribution is associated with the 3D structure of the magnetic field. We also report that the spatial distribution strongly varies with the mode structure, which depends on the microwave power.« less