Emission Mechanisms of Continuous Radiation

Variation of the amount of hydrogen along the galactic ridge

Symposium - International Astronomical Union ◽

10.1017/s0074180900100889 ◽

1967 ◽

Vol 31 ◽

pp. 171-172

Author(s):

Th. Schmidt-Kaler

Keyword(s):

Surface Brightness ◽

Milky Way ◽

Neutral Hydrogen ◽

Line Of Sight ◽

Optical Surface ◽

Hydrogen Density ◽

Continuous Radiation ◽

Galactic Longitude

The integralNHof neutral-hydrogen density along the line of sight is determined from the Kootwijk and Sydney surveys. The run ofNHwith galactic longitude agrees well with that of thermal continuous radiation and that of the optical surface brightness of the Milky Way.

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Nanosecond laser-induced breakdown assisted by femtosecond laser pre-ionization in air: the effect on spatial resolution and continuous radiation

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200258 ◽

2020 ◽

Vol 92 (2) ◽

pp. 20701

Author(s):

Bo Li ◽

Xiaofeng Li ◽

Zhifeng Zhu ◽

Qiang Gao

Keyword(s):

Femtosecond Laser ◽

Spatial Resolution ◽

Laser Induced Breakdown Spectroscopy ◽

Nanosecond Laser ◽

Breakdown Threshold ◽

Powerful Technique ◽

Breakdown Spectroscopy ◽

Continuous Radiation ◽

Laser Induced Breakdown

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.

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Determination of the profile of the temperature field of material heated by continuous laser radiation

Physics and Chemistry of Materials Treatment ◽

10.30791/0015-3214-2020-3-5-10 ◽

2020 ◽

pp. 51-10

Author(s):

B.A. Lapshinov ◽

◽

N.I. Timchenko ◽

Keyword(s):

Temperature Field ◽

Optical Fiber ◽

Prolonged Exposure ◽

Radiation Spectrum ◽

Visible Range ◽

Continuous Laser ◽

Surface Temperature Distribution ◽

Continuous Radiation ◽

Spectral Pyrometry

Spectral pyrometry was used to determine the surface temperature distribution of Si, Nb, Cu, and graphite samples when they were locally heated by continuous radiation of an Nd:YAG laser (λ = 1.064 μm). With prolonged exposure to radiation, a stationary temperature field was established in the samples. The thermal spectra were recorded with a small spectrometer in the visible range in the temperature range above 850 K. The optical fiber used to transmit the radiation spectrum to the spectrometer had an additional diaphragm with a diameter of 1 mm located at a certain distance from the fiber end, which ensured the locality of the recorded spectra. The optical fiber moved continuously along the sample, and the spectrometer recorded up to 100 spectra with a frequency of 5-10 Hz. The temperature profile of the samples was calculated based on the results of processing the spectra using the Spectral Pyrometry program.

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