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Roig, R. A.

Publications and source records attributed to Roig, R. A..

12 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Experimental transition probabilities and Stark-broadening parameters of neutral and single ionized tin

Strengths and Stark-effect widths of the Sn I and Sn II lines prominent between 3200 and 7900 A are measured with a spectroscopic shock tube. Absolute strengths of 17 ionic lines are obtained with estimated (22-50)% accuracy and conform to appropriate quantum-mechanical sum rules. Relative transition probabilities for nine prominent neutral tin lines, normalized to radiative-lifetime data, are compared with other experiments and theoretical predictions. Parameters for Stark-effect broadening are measured over a range of plasma electron densities. Broadening data (with accuracies of 15-35%) for one neutral and ten ionic lines of tin are compared to theoretical predictions.

Miller, M. H.↗
NASA NTRS1977

Stark shift in ionized boron

Stark shift of the B II line at 3451 A due to plasma microfields was measured in a luminous shock tube. Line profiles, photographically recorded in second order, were compared with closeby wavelength fiduciaries from low-pressure rare-gas lamps. Electron densities for each exposure were found by fitting H-beta profiles to theoretical line shapes. Results, estimated reliable to 25-30%, are compared with theoretical predictions.

Miller, M. H.↗
NASA NTRS1976

The absorption spectrum of neutral boron, B I

The absorption spectrum of B I has been studied in the 900-2000 A wavelength range by the flash pyrolysis technique. Transitions were observed from both the 2s(2)2p 2P ground state and the 2s2p2 4P metastable state. Five new quartet terms have been identified, with improved values obtained for two previously identified terms. A method of focusing has been developed, allowing the Ballofet-Romand-Vodar (1961) source to be used as a source of single-shot continuum in the lower wavelengths (300-1200 A) of the normal incidence region.

Roig, R. A.↗
NASA NTRS1975

The photoionization spectrum of neutral aluminium, Al I

The absorption spectrum of Al I has been studied for the wavelength range 1160 to 2000 A by the flash pyrolysis technique. Wavelengths and derived energy levels are reported for 70 new lines converging on the 3s3p(3)P(0) limits of Al II. The autoionization parameters of the 3p(2)P(0)-3p(2)(2)S doublet have been measured. Good agreement is obtained with the experiment of Kohl and Parkinson and the recent calculation of Le Dourneuf et al. The relative photoionization cross section has been measured in the wavelength region 1200 A to 2000 A.

Roig, R. A.↗
NASA NTRS1975

Extensions to the spectrum of singly ionized barium /Ba II/

The spectrum of singly ionized barium has been studied in absorption by flash pyrolysis. Corrected wavelengths and energy levels have been obtained. Fifteen new levels have been established and 24 new lines have been observed. Photoionization is shown to be the dominant ionization mechanism in this technique.

Roig, R. A.↗
NASA NTRS1974

Relative transition probabilities of cobalt

Results of determinations of neutral-cobalt transition probabilities measured relative to Co I 4150.43 A and Co II 4145.15 A, using a gas-driven shock tube as the spectroscopic light source. Results are presented for 139 Co I lines in the range from 3940 to 6640 A and 11 Co II lines in the range from 3840 to 4730 A, which are estimated to have reliabilities ranging from 8 to 50%.

Roig, R. A.↗
NASA NTRS1974

Absolute line strengths for carbon and sulfur

Work has been conducted to reduce substantially uncertainties concerning the line strengths for carbon and sulfur. Two or more independent methods were used to measure thermodynamic variables and to calibrate detectors for absolute sensitivity and spectral response. The absolute transition probabilities of 124 visible and infrared lines of C I, S I, and S II were measured in a consistent way.

Miller, M. H.↗
NASA NTRS1972

Relative transition probabilities for krypton.

First experimental line strength data for the visible Kr II lines and for several of the more prominent Kr I lines are given. The spectroscopic light source used is the thermal plasma behind the reflected shock wave in a gas-driven shock tube. A 3/4-m spectrograph and a 1-m spectrograph were employed simultaneously to provide redundant photometry. The data are compared with other measurements and with theoretical calculations.

Miller, M. H.↗
NASA NTRS1971

Absolute transition probabilities of phosphorus.

Use of a gas-driven shock tube to measure the absolute strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-

Miller, M. H.↗