scholarly journals An experimental study of hydrogen line broadening in shock tubes.

1955 ◽  
Vol 60 ◽  
pp. 158 ◽  
Author(s):  
Lowell R. Doherty ◽  
Eugene B. Turner
Keyword(s):  
Experimental Study ◽  
Shock Tubes ◽  
Line Broadening ◽  
Hydrogen Line

scholarly journals Experimental study of line spectrum generation by argon dopant in DT-gas on ISKRA-5 facility

1999 ◽  
Vol 17 (3) ◽  
pp. 377-383 ◽  
Author(s):  
S.A. BEL'KOV ◽  
A.V. BESSARAB ◽  
A.V. VESELOV ◽  
V.A. GAIDACH ◽  
G.V. DOLGOLEVA ◽  
...  
Keyword(s):  
Experimental Study ◽  
Wall Thickness ◽  
Shell Thickness ◽  
Experimental Results ◽  
Line Broadening ◽  
X Ray ◽  
Radiation Spectra ◽  
Compressed Gas ◽  
Indirect Drive ◽  
Spectrum Generation

The experiments measuring the density of DT mixture compressed in indirect drive targets (X-ray targets) were conducted on the ISKRA-5 facility. The density was determined from the line broadening of H- and He-like Ar doped in DT-gas as a diagnostic substance. A series of three experiments with the X-ray targets having different shell thickness of capsule filled with DT + Ar mixture were carried out. In two of the three experiments, radiation spectra of Ar were recorded and the density of compressed gas was determined. The analysis of the experimental results for the X-ray target with a 280-μm diameter and a 7 μm wall thickness revealed that the density of the compressed gas may be estimated as ∼1 g/cm3.

scholarly journals Theoretical and experimental study of complete spectral series as a diagnostic tool for dense plasmas

1987 ◽  
Vol 5 (1) ◽  
pp. 155-162 ◽  
Author(s):  
B. d'Etat ◽  
J. Grumberg ◽  
E. Leboucher ◽  
H. Nguyen ◽  
A. Poquérusse
Keyword(s):  
Experimental Study ◽  
Diagnostic Tool ◽  
Stark Effect ◽  
High Density ◽  
Tunnel Effect ◽  
Spectral Series ◽  
Line Broadening ◽  
Dense Plasmas ◽  
Plasma Ions ◽  
Laser Plasmas

A theoretical and experimental study of line broadening and merging is presented and suggested for diagnosis of high density laser plasmas. For densities larger than 1022 cm−3 the hydrogenlike sequence is reduced to four lines for the emitter ion with ZE = 9. The perturbation effects on the latter come mainly from the interaction with plasma ions and electrons (Stark effect, multipolar interactions, ionization by tunnel effect, polarization line shift …).

scholarly journals Hydrogen Line Profiles

1995 ◽  
Vol 10 ◽  
pp. 411-414 ◽  
Author(s):  
I. Hubeny
Keyword(s):  
Transfer Problem ◽  
Current Status ◽  
Line Profiles ◽  
Line Broadening ◽  
Hydrogen Line ◽  
Radiative Transfer Problem ◽  
Frequency Redistribution ◽  
Sufficient Detail ◽  
High Degree ◽  
Complete Frequency

Observed hydrogen line profiles are an enormously important source of diagnostic information about virtually all kinds of astronomical bodies. Therefore, it is important to understand the hydrogen line formation in sufficient detail to be able to achieve a high degree of reliability by analyzing observed hydrogen line profiles.Calculation of the predicted hydrogen line profiles involves two basic ingredients, (i) intrinsic line profiles, or line broadening - ”atomic physics” part, and (ii) the radiative transfer problem - ”astrophysics” part. There is not enough space to discuss here the current status of the astrophysical part of the problem. Fortunately, this topic is covered by many reviews. There are two major problems here, (a) departures from local thermodynamic equilibrium (LTE) - the so-called non-LTE description (e.g. Mihalas 1978; Hubenyet al.1994); and (b) departures from complete frequency redistribution (Cooperet al.1989; Hubeny and Lites 1994).

An experimental study of argon condensation in cryogenic shock tubes

1983 ◽  
Vol 14 (6) ◽  
pp. 755-763 ◽  
Author(s):  
M.W. Matthew ◽  
J. Steinwandel
Keyword(s):  
Experimental Study ◽  
Shock Tubes

scholarly journals The Surface Gravities of Be Stars

1976 ◽  
Vol 70 ◽  
pp. 69-78 ◽  
Author(s):  
Geraldine J. Peters
Keyword(s):  
Main Sequence ◽  
Be Stars ◽  
Line Broadening ◽  
Hydrogen Line ◽  
Wide Range ◽  
Hα Emission ◽  
The Mean ◽  
Emission Strength

In an attempt to shed some light on the origin of the material in the envelopes of Be stars, surface gravities were determined for 30 objects by comparing their observed profiles of Hγ and Hδ with those computed from the Princeton model atmospheres and the VCS theory of hydrogen line broadening. The program stars are predominately well-known Be stars and display a wide range of envelope spectra and v sin i. The mean and range in log g for the Be stars appear to be identical to that obtained from a similar analysis on non-Be stars. No correlation was found between log g and Hα emission strength or the strength and/or presence of emission of Fe II, O I λ 7774 Å, or the infrared Ca ii triplet. The suggestion made by Schild (1973) and Schild et al. (1974) that the extreme Be stars are in the post main sequence phase of rapid core contraction is weakened by the fact that there are several members of the class which have log g ≥ 3.8. All shell stars considered in the program appear to have low values of log g (≤3.5). Some possible explanations for this occurrence are discussed.

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