scholarly journals Highly Stripped Ions (Up to Mo XXXIII) and Forbidden Mo Lines in the Soft X-Ray Spectrum from TFR Tokamak

1977 ◽  
Vol 43 ◽  
pp. 37-37
Author(s):  
M. Klapisch ◽  
M. Finkenthal ◽  
B.S. Fraenkel ◽  
N. Schweitzer ◽  
J. L. Schwob

The spectrum of the TFR Tokamak has been observed in the range 5-100 Å. Identification of Mo XIV to Mo XXXIII lines originating from the limiter was achieved by comparison with the Mo spectrum emitted from a low-inductance vacuum spark, and with relativistic calculations. Some of the TFR lines were identified as forbidden transitions (electric quadrupole). The appearance of these lines depending on plasma parameters is discussed.

1973 ◽  
Vol 28 (10) ◽  
pp. 1635-1641 ◽  
Author(s):  
A. G. de Pinho ◽  
M. Weksler

The X-ray spectra resulting from the internal conversion of electric quadrupole transitions following the alpha decay of Th230 and Ra226 were analysed with a Si (Li) spectrometer. From the knowledge of the Coster-Kronig and fluorescence yields, the internal conversion coefficients of the E2 transitions from the first excited states in Ra226 and Rn222 could be deduced. Results are in good agreement with theoretical values.


2011 ◽  
Vol 37 (11) ◽  
pp. 935-947 ◽  
Author(s):  
E. O. Baronova ◽  
V. P. Vinogradov ◽  
V. I. Krauz ◽  
V. V. Myalton ◽  
A. M. Stepanenko ◽  
...  
Keyword(s):  

2012 ◽  
Vol 21 (4) ◽  
Author(s):  
D. A. Bezrukov ◽  
B. I. Ryabov ◽  
K. Shibasaki

AbstractOn the base of the 17 GHz radio maps of the Sun taken with the Nobeyama Radio Heliograph we estimate plasma parameters in the specific region of the sunspot atmosphere in the active region AR 11312. This region of the sunspot atmosphere is characterized by the depletion in coronal emission (soft X-ray and EUV lines) and the reduced absorption in the a chromospheric line (He I 1.083 μm). In the ordinary normal mode of 17 GHz emission the corresponding dark patch has the largest visibility near the central solar meridian. We infer that the reduced coronal plasma density of about ~ 5 × 10


1991 ◽  
Vol 9 (2) ◽  
pp. 501-515 ◽  
Author(s):  
P. Glas ◽  
M. Schnürer

We investigated the case where two laser-produced plasmas collide nearly head on. Special attention was devoted to the fundamentals necessary to realize a coherent X-ray source. A gas-dynamic computational analysis was performed to understand the evolution of the density, the temperature, and the velocity of merging plasmas. The spatial intensity distribution of selected spectral lines reveals that the interaction of plasmas of different nuclear charge and charge state is not strictly collision dominated. Using spectral line intensity ratios, we determined electron temperatures and electron number densities, as well as the intensity inversion on the 4–1 to 3–1 resonance transitions of [He]-like Al. Inversion occurs in the vicinity of the targets if identical materials are used (Al–Al) and is possibly indicated in the interaction zone for different ones (Al–Cu), too. The inversion factors (and the gain coefficient) for the 4–3 transition of [He]-like Al at about 130 Å were estimated.


The spatial distribution of the emission in several X-ray lines is discussed with emphasis on temperature dependence and association with active regions. New results are presented for the trio of helium-like O vii lines which demonstrate (1) a spatial variation in the density dependent forbidden to intersystem line ratio, and (2) a strong spatial variation in the intensity of the O vii resonance line relative to the optically forbidden transitions. The second effect appears to be caused by resonance scattering by material in the line of sight.


2019 ◽  
Vol 37 (03) ◽  
pp. 276-287
Author(s):  
K. A. Schultz ◽  
V. L. Kantsyrev ◽  
A. S. Safronova ◽  
V. V. Shlyaptseva ◽  
E. E. Petkov ◽  
...  

AbstractWe present a broad study of linear, clustered, noble gas puffs irradiated with the frequency doubled (527 nm) Titan laser at Lawrence Livermore National Laboratory. Pure Ar, Kr, and Xe clustered gas puffs, as well as two mixed-gas puffs consisting of KrAr and XeKrAr gases, make up the targets. Characterization experiments to determine gas-puff density show that varying the experimental parameter gas-delay timing (the delay between gas puff initialization and laser-gas-puff interaction) provides a simple control over the gas-puff density. X-ray emission (>1.4 keV) is studied as a function of gas composition, density, and delay timing. Xe gas puffs produce the strongest peak radiation in the several keV spectral region. The emitted radiation was found to be anisotropic, with smaller X-ray flux observed in the direction perpendicular to both laser beam propagation and polarization directions. The degree of anisotropy is independent of gas target type but increases with photon energy. X-ray spectroscopic measurements estimate plasma parameters and highlight their difference with previous studies. Electron beams with energy in excess of 72 keV are present in the noble gas-puff plasmas and results indicate that Ar plays a key role in their production. A drastic increase in harder X-ray emissions (X-ray flash effect) and multi-MeV electron-beam generation from Xe gas-puff plasma occurred when the laser beam was focused on the front edge of the linear gas puff.


1972 ◽  
Vol 14 ◽  
pp. 589-591 ◽  
Author(s):  
J. L. Schwob ◽  
B. S. Fraenkel

X-ray radiation is obtained from a point plasma produced by pinch effect Cohen et al. (1968) in a vacuum spark similar to that used by Lie and Elton (1971) with a 220 kA peak current. The extremely dense and hot minute plasma appears at a distance of 0.5 to 1 mm from the anode tip and has maximum dimensions of a few microns.The spectroscopic observations are performed by means of a focusing Cauchois spectrometer so as to avoid effects of fluctuations in the source position.


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