scholarly journals X-Ray Spectra of Tokamak Plasma

1977 ◽  
Vol 43 ◽  
pp. 36-36
Author(s):  
B.S. Fraenkel
Keyword(s):  
Dielectronic Recombination ◽  
Tokamak Plasma ◽  
Doppler Width ◽  
X Ray ◽  
A Value

A spectrum covering Fe XXV to Fe XXII x ray lines from a tokamak (PLT) plasma has been obtained. Results indicate similarity with the flare spectrum in this region - the forbidden lines also appear in the PLT spectrum.Te was about 1.8 keV- a value confirmed by intensity of dielectronic recombination lines. Ti was found to be not more than 0.7 keV, by Doppler width of the He like singlet 1s2 –ls2p 1S0 -1P0. A Johansson crystal was used, with the spectrograph adapted for an extended X-ray source.

scholarly journals Supra Thermal Electron Tails Effects on X-Ray Line Emission in a Tokamak Plasma

1984 ◽  
Vol 86 ◽  
pp. 45-48 ◽  
Author(s):  
R. Bartiromo ◽  
F. Bombarda ◽  
R. Giannella
Keyword(s):  
Hydrogen Isotope ◽  
Line Emission ◽  
Dielectronic Recombination ◽  
Tokamak Plasma ◽  
Spectral Features ◽  
Thermal Electron ◽  
X Ray

The soft X-ray lines emitted by highly ionized impurities are one of the most prominent spectral features of today’s tokamaks. In fact the hydrogen isotope plasmas produced in these devices attain temperature values ranging from about one to several keV. A great deal of information about the plasma conditions can be drawn, in particular, from the highly resolved spectra of medium-Z ions which are very rich in satellites excited via dielectronic recombination and innner shell excitation (Dubau and Volontè 1980, Bitter et al. 1979).

scholarly journals New Calculations of Inner Shell X-Ray Lines in Ti, Cr, and Ni as Density Diagnostics

1984 ◽  
Vol 86 ◽  
pp. 50-50
Author(s):  
J.R. Lemen ◽  
K.J.H. Phillips ◽  
G.A. Doschek ◽  
R.D. Cowan
Keyword(s):  
Fine Structure ◽  
Density Dependence ◽  
Strong Dependence ◽  
Dielectronic Recombination ◽  
Ionization Rate ◽  
Rate Coefficients ◽  
Tokamak Plasma ◽  
Recombination Rates ◽  
X Ray ◽  
Density Dependent

We present new calculations for ls−2p transitions in C−, N−, and O-like Ti, Cr, and Ni for application to tokamak X-ray spectra. This extends our earlier work for the corresponding iron ions (Phillips et al. 1983, Ap.J. 265, 1120) in which a density dependence of line intensities was pointed out. These lines are principally formed by dielectronic recombination; the density effect arises due to the density-dependent populations of the fine structure levels in the ground configuration of the recombining ion. In the present work the calculations of the Ti, Cr, and Ni lines have been made for the wavelengths and the dielectronic recombination rates using a Hartree-Fock technique with statistical exchange. The density dependence of the collisionally excited transitions was also included. Density-dependent populations of the fine structure levels of the ground configuration were obtained from Feldman et al. (1980 J. Appl. Phys. 51, 190) and Bhatia et al. (1980, J. Appl. Phys. 51, 1464). In calculating the ionization fractions we have assumed coronal equilibrium; new ionization rate coefficients were calculated using the formalism given by Burgess and Chidichimo (1983). The spectra were synthesized with Voigt line profiles and typical tokamak radius-dependent temperature and density profiles were assumed. The N-like lines, in-particular show a strong dependence over tha range: <1011 −3.1013 cm−3 (Ti XVI) <1011 −3.1014 cm−3 (Cr XVIII), 1012 −1015 cm−3 (Ni XXII). If a density profile across the torus is available from Thomson-scattered laser radiation, observations of these lines may serve to show where the N-like ions are formed in the tokamak plasma.

scholarly journals Characterization of Chromium Compensated GaAs Sensors with the Charge-Integrating JUNGFRAU Readout Chip by Means of a Highly Collimated Pencil Beam

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1550
Author(s):  
Dominic Greiffenberg ◽  
Marie Andrä ◽  
Rebecca Barten ◽  
Anna Bergamaschi ◽  
Martin Brückner ◽  
...  
Keyword(s):  
Low Noise ◽  
State University ◽  
Noise Performance ◽  
X Ray ◽  
A Value ◽  
Resolution Capability ◽  
Sensor Properties ◽  
Pixel Pitch ◽  
Lower Noise

Chromium compensated GaAs or GaAs:Cr sensors provided by the Tomsk State University (Russia) were characterized using the low noise, charge integrating readout chip JUNGFRAU with a pixel pitch of 75 × 75 µm2 regarding its application as an X-ray detector at synchrotrons sources or FELs. Sensor properties such as dark current, resistivity, noise performance, spectral resolution capability and charge transport properties were measured and compared with results from a previous batch of GaAs:Cr sensors which were produced from wafers obtained from a different supplier. The properties of the sample from the later batch of sensors from 2017 show a resistivity of 1.69 × 109 Ω/cm, which is 47% higher compared to the previous batch from 2016. Moreover, its noise performance is 14% lower with a value of (101.65 ± 0.04) e− ENC and the resolution of a monochromatic 60 keV photo peak is significantly improved by 38% to a FWHM of 4.3%. Likely, this is due to improvements in charge collection, lower noise, and more homogeneous effective pixel size. In a previous work, a hole lifetime of 1.4 ns for GaAs:Cr sensors was determined for the sensors of the 2016 sensor batch, explaining the so-called “crater effect” which describes the occurrence of negative signals in the pixels around a pixel with a photon hit due to the missing hole contribution to the overall signal causing an incomplete signal induction. In this publication, the “crater effect” is further elaborated by measuring GaAs:Cr sensors using the sensors from 2017. The hole lifetime of these sensors was 2.5 ns. A focused photon beam was used to illuminate well defined positions along the pixels in order to corroborate the findings from the previous work and to further characterize the consequences of the “crater effect” on the detector operation.

Characterizing the Thermomechanical Degradation of a Filled Elastomer by Morphology and X Ray Photoelectron Spectroscopy

2001 ◽  
Vol 702 ◽  
Author(s):  
Giovanni F Crosta ◽  
Art J Nelson ◽  
Marina C Camatini
Keyword(s):  
Photoelectron Spectroscopy ◽  
Intrinsic Property ◽  
Binding Energies ◽  
Structural Domain ◽  
X Ray ◽  
Vulcanized Rubber ◽  
A Value ◽  
Debris Particles ◽  
Morphological Descriptor ◽  
Microscopy Images

ABSTRACTThree types of debris particles, denoted by L2, H2 and K3 respectively, originated from the abrasion of silica-filled, vulcanized rubber under different test conditions (severity) were analyzed and compared. The structural fractal dimension, DFS, of the particle perimeter was chosen as a morphological descriptor (but not necessarily as an intrinsic property of the fractured material !). Said dimension was estimated by processing light microscopy images. A value of the morphological threshold, TST, which separates the textural from the structural domain in the RICHARDSON plot was determined in order to maximize discrimination between the three particle types and rank them by increasing values of DFS. Particles from the highest severity test (K3) exhibited the highest value of DFS. X ray photoelectron spectroscopy (XPS) provided elemental composition, core level binding energies and the speciation of C, N, O, Si and S. As a result, L2 debris was found to originate from two processes: fracture of rubber and segregation of extender oil. Evidence has come both from morphology and XPS. Particles of H2 and K3 were ascribed to fracture alone. Comparison between K3 and the reference material, rasped rubber (RAS), shows the following: a) increase of the [S]/[C] surface atomic concentration ratio from RAS to K3; b) existence of multiple bonding states of S in K3 with energy peaking at 162.9 ± 0.3 eV ([-S-S-]n); c) weak contribution of R-S-O-R oxidized S species in K3 at 165 eV, not seen in RAS; d) no evidence of either SO3 or SO4 groups in any material. Although preliminary, these results prove the ability of morphological analysis and XPS to characterize the surface properties of debris particles non destructively.

Reactions of (η5-C9H7)Rh(η2-C2H4)2 with quinones: molecular structure of [(η5-C9H7)Rh(2,3,5,6-C6O2(CH3)4)]

1999 ◽  
Vol 77 (2) ◽  
pp. 199-204
Author(s):  
Stephen A Westcott ◽  
Nicholas J Taylor ◽  
Todd B Marder
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Ground State ◽  
Slip Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Hinge Angle

Reactions of (η5-C9H7)Rh(η2-C2H4)2 (1) with quinones were investigated. Substitution of the labile ethylene ligands was observed upon addition of either duroquinone (2,3,5,6-tetramethyl-1,4-benzoquinone) or 1,4-benzoquinone to complex 1. The molecular structure of neutral (η5-C9H7)Rh(2,3,5,6-C6O2(CH3)4) (3), determined by X-ray diffraction, shows that the duroquinone ligand lies in a plane nearly parallel to the indenyl group. The carbonyl moieties of duroquinone lie in a plane incorporating Rh, C2, and the midpoint between C3a and C7a of the indenyl ring. The slip parameter (Δ= d(average Rh-C3a,7a) -d(average Rh-C1,3)) was calculated to be 0.112(2) Å; whereas a value of ca. 0.05 Å had been obtained previously from film data. Values for the hinge angle (HA = angle between normals to the least-squares planes defined by C1, C2, C3 and C1, C7a, C3a, C3) and fold angle (FA = angle between normals to the least-squares planes defined by C1, C2, C3 and C3a, C4, C5, C7, C7a) are 7.2° and 4.0°, respectively.Key words: indenyl, rhodium, quinones, ring-slippage, ground-state distortion.

Optimization of GEM-based detector readout electrode structure for SXR imaging of tokamak plasma

2021 ◽  
Vol 16 (11) ◽  
pp. C11014
Author(s):  
K. Malinowski ◽  
M. Chernyshova ◽  
S. Jabłoński ◽  
I. Casiragi
Keyword(s):  
Energy Range ◽  
Tokamak Plasma ◽  
Detective Quantum Efficiency ◽  
Actual Number ◽  
Electrode Structure ◽  
X Ray ◽  
X Ray Imaging ◽  
Input Spectrum ◽  
Electron Avalanches ◽  
Time Coincidence

Abstract The paper presents an optimization of a readout structure of the GEM-based detector designed for X-ray imaging for DTT tokamak in the energy range of 2–15 keV. The readout electrode of approximately 100 cm2 surface is composed of hexagonal pixels connected in a way that allows reducing the actual number of signal pixels (electronics channels). At the same time, based on time coincidence analysis, it makes possible to unambiguously identify the position of the recorded X-ray photon. For the input spectrum, the Detective Quantum Efficiency (DQE) of the detector was calculated using the Geant4 program and the spatial distributions of electron avalanches at the readout electrode were simulated using the Garfield++ program. These were conducted for a given energy range of radiation and a statistical distribution consistent with the shape of the spectrum considering the DQE of the detector. As a result, the size of a single hexagonal pixel was proposed to capture the position of the recorded radiation quanta in an optimal and effective way.

scholarly journals Elaboration of nitride thin films by reactive sputtering

2006 ◽  
Vol 59 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Pierre Yves Jouan ◽  
Arnaud Tricoteaux ◽  
Nicolas Horny
Keyword(s):  
Thin Films ◽  
Compressive Stress ◽  
Bias Voltage ◽  
Substrate Surface ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Dc Reactive Magnetron Sputtering ◽  
Nitrogen Contents

The aim of this paper is first a better understanding of DC reactive magnetron sputtering and its implications, such as the hysteresis effect and the process instability. In a second part, this article is devoted to an example of specific application: Aluminium Nitride. AlN thin films have been deposited by reactive triode sputtering. We have studied the effect of the nitrogen contents in the discharge and the RF bias voltage on the growth of AlN films on Si(100) deposited by triode sputtering. Stoichiometry and crystal orientation of AlN films have been characterized by means of Fourier-transform infrared spectroscopy, X-ray diffraction and secondary electron microscopy. Dense and transparent AlN layers were obtained at high deposition rates. These films have a (002) orientation whatever the nitrogen content in the discharge, but the best crystallised ones are obtained at low value (10%). A linear relationship was observed between the AlN lattice parameter "c" (perpendicular to the substrate surface) and the in-plane compressive stress. Applying an RF bias to the substrate leads to a (100) texture, and films become amorphous. Moreover, the film's compressive stress increases up to a value of 8GPa before decreasing slowly as the bias voltage increases.

scholarly journals Analysis of grape fruits and grape seed for their major , minor and trace elemental contact by XRF technique

2011 ◽  
Vol 8 (2) ◽  
pp. 618-624
Author(s):  
Baghdad Science Journal
Keyword(s):  
Radiation Source ◽  
Grape Seed ◽  
Medical Studies ◽  
Grape Seeds ◽  
Experimental Conditions ◽  
Experimental Procedure ◽  
X Ray ◽  
Minor Elements ◽  
A Value ◽  
Trace Elemental

Grapes and grape seeds are important samples employed for environmental medical studies . The air of this work was to identify and concentration calculation of the elements in grapes fruit and thier seeds by using X-Ray fluoresces technique (XRF) . Samples were collected from Abo Ghraib of Baghdad city ,the grape seeds were obtained from those samples . Both samples were taken under experimental procedure to obtain the sample which were ready for analysis . The samples were then submitted to experimental conditions using a radiation source and then samples were applied for counting analysis shows the elements Na , Mg , Al , Si , P , S , Cl , K , Ca , and Sr as major components of the samples. Fe , Sr , I , Ba and V were found an minor elements other elements Cr , Cu , Sn , Sb , Te gave a value of 5 – 10 ppm , Co , Ni , Rb , Ag ,Cd < 5 ppm for the samples of grape seeds . The analysis of grape seeds present Sr , Ca , K , Cl , S , Si , P as major components of the samples, and gave a values for Cr and Rb , Sn , Sb and Te (5 – 10 ppm) , while Co , Rb , Ni , Ag ,Cd (Less than 5 ppm) .

scholarly journals Study of composition and structure of NLMK BF No. 6 hearth scull (Report 1)

2019 ◽  
Vol 75 (2) ◽  
pp. 166-181
Author(s):  
I. F. Кurunov ◽  
A. S. Bliznyukov ◽  
V. N. Titov ◽  
N. V. Logvinov ◽  
D. N. Tikhonov ◽  
...  
Keyword(s):  
Visual Inspection ◽  
Iron Carbide ◽  
Iron Notch ◽  
X Ray ◽  
A Value ◽  
Composition And Structure ◽  
Variable Content ◽  
Technical Solutions ◽  
Titanium Compounds ◽  
Bottom Lining

Analysis of blast furnaces running experience in Japan, Europe and North America shows, that duration of their operating period determines to a great extent by hearth and bottom lining endurance. Study of structure change of scull and hearth walls and bottom lining at different burden compositions and BF heat conditions will enable to elaborate organization and technical solutions for BF efficiency increasing. Study of hearth scull composition at the level of iron notch and lower at PAO NLMK BF No. 6 after 2nd category overhaul stoppage from 26.08.2016 through 29.09.2016. Lump samples of mass from 10 up to 70 kg were taken with careful visual inspection to exclude oxidized and hydrated pieces. Based on visual inspection of samples as well as petrographic, chemical, X-ray structural and microprobe analysis it was determined, that the scull base comprises products formed during crystallization of heat products. They included a metal, in which a magnetic part (α-iron) is prevailed with iron carbide and graphite inclusions, graphite as a separate phase, slag components with a base of melilite at the level of iron notch and silicates (X-ray amorphous) of variable content of СaO–K2O–Na2O–SiO2–Al2O3system. The quantity of metal and graphite in the hearth walls scull increases from iron notch to the bottom and reaches a value >85 % at the level 300 mm lower than iron notch. Content of titanium compounds in oxide form in all the samples as well as nitrides, carbo-nitrides totally does not exceeds 1–2%. 

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