scholarly journals Probing Electron Properties in ECR Plasmas Using X-ray Bremsstrahlung and Fluorescence Emission

2021 ◽  
Vol 6 (4) ◽  
pp. 41
Author(s):  
Bharat Mishra ◽  
Angelo Pidatella ◽  
Alessio Galatà ◽  
Sandor Biri ◽  
Richard Rácz ◽  
...  
Keyword(s):  
Electron Cyclotron Resonance ◽  
Fluorescence Emission ◽  
Argon Plasma ◽  
Valuable Insight ◽  
X Ray ◽  
Ecr Plasma ◽  
Spatial Properties ◽  
Spectrally Resolved ◽  
Insight Into ◽  
Structural Aspects

A quantitative analysis of X-ray emission from an electron cyclotron resonance (ECR) plasma was performed to probe the spatial properties of electrons having energy for effective ionisation. A series of measurements were taken by INFN-LNS and ATOMKI, capturing spatially and spectrally resolved X-ray maps as well as volumetric emissions from argon plasma. Comparing the former with model generated maps (involving space-resolved phenomenological electron energy distribution function and geometrical efficiency calculated using ray-tracing Monte Carlo (MC) routine) furnished information on structural aspects of the plasma. Similarly, fitting a model composed of bremsstrahlung and fluorescence to the volumetric X-ray spectrum provided valuable insight into the density and temperature of confined and lost electrons. The latter can be fed back to existing electron kinetics models for simulating more relevant energies, consequently improving theoretical X-ray maps and establishing the method as an excellent indirect diagnostic tool for warm electrons, required for both fundamental and applied research in ECR plasmas.

Preparation And Characterization Of Carbon Nitride Thin Films By Electron Cyclotron Resonance (Ecr) Sputtering Method

1998 ◽  
Vol 555 ◽  
Author(s):  
Yoshifumi Aoi ◽  
Youji Tani ◽  
Masaaki Hisa ◽  
Eiji Kamijo
Keyword(s):  
Substrate Temperature ◽  
Photoelectron Spectroscopy ◽  
Cyclotron Resonance ◽  
Carbon Nitride ◽  
Electron Cyclotron Resonance ◽  
Electron Cyclotron ◽  
X Ray ◽  
Ecr Plasma ◽  
Plasma Sputtering ◽  
Gas Atmosphere

AbstractCrystalline carbon nitride films were deposited by electron cyclotron resonance (ECR) plasma sputtering method using a carbon target and a nitrogen gas atmosphere. The deposited films were characterized by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and X-ray diffraction (XRD). Nitrogen content of the deposited film was varied with substrate selfbias potential and substrate temperature. Bonding states of nitrogen and carbon in the deposited filns were different according to the substrate temperature, sp3 C-N bonds were observed for the film deposited at 600 °C. Crystallization of carbon nitride thin film was observed hen the deposition was carried out an elevated substrate temperature.

Surface precipitates on single crystal LiNbO3 after dry-etching by CHF3 plasma

1998 ◽  
Vol 13 (3) ◽  
pp. 527-529 ◽  
Author(s):  
Kaori Shima ◽  
Naoki Mitsugi ◽  
Hirotoshi Nagata
Keyword(s):  
Photoelectron Spectroscopy ◽  
Cyclotron Resonance ◽  
Auger Electron ◽  
Electron Cyclotron Resonance ◽  
Machining Process ◽  
Optical Modulators ◽  
X Ray ◽  
Ecr Plasma ◽  
Etched Surface ◽  
Dry Etch

The CHF3 electron cyclotron resonance (ECR) plasma etched LiNbO3 (LN) surface was analyzed chemically and crystallographically to investigate the dry-etch machining process for LN crystal, which was recently needed to obtain broader-band optical modulators. The etched surface was entirely covered with amorphous-like precipitates having ~70 nm diameter. These precipitates (or a part of them) were thought to be LiF from Auger electron and x-ray photoelectron spectroscopy. The results indicated that the LiF was formed and remained on the etched surface while the Nb was almost completely removed.

AlN Grown by Metalorganic Molecular Beam Epitaxy

1994 ◽  
Vol 363 ◽  
Author(s):  
J. D. Mackenzie ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
R. G. Wilson
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Electron Cyclotron Resonance ◽  
Nitrogen Sources ◽  
Plasma Source ◽  
Structural Quality ◽  
X Ray ◽  
Ecr Plasma ◽  
Metalorganic Molecular Beam Epitaxy ◽  
Surface Morphologies

AbstractThin film AlN has been grown on Al2O3 and GaAs substrates by metalorganic molecular beam epitaxy (MOMBE) using amine bonded alane precursors, tertiarybutylamine, and nitrogen from a compact electron cyclotron resonance (ECR) plasma source operating at 2.45 GHz. Typical growth pressures were in the 0.5 − 1 × 10−4 Torr range. The growth rates, impurity backgrounds and surface morphologies were examined for both nitrogen sources and both the solid and liquid alanes. In general, growth efficiencies were good for both alane precursors, allowing for deposition of the low temperature, ∼ 400°C, AlN buffers needed for subsequent growth of GaN and InGaAlN alloys. Low growth temperatures could not be obtained using tertiarybutylamine, presumably due to poor decomposition efficiency of the source at low temperatures. The structural quality of material grown at high temperatures from the ECR plasma was measured by atomic force microscopy (AFM) and high resolution x-ray diffraction (HRXRD), indicating a surface roughness of ∼ 8 Å and an x-ray width half maximum (FWHM) of 430 arcsec.

scholarly journals A multi-wavelength view of NGC 1624-2

2016 ◽  
Vol 12 (S329) ◽  
pp. 394-394
Author(s):  
A. David-Uraz ◽  
V. Petit ◽  
R. MacInnis ◽  
C. Erba ◽  
S. P. Owocki ◽  
...  
Keyword(s):  
Massive Star ◽  
Velocity Structure ◽  
Massive Stars ◽  
Valuable Insight ◽  
Complex Field ◽  
Stellar Objects ◽  
X Ray ◽  
Multi Wavelength ◽  
Consistent Picture ◽  
Insight Into

AbstractLarge magnetometric surveys have contributed to the detection of an increasing number of magnetic massive stars, and to the recognition of a population of magnetic massive stellar objects with distinct properties. Among these, NGC 1624-2 possesses the largest magnetic field of any O-type star; such a field confines the stellar wind into a circumstellar magnetosphere, which can be probed using observations at different wavelength regimes. Recent optical and X-ray observations suggest that NGC 1624-2’s magnetosphere is much larger than that of any other magnetic O star. By modeling the variations of UV resonance lines, we can constrain its velocity structure. Furthermore, recent spectropolarimetric observations raise the possibility of a more complex field topology than previously expected. Putting all of these multi-wavelength constraints together will allow us to paint a consistent picture of NGC 1624-2 and its surprising behavior, giving us valuable insight into the very nature of massive star magnetospheres.

Understanding strength and texture in Fe at planetary core pressures and temperatures: insights from laser compression experiments

2020 ◽  
Author(s):  
Sébastien Merkel ◽  
Sovanndara Hok ◽  
Cynthia Bolme ◽  
Arianna Gleason ◽  
Wendy Mao
Keyword(s):  
Extreme Conditions ◽  
Valuable Insight ◽  
Extreme Pressure ◽  
X Ray Diffraction ◽  
High Pressure And Temperature ◽  
X Ray ◽  
The Earth ◽  
Linac Coherent Light Source ◽  
Insight Into

<p>Determining the high pressure and temperature behavior of iron (Fe) provides valuable insight into the evolution and dynamics of the Earth’s core. Shock compression using lasers can achieve extreme pressure and temperature conditions simultaneously. The duration of the extreme conditions state is on the order of nanoseconds. This is a challenge for in situ measurements of the shocked material’s properties. In this work, we shock-compressed polycrystalline iron at the Matter in Extreme Conditions End Station at the Linac Coherent Light Source, SLAC National Accelerator Laboratory and performed in situ X-ray diffraction (XRD) measurements with sub-picosecond time resolution. The final aim of these experiments is the study of stress of texure in Fe under extreme conditions of pressure and temperature. The presentation will highlight the strategies for such experiment and data processing and present our premilinary results.</p>

Study of the resistor material of an automotive spark plug by use of the charge-up effect along with elemental mapping in an electron microprobe

1991 ◽  
Vol 49 ◽  
pp. 742-743
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
J. S. Park ◽  
B. N. Juterbock
Keyword(s):  
Electron Microprobe ◽  
Present Report ◽  
Coated Sample ◽  
Valuable Insight ◽  
Elemental Mapping ◽  
Spark Plug ◽  
Carbon Coated ◽  
Electron Image ◽  
Electron Imaging ◽  
Insight Into

The electric and thermal properties of the resistor material in an automotive spark plug should be stable during its service lifetime. Containing many elements and many phases, this material has a very complex microstructure. Elemental mapping with an electron microprobe can reveal the distribution of all relevant elements throughout the sample. In this work, it is demonstrated that the charge-up effect, which would distort an electron image and, therefore, is normally to be avoided in an electron imaging work, could be used to advantage to reveal conductive and resistive zones in a sample. Its combination with elemental mapping can provide valuable insight into the underlying conductivity mechanism of the resistor.This work was performed in a CAMECA SX-50 microprobe. The spark plug used in the present report was a commercial product taken from the shelf. It was sectioned to expose the cross section of the resistor. The resistor was known not to contain the precious metal Au as checked on the carbon coated sample. The sample was then stripped of carbon coating and re-coated with Au.

Quantitative Analysis Of X-Ray Images From Geological Materials

1990 ◽  
Vol 48 (2) ◽  
pp. 244-245
Author(s):  
J. M. Paque ◽  
R. Browning ◽  
P. L. King ◽  
P. Pianetta
Keyword(s):  
Quantitative Analysis ◽  
Bulk Composition ◽  
Principal Component ◽  
Analytical Description ◽  
Bulk Sample ◽  
Geological Samples ◽  
X Ray ◽  
Software And Hardware ◽  
And Storage ◽  
Insight Into

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.

Argon Plasma Induced Surface Modifications For Resistless Patterning Of Aluminium Films

1991 ◽  
Vol 223 ◽  
Author(s):  
Neeta Agrawal ◽  
R. D. Tarey ◽  
K. L. Chopra
Keyword(s):  
Etch Rate ◽  
Argon Plasma ◽  
Surface Modifications ◽  
Surface Chemical ◽  
Plasma Exposure ◽  
X Ray ◽  
Aluminium Fluoride ◽  
A New Technique ◽  
Plasma Exposure Time ◽  
Surface Chemical Modification

ABSTRACTArgon plasma exposure has been used to induce surface chemical modification of aluminium thin films, causing a drastic change in etch rate in standard HNO3/CH3COOH/H3PO4 etchant. The inhibition period was found to increase with power and Ar plasma exposure time. Auger electron and x-ray photoelectron spectroscopies have indicated formation of an aluminium fluoride (AlF3) surface layer due to fluorine contamination originating from the residue left in the plasma chamber during CF4 processing. The high etch selectivity between unexposed and argon plasma exposed regions has been exploited as a new technique for resistless patterning of aluminium.

Quantum Mechanical Interpretation of the Ultra-Low Energy Methyl-Rotation Dynamics in Porous Metal-Organic Frameworks Probed by Low-Frequency Vibrational Spectroscopy and ab initio Simulations

2018 ◽  
Author(s):  
Qi Li ◽  
Adam J. Zaczek ◽  
Timothy M. Korter ◽  
J. Axel Zeitler ◽  
Michael T. Ruggiero
Keyword(s):  
Ab Initio ◽  
Metal Organic Frameworks ◽  
Low Frequency ◽  
Rotor Dynamics ◽  
Quantum Mechanical ◽  
Valuable Insight ◽  
Void Space ◽  
Ab Initio Simulations ◽  
Metal Organic ◽  
Insight Into

<div>Understanding the nature of the interatomic interactions present within the pores of metal-organic frameworks</div><div>is critical in order to design and utilize advanced materials</div><div>with desirable applications. In ZIF-8 and its cobalt analogue</div><div>ZIF-67, the imidazolate methyl-groups, which point directly</div><div>into the void space, have been shown to freely rotate - even</div><div>down to cryogenic temperatures. Using a combination of ex-</div><div>perimental terahertz time-domain spectroscopy, low-frequency</div><div>Raman spectroscopy, and state-of-the-art ab initio simulations,</div><div>the methyl-rotor dynamics in ZIF-8 and ZIF-67 are fully charac-</div><div>terized within the context of a quantum-mechanical hindered-</div><div>rotor model. The results lend insight into the fundamental</div><div>origins of the experimentally observed methyl-rotor dynamics,</div><div>and provide valuable insight into the nature of the weak inter-</div><div>actions present within this important class of materials.</div>

Copper–oxygen Dynamics in Tyrosinase

2019 ◽  
Author(s):  
Nobutaka Fujieda ◽  
Sachiko Yanagisawa ◽  
Minoru Kubo ◽  
Genji Kurisu ◽  
Shinobu Itoh
Keyword(s):  
Catalytic Mechanism ◽  
Substrate Binding ◽  
Active Form ◽  
Copper Ion ◽  
Atomic Resolution ◽  
Oxygen Species ◽  
X Ray ◽  
Oxygen Dynamics ◽  
Insight Into ◽  
Copper Centre

To unveil the activation of dioxygen on the copper centre (Cu<sub>2</sub>O<sub>2</sub>core) of tyrosinase, we performed X-ray crystallograpy with active-form tyrosinase at near atomic resolution. This study provided a novel insight into the catalytic mechanism of the tyrosinase, including the rearrangement of copper-oxygen species as well as the intramolecular migration of copper ion induced by substrate-binding.<br>

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