Ion energy distribution and non-linear ion dynamics in BP-HiPIMS and ACBP-HiPIMS discharge

2022 ◽  
Author(s):  
Han Mingyue ◽  
Yang Luo ◽  
Liuhe Li ◽  
Hua Li ◽  
Ye Xu ◽  
...  
Keyword(s):  
Layer Structure ◽  
High Energy ◽  
Industrial Applications ◽  
Distribution Functions ◽  
Field Energy ◽  
Floating Potential ◽  
Ion Dynamics ◽  
Ion Energy ◽  
Positive Pulse ◽  
The Mean

Abstract Investigating the ion dynamics in the emerging bipolar pulse high power impulse magnetron sputtering (BP-HiPIMS) discharge is necessary and important for broadening its industrial applications. Recently, an optimized plasma source operating the BP-HiPIMS with an auxiliary anode and a solenoidal coil is proposed to enhance the plasma flux and energy, named as ACBP-HiPIMS (‘A’－anode, ‘C’－coil). In the present work, the temporal evolutions of the ion velocity distribution functions (IVDF) in BP-HiPIMS and ACBP-HiPIMS discharges are measured using a retarding field energy analyser (RFEA). For the BP-HiPIMS discharge, operated at various positive pulse voltages U+, the temporal evolutions of IVDFs illustrate that there are two high-energy peaks, E1 and E2, which are both lower than the applied U+. The ratio of the mean ion energy Ei,mean to the applied U+ is around 0.55－0.6 at various U+. In ACBP-HiPIMS discharge, the IVDF evolution shows three distinguishable stages which has the similar evolution trend with the floating potential Vf on the RFEA frontplate: (i) the stable stage with two high-energy peaks (E2 and E3 with energy respectively lower and higher than the applied U+ amplitude) when the floating potential Vf is close to the applied positive pulse voltage; (ii) the transition stage with low-energy populations when the Vf drops by ~20 V within ~10 μs; and (iii) the oscillation stage with alternating E2 and E3 populations and ever-present E1 population when the Vf slighly descreases unitl to the end of positive pulse. The comparison of IVDFs in BP-HiPIMS and ACBP-HiPIMS suggests that both the mean ion energy and high-energy ion flux have been effectively improved in ACBP-HiPIMS discharge. The formation of floating potential drop is explored using the Langmuir probe which may be attributed to the establishment of anode double layer structure.

Anisotropy of damage productions in electron irradiated molybdenum

1978 ◽  
Vol 36 (1) ◽  
pp. 354-355
Author(s):  
K. Izui ◽  
S. Furuno ◽  
H. Otsu ◽  
T. Nishida ◽  
H. Maeta
Keyword(s):  
Electron Flux ◽  
Threshold Energy ◽  
High Energy ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
Displacement Threshold ◽  
The Mean ◽  
Channeling Effect ◽  
Different Origins ◽  
Threshold Energies

Anisotropy of damage productions in crystals due to high energy electron bombardment are caused from two different origins. One is an anisotropic displacement threshold energy, and the other is an anisotropic distribution of electron flux near the atomic rows in crystals due to the electron channeling effect. By the n-beam dynamical calculations for germanium and molybdenum we have shown that electron flux at the atomic positions are from ∽4 to ∽7 times larger than the mean incident flux for the principal zone axis directions of incident 1 MeV electron beams, and concluded that such a locally increased electron flux results in an enhanced damage production. The present paper reports the experimental evidence for the enhanced damage production due to the locally increased electron flux and also the results of measurements of the displacement threshold energies for the <100>,<110> and <111> directions in molybdenum crystals by using a high voltage electron microscope.

Study of pumping effect in flow-through electrolysers

1983 ◽  
Vol 48 (8) ◽  
pp. 2232-2248 ◽  
Author(s):  
Ivo Roušar ◽  
Michal Provazník ◽  
Pavel Stuhl
Keyword(s):  
Natural Convection ◽  
Balance Equation ◽  
Volume Fraction ◽  
Industrial Applications ◽  
Pumping Effect ◽  
Flow Through ◽  
The Mean ◽  
The Difference

In electrolysers with recirculation, where a gas is evolved, the pumping of electrolyte from a lower to a higher level can be effected by natural convection due to the difference between the densities of the inlet electrolyte and the gaseous emulsion at the outlet. An accurate balance equation for calculation of the rate of flow of the pumped liquid is derived. An equation for the calculation of the mean volume fraction of bubbles in the space between the electrodes is proposed and verified experimentally on a pilot electrolyser. Two examples of industrial applications are presented.

scholarly journals General dispersion properties of magnetized plasmas with drifting bi-Kappa distributions. DIS-K: Dispersion Solver for Kappa Plasmas

2021 ◽  
Vol 87 (3) ◽  
Author(s):  
R.A. López ◽  
S.M. Shaaban ◽  
M. Lazar
Keyword(s):  
Dominant Role ◽  
High Energy ◽  
Distribution Functions ◽  
Magnetized Plasma ◽  
Unstable Wave ◽  
Space Plasmas ◽  
Good Representation ◽  
Particle Interactions ◽  
Particle Collisions ◽  
Dispersion Tensor

Space plasmas are known to be out of (local) thermodynamic equilibrium, as observations show direct or indirect evidences of non-thermal velocity distributions of plasma particles. Prominent are the anisotropies relative to the magnetic field, anisotropic temperatures, field-aligned beams or drifting populations, but also, the suprathermal populations enhancing the high-energy tails of the observed distributions. Drifting bi-Kappa distribution functions can provide a good representation of these features and enable for a kinetic fundamental description of the dispersion and stability of these collision-poor plasmas, where particle–particle collisions are rare but wave–particle interactions appear to play a dominant role in the dynamics. In the present paper we derive the full set of components of the dispersion tensor for magnetized plasma populations modelled by drifting bi-Kappa distributions. A new solver called DIS-K (DIspersion Solver for Kappa plasmas) is proposed to solve numerically the dispersion relations of high complexity. The solver is validated by comparing with the damped and unstable wave solutions obtained with other codes, operating in the limits of drifting Maxwellian and non-drifting Kappa models. These new theoretical tools enable more realistic characterizations, both analytical and numerical, of wave fluctuations and instabilities in complex kinetic configurations measured in-situ in space plasmas.

scholarly journals The Surgical Outcomes of Unstable Ankle Fractures in Patients Aged >65 Years

2021 ◽  
Vol 12 ◽  
pp. 215145932199776
Author(s):  
Adem Sahin ◽  
Anıl Agar ◽  
Deniz Gulabi ◽  
Cemil Erturk
Keyword(s):  
Surgical Outcomes ◽  
External Rotation ◽  
High Energy ◽  
Ankle Fractures ◽  
Medial Malleolus ◽  
Aofas Score ◽  
Non Union ◽  
The Mean ◽  
Medial Malleolus Fracture ◽  
Mechanism Of Trauma

Aim: To evaluate the surgical outcomes and complications of patients over 65 years of age, with unstable ankle fractures. Material and Method: The study included 111 patients (73F/38 M) operated on between January 2015 and February 2019 and followed up for a mean of 21.2 months (range, 6-62 months).Demographic characteristics, comorbidities, fracture type, and mechanisms of injury were evaluated. Relationships between postoperative complications and comorbidities were examined. In the postoperative functional evaluations, the AOFAS score was used and pre and postoperative mobilization (eg, use of assistive devices) was assessed. Results: The mean age of the patients was 70.5 ± 6.1 years (range, 65-90 years). The mechanism of trauma was low-energy trauma in 90.1% of the fractures and high-energy trauma in 9.9%. The fractures were formed with a SER injury (supination external rotation) in 83.7% of cases and bimalleolar fractures were seen most frequently (85/111, 76%).Complications developed in 16 (14.4%) patients and a second operation was performed in 11 (9.9%) patients with complications. Plate was removed and debridement was performed in 5 of 6 patients due to wound problems. Nonunion was developed in the medial malleolus in 4 patients. Revision surgery was performed because of implant irritation in 2 patients and early fixation loss in the medial malleolus fracture in one patient. Calcaneotibial arthrodesis was performed in 3 patients because of implant failure and ankle luxation associated with non-union. A correlation was determined between ASA score and DM and complications, but not with osteoporosis. The mean follow-up AOFAS score was 86.7 ± 12.5 (range, 36-100).A total of 94 (84.7%) patients could walk without assistance postoperatively and 92 (82.9%) were able to regain the preoperative level of mobilization. Conclusion: Although surgery can be considered an appropriate treatment option for ankle fractures in patients aged >65 years, care must be taken to prevent potential complications and the necessary precautions must be taken against correctable comorbidities.

scholarly journals High-energy operator product expansion at sub-eikonal level

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Giovanni Antonio Chirilli
Keyword(s):  
Operator Product Expansion ◽  
Evolution Equations ◽  
Energy Operator ◽  
High Energy ◽  
Structure Functions ◽  
Distribution Functions ◽  
Impact Factors ◽  
Operator Product ◽  
The Impact ◽  
New Distribution

Abstract The high energy Operator Product Expansion for the product of two electromagnetic currents is extended to the sub-eikonal level in a rigorous way. I calculate the impact factors for polarized and unpolarized structure functions, define new distribution functions, and derive the evolution equations for unpolarized and polarized structure functions in the flavor singlet and non-singlet case.

scholarly journals Importance of a Follow-Up Ultrasound Protocol in Monitoring Posttraumatic Spleen Complications in Children Treated with a Non-Operative Management

Medicina ◽  
2021 ◽  
Vol 57 (8) ◽  
pp. 734
Author(s):  
Ivona Djordjevic ◽  
Dragoljub Zivanovic ◽  
Ivana Budic ◽  
Ana Kostic ◽  
Danijela Djeric
Keyword(s):  
Splenic Abscess ◽  
Operative Management ◽  
High Energy ◽  
Significant Difference ◽  
Injury Grade ◽  
Grade Ii ◽  
The Mean ◽  
Non Operative Management ◽  
Grade Iii

Background and objectives: For the last three decades, non-operative management (NOM) has been the standard in the treatment of clinically stable patients with blunt spleen injury, with a success rate of up to 95%. However, there are no prospective issues in the literature dealing with the incidence and type of splenic complications after NOM. Materials and methods: This study analyzed 76 pediatric patients, up to the age of 18, with blunt splenic injury who were treated non-operatively. All patients were included in a posttraumatic follow-up protocol with ultrasound examinations 4 and 12 weeks after injury. Results: The mean age of the children was 9.58 ± 3.97 years (range 1.98 to 17.75 years), with no statistically significant difference between the genders. The severity of the injury was determined according to the American Association for Surgery of Trauma (AAST) classification: 7 patients had grade I injuries (89.21%), 21 patients had grade II injuries (27.63%), 33 patients had grade III injuries (43.42%), and 15 patients had grade IV injuries (19.73%). The majority of the injuries were so-called high-energy ones, which were recorded in 45 patients (59.21%). According to a previously created posttraumatic follow-up protocol, complications were detected in 16 patients (21.05%). Hematomas had the highest incidence and were detected in 11 patients (14.47%), while pseudocysts were detected in 3 (3.94%), and a splenic abscess and pseudoaneurysm were detected in 1 patient (1.31%), respectively. The complications were in a direct correlation with injury grade: seven occurred in patients with grade IV injuries (9.21%), five occurred in children with grade III injuries (6.57%), three occurred in patients with grade II injuries (3.94%), and one occurred in a patient with a grade I injury (1.31%). Conclusion: Based on the severity of the spleen injury, it is difficult to predict the further course of developing complications, but complications are more common in high-grade injuries. The implementation of a follow-up ultrasound protocol is mandatory in all patients with NOM of spleen injuries for the early detection of potentially dangerous and fatal complications.

scholarly journals A Compact Review of Laser Welding Technologies for Amorphous Alloys

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1690
Author(s):  
Jian Qiao ◽  
Peng Yu ◽  
Yanxiong Wu ◽  
Taixi Chen ◽  
Yixin Du ◽  
...  
Keyword(s):  
Amorphous Alloy ◽  
Laser Welding ◽  
Amorphous Alloys ◽  
High Energy ◽  
Industrial Applications ◽  
High Energy Density ◽  
Current Status ◽  
Future Research ◽  
Technological Parameters ◽  
Fast Heating

Amorphous alloys have emerged as important materials for precision machinery, energy conversion, information processing, and aerospace components. This is due to their unique structure and excellent properties, including superior strength, high elasticity, and excellent corrosion resistance, which have attracted the attention of many researchers. However, the size of the amorphous alloy components remains limited, which affects industrial applications. Significant developments in connection with this technology are urgently needed. Laser welding represents an efficient welding method that uses a laser beam with high energy-density for heating. Laser welding has gradually become a research hotspot as a joining method for amorphous alloys due to its fast heating and cooling rates. In this compact review, the current status of research into amorphous-alloy laser welding technology is discussed, the influence of technological parameters and other welding conditions on welding quality is analyzed, and an outlook on future research and development is provided. This paper can serve as a useful reference for both fundamental research and engineering applications in this field.

scholarly journals Short-range Li diffusion vs. long-range ionic conduction in nanocrystalline lithium peroxide Li2O2—the discharge product in lithium-air batteries

2014 ◽  
Vol 7 (8) ◽  
pp. 2739-2752 ◽  
Author(s):  
A. Dunst ◽  
V. Epp ◽  
I. Hanzu ◽  
S. A. Freunberger ◽  
M. Wilkening
Keyword(s):  
Short Range ◽  
Ionic Conduction ◽  
High Energy ◽  
Ion Dynamics ◽  
Nmr Relaxometry ◽  
Lithium Peroxide ◽  
Discharge Product ◽  
Energy Ball ◽  
Spin Locking ◽  
Lithium Air Batteries

Conductivity spectroscopy and 7Li spin-locking NMR relaxometry reveal enhanced ion dynamics in nanocrystalline Li2O2 prepared by high-energy ball milling.

Total scattering experiments on glass and crystalline materials at the ESRF on the ID11 Beamline

2014 ◽  
Vol 30 (S1) ◽  
pp. S2-S8 ◽  
Author(s):  
Andrea Bernasconi ◽  
Jonathan Wright ◽  
Nicholas Harker
Keyword(s):  
High Energy ◽  
Real Space ◽  
European Synchrotron Radiation Facility ◽  
Small Sample ◽  
Distribution Functions ◽  
Total Scattering ◽  
Crystalline Materials ◽  
Space Resolution ◽  
Atomic Pair ◽  
Counting Statistics

ID11 is a multi-purpose high-energy beamline at the European Synchrotron Radiation Facility (ESRF). Owing to the high-energy X-ray source (up to 140 keV) and flexible, high-precision sample mounting which allows small sample–detector distances to be achieved, experiments such as total scattering in transmission geometry are possible. This permits the exploration of a wide Q range and so provides high real-space resolution. A range of samples (glasses and crystalline powders) have been measured at 78 keV, first putting the detector as close as possible to the sample (~10 cm), and then moving it vertically and laterally with respect to the beam in order to have circular and quarter circle sections of diffraction rings, with consequent QMAX at the edge of the detector of about 16 and 28 Å−1, respectively. Data were integrated using FIT2D, and then normalized and corrected with PDFgetX3. Results have been compared to see the effects of Q-range and counting statistics on the atomic pair distribution functions of the different samples. A Q of at least 20 Å−1 was essential to have sufficient real-space resolution for both type of samples while statistics appeared more important for glass samples rather than for crystalline samples.

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