Plasma Generation Research Articles

Emission spectroscopy diagnosis and discharge characteristics distribution analysis of high-frequency, high-enthalpy inductive coupling plasma generator

To study the electromagnetic properties through reentry plasma on ground, a large-sized inductive coupled plasma generator is designed to produce a long-duration, large size and high temperature plasma flow in a low-pressure vacuum tank. Among all plasma parameters, the spatial distribution of electron density and electron temperature is of utmost importance for analyzing the electromagnetic scattering properties. In this study, we used the emission spectroscopy diagnosis method to explore the aforementioned parameters at two locations: upflow and downflow of the discharge coil in the plasma generator. Experiments were conducted under various discharge conditions for argon, with the panel power ranging from 28 kW to 85 kW. The results showed that, at the upflow of the discharge coil, the electron temperature at the center was higher than that at the edge, exhibiting an arch-shaped profile. However, at the downflow of the discharge coil, the electron temperature at the center was lower than that at the edge, exhibiting a saddle-shaped profile. The electron density exhibited a completely opposite distribution compared to the electron temperature, with higher values at the edge for upflow and higher values at the center for downflow. By varying the panel power, we observed the similar phenomenon: the electron temperature decreased, while the electron density increased with the increase in power. Finally, brief analysis was provided at the end of the paper. This study offered valuable insights into the transition of plasma distribution in a plasma generator, providing a reference for future research on the propagation of electromagnetic waves in plasma sheaths.

Intermittency of density fluctuations and zonal-flow generation in MAST edge plasmas

The properties of the edge ion-scale turbulence are studied using the beam emission spectroscopy (BES) diagnostic on MAST. Evidence of the formation of large-scale high-amplitude coherent structures, filamentary density blobs and holes, 2–4 cm inside the plasma separatrix is presented. Measurements of radial velocity and skewness of the density fluctuations indicate that density holes propagate radially inwards, with the skewness profile peaking at 7–10 cm inside the separatrix. Poloidal velocities of the density fluctuations measured using cross-correlation time delay estimation (CCTDE) are found to exhibit an intermittent behaviour. Zonal-flow analysis reveals the presence of poloidally symmetric coherent oscillations – low-frequency (LF) zonal flows and geodesic acoustic modes (GAM). Shearing rates of the observed zonal flows are found to be comparable to the turbulence decorrelation rate. The observed bursts in density-fluctuation power are followed by quiescent periods with a transient increase in the power of sheared flows. Three-wave interactions between broadband turbulence and a GAM are illustrated using the autobispectral technique. It is shown that the zonal flows and the density-fluctuation field are nonlinearly coupled and LF zonal flows mediate the energy transfer from high- to low-frequency density fluctuations.

Application of the Tianwen-1 DOR Signals Observed by Very Long Baseline Interferometry Radio Telescopes in the Study of Solar Wind Plasma and a Coronal Mass Ejection

The Tianwen-1 (TW1) Mars probe experienced solar conjunction for the first time in 2021. The China VLBI Network (CVN) observes the differential one-way ranging (DOR) signals of TW1 throughout its phase. This paper explores the application of CVN observation data to study the solar wind plasma. First, the frequency and phase of the DOR carrier and sidetones at each station are calculated using the Doppler method. Then, the variations in both the differential phase delays (DPD) and the total electron content (TEC) are calculated using the phase of the sidetones. We also statistically analyze the fluctuations in the Delta-DOR (ΔDOR) group delay. The results indicate that the fluctuations of the frequency, phase, ΔDOR group delay, delay rate, and TEC variations of the TW1 signals increase with the decrease of the heliocentric distance. On 2021 November 2, a coronal mass ejection (CME) passed across the ray paths of the telescope beams, when the heliocentric distance and heliographic latitude of the projected position of Mars were 30.6 Rs and 3°, respectively. Our data catch the impact of the CME on the DOR signals. The change of the DPD reaches 170 ps, which is equivalent to 986 TECU. We utilize the cross correlation to analyze the frequency fluctuations at multiple stations, and obtain the propagation direction and velocity variations of the CME. Our analysis indicates that multifrequency DOR signals observed by very long baseline interferometry stations have great application to characterize the electron density variations and propagation of the solar wind plasma.

Influence of the Electrical Characteristics of Pulsed Microwave Magnetron Power Supply on the Conditions for Plasma Formation in the Vacuum Chamber of Resonator-Type Plasmatron

The paper presents the research results of the influence of the electrical characteristics of a pulsed microwave magnetron power supply on the microwave discharge generation conditions, determined by the operating mode of the generating system as a whole. Plasma was formed in a vacuumized reaction-discharge volume located inside a rectangular resonator chamber. Depending on the operating modes of the microwave magnetron power supply, studies have been conducted for three modes of microwave discharge plasma generation: pulsed mode with a duty factor S ≈ 2; pulsed mode with a duty factor S ≈ 1.15; continuous mode. Probe measurements of the microwave power in the microwave discharge plasma volume and its local conductivity have been carried out. The paper presents the dependence of the power of microwave energy in the central area of the reaction-discharge quartz chamber of a microwave plasmotron on the amount of power consumed by the microwave magnetron, as well as the distribution of the electrical component of the microwave discharge plasma along the length and cross-sectional plane of the working volume. It has been established that for all studied modes of operation of the power source, with an increase in the power consumption of the microwave generator system, an increase in the microwave power recorded in the central region of the plasma discharge is characteristic. The continuous generation mode is characterized by a decrease in the uneven distribution of electromagnetic energy along the axis of the discharge chamber. It is shown that the transition from a pulsed to a continuous mode of microwave plasma discharge generation at the same level of power consumption by the generating system is characterized by a decrease in the value of the registered microwave power in the microwave discharge plasma volume and an increase in its local conductivity in particular areas of the reaction-discharge volume.

NXT007-mediated hemostatic potential is suppressed by activated protein C-catalyzed inactivation of activated factor V

BackgroundActivated protein C (APC) inactivates activated factor (F) V (FVa) and FVIIIa. NXT007, an emicizumab-based engineered therapeutic bispecific antibody, enhances the coagulation potential of FVIII-deficient plasma (FVIIIdef-plasma) to near normal levels. However, little is known about the effect of APC-induced inactivation in NXT007-mediated hemostatic function. ObjectivesTo investigate the contribution of APC-mediated reactions to NXT007-driven hemostasis. MethodsIn pooled normal plasma (PNP) or FVIIIdef-plasma spiked with NXT007 (10 μg/mL), effects of APC (0-16 nM) were measured using a thrombin generation assay (TGA). The direct effects of APC on cofactor activity of NXT007 or FVIIIa in a FXa generation assay were also measured. The FVdef-plasma and FV Leiden plasma (FVLeiden plasma) were preincubated with 2 anti-FVIII monoclonal antibodies (termed FVIII-depleted), and the APC effect in the presence of NXT007 in FVIII-depleted FVdef-plasma with the addition of exogenous FV (7.5-30 nM) or FVIII-depleted FVLeiden plasma was investigated. ResultsThe APC dose-dependent suppression effect in TGA of FVIIIdef-plasma spiked with NXT007 was similar to that of PNP. FXa generation with NXT007 was not impaired by the addition of APC, suggesting that the APC-induced reaction in TGA with NXT007 was attributed to the direct inactivation of FVa. The addition of APC to FVIII-depleted FVdef-plasma, along with NXT007 and various FV concentrations, showed a similar attenuation to PNP. The NXT007-driven thrombin generation in FVIII-depleted FVLeiden plasma was suppressed by APC, similar to the reaction in native FVLeiden plasma. ConclusionNXT007 did not impair APC-mediated downregulation of FVa in FVIIIdef-plasmas, regardless of the presence of FV mutation with APC resistance.

Magnetic whispering-gallery super-resonance spoiling in a Drude-Kerr optical cavity

High-quality optical Fano resonances, which exist in a spherical dielectric microparticle in the spatial configurations of the whispering-gallery like modes (WGMs) and recently are referred to as the “super-resonances”, possess extremal sensitivity not only to the micro-cavity size and shape but also to the optical properties of the particulate material. The increase in the power of light radiation coupling into a WGMs can lead to the manifestation of strong optical nonlinearity of the resonator material due to the cubic nonlinearity (optical Kerr effect) and generation of free electron plasma in certain regions of the spherical microcavity. In fact, an optically linear medium of the resonance cavity transforms into a Drude-Kerr-type medium with a strong dependence on input laser intensity. With the help of the finite-elements numerical simulations, we theoretically analyze the transformations of the resonant contour for a number of high-quality WGMs-like excited in a lanthanum-glass microsphere exposed to an optical radiation of different intensity. We show that in a certain input intensity range, the competition of Kerr and plasma optical nonlinearities can stop and even reverse the Stokes shift of the super-resonance observed in a pure Kerr medium. Additionally, optical ionization and plasma generation within the mode volume significantly reduce the strength of the magnetic super-resonance and lead to its spoiling and frequency splitting. Our findings pav the way for an all-optical approach for the obtaining the strong magnetic fields of the order of tens Tesla at relatively moderate laser intensities without the use of structured laser beam.

Influence mechanisms of electron beam irradiation on surface flashover in vacuum: Electron modification, deposition, and migration

In surface science, surface flashovers are discharge phenomena that occur at the gas/vacuum-solid interface. Spacecraft in the universe suffers from high-energy electron irradiation while it works under a high DC operating voltage, and thus, surface flashover threatens the safe operation of spacecraft and limits human’s deeper exploration of the universe. To unravel the influence mechanisms of electron beam irradiation (EBI), surface flashover voltages (Vf) of epoxy composites during EBI, short-term after EBI, and long-term after EBI are investigated, and the behaviors of molecular structure, deposited electrons near chains, and radiation electrons under EBI and their effects on Vf are separately clarified. For long-term after EBI, EBI induces crosslinking of molecular chains and introduces deep traps to the solid surface, which impedes electron emission and surface charging, and thus Vf increases. For short-term after EBI, the deposited electrons suppress charge injection to the solid, and Vf further increases. During EBI, the high-energy radiation electrons stimulate gas desorption and directly participate in plasma propagation, leading to a sharp decrease in Vf. This work comprehensively explains the influence mechanisms of EBI electron modification, deposition, and migration on the Vf, which offers a theory to guide the prevention of flashover for spacecraft.

Computational study of a microwave plasma reactor based on the TM112 mode for diamond deposition

One of the main features of microwave plasma reactors is the electric field structure in the resonant cavity, which must be both intense and uniform in front of the substrate. For this reason, transverse magnetic modes are often used, especially axisymmetric modes because they produce an axisymmetric plasma. Microwave plasma reactors can be differentiated according to the chosen mode, because this has a direct influence on the diamond film growth process, among other features such as the coupling technique and the used quartz window. Another attractive characteristic of said reactors is obtaining large activation areas of the plasma. In this paper, we propose a microwave plasma reactor based on the TM112 cylindrical mode, which is subject to a computational study. Unlike axisymmetric modes, which activate the plasma on the cavity axis, the TM112 cylindrical mode presents two activation plasma areas. The reactor was designed following the methodology described by Silva et al., and using the Plasma, Radiofrequency (RF), and Heat transfer modules of the software COMSOL Multiphysics. The obtained results are presented in two stages. The first one is related to the initial electric field distribution of the TM112 mode. Next, the generation of the hydrogen plasma was simulated from the interaction of H2 gas with the TM112 microwave field. The plasma activation process is described in detail from graphics of the time evolution of the electron density, hydrogen density, and their respective temperatures until a steady state is reached. Additionally, the influence of the pressure on the concentration and the temperature of both electrons and gas in a steady state is analyzed. The presented results can be useful for the design of plasma reactors for diamond deposition.

Innovative Curved-Tip Reactor for Non-Thermal Plasma and Plasma-Treated Water Generation: Synergistic Impact Comparison with Sodium Hypochlorite in Dental Root Canal Disinfection.

Non-thermal plasmas (NTPs), known as cold atmospheric plasmas (CAPs), hold great potential for diverse medical applications, including dentistry. However, traditional linear and rigid dielectric barrier discharge reactors used for NTP generation encounter limitations in accessing oral cavities and root canals. To address this issue, we have developed an innovative NTP reactor featuring an angled end for improved accessibility. The central copper electrode, with a 0.59 mm diameter and adjustable length for desired angulation, is coated with zircon powder (ZrSiO4) to ensure stable NTP generation. This central electrode is housed within a stainless steel tube (3 mm internal diameter, 8 mm external diameter, and 100 mm length) with a 27° angle at one end, making it ergonomically suitable for oral applications. NTP generation involves polarizing the reactor electrodes with 13.56 MHz radio frequency signals, using helium gas as a working medium. We introduce plasma-treated water (PTW) as an adjunctive therapy to enhance biofilm eradication within root canals. A synergistic approach combining NTP and PTW is employed and compared to the gold standard (sodium hypochlorite, NaOCl), effectively neutralizing Enterococcus faecalis bacteria, even in scenarios involving biofilms. Moreover, applying NTP in both gaseous and liquid environments successfully achieves bacterial inactivation at varying treatment durations, demonstrating the device's suitability for medical use in treating root canal biofilms. The proposed NTP reactor, characterized by its innovative design, offers a practical and specific approach to plasma treatment in dental applications. It holds promise in combatting bacterial infections in root canals and oral cavities.

On Encapsulated Dielectric Barrier Discharge Plasma Sources for Radar Cross Section Reduction in Mobile Environments.

This paper deals with the practical application of Radar Cross Section (RCS) reduction technology using plasma. Although various plasma application technologies for RCS reduction have been studied, there are still many issues to be addressed for practical implementation. In order to achieve actual application, the discharge should be sustained regardless of the external environment of the aircraft. It is also important to investigate the actual plasma parameters to determine the expected RCS reduction effect. Building upon previous studies that optimized the electrodes for RCS reduction, this study fabricates a Dielectric Barrier Discharge (DBD) source suitable for dynamic environments and verifies the power consumption during one cycle of plasma generation. The obtained results are expected to contribute to the optimization of DBD electrodes for plasma RCS reduction.

Measuring Thrombin Generation in Platelet Rich Plasma with the ST Genesia

Background: Thrombin generation (TG) is nowadays used more and more for diagnosing and monitoring of patients. The ST Genesia is a fully automated device for measuring TG in platelet poor plasma (PPP). As the samples are not being inverted prior to the measurement once loaded in the device, it was not known whether it was possible to measure TG in platelet rich plasma (PRP). Platelets can sediment in time possibly affecting TG results. The goal of this study was to evaluate the use of the ST Genesia for measuring TG in PRP in time and to investigate whether the assay is sensitive to platelet antagonists. Methods: Blood was taken from 6 healthy donors and PRP was immediately prepared by centrifuging the blood once for 15 minutes at 220g. The PRP was divided into 14 tubes: 11 tubes for measuring TG in time; i.e. after 0, 15, 30, 45, 60, 75, 90, 105, 120, 180, 240 minutes after the samples were loaded on board; 1 tube for platelet count measurement, 1 tube for TG with the Calibrated Automated Thrombogram (CAT) assay and 1 tube for freezing the PRP. The PRP reagent of the CAT assay was used for triggering TG that contains a low tissue factor concentration. Tukey's multiple comparisons test was used for statistical analysis. Results: The platelet count remained stable in time even without inverting the vial prior to the measurement up to 3 hours. After 4 hours, platelet count was significantly lower (p<0.01). TG in PRP remained stable in time up to 3 hours, after that lagtime and time-to-peak were extended by an average of 48% and 16%, respectively (p-values <0.0001 and 0.0121, respectively), while ETP and peak height remained stable (with low CV's of <6.0% and <7.3%, respectively). The ST Genesia proved to be sensitive to platelet antagonists aspirin (100µM) and Cangrelor (500nM) as peak height decreased with 22% and 24%, respectively. TG measured with the CAT and the ST Genesia was comparable. Measuring TG in PRP after being frozen at -80°C resulted TG kinetics similar to TG in PPP, with a shorter lagtime (-67%) and time-to-peak (-64%), with an increased peak height (+82%), and velocity index (+383%), and an unaffected ETP. Conclusion: The ST Genesia can be used for the reproducible measurement of TG in PRP up to two hours after loading the samples in the device.

Impact of environmental oxygen on nanoparticle formation and agglomeration in aluminum laser ablation plumes.

The role of ambient oxygen gas (O2) on molecular and nanoparticle formation and agglomeration was studied in laser ablation plumes. As a lab-scale surrogate to a high explosion detonation event, nanosecond laser ablation of an aluminum alloy (AA6061) target was performed in atmospheric pressure conditions. Optical emission spectroscopy and two mass spectrometry techniques were used to monitor the early to late stages of plasma generation to track the evolution of atoms, molecules, clusters, nanoparticles, and agglomerates. The experiments were performed under atmospheric pressure air, atmospheric pressure nitrogen, and 20% and 5% O2 (balance N2), the latter specifically with in situ mass spectrometry. Electron microscopy was performed ex situ to identify crystal structure and elemental distributions in individual nanoparticles. We find that the presence of ≈20% O2 leads to strong AlO emission, whereas in a flowing N2 environment (with trace O2), AlN and strong, unreacted Al emissions are present. In situ mass spectrometry reveals that as O2 availability increases, Al oxide cluster size increases. Nanoparticle agglomerates formed in air are found to be larger than those formed under N2 gas. High-resolution transmission electron microscopy demonstrates that Al2O3 and AlN nanoparticle agglomerates are formed in both environments; indicating that the presence of trace O2 can lead to Al2O3 nanoparticle formation. The present results highlight that the availability of O2 in the ambient gas significantly impacts spectral signatures, cluster size, and nanoparticle agglomeration behavior. These results are relevant to understanding debris formation in an explosion event, and interpreting data from forensic investigations.

Mg Ion Plasma Generated by a High Magnetic Field in a Microwave Resonator

The generation and reduction reaction of magnesium plasma were studied using a cylindrical transverse magnetic-mode applicator in magnetic and electric field modes. By heating Mg powder using the magnetic field mode, plasma was generated with the evaporation of Mg and stably sustained. When the Mg plasma sample was introduced into the reaction zone and exposed to microwave and lamp heating, a reduction reaction of scandium oxide also occurred. The results of this study provide prospects for the development of a larger microwave refining system.

The discharge characteristics and benzene degradation performance of a three-electrode DBD reactor powered by dual AC power generators

A three-electrode hybrid volume/surface dielectric barrier discharge (V-SDBD) configuration with two plane electrodes and six grounded strips electrode was designed for enhancing the generation of discharge plasma to degrade gaseous benzene. Two plane electrodes were separately powered by a 5 kHz AC generator and a 50 Hz AC generator, respectively. Compared with the typical two-electrode volume DBD (VDBD) reactor excited by 50 Hz AC generator, the hybrid V-SDBD reactor has lower onset discharge voltage and better discharge homogeneity, and the benzene degradation efficiency of V-SDBD was 1.12 times higher than that of VDBD at a similar energy efficiency. Moreover, an increase in the voltage on HVE-II promoted benzene degradation, but decreased the energy efficiency of benzene degradation.

Spherical TiAl Alloy Powders by PREP: Preparation, Microstructure and Properties

TiAl alloy powders were prepared by plasma rotate electrode pulverization (PREP) with high speed. The effect of preparation process on the microstructure and properties of powders was studied. The results showed that the titanium aluminum powder prepared by PREP method was solid and spherical without satellite powder. The powders had two morphologies: cracked surface and smooth surface. The relationship between particle size and surface morphology was as follows: the smaller the particle size, the smoother the surface. Ti, Nb and Gr elements were uniformly distributed, while Al elements were segregated, but no alloy element loss occurred. The powderswere mainly composed of γ-TiAl and α2-Ti3Al phase and contained a small amount of NbCr2 phase. The average thickness of laminates of α 2+γ was about 0.2μm. Thelamellar thickness of γ phase was about 20nm. The long axis of NbCr2 phase was 200nm, and the short axis was 50 ~ 100nm. The higher the rotating speed of the electrode, the smaller the particle size and the higher the sphericity of the powders. With the increase of plasma generator current, the particle size decreased and the sphericity increased. The yield of - 100 mesh ~ + 325 mesh powders for EBSM molding could reach more than 80.68 %, when42000r / min and 670A process parameters were adopted.

Detailed and simplified plasma models in combined-cycle magnetohydrodynamic power systems

Magnetohydrodynamics (MHD) is a subject concerned with the dynamics of electrically conducting fluids (plasma) and can be applied in electric power generation. As a unique technology for producing direct-current electricity without moving parts, it can be utilized within a high-temperature topping power cycle to be combined with a traditional bottoming power cycle, forming a combined-cycle MHD system. This study presents governing equations for the electric field and current density field within a moving plasma subject to an applied magnetic field. The modeling equations are described at four descending levels of complexity. Starting with the first level of modeling, which is the most general case, where no assumptions are made regarding the electric field, plasma velocity field, applied magnetic field, or electrode geometry. In the second level of modeling, the magnetic field is treated as one-dimensional. In the third level of modeling, a specific Faraday-type magnetohydrodynamics plasma generator channel is considered, having two continuous electrodes acting as parallel constant-voltage terminals. In the fourth (and simplest) level of modeling, an additional approximation is made by setting the Hall parameter to zero and replacing all vector fields with scalar quantities. For that simplest model, a representative set of operation conditions (electric conductivity 20 S/m, temperature 2800 K, supersonic plasma gas speed 2000 m/s with Mach 2.134, and magnetic flux density 5 T) shows that the optimum idealized electric power that can be extracted from a unit volume of plasma is estimated as 500 MW/m3. This is a much larger volumetric power density than typical values encountered in reciprocating piston-type engines (0.2 MW/m3) or rotary gas turbine engines (0.5 MW/m3). Such an extremely high power density enables very compact power generation units.

A review on dielectric barrier discharge nonthermal plasma generation, factors affecting reactive species, and microbial inactivation

Nonthermal plasma treatment has been proven effective in decontaminating microorganisms in various foods on a laboratory scale. Various techniques for creating plasma have been investigated extensively due to their potential application in multiple settings; one of these methods is dielectric barrier discharge. This article summarizes our current understanding of plasma physics, different methods for producing plasma, the resulting reactive species, and their role in microbial degradation. The effect of plasma treatment on the inactivation of microorganisms is discussed, along with the intrinsic and extrinsic factors involved. In addition, the use of dielectric barrier discharge plasma in microbial destruction in various foods, as well as the effect of the treatment on other relevant properties, is also addressed.

Linear Plasma Device for the Study of Plasma–Surface Interactions

At the research and production company “PlasmaScience” (Ust-Kamenogorsk, Kazakhstan), a linear plasma generator installation, KAZ-PSI (Kazakhstan Plasma Generator for Plasma Surface Interactions), has been developed and constructed for the study of the interaction of plasma and materials. This article outlines some features of the developed experimental installation designed for the investigation of surface–plasma interactions. The primary components of the linear plasma installation include an electron-beam gun with a LaB6 cathode, a plasma-beam discharge chamber, an interaction chamber, a target device, and an electromagnetic system comprising electromagnetic coils. The KAZ-PSI unit enables continuous plasma generation using hydrogen, deuterium, helium, argon, and nitrogen. The electron density of the plasma is in the range of about 1017–1018 m−3 and the electron temperature is in the range of 1 to 20 eV. The incident ion energy is regulated by applying a negative potential of up to 2 kV to the target. Experiments on the irradiation of tungsten with helium plasma were carried out using the KAZ-PSI installation for the first time. This article presents the research findings on the structure and properties of tungsten relative to the temperature of helium plasma irradiation. Alterations in roughness, microstructure, hardness, modulus of elasticity, and erosion of the tungsten’s surface following helium plasma irradiation at varying temperatures were examined. The study’s results indicate that helium plasma irradiation induces changes in the morphology of the tungsten’s surface, creating surface relief due to sputtering by helium ions, as well as the formation of blisters. Mechanical testing revealed that after irradiation at T = 500 °C, there was an increase in hardness of up to 10%, and a slight decrease in modulus of elasticity. And after irradiation at T = 900 °C and T = 1300 °C, both hardness and elastic modulus decreased with rising temperature. The tungsten surface erosion evaluation results showed that the degrees of surface erosion increase with increasing target temperature.

Influence of emicizumab on protein C-mediated clotting regulation

Emicizumab, a FVIII-mimetic bispecific antibody, is insensitive to degradation by activated protein C (APC) and may thus induce a procoagulant state. We investigated the effect of emicizumab on protein C-mediated inhibition of coagulation under in vitro conditions mimicking physiological and pathological clotting activation. Thrombin generation (TG) in tissue factor-triggered hemophilic plasma containing emicizumab (50 μg/mL) was inhibited by APC or thrombomodulin in a concentration-dependent manner, and to a similar extent as in plasma added with FVIII (Kovaltry, 1 IU/mL). However, when clotting was activated via the intrinsic pathway, emicizumab-plasma displayed resistance to APC, manifested by a barely detectable prolongation of the lag time of TG, and by the lack of inhibition of FXa generation. Moreover, in contact-activated plasma added with APC, the generation of a second wave of thrombin, following prothrombin replenishment, was much greater in emicizumab-plasma than in Kovaltry-plasma, suggesting that the insensitivity of emicizumab to APC may translate in greater thrombin formation. Considering the major role played by the contact system in the thrombotic process, hemophilia A patients under emicizumab treatment might be at increased thrombotic risk.

Spectroscopic Diagnostic of Laser-Induced Zn Plasma

The sample's physical characteristics and laser parameters impact the generation and characterization of Laser-Induced Plasma (LIP), which is a relevant phenomenon in many applications. We investigated the effect of laser energy on laser-induced Zn plasma characterization in this study. A Zn plasma with a repeating frequency of 6 Hz, a first wavelength of 1064 nm, a pulse duration of 10 ns, and a laser energy range of 300 mJ to 500 mJ was created using a Q-switched ND: YAG laser. The basic plasma properties, such as electron temperature and density, were estimated using optical emission spectroscopy (OES). The electrons' temperature was measured by the Boltzmann plot method, and the value of the electrons' temperature ranged from 1.6 eV to 2.051 eV in the laser energy range (300-500) mJ. In electron density estimation using the Stark broadening methods, the density value range from 12.75×1017 cm-3 to 19.50×1017 cm-3, in laser energy range (300-500 ) mJ. In addition, various plasma characteristics such as plasma frequency (fp), the number of particles in the Debye sphere (ND), and Debye length (λD) were estimated. We found that laser energy affects every plasma parameter.