Mechanism of soft x-ray continuum radiation from low-energy pinch discharges of hydrogen and ultra-low field ignition of solid fuels

EUV continuum radiation(10–30 nm) arising only from very low energy pulsed pinch gas discharges comprising some hydrogen was first observed at Black Light Power, Inc. and reproduced at the Harvard Center for Astrophysics(Cf A). The source was determined to be due to the transition of H to the lower-energy hydrogen or hydrino state H(1/4) whose emission matches that observed wherein alternative sources were eliminated. The identity of the catalyst that accepts 3 · 27.2 eV from the H to cause the H to H(1/4) transition was determined to HOH versus 3H. The mechanism was elucidated using different oxide-coated electrodes that were selective in forming HOH versus plasma forming metal atoms as well as from the intensity profile that was a mismatch for the multi-body reaction required during 3H catalysis. The HOH catalyst was further shown to give EUV radiation of the same nature by igniting a solid fuel comprising a source of H and HOH catalyst by passing a low voltage, high current through the fuel to produce explosive plasma. No chemical reaction can release such high-energy light. No high field existed to form highly ionized ions that could give radiation in this EUV region that persisted even without power input. This plasma source serves as strong evidence for the existence of the transition of H to hydrino H(1/4) by HOH as the catalyst and a corresponding new power source wherein initial extraordinarily brilliant light-emitting prototypes are already producing photovoltaic generated electrical power. The hydrino product of a catalyst reaction of atomic hydrogen was analyzed by multiple spectroscopic techniques. Moreover, the m H catalyst was identified to be active in astronomical sources such as the Sun, stars and interstellar medium wherein the characteristics of hydrino match those of the dark matter of the Universe.     

Study on Fragments Emission in the 64Ni+64Ni Reaction at 40 AMeV

The multiplicity of fragments in Fermi energy heavy-ion collisions was experimen-tally extracted. Compared with the results of calculation using the antisymmetrized molecular dynamics (AMD) model which accounts for the primary fragments only, the results calculated using the AMD together with a statistical decay code GEMINI to account for the deexcitation of excited primary fragments are in better agreement with those extracted from the experiment. This observation indicates that the experimental multiplicity distribution may be significantly different from those of primary fragments.     

A new model of the L–H transition and H-mode power threshold

In order to understand the mechanism of the confinement bifurcation and H-mode power threshold in magnetically confined plasma,a new dynamical model of the L–H transition based on edge instability phase transition(EIPT) has been developed.With the typical plasma parameters of the EAST tokamak,the self-consistent turbulence growth rate is analyzed using the simplest case of pressure-driven ballooning-type instability,which indicates that the L–H transition can be caused by the stabilization of the edge instability through EIPT.The weak E?×?B flow shear in L-mode is able to increase the ion inertia of the electrostatic motion by increasing the radial wave number of the tilted turbulence structures,which play an important role for accelerating the trigger process of EIPT rather than directly to suppress the turbulent transport.With the acceleration mechanism of E?×?B flow shear,fast L–H and H–L transitions are demonstrated under the control of the input heating power.Due to the simplified scrape-offlayer boundary condition applied,the ratio between the heating powers at the H–L and L–H transition respectively differs from the ratio by Nusselt number.The results of the modeling reveal a scaling of the power threshold of the L–H transition,P_(L-H)?∝?n~(0.76) B~(0.8) for deuterium plasma.It is found finite Larmor radius induces an isotope effect of the H-mode power threshold.     

Charging Effect in Plasma Etching Mask of Hole Array

It has already been found that the round shape of holes can be changed into hexagonal shape during plasma etching processes.This work aims to understand the mechanism behind such a shape change using particle simulation method.The distribution of electric field produced by electrons was calculated for different heights from the mask surface.It is found that the field strength reaches its maximum around a hole edge and becomes the weakest between two holes. The field strength is weakened as moving away from the surface.The spatial distribution of this electric field shows obvious hexagonal shape around a hole edge at some distances from the surface. This charging distribution then affects the trajectories of ions that fall on a mask surface so that the round hole edge is etched to become a hexagonal hole edge.The changing of this hole shape will again alter the spatial distribution of electric field to enhance the charging effect dynamically.     

Spontaneous current relaxation in NBI heated plasmas on EAST

We report on current profile evolution in EAST NBI driven plasmas where two neutral beams are injected,one during the current ramp phase and the second during flattop.At the end of the current ramp phase,it is found that a flat q profile with q0?~?1 is achieved with low magnetic shear in the core.It is observed that plasma current and density both relax much faster than resistive time,even in the absence of sawtooth activity when H–L transition occurs.Density fluctuations associated with magnetic perturbations(3/2) as a precursor to the H–L transition are observed.It is likely that these modes play a role in fast current transport.     

Characteristics of Droplets Ejected from Liquid Propellants Ablated by Laser Pulses in Laser Plasma Propulsion

The angular distribution and pressure force of droplets ejected from liquid water and glycerol ablated by nanosecond laser pulses are investigated under different viscosities in laser plasma propulsion. It is shown that with increasing viscosity, the distribution angles present a decrease tendency for two liquids, and the angular distribution of glycerol is smaller than that of water. A smaller distribution leads to a higher pressure force generation. The results indicate that ablation can be controlled by varying the viscosity of liquid propellant in laser plasma propulsion.     

Kinetic-theory-based investigation of electronegative plasma–wall transition with two populations of electrons

Kinetic theory has been employed to investigate the magnetized plasma-sheath structure and its characteristics in the presence of more than one species of negatively charged particles: hot electrons,cold electrons, and negative ions. The cold electrons and negative ions are considered to obey a Maxwellian distribution, whereas the hot electrons follow a truncated Maxwellian distribution. The Bohm sheath condition has been extended for the case of more than one species of negatively charged particles, in which the concentration of hot electrons has a crucial role in achieving the Bohm velocity. The thermal motion of hot electrons is much higher compared to cold electrons and negative ions, such that the variation of hot electron concentrations and the temperature ratio of hot to cold electrons play a key role in the determination of the plasma-sheath parameters: particle densities,electrostatic potential, the flow of positive ions towards the wall, and sheath thickness. We have estimated the deviation of the resultant drift velocity of positive ions on the plane perpendicular to the wall from the parallel component at the presheath–sheath interface. It is found that the deviation between the two velocity components increases with an increase in the obliqueness of the magnetic field. Furthermore, the results obtained from the kinetic trajectory simulation model are compared with the results obtained using a fluid model; the results are qualitatively similar, although the potential varies by less than 4% in terms of the magnitude at the wall.     

22 MeV polarized proton scattering from 40Ca and effective NN interactions

Analyzing powers and differential cross sections have been measured for elastic scattering of 22 MeV polarized protons from ^40Ca ,^16O and ^12C ,and differential cross sections for inelastic scattering of 22MeV protons from 3^-(3.736 MeV)and 5^-(4.491 MeV) states of ^40Ca have also been measured .The experimental data for polarized proton elastic scattering have been analyzed with a phenomenological optical potential parameters,the experimental data and theoretical values are in good agreement .In the theoretical frome of microscopic single scattering model,transition densities extracted from electron inelastic scattering and M3Y and Halderson‘s effective interactions have been utilized to analyze the experimental data of 22 MeV proton inelastic scattering from ^40Ca.Overall,it seems that Halderson‘s effective interaction can better describe the experimental data than M3Y although the degree of agreement between experimental and theoretical values needs to be improved.     

Temperature manipulating peptide self-assembly in water nanofilm

Peptide GAV-9 is derived from 3 different disease related proteins. The self-assembly of GAV-9 in a water nanofilm attracted much attention recently. We studied how the temperature factor influenced the peptide selfassembly in a water nanofilm and found interesting phenomena: 1) the higher the temperature, the faster the nanofilaments grow; 2) the GAV-9 peptide formed double monolayers in a water nanofilm at 60℃, which further supports the hypothesis that the water nanofilm could change the hydrophobicity of mica. We believe these results can help not only the microcontact printing of amyloid peptides, but also a better understanding on how temperature controls the properties of water nanofilm.     

Numerical Simulation of VHF Effects on Densities of Important Species for Silicon Film Deposition at Atmospheric Pressure

The characteristics of homogeneous discharges in mixed gases of hydrogen diluted silane and argon at atmospheric pressure are investigated numerically based on a one-dimensional fluid model.This model takes into account the primary processes excitation and ionization,sixteen reactions of radicals with radicals in silane/hydrogen/argon discharges and therefore,can adequately represent the discharge plasma.We analyze the effects of very high frequency(VHF) on the densities of species(e,H,SiH3,SiH+3 and SiH2) in such discharges using the model.The simulation results show that the densities of SiH3,SiH+3,H,and SiH2 increase with VHF when the VHF ranges from 30 MHz to 150 MHz.It is found that the deposition rate of μc-Si:H film depends on the concentration of SiH3,SiH+3,SiH2,and H in the plasma.The effects of VHF on the deposition rate and the amount of crystallized fraction for μc-Si:H film growth is also discussed in this paper.     

Energy and centrality dependence of light nuclei production in relativistic heavy-ion collisions

We study the energy and centrality dependence of deuteron and triton（helium-3） production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider（RHIC） and CERN Large Hadron Collider（LHC）using the Tsallis distribution, blast-wave（BW） model, and stationary Fokker-Planck（FP） solution. Our study shows that good agreement can be reached between the fitting results from the stationary FP solution and the experimental data for Au + Au collisions from the beam energy scan（BES） p...     

Theoretical investigation of uranium(Ⅳ) coordinated with N,N'-bis(3-allyl salicylidene)-o-phenylenediamine

We used density functional theory calculations at the B3LYP/6-311G** level for a theoretical study on the complex formed when uranium(Ⅳ) coordinates with N,N'- bis(3-allyl salicylidene)-o-phenylenediamine(BASPDA),i.e.,U(BASPDA)_2.The results indicated that the coordination complex of U(BASPDA)2 could form two different structures with a ratio of 1:2.One was a parallel dislocation structure(PDS-U),in which the two BASPDAs' middle benzene rings adopted a parallel dislocation with an angle of 56.64°,and the other was a staggered finger "+" structure(SFS-U),in which the two BASPDAs employed the staggered finger "+" shape.The binding energies,charge distribution,spectral properties,thermodynamic properties,molecular orbitals and Wiberg bond indices for both PDS-U and SFS-U were calculated and compared with each other.     

A Circumstantial Evidence for the Possible Production of QGP in the 158 AGeV/c Central Pb Pb Collisions

One of the aims to research relativistic heavy-ion collisions is to explore the probability of quark-gluon plasma phase transition from normal nuclear matter. Hadron and string cascade model (JPCIAE) ,based on the hypothesis without introducing the quark-gluon plasma (QGP), is employed to study the direct photon and π 0 transverse momentum distributions for central 208Pb 208Pb collisions at 158 AGeV/c; The theoretical results of transverse momentum distribution for both the direct photon and the π0 particle are lower than the data of WA98 experiment. Having considered the fact that the     

Estimation of the Lyman-α signal of the EFILE diagnostic under static or radiofrequency electric field in vacuum

The electric field induced Lyman-α emission diagnostic aims to provide a non intrusive and precise measurement of the electric field in plasma, using a beam of hydrogen atoms prepared in the metastable 2 s state. The metastable particles are obtained by means of a proton beam extracted from a hydrogen plasma source, and neutralised by interaction with vaporised caesium.When a 2 s atom enters a region where an electric field is present, it undergoes a transition to the2 p state(Stark mixing). It then quickly decays to the ground level, emitting Lyman-α radiation,which is collected by a photomultiplier. The 2 s→2 p transition rate is proportional to the square of the magnitude of the electric field, and depends on the field oscillation frequency(with peaks around 1 GHz). By measuring the intensity of the Lyman-α radiation emitted by the beam it is possible to determine the magnitude of the field in a defined region. In this work, an analysis of the behaviour of the diagnostic under static or radiofrequency electric field is presented. Electric field simulations obtained with a finite element solver of Maxwell equations, combined with theoretical calculations of the Stark mixing transition rate, are used to develop a model for the interpretation of photomultiplier data. This method shows good agreement with experimental results for the static field case, and allows to measure the field magnitude for the oscillating case.     

The Distortion of Energy Deposit Distribution of (12)～C Ions in Water

The transport process of 12C ions in water was studied with SRIM code and Geant4 toolkit.The SRIM results indicate that the transverse diffusion of 12C ion beam causes distortion of energy deposit along the beam direction.The distortion becomes more notable as the trans-verse diffusion increases.The simulation results of Geant4 indicate that the influence of secondary fragments on energy deposit distribution would be the main factor causing the distortion in higher energy range.In the region adjacent to the beam line where the contribution from 12C ions domi-nates,the contributions from secondary fragments are ignorable.The further from the beam axis the region locates,the larger the contributions from secondary fragments,until the contributions from secondary fragments are ignorable.The further from the beam axis the region locates,the larger the contributions from secondary fragments,until the contributions from secondary frag-ments exceed that of 12C.Among all the secondary fragments,the contributions of H,He and B ions are mostly notable.It is also found that some positron-emitting secondary fragments could be very useful for position emitting tomography (PET).     

Thermal analysis and tests of W/Cu brazing for primary collimator scraper in CSNS/RCS

To the transverse beam collimation system in a rapid cycling synchrotron,an important component is the primary collimator,which improves emittance of the beam halo particles such that the particles outside the predefined trajectory can be absorbed by the secondary collimators.Given the material properties and power deposition distribution,the beam scraper of the primary collimator is a0.17 mm tungsten foil on a double face-wedged copper block of 121.5 mm x 20 mm.The heat is transferred to the outside by a φ34 mm copper rod.In this paper,for minimizing brazing thermal stress,we report our theoretical analysis and tests on brazing the tungsten and copper materials which differ greatly in size.We show that the thermal stress effect can be controlled effectively by creating stress relief grooves on the copper block and inserting a tungsten transition layer into the copper block.This innovation contributes to the successful RD of the primary collimator.And this study may be of help for working out a brazing plan of similar structures.     

Advanced oxidation technology for H2S odor gas using non-thermal plasma

Non-thermal plasma technology is a new type of odor treatment processing. We deal with H2S from waste gas emission using non-thermal plasma generated by dielectric barrier discharge. On the basis of two criteria, removal efficiency and absolute removal amount, we deeply investigate the changes in electrical parameters and process parameters, and the reaction process of the influence of ozone on H2S gas removal. The experimental results show that H2S removal efficiency is proportional to the voltage, frequency, power, residence time and energy efficiency,while it is inversely proportional to the initial concentration of H2S gas, and ozone concentration. This study lays the foundations of non-thermal plasma technology for further commercial application.     

Projectile fragment emission in the fragmentation of ~(56)Fe on Al,C,and CH_2 targets

The emission angle distribution of projectile fragments (PFs) and the temperature of PF emission sources for fragmentation of 56Fe on polyethylene,carbon,and aluminum targets at the highest energy of 497 A MeV are investigated on the basis of corrected data,using a CR-39 plastic nuclear track detector.It is found that the average emission angle of PFs increases with the decrease in PF charge for the same target,and no obvious dependence of angular distribution on the mass of the target nucleus is found for the same PF.The cumulative squared transverse momentum distribution of PFs can be well represented by a single Rayleigh distribution.The temperature of PF emission sources is extracted from the distribution,and it is about 1.0-8.0 MeV and does not depend on the mass of the target for PFs with charges of 9≤Z≤25.     

Interferometry analyses of pion and kaon for the granular sourcesfor Au+Au collisions at -------sNN√ =200 GeV

We examine the interferometry results of identi-cal pion and kaon for the granular sources of quark–gluon plasma droplets for the Au+Au collisions at------sNN√ =200 GeV. The effects of particle absorptions of pion and kaon on the results are investigated. We find that the absorptions lead to the decrease of the interferometry radii. After considering the absorptions, the interferometry radii of pion and kaon of the granular sources are in better agreement with the experimental data of the Au+Au collisions.     

Transition toward thorium fuel cycle in a molten salt reactor by using plutonium

The molten salt reactor(MSR), as one of the Generation Ⅳ advanced nuclear systems, has attracted a worldwide interest due to its excellent performances in safety, economics, sustainability, and proliferation resistance. The aim of this work is to provide and evaluate possible solutions to fissile 233 U production and further the fuel transition to thorium fuel cycle in a thermal MSR by using plutonium partitioned from light water reactors spent fuel. By using an in-house developed tool, a breeding and burning(BB) scenario is first introduced and analyzed from the aspects of the evolution of main nuclides, net 233 U production, spectrum shift, and temperature feedback coefficient. It can be concluded that such a Th/Pu to Th/~(233)U transition can be accomplished by employing a relatively fast fuel reprocessing with a cycle time less than 60 days. At the equilibrium state, the reactor can achieve a conversion ratio of about 0.996 for the 60-day reprocessing period(RP) case and about 1.047 for the 10-day RP case.The results also show that it is difficult to accomplish such a fuel transition with limited reprocessing(RP is 180 days),and the reactor operates as a converter and burns the plutonium with the help of thorium. Meanwhile, a prebreeding and burning(PBB) scenario is also analyzed briefly with respect to the net 233 U production and evolution of main nuclides. One can find that it is more efficient to produce 233 U under this scenario, resulting in a double time varying from about 1.96 years for the 10-day RP case to about 6.15 years for the 180-day RP case.