RADIATION EFFECT ON FLUORINATED SiO2 FILMS

A systematic investigation of γ radiation effects in gate SiO2 as a function of the fluorine ion implantation conditions was performed.It has been found that the generation of interface states and oxide trapped charges in fluorinated MOSFETs depends strongly on implantation conditions.The action of F in oxides is the conjunction of positive and negative effects.A model by forming Si-F bonds to substitute the other strained bonds which easily become charge traps under irradiation and to relax the bond stress on Si/SiO2 interface is used for experimental explanation.     

COMPETING REACTIONS OF EXISTING Ni SILICIDE AND Ni OR Si INDUCED BY THERMAL ANNEALING AND MeV Si ION BEAM MIXING

The competing reactions between existing Ni silicides surrounded by Si and Ni were investigated by thermal annealing and MeV Si ion beam mixing. With high energy irradiation, the energy deposition at both interfaces, Ni/Ni silicide and Ni silicide/Si, is equal. Two MeV He~- RBS and TEM were used to obtain the reacted layer composition and epitaxial orientation, respectively. Also glancing angle Co K_a. X-ray diffraction was utilized to identify phase formation. The main results indicate that the existing silicides preferentially react with Ni layer, and that there are pronounced differences of Ni silicide phase transition between thermal annealing and MeV Si ion beam mixing, even though the mixing was performed in radiation enhanced diffusion regime. The results can be explained in term of the heat of silicide formation and surface energy change.     

XPS STUDIES OF IRRADIATED HARD AND SOFT Si—SiO_2

The interracial structure of hard and soft oxides grown by dry oxidation on<100> n-type silicon substrates is examined using high resolution mild X-ray photoelectron spectroscopy (XPS) before and after irradiation. Substantial differences in silicon of silica state (B.E. 103.4 eV), silicon of transitional state (B.E. 101.5 eV), surplus oxygen (B.E. 529.6 eV) and negative two-valence oxygen (B.E. 531.4 eV) are observed between the two kinds of samples. The XPS spectra strongly depend on the conditions of irradiation for soft samples, but do not as remarkablely as soft samples for hard samples. The effects of irradiation doses on XPS are greater than that of irradiation bias fields. Some viewpoints of irradiation induced hole electron pair are proposed to explain the results.     

Theoretical Calculation of n ~(59)Co Reaction in Energy Region up to 100 MeV

A set of neutron optical potential parameters for ~(59)Co in energy region of 2～100 MeV was obtained based on concerned experimental data. Various cross sections of n ~(59)Co reactions were calculated and predicted. The calculated results show that the activation products ~(58,57)Co, ~(59)Fe, and ~(56)Mn are main neutron monitor reaction products for n ~(59)Co reaction in energy range up to 100 MeV. ~(54)Mn production reaction can be a promising neutron monitor reaction in the energy region from 30 to 100 MeV.     

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.     

Supersonic Propagation of Heat Waves in Low Density Heavy Material

The propagation of a supersonic heat-wave through copper-doped foam with a density of 50 mg/cm^3 was experimentally investigated. The wave is driven by 140 eV Holhraum radiations generated in a cylindrical gold cavity heated by a 2 kJ, ins laser pulse （0.35 μm）. The delayed breakout time of the radiation waves from the rear side of the foam is measured by a three-chromatic streaked x-ray spectrometer （TCS） consisting of a set of three-imaging pinholes and an array of three transmission gratings coupled with an x-ray streak camera （XSC）. With one shot, simultaneous measurements of the delays of the drive source and the radiation with two different energies （210 eV, 840 eV） through the foam have been made for the first time. The experimental results indicate that the time delays vary with photon energies. The radiation with an energy of 210 eV propagates at a lower velocity. The radiating heat wave propagates with a velocity that is larger than the sound speed. Using TGS, the transmitting spectrum was measured, and then lower limit of the optical depth which is more than 1, was obtained. The experimental data were in agreement with numerical simulations.     

Evaluation of n ~(144,148,154)Sm Reaction Data

Sm is an important nucleus in nuclear science and engineering. The theory data were given by Shen Qingbiao. Spline function was used in the experimental data fit calculation. The corresponding JENDL-3 data are accepted in the energy range of 0.025 eV to 100KeV.     

Performance of Dielectric Barrier Discharge Reactors on Elemental Mercury Oxidation in the Coal-Fired Flue Gas

The oxidation of elemental mercury （Hg~） by dielectric barrier discharge reactors was studied at room temperature, where concentric cylinder discharge reactor （CCDR） and surface discharge plasma reactor （SDPR） were employed. The parameters （e.g. Hg^0 oxidation efficiency, energy constant, energy yield, energy consumption, and O3 concentration） were discussed. From comparison of the two reactors, higher Hg^0 oxidation efficiency and energy constant in the SDPR system were obtained by using lower specific energy density. At the same applied voltage, energy yield in the SDPR system was larger than that in the CCDR system, and energy consumption in the SDPR system was much less. Additionally, more 03 was generated in the SDPR system. The experimental results showed that 98% of Hg^0 oxidation efficiency, 0.6 J·L^-1 of energy constant, 13.7 μg·J^-1 of energy yield, 15.1 eV·molecule^-1 of energy consumption, and 12.7 μg·J^-1 of O3 concentration were achieved in the SDPR system. The study reveals an alternative and economical technology for Hg^0 oxidation in the coal-fired flue gas.     

Effect of Hydrogen Dilution on Growth of Silicon Nanocrystals Embedded in Silicon Nitride Thin Film by Plasma-Enhanced CVD

An investigation was conducted into the effect of hydrogen dilution on the microstructure and optical properties of silicon nanograins embedded in silicon nitride （Si/SiNx） thin film deposited by the helicon wave plasma-enhanced chemical vapour deposition technique. With Ar-diluted SiH4 and N2 as the reactant gas sources in the fabrication of thin film, the film was formed at a high deposition rate. There was a high density of defect at the amorphous silicon （a-Si）/SiNx interface and a relative low optical gap in the film. An addition of hydrogen into the reactant gas reduced the film deposition rate sharply. The silicon nanograins in the SiNx matrix were in a crystalline state, and the density of defects at the silicon nanocrystals （nc-Si）/SiNx interface decreased significantly and the optical gap of the films widened. These results suggested that hydrogen activated by the plasma could not only eliminate in the defects between the interface of silicon nanograins and SiNx matrix, but also helped the nanograins transform from the amorphous into crystalline state. By changing the hydrogen dilution ratio in the reactant gas sources, a tunable band gap from 1.87 eV to 3.32 eV was obtained in the Si/SiNx film.     

Soft switching circuit to improve efficiency of all solid-state Marx modulator for DBDs

For an all solid-state Marx modulator applied in dielectric barrier discharges (DBDs),hard switching results in a very low efficiency.In this paper,a series resonant soft switching circuit,which series an inductance with DBD capacitor,is proposed to reduce the power loss.The power loss of the all circuit status with hard switching was analyzed,and the maximum power loss occurred during discharging at the rising and falling edges.The power loss of the series resonant soft switching circuit was also presented.A comparative analysis of the two circuits determined that the soft switching circuit greatly reduced power loss.The experimental results also demonstrated that the soft switching circuit improved the power transmission efficiency of an all solid-state Marx modulator for DBDs by up to 3 times.     

Measurement of Plasma Parameters of Gliding Arc Driven by the Transverse Magnetic Field

The gliding arc can offer high energy efficiency and selectivity for chemical reactions and has been widely applied in material processing,environmental protection and other industrial areas.But the discharge properties,measurement of plasma parameters and related physical pro-cesses of the gliding arc discharge still need to further studied.In this study,the gliding arc was driven by the transverse magnetic field to produce the non-equilibrium plasma at high pressure.The parameters of the plasma at our observed point were measured by optical methods.The experimental result shows that the electron temperature is about 0.6 eV and the heavy particle temperature is approximately 2987±250 K.     

Formulae for secondary electron yield from insulators and semiconductors

The processes and characteristics of secondary electron emission in insulators and semiconductors were studied, and the formulae for the maximum yield(δ_m) at W_(pOm)≤ 800 eV and the secondary electron yield from insulators and semiconductors δ at the primary incident energy of 2 keV≤ W_(pO) 10 keV(δ_(2-10)) and10 keV ≤ W_(pO)≤100 keV(δ_(10-100)) were deduced. The calculation results were compared with their corresponding experimental data. It is concluded that the deduced formulae can be used to calculate δ_(2-100)at W_(pOm)≤ 800 eV.     

Influence of a Static Magnetic Field on Laser Induced Tungsten Plasma in Air

In this work,laser induced tungsten plasma has been investigated in the absence and presence of 0.6 T static transverse magnetic field at atmospheric pressure in air.The spectroscopic characterization of laser induced tungsten plasma was experimentally studied using space-resolved emission spectroscopy.The atomic emission lines of tungsten showed a significant enhancement in the presence of a magnetic field,while the ionic emission lines of tungsten presented little change.Temporal variation of the optical emission lines of tungsten indicated that the atomic emission time in the presence of a magnetic field was longer than that in the absence of a magnetic field,while no significant changes occurred for the ionic emission time.The spatial resolution of optical emission lines of tungsten demonstrated that the spatial distribution of atoms and ions were separated.The influence of a magnetic field on the spatial distribution of atoms was remarkable,whereas the spatial distribution of ions was little influenced by the magnetic field.The different behaviors between ions and atoms with and without magnetic field in air were related to the various atomic processes especially the electrons and ions recombination process during the plasma expansion and cooling process.     

Studies on microdomain structure in segmented polyether polyurethaneureas by positron annihilation lifetime and small—angle X—ray scattering

The microdomain structure of segmented polyether polyurethaneureas is investigated by means of positron annihilation lifetime spectroscopy,small-angle X-ray scattering and differential scanning calorimetry.The experimental results show that the decrease in the domain volume and free volume results from the increase in the hard segment (polyurethaneurea segment)contents as the number-average molecular weight Mn of the soft segments (polyethylene glycol segments)is the same,and that the increase in domain volume and free volume result from the increase in the Mn of the soft segments when the hard segment content is the same or nearly the same.These results demonstrate that positron annihilation lifetime spectroscopy is a sensitive technique to probe the microdomain structure in polymers.     

Mass attenuation coefficient of olive peat material for absorbing gamma ray energy

The mass attenuation coefficients(μ/ρ)of a natural material,i.e.,olive peat,were measured at photon energies of 0.059,0.356,0.662,1.17,and 1.332 MeV and compared with those of concrete and Pb.The experimental samples were irradiated with ~(214)Am,~(133)Ba,~(137)Cs,and ~(60)Co point sources using a transmission arrangement.The olive peat samples were obtained from different areas in Jordan,namely Mafraq(sample M),Kerak(sample K),Ajloun(sample A),and Irbid(sample I),and photon energies were measured using a NaI(T1)scintillation detector with an energy resolution of 7.6% at 662 keV.The differences in the μ/ρ of olive peat samples and the calculated μ/ρ of concrete were consistently within 0.7% at photon energies of 0.356-1.332 MeV.This finding indicates that olive peat can be used in radiation applications in the field of medical physics.Finally,the half-value layer(HVL)of the experimental samples was measured,and results were compared with those of concrete and Pb.Pb and concrete exhibited minimal HVL values due to their high density,and the HVL of olive peat revealed lower shielding effectiveness than that of concrete.     

Analysis of the Carbon Nano-Structures Formation in Liquid Arcing

Graphite electrodes were used for the direct current （DC） arc discharge in water. And high-resolution transmission electron microscopy （HRTEM） was used to investigate the products. Based on the experimental phenomena and nano-structure products, arc plasma characteristics in water were analyzed theoretically. Two growth regions and relevant growth modes were proposed to interpret the formation mechanisms of nano-structures by arc discharge in water. Furthermore, liquid nitrogen and cross magnetic field was applied to change the arcing state respectively, and new carbon nano-structures were obtained. Their formation mechanisms were also analyzed correspondingly.     

ULTRASOUND INDUCED AND LASER ENHANCED COLD FUSION CHEMISTRY

The standard model of sonoluminescence suggests that the coulomb barrer to deuterium fusion may be overcome by high bubble gas temperatures caused by compression heating if the bubble diameter remains spherical during bubble collapse.However,in the more likely collapse geometry of a pancake shape,the temperature rise in the bubbles is negligible.But the collapsing pancake bubble is fund to significantly increase the frequency of the infrared energy available in the vibrational state of the water molecules at ambient temperature.For a collapse to liquied density,ultraviolet radiation at about 10eV is fund.Although the ultraviolet radiation is of a low intensity,higher intensities may be possible if the bubble collapse is enhanced by visible and infrared lases.Neither hot nor cold fusion is predicted in bubble collapse but the ultraviolet energy at about 10eV developed in the bubble is sufficient to provide the basis for a new field of chemistry called ultrasound induced and laser enhanced cold fusion chemistry.     

Numerical Investigation of Flow Fields in Inductively Coupled Plasma Wind Tunnels

Numerical simulations of 10 kW and 110 kW inductively coupled plasma （ICP） wind tunnels were carried out to study physical properties of the flow inside the ICP torch and vacuum chamber with air as tile working gas. Two-dimensional compressible axisymmetric Navier- Stokes （N-S） equations that took into account 11 species and 49 chemical reactions of air, were solved. A heat source model was used to describe the heating phenomenon instead of solving the electromagnetic equations. In the vacuum chamber, a four-temperature model was coupled with N-S equations. Numerical results for tile 10 kW ICP wind tunnel are presented and discussed in detail as a representative case. It was found that the plasma flow in the vacuum chamber tended to be in local thermoehemical equilibrium. To study the influence of operation conditions on the flow field, simulations were carried out for different chamber pressures and/or input powers. The computational results for the above two ICP wind tunnels were compared with corresponding experimental data. The computational and experimental results agree well, therefore the flow fields of ICP wind tunnels can be clearly understood.     

Estimate of Lifetime of Ion Thruster Optics Based on Particle Simulation

A three-dimensional particle simulation of ion thruster optics with charge-exchange collision was developed in this study. The simulation code was based on tracking ions using the particle-in-cell method, and the Monte Carlo technique was used to model the charge-exchange collision. Simulations were performed for a 20 cm ion thruster optics. The results were compared with the corresponding experimental data from a test of the ion thruster optics for a duration of 800 hours. The Depth-From-Focus （DFF） method was used to measure the erosion depth of the downstream surface of the accelerator grid. The predicted erosion depth of the accelerator grid was consistent reasonably with the corresponding experimental data. The simulation results showed that the accelerator grid would be burned through after 1333 hours.     

Experimental Investigation of Hypersonic Flow and Plasma Aerodynamic Actuation Interaction

For hypersonic flow,it was found that the most efective plasma actuator is derived from an electromagnetic perturbation.An experimental study was performed between hypersonic flow and plasma aerodynamic actuation interaction in a hypersonic shock tunnel,in which a Mach number of 7 was reached.The plasma discharging characteristic was acquired in static flows.In a hypersonic flow,the flow field can afect the plasma discharging characteristics.DC discharging without magnetic force is unstable,and the discharge channel cannot be maintained.When there is a magnetic field,the energy consumption of the plasma source is approximately three to four times larger than that without a magnetic field,and at the same time plasma discharge can also afect the hypersonic flow field.Through schlieren pictures and pressure measurement,it was found that plasma discharging could induce shockwaves and change the total pressure and wall pressure of the flow field.