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RSS2000 Vol. 12, No. 03
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2000,
12.
Abstract:
The dynamic dispersion equation of Gyro-TWT is analyzed in this paper. The dependences of the coupling coefficient of beam-wave interaction on the parameters of electron beam are simulated and discussed. The results are helpful to the optimizations of the parameters of electron beam, which could enhance the performance of a Gyro-TWT. The electrons employed in this paper distribute along some circles uniformly, which centers locate at one same circle. The cylindrical waveguide has a uniform section.
The dynamic dispersion equation of Gyro-TWT is analyzed in this paper. The dependences of the coupling coefficient of beam-wave interaction on the parameters of electron beam are simulated and discussed. The results are helpful to the optimizations of the parameters of electron beam, which could enhance the performance of a Gyro-TWT. The electrons employed in this paper distribute along some circles uniformly, which centers locate at one same circle. The cylindrical waveguide has a uniform section.
2000,
12.
Abstract:
The single anode magnetron injection gun which will be employed to 8mm gyrotron of the casing by the permanent magnet experiments is designed. Firstly, analytic equations based on adiabatic theory and angular momentum conservation are used to examine initial design parameters of the electrode shapes. Secondly, the method of the numerical calculation is discussed and selected. Thirdly, the Numerical calculation and optimization is carried out by use of an self-redact electron trajectory code, the space charge effects and the velocity spreads is discussed. Lastly, the optimal parameters with electrode shapes and electronic trajectory was obtained. The single anode magnetron injection gun was employed in the experiments of the gyrotron.
The single anode magnetron injection gun which will be employed to 8mm gyrotron of the casing by the permanent magnet experiments is designed. Firstly, analytic equations based on adiabatic theory and angular momentum conservation are used to examine initial design parameters of the electrode shapes. Secondly, the method of the numerical calculation is discussed and selected. Thirdly, the Numerical calculation and optimization is carried out by use of an self-redact electron trajectory code, the space charge effects and the velocity spreads is discussed. Lastly, the optimal parameters with electrode shapes and electronic trajectory was obtained. The single anode magnetron injection gun was employed in the experiments of the gyrotron.
2000,
12.
Abstract:
By making use of our own program mPND1D, which is used to model the behavior of semiconductor device, we calculated the nonlinear response of the silicon diode stimulated by a high power microwave source. In the code, we considered factors in the set of coupled nonlinear and stiff partial differential equations as many as we can. This set of equations for the electron and hole in a semiconductor of such eight equations as carrier continuity equations. Poison equation heat flow equation and so on.
By making use of our own program mPND1D, which is used to model the behavior of semiconductor device, we calculated the nonlinear response of the silicon diode stimulated by a high power microwave source. In the code, we considered factors in the set of coupled nonlinear and stiff partial differential equations as many as we can. This set of equations for the electron and hole in a semiconductor of such eight equations as carrier continuity equations. Poison equation heat flow equation and so on.
2000,
12.
Abstract:
A diagnostic method of HPM breakdown in waveguide is presented. Experiment results, such as optics-electronics signal of air breakdown, the decline constant of HPM discharge plasma and verification of the conjecture that breakdown point shifts to source. In the mean time, experiment of short pulse HPM breakdown in free space is done. We take the systematic picture of HPM breakdown in free space. Therefore, the directly overall knowing to breakdown characteristic.
A diagnostic method of HPM breakdown in waveguide is presented. Experiment results, such as optics-electronics signal of air breakdown, the decline constant of HPM discharge plasma and verification of the conjecture that breakdown point shifts to source. In the mean time, experiment of short pulse HPM breakdown in free space is done. We take the systematic picture of HPM breakdown in free space. Therefore, the directly overall knowing to breakdown characteristic.
2000,
12.
Abstract:
The character of virtual cathode oscillation (VCO) with e-beam modulated either by external microwave or by self feedback microwave was analyzed and numerically calculated. It was found that by choosing the parameters of the modulating signal correctly, the performance of VCO could be largely improved. The results of theory analysis and numerical calculation agree with those of experiment quite well.
The character of virtual cathode oscillation (VCO) with e-beam modulated either by external microwave or by self feedback microwave was analyzed and numerically calculated. It was found that by choosing the parameters of the modulating signal correctly, the performance of VCO could be largely improved. The results of theory analysis and numerical calculation agree with those of experiment quite well.
2000,
12.
Abstract:
The general properties of natural space radiation environment are summarized, the basic mechanisms of radiation effects are analyzed briefly, In the Monte Carlo Simulation of the radiation effects, the amorphous target material is assumed, the elastic energy loss of incident particle is calculated by binary collision approximation. The inelastic energy loss of project particle for the high energy is calculated by Bethe-Bloch formulation, Lindhard-Scharff formulation is used for low energy and the interpolation formulation was used for the gap between the high and low energy region. The Kinchin-Pease model is used to calculate the secondary damage caused by the displaced lattice atom. Finally the computed results of 100keV Boron incident on silicon are presented and analyzed.
The general properties of natural space radiation environment are summarized, the basic mechanisms of radiation effects are analyzed briefly, In the Monte Carlo Simulation of the radiation effects, the amorphous target material is assumed, the elastic energy loss of incident particle is calculated by binary collision approximation. The inelastic energy loss of project particle for the high energy is calculated by Bethe-Bloch formulation, Lindhard-Scharff formulation is used for low energy and the interpolation formulation was used for the gap between the high and low energy region. The Kinchin-Pease model is used to calculate the secondary damage caused by the displaced lattice atom. Finally the computed results of 100keV Boron incident on silicon are presented and analyzed.
2000,
12.
Abstract:
We estimated the plasma density produced by relativistic electron beam (REB) ionizing neutral gas, using both ionization theory and another method employed often to study energy losses of electron beam transporting through matter in nuclear physics. On experiment, Langmuir probe is employed to measure the plasma density produced by IREB ionizing N2, and the curve which plasma density varies with gas pressure was obtained. The experimental results indicate that plasma density in low pressure (1～15) region is in the order of , which coincides with theoretical estimation, and the method using probe to diagnose plasma produced by IREB ionizing neutral gas was feasible.
We estimated the plasma density produced by relativistic electron beam (REB) ionizing neutral gas, using both ionization theory and another method employed often to study energy losses of electron beam transporting through matter in nuclear physics. On experiment, Langmuir probe is employed to measure the plasma density produced by IREB ionizing N2, and the curve which plasma density varies with gas pressure was obtained. The experimental results indicate that plasma density in low pressure (1～15) region is in the order of , which coincides with theoretical estimation, and the method using probe to diagnose plasma produced by IREB ionizing neutral gas was feasible.
2000,
12.
Abstract:
The detection and reconstruction of wavefront by Lateral Shear Interferometer (LSI) and Hartmann Wavefront Sensor (HWS) have been deduced analogically and simulated numerically. It is shown that the ability of wavefront reconstruction of LSI is better than HWS, for the indirect sampling information of wavefront with LSI is more than HWS. And to increase sampling, LSI is easier than HWS.
The detection and reconstruction of wavefront by Lateral Shear Interferometer (LSI) and Hartmann Wavefront Sensor (HWS) have been deduced analogically and simulated numerically. It is shown that the ability of wavefront reconstruction of LSI is better than HWS, for the indirect sampling information of wavefront with LSI is more than HWS. And to increase sampling, LSI is easier than HWS.
2000,
12.
Abstract:
Mode calculation in unstable resonators with flowing saturable gain using the fast fourier trans-form(FFT) algorithm and thin gain sheet just nearly inside the big mirror. This method is in resonators of small disturbance(f =p / 2), middle magnification(m < 3.0) and lower gain (g0 1%).
Mode calculation in unstable resonators with flowing saturable gain using the fast fourier trans-form(FFT) algorithm and thin gain sheet just nearly inside the big mirror. This method is in resonators of small disturbance(f =p / 2), middle magnification(m < 3.0) and lower gain (g0 1%).
2000,
12.
Abstract:
Model wavefront reconstruction with Zernike circular polynomial and Zernike annular polynomial for annular laser beam are researched. The results are: if wavefront phase of annular laser beam consists of low frequency components only, Zernike circular polynomial can be used to wavefront reconstruction directly ; if wavefront phase of annular laser beam consists of some high spase-frequency components, Zernike annular polynomial will be better.
Model wavefront reconstruction with Zernike circular polynomial and Zernike annular polynomial for annular laser beam are researched. The results are: if wavefront phase of annular laser beam consists of low frequency components only, Zernike circular polynomial can be used to wavefront reconstruction directly ; if wavefront phase of annular laser beam consists of some high spase-frequency components, Zernike annular polynomial will be better.
2000,
12.
Abstract:
In this paper a potential application of free electron laser (FEL) was pointed out. It was also shown in a previous paper[3] that Threshold chemical reaction method (TCR) for laser-based separation of uranium isotopes in molecular forms has advantage of avoiding second excitation over the atomic and other molecular forms. It has larger single-pass separation factor than the atomic and other molecular forms in principle. The requirements for laser adopted in the method can be met by the available technology of FEL driven by electro-static accelerator. It is able to product highly enriched uranium in a small scale of 10kg per year using TCR.
In this paper a potential application of free electron laser (FEL) was pointed out. It was also shown in a previous paper[3] that Threshold chemical reaction method (TCR) for laser-based separation of uranium isotopes in molecular forms has advantage of avoiding second excitation over the atomic and other molecular forms. It has larger single-pass separation factor than the atomic and other molecular forms in principle. The requirements for laser adopted in the method can be met by the available technology of FEL driven by electro-static accelerator. It is able to product highly enriched uranium in a small scale of 10kg per year using TCR.
2000,
12.
Abstract:
It is proved that both amplitude and phase in instantaneous optical processes can be detected from the number density of the excited state populations of coherent carriers when excited with femtosecond laser pulse pairs. Experimental technique of phase spectroscopy is used for investigations of semiconductor GaAs and rare earth solids. Phase spectra of GaAs, crystal Nd:YVO4 and powdered Nd:YAG are obtained. Dephasing time of GaAs exciton is 190fs at 77K and the Nd:YVO4 and Nd:YAG are 300fs at room temperature.
It is proved that both amplitude and phase in instantaneous optical processes can be detected from the number density of the excited state populations of coherent carriers when excited with femtosecond laser pulse pairs. Experimental technique of phase spectroscopy is used for investigations of semiconductor GaAs and rare earth solids. Phase spectra of GaAs, crystal Nd:YVO4 and powdered Nd:YAG are obtained. Dephasing time of GaAs exciton is 190fs at 77K and the Nd:YVO4 and Nd:YAG are 300fs at room temperature.
2000,
12.
Abstract:
Using the Zernike and the Karhunen-Loeve modal reconstruction algorithm, three kinds of reconstruction error of a Hartmann sensor the atmosphere disturbed wavefront was analyzed: the mode coupling error, the mode cutting error and the error causing by measurement noise. The experiment data of a practical Hartmann sensor were analyzed in this paper too. It is showed that the optimal mode number was associated to the signal to noise ratio (SNR), and the Hartmann sensor was suffered from measurement noise severely in the condition of weak turbulence.
Using the Zernike and the Karhunen-Loeve modal reconstruction algorithm, three kinds of reconstruction error of a Hartmann sensor the atmosphere disturbed wavefront was analyzed: the mode coupling error, the mode cutting error and the error causing by measurement noise. The experiment data of a practical Hartmann sensor were analyzed in this paper too. It is showed that the optimal mode number was associated to the signal to noise ratio (SNR), and the Hartmann sensor was suffered from measurement noise severely in the condition of weak turbulence.
2000,
12.
Abstract:
In this paper the drift of beam position on target，together with its error distribution, duo to motion of an optical component caused by structural excitations or thermal excitations in laser bay are reported. The contribution to the change of the beam position on target for each optical component (or parameters of laser system) were analyzed with a ray-trace software, in which the drift of focal spot position about target were computed by adding random perturbation to parameters of optical component (by augmenting a perturbation to the matrix elements of corresponding optical component).
In this paper the drift of beam position on target，together with its error distribution, duo to motion of an optical component caused by structural excitations or thermal excitations in laser bay are reported. The contribution to the change of the beam position on target for each optical component (or parameters of laser system) were analyzed with a ray-trace software, in which the drift of focal spot position about target were computed by adding random perturbation to parameters of optical component (by augmenting a perturbation to the matrix elements of corresponding optical component).
2000,
12.
Abstract:
Quartz crystal oscillation technique was applied to measure the increase of oxide scale on Nd film targets and Auger electron spectroscopy was used to analyze the depth distribution of oxygen and neodymium. Scanning electron microscopy, X-ray diffraction and X-ray photonelectron spectroscopy were used to characterize oxide scale. Results show that the environment where Nd films were stored plays a great role in the oxidation behavior of the Nd films. Water contained in the atmosphere is the key factor for the rapid oxidation of the Nd film. The scale is amorphous and shows steamed bread like surface. The small ratio of the oxide volumn to the metal volummn may be the cause of the Nd inclining to oxidation. The scale is covered by a layer of hydroxide. the thickness of the hydroxide is the
Quartz crystal oscillation technique was applied to measure the increase of oxide scale on Nd film targets and Auger electron spectroscopy was used to analyze the depth distribution of oxygen and neodymium. Scanning electron microscopy, X-ray diffraction and X-ray photonelectron spectroscopy were used to characterize oxide scale. Results show that the environment where Nd films were stored plays a great role in the oxidation behavior of the Nd films. Water contained in the atmosphere is the key factor for the rapid oxidation of the Nd film. The scale is amorphous and shows steamed bread like surface. The small ratio of the oxide volumn to the metal volummn may be the cause of the Nd inclining to oxidation. The scale is covered by a layer of hydroxide. the thickness of the hydroxide is the
2000,
12.
Abstract:
The distribution of temperature increment of CaF2 output window is calculated, which used in 500kW DF laser cavity under convective cooling system. Effects of window’s stress and beam’s phase caused by plane window and spherical window are studied. Related analysis and discussion are given.
The distribution of temperature increment of CaF2 output window is calculated, which used in 500kW DF laser cavity under convective cooling system. Effects of window’s stress and beam’s phase caused by plane window and spherical window are studied. Related analysis and discussion are given.
2000,
12.
Abstract:
Calculating models for flat and spherical planetary fixture were developed. Based on these models, programs were developed to calculate and analyze the film thickness distribution on these type substrates as a function of vaporizing source’s location, emissive characteristic of the source, the vertical height of fixture and the radius of planetary orbit. Representative results were given here.
Calculating models for flat and spherical planetary fixture were developed. Based on these models, programs were developed to calculate and analyze the film thickness distribution on these type substrates as a function of vaporizing source’s location, emissive characteristic of the source, the vertical height of fixture and the radius of planetary orbit. Representative results were given here.
2000,
12.
Abstract:
By simulating wave-front reconstruction with Zernike polynomials, the comparison of detecting performance for the annular beam between two configurations of lens array, which is a key element in Hartmann-Shack wave-front sensor, is presented in this paper. In addition, the matching ability for the annular beam and adaptive capability for the un-uniform intensity are compared. Results show that the annular configuration is better than the square one.
By simulating wave-front reconstruction with Zernike polynomials, the comparison of detecting performance for the annular beam between two configurations of lens array, which is a key element in Hartmann-Shack wave-front sensor, is presented in this paper. In addition, the matching ability for the annular beam and adaptive capability for the un-uniform intensity are compared. Results show that the annular configuration is better than the square one.
2000,
12.
Abstract:
Developing process of filamentation and effect of characteristic parameter in underdense plasma have been studied using numerical simulation method. Production and improvement of two-dimensional cylinder filamentation instability were presented clearly. The results indicate incidence laser intensity and plasma background density are important factors affecting convergent intensity. At the same time, it was showed that different laser wavelength or different electron background density could affect filamentation process. The results are consistent with theory and experiments of alien reports. It can provide reference for restraining filamentation.
Developing process of filamentation and effect of characteristic parameter in underdense plasma have been studied using numerical simulation method. Production and improvement of two-dimensional cylinder filamentation instability were presented clearly. The results indicate incidence laser intensity and plasma background density are important factors affecting convergent intensity. At the same time, it was showed that different laser wavelength or different electron background density could affect filamentation process. The results are consistent with theory and experiments of alien reports. It can provide reference for restraining filamentation.
2000,
12.
Abstract:
The variational problem related to the coupled vector wave equations and boundary conditions of circular dielectric waveguide with arbitrary refractive index profile is solved by using the finite element method (FEM). This method can be used to calculate the mode field for different refractive index profile optical fiber with high precision without any limitation of weakly guiding or Guass Mode field distribution to the dielectric waveguide. The normalized mode field and power proportion inside the core are also studied under different structure parameters of triangular segmented core with step ring optical fiber by this method.
The variational problem related to the coupled vector wave equations and boundary conditions of circular dielectric waveguide with arbitrary refractive index profile is solved by using the finite element method (FEM). This method can be used to calculate the mode field for different refractive index profile optical fiber with high precision without any limitation of weakly guiding or Guass Mode field distribution to the dielectric waveguide. The normalized mode field and power proportion inside the core are also studied under different structure parameters of triangular segmented core with step ring optical fiber by this method.
2000,
12.
Abstract:
The far-field irradiance distribution of a Gaussian beam which is transmitted from telescope with certain center obscure is researched in this paper. First, We derive a representation of irradiance distribution in far field of a Gaussian beam through a obscured telescope without beam's random jitter, and then give a approximation formula of encircled power and spot radius of certain encircled power ratio with and without beam's jitter due to telescope's center obscure. Finally, We researched the joint effects of truncation and obscure on a Gaussian beam's far-field energy distribution.
The far-field irradiance distribution of a Gaussian beam which is transmitted from telescope with certain center obscure is researched in this paper. First, We derive a representation of irradiance distribution in far field of a Gaussian beam through a obscured telescope without beam's random jitter, and then give a approximation formula of encircled power and spot radius of certain encircled power ratio with and without beam's jitter due to telescope's center obscure. Finally, We researched the joint effects of truncation and obscure on a Gaussian beam's far-field energy distribution.
2000,
12.
Abstract:
The compton backscattering experiment is put forward to produce hard X rays of high-brightness and polarization for making up the shortcoming of no hard X-ray source in NSRL. And the hard X rays wevelength will be adjusted contiunally by tune the wavelength of FEL. The parameters of FIRFEL and the project of the compton backscattering experiment are present for the storage ring of NSRL, and the theorectical results are given also.
The compton backscattering experiment is put forward to produce hard X rays of high-brightness and polarization for making up the shortcoming of no hard X-ray source in NSRL. And the hard X rays wevelength will be adjusted contiunally by tune the wavelength of FEL. The parameters of FIRFEL and the project of the compton backscattering experiment are present for the storage ring of NSRL, and the theorectical results are given also.
2000,
12.
Abstract:
The surface of K9 glass substrate (with size 90mm×60mm×10mm) was polished by bowl-feed polish. The super smooth surface with roughness less than 1nm and reflective wavefront l /20(p-v) (l =632.8nm ) was got. The high reflective thin film, whose reflectivity is more than 99.5% at wavelength 1054nm for incidence angle 45°, and whose laser induced damage threshold is 26J/cm2 (1054nm, 1ns), was coated on this super smooth surface by electron beam evaporation deposition in the APS1504 coating machine. After alternately coating HfO2 and SiO2 multilayer on the surface, this mirror’s reflective wavefront is l /10(p-v) (l =632.8nm ). The high quality pick-off mirror whose specification is agreement with the designed specification of that type of mirror for the SHEN GUANG Ⅲ was got.
The surface of K9 glass substrate (with size 90mm×60mm×10mm) was polished by bowl-feed polish. The super smooth surface with roughness less than 1nm and reflective wavefront l /20(p-v) (l =632.8nm ) was got. The high reflective thin film, whose reflectivity is more than 99.5% at wavelength 1054nm for incidence angle 45°, and whose laser induced damage threshold is 26J/cm2 (1054nm, 1ns), was coated on this super smooth surface by electron beam evaporation deposition in the APS1504 coating machine. After alternately coating HfO2 and SiO2 multilayer on the surface, this mirror’s reflective wavefront is l /10(p-v) (l =632.8nm ). The high quality pick-off mirror whose specification is agreement with the designed specification of that type of mirror for the SHEN GUANG Ⅲ was got.
2000,
12.
Abstract:
The beam current, energy and brightness of 2MeV injector for 20MeV LIA have been up to 3kA, 2MeV and 108A/(m-rad)2 respectively after the debugging experiment has been lasting for more than one year. A two-dimensional model was used to simulate the processes of electron emission and beam transportation. The calculated results, compared with the experimental results, were analyzed.
The beam current, energy and brightness of 2MeV injector for 20MeV LIA have been up to 3kA, 2MeV and 108A/(m-rad)2 respectively after the debugging experiment has been lasting for more than one year. A two-dimensional model was used to simulate the processes of electron emission and beam transportation. The calculated results, compared with the experimental results, were analyzed.
2000,
12.
Abstract:
The 2-D effect and the initial energy influence of emitting electrons on space-charge-limiting current in diode are studied by PIC simulation and theoretical analysis. The space charge limited current in diode is obtained when the electrons is emitted from cathode with a initial energy. The analytic result is in good agreement with PIC simulation. Meanwhile, the 2-D effect of diode is also studied by PIC simulation, and the 2-D modified factor is obtained, which can be used in the designing and analyzing the experimental data of intense current electron beam diode.
The 2-D effect and the initial energy influence of emitting electrons on space-charge-limiting current in diode are studied by PIC simulation and theoretical analysis. The space charge limited current in diode is obtained when the electrons is emitted from cathode with a initial energy. The analytic result is in good agreement with PIC simulation. Meanwhile, the 2-D effect of diode is also studied by PIC simulation, and the 2-D modified factor is obtained, which can be used in the designing and analyzing the experimental data of intense current electron beam diode.
2000,
12.
Abstract:
This paper describes the structure and principle of RFKO system. Based on the transverse oscillations and timing structure of bunch pulse that are characteristics in storage ring, it excites the beam to produce the coherent oscillations and then,the electrons of some bunches are destroyed，resulting in a partial filling and uniform filling in storage ring. Also,the experimental results of the system are presented.
This paper describes the structure and principle of RFKO system. Based on the transverse oscillations and timing structure of bunch pulse that are characteristics in storage ring, it excites the beam to produce the coherent oscillations and then,the electrons of some bunches are destroyed，resulting in a partial filling and uniform filling in storage ring. Also,the experimental results of the system are presented.
2000,
12.
Abstract:
A hydrodynamics model was used in this paper to study the effects of the electron emission on the steady-state sheaths, which includes the emitted electron-neutral atom collisions and the ion-neutral atom collisions. Numerical results show that the initial emitted electron bean-current density and the neutral gas density are two important physics quantities affecting the sheath parameters, such as the ion density, ion current density, and the sheath electric field.
A hydrodynamics model was used in this paper to study the effects of the electron emission on the steady-state sheaths, which includes the emitted electron-neutral atom collisions and the ion-neutral atom collisions. Numerical results show that the initial emitted electron bean-current density and the neutral gas density are two important physics quantities affecting the sheath parameters, such as the ion density, ion current density, and the sheath electric field.
2000,
12.
Abstract:
The structure of a miniature pulsed ion beam accelerator with the pinch-reflex ion beam diode is described. The diode can steadily work at the voltage of 200kV,and the ion beam current of 1.5kA、average ion beam current density of 110A/cm2 with a pulse width of about 20ns is obtained.
The structure of a miniature pulsed ion beam accelerator with the pinch-reflex ion beam diode is described. The diode can steadily work at the voltage of 200kV,and the ion beam current of 1.5kA、average ion beam current density of 110A/cm2 with a pulse width of about 20ns is obtained.
2000,
12.
Abstract:
RF photoinjector is one kind of high-brightness electron beam sources. Now the better experimental results have been made on CAEP photoinjecter. 70A electron beam of 2MeV in energy is achieved ,10ps micropulse width of 81.25MHz repetition and 2.5us macropulse width of 3Hz repetition. The system works stable, and is made of the driving laser ,the RF cavity for the photoinjecter, the vacuum chamber for Cs2Te photocathode fabrication ,high power microwave system , the measurements, and etc. The driving laser is very important in the system, the output of the driving laser can reach 1uJ/micropulse at the fourth harmonics, and the timing jitter is below 2ps.
RF photoinjector is one kind of high-brightness electron beam sources. Now the better experimental results have been made on CAEP photoinjecter. 70A electron beam of 2MeV in energy is achieved ,10ps micropulse width of 81.25MHz repetition and 2.5us macropulse width of 3Hz repetition. The system works stable, and is made of the driving laser ,the RF cavity for the photoinjecter, the vacuum chamber for Cs2Te photocathode fabrication ,high power microwave system , the measurements, and etc. The driving laser is very important in the system, the output of the driving laser can reach 1uJ/micropulse at the fourth harmonics, and the timing jitter is below 2ps.
2000,
12.
Abstract:
High-quality polystyrene hollow microshells made by emulsion technique were important mandrel of multilayer plastic targets used for ICF experiments.But the polystyrene microshells made by emulsion technique typically appeared with much vacuoles and fabrication of large diameter microshells was very dificult.In this paper,the two problems were discussed in detail.
High-quality polystyrene hollow microshells made by emulsion technique were important mandrel of multilayer plastic targets used for ICF experiments.But the polystyrene microshells made by emulsion technique typically appeared with much vacuoles and fabrication of large diameter microshells was very dificult.In this paper,the two problems were discussed in detail.
2000,
12.
Abstract:
A hydrodynamics model was used in this paper to study the effects of the electron emission on the steady-state sheaths, which includes the emitted electron-neutral atom collisions and the ion-neutral atom collisions. Numerical results show that the initial emitted electron bean-current density and the neutral gas density are two important physics quantities affecting the sheath parameters, such as the ion density, ion current density, and the sheath electric field.
A hydrodynamics model was used in this paper to study the effects of the electron emission on the steady-state sheaths, which includes the emitted electron-neutral atom collisions and the ion-neutral atom collisions. Numerical results show that the initial emitted electron bean-current density and the neutral gas density are two important physics quantities affecting the sheath parameters, such as the ion density, ion current density, and the sheath electric field.
2000,
12.
Abstract:
Making use of a Fabry-Perot interferometer driven by a piezoelectric crystal and selecting the suitable separation of plates, the ion temperature is defined by measuring the superimposed profile of the spectral line pair of the same ionized state ions in tokamak. The advantage of this method is to higher spectral resolution and wider spectral range selectment.
Making use of a Fabry-Perot interferometer driven by a piezoelectric crystal and selecting the suitable separation of plates, the ion temperature is defined by measuring the superimposed profile of the spectral line pair of the same ionized state ions in tokamak. The advantage of this method is to higher spectral resolution and wider spectral range selectment.
