2003 Vol. 15, No. 07

Recommend Articles
粒子束及加速器技术
Development of a 40kV/20kW, switchingmode pulse forming network charging power supply
shang lei, lu ye ming, feng de ren, zhao tao, feng guang yao
2003, 15.
Abstract:
A 40kV/20kW switchingmode pulse forming network (PFN) charging power supply was developed by constantcurrent, seriesresonant and softswitching techniques. High pulse to pulse repeatability was achieved even under the condition of high repetition rate and small PFN capacitance. The power supply also featured in high efficiency, small size and the ability of being used in parallel mode. The techniques can be applied to injection/extraction system of circular accelerators, klystron modulators in Linasc and radar transmission. Design of the power supply and PFN charging and discharging experiments are presented in the paper.
Physical model and numerical simulation of intense pulsed electron beam surface modification
qin ying, wu ai-min, zou jian-xin, hao sheng-zhi, liu yue, wang xiao-gang, dong chuang
2003, 15.
Abstract:
A one-dimension temperature and stress model is proposed based on the beam-target interaction process and thermal-elastic theory for the intense pulsed electron beam treatment. The temperature and stress profiles are derived by the numerical simulation. According to the simulation, the melted layer is about 2000nm in depth, the rate of rapid heating and cooling reaches 108~109 K/s, the amplitude of quasi-static thermal stress is about several hundreds MPa, the vibratory frequency of thermal stress wave is about 10-6~108Hz. The simulation explains satisfactorily the observed experimental phenomena as the surface melting depth and the depth distribution of microhardness.
Nonlinear transport of intense beams in dipole magnets—Lie algebraic analysis
l jian qin, li jin hai, li chao long
2003, 15.
Abstract:
Lie algebraic methods are used in the analysis of nonlinear transport of charged particle beams in dipole magnets. Space charge forces are included. The particle distribution used is of KV type. Second order terms of particle rays are obtained, and higher orders could be approached if necessary.
DD neutron relative sensitivity of cerium fluoride scintillation detector
hu meng chun, ye weng ying, zhou dian zhong, wang zhen tong, zhang jian hua, hu qing yuan, yang hong qiong, yang gao zhao
2003, 15.
Abstract:
Two kinds scintillation detectors are composed of cerium fluoride (CeF3) and ST401 with photomultiplier tube respectively, the experimental sample of CeF3 is the newly developed inorganic scintillator in China in recent years, ST401 is a common plastic organic scintillator. The DD neutron relative sensitivity of the two scintillation detectors are measured in DD neutrons source radiation field, which indicate that the DD neutron sensitivity of CeF3 scintillation detector is less than onetenth that of ST401 with same volume.
Time resolved energy spectrum diagnostics for 2MeV injector pulsed electron beam
deng jian jun, chen si fu, li jing, chang li hua, yang guo jun, lin yu zheng
2003, 15.
Abstract:
Energy variation in pulsed electron beam could result in corkscrew motion of the beam centroid in linear induction accelerator, therefore enlarge and distort the spot size of the accelerator. The method using Cerenkov radiation produced by the electrons passing through the quartz to measure the time resolved energy spectrum is described in this paper. The time resolved energy spectrum diagnostics has been carried out for the pulsed intense electron beam of 2MeV injector at Institute of Fluid Physics of CAEP. Comparison of the experimental results between time resolved energy spectra and diode voltage waveforms are given and analysed. The measured energy is about 2.2MeV, the maximum energy variation in 60ns is 4%。
Research of Pre-pulse Gas Switch for Qiangguang I Generator
cong pei-tian, kuai bin, qiu ai-ci, zeng zheng-zhong, liang tian-xue, wang liang-ping, zhang zhong, jia wei, guo ning, chen hong
2003, 15.
Abstract:
The gas switch is one of the commonly employed parts in accelerators. The pre-pulse gas switches in Qiangguang-I is studied in this paper. The parameters of the gas switches are calculated, and the characteristics of switches under constant voltage are obtained through calculation and experiments, on the basis of which the switch gap and pressure are determined to eliminate the pre-pulse voltage to the diode. Both the simulation waveforms and experimental waveforms are shown finally.
Study on the laser triggered multistage and multichannel switch
li hong tao, ding bo nan, xie wei ping, deng jian jun, wang yu juan, qing wei dong, fu zhen, wan bu yong, wang hou ming, gong de sen, ren jing, meng wei tao, ding sheng
2003, 15.
Abstract:
This paper reported the design and experimental results of a 200kV laser triggered multistage and multichannel switch. When a quadruple Nd:YAG laser set was used as a trigger source, it was found that the delay decreased exponentially as the charging voltage, pressure or the energy of laser pulse increased when N2 was filled in gaps. The delay increased as the density of SF6N2 mixtures increased and as the focal length of lens increased for N2, but it is not obvious for SF6N2 mixture. The discharging phenomenon of multichannel was observed.
Radiation energy loss and cooling of onedimensional crystallization beam
luo shi yu, hu xi duo, shao ming zhu, wu mu ying, chen shao wen
2003, 15.
Abstract:
Suppose only the focussing and the Coulomb force act on an ion, where the focussing force is linear and the Coulomb force is nonlinear. When the two forces are balanced, the critical spacing between ions can be obtained. In this paper the radiation energy loss and the cooling of the onedimensional crystallization beam are discussed. The coherent transverse equation of particle motion has been reduced to Duffing equation with the hardspring properties in the frame of Newton mechanics. This nonlinear equation has been solved exactly by a Jacobian elliptical function, and the motion period of a particle has been expressed exactly by the firstkind complete elliptical integral. The energy loss and the beam cooling by the electromagnetic radiation of a charged particle in a storage r
Ionirradiationinduced amorphization of Zr(Cr,Fe)2 precipitate
zu xiao tao, zhang chuan fei, xiang xia, wu ji hong, zhao wen jin, wang lu min
2003, 15.
Abstract:
The 600keV Ne+ ion irradiation and insitu TEM observation were performed in a Zircaloy 4 using the HVEMTandem Facility at 350℃, and the ion flux was 2.5×1012cm-2·s-1. The structural damage upon irradiation was monitored by the selected area electron diffraction patterns (SAED) under insitu TEM observations. The amorphization transformation was determined by the disappearance of all diffraction maxima in the SAED patterns and microstructural contrast. The results show that in situ 600keV Ne irradiation at 350℃, stacking fault contrast starts fading up to 0.2dpa, and disappears basically up to 0.4dpa, and the disorder of Zr(Cr,Fe)2 precipitate happens at the same time. The Zr(Cr,Fe)2 precipitate becomes amorphous at a dose of about 2.7dpa.
高功率激光与光学
Target classification with “cat eye effect”
ge cheng liang, huang zhi wei, ji yun song, li guo hui, zhang wei, fan guo bin, liang zheng
2003, 15.
Abstract:
In an optical system, “cat eye effect” can be modeled as a focus lens system. Based on the model and Fourier transform, when a system has some optoelectrical devices and illuminated by one laser beam, the laser beam will be reflected from the system along incident direction as a result of “cat eye effect”. The experimental proof is made by the detection of laser power backscattered from the optosensitive material, such as CCD. The experiments show that “cat eye effect” surely exists in the optoelectrical detectors. With “cat eye effect”, the target with optoelectrial detectors could be detected and classified. In the experiment, the ratio of the laser power reflected from the CCD detector surface and the input laser power is about 4%. Though the experiments are simple and its d
A flatfield XUV spectrograph with 30~50nm flat region
cheng yuan-li, zhao yong peng, song jian-wei, wang ba ling, wang qi
2003, 15.
Abstract:
A flat-field spectrograph with a toroidal mirror at 747.4 mm incident distance was designed that can provide 30~50nm flat field and better space resolution. XUV spectrum from a hollow cathode gaseous discharge source filled with He gas was measured using this flatfield spectrograph. The spectrograph system can produce a space-resolved spectral images with spectral resolution of 0.001 around 30nm with 0.1mm the incident slit. The spectrograph system will be used to detect the XUV emission from capillary discharge plasma.
Fabrication of broadband antireflective films by sol-gel spincoating process for high power lasers
wei yun, hai-bing, jiang xiao-dong, tang can, ren huan, li ke
2003, 15.
Abstract:
The technique to fabricate a doublelayer broadband antireflective (AR) film by sol-gel spin-coating process for high power lasers was investigated. The double-layer film was composed of a single SiO2 AR coating with reflective index about 13 and silicone coating with reflective index about 1.4. The experimental result showed, when the physical thickness of silicone film and SiO2 AR film were 112nm and 125nm respectively, the doublelayer AR film can be developed with transmission greater than 99% at the waveband range from 430nm to 800nm, which can meet the optical quality of shield glass for the prototype of ShenguangIII facility.
Demonstration of the technique of imaging with circular interference fringes
peng ren-jun, wu jian
2003, 15.
Abstract:
In this paper the frequency analysis is employed to investigate the image reconstruction process using circular interfering fringes. An experiment is used to demonstrate the reconstruction process and the reconstructed image of a twodimension object is reported. The technique of laser interferometric imaging takes advantage of the relative motion between the fringes(formed with laser) and the object to obtain the image information of the object. For the case of the laser interferometric imaging in which the circular fringes is adopted, it is often described with the principle of holography.
Measurement of O2(a1Δ)yield of COIL singlet oxygen generator using Raman spectroscopy
zhao wei-li, duo li-ping, chen fang, fang ben-jie, zhang yue-long, sang feng-ting
2003, 15.
Abstract:
A spontaneous Raman scatting system was used to measure the O2(a1Δ)yield of singlet oxygen generator for chemical oxygen iodine laser. Many common experimental problems, such as fluctuations in laser power, dirty windows, and misalignment, can be ratioed out because of monitoring in the same measurement volume. Present the results from the tests that conducted on 0.1mol/s jettype singlet oxygen generator. The error in the yield measurement is less than 8%.
Detection of NO concentration in flame by planar laser induced fluorescence
guan xiao-wei, liu jin-ru, huang mei-sheng, hu zhi-yun, zhang zhen-rong
2003, 15.
Abstract:
This paper presents the principles and the experiment details of planar laser induced fluorescence(PLIF). With a tunable OPO laser, the fluorescence images of NO were got in a methaneair flame and high energy fuel flame at different time and different pressure. The paper also analyzes the structures of the spectrum and discusses experimental results.
Mass flowrate coefficient in relation to secondary flow of HYLTE nozzle in DF/HF chemical lasers
shi jian hua, yuan sheng fu, hua wei hong, jiang zong fu, wang hong yan
2003, 15.
Abstract:
The secondary mass flowrate of the HYLTE nozzle in DF/HF chemical lasers was numerically and theoretically calculated, the mass flowrate coefficients of D2,H2 and He with 0.01~0.4MPa stagnation pressure and 0.1~0.9mm height of the half throat are obtained. The changerules of mass flowrate coefficient with stagnation pressure and half throat's height were got, the functions deduced from these rules were of satisfactory preciseion. As a result, some suggestions are presented on the design and maintenance of secondary nozzle.
Reflection delay expression of light wave reflected by multilayer dielectric coatings
lan lan, yang li ming, lin xiao dong, qiu fu min, chen jian guo
2003, 15.
Abstract:
Recursion formula of the reflection coefficient of a multilayer dielectric coating has been deduced by employing the equivalent cavity model, based on the principle of multibeam interference. Using this formula, the paper shows that, around the central frequency of the coating, the complex reflection coefficient can be expressed as the product of the reflection coefficient for the central frequency and a phase factor. Further, the expressions for the phase and reflection delays have also been derived.
ICF与激光等离子体
Preparation of polystyrene composite microshells doped with aluminum oxide
cai pei jun, tang yong jian, feng chang gen, zhang lin
2003, 15.
Abstract:
Polystyrene composite shells doped with aluminum oxide used for inertial confinement fusion (ICF) experiments were fabricated with emulsion techniques. Three different phases of solution(W1,O,W2) were adopted for the fabrication process. The W1 phase (water) was mixed with a 3wt% Al2O3PS solution in benzenedichloromethane (O phase ) while stirring. The mixed emulsion (W1/O) was then poured into a 5wt% aqueous PVA solution (W2 phase). Benzene and dichloromethane were evaporated from the resultant emulsion (W1/O/W2), and thus solid Al2O3PS composite shells were formed. Parameters of the typical hollow pellets fit in with the requirement of ICF experiments.
Research status quo and application prospect of capillary plasma jet technique
liu ke fu, xia sheng guo, pan yuan
2003, 15.
Abstract:
Capillary discharge plasma is a new type of high pulsed energy particle source which is recently developed. Plasma jets with high temperature, high density and hypervelocity can be produced by high voltage discharge between two electrodes of a capillary. It can be used for projection of microparticle, acceleration of powder material and ignition and heating of chemical propellant. Such a technique has wide applications in industry, science and national defense. This paper presents the basic theory and characteristics of capillary plasma jets and introduced the research status quo and its applications so that this technology can be paid attention to by people and developed in our country.
Numerical study of Kr gaspuff pinch plasmas
duan yao yong, guo yong hui, wang wen sheng, qiu meng tong, qiu ai ci
2003, 15.
Abstract:
This paper presents a twodimensional threetemperature physical model of Zpinch plasmas and its numerical methods. A twodimensional radiation magnetohydrodynamics code called Zpinch2DDG is developed, which numerically simulates Kr gaspuff plasma implosion based up on the real experimental parameters on the Qiang Guang1 generator. The evolutional pictures of the plasma density and temperature are given, and Xray radiation is analyzed physically. As a result, some universal conclusions about gaspuff implosion are summarized.
高功率微波
Three dimension software simulation for slowwave characteristic and beamwave interaction of coupled cavity circuit
lei wen qiang, yang zhong hai, liao ping
2003, 15.
Abstract:
The computer simulation from cold cavity to hot cavity of Hughes coupled cavity slowwave structure is depicted used by MAFIA. Cold cavity simulation result is compared with theoretical and experimental ones. The average error of dispersion is 0.02% and the average error of interaction impedance is 5%. So the simulation result is more consistent with experiment result than theory result. It may satisfy design precision requirement. Loaded in three dimension particleincell module in cold cavity simulation, the beamwave interaction simulation is done using by MAFIA software. The mechanism of beamwave interaction is qualitatively analyzed by software simulation.
30GHz RF pulse compressor
gu peng-da
2003, 15.
Abstract:
A 30 GHz RF pulse compressor is designed using MSLED-II principle to obtain 150ns long 100MW RF pulse. HHybrid,TE口10TEo01mode converter and other RF components are designed using new principle. There are not any tuning post, capacitive iris, sharp corners in the components designed to avoid sparking under high power level. HFSS code has been extensively used in the RF components design.
Mode distribution and power diagnosis of the high power microwave from vircator with the antenna array
li shao fu, miao te ying, zhang gui rong, yu ai min, gong hai tao
2003, 15.
Abstract:
The principle and method of using antenna array to diagnose the mode distribution, which is used in the experiment of high power microwave radiation of half reflected over mode circular cavity vircator, is introduced. Diagnosis of the modes is very useful to understand the vircator and enhance the output microwave power and the efficiency of the device. The small electric antenna and small magnetic antenna on the surface of circular waveguide are also used to diagnose the modes, which are combined in the antenna array to diagnose the space distribution of the radiation of the open end of over mode circular waveguide. The least square optimization formula is used to fit the mode distribution to the space distribution data. The power distribution of the mix modes of the vircator microwave so
High-altitude electromagnetic pulse environment over the lossy ground
xie yan-zhao, sun bei-yun, zhou hui-, wang zan-ji, wang qun-shu
2003, 15.
Abstract:
The electromagnetic field above ground produced by an incident highaltitude electromagnetic pulse plane wave striking the ground plane was described in this paper in terms of the Fresnel reflection coefficients and the numerical FFT. The pulse reflected from the ground plane always cancel the incident field for the horizortal field component, but the reflected field adds to the incident for the vertical field component. The results of several cases for variations in the observation height, angle of incidence and lossy ground electrical parameters were also presented showing different efield components above the earth.
Prepulse effects on the characteristics of relativistic magnetron
li tian-ming, li jia-yin, yu xiu-yun, ma wen-duo, ge peng
2003, 15.
Abstract:
Based on the origin of prepulse, the prepulse effects on the relativistic magnetorn were analysed. The prepulse effects mainly include three aspects: making the voltage waveform changed, advancing the production of plasma, and enhancing the mode competition. Those effects will finally limit the characteristics of the relativistic magnetron. Linking with the experiments, the relations of those factors were discussed in detail.
Application of timefrequency analysis on UWB scattering signal processing
wang yun fei, wang jing jin, liu guo zhi
2003, 15.
Abstract:
this paper, the basic principle of the timefrequency(TF) analysis, including wavelet transform, is depicted briefly. It's application on UWB scattering signal is introduced in detail also. Through the processing of UWB scattering signal from tested target with the aid of the TF analysis, the signature of the target can be gotten easily so that the detection and discrimination of the target might be improved. In the work, the measurement of scattering signal was made for some simple shaped metal targets which was in air or hidden in some kinds of soil and leaves using picosecond pulse generator (PPG) in the form of bistation configuration, and the experimental data was processed with pseudo Wigner distribution and Mayer wavelet transform. The analytical results prove the superiority