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RSS2003 Vol. 15, No. 06
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2003,
15.
Abstract:
Parallel pulseforming lines are charged through the high voltage pulsetransformer. Each of these lines includes a magnetic switch acting as pulseforming switch. Adjusting the voltsecond characteristic of the magneticswitch, highvoltage synchronous multipulses are generated. The frequency change is under the control of the thyratron. The whole system is thus characterised with high repetition rate, high synchronous precision, high stabilization and credibility.
Parallel pulseforming lines are charged through the high voltage pulsetransformer. Each of these lines includes a magnetic switch acting as pulseforming switch. Adjusting the voltsecond characteristic of the magneticswitch, highvoltage synchronous multipulses are generated. The frequency change is under the control of the thyratron. The whole system is thus characterised with high repetition rate, high synchronous precision, high stabilization and credibility.
2003,
15.
Abstract:
The design of the first undu1ator UD1 in NSRL is introduced. The design parameters and main technical requirement are given. The quality requirement on undulator magnet field are analysed considering demands of light users as well as that of the electron beam stability. It is given that the first and second integral of the magnet field should be less than 2×１０－４Ｔ·m and 2×１０－４Ｔ·m2 respectively, the phase error should be less than 10°.
The design of the first undu1ator UD1 in NSRL is introduced. The design parameters and main technical requirement are given. The quality requirement on undulator magnet field are analysed considering demands of light users as well as that of the electron beam stability. It is given that the first and second integral of the magnet field should be less than 2×１０－４Ｔ·m and 2×１０－４Ｔ·m2 respectively, the phase error should be less than 10°.
2003,
15.
Abstract:
A high current linear induction accelerator now is being constructed in Institute of Fluid Physics. It consists of 18 blocks, totally 72 induction accelerating cells, and 18 connection cells with ports for beam diagnostic hardware and vacuum pump. The goal of the facility is to obtain high quality, high current pulse electron beams. In order to reduce corkscrew motion caused by energy spread and misalignment of a focusing system some measures to control the transverse motion of beam centroid must be taken. At first magnetic alignment is performed by using pulsedwire technique very carefully, then the tilt errors is corrected by a pair of steering coils, which are located inside each cell, after that based on the alignment data a simple estimate of the beam centroid motion has been done b
A high current linear induction accelerator now is being constructed in Institute of Fluid Physics. It consists of 18 blocks, totally 72 induction accelerating cells, and 18 connection cells with ports for beam diagnostic hardware and vacuum pump. The goal of the facility is to obtain high quality, high current pulse electron beams. In order to reduce corkscrew motion caused by energy spread and misalignment of a focusing system some measures to control the transverse motion of beam centroid must be taken. At first magnetic alignment is performed by using pulsedwire technique very carefully, then the tilt errors is corrected by a pair of steering coils, which are located inside each cell, after that based on the alignment data a simple estimate of the beam centroid motion has been done b
2003,
15.
Abstract:
For most reflective images, scanning of the light field is carried out by a scanning mirror drum, so back scattering light from the reflective mirror, which is illuminated by a laser beam, brings inevitably about a Doppler frequency shift. In this paper, the dynamic echo characteristics of an IR thermal camera, which was illuminated by a laser beam, are analyzed. Selfmodulation of “cat eye effect” is also present. An experiment was designed to measure the Doppler frequency shift of the rotary mirror drum. The analytical results have been proved with a laser radar trace system.
For most reflective images, scanning of the light field is carried out by a scanning mirror drum, so back scattering light from the reflective mirror, which is illuminated by a laser beam, brings inevitably about a Doppler frequency shift. In this paper, the dynamic echo characteristics of an IR thermal camera, which was illuminated by a laser beam, are analyzed. Selfmodulation of “cat eye effect” is also present. An experiment was designed to measure the Doppler frequency shift of the rotary mirror drum. The analytical results have been proved with a laser radar trace system.
2003,
15.
Abstract:
A linear algorithm of simulation of high power laser beam propagation in nonlinear medium is given, based on the BespalovTalanov linearization theory of nonlinear Schrdinger equation. It is faster in 2～3 orders than splitstep Fourier method and more precise while the initial beam distribution is approximately uniform in near field propagation.
A linear algorithm of simulation of high power laser beam propagation in nonlinear medium is given, based on the BespalovTalanov linearization theory of nonlinear Schrdinger equation. It is faster in 2～3 orders than splitstep Fourier method and more precise while the initial beam distribution is approximately uniform in near field propagation.
2003,
15.
Abstract:
The symmetry optical klystron (OK) of NSRL for coherent harmonic generation storagering freeelectron laser (CHGSRFEL) has been reconstructed to asymmetry structure in order to increase the resonant energy of electron beam and generate more powerful coherent harmonic radiation. Each period of the independently adjusted modulator has been extended from 72mm to 92mm, and the number of the periods has changed from 12 to 10. This paper analyzes the relations of the parameters of reconstructed optical klystron, including the resonant energy of electron beam versus the gap of modulator, special parameter of dispersive section versus the gap of dispersive section, and the gap of radiator versus the gap of modulator. It also discusses the factors that influence coherent harmonic radiation and
The symmetry optical klystron (OK) of NSRL for coherent harmonic generation storagering freeelectron laser (CHGSRFEL) has been reconstructed to asymmetry structure in order to increase the resonant energy of electron beam and generate more powerful coherent harmonic radiation. Each period of the independently adjusted modulator has been extended from 72mm to 92mm, and the number of the periods has changed from 12 to 10. This paper analyzes the relations of the parameters of reconstructed optical klystron, including the resonant energy of electron beam versus the gap of modulator, special parameter of dispersive section versus the gap of dispersive section, and the gap of radiator versus the gap of modulator. It also discusses the factors that influence coherent harmonic radiation and
2003,
15.
Abstract:
NCl(a1Δ) /I（2P3/2）System was studied using microwave discharge Cl2/He plasma as Cl atoms source. Strong I (2P1/2) radiation at 1 315nm was obtained. The considerable changes of NCl (a1Δ) and NCl (b1Σ) radiation at 1 077nm and 665nm respectively were observed when a little amount of I2 was injected into the flow of Cl and HN3, namely NCl (a1Δ) radiation at 1 077nm decreased rapidly while NCl(b1Σ) radiation at 665nm increased rapidly due to the reactions NCl(a1Δ)+I(2P3/2)→ NCl(X3Σ)+I(2P1/2) and NCl(a1Δ)+I(2P1/2)→NCl(b1Σ)+I(2P3/2). The intensity dependence of I (2P1/2) radiation at 1 315nm on He, Cl2, HN3 and I2 flow rate was investigated. The results show that the optimum flow rate for gases of He, I２，Cl２ and ＨＮ３ are 1～4, 0.01～0.03, 1 and 1～2mmol/s respectively.
NCl(a1Δ) /I（2P3/2）System was studied using microwave discharge Cl2/He plasma as Cl atoms source. Strong I (2P1/2) radiation at 1 315nm was obtained. The considerable changes of NCl (a1Δ) and NCl (b1Σ) radiation at 1 077nm and 665nm respectively were observed when a little amount of I2 was injected into the flow of Cl and HN3, namely NCl (a1Δ) radiation at 1 077nm decreased rapidly while NCl(b1Σ) radiation at 665nm increased rapidly due to the reactions NCl(a1Δ)+I(2P3/2)→ NCl(X3Σ)+I(2P1/2) and NCl(a1Δ)+I(2P1/2)→NCl(b1Σ)+I(2P3/2). The intensity dependence of I (2P1/2) radiation at 1 315nm on He, Cl2, HN3 and I2 flow rate was investigated. The results show that the optimum flow rate for gases of He, I２，Cl２ and ＨＮ３ are 1～4, 0.01～0.03, 1 and 1～2mmol/s respectively.
2003,
15.
Abstract:
Based on the generalized HuygensFresnel diffraction integral, the closedform propagation expressions for HermitecosineGaussian(HCsG) beams through a paraxial optical ABCD system are derived. The propagation expressions for HermitecoshGaussian(HChG), cosineGaussian(CsG) and HermiteGaussian(HG) beams are obtained readily as special cases of HCsG beams. As application examples, numerical calculations are performed for HCsG beams propagating in free space and focused by a thin lens. The calculated results are shown that HCsG beams can not preserve their shape, while propagating in free space and through a thin lens.
Based on the generalized HuygensFresnel diffraction integral, the closedform propagation expressions for HermitecosineGaussian(HCsG) beams through a paraxial optical ABCD system are derived. The propagation expressions for HermitecoshGaussian(HChG), cosineGaussian(CsG) and HermiteGaussian(HG) beams are obtained readily as special cases of HCsG beams. As application examples, numerical calculations are performed for HCsG beams propagating in free space and focused by a thin lens. The calculated results are shown that HCsG beams can not preserve their shape, while propagating in free space and through a thin lens.
2003,
15.
Abstract:
In process of the arranging experiment data for determining the damage threshold, it is found in some samples that the distribution of the data points of the experiment results deviates obviously from the linear distribution. Under this situation, as the damage threshold is determined from the linear extrapolation of the measured energydensity dependent damage probability based on the ISO11254, another damage threshold of zero probability is obtained by the different nonlinear fit of the experiment data. After making a comparison between these two values and contrasting them with the experiment results, it is obtained from some samples that the damage threshold of zero probability extrapolated by the nonlinear fit is more close to the “real” damage threshold.
In process of the arranging experiment data for determining the damage threshold, it is found in some samples that the distribution of the data points of the experiment results deviates obviously from the linear distribution. Under this situation, as the damage threshold is determined from the linear extrapolation of the measured energydensity dependent damage probability based on the ISO11254, another damage threshold of zero probability is obtained by the different nonlinear fit of the experiment data. After making a comparison between these two values and contrasting them with the experiment results, it is obtained from some samples that the damage threshold of zero probability extrapolated by the nonlinear fit is more close to the “real” damage threshold.
2003,
15.
Abstract:
A measurement system was made with nuclear pore filter which were used to collect atmospheric aerosol particles. We measured the absorption coefficient of light with different pore size filters in 488.0, 514.5 and 632.8nm wavelength. The system has two laser beams: the information one which transfers through glass pipe, and the reference one which transfers directly through atmosphere. In this way the measurement system can well eliminate the effect of all kinds of measurement errors caused by the optical loss, circuit noises and power fluctuation. The system also can decrease the effect of scattering for more precise measurement by partly plating highly reflective membrane. The measurement precision also advances along with increasing time of aerosol collecting. The precision is 9.849×10
A measurement system was made with nuclear pore filter which were used to collect atmospheric aerosol particles. We measured the absorption coefficient of light with different pore size filters in 488.0, 514.5 and 632.8nm wavelength. The system has two laser beams: the information one which transfers through glass pipe, and the reference one which transfers directly through atmosphere. In this way the measurement system can well eliminate the effect of all kinds of measurement errors caused by the optical loss, circuit noises and power fluctuation. The system also can decrease the effect of scattering for more precise measurement by partly plating highly reflective membrane. The measurement precision also advances along with increasing time of aerosol collecting. The precision is 9.849×10
2003,
15.
Abstract:
This article theoretically studies phase matching, parametric bandwidth, gain property of optical parametric chirped pulse amplification of BBO, LBO and KDP. It compares properties of optical parametric chirped pulse amplification between BBO and LBO in detail. The results show that it is better to use BBO in Ti:sappire system with 800nm central wavelength and LBO with 1 053nm central wavelength.
This article theoretically studies phase matching, parametric bandwidth, gain property of optical parametric chirped pulse amplification of BBO, LBO and KDP. It compares properties of optical parametric chirped pulse amplification between BBO and LBO in detail. The results show that it is better to use BBO in Ti:sappire system with 800nm central wavelength and LBO with 1 053nm central wavelength.
2003,
15.
Abstract:
The rate equations to describe the Tidoped sapphire amplifier were given. The temporal and spatial properties of the amplified spontaneous emission and the inversion population density in the amplified medium were studied. It is proved that, the effect of the amplified spontaneous on the gain of amplifier can be controlled by the delay time between the pump pulse and amplified pulse.
The rate equations to describe the Tidoped sapphire amplifier were given. The temporal and spatial properties of the amplified spontaneous emission and the inversion population density in the amplified medium were studied. It is proved that, the effect of the amplified spontaneous on the gain of amplifier can be controlled by the delay time between the pump pulse and amplified pulse.
2003,
15.
Abstract:
Theory analysis were performed for ytterbium doped fiber amplifier(YDFA) on its characteristics of mismatching amplification on chirpedpulse with mid wavelength around 1 053nm. An excellent pulse can be achieved with optimistic input intensity and spectrum width. On the other end, by analyzing the phasemode of YDFA's mismatch amplication, a good result was found. Although the phasemodulate was serious, the phasemodulate during YDFA mismatch amplification affected the quality of pulse after compression weakly.
Theory analysis were performed for ytterbium doped fiber amplifier(YDFA) on its characteristics of mismatching amplification on chirpedpulse with mid wavelength around 1 053nm. An excellent pulse can be achieved with optimistic input intensity and spectrum width. On the other end, by analyzing the phasemode of YDFA's mismatch amplication, a good result was found. Although the phasemodulate was serious, the phasemodulate during YDFA mismatch amplification affected the quality of pulse after compression weakly.
2003,
15.
Abstract:
This paper presents a numerical model of atmospheric optical refractive index structure parameter.A sensitivity analysis indicates that refractive index structure parameter is particularly sensitive to time of the year,the product of soil capacity and volumetric water content,over snow or water, and the state of the cloud cover.The wind speed has almost no effect on refractive index structure parameter．
This paper presents a numerical model of atmospheric optical refractive index structure parameter.A sensitivity analysis indicates that refractive index structure parameter is particularly sensitive to time of the year,the product of soil capacity and volumetric water content,over snow or water, and the state of the cloud cover.The wind speed has almost no effect on refractive index structure parameter．
2003,
15.
Abstract:
A theoretical model for the new type phaseconjugator using combined fiber, which is composed of two fibers with different core diameters connected by an internal taper, is established. By numerical calculation the whole SBS process in combined fiber has been illustrated clearly and its key characters have been discussed. The results show that the combined fiber can greatly decrease SBS threshold and improve reflectivity while behaves a much larger dynamic range. Furthermore, with optimum dimensions, the combined fiber can suppress the power modulation of Stokes wave and show a potentiality to considerably compress laser pulse.
A theoretical model for the new type phaseconjugator using combined fiber, which is composed of two fibers with different core diameters connected by an internal taper, is established. By numerical calculation the whole SBS process in combined fiber has been illustrated clearly and its key characters have been discussed. The results show that the combined fiber can greatly decrease SBS threshold and improve reflectivity while behaves a much larger dynamic range. Furthermore, with optimum dimensions, the combined fiber can suppress the power modulation of Stokes wave and show a potentiality to considerably compress laser pulse.
2003,
15.
Abstract:
The microwave vulnerability effect of IC was presented in this paper. The damage power threshold of IC will decrease with the decrease of microwave frequency or the increase of pulse repetitive frequency, and if the microwave pulse width become larger, the damage power threshold will decrease too. However, there is an inflexion range and the damage power threshold varies little when the pulse width is larger than the inflexion range. The experiment results show that the damage power threshold of IC fit normal distribution, and the variance is very small, so the damage probability fits 0—1 distribution.
The microwave vulnerability effect of IC was presented in this paper. The damage power threshold of IC will decrease with the decrease of microwave frequency or the increase of pulse repetitive frequency, and if the microwave pulse width become larger, the damage power threshold will decrease too. However, there is an inflexion range and the damage power threshold varies little when the pulse width is larger than the inflexion range. The experiment results show that the damage power threshold of IC fit normal distribution, and the variance is very small, so the damage probability fits 0—1 distribution.
2003,
15.
Abstract:
Fully electromagnetic particle-in-cell simulations are performed to study the effects of an external magnetic field on coaxial plasma opening switch (POS). The simulation results show that POS opening performance can be significantly improved only when external longitudinal magnetic field coils are placed at the cathode side, and an additional azimuthal magnetic field is effective whether the central electrode is of positive or negative polarity. Voltage multiplication coefficient K rises with the additional magnetic field increasing till the electron current is completely magnetically insulated during the opening of POS.
Fully electromagnetic particle-in-cell simulations are performed to study the effects of an external magnetic field on coaxial plasma opening switch (POS). The simulation results show that POS opening performance can be significantly improved only when external longitudinal magnetic field coils are placed at the cathode side, and an additional azimuthal magnetic field is effective whether the central electrode is of positive or negative polarity. Voltage multiplication coefficient K rises with the additional magnetic field increasing till the electron current is completely magnetically insulated during the opening of POS.
2003,
15.
Abstract:
In this paper, the effects of the height of channel, the return stroke speed and the permittivity of ground on the return stroke radiation field are discussed based on TL, MTLL, MTLE, TCS and BG model. Assuming a common current wave shape at the channel base, the electromagnetic field have been calculated under different conditions. The calculating results show that the height of channel doesn't affect the field before the current gets to the channel end. The initial peak of electromagnetic field increases with increasing return stroke speed, same as the high frequency component of electromagnetic field at close range. The permittivity of ground affects the initial peak and the wave tilt of fields.
In this paper, the effects of the height of channel, the return stroke speed and the permittivity of ground on the return stroke radiation field are discussed based on TL, MTLL, MTLE, TCS and BG model. Assuming a common current wave shape at the channel base, the electromagnetic field have been calculated under different conditions. The calculating results show that the height of channel doesn't affect the field before the current gets to the channel end. The initial peak of electromagnetic field increases with increasing return stroke speed, same as the high frequency component of electromagnetic field at close range. The permittivity of ground affects the initial peak and the wave tilt of fields.
2003,
15.
Abstract:
The linear dispersion relation of the electromagnetic waves in a plasmapartfilled slowwave structure is analyzed and calculated. Dispersion curves of the TM01 is up shift to 1GHz as the plasma density increases to 8×1011cm-3 with the plasma thickness of 0.2cm. The result is in good agreement with the experimental result observed by X·Zhai. It is found that a series of lowfrequency plasma modes satisfy Floquet theorem in the magnetized plasmapartfilled slowwave structure. These modes can interact with relativistic electron beam and the peakgrowth rates of some modes are as high as that of TM0n modes. Increasing the plasma density, the peakgrowth rate of the plasma mode increases quickly, and becomes greater than that of the TM0n modes. For the plasma density greater than
The linear dispersion relation of the electromagnetic waves in a plasmapartfilled slowwave structure is analyzed and calculated. Dispersion curves of the TM01 is up shift to 1GHz as the plasma density increases to 8×1011cm-3 with the plasma thickness of 0.2cm. The result is in good agreement with the experimental result observed by X·Zhai. It is found that a series of lowfrequency plasma modes satisfy Floquet theorem in the magnetized plasmapartfilled slowwave structure. These modes can interact with relativistic electron beam and the peakgrowth rates of some modes are as high as that of TM0n modes. Increasing the plasma density, the peakgrowth rate of the plasma mode increases quickly, and becomes greater than that of the TM0n modes. For the plasma density greater than
2003,
15.
Abstract:
Electromagnetic pulse (EMP) generated by electrostatic discharge (ESD) spark can severely interfere in normal operation of the electronic systems and even damage them. In this paper, a numerical model of electromagnetic fields generated by ESD spark is presented using FiniteDifference TimeDomain (FDTD) method, in which the influence of electrostatic charge on the electrode over the electric field is taken into account. Electromagnetic fields calculated by this model are compared with those by the analytic method and they make a good agreement with each other. Therefore, this model can be applied to study energy coupling problems between electromagnetic fields generated by ESD spark and electronic systems.
Electromagnetic pulse (EMP) generated by electrostatic discharge (ESD) spark can severely interfere in normal operation of the electronic systems and even damage them. In this paper, a numerical model of electromagnetic fields generated by ESD spark is presented using FiniteDifference TimeDomain (FDTD) method, in which the influence of electrostatic charge on the electrode over the electric field is taken into account. Electromagnetic fields calculated by this model are compared with those by the analytic method and they make a good agreement with each other. Therefore, this model can be applied to study energy coupling problems between electromagnetic fields generated by ESD spark and electronic systems.
2003,
15.
Abstract:
In RF cavity, the motion of electrons is affected by microwave. And at the same time, the electron can generate radiation and has influence on microwave in the cavity. According to Maxwell theory, the RF field in the RF cavity can be expressed by modes of the cavity, and actions are different between microwave of different modes and electron beam. In this paper, the self-consistent equations about such actions are established according to Maxwell theory and Lorentz force on electrons. Based on these equations, the single-gap RF cavity is one-dimensionally studied (including how microwave increases and saturates in the cavity), the curves of microwave field versus time are given for different beam currents. The study shows that nonlinear action is very important and microwave field is only
In RF cavity, the motion of electrons is affected by microwave. And at the same time, the electron can generate radiation and has influence on microwave in the cavity. According to Maxwell theory, the RF field in the RF cavity can be expressed by modes of the cavity, and actions are different between microwave of different modes and electron beam. In this paper, the self-consistent equations about such actions are established according to Maxwell theory and Lorentz force on electrons. Based on these equations, the single-gap RF cavity is one-dimensionally studied (including how microwave increases and saturates in the cavity), the curves of microwave field versus time are given for different beam currents. The study shows that nonlinear action is very important and microwave field is only
2003,
15.
Abstract:
This paper presents the simulation results of beam quality effects on the operation of a vircator with a 2.5 dimension particle in cell(PIC) code. The simulation results show that the front edge of the beam pulse has nearly no effect on the saturated microwave output, while a short steep front edge can accelerate the saturation of virtual cathode oscillation, and that the beam pulse width had better be over 16ns. According to the simulation, the microwave efficiency is decreased to 1.5% from 3.8% in the monoenergetic case when the energy spread of the beam electrons is 5%, and beam quality except the energy spread has almost no effect on microwave frequency.
This paper presents the simulation results of beam quality effects on the operation of a vircator with a 2.5 dimension particle in cell(PIC) code. The simulation results show that the front edge of the beam pulse has nearly no effect on the saturated microwave output, while a short steep front edge can accelerate the saturation of virtual cathode oscillation, and that the beam pulse width had better be over 16ns. According to the simulation, the microwave efficiency is decreased to 1.5% from 3.8% in the monoenergetic case when the energy spread of the beam electrons is 5%, and beam quality except the energy spread has almost no effect on microwave frequency.
2003,
15.
Abstract:
On the basis of the three-beam output of basic frequency from “Shenguang-II” laser facility and beam smoothing technology of lens-array, the shock wave with a better planarity in ranged 650~750μm the target was created after optimum design and rational combination for laser beam. Then the efficiency of output beams from “ShenguangII” laser facility had been raised. And the shock stability experiment with the inclinedplane target indicated that the shock wave steadily propagated in the Al target of thickness of about 28.38~55.82μm and 22.13~35.07μm under the power density of 3.26×1014W/cm2 and 3.11×1014W/cm2 respectively.
On the basis of the three-beam output of basic frequency from “Shenguang-II” laser facility and beam smoothing technology of lens-array, the shock wave with a better planarity in ranged 650~750μm the target was created after optimum design and rational combination for laser beam. Then the efficiency of output beams from “ShenguangII” laser facility had been raised. And the shock stability experiment with the inclinedplane target indicated that the shock wave steadily propagated in the Al target of thickness of about 28.38~55.82μm and 22.13~35.07μm under the power density of 3.26×1014W/cm2 and 3.11×1014W/cm2 respectively.
2003,
15.
Abstract:
This paper reports the results of the measurement of hot electron energy spectrum during the interaction of femtosecond laserplasmas. First, there is a depression of hot electron fluence at the energy of around 40keV. Second, there is a local plateau of electron fluence at energies of 100~350keV, which is produced by the several acceleration mechanisms, and a rapid reduction of electron at energy greater than 350keV. In the range of 1~5.4MeV, the number of hot electrons decays approximately by an exponential function. Fitted with Maxwellian distribution, the temperature of hot electrons is much lager than those from the known temperature scaling, which is due to runup of the energy spectrum at its tail and the selffocusing or channeling of laser.
This paper reports the results of the measurement of hot electron energy spectrum during the interaction of femtosecond laserplasmas. First, there is a depression of hot electron fluence at the energy of around 40keV. Second, there is a local plateau of electron fluence at energies of 100~350keV, which is produced by the several acceleration mechanisms, and a rapid reduction of electron at energy greater than 350keV. In the range of 1~5.4MeV, the number of hot electrons decays approximately by an exponential function. Fitted with Maxwellian distribution, the temperature of hot electrons is much lager than those from the known temperature scaling, which is due to runup of the energy spectrum at its tail and the selffocusing or channeling of laser.
2003,
15.
Abstract:
A calculating function relation about liquid H2 thickness of cryogenic target is proposed using the mass conservation in the target. A general model calculating the liquid H2 thickness in ICF target is established. On the basis of them, some factors effecting the liquid H2 thickness such as temperature and initial gas density has been discussed. The analytic method for the model is also fit for the D-2, T2 or the mixture of the D-T in ICF target．
A calculating function relation about liquid H2 thickness of cryogenic target is proposed using the mass conservation in the target. A general model calculating the liquid H2 thickness in ICF target is established. On the basis of them, some factors effecting the liquid H2 thickness such as temperature and initial gas density has been discussed. The analytic method for the model is also fit for the D-2, T2 or the mixture of the D-T in ICF target．
