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RSS1996 Vol. 08, No. 02
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1996,
08.
Abstract:
Experiments studing temporal –spatial distribution of radiation in Hohlraum are reported. Two laser beams with wavelength 1.053m m irradiated from two ends of a cylindrical target are used. Three sub –keV X ray energy spectrometers have measured the radiation in Hohlraum for different direction through diagnostic pinhole or laser entrance holes. Finally, the temporal –spatial distribution of the radiation temperature in Hohlraum is given.
Experiments studing temporal –spatial distribution of radiation in Hohlraum are reported. Two laser beams with wavelength 1.053m m irradiated from two ends of a cylindrical target are used. Three sub –keV X ray energy spectrometers have measured the radiation in Hohlraum for different direction through diagnostic pinhole or laser entrance holes. Finally, the temporal –spatial distribution of the radiation temperature in Hohlraum is given.
1996,
08.
Abstract:
The contribution from the geometrical factors to the radiation nonuniformity in the case of an open-end cylindrical hohlraum is discussed. The analysis is facilitated by using temperature profile of the cylindrical hohlraum heated by the two ring sources, the temperature profile of a Tsakiris’Style. The temperature profile is separated from the geometrical factors in the case of vacuum cylinder and small target ball. It is demonstrated how the geometrical factors influence the irradiation nonuniformity with lapse of time. The misalignment and energy imbalance produces odd order rms variation. It is also found that those locations of X ray converters, which have minimum value of rms variation, move toward the edge of cylinder with lapse of time. This suggests that the expansion of wall pla
The contribution from the geometrical factors to the radiation nonuniformity in the case of an open-end cylindrical hohlraum is discussed. The analysis is facilitated by using temperature profile of the cylindrical hohlraum heated by the two ring sources, the temperature profile of a Tsakiris’Style. The temperature profile is separated from the geometrical factors in the case of vacuum cylinder and small target ball. It is demonstrated how the geometrical factors influence the irradiation nonuniformity with lapse of time. The misalignment and energy imbalance produces odd order rms variation. It is also found that those locations of X ray converters, which have minimum value of rms variation, move toward the edge of cylinder with lapse of time. This suggests that the expansion of wall pla
1996,
08.
Abstract:
A novel mechanism generating superradiance harmonics is found in this paper. In this superradiance harmonics, the temporal width of harmonics is extremely short, the ratio of high harmonic fundamental wave is much higher than the known superradiance harmonics.
A novel mechanism generating superradiance harmonics is found in this paper. In this superradiance harmonics, the temporal width of harmonics is extremely short, the ratio of high harmonic fundamental wave is much higher than the known superradiance harmonics.
1996,
08.
Abstract:
A model of T.A.Mehlhorn describes the deposition of energy by Li ion traversing Au material and a ion traversing DT material. Range for ion is shorten with temperature of plasma, and fitting formula is given for range.
A model of T.A.Mehlhorn describes the deposition of energy by Li ion traversing Au material and a ion traversing DT material. Range for ion is shorten with temperature of plasma, and fitting formula is given for range.
1996,
08.
Abstract:
The thermonuclear fuel is mixed with the material from the shell near the fuel in the process of radiation driven implosion. The main results in 1-D numerical simulation have been given and the neutron yield is reduced dramatically by the mixing, which have been analyzed in the paper.
The thermonuclear fuel is mixed with the material from the shell near the fuel in the process of radiation driven implosion. The main results in 1-D numerical simulation have been given and the neutron yield is reduced dramatically by the mixing, which have been analyzed in the paper.
1996,
08.
Abstract:
In this paper the Conde –Bekefi experiment is analyzed by the three –dimensional nonlinear simulations. When a small injection angle of electron beam is introduced, which is similar to the pinch angle in a cyclotron autoresonance maser, the simulation results are in good agreement with the experiment values. This indicates a novel interaction mechanism of FEL with a reversed guide magnetic field.
In this paper the Conde –Bekefi experiment is analyzed by the three –dimensional nonlinear simulations. When a small injection angle of electron beam is introduced, which is similar to the pinch angle in a cyclotron autoresonance maser, the simulation results are in good agreement with the experiment values. This indicates a novel interaction mechanism of FEL with a reversed guide magnetic field.
1996,
08.
Abstract:
This paper presents our research work on the pulsed taut – wire measurement of the magnetic alignment of the high current induction – cell. A fine taut – wire carrying a pulse current was put in the solenoid magnet, and observing the Lorentz force on the wire. If the magnetic axis is an offset or a tilt of the mechanical axis of the solenoid, the wave pattern produced by these errors are different from that produced by the correct one. In our experiments we changed the current pulse amplitude from 0.3A to 3.8A and its width from 300m s to 1.5ms, the length of the solenoid is 40cm, the centering error of the wire is ± 0.05mm. The tilt, the offset and their direction can be distinguished from the waveform. The experimental sensitivity of tilt we estimated is 1mard.Lastly to differentiate
This paper presents our research work on the pulsed taut – wire measurement of the magnetic alignment of the high current induction – cell. A fine taut – wire carrying a pulse current was put in the solenoid magnet, and observing the Lorentz force on the wire. If the magnetic axis is an offset or a tilt of the mechanical axis of the solenoid, the wave pattern produced by these errors are different from that produced by the correct one. In our experiments we changed the current pulse amplitude from 0.3A to 3.8A and its width from 300m s to 1.5ms, the length of the solenoid is 40cm, the centering error of the wire is ± 0.05mm. The tilt, the offset and their direction can be distinguished from the waveform. The experimental sensitivity of tilt we estimated is 1mard.Lastly to differentiate
1996,
08.
Abstract:
This paper introduced the design and tunning of the two kinds of the buncher of the L-band high current injector China Institute of Atomic Energy. Characteristic of the few cavities buncher will be shown and the effect of the two modes of the buncher in high current injector will be given.
This paper introduced the design and tunning of the two kinds of the buncher of the L-band high current injector China Institute of Atomic Energy. Characteristic of the few cavities buncher will be shown and the effect of the two modes of the buncher in high current injector will be given.
1996,
08.
Abstract:
The H –mode has been achieved on HT – 6M Tokamak during Edge Ohmic Heating experiment. The changes of Ha , O II and C III during H –mode, L-H and H-L transition have been studied. The influences of the edge condition, the recycling of particle and impurity on H –mode, L-H and H-L transition have been discussed.
The H –mode has been achieved on HT – 6M Tokamak during Edge Ohmic Heating experiment. The changes of Ha , O II and C III during H –mode, L-H and H-L transition have been studied. The influences of the edge condition, the recycling of particle and impurity on H –mode, L-H and H-L transition have been discussed.
1996,
08.
Abstract:
In this paper, approximate expressions of electron density, electron temperature, fractional population of bare nuclei, escape probability of 2 – 1 transition and gain for 3d5/2 – 2p3/2 transition in H –like C ions in expanding plasma from a laser – irradiated carbon fibre are obtained.
In this paper, approximate expressions of electron density, electron temperature, fractional population of bare nuclei, escape probability of 2 – 1 transition and gain for 3d5/2 – 2p3/2 transition in H –like C ions in expanding plasma from a laser – irradiated carbon fibre are obtained.
1996,
08.
Abstract:
This paper presents voltage pulse and electron beam current measurement on the 10MeV LIA. The 10MeV LIA consists of an 1MV injector of 4 accelerating cavities and a post accelerator of 28 cavities. It’s electron beam transport line is more than 20m long. The cavity voltage pulses are measured with capacitive voltage probes and resistive voltage dividers. The voltage pulse of the injector and the post accelerator are measured by summing passively the signals from the capacitive voltage probes at the injector and the post accelerator respectively and then integrating them with RC integrators respectively. The electron beam currents along the accelerator are measured with resistance ring. By monitoring the image current on the inner pope wall, the beam intensity and position are obtained.
This paper presents voltage pulse and electron beam current measurement on the 10MeV LIA. The 10MeV LIA consists of an 1MV injector of 4 accelerating cavities and a post accelerator of 28 cavities. It’s electron beam transport line is more than 20m long. The cavity voltage pulses are measured with capacitive voltage probes and resistive voltage dividers. The voltage pulse of the injector and the post accelerator are measured by summing passively the signals from the capacitive voltage probes at the injector and the post accelerator respectively and then integrating them with RC integrators respectively. The electron beam currents along the accelerator are measured with resistance ring. By monitoring the image current on the inner pope wall, the beam intensity and position are obtained.
1996,
08.
Abstract:
The measurement of energy spectra of ion beams from the gas – puff Z – pinch plasma device has been carried out in this study by employing the compact Thomson ion energy analyzer developed recently by us. Clear parabolic tracks of Ar+ , Ar2+, Ar3+ ions on CR-39 plastics and energy spectra of these ions have been obtained. The results show that the maximum ion energy is about 1MeV, ion energy spectrum distributions are expressed approximately by dN / dT /dw T-2.
The measurement of energy spectra of ion beams from the gas – puff Z – pinch plasma device has been carried out in this study by employing the compact Thomson ion energy analyzer developed recently by us. Clear parabolic tracks of Ar+ , Ar2+, Ar3+ ions on CR-39 plastics and energy spectra of these ions have been obtained. The results show that the maximum ion energy is about 1MeV, ion energy spectrum distributions are expressed approximately by dN / dT /dw T-2.
1996,
08.
Abstract:
On the Xingguang II laser facilities the soft X ray spectra of a laser –produced plasma of highly ionized 74W in the wavelength range 0.36 ~ 0.52nm were investigated with a plane crystal spectrograph. Four 3dj – nfj (n =5,6) resonance lines in Ni – like ions, as well as sixteen broad, characteristic, pseudo – continuous transition bands in Cu –, Zn –, Ga – and Ge –like ions, were measured and identified accurately. The wavelength precision is ± 0.0005nm. The relativistic Spin – Orbit – Split Arrays (SOSA) model, a particular case of Unresolved Transition Arrays (UTA), and the Xa method support this analysis: The succinct formulas of the mean wavelength vs the ionized stage were achieved first. The data of the experiment and the calculation have important uses for plasma diagnost
On the Xingguang II laser facilities the soft X ray spectra of a laser –produced plasma of highly ionized 74W in the wavelength range 0.36 ~ 0.52nm were investigated with a plane crystal spectrograph. Four 3dj – nfj (n =5,6) resonance lines in Ni – like ions, as well as sixteen broad, characteristic, pseudo – continuous transition bands in Cu –, Zn –, Ga – and Ge –like ions, were measured and identified accurately. The wavelength precision is ± 0.0005nm. The relativistic Spin – Orbit – Split Arrays (SOSA) model, a particular case of Unresolved Transition Arrays (UTA), and the Xa method support this analysis: The succinct formulas of the mean wavelength vs the ionized stage were achieved first. The data of the experiment and the calculation have important uses for plasma diagnost
1996,
08.
Abstract:
Characteristics of a 10.4MeV, 2.4kA intense electron beam from the 10MeV linear induction accelerator focused by solenoid lenses are studied. The experimental magnetic region is acquired through resolving the five –order radial electric rajectory equation, Limits to minimum spot size, imposing by the space –charge effect, emittance and corkscrew motion of electron beams, and the spherical and chromatic aberrations of the lens are investigated by means of an analytical method. Experimentally, a spot diameter of less than or equal to 6mm is obtained. The experimental results are in agreement with the theory computations.
Characteristics of a 10.4MeV, 2.4kA intense electron beam from the 10MeV linear induction accelerator focused by solenoid lenses are studied. The experimental magnetic region is acquired through resolving the five –order radial electric rajectory equation, Limits to minimum spot size, imposing by the space –charge effect, emittance and corkscrew motion of electron beams, and the spherical and chromatic aberrations of the lens are investigated by means of an analytical method. Experimentally, a spot diameter of less than or equal to 6mm is obtained. The experimental results are in agreement with the theory computations.
1996,
08.
Abstract:
The theoretical formulas and calculated resulted of transport of IREB under a converging magnetic guide field is given in this paper. The results is: (1) beam energy transmitted fraction through the magnetic field lens decrease as magnetic mirror rate increase, (2) beam energy transmitted fraction through the magnetic field lens increase as the magnetic flux density at the cathode, (3) there is a up limit on the beam fluence for a certain system.
The theoretical formulas and calculated resulted of transport of IREB under a converging magnetic guide field is given in this paper. The results is: (1) beam energy transmitted fraction through the magnetic field lens decrease as magnetic mirror rate increase, (2) beam energy transmitted fraction through the magnetic field lens increase as the magnetic flux density at the cathode, (3) there is a up limit on the beam fluence for a certain system.
1996,
08.
Abstract:
In this paper, the theoretical atomic energy level values for configurations 4s2, 4s4p, 4s4d, 4s5s of zinc –like isoelectronic sequence ions from Rh X VI to In XX are calculated with HXR method in Cowan’s computer code. By analysing variation of the differences D E between theoretical and experimental energy level values with Zc (Zc=Z–N+1)along the isoelectronic sequences, we put forward a new fit formula. Using this formula and the FORTRAN programe designed by us, we have made a systematic fit calculation for the energy level values of configuration mentioned above. Some unknown energy levels belonging to the ions (RhXVI –In XX)are predicted by interpolate and extrapolate. Also, the 4s2 –4s4p, 4s4p –4s4d transition wavelengths and the corresponding HXR calculating oscillator strengt
In this paper, the theoretical atomic energy level values for configurations 4s2, 4s4p, 4s4d, 4s5s of zinc –like isoelectronic sequence ions from Rh X VI to In XX are calculated with HXR method in Cowan’s computer code. By analysing variation of the differences D E between theoretical and experimental energy level values with Zc (Zc=Z–N+1)along the isoelectronic sequences, we put forward a new fit formula. Using this formula and the FORTRAN programe designed by us, we have made a systematic fit calculation for the energy level values of configuration mentioned above. Some unknown energy levels belonging to the ions (RhXVI –In XX)are predicted by interpolate and extrapolate. Also, the 4s2 –4s4p, 4s4p –4s4d transition wavelengths and the corresponding HXR calculating oscillator strengt
1996,
08.
Abstract:
A method of relative calibration for “Shanghai” soft X ray film, using transmission grating on synchrotron radiation source, is introduced. Characteristics of the film have been studied briefly. Dependence of optical density on relative exposure have been obtained at photon energy of 276eV and 930eV, respectively. The results have been utilized to calibrate diffraction efficiency of transmission grating.
A method of relative calibration for “Shanghai” soft X ray film, using transmission grating on synchrotron radiation source, is introduced. Characteristics of the film have been studied briefly. Dependence of optical density on relative exposure have been obtained at photon energy of 276eV and 930eV, respectively. The results have been utilized to calibrate diffraction efficiency of transmission grating.
1996,
08.
Abstract:
A 5kW supersonic chemical oxygen-iodine laser (COIL) has been constructed. A rotating mesh type singlet –delta oxygen generator (SOG) is used that appears to be simpler, lighter in weight and more efficient than the rotating disk SOG. An output power of 1kW from this supersonic COIL has been achieved by using the rotating mesh SOG at a Cl2 flow rate of 150mmol/s. Theoretical modeling of supersonic COIL based on a simplified premixed model is given.
A 5kW supersonic chemical oxygen-iodine laser (COIL) has been constructed. A rotating mesh type singlet –delta oxygen generator (SOG) is used that appears to be simpler, lighter in weight and more efficient than the rotating disk SOG. An output power of 1kW from this supersonic COIL has been achieved by using the rotating mesh SOG at a Cl2 flow rate of 150mmol/s. Theoretical modeling of supersonic COIL based on a simplified premixed model is given.
1996,
08.
Abstract:
The various recombination processes in Na –like Cu laser –produced plasma are studied. The lower temperature three –body recombination pumping scheme of Na –like Cu soft X ray laser is given in theory.
The various recombination processes in Na –like Cu laser –produced plasma are studied. The lower temperature three –body recombination pumping scheme of Na –like Cu soft X ray laser is given in theory.
1996,
08.
Abstract:
We studied fully and systematically the scaling laws of various abnormal absorptions and property of hot electrons for 1.053m m laser –irradiated hohlraum targets, which were observed with various energy calorimeters and spectrometers at the “Shen Guang –I” facility, from 1990 to 1994. Spectral characteristics, energy of various abnormal absorptions, the hard X ray spectrum are obtained in hohlraum targets. The relation of spectrum and energy of SRS, temperature and energy of hot electron versus laser parameters and targets type are given. Hot electrons and SRS can be reduced obviously for short laser wavelength.
We studied fully and systematically the scaling laws of various abnormal absorptions and property of hot electrons for 1.053m m laser –irradiated hohlraum targets, which were observed with various energy calorimeters and spectrometers at the “Shen Guang –I” facility, from 1990 to 1994. Spectral characteristics, energy of various abnormal absorptions, the hard X ray spectrum are obtained in hohlraum targets. The relation of spectrum and energy of SRS, temperature and energy of hot electron versus laser parameters and targets type are given. Hot electrons and SRS can be reduced obviously for short laser wavelength.
1996,
08.
Abstract:
In this paper, some design features of ECR2 for heavy particle accelerator of Lanzhou are described. The experiment results of the source on a test bench are given. When ECR2 works as the external source of the accelerator, a unusual operation regime is used. Discussions on this regime are presented as well.
In this paper, some design features of ECR2 for heavy particle accelerator of Lanzhou are described. The experiment results of the source on a test bench are given. When ECR2 works as the external source of the accelerator, a unusual operation regime is used. Discussions on this regime are presented as well.
1996,
08.
Abstract:
Two types of bifilar winding on the secondary of a high – power pulse transformer are disussed. Because of some voltage nonequilibrium between two windings and load asymmetrical disposition for the windings the pulse energy will intrude into the cathode heater. The factors which affect the pulse heating energy are the load disposition, the HV pulse equilibrium level between two windings, the pulse width and amplitude, the value of equilibrium capacitor, the equivalent heater resistance, and pulse transformer parameters etc. of which the main factor is the load disposition. The quantitative results show that load symmetrical disposition has a notable advantage and the pulse heating energy after a pulse is much greater than during the pulse.
Two types of bifilar winding on the secondary of a high – power pulse transformer are disussed. Because of some voltage nonequilibrium between two windings and load asymmetrical disposition for the windings the pulse energy will intrude into the cathode heater. The factors which affect the pulse heating energy are the load disposition, the HV pulse equilibrium level between two windings, the pulse width and amplitude, the value of equilibrium capacitor, the equivalent heater resistance, and pulse transformer parameters etc. of which the main factor is the load disposition. The quantitative results show that load symmetrical disposition has a notable advantage and the pulse heating energy after a pulse is much greater than during the pulse.
1996,
08.
Abstract:
By measuring threshold and using traveling wave amplification, the small signal gain coefficient and storage efficiency of a novel multi –slab Nd:glass laser amplifier designed and fabricated by us have been determined experimentally. It has been shown that a storage efficiency of 3.84% has been achieved in the use of this amplifier, which is higher than that of the conventional amplifier. Furthermore, the multi –slab laser amplifier has the potential advantage of providing the high power and good beam quality.
By measuring threshold and using traveling wave amplification, the small signal gain coefficient and storage efficiency of a novel multi –slab Nd:glass laser amplifier designed and fabricated by us have been determined experimentally. It has been shown that a storage efficiency of 3.84% has been achieved in the use of this amplifier, which is higher than that of the conventional amplifier. Furthermore, the multi –slab laser amplifier has the potential advantage of providing the high power and good beam quality.
1996,
08.
Abstract:
Experimental investigation of 0.53m m laser –plasma interaction were conducted on Shenguang–I laser facility, with one of its two beams irradiating on gold disks. The absorption、X –ray conversion、stimulated Raman scattering、hot electrons generation and ions emission were investigated. Experimental results show that absorption and X ray conversion are enhanced, SRS and hot electrons generating were suppressed by shortening laser wavelength in comparision with 1.053μm laser.
Experimental investigation of 0.53m m laser –plasma interaction were conducted on Shenguang–I laser facility, with one of its two beams irradiating on gold disks. The absorption、X –ray conversion、stimulated Raman scattering、hot electrons generation and ions emission were investigated. Experimental results show that absorption and X ray conversion are enhanced, SRS and hot electrons generating were suppressed by shortening laser wavelength in comparision with 1.053μm laser.
1996,
08.
Abstract:
The extended Ziman formula is employed to calculate electron conductive opacities of hot dense plasma. All required parameters in the formula are calculated by using relativistic self – consistent ion –sphere model. The degenerate effect is described by the Fermi –Dirac distribution. A parametric structure factor is used to consider the effect of ionic structure. The differential cross section for the elastic scattering of electrons is computed by the partial –wave expansion method. The results are compared with experimental and other available theoretical values.
The extended Ziman formula is employed to calculate electron conductive opacities of hot dense plasma. All required parameters in the formula are calculated by using relativistic self – consistent ion –sphere model. The degenerate effect is described by the Fermi –Dirac distribution. A parametric structure factor is used to consider the effect of ionic structure. The differential cross section for the elastic scattering of electrons is computed by the partial –wave expansion method. The results are compared with experimental and other available theoretical values.
1996,
08.
Abstract:
The amplitude stability system of the 200kW RF generator had been completed and successfully used in the injector (SFC) of HIRFL is 1988. The system can be equivalent to a negative feed-back circuit, which stabilizes the RF voltage of the cyclotron at the rate of 1.7 10-4, so that the extraction efficiency and energy spread of the beam can be improved.
The amplitude stability system of the 200kW RF generator had been completed and successfully used in the injector (SFC) of HIRFL is 1988. The system can be equivalent to a negative feed-back circuit, which stabilizes the RF voltage of the cyclotron at the rate of 1.7 10-4, so that the extraction efficiency and energy spread of the beam can be improved.
1996,
08.
Abstract:
A new way that harmonic emission is enhanced by a MOPA is presented in this paper. Through it, one can use a electron beam of low energy to acquire many kinds of short wavelength and high power coherent lights. Meanwhile, it can avoid high order harmonics of high power to cause mirror damage and keep a good optical beam quality.
A new way that harmonic emission is enhanced by a MOPA is presented in this paper. Through it, one can use a electron beam of low energy to acquire many kinds of short wavelength and high power coherent lights. Meanwhile, it can avoid high order harmonics of high power to cause mirror damage and keep a good optical beam quality.
