介绍了一种可以对等离子体进行快速扫描的新型气动式静电探针诊断系统 ,该系统由气动传送杆和一组四探针阵列组成。结合相应的数据采集和分析手段 ,能够在一次放电中得到边缘等离子体的电子温度 Te、电子密度ne 以及它们的涨落 Te Te、...介绍了一种可以对等离子体进行快速扫描的新型气动式静电探针诊断系统 ,该系统由气动传送杆和一组四探针阵列组成。结合相应的数据采集和分析手段 ,能够在一次放电中得到边缘等离子体的电子温度 Te、电子密度ne 以及它们的涨落 Te Te、 ne ne展开更多
As the startup phase of HL-2A operation and the first divertor tokamak device in China, it is important to identify the species of impurity, estimate the concentration of impurities and compare the different behaviors...As the startup phase of HL-2A operation and the first divertor tokamak device in China, it is important to identify the species of impurity, estimate the concentration of impurities and compare the different behaviors of radiation in limiter and divertor configurationt. In startup phase of HL-2A, glowing discharge cleaning （GDC） is used as a conventional wall conditioning technology and titanium gettering is used occasionally in closed divertor chamber during SN configuration discharges phase.展开更多
The 1 MW/68 GHz/1 s ECRH system of HL-2A device is being designed or fabricated. The O mode wave beams are injected into plasma from low field side of the HL-2A tokomak. Because the EC wave can heat plasma locally, it...The 1 MW/68 GHz/1 s ECRH system of HL-2A device is being designed or fabricated. The O mode wave beams are injected into plasma from low field side of the HL-2A tokomak. Because the EC wave can heat plasma locally, it is a very versatile scheme which has been employed to heating, current drive, profile control, confinement improvement. Up to now, the basic physical and engineering parameters of the whole system have been fixed and the subsystems are being designed or fabricated.展开更多
Silicon drift detector(SDD) is used in the soft x-ray pulse height analyzer(PHA) to measure soft x-ray emissions in fusion plasmas. SDD has the virtues of high count rates and high energy resolution, and the good perf...Silicon drift detector(SDD) is used in the soft x-ray pulse height analyzer(PHA) to measure soft x-ray emissions in fusion plasmas. SDD has the virtues of high count rates and high energy resolution, and the good performances at work temperature of about -10 ℃ achieved by single stage peltier element. The performance and first experimental results from SDD system are presented.展开更多
Electron cyclotron resonance heating and electron cyclotron current drive （ ECRH/ECCD ） have been developed significantly in recent years in many devices such as Tore Supra, JT-60U, Heliotron J. It has many advantag...Electron cyclotron resonance heating and electron cyclotron current drive （ ECRH/ECCD ） have been developed significantly in recent years in many devices such as Tore Supra, JT-60U, Heliotron J. It has many advantages over other means of heating and current drive. The EC power can be injected as narrow gaussian beams, giving rise to so highly localized power deposition as to make ECRH an ideal candidate for local MHD control.展开更多
Two new solutions for non-constant-α force-free magnetic field are found analytically. Implications of the results to astrophysical solar plasmas as well tokamak plasmas are discussed.
LHCD experiment has been carried through in HL-1M tokamak since 1995, and the work is successful. This years the LHCD experiment would go ahead on the HL-2A tokamak that had been improved from HL-1M system.
Several high performance tokamak operation regimes have been achieved experimentally in the experiments with the peaked density profiles. The regimes include the improved Ohmic confinement in ASDEX, the pellet enhance...Several high performance tokamak operation regimes have been achieved experimentally in the experiments with the peaked density profiles. The regimes include the improved Ohmic confinement in ASDEX, the pellet enhanced performance mode in Alcator-C, and the super-shot mode in TFTR. In these regimes, peaked core density profiles are always existent, and almost always go with the internal transport barriers, these barriers generally produced by sheared radial electric field. In addition to enhance confinement, the peaked density profile is also needed for the optimized fusion reaction rate and alpha heating power in tokamak plasma, and combined peaked density profile and peaked temperature profile, would make the ignition condition easy obtained. It is desirable to seek and analyze the density profile control schemes that effectively lead to density profile peaking in particle transports experimental investigation.展开更多
in order to study non-indutive plasma current production, the lower hybrid current drive（LHCD） experiment on the HL-2A tokamak is carried out. Simultaneously a microcomputer has been used to control the whole LHCD s...in order to study non-indutive plasma current production, the lower hybrid current drive（LHCD） experiment on the HL-2A tokamak is carried out. Simultaneously a microcomputer has been used to control the whole LHCD system. During the experiment this year, we can monitor and protect the LHCD system by use of the microcomputer control system, which will imediately switch off the microwave power to be launched into the tokamak if the plasma is disrupted. All this ensure that the microwave is injected into the equipment correctly.展开更多
The main mission the HL-2A tokamak is of the experiments on to explore the divertor physics and to investigate the plasma confinement, transport and instabilities with high power auxiliary heating and advanced fuellin...The main mission the HL-2A tokamak is of the experiments on to explore the divertor physics and to investigate the plasma confinement, transport and instabilities with high power auxiliary heating and advanced fuelling, it is necessary to develop more new diagnostics and increase the spatial and temporal resolutions of the measurements for exist system. Up to now, about 30 diagnostic systems have been moved from HL-1M to HL-2A tokamak. Other 10 diagnostic systems are being designed and installed on the device. In developed in last 2 years, will be presented.展开更多
The target of nuclear fusion research is to realize effective and sustainable fusion reaction of hydrogen isotope ions and to get the thermonuclear energy economically. Naturally the parameters of plasma ions are of...The target of nuclear fusion research is to realize effective and sustainable fusion reaction of hydrogen isotope ions and to get the thermonuclear energy economically. Naturally the parameters of plasma ions are of importance and measurement of the parameters of ions has been an essential concern to the nuclear fusion research work since 1950s. However, the ions are confined by the mag- netic field, one can measure the neutral particles emitting from the plasma to obtain the parameters of ions. The diagnosing of neutral particles is a method by measuring the neutral particles from the plasma to obtain the information （such as energy） of ions, and it is important and foundational to the experi ments as well.展开更多
In a tokamak plasma, shear Alfvén waves （SAWs） are generally characterized by a continuous spectrum with gaps, due topoloidal symmetry breaking. For low frequencies, ｜ω｜〈〈｜ωA｜=νA/qR, it has been shown ...In a tokamak plasma, shear Alfvén waves （SAWs） are generally characterized by a continuous spectrum with gaps, due topoloidal symmetry breaking. For low frequencies, ｜ω｜〈〈｜ωA｜=νA/qR, it has been shown that the SAW continuum can becomeunstable due to finite ion temperature gradient. Here, νA is the Alfvén speed, q and R are the safety factor and the major radius of the flux surface, respectively. Recently, it has been shown, with the multiple scale asymptotic technique, that discrete modes may exist in an unstable shear Alfvén continuous spectrum, due to finite ion Larmor radius （FLR） and finite drift-orbit width （FOW） effects in tokamak plasmas which are stable with respect to ideal magnetohydrodynamic （MHD） instabilities .展开更多
When the major disruption occurs, it can not only generate great heat loads on the first wall and divertor plates, but also leads to the large electromagnetic force because of the halo current. This large electromagne...When the major disruption occurs, it can not only generate great heat loads on the first wall and divertor plates, but also leads to the large electromagnetic force because of the halo current. This large electromagnetic force is very dangerous to the invessel components of the divertor and vacuum vessel. Therefore, how to avoid the disruption is an important issue on tokamak operation. To control and mitigate the major disruptions, the mechanism and the characters of the disruption have to be well understood.展开更多
In recent years, the high density plasma in the range of 10^19～ 10^20m^-3 have been operated in large or middle tokamak device in the world. A muhichannel far infrared interferometer for profile measurement of plasma...In recent years, the high density plasma in the range of 10^19～ 10^20m^-3 have been operated in large or middle tokamak device in the world. A muhichannel far infrared interferometer for profile measurement of plasma density on HL-2A divertor tokamak is being developed, however the design of the interferometer will appear many new problem in face of experimental environment of the HL-2A divertor device, such as how to make both transmission and arrangement of optics of the interferometer, the effect of electromo- tive force on device and how about the vibration etc. According to the eight windows setting on the largest flange of the device we have to design a Michelson-type FIR laser interferometer with 8 probing channels and eight concave mirrors must be attached it to the inner wall of the vacuum vessel of the device. Therefore, there are many problems should be taken into account to resolve, for example, （ 1 ） the vibration-proof consider for muhichannel interferometer and HCN laser, （2） the stabilization and reliability of the mirror frame uum vessel, the mirrors, hanging on internal wall of vachow to prevent the sputtering to （3） the vacuum seal of the windows and the design of mobile seal for the shutter to avoid the sputter coating of plasma,展开更多
HL-2A is a new middle-sized tokamak device with two closed divertors. In 2004 campaign siliconization as a wall condition has been first done on HL-2A since the starting operation of the device. By using sil-iconizati...HL-2A is a new middle-sized tokamak device with two closed divertors. In 2004 campaign siliconization as a wall condition has been first done on HL-2A since the starting operation of the device. By using sil-iconization we observed that impurity has been obviously decreased. The character of the siliconization and the effect of wall condition on plasma have been investigated as well as on the wall recycling.展开更多
HL-2A tokamak, the first tokamak with divertor in China, has been constructed and put into operation in 2002. The main parameters are R=1.65 m, a=0.4 m, BT=2.8 T, Ip = 0. 48 MA. The divertor of HL-2A is unique, becaus...HL-2A tokamak, the first tokamak with divertor in China, has been constructed and put into operation in 2002. The main parameters are R=1.65 m, a=0.4 m, BT=2.8 T, Ip = 0. 48 MA. The divertor of HL-2A is unique, because it is characterized with a large closed divertor chamber. The device has double divertor chamber, but now it is operating with lower single null configuration to study the physics of divertor for the next step design of a divertor. Supersonic molecular beam injection （SMBI） system with LN2 cooling trap was first installed and demonstrated on the HL-2A tokamak in 2004. The first results of SMBI into HL-2A plasma are to demonstrate the function of the HL-2A divertor and to observe the cold pulse propagation during multi-pulse SMBI on HL-2A Tokamak.展开更多
文摘As the startup phase of HL-2A operation and the first divertor tokamak device in China, it is important to identify the species of impurity, estimate the concentration of impurities and compare the different behaviors of radiation in limiter and divertor configurationt. In startup phase of HL-2A, glowing discharge cleaning （GDC） is used as a conventional wall conditioning technology and titanium gettering is used occasionally in closed divertor chamber during SN configuration discharges phase.
文摘The 1 MW/68 GHz/1 s ECRH system of HL-2A device is being designed or fabricated. The O mode wave beams are injected into plasma from low field side of the HL-2A tokomak. Because the EC wave can heat plasma locally, it is a very versatile scheme which has been employed to heating, current drive, profile control, confinement improvement. Up to now, the basic physical and engineering parameters of the whole system have been fixed and the subsystems are being designed or fabricated.
基金Yunnan Provincial Natural Science Foundation(2007A044 M)
文摘Silicon drift detector(SDD) is used in the soft x-ray pulse height analyzer(PHA) to measure soft x-ray emissions in fusion plasmas. SDD has the virtues of high count rates and high energy resolution, and the good performances at work temperature of about -10 ℃ achieved by single stage peltier element. The performance and first experimental results from SDD system are presented.
文摘Electron cyclotron resonance heating and electron cyclotron current drive （ ECRH/ECCD ） have been developed significantly in recent years in many devices such as Tore Supra, JT-60U, Heliotron J. It has many advantages over other means of heating and current drive. The EC power can be injected as narrow gaussian beams, giving rise to so highly localized power deposition as to make ECRH an ideal candidate for local MHD control.
基金The project supported by National Natural Science Foundation of China under Grant No. 10475009 and the New Century Excellent Talents in Universities of China. The author would like to thank Prof. Y.N. Huang for useful discussions.
文摘Two new solutions for non-constant-α force-free magnetic field are found analytically. Implications of the results to astrophysical solar plasmas as well tokamak plasmas are discussed.
文摘LHCD experiment has been carried through in HL-1M tokamak since 1995, and the work is successful. This years the LHCD experiment would go ahead on the HL-2A tokamak that had been improved from HL-1M system.
文摘Several high performance tokamak operation regimes have been achieved experimentally in the experiments with the peaked density profiles. The regimes include the improved Ohmic confinement in ASDEX, the pellet enhanced performance mode in Alcator-C, and the super-shot mode in TFTR. In these regimes, peaked core density profiles are always existent, and almost always go with the internal transport barriers, these barriers generally produced by sheared radial electric field. In addition to enhance confinement, the peaked density profile is also needed for the optimized fusion reaction rate and alpha heating power in tokamak plasma, and combined peaked density profile and peaked temperature profile, would make the ignition condition easy obtained. It is desirable to seek and analyze the density profile control schemes that effectively lead to density profile peaking in particle transports experimental investigation.
文摘in order to study non-indutive plasma current production, the lower hybrid current drive（LHCD） experiment on the HL-2A tokamak is carried out. Simultaneously a microcomputer has been used to control the whole LHCD system. During the experiment this year, we can monitor and protect the LHCD system by use of the microcomputer control system, which will imediately switch off the microwave power to be launched into the tokamak if the plasma is disrupted. All this ensure that the microwave is injected into the equipment correctly.
文摘The main mission the HL-2A tokamak is of the experiments on to explore the divertor physics and to investigate the plasma confinement, transport and instabilities with high power auxiliary heating and advanced fuelling, it is necessary to develop more new diagnostics and increase the spatial and temporal resolutions of the measurements for exist system. Up to now, about 30 diagnostic systems have been moved from HL-1M to HL-2A tokamak. Other 10 diagnostic systems are being designed and installed on the device. In developed in last 2 years, will be presented.
文摘The target of nuclear fusion research is to realize effective and sustainable fusion reaction of hydrogen isotope ions and to get the thermonuclear energy economically. Naturally the parameters of plasma ions are of importance and measurement of the parameters of ions has been an essential concern to the nuclear fusion research work since 1950s. However, the ions are confined by the mag- netic field, one can measure the neutral particles emitting from the plasma to obtain the parameters of ions. The diagnosing of neutral particles is a method by measuring the neutral particles from the plasma to obtain the information （such as energy） of ions, and it is important and foundational to the experi ments as well.
基金Supported by the National Natural Science Foundation of China（10135020）
文摘In a tokamak plasma, shear Alfvén waves （SAWs） are generally characterized by a continuous spectrum with gaps, due topoloidal symmetry breaking. For low frequencies, ｜ω｜〈〈｜ωA｜=νA/qR, it has been shown that the SAW continuum can becomeunstable due to finite ion temperature gradient. Here, νA is the Alfvén speed, q and R are the safety factor and the major radius of the flux surface, respectively. Recently, it has been shown, with the multiple scale asymptotic technique, that discrete modes may exist in an unstable shear Alfvén continuous spectrum, due to finite ion Larmor radius （FLR） and finite drift-orbit width （FOW） effects in tokamak plasmas which are stable with respect to ideal magnetohydrodynamic （MHD） instabilities .
文摘When the major disruption occurs, it can not only generate great heat loads on the first wall and divertor plates, but also leads to the large electromagnetic force because of the halo current. This large electromagnetic force is very dangerous to the invessel components of the divertor and vacuum vessel. Therefore, how to avoid the disruption is an important issue on tokamak operation. To control and mitigate the major disruptions, the mechanism and the characters of the disruption have to be well understood.
文摘In recent years, the high density plasma in the range of 10^19～ 10^20m^-3 have been operated in large or middle tokamak device in the world. A muhichannel far infrared interferometer for profile measurement of plasma density on HL-2A divertor tokamak is being developed, however the design of the interferometer will appear many new problem in face of experimental environment of the HL-2A divertor device, such as how to make both transmission and arrangement of optics of the interferometer, the effect of electromo- tive force on device and how about the vibration etc. According to the eight windows setting on the largest flange of the device we have to design a Michelson-type FIR laser interferometer with 8 probing channels and eight concave mirrors must be attached it to the inner wall of the vacuum vessel of the device. Therefore, there are many problems should be taken into account to resolve, for example, （ 1 ） the vibration-proof consider for muhichannel interferometer and HCN laser, （2） the stabilization and reliability of the mirror frame uum vessel, the mirrors, hanging on internal wall of vachow to prevent the sputtering to （3） the vacuum seal of the windows and the design of mobile seal for the shutter to avoid the sputter coating of plasma,
文摘HL-2A is a new middle-sized tokamak device with two closed divertors. In 2004 campaign siliconization as a wall condition has been first done on HL-2A since the starting operation of the device. By using sil-iconization we observed that impurity has been obviously decreased. The character of the siliconization and the effect of wall condition on plasma have been investigated as well as on the wall recycling.
文摘HL-2A tokamak, the first tokamak with divertor in China, has been constructed and put into operation in 2002. The main parameters are R=1.65 m, a=0.4 m, BT=2.8 T, Ip = 0. 48 MA. The divertor of HL-2A is unique, because it is characterized with a large closed divertor chamber. The device has double divertor chamber, but now it is operating with lower single null configuration to study the physics of divertor for the next step design of a divertor. Supersonic molecular beam injection （SMBI） system with LN2 cooling trap was first installed and demonstrated on the HL-2A tokamak in 2004. The first results of SMBI into HL-2A plasma are to demonstrate the function of the HL-2A divertor and to observe the cold pulse propagation during multi-pulse SMBI on HL-2A Tokamak.
