A magnetic field produced by a current flowing through the plasma grid(PG) is one of the solutions to reduce the collisional loss of negative ions in a negative ion source, which reduces the electron temperature in fr...A magnetic field produced by a current flowing through the plasma grid(PG) is one of the solutions to reduce the collisional loss of negative ions in a negative ion source, which reduces the electron temperature in front of the PG. However, the magnetic field diffused into the driver has some influence on the plasma outflowing. In order to investigate the effect of changing this magnetic field on the outflowing of plasma from the driver, a circular ring(absorber) of high permeability iron has been introduced at the driver exit, which can reduce the magnetic field around it and improve plasma outflowing. With the application of the absorber, the electron density is increased by about 35%, and the extraction current measured from the extraction grid is increased from 1.02 A to 1.29 A. The results of the extraction experiment with cesium injection show that both the extraction grid(EG) current and H-current are increased when the absorber is introduced.展开更多
Long pulse operation of high power ion source is the requirement of fusion science research on neutral beam injector. A breakdown of accelerator column is drastically increased when operating with high beam energy and...Long pulse operation of high power ion source is the requirement of fusion science research on neutral beam injector. A breakdown of accelerator column is drastically increased when operating with high beam energy and long beam duration. To extend the pulse length, which was stopped with every breakdown so far, the beam re-starting technology was developed and utilized. As a result, the voltage drop of every power supply due to breakdown was recovered within a time of 90 ms and beam pulse length was extended much longer than the case before this improvement. The details of the beam re-starting technology and the preliminary results were presented in this manuscript.展开更多
As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency (RF) ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and...As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency (RF) ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and high reliability. In addition, it easily achieves long-pulse steady-state operation. During the process of the development and testing of the RF ion source, a lot of original experimental data will be generated. Therefore, it is necessary to develop a stable and reliable computer data acquisition and processing application system for realizing the functions of data acquisition, storage, access, and real-time monitoring. In this paper, the development of a data acquisition and processing application system for the RF ion source is presented. The hardware platform is based on the PXI system and the software is programmed on the LabVIEW development environment. The key technologies that are used for the implementation of this software programming mainly include the long-pulse data acquisition technology, multi- threading processing technology, transmission control communication protocol, and the Lempel-Ziv-Oberhumer data compression algorithm. Now, this design has been tested and applied on the RF ion source. The test results show that it can work reliably and steadily. With the help of this design, the stable plasma discharge data of the RF ion source are collected, stored, accessed, and monitored in real-time. It is shown that it has a very practical application significance for the RF experiments.展开更多
In order to study the key technology and physics of RF driven negative ion source for neutral beam injector in China, the Hefei utility negative ions test equipment with RF source was developed at Institute of Plasma ...In order to study the key technology and physics of RF driven negative ion source for neutral beam injector in China, the Hefei utility negative ions test equipment with RF source was developed at Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). Its negative ion source can be equipped with single or double RF drivers. There is a plasma expansion chamber with depth of 19 mm and an enhanced filter field. A three electrodes negative ion accelerator was employed to extract and accelerate the negative ions, which are plasma grid,extraction grid and ground grid. And there are several diagnostic tools for the plasma and beam parameters measurement. The characteristics of plasma generation, negative ion production and extraction were studied on the test equipment. The negative ion beam was extracted from the RF driven negative ion source for the first time. The detailed structure and main results are presented in this article.展开更多
In order to understand the physics and pre-study the engineering issues for radio frequency(RF)negative beam source,a prototype source with a single driver and three-electrode accelerator was developed.Recently,the be...In order to understand the physics and pre-study the engineering issues for radio frequency(RF)negative beam source,a prototype source with a single driver and three-electrode accelerator was developed.Recently,the beam source was tested on the RF source test facility with RF plasma generation,negative ion production and extraction.A magnetic filter system and a Cs injection system were employed to enhance the negative ion production.As a result,a long pulse of 105 s negative ion beam with current density of 153 A m-2 was repeatedly extracted successfully.The source pressure is 0.6 Pa and the ratio of co-extracted electron and negative ion current is around0.3.The details of design and experimental results of beam source were shown in this letter.展开更多
A 16 kV/20 A power supply was developed for the extraction grid of prototype radio frequency(RF) ion source of neutral beam injector. To acquire the state signals of extraction grid power supply(EGPS) and control ...A 16 kV/20 A power supply was developed for the extraction grid of prototype radio frequency(RF) ion source of neutral beam injector. To acquire the state signals of extraction grid power supply(EGPS) and control the operation of the EGPS, a data acquisition and control system has been developed. This system mainly consists of interlock protection circuit board, photoelectric conversion circuit, optical fibers, industrial compact peripheral component interconnect(CPCI) computer and host computer. The human machine interface of host computer delivers commands and data to program of the CPCI computer, as well as offers a convenient client for setting parameters and displaying EGPS status. The CPCI computer acquires the status of the power supply. The system can turn-off the EGPS quickly when the faults of EGPS occur. The system has been applied to the EGPS of prototype RF ion source. Test results show that the data acquisition and control system for the EGPS can meet the requirements of the operation of prototype RF ion source.展开更多
In the 2016 EAST experimental campaign,a steady-state long-pulse H-mode discharge with an ITER-like tungsten divertor lasting longer than one minute has been obtained using only RF heating and current drive,through an...In the 2016 EAST experimental campaign,a steady-state long-pulse H-mode discharge with an ITER-like tungsten divertor lasting longer than one minute has been obtained using only RF heating and current drive,through an integrated control of the wall conditioning,plasma configuration,divertor heat flux,particle exhaust,impurity management,and effective coupling of multiple RF heating and current drive sources at high injected power.The plasma current(Ip - 0.45 MA) was fully-noninductively driven(Vloop 〈 0.0 V) by a combination of-2.5 MW LHW,-0.4 MW ECH and -0.8 MW ICRF.This result demonstrates the progress of physics and technology studies on EAST,and will benefit the physics basis for steady state operation of ITER and CFETR.展开更多
A radio frequency(RF) ion source was developed for neutral beam injector in Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). A cylindrical driver based RF plasma source was tested and optimized for lon...A radio frequency(RF) ion source was developed for neutral beam injector in Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). A cylindrical driver based RF plasma source was tested and optimized for long pulse operation. Recently, the plasma source achieved 1000 s stable plasma discharge with RF power of 35 k W and source pressure of 0.7 Pa for the first time.The heat loading on each of driver components such as the Faraday shield(FS), RF coil and expansion chamber was measured by the water flow calorimeter system. The experiment results showed that FS is the component with highest heat loading and the heat loading on FS was about 65.8% of total heat loading on source. The details of the long pulse operation of RF plasma source are presented in this paper.展开更多
Optical emission spectroscopy(OES)using the trace rare gases of Ar and Xe have been carried out in a radio frequency(RF)driven negative ion source at Institute of Plasma Physics,Chinese Academy of Science(ASIPP),in or...Optical emission spectroscopy(OES)using the trace rare gases of Ar and Xe have been carried out in a radio frequency(RF)driven negative ion source at Institute of Plasma Physics,Chinese Academy of Science(ASIPP),in order to determine the electron temperature and density of the hydrogen plasma.The line-ratio methods based on population models are applied to describe the radiation process of the excited state particles and establish their relations with the plasma parameters.The spectral lines from the argon and xenon excited state atoms with the wavelength of 750.4 and 828.0 nm are used to calculate the electron temperature based on the corona model.The argon ions emission lines with the wavelength of 480 and 488 nm are selected to calculate the electron density based on the collisional radiative model.OES has given the preliminary results of the electron temperature and density by varying the discharge gas pressure and RF power.According to the experimental results,the typical plasma parameters isTe2≈2-4 eV and ne≈1 x 1017-8 x 1017 m^-3 in front of plasma grid.展开更多
A radio frequency(RF)driven ion source is a very important component of a neutral beam injector for large magnetic confinement fusion devices.In order to study the key technology and physics of an RF driven ion source...A radio frequency(RF)driven ion source is a very important component of a neutral beam injector for large magnetic confinement fusion devices.In order to study the key technology and physics of an RF driven ion source for a neutral beam injector in China,an RF ion source test facility was developed at the Institute of Plasma Physics,Chinese Academy of Sciences.In this paper,a two-dimensional fluid model is used to simulate the fundamental physical characteristics of RF plasma discharge.Simulation results show the relationship of the characteristics of plasma(such as electron density and electron temperature)and RF power and gas pressure.In order to verify the effectiveness of the model,the characteristics of the plasma are investigated using a Langmuir probe.In this paper,experimental and simulation results are presented,and the possible reasons for the discrepancies between them are given.This paper can help us understand the characteristics of RF plasma discharge,and give a basis for further R&D for an RF ion source.展开更多
基金supported by the Comprehensive Research Facility for Fusion Technology Program of China(No.2018-000052-73-01-001228)National Natural Science Foundation of China(No.11975264)。
文摘A magnetic field produced by a current flowing through the plasma grid(PG) is one of the solutions to reduce the collisional loss of negative ions in a negative ion source, which reduces the electron temperature in front of the PG. However, the magnetic field diffused into the driver has some influence on the plasma outflowing. In order to investigate the effect of changing this magnetic field on the outflowing of plasma from the driver, a circular ring(absorber) of high permeability iron has been introduced at the driver exit, which can reduce the magnetic field around it and improve plasma outflowing. With the application of the absorber, the electron density is increased by about 35%, and the extraction current measured from the extraction grid is increased from 1.02 A to 1.29 A. The results of the extraction experiment with cesium injection show that both the extraction grid(EG) current and H-current are increased when the absorber is introduced.
基金supported by National Natural Science Foundation of China(Nos.11675215,11575240)the Key Program of Research and Development of Hefei Science Center,CAS(No.2016HSC-KPRD002)the National Key R&D Program of China(No.2017YFE300101)
文摘Long pulse operation of high power ion source is the requirement of fusion science research on neutral beam injector. A breakdown of accelerator column is drastically increased when operating with high beam energy and long beam duration. To extend the pulse length, which was stopped with every breakdown so far, the beam re-starting technology was developed and utilized. As a result, the voltage drop of every power supply due to breakdown was recovered within a time of 90 ms and beam pulse length was extended much longer than the case before this improvement. The details of the beam re-starting technology and the preliminary results were presented in this manuscript.
基金the NBI team and the partial support of National Natural Science Foundation of China (No. 61363019)National Natural Science Foundation of Qinghai Province (No. 2014-ZJ-718)
文摘As the key ion source component of nuclear fusion auxiliary heating devices, the radio frequency (RF) ion source is developed and applied gradually to offer a source plasma with the advantages of ease of control and high reliability. In addition, it easily achieves long-pulse steady-state operation. During the process of the development and testing of the RF ion source, a lot of original experimental data will be generated. Therefore, it is necessary to develop a stable and reliable computer data acquisition and processing application system for realizing the functions of data acquisition, storage, access, and real-time monitoring. In this paper, the development of a data acquisition and processing application system for the RF ion source is presented. The hardware platform is based on the PXI system and the software is programmed on the LabVIEW development environment. The key technologies that are used for the implementation of this software programming mainly include the long-pulse data acquisition technology, multi- threading processing technology, transmission control communication protocol, and the Lempel-Ziv-Oberhumer data compression algorithm. Now, this design has been tested and applied on the RF ion source. The test results show that it can work reliably and steadily. With the help of this design, the stable plasma discharge data of the RF ion source are collected, stored, accessed, and monitored in real-time. It is shown that it has a very practical application significance for the RF experiments.
基金supported by the Key Program of Research and Development of Hefei Science Center,CAS(No.2016HSCKPRD002)National Natural Science Foundation of China(Nos.11505224,11505225,11575240,11675215,11675216)
文摘In order to study the key technology and physics of RF driven negative ion source for neutral beam injector in China, the Hefei utility negative ions test equipment with RF source was developed at Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). Its negative ion source can be equipped with single or double RF drivers. There is a plasma expansion chamber with depth of 19 mm and an enhanced filter field. A three electrodes negative ion accelerator was employed to extract and accelerate the negative ions, which are plasma grid,extraction grid and ground grid. And there are several diagnostic tools for the plasma and beam parameters measurement. The characteristics of plasma generation, negative ion production and extraction were studied on the test equipment. The negative ion beam was extracted from the RF driven negative ion source for the first time. The detailed structure and main results are presented in this article.
基金supported by the Comprehensive Research Facility for Fusion Technology Program of China(No.2018-000052-73-01-001228)
文摘In order to understand the physics and pre-study the engineering issues for radio frequency(RF)negative beam source,a prototype source with a single driver and three-electrode accelerator was developed.Recently,the beam source was tested on the RF source test facility with RF plasma generation,negative ion production and extraction.A magnetic filter system and a Cs injection system were employed to enhance the negative ion production.As a result,a long pulse of 105 s negative ion beam with current density of 153 A m-2 was repeatedly extracted successfully.The source pressure is 0.6 Pa and the ratio of co-extracted electron and negative ion current is around0.3.The details of design and experimental results of beam source were shown in this letter.
基金supported by National Natural Science Foundation of China(Contract Nos.11505225&11675216)Foundation of ASIPP(Contract No.DSJJ-15-GC03)the Key Program of Research and Development of Hefei Science Center,CAS(2016HSC-KPRD002)
文摘A 16 kV/20 A power supply was developed for the extraction grid of prototype radio frequency(RF) ion source of neutral beam injector. To acquire the state signals of extraction grid power supply(EGPS) and control the operation of the EGPS, a data acquisition and control system has been developed. This system mainly consists of interlock protection circuit board, photoelectric conversion circuit, optical fibers, industrial compact peripheral component interconnect(CPCI) computer and host computer. The human machine interface of host computer delivers commands and data to program of the CPCI computer, as well as offers a convenient client for setting parameters and displaying EGPS status. The CPCI computer acquires the status of the power supply. The system can turn-off the EGPS quickly when the faults of EGPS occur. The system has been applied to the EGPS of prototype RF ion source. Test results show that the data acquisition and control system for the EGPS can meet the requirements of the operation of prototype RF ion source.
基金supported by the National Magnetic Conlinement Fusion Science Program of China(Nos.2015GB102000 and 2015GB103000)
文摘In the 2016 EAST experimental campaign,a steady-state long-pulse H-mode discharge with an ITER-like tungsten divertor lasting longer than one minute has been obtained using only RF heating and current drive,through an integrated control of the wall conditioning,plasma configuration,divertor heat flux,particle exhaust,impurity management,and effective coupling of multiple RF heating and current drive sources at high injected power.The plasma current(Ip - 0.45 MA) was fully-noninductively driven(Vloop 〈 0.0 V) by a combination of-2.5 MW LHW,-0.4 MW ECH and -0.8 MW ICRF.This result demonstrates the progress of physics and technology studies on EAST,and will benefit the physics basis for steady state operation of ITER and CFETR.
基金supported by Key Program of Research and Development of Hefei Science Center,CAS (Grant No. 2016HSC-KPRD002)National Key R&D Program of China (Grant No. 2017YFE300101)National Natural Science Foundation of China (Grant Nos. 11505224,11505225,11505226,11675215)
文摘A radio frequency(RF) ion source was developed for neutral beam injector in Institute of Plasma Physics, Chinese Academy of Sciences(ASIPP). A cylindrical driver based RF plasma source was tested and optimized for long pulse operation. Recently, the plasma source achieved 1000 s stable plasma discharge with RF power of 35 k W and source pressure of 0.7 Pa for the first time.The heat loading on each of driver components such as the Faraday shield(FS), RF coil and expansion chamber was measured by the water flow calorimeter system. The experiment results showed that FS is the component with highest heat loading and the heat loading on FS was about 65.8% of total heat loading on source. The details of the long pulse operation of RF plasma source are presented in this paper.
文摘Optical emission spectroscopy(OES)using the trace rare gases of Ar and Xe have been carried out in a radio frequency(RF)driven negative ion source at Institute of Plasma Physics,Chinese Academy of Science(ASIPP),in order to determine the electron temperature and density of the hydrogen plasma.The line-ratio methods based on population models are applied to describe the radiation process of the excited state particles and establish their relations with the plasma parameters.The spectral lines from the argon and xenon excited state atoms with the wavelength of 750.4 and 828.0 nm are used to calculate the electron temperature based on the corona model.The argon ions emission lines with the wavelength of 480 and 488 nm are selected to calculate the electron density based on the collisional radiative model.OES has given the preliminary results of the electron temperature and density by varying the discharge gas pressure and RF power.According to the experimental results,the typical plasma parameters isTe2≈2-4 eV and ne≈1 x 1017-8 x 1017 m^-3 in front of plasma grid.
基金National Natural Science Foundation of China(Nos.11675216,11905248,11975261,11975262,11975263,and 11975264)the Key Program of Research and Development of Hefei Science Center,CAS(Contract No.2016HSC-KPRD002)the National Key R&D Program of China(Nos.2017YFE0300101,2017YFE0300103,and 2017YFE0300503).
文摘A radio frequency(RF)driven ion source is a very important component of a neutral beam injector for large magnetic confinement fusion devices.In order to study the key technology and physics of an RF driven ion source for a neutral beam injector in China,an RF ion source test facility was developed at the Institute of Plasma Physics,Chinese Academy of Sciences.In this paper,a two-dimensional fluid model is used to simulate the fundamental physical characteristics of RF plasma discharge.Simulation results show the relationship of the characteristics of plasma(such as electron density and electron temperature)and RF power and gas pressure.In order to verify the effectiveness of the model,the characteristics of the plasma are investigated using a Langmuir probe.In this paper,experimental and simulation results are presented,and the possible reasons for the discrepancies between them are given.This paper can help us understand the characteristics of RF plasma discharge,and give a basis for further R&D for an RF ion source.