Gas chromatography/mass spectrometry （GC/MS） can only analyze volatile molecular compounds, and it has limitations when applied to determine the complex components of crude oils and hydrocarbon source rocks. Based o...Gas chromatography/mass spectrometry （GC/MS） can only analyze volatile molecular compounds, and it has limitations when applied to determine the complex components of crude oils and hydrocarbon source rocks. Based on Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR-MS） and GC/MS analyses, the molecular compositions of NSO compounds in extracts from the Permian Dalong Formation, Sichuan Basin and the Permian Lucaogou Formation, Junggar Basin in China were compared. Analyses of types of heteroatoms present （S~, $2, $3, OS, OS2, 02S, NS, and NOS compounds） suggest that marine shales from the Dalong Formation are mainly composed of carboxylic acids （02 com- pounds） with a high abundance of fatty acids, indicating a marine phytoplankton organic source. However, lacustrine shales from the Lucaogou Formation are dominated by pyrrolic compounds （N1 compounds） with abundant dibenzocar- bazole. It suggests that the organic source materials may be derived from lower aquatic organisms and lacustrine algae. Overall, FT-ICR-MS has potential for applications in analyses and determination of depositional environments and organic sources in petroleum geology.展开更多
Ion cyclotron resonance heating （ICRH） system which will provide at least than 10 MW heating power, with a frequency range from 25 MHz to 100 MHz, is being built up for the EAST. The system includes high-power and w...Ion cyclotron resonance heating （ICRH） system which will provide at least than 10 MW heating power, with a frequency range from 25 MHz to 100 MHz, is being built up for the EAST. The system includes high-power and wide-frequency radio amplifier, transmission line as well as resonant double loop （RDL） antenna. As a part of this system a sub-ICRH system unit with a ultimate output power of 2.5 MW was set up and employed for heating experiment. The maximum of the launched power reached 200 kW in 2008.展开更多
The classical prompt loss of fast ions produced by minority ion cyclotron resonance heating(ICRH)is studied by a guiding center orbit following code in the Experimental Advanced Superconducting Tokamak(EAST).It is fou...The classical prompt loss of fast ions produced by minority ion cyclotron resonance heating(ICRH)is studied by a guiding center orbit following code in the Experimental Advanced Superconducting Tokamak(EAST).It is found that the loss of fast ions produced by ICRH mainly appears in both ends of the resonance layer,while the loss of fast ions in the middle resonance layer is very small.The dominant fast loss comes from trapped ions,rather than from passing ions.Controlling the location of resonance layer at the plasma core may be more beneficial to the EAST tokamak ICRH.In addition,the loss distribution of fast ions is studied.The results show that the fast ions are mainly lost near the midplane in the poloidal direction,but almost uniformly in the toroidal direction.Moreover,we investigate the dependence of fast ion loss on the ICRH power.The simulation results show that the loss fraction of fast ions in both ends of the resonance region increases with the ion cyclotron range of frequencies(ICRF)power,but barely affects the loss of fast ions in the middle region.展开更多
One of the primary concerns associated with ion cyclotron resonance heating(ICRH)is the enhanced impurity sputtering resulting from radio frequency(RF)sheath formation near plasma-facing components(PFCs),such as limit...One of the primary concerns associated with ion cyclotron resonance heating(ICRH)is the enhanced impurity sputtering resulting from radio frequency(RF)sheath formation near plasma-facing components(PFCs),such as limiters.Developing a sputtering model integrated with RF sheath simulations allows for a more comprehensive understanding of the kinetic behavior of incident ions and their interactions with the limiter surface.We accordingly develop an impurity sputtering model“PMSAD”,which computes the sputtering yield(amount of impurity)on the limiter surface based on incident ion characteristics and predicts the spatial distribution of impurities.The model provides a robust method for understanding and analyzing the impurity sputtering process from limiter surfaces,which is crucial for preventing ICRH surface erosion and reducing edge and core plasma contamination.展开更多
A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconductin...A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids （Nb-Ti/Cu） and six superconducting sextupoles （Nb-Ti/Cu）. Different from the conventional supercon- ducting ECR magnetic structure, the SEC17AL Ⅱ includes three superconducting solenoid coils＇ that are located inside the superconducting sextupoles. The SECRAL Ⅱ can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL Ⅱ generating its self field of -8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at 〈200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL Ⅱ structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the based on our analysis, the stresses and deformations optimized. strains developments of a sextupole is reported. Finally, for its assembly of each SECRAL Ⅱ coil will be further展开更多
A program developed with COMSOL software integrates EAST four-strap antenna coupling with the double-stub Ferrite tuners(FT)impedance matching,obtaining physical quantities crucial for predicting the overall performan...A program developed with COMSOL software integrates EAST four-strap antenna coupling with the double-stub Ferrite tuners(FT)impedance matching,obtaining physical quantities crucial for predicting the overall performance of the ion cyclotron resonance heating(ICRH)antenna and matching system.These quantities encompass S-matrix,port complex impedance,reflection coefficients,electric field and voltage distribution,and optimal matching settings.In this study,we explore the relationship between S-matrix,reflection coefficients,port complex impedance,and frequency.Then,we analyze the impact of Faraday screens placement position and transparency,the distance from the Faraday screen(FS)to the current straps(CS),the relative distance between ports,and the characteristic impedance of the transmission line on the coupling characteristic impedance of the EAST ICRH system.Finally,we simulate the electric field distribution and voltage distribution of the EAST ICRH system for plasma heating with double-stub FT impedance matching.Using optimized parameters,the coupling power of the ICRH system can be approximately doubled.The results present herein may offer guidance for the design of high-power,long-pulse operation ICRH antenna systems.展开更多
A practical 2.45-GHz microwave-driven Cs-free H^- source was improved based on the experimental H^- source at Peking University（PKU）. Several structural improvements were implemented to meet the practical requiremen...A practical 2.45-GHz microwave-driven Cs-free H^- source was improved based on the experimental H^- source at Peking University（PKU）. Several structural improvements were implemented to meet the practical requirements of Xi＇an Proton Application Facility（XiPaf）. Firstly, the plasma chamber size was optimized to enhance the plasma intensity and stability. Secondly, the filter magnetic field and electron deflecting magnetic field were enhanced to reduce co-extracted electrons. Thirdly, a new two-electrode extraction system with farther electrode gap and enhanced water cooling ability to diminish spark and sputter during beam extraction was applied. At last, the direct H^- current measuring method was adopted by the arrangement of a new pair of bending magnets before Faraday cup（FC） to remove residual electrons. With these improvements, electron cyclotron resonance（ECR） magnetic field optimization experiments and operation parameter variation experiments were carried out on the H^- ion source and a maximum 8.5-mA pure H^- beam was extracted at 50 kV with the time structure of 100 Hz/0.3 ms. The root-mean-square（RMS） emittance of the beam is 0.25 Π·mm·mrad. This improved H^- source and extraction system were maintenance-free for more than 200 hours in operation.展开更多
An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of ...An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of fast ions in the HL-2A/3 tokamak.The E//B NPA contains three main units,i.e.the stripping unit,the analyzing unit and the detection unit.A gas stripping chamber was adopted as the stripping unit.The results of the simulations and beam tests for the stripping chamber are presented.Parallel electric and magnetic fields provided by a NdFeB permanent magnet and two parallel electric plates were designed and constructed for the analyzing unit.The calibration of the magnetic and electric fields was performed using a 50 kV electron cyclotron resonance ion source(ECRIS)platform.The detection unit consists of 32lutetium-yttrium oxyorthosilicate(LYSO)detector modules arranged in two rows.The response functions ofα,hydrogen ions(H^(+),H_(2)^(+)and H_(3)^(+))andγfor a detector module were measured with^(241)Am,^(137)Cs and^(152)Eu sources together with the 50 kV ECRIS platform.The overall results indicate that the designed E//B NPA device is capable of measuring the intensity of neutral hydrogen and deuteron atoms with energy higher than 20 keV.展开更多
Optical emission spectroscopy（OES）, as a simple in situ method without disturbing the plasma, has been performed for the plasma diagnosis of a 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion sour...Optical emission spectroscopy（OES）, as a simple in situ method without disturbing the plasma, has been performed for the plasma diagnosis of a 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion source at Peking University（PKU）. A spectrum measurement platform has been set up with the quartz-chamber electron cyclotron resonance（ECR） ion source [Patent Number： ZL 201110026605.4] and experiments were carried out recently. The electron temperature and electron density inside the ECR plasma chamber have been measured with the method of line intensity ratio of noble gas. Hydrogen plasma processes inside the discharge chamber are discussed based on the diagnostic results. What is more, the superiority of the method of line intensity ratio of noble gas is indicated with a comparison to line intensity ratio of hydrogen. Details will be presented in this paper.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 41672117)Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals (Project No. DMSM201413)Hubei Provincial Natural Science Foundation of China (Project No. 2017CFA027)
文摘Gas chromatography/mass spectrometry （GC/MS） can only analyze volatile molecular compounds, and it has limitations when applied to determine the complex components of crude oils and hydrocarbon source rocks. Based on Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR-MS） and GC/MS analyses, the molecular compositions of NSO compounds in extracts from the Permian Dalong Formation, Sichuan Basin and the Permian Lucaogou Formation, Junggar Basin in China were compared. Analyses of types of heteroatoms present （S~, $2, $3, OS, OS2, 02S, NS, and NOS compounds） suggest that marine shales from the Dalong Formation are mainly composed of carboxylic acids （02 com- pounds） with a high abundance of fatty acids, indicating a marine phytoplankton organic source. However, lacustrine shales from the Lucaogou Formation are dominated by pyrrolic compounds （N1 compounds） with abundant dibenzocar- bazole. It suggests that the organic source materials may be derived from lower aquatic organisms and lacustrine algae. Overall, FT-ICR-MS has potential for applications in analyses and determination of depositional environments and organic sources in petroleum geology.
基金supported by the JSPS-CAS Core-University Program in the field of Plasma and Nuclear Fusion
文摘Ion cyclotron resonance heating （ICRH） system which will provide at least than 10 MW heating power, with a frequency range from 25 MHz to 100 MHz, is being built up for the EAST. The system includes high-power and wide-frequency radio amplifier, transmission line as well as resonant double loop （RDL） antenna. As a part of this system a sub-ICRH system unit with a ultimate output power of 2.5 MW was set up and employed for heating experiment. The maximum of the launched power reached 200 kW in 2008.
基金supported by National Natural Science Foundation of China (No. 11805239)the Natural Science Foundation of Hunan Province (No. 2019JJ50011)
文摘The classical prompt loss of fast ions produced by minority ion cyclotron resonance heating(ICRH)is studied by a guiding center orbit following code in the Experimental Advanced Superconducting Tokamak(EAST).It is found that the loss of fast ions produced by ICRH mainly appears in both ends of the resonance layer,while the loss of fast ions in the middle resonance layer is very small.The dominant fast loss comes from trapped ions,rather than from passing ions.Controlling the location of resonance layer at the plasma core may be more beneficial to the EAST tokamak ICRH.In addition,the loss distribution of fast ions is studied.The results show that the fast ions are mainly lost near the midplane in the poloidal direction,but almost uniformly in the toroidal direction.Moreover,we investigate the dependence of fast ion loss on the ICRH power.The simulation results show that the loss fraction of fast ions in both ends of the resonance region increases with the ion cyclotron range of frequencies(ICRF)power,but barely affects the loss of fast ions in the middle region.
基金financially supported by the National MCF Energy R&D Program(Grant No.2022YFE03190100)the National Natural Science Foundation of China(Grant Nos.12422513,12105035,U21A20438)the Xiaomi Young Talents Program。
文摘One of the primary concerns associated with ion cyclotron resonance heating(ICRH)is the enhanced impurity sputtering resulting from radio frequency(RF)sheath formation near plasma-facing components(PFCs),such as limiters.Developing a sputtering model integrated with RF sheath simulations allows for a more comprehensive understanding of the kinetic behavior of incident ions and their interactions with the limiter surface.We accordingly develop an impurity sputtering model“PMSAD”,which computes the sputtering yield(amount of impurity)on the limiter surface based on incident ion characteristics and predicts the spatial distribution of impurities.The model provides a robust method for understanding and analyzing the impurity sputtering process from limiter surfaces,which is crucial for preventing ICRH surface erosion and reducing edge and core plasma contamination.
基金Supported by the National Natural Science Foundation of China under Grant No 11302225the China Postdoctoral Science Foundation under Grant Nos 2014M560820 and 2015T81071
文摘A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids （Nb-Ti/Cu） and six superconducting sextupoles （Nb-Ti/Cu）. Different from the conventional supercon- ducting ECR magnetic structure, the SEC17AL Ⅱ includes three superconducting solenoid coils＇ that are located inside the superconducting sextupoles. The SECRAL Ⅱ can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL Ⅱ generating its self field of -8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at 〈200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL Ⅱ structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the based on our analysis, the stresses and deformations optimized. strains developments of a sextupole is reported. Finally, for its assembly of each SECRAL Ⅱ coil will be further
基金supported by National Magnetic Confinement Fusion Energy Development Research Project(Nos.2022YFE03070003 and 2019YFE03070000)Natural Science Foundation of Hunan Province(No.2020JJ4515)+6 种基金Key Projects of Hunan Provincial Department of Education(No.20A432)the Government Sponsored Study Abroad Program of the Chinese Scholarship Council(CSC)(No.202108430056)Anhui Provincial Natural Science Foundation(No.2308085MA23)IAEA Coordinated Research Project F43026(No.26480)the National Key Research&Development Program of China(No.2018YFE0303103)National Natural Science Foundation of China(Nos.11875287 and 12275314)Anhui Provincial Key Research&Development Project(No.205258180096)。
文摘A program developed with COMSOL software integrates EAST four-strap antenna coupling with the double-stub Ferrite tuners(FT)impedance matching,obtaining physical quantities crucial for predicting the overall performance of the ion cyclotron resonance heating(ICRH)antenna and matching system.These quantities encompass S-matrix,port complex impedance,reflection coefficients,electric field and voltage distribution,and optimal matching settings.In this study,we explore the relationship between S-matrix,reflection coefficients,port complex impedance,and frequency.Then,we analyze the impact of Faraday screens placement position and transparency,the distance from the Faraday screen(FS)to the current straps(CS),the relative distance between ports,and the characteristic impedance of the transmission line on the coupling characteristic impedance of the EAST ICRH system.Finally,we simulate the electric field distribution and voltage distribution of the EAST ICRH system for plasma heating with double-stub FT impedance matching.Using optimized parameters,the coupling power of the ICRH system can be approximately doubled.The results present herein may offer guidance for the design of high-power,long-pulse operation ICRH antenna systems.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775007 and 11575013)
文摘A practical 2.45-GHz microwave-driven Cs-free H^- source was improved based on the experimental H^- source at Peking University（PKU）. Several structural improvements were implemented to meet the practical requirements of Xi＇an Proton Application Facility（XiPaf）. Firstly, the plasma chamber size was optimized to enhance the plasma intensity and stability. Secondly, the filter magnetic field and electron deflecting magnetic field were enhanced to reduce co-extracted electrons. Thirdly, a new two-electrode extraction system with farther electrode gap and enhanced water cooling ability to diminish spark and sputter during beam extraction was applied. At last, the direct H^- current measuring method was adopted by the arrangement of a new pair of bending magnets before Faraday cup（FC） to remove residual electrons. With these improvements, electron cyclotron resonance（ECR） magnetic field optimization experiments and operation parameter variation experiments were carried out on the H^- ion source and a maximum 8.5-mA pure H^- beam was extracted at 50 kV with the time structure of 100 Hz/0.3 ms. The root-mean-square（RMS） emittance of the beam is 0.25 Π·mm·mrad. This improved H^- source and extraction system were maintenance-free for more than 200 hours in operation.
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China(No.2018YFE0310200)National Natural Science Foundation of China(Nos.11705242,11805138 and 12175156)the Fundamental Research Funds for the Central Universities in China(Nos.YJ201820 and YJ201954)。
文摘An E//B neutral particle analyzer(NPA)has been designed and is under development at Sichuan University and Southwestern Institute of Physics.The main purpose of the E//B NPA is to measure the distribution function of fast ions in the HL-2A/3 tokamak.The E//B NPA contains three main units,i.e.the stripping unit,the analyzing unit and the detection unit.A gas stripping chamber was adopted as the stripping unit.The results of the simulations and beam tests for the stripping chamber are presented.Parallel electric and magnetic fields provided by a NdFeB permanent magnet and two parallel electric plates were designed and constructed for the analyzing unit.The calibration of the magnetic and electric fields was performed using a 50 kV electron cyclotron resonance ion source(ECRIS)platform.The detection unit consists of 32lutetium-yttrium oxyorthosilicate(LYSO)detector modules arranged in two rows.The response functions ofα,hydrogen ions(H^(+),H_(2)^(+)and H_(3)^(+))andγfor a detector module were measured with^(241)Am,^(137)Cs and^(152)Eu sources together with the 50 kV ECRIS platform.The overall results indicate that the designed E//B NPA device is capable of measuring the intensity of neutral hydrogen and deuteron atoms with energy higher than 20 keV.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11175009 and 11575013)
文摘Optical emission spectroscopy（OES）, as a simple in situ method without disturbing the plasma, has been performed for the plasma diagnosis of a 2.45 GHz permanent magnet electron cyclotron resonance（PMECR） ion source at Peking University（PKU）. A spectrum measurement platform has been set up with the quartz-chamber electron cyclotron resonance（ECR） ion source [Patent Number： ZL 201110026605.4] and experiments were carried out recently. The electron temperature and electron density inside the ECR plasma chamber have been measured with the method of line intensity ratio of noble gas. Hydrogen plasma processes inside the discharge chamber are discussed based on the diagnostic results. What is more, the superiority of the method of line intensity ratio of noble gas is indicated with a comparison to line intensity ratio of hydrogen. Details will be presented in this paper.
