Pub Date : 1991-10-01DOI: 10.1109/FUSION.1991.218824
J. Wight, R. Hong, J. Phillips
The fundamental parameters by which injected DIII-D neutral beam power is calculated have all been recently measured using waterflow calorimetry and target tile thermocouples. The measured neutralization efficiency is 66%, close to the modeled equilibrium value of 70% for a 75 kV deuterium beam. Waterflow calorimetry has proven to be a useful tool to measure the neutralization efficiency, contrary to earlier results. The beamline transmission efficiency has been measured for each beam independently, and averages about 78% among the beams. Finally, the drift duct reionization survival rate is 95%. By making use of the independence of preshot target tile temperature and duct reionization, interpretation of thermocouple data has yielded more accurate results.<>
{"title":"Recent DIII-D neutral beam calibration results","authors":"J. Wight, R. Hong, J. Phillips","doi":"10.1109/FUSION.1991.218824","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218824","url":null,"abstract":"The fundamental parameters by which injected DIII-D neutral beam power is calculated have all been recently measured using waterflow calorimetry and target tile thermocouples. The measured neutralization efficiency is 66%, close to the modeled equilibrium value of 70% for a 75 kV deuterium beam. Waterflow calorimetry has proven to be a useful tool to measure the neutralization efficiency, contrary to earlier results. The beamline transmission efficiency has been measured for each beam independently, and averages about 78% among the beams. Finally, the drift duct reionization survival rate is 95%. By making use of the independence of preshot target tile temperature and duct reionization, interpretation of thermocouple data has yielded more accurate results.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116847165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-10-01DOI: 10.1109/FUSION.1991.218718
D.D. Clow, D. Kellman
The DIII-D electron cyclotron heating (ECH) high-voltage power supply is controlled by a computer. Operational control is input via keyboard and mouse, and computer/power supply interface is accomplished with a computer-assisted monitoring and control (CAMAC) system. User-friendly tools allow the design and layout of simulated control panels on the computer screen. Panel controls and indicators can be changed, added or deleted, and simple editing of user-specific processes can quickly modify control and fault logic. Databases can be defined, and control panel functions are easily referred to various data channels. User-specific processes are written and linked using Fortran, to manage control and data acquisition through CAMAC. The resulting control system has significant advantages over the hardware it emulates: changes in logic, layout, and function are quickly and easily incorporated; data storage, retrieval, and processing are flexible and simply accomplished; and physical components subject to wear and degradation are minimized.<>
{"title":"Computer control of the high-voltage power supply for the DIII-D electron cyclotron heating system","authors":"D.D. Clow, D. Kellman","doi":"10.1109/FUSION.1991.218718","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218718","url":null,"abstract":"The DIII-D electron cyclotron heating (ECH) high-voltage power supply is controlled by a computer. Operational control is input via keyboard and mouse, and computer/power supply interface is accomplished with a computer-assisted monitoring and control (CAMAC) system. User-friendly tools allow the design and layout of simulated control panels on the computer screen. Panel controls and indicators can be changed, added or deleted, and simple editing of user-specific processes can quickly modify control and fault logic. Databases can be defined, and control panel functions are easily referred to various data channels. User-specific processes are written and linked using Fortran, to manage control and data acquisition through CAMAC. The resulting control system has significant advantages over the hardware it emulates: changes in logic, layout, and function are quickly and easily incorporated; data storage, retrieval, and processing are flexible and simply accomplished; and physical components subject to wear and degradation are minimized.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125338480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-10-01DOI: 10.1109/FUSION.1991.218934
T. E. Harris
On past DIII-D experiments involving the use of Varian VA-8060 gyrotrons for ECH (electron cyclotron heating) power, significant gyrotron heater-emission depletion was experienced for pulse widths >300 ms. This decline in heater-emission directly results in gyrotron-cathode current droop. Since RF power from gyrotrons decreases as cathode current decreases, it is necessary to maintain a constant cathode current level during gyrotron pulses for efficient gyrotron operation. Therefore, it was determined that a filament-heater control system should be developed for the Varian VGT-8011 gyrotron which will include cathode-current feedback. The author discusses the mechanisms used to regulate gyrotron filament-heater voltage by using cathode-current feedback. A 110 GHz ECH system has been completed and is operational using the active filament-heater control and regulation network that has been developed.<>
{"title":"Active heater control and regulation for the Varian VGT-80 11 gyrotron","authors":"T. E. Harris","doi":"10.1109/FUSION.1991.218934","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218934","url":null,"abstract":"On past DIII-D experiments involving the use of Varian VA-8060 gyrotrons for ECH (electron cyclotron heating) power, significant gyrotron heater-emission depletion was experienced for pulse widths >300 ms. This decline in heater-emission directly results in gyrotron-cathode current droop. Since RF power from gyrotrons decreases as cathode current decreases, it is necessary to maintain a constant cathode current level during gyrotron pulses for efficient gyrotron operation. Therefore, it was determined that a filament-heater control system should be developed for the Varian VGT-8011 gyrotron which will include cathode-current feedback. The author discusses the mechanisms used to regulate gyrotron filament-heater voltage by using cathode-current feedback. A 110 GHz ECH system has been completed and is operational using the active filament-heater control and regulation network that has been developed.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134296222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-09-30DOI: 10.1109/FUSION.1991.218819
H. D. de Esch, P. Massmann, A. Bickley, C. Challis, G. Deschamps, H. Falter, R. Hemsworth, T. Jones, D. Stork, L. Svensson, D. Young
The successful conversion of the JET, (Joint European Torus) neutral injectors to operate in helium has further enhanced the usefulness of neutral injection on JET. Each of the two injectors can now operate in H, D, /sup 3/He, or /sup 4/He. The operation of a long-pulse /sup 3/He NBI (neutral-beam injector) has been demonstrated for the first time. Up to 7 MW of /sup 4/He and 13 MW of /sup 3/He neutral beam power have been injected into JET. The beams have been operated at energies up to 150 keV, with pulse lengths up to 7 s.<>
JET (Joint European Torus)中性喷射器在氦气环境下的成功改造，进一步增强了JET中性喷射器的实用性。现在，两个注水井中的每一个都可以在H、D、/sup 3/He或/sup 4/He井中工作。首次演示了长脉冲/sup 3/He中性束注入器(NBI)的操作。高达7兆瓦的/sup 4/He和13兆瓦的/sup 3/He中性束功率已注入JET。这些光束的运行能量高达150 keV，脉冲长度可达7秒。
{"title":"Experience with helium neutral beam systems","authors":"H. D. de Esch, P. Massmann, A. Bickley, C. Challis, G. Deschamps, H. Falter, R. Hemsworth, T. Jones, D. Stork, L. Svensson, D. Young","doi":"10.1109/FUSION.1991.218819","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218819","url":null,"abstract":"The successful conversion of the JET, (Joint European Torus) neutral injectors to operate in helium has further enhanced the usefulness of neutral injection on JET. Each of the two injectors can now operate in H, D, /sup 3/He, or /sup 4/He. The operation of a long-pulse /sup 3/He NBI (neutral-beam injector) has been demonstrated for the first time. Up to 7 MW of /sup 4/He and 13 MW of /sup 3/He neutral beam power have been injected into JET. The beams have been operated at energies up to 150 keV, with pulse lengths up to 7 s.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115619921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-09-30DOI: 10.1109/FUSION.1991.218739
K. Holtrop, G. Jackson, K. Schaubel, A. Kellman
Helium glow discharge conditioning is used before every discharge in the DIII-D tokamak to desorb hydrogen and low Z impurities from the graphite and Inconel plasma facing surfaces. However, high gas pressure is required to initiate each glow discharge session and this requires frequent cycling of valves to protect pressure sensitive devices. To alleviate this mechanical fatigue an electron gun assisted glow system is being installed on the DIII-D vessel to lower the initiation pressure. Through the injection of electrons the initiation pressure of the helium glow discharge has been lowered by a factor of 70, bringing the initiation pressure within a factor of 2 of the minimum sustaining pressure of the glow discharge. This might also make possible pulsed glow conditioning, which would allow a lower average pressure during glow conditioning, reducing the heat load on proposed cryogenic pumping panels. Experimental results of the electron assist on He glow initiation and a scaling model for the electron gun assisted glow are presented.<>
{"title":"Glow discharge initiation with electron gun assist","authors":"K. Holtrop, G. Jackson, K. Schaubel, A. Kellman","doi":"10.1109/FUSION.1991.218739","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218739","url":null,"abstract":"Helium glow discharge conditioning is used before every discharge in the DIII-D tokamak to desorb hydrogen and low Z impurities from the graphite and Inconel plasma facing surfaces. However, high gas pressure is required to initiate each glow discharge session and this requires frequent cycling of valves to protect pressure sensitive devices. To alleviate this mechanical fatigue an electron gun assisted glow system is being installed on the DIII-D vessel to lower the initiation pressure. Through the injection of electrons the initiation pressure of the helium glow discharge has been lowered by a factor of 70, bringing the initiation pressure within a factor of 2 of the minimum sustaining pressure of the glow discharge. This might also make possible pulsed glow conditioning, which would allow a lower average pressure during glow conditioning, reducing the heat load on proposed cryogenic pumping panels. Experimental results of the electron assist on He glow initiation and a scaling model for the electron gun assisted glow are presented.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"131 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120894675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-09-30DOI: 10.1109/FUSION.1991.218823
Y. Oka, A. Ando, O. Kaneko, Y. Takeiri, K. Tsumori, R. Akiyama, T. Kawamoto, K. Mineo, T. Kurata, T. Kuroda
A test stand for the negative-ion-based NBI (neutral beam injector) for the LHD, currently under construction, has neutral beam capabilities of 2.5 MW at a beam energy of 125 keV (H/sup 0/)/250 keV (D/sup 0/) and pulse duration of 10 s. Components being developed are as follows: (1) a large and high current negative ion source which is immersed in vacuum and composed of a compact modular ion source; (2) a beam dump to remove high heat flux up to 1.6 kW/cm/sup 2/; (3) a high-pumping-speed (450 m/sup 3//s) cryopump; (4) a 250-kV power supply system using a GTO (gate turn-off thyristor); and (5) a controller system to vary the beam energy within 0.5 s.<>
{"title":"Construction of negative-ion-based neutral beam teststand for Large Helical Device (LHD)","authors":"Y. Oka, A. Ando, O. Kaneko, Y. Takeiri, K. Tsumori, R. Akiyama, T. Kawamoto, K. Mineo, T. Kurata, T. Kuroda","doi":"10.1109/FUSION.1991.218823","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218823","url":null,"abstract":"A test stand for the negative-ion-based NBI (neutral beam injector) for the LHD, currently under construction, has neutral beam capabilities of 2.5 MW at a beam energy of 125 keV (H/sup 0/)/250 keV (D/sup 0/) and pulse duration of 10 s. Components being developed are as follows: (1) a large and high current negative ion source which is immersed in vacuum and composed of a compact modular ion source; (2) a beam dump to remove high heat flux up to 1.6 kW/cm/sup 2/; (3) a high-pumping-speed (450 m/sup 3//s) cryopump; (4) a 250-kV power supply system using a GTO (gate turn-off thyristor); and (5) a controller system to vary the beam energy within 0.5 s.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124948228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-09-30DOI: 10.1109/FUSION.1991.218722
T. O'connor, L. Grisham, J. Kamperschroer, G. Rossi, T. Stevenson, A. von Halle, M. Williams
A method of analyzing the divergence characteristics of particle beams that utilize a Pierce geometry accelerator is described. The technique combines measurements of gradient grid current and arc current to develop an analytic expression, (perveance function), that could prove beneficial to beam operations. Unlike thermocouple or Doppler measurements of beam divergence, which only indicate the magnitude of the beam angle, the perveance function exhibits bipolar linearity with arc current changes. Additionally, the value of the arc current at which the perveance function equals zero is the operating point for minimum beam divergence. As a result, a single measurement with the perveance function can indicate whether the beam is overfocused or underfocused, and also determine the change in the magnitude and direction of the operating point to achieve optimum focus. This method is superior to present procedures, which tune the source by hunting for the minimum divergence. The perveance function is a relatively simple relationship that can be easily realized in hardware electronics or computer software.<>
{"title":"The perveance function (particle accelerators)","authors":"T. O'connor, L. Grisham, J. Kamperschroer, G. Rossi, T. Stevenson, A. von Halle, M. Williams","doi":"10.1109/FUSION.1991.218722","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218722","url":null,"abstract":"A method of analyzing the divergence characteristics of particle beams that utilize a Pierce geometry accelerator is described. The technique combines measurements of gradient grid current and arc current to develop an analytic expression, (perveance function), that could prove beneficial to beam operations. Unlike thermocouple or Doppler measurements of beam divergence, which only indicate the magnitude of the beam angle, the perveance function exhibits bipolar linearity with arc current changes. Additionally, the value of the arc current at which the perveance function equals zero is the operating point for minimum beam divergence. As a result, a single measurement with the perveance function can indicate whether the beam is overfocused or underfocused, and also determine the change in the magnitude and direction of the operating point to achieve optimum focus. This method is superior to present procedures, which tune the source by hunting for the minimum divergence. The perveance function is a relatively simple relationship that can be easily realized in hardware electronics or computer software.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123435520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-09-30DOI: 10.1109/FUSION.1991.218821
M. Kuriyama, M. Araki, M. Hanada, T. Inoue, S. Kunieda, M. Matsuoka, M. Mizuno, Y. Ohara, Y. Okumura, H. Oohara, K. Watanabe
A negative-ion-based NBI (neutral-beam injection) system is planned as a key device in the JT-60U (JAERI Tokamak-60 upgrade) experimentation involving current drive and plasma core heating with high density plasmas. The NBI system will inject neutral beams of 500 keV, 10 MW for 10 s from a beamline with two ion sources. The neutral beam will be injected tangentially in the co-direction. Each ion source is a modified volume production-type negative-ion source with cesium vapor. The acceleration current is 22 A with a deuterium beam, and the current density is 13 mA/cm/sup 2/. Operational pressure in the negative-ion generator is less than 0.5 Pa. A three-stage electrostatic acceleration system is adopted as the accelerator. The beamline length between the ion source and the injection port is 24 m. The beamline consists of an ion source tank, neutralizer cells of 10 m in length, an ion dump tank, and a drift duct. Residual ions are deflected by the combined magnetic fields produced by the deflecting coils and the stray field from the tokamak. The two sources are connected to an acceleration power supply of 500 kV/64 A/10 s, while the negative-ion generator power, the extraction voltage, and electron-suppression voltage are fed individually.<>
{"title":"Design of a negative-ion-based NBI system for JT-60U","authors":"M. Kuriyama, M. Araki, M. Hanada, T. Inoue, S. Kunieda, M. Matsuoka, M. Mizuno, Y. Ohara, Y. Okumura, H. Oohara, K. Watanabe","doi":"10.1109/FUSION.1991.218821","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218821","url":null,"abstract":"A negative-ion-based NBI (neutral-beam injection) system is planned as a key device in the JT-60U (JAERI Tokamak-60 upgrade) experimentation involving current drive and plasma core heating with high density plasmas. The NBI system will inject neutral beams of 500 keV, 10 MW for 10 s from a beamline with two ion sources. The neutral beam will be injected tangentially in the co-direction. Each ion source is a modified volume production-type negative-ion source with cesium vapor. The acceleration current is 22 A with a deuterium beam, and the current density is 13 mA/cm/sup 2/. Operational pressure in the negative-ion generator is less than 0.5 Pa. A three-stage electrostatic acceleration system is adopted as the accelerator. The beamline length between the ion source and the injection port is 24 m. The beamline consists of an ion source tank, neutralizer cells of 10 m in length, an ion dump tank, and a drift duct. Residual ions are deflected by the combined magnetic fields produced by the deflecting coils and the stray field from the tokamak. The two sources are connected to an acceleration power supply of 500 kV/64 A/10 s, while the negative-ion generator power, the extraction voltage, and electron-suppression voltage are fed individually.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123793042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-09-30DOI: 10.1109/FUSION.1991.218892
K. Nakamoto, T. Yoshida, S. Mizumaki, K. Yamamoto, K. Nakayama, M. Shimada, Y. Wachi, M. Shibui, T. Uchida, H. Shinohara, H. Takano, S. Ioka, T. Mito, K. Takahata, N. Yanagi, J. Yamamoto, O. Motojima
Two different forced-cooled superconducting coils (TOKI-TF and TOKI-PF) were designed and fabricated to develop field coils for the Large Helical Device (LHD). The conductor used in the coils was the NbTi/Cu cable-in-conduit superconductor (CIC) encased in a SUS316L conduit and cooled with 4.5 K supercritical helium. The TOKI-TF is a helical coil with a field period m=4 wound in ten layers with the CIC conductor of 8 kA at 2.77 T. Its major and minor radii are 0.9 m and 0.25 m, respectively. One of the aims of the TOKI-TF was to demonstrate helical winding of the CIC conductor with good accuracy required for the LHD helical field coil. The TOKI-PF is a ring coil with a radius of 0.71 m, consisting of two double pancakes wound with the conductor of 25.6 kA at 2.76 T. The TOKI-PF was successfully energized at full current and provided useful data on the coil performance under a ramp rate of 2000 A/s and a long dump with a constant of 20 s.<>
{"title":"Design and fabrication of the R&D facility for Large Helical Device","authors":"K. Nakamoto, T. Yoshida, S. Mizumaki, K. Yamamoto, K. Nakayama, M. Shimada, Y. Wachi, M. Shibui, T. Uchida, H. Shinohara, H. Takano, S. Ioka, T. Mito, K. Takahata, N. Yanagi, J. Yamamoto, O. Motojima","doi":"10.1109/FUSION.1991.218892","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218892","url":null,"abstract":"Two different forced-cooled superconducting coils (TOKI-TF and TOKI-PF) were designed and fabricated to develop field coils for the Large Helical Device (LHD). The conductor used in the coils was the NbTi/Cu cable-in-conduit superconductor (CIC) encased in a SUS316L conduit and cooled with 4.5 K supercritical helium. The TOKI-TF is a helical coil with a field period m=4 wound in ten layers with the CIC conductor of 8 kA at 2.77 T. Its major and minor radii are 0.9 m and 0.25 m, respectively. One of the aims of the TOKI-TF was to demonstrate helical winding of the CIC conductor with good accuracy required for the LHD helical field coil. The TOKI-PF is a ring coil with a radius of 0.71 m, consisting of two double pancakes wound with the conductor of 25.6 kA at 2.76 T. The TOKI-PF was successfully energized at full current and provided useful data on the coil performance under a ramp rate of 2000 A/s and a long dump with a constant of 20 s.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122611143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1991-09-30DOI: 10.1109/FUSION.1991.218769
S. Sharafat, F. Najmabadi, I. Sviatoslavsky
The direct integration activities of the ARIES-III reactor study have resulted in a reactor component layout that minimizes the number of vacuum-vessel penetrations and the number of connect/disconnects, and allows divertor target maintenance without affecting other components. A bifurcated divertor pumping duct at the bottom of the machine serves as an access port to the lower divertor plate and also provides adequate room for performing connect/disconnect actions on the inboard and outboard shield modules. The upper divertor-plate piping network is elevated above the inboard shield, which gives access to any in-vessel component. Minor first-wall recoating can be performed in situ using remote-controlled plasma-spray equipment already in service. Access to the vacuum vessel form the top requires lifting the upper two poloidal-field coils with their cryostat and support structure.<>
{"title":"Design layout and maintenance of the ARIES-III tokamak reactor","authors":"S. Sharafat, F. Najmabadi, I. Sviatoslavsky","doi":"10.1109/FUSION.1991.218769","DOIUrl":"https://doi.org/10.1109/FUSION.1991.218769","url":null,"abstract":"The direct integration activities of the ARIES-III reactor study have resulted in a reactor component layout that minimizes the number of vacuum-vessel penetrations and the number of connect/disconnects, and allows divertor target maintenance without affecting other components. A bifurcated divertor pumping duct at the bottom of the machine serves as an access port to the lower divertor plate and also provides adequate room for performing connect/disconnect actions on the inboard and outboard shield modules. The upper divertor-plate piping network is elevated above the inboard shield, which gives access to any in-vessel component. Minor first-wall recoating can be performed in situ using remote-controlled plasma-spray equipment already in service. Access to the vacuum vessel form the top requires lifting the upper two poloidal-field coils with their cryostat and support structure.<<ETX>>","PeriodicalId":318951,"journal":{"name":"[Proceedings] The 14th IEEE/NPSS Symposium Fusion Engineering","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122880663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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