Pub Date : 2009-09-01DOI: 10.1080/10519990902957963
A. Alekseev
Electromagnetic forces and possible magnetoelastic buckling caused by interaction with the toroidal magnetic field are analysed for the in-vessel poloidal field coils of the tokamak T-15 upgrade. Analytical expressions for the forces and critical currents have been derived. The analysis shows that the stiffness of the in-vessel coils provides the stability of the coils with sufficient safety margins.
{"title":"Electromagnetic loads and magnetoelastic stability of the in-vessel poloidal field coils of the T-15 upgrade","authors":"A. Alekseev","doi":"10.1080/10519990902957963","DOIUrl":"https://doi.org/10.1080/10519990902957963","url":null,"abstract":"Electromagnetic forces and possible magnetoelastic buckling caused by interaction with the toroidal magnetic field are analysed for the in-vessel poloidal field coils of the tokamak T-15 upgrade. Analytical expressions for the forces and critical currents have been derived. The analysis shows that the stiffness of the in-vessel coils provides the stability of the coils with sufficient safety margins.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"1 1","pages":"201 - 206"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88700939","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 : 2009-06-19DOI: 10.1080/10519990902957955
Z. Trifković, P. Osmokrović
A linearly polarized electromagnetic source wave splits into six traveling wave modes (three of them are right-hand circularly-polarized (RCP) modes and three are left-hand circularly-polarized (LCP) modes) due to the interaction with a suddenly created magnetoplasma medium. When the angular frequency of the source wave is in the low-frequency region, the magnetoplasma supports two whistler wave modes (one is the transmitted RCP and the other is the reflected LCP). It is shown that the efficiency of energy conversion of the LCP whistler wave mode into the magnetic field of the wiggler is nearly of the same order of magnitude as the efficiency of the previously considered energy conversion of the RCP whistler wave mode.
{"title":"Conversion of a left-hand circularly polarized whistler wave into the magnetic energy of a controllable helical wiggler wave","authors":"Z. Trifković, P. Osmokrović","doi":"10.1080/10519990902957955","DOIUrl":"https://doi.org/10.1080/10519990902957955","url":null,"abstract":"A linearly polarized electromagnetic source wave splits into six traveling wave modes (three of them are right-hand circularly-polarized (RCP) modes and three are left-hand circularly-polarized (LCP) modes) due to the interaction with a suddenly created magnetoplasma medium. When the angular frequency of the source wave is in the low-frequency region, the magnetoplasma supports two whistler wave modes (one is the transmitted RCP and the other is the reflected LCP). It is shown that the efficiency of energy conversion of the LCP whistler wave mode into the magnetic field of the wiggler is nearly of the same order of magnitude as the efficiency of the previously considered energy conversion of the RCP whistler wave mode.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"560 1","pages":"215 - 220"},"PeriodicalIF":0.0,"publicationDate":"2009-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85988190","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 : 2009-06-19DOI: 10.1080/10519990902957989
Y. Ding, G. Zhuang, W. J. Wang, J. Yao, X. Q. Zhang, Y. Pan
A new vacuum system is designed and developed on the Joint Texas Experimental tokamak (J-TEXT), which consists of two pumping stations, a Taylor discharge cleaning (TDC) system and gas puffing. With this system, the vacuum vessel of the J-TEXT tokamak can easily reach the vacuum conditions which allow the operation of the machine. The sub-control system of the vacuum pumping systems with the self-protection function is reliable and easy to use. Inside the chamber, the base pressure can be lowered to 6.4×10−6 Pa, and the total leakage and outgassing rates in 12 h is below 1.5×10−8 Pa m3/s. Moreover, the TDC sub-system is used to clean the first facing walls of vacuum chamber to guarantee good wall conditions of the device before each run of the experimental campaign on the J-TEXT tokamak. The basic functions of the vacuum system meet the essential requirements for the present experiments on the J-TEXT tokamak.
在联合德克萨斯实验托卡马克(J-TEXT)上设计并开发了一种新型真空系统，该系统由两个泵站、一个泰勒排放清洗(TDC)系统和充气组成。利用该系统，J-TEXT托卡马克的真空容器可以很容易地达到允许机器运行的真空条件。真空抽气系统的分控制系统具有自我保护功能，可靠，使用方便。腔内可将基压降至6.4×10−6 Pa, 12h总泄漏和放气速率低于1.5×10−8 Pa m3/s。此外，在J-TEXT托卡马克每次运行实验前，采用TDC子系统对真空室的第一面壁面进行清洗，以保证装置壁面条件良好。真空系统的基本功能满足J-TEXT托卡马克实验的基本要求。
{"title":"The vacuum system of the J-TEXT tokamak","authors":"Y. Ding, G. Zhuang, W. J. Wang, J. Yao, X. Q. Zhang, Y. Pan","doi":"10.1080/10519990902957989","DOIUrl":"https://doi.org/10.1080/10519990902957989","url":null,"abstract":"A new vacuum system is designed and developed on the Joint Texas Experimental tokamak (J-TEXT), which consists of two pumping stations, a Taylor discharge cleaning (TDC) system and gas puffing. With this system, the vacuum vessel of the J-TEXT tokamak can easily reach the vacuum conditions which allow the operation of the machine. The sub-control system of the vacuum pumping systems with the self-protection function is reliable and easy to use. Inside the chamber, the base pressure can be lowered to 6.4×10−6 Pa, and the total leakage and outgassing rates in 12 h is below 1.5×10−8 Pa m3/s. Moreover, the TDC sub-system is used to clean the first facing walls of vacuum chamber to guarantee good wall conditions of the device before each run of the experimental campaign on the J-TEXT tokamak. The basic functions of the vacuum system meet the essential requirements for the present experiments on the J-TEXT tokamak.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"29 1","pages":"207 - 214"},"PeriodicalIF":0.0,"publicationDate":"2009-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75576156","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 : 2009-06-19DOI: 10.1080/10519990902957948
M. Stepanenko
This paper presents the analysis of the geometrical components in the evaluation of the spectral resolution of X-ray bent crystal spectrometers. A toroidal Johann–Johansson type spectrometer is suggested and its resolution is estimated. Emphasis is made on the study of asymmetrically cut schemes. Generally used expansion techniques up to second order are added by calculations of the third term where second order becomes zero.
{"title":"A spectral resolution of Johann-type X-ray spectrometers","authors":"M. Stepanenko","doi":"10.1080/10519990902957948","DOIUrl":"https://doi.org/10.1080/10519990902957948","url":null,"abstract":"This paper presents the analysis of the geometrical components in the evaluation of the spectral resolution of X-ray bent crystal spectrometers. A toroidal Johann–Johansson type spectrometer is suggested and its resolution is estimated. Emphasis is made on the study of asymmetrically cut schemes. Generally used expansion techniques up to second order are added by calculations of the third term where second order becomes zero.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"19 1","pages":"191 - 200"},"PeriodicalIF":0.0,"publicationDate":"2009-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84373875","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 : 2009-06-19DOI: 10.1080/10519990902957930
Q. Zou, Y. Li, M. Wang, Y. C. Zhao, L. Zou
Microplasma was produced in argon gas in a scanning electron microscope at near-atmospheric pressure using a multi-wall carbon nanotube (CNT) film as a cathode. It is demonstrated that with the CNT film used as a cathode, the breakdown voltage was much lower than the breakdown voltage when the conventional cathode made of flat metal film was used and the discharge was highly reproducible. These features of the gas discharge are defined by the field emission from the CNT cathode.
{"title":"Generation of microplasma using multiwall carbon nanotubes cathode","authors":"Q. Zou, Y. Li, M. Wang, Y. C. Zhao, L. Zou","doi":"10.1080/10519990902957930","DOIUrl":"https://doi.org/10.1080/10519990902957930","url":null,"abstract":"Microplasma was produced in argon gas in a scanning electron microscope at near-atmospheric pressure using a multi-wall carbon nanotube (CNT) film as a cathode. It is demonstrated that with the CNT film used as a cathode, the breakdown voltage was much lower than the breakdown voltage when the conventional cathode made of flat metal film was used and the discharge was highly reproducible. These features of the gas discharge are defined by the field emission from the CNT cathode.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"44 1","pages":"181 - 190"},"PeriodicalIF":0.0,"publicationDate":"2009-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81398514","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 : 2009-06-19DOI: 10.1080/10519990902957807
Q. Zou, M. Wang, Y. Li, L. Zhou
Synthesis of carbon nanomaterials by pulse microplasma in the chamber of a scanning electron microscope equipped with a special discharge cell is reported. The peak current density of the methane microplasma was higher than 5 kA cm−2, and the pulse width was almost 10 ns. After 5 s operation, there could be observed some carbon nanomaterials deposited on the cathode of the platinum film besides melted spots.
报道了用脉冲微等离子体在装有特殊放电电池的扫描电子显微镜腔内合成碳纳米材料的方法。甲烷微等离子体的峰值电流密度大于5 kA cm−2，脉冲宽度接近10 ns。5 s后，在铂膜的正极上除了熔斑外，还可以观察到一些碳纳米材料的沉积。
{"title":"Fabrication of carbon nanomaterials using pulse microplasma in SEM","authors":"Q. Zou, M. Wang, Y. Li, L. Zhou","doi":"10.1080/10519990902957807","DOIUrl":"https://doi.org/10.1080/10519990902957807","url":null,"abstract":"Synthesis of carbon nanomaterials by pulse microplasma in the chamber of a scanning electron microscope equipped with a special discharge cell is reported. The peak current density of the methane microplasma was higher than 5 kA cm−2, and the pulse width was almost 10 ns. After 5 s operation, there could be observed some carbon nanomaterials deposited on the cathode of the platinum film besides melted spots.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"37 1","pages":"175 - 180"},"PeriodicalIF":0.0,"publicationDate":"2009-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90051128","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 : 2009-05-19DOI: 10.1080/10519990902909444
T. Tokuzawa, A. Ejiri, K. Kawahata, LHD experimental group
In order to measure the internal structure of fluctuation, a broadband frequency-tunable system, which has a fast and stable hopping operation, has been developed in the large helical device. For constructing an accurate heterodyne phase detection system, a single-sideband (SSB) modulation technique is applied. Recently, high performance (SSB) modulators have been available in the wide band frequency range and its sideband rejection is around−20 dB. The frequency multiplier and mixer deformed the signal and the band-pass filter is used effectively to attain high signal-to-noise ratio.
{"title":"Heterodyne detection system of frequency hopping microwave reflectometer for Alfvén eigenmode measurements in LHD","authors":"T. Tokuzawa, A. Ejiri, K. Kawahata, LHD experimental group","doi":"10.1080/10519990902909444","DOIUrl":"https://doi.org/10.1080/10519990902909444","url":null,"abstract":"In order to measure the internal structure of fluctuation, a broadband frequency-tunable system, which has a fast and stable hopping operation, has been developed in the large helical device. For constructing an accurate heterodyne phase detection system, a single-sideband (SSB) modulation technique is applied. Recently, high performance (SSB) modulators have been available in the wide band frequency range and its sideband rejection is around−20 dB. The frequency multiplier and mixer deformed the signal and the band-pass filter is used effectively to attain high signal-to-noise ratio.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"1 1","pages":"126 - 131"},"PeriodicalIF":0.0,"publicationDate":"2009-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82745971","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 : 2009-05-19DOI: 10.1080/10519990902884563
S. Kajita, W. Sakaguchi, N. Ohno
Fiberform nanostructured tungsten is formed on tungsten surface by helium plasma irradiation under a specific condition. It is revealed that the optical reflectivity of tungsten is significantly decreased by the formation of the nanostructure. We present the experimentally obtained necessary condition to form the structure in the linear plasma device NAGDIS-II. We investigate the effects of laser irradiation to the helium-irradiated surface on the optical reflectivity. It is revealed that the sub-ms laser pulse irradiation alleviates the surface roughness and recovers the optical reflectivity. However, when the structure is finer, the recovery rate becomes low, typically less than half; moreover, it decreases with the number of pulses.
{"title":"Formation and mitigation of fiberform nanostructured tungsten by helium and sub-ms laser pulse irradiations","authors":"S. Kajita, W. Sakaguchi, N. Ohno","doi":"10.1080/10519990902884563","DOIUrl":"https://doi.org/10.1080/10519990902884563","url":null,"abstract":"Fiberform nanostructured tungsten is formed on tungsten surface by helium plasma irradiation under a specific condition. It is revealed that the optical reflectivity of tungsten is significantly decreased by the formation of the nanostructure. We present the experimentally obtained necessary condition to form the structure in the linear plasma device NAGDIS-II. We investigate the effects of laser irradiation to the helium-irradiated surface on the optical reflectivity. It is revealed that the sub-ms laser pulse irradiation alleviates the surface roughness and recovers the optical reflectivity. However, when the structure is finer, the recovery rate becomes low, typically less than half; moreover, it decreases with the number of pulses.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"50 1","pages":"165 - 173"},"PeriodicalIF":0.0,"publicationDate":"2009-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73033642","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 : 2009-05-19DOI: 10.1080/10519990902884746
M. Wada, T. Kenmotsu, Y. Matsumoto, M. Nishiura, M. Sasao, K. Tsumori, H. Yamaoka
In fusion experiments, plasma erodes walls of devices containing various elements including carbon. The eroded carbon penetrates into edge plasma and is transported backwards forming the carbon-adsorbed layers on the surfaces of components like mirrors for optical plasma diagnostics. To characterize the carbon-adsorbed layers by measuring energy distribution of particles reflected from the surface, we have used the experimental setup equipped with a magnetic deflection momentum analyzer and the time-of-flight energy analyzer of neutrals. Ion beams in the energy range 1–2 keV irradiated the samples of Mo and W with carbon deposition on them that were prepared in separate plasma chambers. The beams produced ions and neutrals with characteristic emission angle and energy distribution depending upon conditions of the sample surfaces. Experimental results are compared with the numerical calculation model ACAT (Atomic Collisions in Amorphous Targets) and the evaluations on how the structure of deposition layers may affect the particle reflection on solid surfaces were made.
在核聚变实验中，等离子体侵蚀含有碳等多种元素的器件壁。被侵蚀的碳渗透到边缘等离子体中，并向后运输，形成光学等离子体诊断用反射镜等组件表面的碳吸附层。为了通过测量从表面反射的粒子的能量分布来表征碳吸附层，我们使用了配备磁偏转动量分析仪和中性物飞行时间能量分析仪的实验装置。能量范围为1 ~ 2kev的离子束辐照分别在等离子体室中制备的Mo和W表面有碳沉积的样品。光束产生的离子和中性离子具有特征发射角和能量分布，这取决于样品表面的条件。将实验结果与数值计算模型ACAT (Atomic Collisions in Amorphous Targets)进行了比较，评价了沉积层的结构对颗粒在固体表面反射的影响。
{"title":"Low-energy particle interaction with plasma-irradiated metal surfaces","authors":"M. Wada, T. Kenmotsu, Y. Matsumoto, M. Nishiura, M. Sasao, K. Tsumori, H. Yamaoka","doi":"10.1080/10519990902884746","DOIUrl":"https://doi.org/10.1080/10519990902884746","url":null,"abstract":"In fusion experiments, plasma erodes walls of devices containing various elements including carbon. The eroded carbon penetrates into edge plasma and is transported backwards forming the carbon-adsorbed layers on the surfaces of components like mirrors for optical plasma diagnostics. To characterize the carbon-adsorbed layers by measuring energy distribution of particles reflected from the surface, we have used the experimental setup equipped with a magnetic deflection momentum analyzer and the time-of-flight energy analyzer of neutrals. Ion beams in the energy range 1–2 keV irradiated the samples of Mo and W with carbon deposition on them that were prepared in separate plasma chambers. The beams produced ions and neutrals with characteristic emission angle and energy distribution depending upon conditions of the sample surfaces. Experimental results are compared with the numerical calculation model ACAT (Atomic Collisions in Amorphous Targets) and the evaluations on how the structure of deposition layers may affect the particle reflection on solid surfaces were made.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"204 1","pages":"132 - 143"},"PeriodicalIF":0.0,"publicationDate":"2009-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76573739","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 : 2009-05-19DOI: 10.1080/10519990902903595
V. Voitsenya, A. F. Bardamid, A. Belyaeva, V. N. Bondarenko, A. Galuza, V. Konovalov, I. Ryzhkov, A. Savchenko, A. N. Shapoval, A. F. Shtan, S. I. Solodovchenko, K. Yakimov
In-vessel mirrors are necessary for optical diagnostics of plasmas in next-step fusion devices. These mirrors will be under the influence of the harsh fusion environment, and in these conditions the mirror material should perform its functions. This article describes experiments that have been carried out to evaluate the prospect of amorphous mirrors retaining their optical characteristics under the impact of deuterium or argon plasma ions of different energy. The experiments were undertaken with the use of mirror samples prepared from amorphous alloys Vitreloy-1 and Vitreloy-4. The data reported demonstrate the principal ability of mirrors made of amorphous materials to preserve the initial optical quality in the process of long-term sputtering, and should be considered as proof of the possibility of using amorphous metal mirrors in the erosion-dominated zone of a fusion reactor.
{"title":"Modification of optical characteristics of metallic amorphous mirrors under ion bombardment","authors":"V. Voitsenya, A. F. Bardamid, A. Belyaeva, V. N. Bondarenko, A. Galuza, V. Konovalov, I. Ryzhkov, A. Savchenko, A. N. Shapoval, A. F. Shtan, S. I. Solodovchenko, K. Yakimov","doi":"10.1080/10519990902903595","DOIUrl":"https://doi.org/10.1080/10519990902903595","url":null,"abstract":"In-vessel mirrors are necessary for optical diagnostics of plasmas in next-step fusion devices. These mirrors will be under the influence of the harsh fusion environment, and in these conditions the mirror material should perform its functions. This article describes experiments that have been carried out to evaluate the prospect of amorphous mirrors retaining their optical characteristics under the impact of deuterium or argon plasma ions of different energy. The experiments were undertaken with the use of mirror samples prepared from amorphous alloys Vitreloy-1 and Vitreloy-4. The data reported demonstrate the principal ability of mirrors made of amorphous materials to preserve the initial optical quality in the process of long-term sputtering, and should be considered as proof of the possibility of using amorphous metal mirrors in the erosion-dominated zone of a fusion reactor.","PeriodicalId":54600,"journal":{"name":"Plasma Devices and Operations","volume":"101 1","pages":"144 - 154"},"PeriodicalIF":0.0,"publicationDate":"2009-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80447892","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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