Pub Date : 2008-06-15DOI: 10.1109/PLASMA.2008.4590847
T. Idehara, I. Ogawa, S. Kobayashi, L. Agusu, S. Mitsudo, T. Saito, T. Fujiwara, H. Takahashi
Summary form only given. Recently, medium power, sub-THz gyrotrons were developed for application to DNP-NMR experiment for enhancing the sensitivity of NMR. In FIR FU, 394.6 GHz CW gyrotron FU CW II which is the second gyrotron of Gyrotron FU CW Series has been developed for DNP/NMR at 600 MHz under a collaboration with Institute of Protein Research, Osaka University. The output power and the frequency are 32 W at the CW operation and 394.3 GHz at the second harmonic operation. The width of frequency spectrum is as narrow as 10 kHz. We have already installed the gyrotron on 600 proton NMR device at Osaka University and hope to begin the DNP experiment soon. We will present the operation performance of gyrotron FU CW II.
{"title":"394.6 GHz CW gyrotron FU CW II for DNP/NMR at 600 MHz","authors":"T. Idehara, I. Ogawa, S. Kobayashi, L. Agusu, S. Mitsudo, T. Saito, T. Fujiwara, H. Takahashi","doi":"10.1109/PLASMA.2008.4590847","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590847","url":null,"abstract":"Summary form only given. Recently, medium power, sub-THz gyrotrons were developed for application to DNP-NMR experiment for enhancing the sensitivity of NMR. In FIR FU, 394.6 GHz CW gyrotron FU CW II which is the second gyrotron of Gyrotron FU CW Series has been developed for DNP/NMR at 600 MHz under a collaboration with Institute of Protein Research, Osaka University. The output power and the frequency are 32 W at the CW operation and 394.3 GHz at the second harmonic operation. The width of frequency spectrum is as narrow as 10 kHz. We have already installed the gyrotron on 600 proton NMR device at Osaka University and hope to begin the DNP experiment soon. We will present the operation performance of gyrotron FU CW II.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85640306","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4590633
M. Gallagher, A. Rabinovich, A. Gutsol, A. Fridman
Conversion of liquid hydrocarbon fuels to produce synthesis gas using non-equilibrium gliding discharges is performed using a reverse vortex flow ("tornado") reactor. Part of the integrated system is plasma reformer, which utilizes syngas (CO + H2) for direct use in a solid oxide fuel cell for onboard conversion liquid fuels into electricity. This integrated system can be an advance power generator that can be used in remote areas where only hydrocarbon fuel sources are available and have potential military applications.
{"title":"Liquid fuel conversion using gliding discharge in Tornado for direct use in solid oxide fuel cells","authors":"M. Gallagher, A. Rabinovich, A. Gutsol, A. Fridman","doi":"10.1109/PLASMA.2008.4590633","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590633","url":null,"abstract":"Conversion of liquid hydrocarbon fuels to produce synthesis gas using non-equilibrium gliding discharges is performed using a reverse vortex flow (\"tornado\") reactor. Part of the integrated system is plasma reformer, which utilizes syngas (CO + H2) for direct use in a solid oxide fuel cell for onboard conversion liquid fuels into electricity. This integrated system can be an advance power generator that can be used in remote areas where only hydrocarbon fuel sources are available and have potential military applications.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85947155","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4590673
L. Alberts, M. Kaiser, C. Hunyar, M. Graf, K. Nauenburg, E. Rauchle
Summary form only given. Microwave based surface wave plasma reactors like those relying on the Duo-Plasmaline encounters large success in dielectric coating applications. But they show principal limitation to dielectric materials applications. We attempt here to present a Duo-Plasmaline NG based on the metal antenna SWP. This design would circumvent the dielectric coating limitation. The propagation length of the plasma will be reported as a function of gas pressure, microwave power and bias potential for different atmospheres like argon, nitrogen and oxygen. The plasma homogeneity will be reflected in the coating thickness evolution of a PECVD thin film along the antenna.
{"title":"Application of a MASWP: Duo_Plasmaline next generation","authors":"L. Alberts, M. Kaiser, C. Hunyar, M. Graf, K. Nauenburg, E. Rauchle","doi":"10.1109/PLASMA.2008.4590673","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590673","url":null,"abstract":"Summary form only given. Microwave based surface wave plasma reactors like those relying on the Duo-Plasmaline encounters large success in dielectric coating applications. But they show principal limitation to dielectric materials applications. We attempt here to present a Duo-Plasmaline NG based on the metal antenna SWP. This design would circumvent the dielectric coating limitation. The propagation length of the plasma will be reported as a function of gas pressure, microwave power and bias potential for different atmospheres like argon, nitrogen and oxygen. The plasma homogeneity will be reflected in the coating thickness evolution of a PECVD thin film along the antenna.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77012768","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4591125
K. Arshak, I. Guiney, E. Forde
Summary form only given. In this paper, optical and electrical measurements of a novel multi-electrode dielectric barrier discharge (DBD) plasma system exhibiting active species gain are performed. This gain in species density is accomplished by arranging four electrode pairs vertically and forcing compressed air through their volumes. This forces the filamentary striations together through lateral pressure, thus aiding in the formation of an extremely dense plasma. The multi-electrode system operates in an effective feed-forward mechanism to create a denser plasma than reported previously. By increasing the initial conditions for oxygen metastables and radicals and other reactive species at each electrode pair, the overall density is increased also for successive electrode pairs. Optical measurements are performed by means of a photomultiplier tube with a quartz window (electron tubes module P30232-07) in order to analyse the deep UV region of the spectrum accurately. These are taken at each of the four electrode stages and at the output of the system. The copious quantities of ozone produced in this DBD plasma are evident from focusing in on the 250-260 nm regime and analysing the associated optical emissions. In addition, the electrical measurements from the quad IGBTs acting as the drive circuitry are analysed and drive circuitry is outlined to create as noiseless an environment as possible. Results indicate that the optical emission around the 250 nm mark throughout the system increases thus showing the increase in the concentration of species with this characteristic wavelength from one plasma volume to the next. The output of the system shows a high density of these species, gradually diminishing as diffusion takes over. The need for compressed air is additionally highlighted by the individual DBD striations being clearly visible when it is not applied. This results in little or no species gain as no accelerant exists in the system. This research has enormous potential in industrial applications due to the high concentration of ozone produced coupled with the prospective in-line set-up of the system.
{"title":"Optical and electrical measurements of a novel dielectric barrier discharge system exhibiting species gain","authors":"K. Arshak, I. Guiney, E. Forde","doi":"10.1109/PLASMA.2008.4591125","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4591125","url":null,"abstract":"Summary form only given. In this paper, optical and electrical measurements of a novel multi-electrode dielectric barrier discharge (DBD) plasma system exhibiting active species gain are performed. This gain in species density is accomplished by arranging four electrode pairs vertically and forcing compressed air through their volumes. This forces the filamentary striations together through lateral pressure, thus aiding in the formation of an extremely dense plasma. The multi-electrode system operates in an effective feed-forward mechanism to create a denser plasma than reported previously. By increasing the initial conditions for oxygen metastables and radicals and other reactive species at each electrode pair, the overall density is increased also for successive electrode pairs. Optical measurements are performed by means of a photomultiplier tube with a quartz window (electron tubes module P30232-07) in order to analyse the deep UV region of the spectrum accurately. These are taken at each of the four electrode stages and at the output of the system. The copious quantities of ozone produced in this DBD plasma are evident from focusing in on the 250-260 nm regime and analysing the associated optical emissions. In addition, the electrical measurements from the quad IGBTs acting as the drive circuitry are analysed and drive circuitry is outlined to create as noiseless an environment as possible. Results indicate that the optical emission around the 250 nm mark throughout the system increases thus showing the increase in the concentration of species with this characteristic wavelength from one plasma volume to the next. The output of the system shows a high density of these species, gradually diminishing as diffusion takes over. The need for compressed air is additionally highlighted by the individual DBD striations being clearly visible when it is not applied. This results in little or no species gain as no accelerant exists in the system. This research has enormous potential in industrial applications due to the high concentration of ozone produced coupled with the prospective in-line set-up of the system.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78232948","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4590950
R. Vidmar, K. Stalder
A 100-keV electron beam is used to ionize air within a test cell in which the pressure is varied from 1 mT to 600 T. In these experiments, the electron beam is operated with a single pulse of 10 -ms duration at a current of 5.6 mA. The beam in injected into the tank through a 12.7-mum aluminum foil window that separates the electron source from the test cell. Byproducts of volumetric ionization and dissociation include plasma electrons, ozone produced by the rapid reaction of atomic oxygen with oxygen in the air, and excitation of the N2 Second Positive line at 337.1 nm. The N2 emissions were observed 2 cm from the foil window using a fiber optic system. Ozone was detected by optical absorption at 255 nm and electrons were detected by an rf phase measurement system operating at 10 GHz. The ozone and rf measurements were made on the test-cell midplane, 25 cm from the foil window. An air chemistry code1 is used to estimate ozone production and rf phase shift as a function of volumetric ionization rate which was subsequently compared with the experimental data. These measurements are discussed as well as an estimate of the power required to generate and sustain the plasma density.
在这些实验中，电子束在5.6毫安的电流下以10毫秒持续时间的单脉冲操作，电子束被用于电离压力从1毫安到600毫安的测试单元内的空气。电子束通过一个12.7微米的铝箔窗注入罐中，该窗将电子源与测试单元分开。体积电离和解离的副产物包括等离子体电子、原子氧与空气中的氧快速反应产生的臭氧以及在337.1 nm处激发N2 Second Positive线。利用光纤系统在距箔窗2cm处观察N2发射。采用255 nm光吸收检测臭氧，10 GHz射频相位测量系统检测电子。臭氧和射频测量是在测试电池背板上进行的，距离箔窗25厘米。使用空气化学代码1来估计臭氧产生和射频相移作为体积电离率的函数，随后将其与实验数据进行比较。讨论了这些测量以及产生和维持等离子体密度所需功率的估计。
{"title":"Electron-beam generated air plasma: Ozone and electron density measurements","authors":"R. Vidmar, K. Stalder","doi":"10.1109/PLASMA.2008.4590950","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590950","url":null,"abstract":"A 100-keV electron beam is used to ionize air within a test cell in which the pressure is varied from 1 mT to 600 T. In these experiments, the electron beam is operated with a single pulse of 10 -ms duration at a current of 5.6 mA. The beam in injected into the tank through a 12.7-mum aluminum foil window that separates the electron source from the test cell. Byproducts of volumetric ionization and dissociation include plasma electrons, ozone produced by the rapid reaction of atomic oxygen with oxygen in the air, and excitation of the N2 Second Positive line at 337.1 nm. The N2 emissions were observed 2 cm from the foil window using a fiber optic system. Ozone was detected by optical absorption at 255 nm and electrons were detected by an rf phase measurement system operating at 10 GHz. The ozone and rf measurements were made on the test-cell midplane, 25 cm from the foil window. An air chemistry code1 is used to estimate ozone production and rf phase shift as a function of volumetric ionization rate which was subsequently compared with the experimental data. These measurements are discussed as well as an estimate of the power required to generate and sustain the plasma density.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72817676","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4591121
K. Hill, M. Bitter, S. Scott, A. Ince-Cushman, J. Rice, M. Reinke, P. Beiersdorfer, M. Gu, S.G. Lee, C. Broennimann, E. Eikenberry
In this paper, a new spatially resolving X-ray crystal spectrometer (XCS) capable of measuring continuous spatial profiles of high resolution spectra (lambda/dlambda > 6000) of He-like and H-like Ar Kalpha lines has been installed on the Alcator C-Mod tokamak. The spectrometer has an improved measurements on ion temperature (Ti), intrinsic rotation-velocity profiles (vphi) with excellent spatial (~1 cm) and temporal resolution, and on the atomic physics of highly charged ions.The data analysis techniques, (Ti) and (vphi) profile results, analysis of background resulting from fusion neutrons, and predictions of performance on the international tokamak ITER and other tokamaks is presented.
本文在Alcator C-Mod托卡马克上安装了一种新的空间分辨x射线晶体光谱仪(XCS)，该光谱仪能够测量类he和类h Ar Kalpha线的连续高分辨光谱(λ /dlambda > 6000)。该光谱仪改进了离子温度(Ti)的测量，具有优异的空间(~1 cm)和时间分辨率的本征旋转速度谱(vphi)，以及高电荷离子的原子物理特性。介绍了数据分析技术、(Ti)和(vphi)剖面结果、聚变中子产生的背景分析以及在国际托卡马克ITER和其他托卡马克上的性能预测。
{"title":"Ion-temperature and rotation-velocity profile measurements from a spatially resolving x-ray crystal spectrometer on the alcator C-Mod tokamak","authors":"K. Hill, M. Bitter, S. Scott, A. Ince-Cushman, J. Rice, M. Reinke, P. Beiersdorfer, M. Gu, S.G. Lee, C. Broennimann, E. Eikenberry","doi":"10.1109/PLASMA.2008.4591121","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4591121","url":null,"abstract":"In this paper, a new spatially resolving X-ray crystal spectrometer (XCS) capable of measuring continuous spatial profiles of high resolution spectra (lambda/dlambda > 6000) of He-like and H-like Ar Kalpha lines has been installed on the Alcator C-Mod tokamak. The spectrometer has an improved measurements on ion temperature (Ti), intrinsic rotation-velocity profiles (vphi) with excellent spatial (~1 cm) and temporal resolution, and on the atomic physics of highly charged ions.The data analysis techniques, (Ti) and (vphi) profile results, analysis of background resulting from fusion neutrons, and predictions of performance on the international tokamak ITER and other tokamaks is presented.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72919395","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4591115
A. Surov, V. Spodobin, R. Ovchinnikov, S. A. Kuschev, S. Lukyanov, V. Shiryaev, V. Kuznetsov
At a modern level of industrial development the problem of waste processing has assumed a new significance. New laws and more strict standards are imposed every year in the majority of countries. Large industrial companies and municipal structures in this situation are forced to invest significant founds in waste destruction. Each year the creation of environmentally friendly technologies of waste treatment gets the increasing investment appeal. Plasmachemical technology is the most perspective technology of waste recycling. It is based on high-temperature plasmachemical action and complete decomposition of utilized products by means of arc plasma with useful product (synthesis-gas) production, which is a mixture of hydrogen and carbon oxide and is a valuable power raw material. One of the requirements to electric arc plasma generators working in plasmachemical installations is a long lifetime of continuous operation. First of all time of continuous operation of the plasma generator is determined by lifetime of its electrode unit. Now it is perspective to use steam as a plasmaforming environment. The idea of steam use as a working body is often put forward as one of alternatives to air plasma. Water has high heat of steam formation successfully combining properties of plasmaforming substance and cooling heat-carrier. Steam is an ideal plasmaforming environment. It is ecological, explosion-proof and available working substance favorably influencing on the ecological conditions in examined gasification processes.The paper depicts the investigation results carried out at development of plasma generators using steam as a plasmaforming environment. Modern methods of manufacturing of electrode materials allow creation of composite materials of complex composition by introduction of more refractory material in a copper matrix. The noticeable increase in life time and decrease in the specific flow rate (wear) of electrode material gives prospect in the further researches and development of new kinds of materials, that at steam application as a working body creates a wide spectrum of use of these high-voltage plasma generators at gasification and pyrolysis plants.
{"title":"Research of operation features of electrode units of high-voltage plasma generators of alternating current, definition of the criteria influencing the electrode lifetime at plasma generator operation on steam","authors":"A. Surov, V. Spodobin, R. Ovchinnikov, S. A. Kuschev, S. Lukyanov, V. Shiryaev, V. Kuznetsov","doi":"10.1109/PLASMA.2008.4591115","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4591115","url":null,"abstract":"At a modern level of industrial development the problem of waste processing has assumed a new significance. New laws and more strict standards are imposed every year in the majority of countries. Large industrial companies and municipal structures in this situation are forced to invest significant founds in waste destruction. Each year the creation of environmentally friendly technologies of waste treatment gets the increasing investment appeal. Plasmachemical technology is the most perspective technology of waste recycling. It is based on high-temperature plasmachemical action and complete decomposition of utilized products by means of arc plasma with useful product (synthesis-gas) production, which is a mixture of hydrogen and carbon oxide and is a valuable power raw material. One of the requirements to electric arc plasma generators working in plasmachemical installations is a long lifetime of continuous operation. First of all time of continuous operation of the plasma generator is determined by lifetime of its electrode unit. Now it is perspective to use steam as a plasmaforming environment. The idea of steam use as a working body is often put forward as one of alternatives to air plasma. Water has high heat of steam formation successfully combining properties of plasmaforming substance and cooling heat-carrier. Steam is an ideal plasmaforming environment. It is ecological, explosion-proof and available working substance favorably influencing on the ecological conditions in examined gasification processes.The paper depicts the investigation results carried out at development of plasma generators using steam as a plasmaforming environment. Modern methods of manufacturing of electrode materials allow creation of composite materials of complex composition by introduction of more refractory material in a copper matrix. The noticeable increase in life time and decrease in the specific flow rate (wear) of electrode material gives prospect in the further researches and development of new kinds of materials, that at steam application as a working body creates a wide spectrum of use of these high-voltage plasma generators at gasification and pyrolysis plants.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80317178","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4590859
S. Kim, H.R. Yang, M. Cho, W. Namkung, S. Jang, S.J. Kwon, Y. Son, S. Park, J. Oh
An intense L-band electron linear accelerator is under construction at CESC (Cheorwon Electron-beam Service Center) for industrial applications. It is capable of producing 10-MeV electron beams with 30-kW average beam power. For high-power capability, we adopted 1.3 GHz, and the RF source is a 25-MW pulsed klystron with 60-kW average RF output power. The PFN-type modulator and the matched transformer provide 264-kV beam voltage with 230-A beam current to the klystron. The RF pulse length is 7 mus, and the repetition rate is 350 Hz. The thermionic E-gun generates 80-kV electron beams with pulsed 1.6 A. The pre-buncher, a single standing-wave cavity, is used before the bunching section, which is built-in with the regular accelerating section. The accelerating structure is a disk-loaded waveguide with a constant-impedance operated in the 2pi/3-mode. It is to be operated under the fully beam-loaded condition, where the beam power is maximum. The electron beams are accelerated within 6 mus since the traveling-wave filling time of the accelerating structure is almost 0.8 mus. In this paper, we present details of the accelerator system and commissioning results.
{"title":"Commissioning of L-band intense electron linac for industrial applications","authors":"S. Kim, H.R. Yang, M. Cho, W. Namkung, S. Jang, S.J. Kwon, Y. Son, S. Park, J. Oh","doi":"10.1109/PLASMA.2008.4590859","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590859","url":null,"abstract":"An intense L-band electron linear accelerator is under construction at CESC (Cheorwon Electron-beam Service Center) for industrial applications. It is capable of producing 10-MeV electron beams with 30-kW average beam power. For high-power capability, we adopted 1.3 GHz, and the RF source is a 25-MW pulsed klystron with 60-kW average RF output power. The PFN-type modulator and the matched transformer provide 264-kV beam voltage with 230-A beam current to the klystron. The RF pulse length is 7 mus, and the repetition rate is 350 Hz. The thermionic E-gun generates 80-kV electron beams with pulsed 1.6 A. The pre-buncher, a single standing-wave cavity, is used before the bunching section, which is built-in with the regular accelerating section. The accelerating structure is a disk-loaded waveguide with a constant-impedance operated in the 2pi/3-mode. It is to be operated under the fully beam-loaded condition, where the beam power is maximum. The electron beams are accelerated within 6 mus since the traveling-wave filling time of the accelerating structure is almost 0.8 mus. In this paper, we present details of the accelerator system and commissioning results.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81752629","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4590854
S. Vickers
Summary form only given. The Tom Martin (TM) radiographic diode comprises of a cathode ball mounted on a stalk, separated by vacuum from a flat plate metal anode target. A 2D model of this configuration, as fielded on AWE pulsed power machines, has been created using the particle in cell (PiC) code, large scale plasma (LSP). Predicted outputs have been compared to measured diagnostics in the voltage range of 3 to 6.5 MV. Modelling the cathode ball as a space charge limited source of electrons, qualitative agreement between the predicted and measured impedance histories is found. The model output is shown to be highly dependent on the size of the cathode emission region, with a range in the predicted diode impedance of 100 Omega. Coupled with approximate analysis methods and large experimental uncertainties, this dependence results in a range of diode behaviours that are consistent with the measured data. In this model, ion creation and emission from the target surface is neglected based on experimental observations. This assumption is tested against LSP target surface temperature predictions and found to be consistent over the voltage range considered.
只提供摘要形式。Tom Martin (TM)射线照相二极管由一个安装在杆上的阴极球组成，通过真空与平板金属阳极靶分开。这种配置的二维模型，在AWE脉冲功率机器上，已经使用粒子在细胞(PiC)代码，大规模等离子体(LSP)创建。在3至6.5 MV的电压范围内，将预测输出与测量诊断进行了比较。将阴极球建模为空间电荷有限的电子源，发现预测阻抗历史与测量阻抗历史在定性上一致。模型输出显示高度依赖于阴极发射区域的大小，其范围在预测的二极管阻抗100欧米茄。再加上近似分析方法和大的实验不确定性，这种依赖性导致了一系列与测量数据一致的二极管行为。在该模型中，基于实验观测忽略了目标表面离子的产生和发射。该假设针对LSP目标表面温度预测进行了测试，发现在考虑的电压范围内是一致的。
{"title":"Particle in cell simulations of a Tom Martin diode","authors":"S. Vickers","doi":"10.1109/PLASMA.2008.4590854","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590854","url":null,"abstract":"Summary form only given. The Tom Martin (TM) radiographic diode comprises of a cathode ball mounted on a stalk, separated by vacuum from a flat plate metal anode target. A 2D model of this configuration, as fielded on AWE pulsed power machines, has been created using the particle in cell (PiC) code, large scale plasma (LSP). Predicted outputs have been compared to measured diagnostics in the voltage range of 3 to 6.5 MV. Modelling the cathode ball as a space charge limited source of electrons, qualitative agreement between the predicted and measured impedance histories is found. The model output is shown to be highly dependent on the size of the cathode emission region, with a range in the predicted diode impedance of 100 Omega. Coupled with approximate analysis methods and large experimental uncertainties, this dependence results in a range of diode behaviours that are consistent with the measured data. In this model, ion creation and emission from the target surface is neglected based on experimental observations. This assumption is tested against LSP target surface temperature predictions and found to be consistent over the voltage range considered.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82294976","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 : 2008-06-15DOI: 10.1109/PLASMA.2008.4591185
S. Katsuki, N. Tomimaru, T. Sakugawa, H. Akiyama
In this paper a birdcage discharge head with a plane tin cathode and a stainless steel ball anode was fabricated which enables us to access to the plasma easily. A pulsed laser light with a fluence of 1010 W/cm2 was irradiated at a tin cathode surface to deliver tin vapor to the 5 mm electrode gap, where the high voltage was applied. High density hot plasmas were produced by the electromagnetic compression and the ohmic heating owing to the pulsed high current (20 kA, 150 ns) after the gaseous breakdown. The plasma compression process depends on the delay time dt from the laser irradiation to the breakdown because the laser produced vapor expands quickly, resulting in the change of the gas distribution. The EUV emission intensity was maximum when dt was 300 ns, while the emission region was minimum. The breakdown did not occur for dt smaller than 280 ns because the gas density might not be sufficiently large for the breakdown. The time-resolved imaging of the EUV emission using a gated pinhole EUV camera showed that the hot plasma was produced at first near the laser spot at the cathode and migrated toward the anode quickly. The migration of the hot plasma results in the enlargement of EUV emission region, which is unfavorable for a light source. The observation implies two mechanisms for the migration; one is the pressure wave propagation, and, the other is the collisional ionization of tin ions with electrons accelerated by the induced electric field, which is on the order of 1 MV/cm.
{"title":"Time-resolved observation of laser-assisted discharge plasmas for EUV sources","authors":"S. Katsuki, N. Tomimaru, T. Sakugawa, H. Akiyama","doi":"10.1109/PLASMA.2008.4591185","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4591185","url":null,"abstract":"In this paper a birdcage discharge head with a plane tin cathode and a stainless steel ball anode was fabricated which enables us to access to the plasma easily. A pulsed laser light with a fluence of 1010 W/cm2 was irradiated at a tin cathode surface to deliver tin vapor to the 5 mm electrode gap, where the high voltage was applied. High density hot plasmas were produced by the electromagnetic compression and the ohmic heating owing to the pulsed high current (20 kA, 150 ns) after the gaseous breakdown. The plasma compression process depends on the delay time dt from the laser irradiation to the breakdown because the laser produced vapor expands quickly, resulting in the change of the gas distribution. The EUV emission intensity was maximum when dt was 300 ns, while the emission region was minimum. The breakdown did not occur for dt smaller than 280 ns because the gas density might not be sufficiently large for the breakdown. The time-resolved imaging of the EUV emission using a gated pinhole EUV camera showed that the hot plasma was produced at first near the laser spot at the cathode and migrated toward the anode quickly. The migration of the hot plasma results in the enlargement of EUV emission region, which is unfavorable for a light source. The observation implies two mechanisms for the migration; one is the pressure wave propagation, and, the other is the collisional ionization of tin ions with electrons accelerated by the induced electric field, which is on the order of 1 MV/cm.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86933993","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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