Instrumentation for NBI SST-1 cooling water system

International Nuclear Information System (INIS)

Qureshi, Karishma; Patel, Paresh; Jana, M.R.

2015-01-01

Neutral Beam Injector (NBI) System is one of the heating systems for Steady state Superconducting Tokamak (SST-1). It is capable of generating a neutral hydrogen beam of power 0.5 MW at 30 kV. NBI system consists of following sub-systems: Ion source, Neutralizer, Deflection Magnet and Magnet Liner (ML), Ion Dump (ID), V-Target (VT), Pre Duct Scraper (PDS), Beam Transmission Duct (BTD) and Shine Through (ST). For better heat removal management purpose all the above sub-systems shall be equipped with Heat Transfer Elements (THE). During beam operation these sub-systems gets heated due to the received heat load which requires to be removed by efficient supplying water. The cooling water system along with the other systems (External Vacuum System, Gas Feed System, Cryogenics System, etc.) will be controlled by NBI Programmable Logic Control (PLC). In this paper instrumentation and its related design for cooling water system is discussed. The work involves flow control valves, transmitters (pressure, temperature and water flow), pH and conductivity meter signals and its interface with the NBI PLC. All the analog input, analog output, digital input and digital output signals from the cooling water system will be isolated and then fed to the NBI PLC. Graphical Users Interface (GUI) needed in the Wonderware SCADA for the cooling water system shall also be discussed. (author)

Shielding of the NBI boxes against W7-X magnetic stray fields

Energy Technology Data Exchange (ETDEWEB)

Kick, Manfred [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany)], E-mail: Kick@arcor.de; Sielanko, Juliusz [Maria Curie Sklodowska University, Pl. M. C. Sklodowskie 1, 20-031 Lublin (Poland); Heinemann, Bernd; Riedl, Rudolf; Speth, Eckehart; Staebler, Albrecht [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching (Germany)

2009-06-15

Neutral Beam Injection (NBI), besides ECRH, is foreseen as one of the main heating devices at the W7-X stellarator currently under construction at IPP Greifswald, Germany. In a final stage 20 MW of NBI heating power will be installed generated by two NBI boxes of the ASDEX Upgrade (AUG) type. Since magnetic fields generally affect the trajectories of charged particles, essentially all the NBI boxes - including ion sources, acceleration sections, neutralisers and deflection magnets - must be shielded against the stray fields of W7-X. In the magnetic stray fields of W7-X there exist significant radial and toroidal components whereas at tokamaks the vertical components are dominant. The power loads on the ion dump and the protecting structures of the deflecting magnets and the beam lines caused by residual beam ions, therefore, will be strongly different. Thus the shielding concept of AUG cannot simply be taken over, but must be carefully redesigned in order to remain below the critical power limits. New modelling calculations of the magnetic shielding, the ion trajectories and the resulting power loads have been carried out for the 'high iota' and 'low shear' experimental scenarios of W7-X. The fields taken for these calculations are modelled by averaging the calculated W7-X stray fields on the one hand, and by fields generated by two-hypothetical-planar coils perpendicular to the x-y plane, on the other hand. The shielding concept for W7-X mainly consist of iron plates in the outer side regions of the boxes and as little magnetic material as possible inside the boxes.

Ion source development for a photoneutralization based NBI system for fusion reactors

Energy Technology Data Exchange (ETDEWEB)

Simonin, A.; Esch, H. P. L. de; Garibaldi, P.; Grand, C.; Bechu, S.; Bès, A.; Lacoste, A. [CEA-Cadarache, IRFM, F-13108 St. Paul-lez-Durance (France); LPSC, Grenoble-Alpes University, F-38026 Grenoble France (France)

2015-04-08

The next step after ITER is to demonstrate the viability and generation of electricity by a future fusion reactor (DEMO). The specifications required to operate an NBI system on DEMO are very demanding. The system has to provide a very high level of power and energy, ~100MW of D° beam at 1MeV, including high wall-plug efficiency (η > 60%). For this purpose, a new injector concept, called Siphore, is under investigation between CEA and French universities. Siphore is based on the stripping of the accelerated negative ions by photo-detachment provided by several Fabry-Perot cavities (3.5MW of light power per cavity) implemented along the D{sup −} beam. The beamline is designed to be tall and narrow in order that the photon flux overlaps the entire negative ion beam. The paper will describe the present R and D at CEA which addresses the development of an ion source and pre-accelerator prototypes for Siphore, the main goal being to produce an intense negative ion beam sheet. The negative ion source Cybele is based on a magnetized plasma column where hot electrons are emitted from the source center. Parametric studies of the source are performed using Langmuir probes in order to characterize the plasma and to compare with numerical models being developed in French universities.

Ion source development for a photoneutralization based NBI system for fusion reactors

International Nuclear Information System (INIS)

Simonin, A.; Esch, H. P. L. de; Garibaldi, P.; Grand, C.; Bechu, S.; Bès, A.; Lacoste, A.

2015-01-01

The next step after ITER is to demonstrate the viability and generation of electricity by a future fusion reactor (DEMO). The specifications required to operate an NBI system on DEMO are very demanding. The system has to provide a very high level of power and energy, ~100MW of D° beam at 1MeV, including high wall-plug efficiency (η > 60%). For this purpose, a new injector concept, called Siphore, is under investigation between CEA and French universities. Siphore is based on the stripping of the accelerated negative ions by photo-detachment provided by several Fabry-Perot cavities (3.5MW of light power per cavity) implemented along the D − beam. The beamline is designed to be tall and narrow in order that the photon flux overlaps the entire negative ion beam. The paper will describe the present R and D at CEA which addresses the development of an ion source and pre-accelerator prototypes for Siphore, the main goal being to produce an intense negative ion beam sheet. The negative ion source Cybele is based on a magnetized plasma column where hot electrons are emitted from the source center. Parametric studies of the source are performed using Langmuir probes in order to characterize the plasma and to compare with numerical models being developed in French universities

Optimization of the plasma parameters for the high current and uniform large-scale pulse arc ion source of the VEST-NBI system

International Nuclear Information System (INIS)

Jung, Bongki; Park, Min; Heo, Sung Ryul; Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul

2016-01-01

Highlights: • High power magnetic bucket-type arc plasma source for the VEST NBI system is developed with modifications based on the prototype plasma source for KSTAR. • Plasma parameters in pulse duration are measured to characterize the plasma source. • High plasma density and good uniformity is achieved at the low operating pressure below 1 Pa. • Required ion beam current density is confirmed by analysis of plasma parameters and results of a particle balance model. - Abstract: A large-scale hydrogen arc plasma source was developed at the Korea Atomic Energy Research Institute for a high power pulsed NBI system of VEST which is a compact spherical tokamak at Seoul national university. One of the research target of VEST is to study innovative tokamak operating scenarios. For this purpose, high current density and uniform large-scale pulse plasma source is required to satisfy the target ion beam power efficiently. Therefore, optimizing the plasma parameters of the ion source such as the electron density, temperature, and plasma uniformity is conducted by changing the operating conditions of the plasma source. Furthermore, ion species of the hydrogen plasma source are analyzed using a particle balance model to increase the monatomic fraction which is another essential parameter for increasing the ion beam current density. Conclusively, efficient operating conditions are presented from the results of the optimized plasma parameters and the extractable ion beam current is calculated.

Evaluation of power transfer efficiency for a high power inductively coupled radio-frequency hydrogen ion source

Science.gov (United States)

Jain, P.; Recchia, M.; Cavenago, M.; Fantz, U.; Gaio, E.; Kraus, W.; Maistrello, A.; Veltri, P.

2018-04-01

Neutral beam injection (NBI) for plasma heating and current drive is necessary for International Thermonuclear Experimental reactor (ITER) tokamak. Due to its various advantages, a radio frequency (RF) driven plasma source type was selected as a reference ion source for the ITER heating NBI. The ITER relevant RF negative ion sources are inductively coupled (IC) devices whose operational working frequency has been chosen to be 1 MHz and are characterized by high RF power density (˜9.4 W cm-3) and low operational pressure (around 0.3 Pa). The RF field is produced by a coil in a cylindrical chamber leading to a plasma generation followed by its expansion inside the chamber. This paper recalls different concepts based on which a methodology is developed to evaluate the efficiency of the RF power transfer to hydrogen plasma. This efficiency is then analyzed as a function of the working frequency and in dependence of other operating source and plasma parameters. The study is applied to a high power IC RF hydrogen ion source which is similar to one simplified driver of the ELISE source (half the size of the ITER NBI source).

Design of a -1 MV dc UHV power supply for ITER NBI

Science.gov (United States)

Watanabe, K.; Yamamoto, M.; Takemoto, J.; Yamashita, Y.; Dairaku, M.; Kashiwagi, M.; Taniguchi, M.; Tobari, H.; Umeda, N.; Sakamoto, K.; Inoue, T.

2009-05-01

Procurement of a dc -1 MV power supply system for the ITER neutral beam injector (NBI) is shared by Japan and the EU. The Japan Atomic Energy Agency as the Japan Domestic Agency (JADA) for ITER contributes to the procurement of dc -1 MV ultra-high voltage (UHV) components such as a dc -1 MV generator, a transmission line and a -1 MV insulating transformer for the ITER NBI power supply. The inverter frequency of 150 Hz in the -1 MV power supply and major circuit parameters have been proposed and adopted in the ITER NBI. The dc UHV insulation has been carefully designed since dc long pulse insulation is quite different from conventional ac insulation or dc short pulse systems. A multi-layer insulation structure of the transformer for a long pulse up to 3600 s has been designed with electric field simulation. Based on the simulation the overall dimensions of the dc UHV components have been finalized. A surge energy suppression system is also essential to protect the accelerator from electric breakdowns. The JADA contributes to provide an effective surge suppression system composed of core snubbers and resistors. Input energy into the accelerator from the power supply can be reduced to about 20 J, which satisfies the design criteria of 50 J in total in the case of breakdown at -1 MV.

Recent progress of high-power negative ion beam development for fusion plasma heating

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Kazuhiro; Akino, Noboru; Aoyagi, Tetsuo [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; and others

1997-03-01

A negative-ion-based neutral beam injector (N-NBI) has been constructed for JT-60U. The N-NBI is designed to inject 500 keV, 10 MW neutral beams using two ion sources, each producing a 500 keV, 22 A D{sup -} ion beam. Beam acceleration test started in July, 1995 using one ion source. In the preliminary experiment, D{sup -} ion beam of 13.5 A has been successfully accelerated with an energy of 400 keV (5.4 MW) for 0.12 s at an operating pressure of 0.22 Pa. This is the highest D{sup -} beam current and power in the world. Co-extracted electron current was effectively suppressed to the ratio of Ie/I{sub D}- <1. The highest energy beam of 460 keV, 2.4 A, 0.44 s has also been obtained. Neutral beam injection starts in March, 1996 using two ion sources. To realize 1 MeV class NBI system for ITER (International Thermonuclear Experimental Reactor), demonstration of ampere class negative ion beam acceleration up to 1 MeV is an important mile stone. To achieve the mile stone, a high energy test facility called MeV Test Facility (MTF) was constructed. The system consists of a 1 MV, 1 A acceleration power supply and a 100 kW power supply system for negative ion production. Up to now, an H{sup -} ion beam was accelerated up to the energy of 805 keV with an acceleration drain current of 150 mA for 1 s in a five stage electrostatic multi-aperture accelerator. (author)

Asymmetric Distributions of Energetic Circulating Ions and Sawtooth Control using ICCD and Unbalanced NBI

International Nuclear Information System (INIS)

Graves, J. P.

2007-01-01

There is little doubt that various auxiliary heating systems are successfully and routinely controlling sawteeth. There is however some room for improving our understanding of the mechanisms that influence these important changes to the discharges. A mechanism that appears to be common across ECCS, ICCD and unbalanced NBI discharges involves the effect of the q = 1 localised current drive perturbation on resistive diffusion during the sawtooth ramp. Nevertheless, it is important to look for explanations for sawtooth control which may exist in ion based auxiliary systems, but may differ or not exist in electron auxiliary means of sawtooth control. The reason for this is that monster sawteeth, initially lengthened by trapped energetic ions, have up to the present day only been controlled using ICCD, while in ITER the primary method for sawtooth control could be ECCD. A mechanism based on the finite orbit width of parallel asymmetric energetic circulating particles is only non-negligible for ion based auxiliary systems. The present contribution examines the relevance of the latter in sawtooth control experiments, such as those using ICCD and NBI at JET, by looking carefully at the role of circulating ions close to the trapped boundary. At such pitch angles the orbit width is largest, and the parallel asymmetry of the distribution function has the greatest influence. (Author)

Simulation study of energetic ion distribution during combined NBI and ICRF heating in LHD

International Nuclear Information System (INIS)

Murakami, S.; Fukuyama, A.; Kasilov, V.

2006-01-01

In the LHD, significant performances of ICRF heating (fundamental, minority heating regime) have been demonstrated and up to 500keV of energetic tail ions have been observed by fast neutral particle analysis (NPA). These measured results indicate a good property of energetic ion confinement in helical systems. From the 9th campaign of LHD experiment (FY2005) a new perpendicular NBI heating system (P<3MW) has been installed and an effective heating of perpendicularly injected beam ions by the higher harmonics ICRF heating is expected. ICRF heating generates highly energetic tail ions, which drift around the torus for a long time (typically on a collisional time scale). Thus, the behavior of these energetic ions is strongly affected by the characteristics of the drift motions, which depend on the magnetic field configuration. In particular, in a three-dimensional (3D) magnetic configuration, complicated drift motions of trapped particles would play an important role in the confinement of the energetic ions and the ICRF heating process. Therefore a global simulation of ICRF heating is necessary for the accurate modeling of the plasma heating process in a 3D magnetic configuration. In this paper we study the energetic ion distribution during combined NBI and 2nd harmonics ICRF heating in LHD using two global simulation codes: a full wave field solver TASK/WK and a drift kinetic equation solver GNET. GNET solves a linearized drift kinetic equation for energetic ions including complicated behavior of trapped particles in 5-D phase space. TASK/WM solves Maxwell's equation for RF wave electric field with complex frequency as a boundary value problem in the 3D magnetic configuration. (author)

Exit points, on plasma, of lost fast ions during NBI in TJ-II; Puntos de salida en el plasma de los iones rapidos durante NBI en el TJ-II

Energy Technology Data Exchange (ETDEWEB)

Guasp, J.

1995-07-01

The distribution of the exit points, on plasma border, for the lost fast ions during tangential balanced NBI in TJ-II helical axis Stellarator is theoretically analysed, as well for direct as for delayed losses. The link between, the position of those exit points and the corresponding at birth, orbits and drifts is analysed also. It is shown that such relation is rather independent of beam energy and plasma density and is mainly related to the magnetic configuration characteristics. This study is a needed intermediate step to the analysis of impacts of those ions on the vacuum vessel of TJ-II. (Author) 2 refs.

Exit points, on plasma, of lost fast ions during NBI in TJ-II

International Nuclear Information System (INIS)

Guasp, J.

1995-09-01

The distribution of the exit points, on plasma border, for the lost fast ions during tangential balanced NBI in TJ-II helical axis Stellarator is theoretically analysed, as well for direct as for delayed losses. The link between the position of those exit points and the corresponding at birth, orbits and drifts is analysed also, it is shown that such relation is rather independent of beam energy and plasma density and is mainly related to the magnetic configuration characteristics. This study is a needed intermediate step to the analysis of impacts of those ions on the vacuum vessel of TJ-II

Conceptual design of cesium removal device for ITER NBI maintenance

Energy Technology Data Exchange (ETDEWEB)

Oka, Kiyoshi; Shibanuma, Kiyoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2003-03-01

Cesium is required in order to generate a stable negative ion of hydrogen in an ion source of the neutral beam injector (NBI), which is one of the plasma-heating devices for International Thermonuclear Experimental Reactor (ITER). After long time operation of the NBI, the cesium deposits to the insulators supporting the electrode. Due to the deterioration of the insulation resistance, the continuous operation of the NBI will be difficult. In addition, the NBI device is activated by neutrons from D-T plasma, so that periodic removal and cleaning of the cesium on the insulators by remove handling is required. A study of the cesium removal scenario and the device is therefore required considering remote handling. In this report, a cesium removal procedure and conceptual design of the cesium removal device using laser ablation technique are studied, and the feasibility of the laser ablation method is shown. (author)

Heavy ion beam probe investigations of plasma potential in ECRH and NBI in the TJ-II stellarator

International Nuclear Information System (INIS)

Melnikov, A.V.; Eliseev, L.; Perfilov, S.V.; Chmyga, A.A.; Dreval, N.; Khrebtov, S.M.; Komarov, A.D.; Kozachok, A.S.; Krupnik, L.; Alonso, A.; Pablos, J.L. de; Cappa, A.; Fernandez, A.; Fuentes, C.; Hidalgo, C.; Liniers, M.; Pedrosa, M.A.

2005-01-01

Direct measurements of electric potential and its fluctuations are of a primary importance in magnetic confinement systems. The Heavy Ion Beam Probe (HIBP) diagnostic is used in TJ-2 stellarator to study directly plasma electric potential profiles with spatial (up to 1cm) and temporal (up to 10 ∝s) resolution. The singly charged heavy ions Cs + with energies up to 125 keV are used to probe the plasma column from the edge to the core. Both ECRH and NBI heated plasmas (P ECRH = 200 - 400kW, P NBI = 400kW, E NBI = 28 kV) were studied. The significant improvement in the HIBP beam control system and the acquisition electronics leads us to increase the possibilities of the diagnostic. The most crucial one is the extension of the signal dynamic range, which allows us to have the reliable profiles from the plasma center to the plasma edge both in the high and low field side regions. Low density ECRH (n = 0.5-1.1.10 13 cm -3 ) plasmas in TJ-2 are characterised by core positive plasma potential of order of 500 - 1000 V and positive electric fields up to 50 V/cm. Edge radial electric fields remain positive at low densities and became negative at the threshold density that depends of plasma configuration. NBI plasmas are characterized by negative electric potential in the full plasma column and negative radial electric fields (in the range of 10 - 40 V/cm). The density rise during the NBI phase is accompanied by the decay of core plasma potential. When density is getting the level of n ∼ 2.0.10 13 cm -3 , the potential stops its evolution and remains constant. The evolution of plasma potential near density limit is under investigation. These observations, reported in different magnetic configurations, show the clear link between plasma potential and plasma density. (author)

Experiments and simulations for the dynamics of cesium in negative hydrogen ion sources for ITER N-NBI

Energy Technology Data Exchange (ETDEWEB)

Gutser, Raphael

2010-07-21

The injection of fast neutral particles (NBI) into a fusion plasma is an important method for plasma heating and current drive. A source for negative deuterium ions delivering an 1 MeV beam that is accelerated to a specific energy and neutralized by a gas target is required for the ITER-NBI. Cesium seeding is required to extract high negative ion current densities from these sources. The optimization of the cesium homogeneity and control are major objectives to achieve the source requirements imposed by ITER. Within the scope of this thesis, the Monte Carlo based numerical transport simulation CsFlow3D was developed, which is the first computer model that is capable of simulating the flux and the accumulation of cesium on the surfaces of negative-ion sources. Basic studies that support the code development were performed at a dedicated experiment at the University of Augsburg. Input parameters of the ad- and desorption of cesium at ion source relevant conditions were taken from systematic measurements with a quartz micro balance, while the injection rate of the cesium oven at the ion source was determined by surface ionization detection. This experimental setup was used for further investigations of the work function of cesium-coated samples during plasma exposure. (orig.)

Experiments and simulations for the dynamics of cesium in negative hydrogen ion sources for ITER N-NBI

International Nuclear Information System (INIS)

Gutser, Raphael

2010-01-01

The injection of fast neutral particles (NBI) into a fusion plasma is an important method for plasma heating and current drive. A source for negative deuterium ions delivering an 1 MeV beam that is accelerated to a specific energy and neutralized by a gas target is required for the ITER-NBI. Cesium seeding is required to extract high negative ion current densities from these sources. The optimization of the cesium homogeneity and control are major objectives to achieve the source requirements imposed by ITER. Within the scope of this thesis, the Monte Carlo based numerical transport simulation CsFlow3D was developed, which is the first computer model that is capable of simulating the flux and the accumulation of cesium on the surfaces of negative-ion sources. Basic studies that support the code development were performed at a dedicated experiment at the University of Augsburg. Input parameters of the ad- and desorption of cesium at ion source relevant conditions were taken from systematic measurements with a quartz micro balance, while the injection rate of the cesium oven at the ion source was determined by surface ionization detection. This experimental setup was used for further investigations of the work function of cesium-coated samples during plasma exposure. (orig.)

Exit points, on plasma, of lost fast ions during NBI in TJ-II

International Nuclear Information System (INIS)

Guasp, J.

1995-01-01

The distribution of the exit points, on plasma border, for the lost fast ions during tangential balanced NBI in TJ-II helical axis Stellarator is theoretically analysed, as well for direct as for delayed losses. The link between, the position of those exit points and the corresponding at birth, orbits and drifts is analysed also. It is shown that such relation is rather independent of beam energy and plasma density and is mainly related to the magnetic configuration characteristics. This study is a needed intermediate step to the analysis of impacts of those ions on the vacuum vessel of TJ-II. (Author) 2 refs

Fundamental ion cyclotron resonance heating of JET deuterium plasmas

International Nuclear Information System (INIS)

Krasilnikov, A V; Amosov, V N; Kaschuck, Yu A; Van Eester, D; Lerche, E; Ongena, J; Bonheure, G; Biewer, T; Crombe, K; Ericsson, G; Giacomelli, L; Hellesen, C; Hjalmarsson, A; Esposito, B; Marocco, D; Jachmich, S; Kiptily, V; Leggate, H; Mailloux, J; Kallne, J

2009-01-01

Radio frequency heating of majority ions is of prime importance for understanding the basic role of auxiliary heating in the activated D-T phase of ITER. Majority deuterium ion cyclotron resonance heating (ICRH) experiments at the fundamental cyclotron frequency were performed in JET. In spite of the poor antenna coupling at 25 MHz, this heating scheme proved promising when adopted in combination with D neutral beam injection (NBI). The effect of fundamental ICRH of a D population was clearly demonstrated in these experiments: by adding ∼25% of heating power the fusion power was increased up to 30-50%, depending on the type of NBI adopted. At this power level, the ion and electron temperatures increased from T i ∼ 4.0 keV and T e ∼ 4.5 keV (NBI-only phase) to T i ∼ 5.5 keV and T e ∼ 5.2 keV (ICRH + NBI phase), respectively. The increase in the neutron yield was stronger when 80 keV rather than 130 keV deuterons were injected in the plasma. It is shown that the neutron rate, the diamagnetic energy and the electron as well as the ion temperature scale roughly linearly with the applied RF power. A synergistic effect of the combined use of ICRF and NBI heating was observed: (i) the number of neutron counts measured by the neutron camera during the combined ICRF + NBI phases of the discharges exceeded the sum of the individual counts of the NBI-only and ICRF-only phases; (ii) a substantial increase in the number of slowing-down beam ions was detected by the time of flight neutron spectrometer when ICRF power was switched on; (iii) a small D subpopulation with energies slightly above the NBI launch energy was detected by the neutral particle analyzer and γ-ray spectroscopy.

INTERACTION OF NEUTRAL BEAM INJECTED FAST IONS WITH ION CYCLOTRON RESONANCE FREQUENCY WAVES

International Nuclear Information System (INIS)

CHOI, M.; CHAN, V.S.; CHIU, S.C.; OMELCHENKO, Y.A.; SENTOKU, Y.; STJOH, H.E.

2003-01-01

OAK B202 INTERACTION OF NEUTRAL BEAM INJECTED FAST IONS WITH CYCLOTRON RESONANCE FREQUENCY WAVES. Existing tokamaks such as DIII-D and future experiments like ITER employ both NB injection (NBI) and ion-cyclotron resonance heating (ICRH) for auxiliary heating and current drive. The presence of energetic particles produced by NBI can result in absorption of the Ion cyclotron radio frequency (ICRF) power. ICRF can also interact with the energetic beam ions to alter the characteristics of NBI momentum deposition and resultant impact on current drive and plasma rotation. To study the synergism between NBI and ICRF, a simple physical model for the slowing-down of NB injected fast ions is implemented in a Monte-Carlo rf orbit code. This paper presents the first results. The velocity space distributions of energetic ions generated by ICRF and NBI are calculated and compared. The change in mechanical momentum of the beam and an estimate of its impact on the NB-driven current are presented and compared with ONETWO simulation results

High fusion performance at high T i/T e in JET-ILW baseline plasmas with high NBI heating power and low gas puffing

Science.gov (United States)

Kim, Hyun-Tae; Sips, A. C. C.; Romanelli, M.; Challis, C. D.; Rimini, F.; Garzotti, L.; Lerche, E.; Buchanan, J.; Yuan, X.; Kaye, S.; contributors, JET

2018-03-01

This paper presents the transport analysis of high density baseline discharges in the 2016 experimental campaign of the Joint European Torus with the ITER-Like Wall (JET-ILW), where a significant increase in the deuterium-deuterium (D-D) fusion neutron rate (~2.8  ×  1016 s-1) was achieved with stable high neutral beam injection (NBI) powers of up to 28 MW and low gas puffing. Increase in T i exceeding T e were produced for the first time in baseline discharges despite the high electron density; this enabled a significant increase in the thermal fusion reaction rate. As a result, the new achieved record in fusion performance was much higher than the previous record in the same heating power baseline discharges, where T i  =  T e. In addition to the decreases in collisionality and the increases in ion heating fraction in the discharges with high NBI power, T i  >  T e can also be attributed to positive feedback between the high T i/T e ratio and stabilisation of the turbulent heat flux resulting from the ion temperature gradient driven mode. The high T i/T e ratio was correlated with high rotation frequency. Among the discharges with identical beam heating power, higher rotation frequencies were observed when particle fuelling was provided by low gas puffing and pellet injection. This reveals that particle fuelling played a key role for achieving high T i/T e, and the improved fusion performance.

Progress of the ITER NBI acceleration grid power supply reference design

International Nuclear Information System (INIS)

Toigo, Vanni; Zanotto, Loris; Bigi, Marco; Decamps, Hans; Ferro, Alberto; Gaio, Elena; Gutiérrez, Daniel; Tsuchida, Kazuki; Watanabe, Kazuhiro

2013-01-01

Highlights: ► This paper reports the progress in the reference design of the Acceleration Grid Power Supply (AGPS) of the ITER Neutral Beam Injector (NBI) ► A critical revision of the main design choices is presented in light of the definition of some key interface parameters between the two AGPS subsystems. ► The verification of the fulfillment of the requirements in any operational conditions is reported and discussed. -- Abstract: This paper reports the progress in the reference design of the Acceleration Grid Power Supply (AGPS) of the ITER Neutral Beam Injector (NBI). The design of the AGPS is very challenging, as it shall be rated to provide about 55 MW at 1 MV dc in quasi steady-state conditions; moreover, the procurement of the system is shared between the European Domestic Agency (F4E) and the Japanese Domestic Agency (JADA), resulting in additional design complication due to the need of a common definition of the interface parameters. A critical revision of the main design choices is presented also in light of the definition of some key interface parameters between the two AGPS subsystems. Moreover, the verification of the fulfillment of the requirements in any operational conditions taking into account the tolerance of the different parameters is also reported and discussed

On the NBI system for substantial current drive in a fusion power plant: Status and R and D needs for ion source and laser neutralizer

International Nuclear Information System (INIS)

Franzen, P.; Fantz, U.

2014-01-01

Highlights: • NBI is a candidate for a cw tokamak DEMO due to its high current drive efficiency. • The plug-in efficiency must be improved from the present 20–30% to more than 50%. • A suitable candidate is a photo neutralizer with almost 100% neutralization efficiency; basic feasibility studies are underway. • Cw operation with a large availability puts rather high demands on source operation with some safety margins, especially for the components with high power density loads (source back plate and extraction system). • Alternatives to the present use of cesium are under exploitations. - Abstract: The requirements for the heating and current drive systems of a fusion power plant will strongly depend on the DEMO scenario. The paper discusses the R and D needs for a neutral beam injection system — being a candidate due to the highest current drive efficiency — for the most demanding scenario, a steady state tokamak DEMO. Most important issues are the improvement of the wall-plug efficiency from the present ∼25% to the required 50–60% by improving the neutralization efficiency with a laser neutralizer system and the improvement of the reliability of the ion source operation. The demands on and the potential of decreasing the ion source operation pressure, as well as decreasing the amount of co-extracted electrons and backstreaming ions are discussed using the ITER requirements and solutions as basis. A further concern is the necessity of cesium for which either the cesium management must be improved or alternatives to cesium for the production of negative ions have to be identified

Design issues of the High Voltage platform and feedthrough for the ITER NBI Ion Source

International Nuclear Information System (INIS)

Boldrin, M.; Palma, M. Dalla; Milani, F.

2009-01-01

In the ITER heating Neutral Beam Injector (NBI), a High Voltage air-insulated platform (named High Voltage Deck, HVD) will be installed to host the Ion Source and Extractor Power supply system and associated diagnostics referred to -1 MV DC potential. All power and control cables are routed from the HVD via a feedthrough (HV bushing) to the gas insulated transmission line which feeds the Injector. The paper focuses on insulation and mechanical issues for both HVD and HV bushing which are very special components, far from the present industrial standards as far as voltage (-1 MV DC) and dimensions are concerned. For this purpose, a preliminary design of the HVD has been carried out as concerns the mechanical structure and external shield. Then, the structure has been verified with a seismic analysis applying the seismic load excitation specified for the ITER construction site (Cadarache) and carrying out verifications according to relevant international standards. As regards the HV bushing design, proposals for the complex inner conductor structure and for interfaces to the HVD and transmission line are outlined; alternative installation layouts (aside or underneath the HVD) are compared from both mechanical and electrical points of view.

Physical performance analysis and progress of the development of the negative ion RF source for the ITER NBI system

International Nuclear Information System (INIS)

Fantz, U.; Franzen, P.; Kraus, W.; Berger, M.; Christ-Koch, S.; Falter, H.; Froeschle, M.; Gutser, R.; Heinemann, B.; Martens, C.; McNeely, P.; Riedl, R.; Speth, E.; Staebler, A.; Wuenderlich, D.

2009-01-01

For heating and current drive the neutral beam injection (NBI) system for ITER requires a 1 MeV deuterium beam for up to 1 h pulse length. In order to inject the required 17 MW the large area source (1.9 m x 0.9 m) has to deliver 40 A of negative ion current at the specified source pressure of 0.3 Pa. In 2007, the IPP RF driven negative hydrogen ion source was chosen by the ITER board as the new reference source for the ITER NBI system due to, in principle, its maintenance free operation and the progress in the RF source development. The performance analysis of the IPP RF sources is strongly supported by an extensive diagnostic program and modelling of the source and beam extraction. The control of the plasma chemistry and the processes in the plasma region near the extraction system are the most critical topics for source optimization both for long pulse operation as well as for the source homogeneity. The long pulse stability has been demonstrated at the test facility MANITU which is now operating routinely at stable pulses of up to 10 min with parameters near the ITER requirements. A quite uniform plasma illumination of a large area source (0.8 m x 0.8 m) has been demonstrated at the ion source test facility RADI. The new test facility ELISE presently planned at IPP is being designed for long pulse plasma operation and short pulse, but large-scale extraction from a half-size ITER source which is an important intermediate step towards ITER NBI.

Effect of plasma rotation on sawtooth stabilization by beam ion

International Nuclear Information System (INIS)

Gorelenkov, N. N.; Nave, M. F. F.; Budny, R.; Cheng, C. Z.; Fu, G. Y.; Hastie, J.; Manickam, J.; Park, W.

2000-01-01

The sawtooth period in JET ELM-free H-Mode plasmas is increasing with Neutral Beam Injection (NBI) power. For injected power PNBI 12MW no large sawtooth crash is observed during the ELM-free period. However, as the edge stability is improved and external kink modes and ELMs are delayed, a possible sawtooth crash at a high plasma beta becomes a concern. In JET DT experiments, delaying sawteeth was found to be crucial in the quest for high fusion power. Fast particles are known to provide stabilizing effect on sawteeth, however, sawtooth stabilization by NBI ions is not clearly understood, since NBI ions are usually not ''fast'' enough to stabilize the m/n = 1/1 internal kink mode which is believed to cause the crash. In order to understand the observed sawteeth stabilization in tokamak experiments with NBI heating, the internal kink m/n = 1/1 mode stability of JET plasmas was modeled using the NOVA-K code, which is also benchmarked with the nonperturbative version of NOVA and the M3D code. Comparison of m/n = 1/1 mode stabilization by NBI ions in JET and TFTR and application of the nonlinear stabilization criteria is given

Power supply for plasma generator of HL-1M neutral beam injector

International Nuclear Information System (INIS)

Wang Detai; Qian Jiamei; Lei Guangjiu; Shun Mengda; Jiang Shaofeng; Wang Enyao; Lu Xuejun; Yang Tiehai; Wang Xuehua; Zhao Zhimin; Hao Ming; Huang Jianrong; Yu Yanqiu; Cheng Baoqiang; Wu Zhige; Sheng Ning; Hu Qingtao

1999-01-01

The diagram of the HL-1M Neutral Beam Injector (NBI) and the power supply (PS) system is shown. The NBI consists of ion source, beam line and power supply system etc. The ion source includes plasma generator and three-electrode extraction system. The power supply for plasma generator consists of a filament PS, an arc PS and gas valve PS. Testing has shown that the PS for plasma generator of the HL-1M NBI has excellent stability and obtain good plasma heating effect

Design of a new P-NBI control system for 100-s injection in JT-60SA

International Nuclear Information System (INIS)

Okano, F.; Shinozaki, S.; Honda, A.; Ooshima, K.; Numazawa, S.; Ikeda, Y.

2008-01-01

Modification of JT-60U to a superconducting device (so-called JT-60SA) has been planned to contribute to ITER and DEMO. The positive-ion-based NBI system (P-NBI) is required to inject 24 MW for 100 s with 12 units. The P-NBI control system is to be fully remodeled with PLC (Programmable Logic Controller), which is featured by high market availability, system extensibility, cost-effectiveness, and independent development in programming. One of the critical issues to apply the PLC to the P-NBI control system is to control quickly the high voltage power supplies within 200 μs. For this purpose, the fastest PLC dealing with 4 refresh words at the processing time of 200 μs is to be employed. The second issue is to construct a data acquisition system for such a large number of data channels (∼2300 digital and ∼1300 analog data channels). The use of PLC linked with PC-based data measurement devices via Ethernet allows processing the large number of channels. The third issue is to make the man-machine interface simple. The marketed software giving an easy product of graphic menus is available for PLC programming. From these results, it is expected that commercial PLC could be applied to the large-scale control system of the P-NBI system for 100 s operations

Analysis of resonant fast ion distributions during combined ICRF and NBI heating with transients using neutron emission spectroscopy

Science.gov (United States)

Hellesen, C.; Mantsinen, M.; Conroy, S.; Ericsson, G.; Eriksson, J.; Kiptily, V. G.; Nabais, F.; Contributors, JET

2018-05-01

ICRF heating at the fundamental cyclotron frequency of a hydrogen minority ion species also gives rise to a partial power absorption by deuterium ions at their second harmonic resonance. This paper studies the deuterium distributions resulting from such 2nd harmonic heating at JET using neutron emission spectroscopy data from the time of flight spectrometer TOFOR. The fast deuterium distributions are obtained over the energy range 100 keV to 2 MeV. Specifically, we study how the fast deuterium distributions vary as ICRF heating is used alone as well as in combination with NBI heating. When comparing the different heating scenarios, we observed both a difference in the shapes of the distributions as well as in their absolute level. The differences are most pronounced below 0.5 MeV. Comparisons are made with corresponding distributions calculated with the code PION. We find a good agreement between the measured distributions and those calculated with PION, both in terms of their shapes as well as their amplitudes. However, we also identified a period with signs of an inverted fast ion distribution, which showed large disagreements between the modeled and measured results. Resonant interactions with tornado modes, i.e. core localized toroidal alfven eigenmodes (TAEs), are put forward as a possible explanation for the inverted distribution.

Impacts of lost fast ions on the TJ-II Vacuum Vessel during NBI; Impactos de los iones rapidos en la Camara de Vacio del TJ-II durante NBI

Energy Technology Data Exchange (ETDEWEB)

Guasp, J

1995-07-01

The possible deposition patterns, on the Vacuum Vessel, of lost fast ions during the balanced tangential NBI in TJ-II helical axis Stellarator are analysed theoretically, establishing the relation between those impact points, the plasma exit and birth positions and the magnetic configuration characteristics. It is shown that direct losses are the most important, mainly those produced by the beam injected with the same direction that the magnetic field, increasing with beam energy and plasma density but with impacts remaining fixed on well defined zones, a periodically distributed along the Hard Core cover plates, producing high loads at high densities. The remaining losses, except for the shine through ones that predominate at low density, are periodically distributed, with smooth maxima and produce very low loads. No overlapping between the different kind of losses or beams is observed. (Author) 6 refs.

Modelling of combined ICRF and NBI heating in JET hybrid plasmas

Directory of Open Access Journals (Sweden)

Gallart Dani

2017-01-01

Full Text Available During the 2015-2016 JET campaigns many efforts have been devoted to the exploration of high performance plasma scenarios envisaged for ITER operation. In this paper we model the combined ICRF+NBI heating in selected key hybrid discharges using PION. The antenna frequency was tuned to match the cyclotron frequency of minority hydrogen (H at the center of the tokamak coinciding with the second harmonic cyclotron resonance of deuterium. The modelling takes into account the synergy between ICRF and NBI heating through the second harmonic cyclotron resonance of deuterium beam ions which allows us to assess its impact on the neutron rate RNT. We evaluate the influence of H concentration which was varied in different discharges in order to test their role in the heating performance. According to our modelling, the ICRF enhancement of RNT increases by decreasing the H concentration which increases the ICRF power absorbed by deuterons. We find that in the recent hybrid discharges this ICRF enhancement was in the range of 10-25%. Finally, we extrapolate the results to D-T and find that the best performing hybrid discharges correspond to an equivalent fusion power of ∼7.0 MW in D-T.

Homodyne reflectometer for NBI interlock on Large Helical Device

International Nuclear Information System (INIS)

Tanaka, Kenji; Ito, Yasuhiko; Kawahata, Kazuo; Tokuzawa, Tokihiko; Osakabe, Masaki; Takeiri, Yasuhiko; Ejiri, Akira

2001-01-01

Neutral Beam Injection (NBI) under low density causes serious damage on vacuum vessel wall. It is necessary to stop NBI when electron density becomes lower than 1x10 19 m -3 . This needs reliable density monitor for NBI interlock. A three-channel homodyne reflectometer was installed on Large Helical Device (LHD) and was used for NBI interlock. 28.5, 34.9 and 40.2 GHz Gunn oscillators were used with O mode injection. Their O mode cut off density correspond to 1x10 19 , 1.5x10 19 and 2x10 19 m -3 respectively. The simple homodyne detection is presently used. When the density reaches to the cutoff density, the reflected signals are detected. The reflected signal consists of DC signal due to local and reflected power, and AC signal due to position of cut off layer and density fluctuation. Since the change of DC signal at lower and higher than cut off density was very small, root mean square (RMS) value of AC signal were used for interlock signal. This interlock system is successfully working from the beginning of the NBI experiments campaign on LHD. (author)

On the electron extraction in a large RF-driven negative hydrogen ion source for the ITER NBI system

International Nuclear Information System (INIS)

Franzen, P; Wünderlich, D; Fantz, U

2014-01-01

The test facility ELISE, equipped with a large RF-driven ion source (1 × 0.9 m 2 ) of half the size of the ion source for the ITER neutral beam injection (NBI) system, has been constructed over the last three years at the Max-Planck-Institut für Plasmaphysik (IPP), Garching, and is now operational. The first measurements of the dependence of the co-extracted electron currents on various operational parameters have been performed. ELISE has the unique feature that the electron currents can be measured individually on both extraction grid segments, leading to vertical spatial resolution. Although performed in volume operation, where the negative hydrogen ions are created in the plasma volume solely, the results are very encouraging for operation with caesium, this being necessary in order to achieve the relevant negative ion currents for the ITER NBI injectors. The amount of co-extracted electrons could be suppressed sufficiently with moderate magnetic filter fields and by plasma grid bias. Furthermore, the electron extraction is more or less decoupled from the main plasma, as the observed vertical asymmetry of electron extraction is not correlated at all with the plasma asymmetry, which is anyway rather small. Both effects are superior to the experience from the small IPP prototype source; the reason for these encouraging results is most probably the larger size of the source as well as the new geometry of the source having unbiased areas in its centre. The reasons, however, for the observed asymmetry of the extracted electron currents and their dependencies on various operational parameters are not well understood. (paper)

NBI Calculations for the TJ-II Experimental Discharges

International Nuclear Information System (INIS)

Guasp, J.; Fuentes, C.; Liniers, M.

2005-01-01

The density and electron temperature radial profiles, corresponding to the experimental TJ-II campaigns 2003-2004, with NBI, have been fitted to simple functionals in order to allow a fast approximative evaluation for any given density and injected power... The fits have been calculated, separately, for the four possibilities: ECRH and NBI Phases as well as On and Off Axis ECRH injection. The average difference between the experimental profiles for the individual discharges and the fit predictions are around 8% for the density and 10% for the temperature. The behaviour of the predicted profiles with average line density and injected power has been analysed. The central electron temperature decreases monotonically with increasing density and the ECRH phase On Axis central value is clearly higher than the Off axis one. The radial density profiles narrow with increasing density and the NBI On axis case is clearly wider than de Off one. The electron temperature profile widens slightly with increasing density and the width of the On Axix case is lesser than for the Off case in all phases. There exist Fortran subroutines, available at the three CIEMAT computers, allowing the fast approximative evaluation of all these profiles. (Author) 8 refs

The Implementation of Computer Data Processing Software for EAST NBI

International Nuclear Information System (INIS)

Zhang Xiaodan; Hu Chundong; Sheng Peng; Zhao Yuanzhe; Wu Deyun; Cui Qinglong

2014-01-01

One of the most important project missions of neutral beam injectors is the implementation of 100 s neutral beam injection (NBI) with high power energy to the plasma of the EAST superconducting tokamak. Correspondingly, it's necessary to construct a high-speed and reliable computer data processing system for processing experimental data, such as data acquisition, data compression and storage, data decompression and query, as well as data analysis. The implementation of computer data processing application software (CDPS) for EAST NBI is presented in this paper in terms of its functional structure and system realization. The set of software is programmed in C language and runs on Linux operating system based on TCP network protocol and multi-threading technology. The hardware mainly includes industrial control computer (IPC), data server, PXI DAQ cards and so on. Now this software has been applied to EAST NBI system, and experimental results show that the CDPS can serve EAST NBI very well. (fusion engineering)

Impacts of lost fast ions on the TJ-II Vacuum Vessel during NBI

International Nuclear Information System (INIS)

Guasp, J.

1995-01-01

The possible deposition patterns, on the Vacuum Vessel, of lost fast ions during the balanced tangential NBI in TJ-II helical axis Stellarator are analysed theoretically, establishing the relation between those impact points, the plasma exit and birth positions and the magnetic configuration characteristics. It is shown that direct losses are the most important, mainly those produced by the beam injected with the same direction that the magnetic field, increasing with beam energy and plasma density but with impacts remaining fixed on well defined zones, a periodically distributed along the Hard Core cover plates, producing high loads at high densities. The remaining losses, except for the shine through ones that predominate at low density, are periodically distributed, with smooth maxima and produce very low loads. No overlapping between the different kind of losses or beams is observed. (Author) 6 refs

Impacts of lost fast ions on the TJ-II Vacuum vessel during NBI

International Nuclear Information System (INIS)

Guasp, J.

1995-09-01

The possible deposition patterns, on the Vacuum Vessel, of lost fast ions during the balanced tangential NBI in TJ-II helical axis Stellarator are analysed theoretically, establishing the relation between those impact points, the plasma exit and birth positions and positions and the magnetic configuration characteristics. It is shown that direct losses are the most important, mainly those produced by the beam injected with the same direction that the magnetic field, increasing with beam energy and plasma density but with impacts remaining fixed on well defined zones, a periodically distributed along the Hard Core cover plates, producing high loads at high densities. The remaining losses, except for the shine through ones that predominate at low density, are periodically distributed, with smooth maxima and produce very low loads. No overlapping between the different kind of losses or beams is observed

Integration of cryopump instrumentation for SST-1 NBI

International Nuclear Information System (INIS)

Bansal, Laxmi Kant; Patel, Paresh J.; Prahlad, V.

2015-01-01

A positive ion neutral injector (PINI) capable in delivering 5MW (55kV, 90A) ion beam power is being operated for SST-1 neutral beam injection (NBI). The production and neutralization of the ion beams in the injector requires a gas throughput of 20 torr I/s in the plasma box and 50-100 torr I/s in the neutralizer section. It is necessary to maintain operating pressure of vessel at 10 -5 torr to reduce the re-ionization loss of beam within tolerable limits. Conventional Turbo molecular pumps cannot maintain this vacuum level at required gas feed rate so two cryo condensation pumps are being operated to achieve require vacuum in vessel. In order to monitor and optimize the performance of cryopumps, it is necessary to measure the temperature at various locations in LN 2 and LHe path. It is also required to monitor the level of LHe and LN 2 in cryopumps. Several temperature and level sensors are mounted at various places in cryopumps and integrated with PLC and SCADA based control system. This paper presents the details of sensor mounting, signals conditioning, scheme of their integration with PLC and SCADA and results in detail. (author)

NBI Calculations for the TJ-II Experimental discharges

International Nuclear Information System (INIS)

Guasp, J.; Fuentes, C.; Liniers, M.

2004-01-01

Calculations for NBI losses, absorption and power deposition radial profiles, corresponding to the experimental TJ-II campaigns 2003-2004, have been fitted to simple functionals in order to allow a fast approximative evaluation for any given density. The average difference between the calculations for the individual discharges using the experimental density and temperature radial profiles and the fit predictions are between 10 and 15% and the behaviour with density is the expected one: nonotonic decrease of shine through losses and increase of absorption with incipient saturation for high densities. The fast ion birth radial profile narrows initially at low densities but later starts to widen, although, for the average line density range analysed (0.51 a 4.1x10''13 cm''-3), never are wide enough to induce an increase of direct orbit losses neither to produce hollow radial profiles. The power absorption radial profile widens nonotonically. There exist Fortran subroutines, available at the three CIEMAT computers, allowing the fast approximative evaluation of all these values. (Author) 8 refs

A review of JAERI R and D activities on the negative-ion-based neutral beam injection system

International Nuclear Information System (INIS)

Ohara, Yoshihiro; Akiba, Masato; Araki, Masanori

1990-08-01

R and D efforts to realize a negative-ion-based neutral beam injection system have been made intensively at JAERI for the past several years. Concerning a high current negative ion source which is one of the most important R and D items, a 10 A, 50 keV negative hydrogen ion beam has been produced successfully. The negative ion beam current and the current density correspond already to the value required for the negative-ion-based NBI system. In order to increase the beam energy further, a 350 keV, 0.1 A test stand has been constructed, and the test of a high energy negative ion accelerator has started. Concerning a high energy acceleration power supply, an inverter type power supply which has a high speed AC switch was proposed and applied to the 100 kV, 5 A power supply for JAERI Electron Beam Irradiation Stand. The reliable operation indicates that the concept of this system can be applied for a MV class acceleration power supply. As one of the promising candidates for a beam dump cooling element, an externally-finned swirl tube was proposed and tested to have a high burnout heat flux of 4.1 kW/cm 2 , which is high enough for the next NBI system. The R and Ds on the negative-ion-based NBI system have made great progress at JAERI in recent years. The construction of a 500 keV class NBI system has become realistic from the engineering point of view. (author)

Ion cyclotron heating of JET D-D and D-T optimised shear plasmas

International Nuclear Information System (INIS)

Cottrell, G.; Baranov, Y.; Bartlett, D.

1998-12-01

This paper discusses the unique roles played by Ion Cyclotron Resonance Heating (ICRH) in the preparation, formation and sustainment of internal transport barriers (ITBs) in high fusion performance JET optimised shear experiments using the Mk. H poloidal divertor. Together with Lower Hybrid Current Drive (LHCD), low power ICRH is applied during the early ramp-up phase of the plasma current, 'freezing in' a hollow or flat current density profile with q(0)>1. In combination with up to ∼ 20 MW of Neutral Beam Injection (NBI), the ICRH power is stepped up to ∼ 6 MW during the main low confinement (L-mode) heating phase. An ITB forms promptly after the power step, revealed by a region of reduced central energy transport and peaked profiles, with the ion thermal diffusivity falling to values close to the standard neo-classical level near the centre of both D-D and D-T plasmas. At the critical time of ITB formation, the plasma contains an energetic ICRF hydrogen minority ion population, contributing ∼ 50% to the total plasma pressure and heating mainly electrons. As both the NBI population and the thermal ion pressure develop, a substantial part of the ICRF power is damped resonantly on core ions (ω = 2 ω cD = 3 ω cT ) contributing to the ion heating. In NBI step-down experiments, high performance has been sustained by maintaining central ICRH heating; analysis shows the efficiency of central ICRH ion heating to be comparable with that of NBI. The highest D-D fusion neutron rates (R NT = 5.6 x 10 16 s -1 ) yet achieved in JET plasmas have been produced by combining a low magnetic shear core with a high confinement (H-mode) edge. In D-T, a fusion triple product n i T i τ E = (1.2 ± 0.2) x 10 21 m -3 keVs was achieved with 7.2 MW of fusion power obtained in the L-mode and up to 8.2 MW of fusion power in the H-mode phase. (author)

NBI Calculations for the TJ-II Experimental Discharges; Ajustes de los Perfiles Radiales de Densidad y Temperatura para las Descargas con NBI del TJ-II

Energy Technology Data Exchange (ETDEWEB)

Guasp, J.; Fuentes, C.; Liniers, M.

2005-07-01

The density and electron temperature radial profiles, corresponding to the experimental TJ-II campaigns 2003-2004, with NBI, have been fitted to simple functionals in order to allow a fast approximative evaluation for any given density and injected power... The fits have been calculated, separately, for the four possibilities: ECRH and NBI Phases as well as On and Off Axis ECRH injection. The average difference between the experimental profiles for the individual discharges and the fit predictions are around 8% for the density and 10% for the temperature. The behaviour of the predicted profiles with average line density and injected power has been analysed. The central electron temperature decreases monotonically with increasing density and the ECRH phase On Axis central value is clearly higher than the Off axis one. The radial density profiles narrow with increasing density and the NBI On axis case is clearly wider than de Off one. The electron temperature profile widens slightly with increasing density and the width of the On Axix case is lesser than for the Off case in all phases. There exist Fortran subroutines, available at the three CIEMAT computers, allowing the fast approximative evaluation of all these profiles. (Author) 8 refs.

Behaviour of direct and delayed fast ion losses during NBI on TJ-II

International Nuclear Information System (INIS)

Guasp, J.; Liniers; M.

1995-09-01

The dependence with density and beam energy of the different kind of fast ion losses, direct and delayed, during tangential balanced NBI injection in TJ-II helical axis stellerator has been analysed. Direct losses increase with energy and a strong difference between the two injection directions appears, are produced by passing particles that loss confinement in a dew mu,sec and the influence of birth profiles produces an increase with density. Delayed losses are very well separated in time from direct ones, are produced by particles experimenting pitch angle scattering an,d, most o them, correspond to trapped particles. Are much less important than the direct ones (about 1/3), decrease slowly with energy and, with CX, increase with density (an effect of initial profile). The absorption is rather independent of energy with low values at low density in reason of high shine trough and CX losses, but reovers quickly with the density increase

Behaviour of direct and delayed fast ion losses during NBI on TJ-II

International Nuclear Information System (INIS)

Guasp, J.; Liniers, M.

1995-01-01

The dependence with density and beam energy of the different kind of fast ion losses, direct and delayed, during tangential balanced NBI injection in TJ-II helical axis stellarator has been analysed. Direct losses increase with energy and a strong difference between the two injection directions appears, are produced by passing particles that loss confinement in a few μsec and the influence of birth profiles produces an increase with density. Delayed losses are very well separated in time from direct ones, are produced by particles experimenting pitch angle scattering and, most o them, correspond to trapped particles. Are much less important than the direct ones (about 1/3), decrease slowly with energy and, with C X, increase with density (an effect of initial profile). The absorption is rather independent of energy with low values at low density in reason of high shine through and C X losses, but recovers quickly with the density increase. (Author) 4 refs

Edge localized modes and edge pedestal in NBI and ICRF heated H, D and T-plasmas in JET

International Nuclear Information System (INIS)

Bhatnagar, V.; Lingertat, J.; Barnsley, R.

1998-12-01

Based on experiments carried out in JET in D:T mixtures varying from 100:0 to 5:95 and those carried out in hydrogen plasmas, the isotopic mass dependence of ELM parameters and the edge pedestal pressure in neutral beam (NBI) and ion cyclotron resonance (ICRF) heated H-mode plasmas is presented. The ELM frequency is found to decrease with the atomic mass number both in ICRH and NBI discharges. However, the frequency in the case of ICRH is about 8 - 10 times higher than in the NBI case. Assuming that ELMs occur at a critical edge pressure gradient, limited by the ballooning instability, the scaling of the maximum edge pressure is most consistent with the assumption that the width of the transport barrier scales as the ion poloidal Larmor radius governed by the average energy of fast ions at the edge. The critical edge pressure in NBI heated discharges increases with the isotopic mass which. is consistent with the higher deduced width of the edge transport, barrier in tritium than in deuterium and hydrogen. The critical edge pressure in ICRH discharges is smaller, presumably, due to the smaller fast-ion contribution to the edge region. As a consequence of the edge pressure scaling with isotopic mass, the edge operational space in the n e - T e diagram increases with operation in tritium. If the evidence that the edge pedestal width is governed by the average energy of fast ions in the edge prevails, the pedestal in ITER would be controlled by the slowing down energy spectrum of α-particles in the edge. (author)

Design study of a new P-NBI control system for 100-s injection in JT-60SA

International Nuclear Information System (INIS)

Honda, Atsushi; Okano, Fuminori; Shinozaki, Shinichi; Ooshima, Katsumi; Ikeda, Yoshitaka; Numazawa, Susumu

2007-03-01

The modification of the JT-60U to a fully superconducting coil tokamak, JT-60SA (Super Advanced), has been programmed as the satellite devise for the ITER (International Thermonuclear Experimental Reactor) and as the national centralized tokamak. The present positive-ion-based NBI system (P-NBI), which has been operated for 20 years and will be the main heating system on JT-60SA, is required to manage the long pulse injection extended from 30 s to 100 s at the power of 24 MW with 12 units. To realize such a requirement, the original control system handling more than 4000 digital data is to be fully remodeled. Design study of the new control system has been conducted from viewpoint of market availability, system extensibility, cost-effectiveness and independent development in programming. It has been concluded that a distributed control system using PLC (Programmable Logic Controller) could be applied to the large-scale control system for 100-s operations with satisfaction of the evaluation viewpoints. (author)

Recent results with NBI plasmas in TJ-II stellarator

Energy Technology Data Exchange (ETDEWEB)

Liniers, M.; Ascasibar, E.; Estrada, T.; Tabares, F. L.; Acedo, M.; Alonso, J.; Balbin, R.; Blanco, B.; Branas, B.; Cappa, A.; Carrasco, R.; Castejon, F.; Fernandez, A.; Fontdecaba, J. M.; Fuentes, C.; Garcia, A.; Garcia-Cortes, I.; Guasp, J.; Hidalgo, A.; Hidalgo, C.; Jimenez, R.; Lopez-Bruna, D.; Lopez-Fraguas, A.; Marcon, G.; McCarthy, K. J.; Medina, F.; Medrano, M.; Ochando, M.; Pastor, I.; Pedrosa, M. A.; Rapisarda, D.; Sanchez, E.; Sanchez, M.; Sanchez, J.; Tafalla, D.; Wolfers, G.; Zurro, B.

2005-07-01

During the last experimental campaign Neutral Beam Injection into TJ-II plasmas has been available, with a single H0 beam aiming tangentially in the Co-direction. As the ion source conditioning was improved along the campaign, the injected power increased from 200 kW to 400 kW port-through, and the beam energy was raised from 26 kV to 30 kV [1]. Target plasmas are created by ECR heating, using two gyrotrons of 200 kW power, at the second harmonic frequency (53 GHz). The injection direction of the microwaves can be steered by means of movable mirrors placed inside the vacuum chamber, making it possible to vary the power deposition region from the plasma core (on-axis) to the outer regions near ?=0.5 (off-axis). The plasma temperature and density profiles obtained with on-axis or off axis ECRH are seen to differ widely, allowing us to study the neutral beam absorption in two qualitatively different plasma target scenarios. Other factors affecting the plasma profiles have also been investigated, such as the magnetic configuration or the OH-driven current. TJ-II has the capability of varying the magnetic configuration by changing the ratio of the current through the circular and helical conductors that form the Central Conductor. The iota values can be swept between 0.9 and 2.2 and the magnetic well between -1% and 6% giving rise to configurations with different confinement properties. A negative OH driven current has the effect of increasing the magnetic shear value, allowing low-order rationals in the central region which have been seen to modify density profiles in ECH plasmas. In most NBI discharges the central plasma density increases continuously from ECH typical values below 1.1 x 10 19 m-3 up to 6.5 x 10 19 m-3, as the beam is injected, until a thermal collapse that terminates the discharge is reached. So far, density control with NBI plasmas has not been achieved, although an improved behaviour is observed with wall cleaning. (Author)

Recent results with NBI plasmas in TJ-II stellarator

International Nuclear Information System (INIS)

Liniers, M.; Ascasibar, E.; Estrada, T.; Tabares, F. L.; Acedo, M.; Alonso, J.; Balbin, R.; Blanco, B.; Branas, B.; Cappa, A.; Carrasco, R.; Castejon, F.; Fernandez, A.; Fontdecaba, J. M.; Fuentes, C.; Garcia, A.; Garcia-Cortes, I.; Guasp, J.; Hidalgo, A.; Hidalgo, C.; Jimenez, R.; Lopez-Bruna, D.; Lopez-Fraguas, A.; Marcon, G.; McCarthy, K. J.; Medina, F.; Medrano, M.; Ochando, M.; Pastor, I.; Pedrosa, M. A.; Rapisarda, D.; Sanchez, E.; Sanchez, M.; Sanchez, J.; Tafalla, D.; Wolfers, G.; Zurro, B.

2005-01-01

During the last experimental campaign Neutral Beam Injection into TJ-II plasmas has been available, with a single H0 beam aiming tangentially in the Co-direction. As the ion source conditioning was improved along the campaign, the injected power increased from 200 kW to 400 kW port-through, and the beam energy was raised from 26 kV to 30 kV [1]. Target plasmas are created by ECR heating, using two gyrotrons of 200 kW power, at the second harmonic frequency (53 GHz). The injection direction of the microwaves can be steered by means of movable mirrors placed inside the vacuum chamber, making it possible to vary the power deposition region from the plasma core (on-axis) to the outer regions near ?=0.5 (off-axis). The plasma temperature and density profiles obtained with on-axis or off axis ECRH are seen to differ widely, allowing us to study the neutral beam absorption in two qualitatively different plasma target scenarios. Other factors affecting the plasma profiles have also been investigated, such as the magnetic configuration or the OH-driven current. TJ-II has the capability of varying the magnetic configuration by changing the ratio of the current through the circular and helical conductors that form the Central Conductor. The iota values can be swept between 0.9 and 2.2 and the magnetic well between -1% and 6% giving rise to configurations with different confinement properties. A negative OH driven current has the effect of increasing the magnetic shear value, allowing low-order rationals in the central region which have been seen to modify density profiles in ECH plasmas. In most NBI discharges the central plasma density increases continuously from ECH typical values below 1.1 x 10 19 m-3 up to 6.5 x 10 19 m-3, as the beam is injected, until a thermal collapse that terminates the discharge is reached. So far, density control with NBI plasmas has not been achieved, although an improved behaviour is observed with wall cleaning. (Author)

Active core profile and transport modification by application of Ion Bernstein Wave power in PBX-M

International Nuclear Information System (INIS)

LeBlanc, B.; Bell, R.

1995-01-01

Application of Ion Bernstein Wave Heating (IBWH) into the Princeton Beta Experiment-Modification (PBX-M) tokamak stabilizes sawtooth oscillations and generates peaked density profiles. A transport barrier, spatially correlated with the IBWH power deposition profile, is observed in the core of IBWH assisted neutral beam injection (NBI) discharges. A precursor to the fully developed barrier is seen in the soft x-ray data during edge localized mode (ELM) activity. Sustained IBWH operation is conducive to a regime where the barrier supports large triangledown n e , triangledown T e , triangledown v phi , and triangledown T i , delimiting the confinement zone. This regime is reminiscent of the H(high)-mode but with a confinement zone moved inwards. The core region has better than H-mode confinement while the peripheral region is L(low)-mode-like. The peaked profile enhanced NBI core deposition and increases nuclear reactivity. An increase in central T i results from χ i reduction (compared to H-mode) and better beam penetration. Bootstrap current fractions of up to 0.32--0.35 locally and 0.28 overall were obtained when an additional NBI burst is applied to this plasma

Characteristics of edge pedestals in LHW and NBI heated H-mode plasmas on EAST

Science.gov (United States)

Zang, Q.; Wang, T.; Liang, Y.; Sun, Y.; Chen, H.; Xiao, S.; Han, X.; Hu, A.; Hsieh, C.; Zhou, H.; Zhao, J.; Zhang, T.; Gong, X.; Hu, L.; Liu, F.; Hu, C.; Gao, X.; Wan, B.; the EAST Team

2016-10-01

By using the recently developed Thomson scattering diagnostic, the pedestal structure of the H-mode with neutral beam injection (NBI) or/and lower hybrid wave (LHW) heating on EAST (Experimental Advanced Superconducting Tokamak) is analyzed in detail. We find that a higher ratio of the power of the NBI to the total power of the NBI and the lower hybrid wave (LHW) will produce a large and regular different edge-localized mode (ELM), and a lower ratio will produce a small and irregular ELM. The experiments show that the mean pedestal width has good correlation with β \\text{p,\\text{ped}}0.5 , The pedestal width appears to be wider than that on other similar machines, which could be due to lithium coating. However, it is difficult to draw any conclusion of correlation between ρ * and the pedestal width for limited ρ * variation and scattered distribution. It is also found that T e/\

Power Law Distributions in the Experiment for Adjustment of the Ion Source of the NBI System

International Nuclear Information System (INIS)

Han Xiaopu; Hu Chundong

2005-01-01

The experiential adjustment process in an experiment on the ion source of the neutral beam injector system for the HT-7 Tokamak is reported in this paper. With regard to the data obtained in the same condition, in arranging the arc current intensities of every shot with a decay rank, the distributions of the arc current intensity correspond to the power laws, and the distribution obtained in the condition with the cryo-pump corresponds to the double Pareto distribution. Using the similar study method, the distributions of the arc duration are close to the power laws too. These power law distributions are formed rather naturally instead of being the results of purposeful seeking

Direct Measurement of Neutral/Ion Beam Power using Thermocouple Analysis

International Nuclear Information System (INIS)

Day, I.; Gee, S.

2006-01-01

Modern Neutral Beam Injection systems such as those used on JET and MAST routinely use thermocouples embedded close to the surface of beam stopping elements, such as calorimeters and ion dumps, coupled to high speed data acquisition systems to determine beam profile and position from temperature rise data. With the availability of low cost data acquisition and storage systems it is now possible to record data from all thermocouples in a fully instrumented calorimeter or ion dump on 20 ms timescales or better. This sample rate is sufficiently fast to enable the thermocouple data to be used to calculate the incident power density from 1d heat transfer theory. This power density data coupled with appropriate Gaussian fits enables the determination of the 2d beam profile and thus allows an instantaneous and direct measurement of beam power. The theory and methodology required to analyse the fast thermocouple data from the MAST calorimeter and residual ion dump thermocouples is presented and direct measurements of beam power density are demonstrated. The power of desktop computers allows such analysis to be carried out virtually instantaneously. The methods used to automate this analysis are discussed in detail. A code, utilising the theory and methodology, has been developed to allow immediate measurements of beam power on a pulse by pulse basis. The uncertainty in determining the beam power density is shown to be less than 10 %. This power density data is then fitted to a 2d Gaussian beam profile and integrated to establish the total beam power. Results of this automated analysis for the neutral beam and residual ion power of the MAST duopigatron and PINI NBI systems are presented. This technology could be applied to a beam power safety interlock system. The application to a beam shine through protection system for the inner wall of the JET Tokamak is discussed as an example. (author)

Scoping studies for NBI launch geometries on DEMO

Energy Technology Data Exchange (ETDEWEB)

Jenkins, I., E-mail: ian.jenkins@ukaea.uk; Challis, C.D.; Keeling, D.L.; Surrey, E.

2016-05-15

Highlights: • NBCD scans are done for beam energies of 1.5 MeV and 1.0 MeV in two DEMO scenarios. • NBCD scan profiles are fed into genetic algorithm to fit a target current profile. • The result gives location and power of sources to give best fit to target profile. • This method can help provide requirements for DEMO beamline geometry. - Abstract: Engineering and technical constraints on Neutral Beam Injection (NBI) in DEMO may determine the available beam energy and may also strongly impact the Neutral Beam Current Drive (NBCD) efficiency by restricting available beam tangential radii. These latter are determined by factors such as the inter-TF coil spacing, as well as the degree of required shielding. In order to illustrate how these factors may affect the contribution of NBCD on DEMO operating scenarios, scans of NBI tangency radii and elevation on two possible DEMO scenarios have been performed with two beam energies, 1.5 MeV and 1.0 MeV, in order to determine the most favourable options for NBCD efficiency. In addition, a method using a genetic algorithm has been used to seek optimised solutions of NBI source locations and powers to attempt to synthesize a target total plasma driven-current profile. It is found that certain beam trajectories may be proscribed by limitations on shinethrough onto the vessel wall. This may affect the ability of NBCD to extend the duration of a pulse in a scenario where it must complement the induced plasma current. Operating at the lower beam energy reduces the restrictions due to shinethrough and is attractive for technical reasons as it will required less development, but in the scenarios examined here this results in a spatial broadening of the NBCD profile, which may make it more challenging to achieve desired total driven-current profiles.

Active core profile and transport modification by application of ion Bernstein wave power in the Princeton Beta Experiment-Modification

Science.gov (United States)

LeBlanc, B.; Batha, S.; Bell, R.; Bernabei, S.; Blush, L.; de la Luna, E.; Doerner, R.; Dunlap, J.; England, A.; Garcia, I.; Ignat, D.; Isler, R.; Jones, S.; Kaita, R.; Kaye, S.; Kugel, H.; Levinton, F.; Luckhardt, S.; Mutoh, T.; Okabayashi, M.; Ono, M.; Paoletti, F.; Paul, S.; Petravich, G.; Post-Zwicker, A.; Sauthoff, N.; Schmitz, L.; Sesnic, S.; Takahashi, H.; Talvard, M.; Tighe, W.; Tynan, G.; von Goeler, S.; Woskov, P.; Zolfaghari, A.

1995-03-01

Application of Ion Bernstein Wave Heating (IBWH) into the Princeton Beta Experiment-Modification (PBX-M) [Phys. Fluids B 2, 1271 (1990)] tokamak stabilizes sawtooth oscillations and generates peaked density profiles. A transport barrier, spatially correlated with the IBWH power deposition profile, is observed in the core of IBWH-assisted neutral beam injection (NBI) discharges. A precursor to the fully developed barrier is seen in the soft x-ray data during edge localized mode (ELM) activity. Sustained IBWH operation is conducive to a regime where the barrier supports large ∇ne, ∇Te, ∇νφ, and ∇Ti, delimiting the confinement zone. This regime is reminiscent of the H(high) mode, but with a confinement zone moved inward. The core region has better than H-mode confinement while the peripheral region is L(low)-mode-like. The peaked profile enhances NBI core deposition and increases nuclear reactivity. An increase in central Ti results from χi reduction (compared to the H mode) and better beam penetration. Bootstrap current fractions of up to 0.32-0.35 locally and 0.28 overall were obtained when an additional NBI burst is applied to this plasma.

Active core profile and transport modification by application of ion Bernstein wave power in the Princeton Beta Experiment-Modification

International Nuclear Information System (INIS)

LeBlanc, B.; Batha, S.; Bell, R.; Bernabei, S.; Blush, L.; de la Luna, E.; Doerner, R.; Dunlap, J.; England, A.; Garcia, I.; Ignat, D.; Isler, R.; Jones, S.; Kaita, R.; Kaye, S.; Kugel, H.; Levinton, F.; Luckhardt, S.; Mutoh, T.; Okabayashi, M.; Ono, M.; Paoletti, F.; Paul, S.; Petravich, G.; Post-Zwicker, A.; Sauthoff, N.; Schmitz, L.; Sesnic, S.; Takahashi, H.; Talvard, M.; Tighe, W.; Tynan, G.; von Goeler, S.; Woskov, P.; Zolfaghari, A.

1995-01-01

Application of Ion Bernstein Wave Heating (IBWH) into the Princeton Beta Experiment-Modification (PBX-M) [Phys. Fluids B 2, 1271 (1990)] tokamak stabilizes sawtooth oscillations and generates peaked density profiles. A transport barrier, spatially correlated with the IBWH power deposition profile, is observed in the core of IBWH-assisted neutral beam injection (NBI) discharges. A precursor to the fully developed barrier is seen in the soft x-ray data during edge localized mode (ELM) activity. Sustained IBWH operation is conducive to a regime where the barrier supports large ∇n e , ∇T e , ∇ν φ , and ∇T i , delimiting the confinement zone. This regime is reminiscent of the H(high) mode, but with a confinement zone moved inward. The core region has better than H-mode confinement while the peripheral region is L(low)-mode-like. The peaked profile enhances NBI core deposition and increases nuclear reactivity. An increase in central T i results from χ i reduction (compared to the H mode) and better beam penetration. Bootstrap current fractions of up to 0.32--0.35 locally and 0.28 overall were obtained when an additional NBI burst is applied to this plasma

Characteristics of the positive ion source at reduced gas feed

Energy Technology Data Exchange (ETDEWEB)

Sharma, S. K., E-mail: sksharma@ipr.res.in; Bharathi, P.; Prahlad, V.; Patel, P. J.; Choksi, B.; Jana, M. R.; Bansal, L. K.; Qureshi, K.; Sumod, C. B.; Vadher, V.; Thakkar, D.; Gupta, L. N.; Rambabu, S.; Parmar, S.; Contractor, N.; Sahu, A. K.; Pandya, B.; Sridhar, B.; Pandya, S.; Baruah, U. K. [Institute for Plasma Research, Bhat, Gandhinagar (India)

2014-11-15

The neutral beam injector of steady state superconducting tokamak (SST1-NBI) at IPR is designed for injecting upto 1.7 MW of neutral beam (Hº, 30–55 keV) power to the tokamak plasma for heating and current drive. Operations of the positive ion source (PINI or Plug-In-Neutral-Injector) of SST1-NBI were carried out on the NBI test stand. The PINI was operated at reduced gas feed rate of 2–3 Torr l/s, without using the high speed cryo pumps. Experiments were conducted to achieve a stable beam extraction by optimizing operational parameters namely, the arc current (120–300 A), acceleration voltage (16–40 kV), and a suitable control sequence. The beam divergence, power density profiles, and species fractions (H{sup +}:H{sub 2}{sup +}:H{sub 3}{sup +}) were measured by using the diagnostics such as thermal calorimetry, infrared thermography, and Doppler shift spectroscopy. The maximum extracted beam current was about 18 A. A further increase of beam current was found to be limited by the amount of gas feed rate to the ion source.

Divertor pumping system with NBI cryopump for JT-60

International Nuclear Information System (INIS)

Akino, Noboru; Kuriyama, Masaaki; Ohga, Tokumichi; Seki, Hiroshi; Tanai, Yutaka

1998-08-01

The pumping system for JT-60 W-shape divertor with the NBI cryopump have been developed. The pumping speed achieved in the divertor region was 13-15 m 3 /s for deuterium gas with three units of the NBI cryopumps. In a simulation experiment of helium ash exhaust through the divertor, pumping of a mixed gas of helium and deuterium has been demonstrated using the NBI cryosorption pumps covered with an argon condensed layer. Control of neutral particle pressure in the divertor region became possible by having remodeled an aperture of the existing fast shutter, which is installed between the JT-60 vacuum vessel and NBI beam-line, to be regulated. (author)

Impacts of the Shine Through neutrals on the Vacuum Vessel of TJ-II during NBI; Impactos de los Neutros de Shine Through en la Camara de Vacio del TJ-II durante NBI

Energy Technology Data Exchange (ETDEWEB)

Guasp, J.; Liniers, M.

1995-07-01

A numerical analysis of the impact patterns on the Vacuum Vessel produced by Shine Through neutrals during the tangential balanced NBI in TJ-II Helical Axis Stellarator has been done. The results show two main concentrations. The first one the circular part of the Hard Core, near the zone of closest approach of the beam. The second one, the most important, around the beam exit, on the border between the plate of the HC cover and the sector wall. As expected, the Shine Through loads decrease strongly with plasma density, predominating at low density at NBI start, decreasing quickly when density increases and increasing slightly with the beam energy. No overlapping with lost fast ions impacts is observed, that, in addition, show an opposite behaviour with density. (Author) 3 refs.

Development of a RF source for ITER NBI: First results with D- operation

International Nuclear Information System (INIS)

Speth, E.; Falter, H.D.; Franzen, P.; Heinemann, B.; Bandyopadhyay, M.; Fantz, U.; Kraus, W.; McNeely, P.; Riedl, R.; Tanga, A.; Wilhelm, R.

2005-01-01

As an alternative for ITER NBI a RF source is being developed at IPP, Garching. This paper reports the first results with deuterium extracted from a restricted extraction area and accelerated to about 22 KeV. A current density of 150 A/m 2 (calorimetric) of D - ions has been reached so far in a Cs-seeded discharge with an electron/ion ration of ≤1. The effect of the magnetic filter field on the yield and the electron suppression and possible limitations/improvements are discussed. The neutron production rate is about a factor 40 lower than expected from positive ions. Possible reasons for this are discussed

Impacts of the Shine Through neutrals on the Vacuum Vessel of TJ-II during NBI

International Nuclear Information System (INIS)

Guasp, J.; Liniers, M.

1995-09-01

A numerical analysis of the impact patterns on the Vacuum Vessel produced by Shine through neutrals during the tangential balanced NBI in TJ-II Helical Axis Stellarator has been done. The results show two main concentrations. The first one the circular part of the Hard Core, near the zone of closest approach of the beam. The second one, the most important, around the beam exit, on the border between the plate of the HC cover and the sector wall. As expected, the Shine through loads decrease strongly with plasma density, predominating at low density at NBI start, decreasing quickly when density increases and increasing slightly with the beam energy. No overlapping with lost fast ions impacts is observed, that, in addition, show an opposite behaviour with density

Long-pulse operation of an intense negative ion source

Energy Technology Data Exchange (ETDEWEB)

Takeiri, Yasuhiko; Osakabe, Masaki; Tsumori, Katsuyoshi; Kaneko, Osamu; Oka, Yoshihide; Asano, Eiji; Kawamoto, Toshikazu; Akiyama, Ryuichi; Kuroda, Tsutomu [National Inst. for Fusion Science, Nagoya (Japan)

1997-02-01

In the National Institute for Fusion Science, as the heating system for the Large Helical Device (LHD), the negative ion NBI system of 20 MW incident power has been planned, and the development of a large current, large size negative ion source has been advanced. Based on the results obtained so far, the design of the LHD-NBI system was reconsidered, and the specification of the actual negative ion source was decided as 180 KeV-40A. This time, the grounding electrode with heightened heat removal capacity was made, and the long pulse operation was attempted, therefore, its results are reported. The structure of the external magnetic filter type large negative ion source used for the long pulse experiment is explained. In order to form the negative ion beam of long pulses, it is necessary to form stable are discharge plasma for long time, and variable resistors were attached to the output side of arc power sources of respective filament systems. By adjusting the resistors, uniform are discharge was able to be caused for longer than 10 s stably. The results of the long pulse experiment are reported. The dependence of the characteristics of negative ion beam on plasma electrode temperature was small, and the change of the characteristics of negative ion beam due to beam pulse width was not observed. (K.I.)

Power supply system for KSTAR neutral beam injector

Energy Technology Data Exchange (ETDEWEB)

Cho, W., E-mail: franciscocho@nfri.re.kr; Bae, Y.S.; Han, W.S.; Jeong, J.H.; Kim, J.S.; Park, H.T.; Yang, H.L.; Oh, Y.K.; Kwak, J.G.

2015-10-15

Highlights: • The power supply system in KSTAR NBI consists of DC power supplies for ion source. • For operation NBI, DC High Voltage based on the low voltage transformer with chopper. • The surge absorber near the ion source limit the energy deposited to accelerator grid. - Abstract: The power supply system in KSTAR neutral beam injector consists of low voltage and high current DC power supplies for plasma generator of ion source and high voltage and high current DC power supply for accelerator grid system. The arc discharge is initiated by an arc power supply supplying the arc voltage between the chamber wall and 12 filaments which are heated by individual filament power supply. The negative output of arc power supply is common to each positive output of 12 filament power supplies. To interrupt the arc discharging for the fault condition of the arc current unbalance, DCCT current monitor is placed at the positive output cable of the filament power supply. The plasma grid (G1) power supply has the maximum capability of 120 kV/70 A which consists of low voltage regulator with IGBT-switched chopper array system for the voltage control in unit of 600 V and the high voltage rectified transformers to supply DC voltage of 20 kV, 30 kV, and 50 kV. The output voltage of the G1 power supply is also connected to the input of the voltage divider system which supplies the gradient voltage to the gradient grid (G2) in the range of 80–90% of G1 voltage by changing tap of winding resistors in unit of 1%. The charged G1 voltage is turned on and off by the high voltage switch (HVS) system consisting of MOSFET fast semiconductor switches which can immediately be opened less than 1 μs when the ion source grid breakdown occurs. The decelerating grid (G3) power supply is inverter system using capacitor-charge power supply to supply maximum −5 kV/5 A. The important component in power supply system is the surge absorber near the ion source to limit the arc energy deposited to

Power supply system for KSTAR neutral beam injector

International Nuclear Information System (INIS)

Cho, W.; Bae, Y.S.; Han, W.S.; Jeong, J.H.; Kim, J.S.; Park, H.T.; Yang, H.L.; Oh, Y.K.; Kwak, J.G.

2015-01-01

Highlights: • The power supply system in KSTAR NBI consists of DC power supplies for ion source. • For operation NBI, DC High Voltage based on the low voltage transformer with chopper. • The surge absorber near the ion source limit the energy deposited to accelerator grid. - Abstract: The power supply system in KSTAR neutral beam injector consists of low voltage and high current DC power supplies for plasma generator of ion source and high voltage and high current DC power supply for accelerator grid system. The arc discharge is initiated by an arc power supply supplying the arc voltage between the chamber wall and 12 filaments which are heated by individual filament power supply. The negative output of arc power supply is common to each positive output of 12 filament power supplies. To interrupt the arc discharging for the fault condition of the arc current unbalance, DCCT current monitor is placed at the positive output cable of the filament power supply. The plasma grid (G1) power supply has the maximum capability of 120 kV/70 A which consists of low voltage regulator with IGBT-switched chopper array system for the voltage control in unit of 600 V and the high voltage rectified transformers to supply DC voltage of 20 kV, 30 kV, and 50 kV. The output voltage of the G1 power supply is also connected to the input of the voltage divider system which supplies the gradient voltage to the gradient grid (G2) in the range of 80–90% of G1 voltage by changing tap of winding resistors in unit of 1%. The charged G1 voltage is turned on and off by the high voltage switch (HVS) system consisting of MOSFET fast semiconductor switches which can immediately be opened less than 1 μs when the ion source grid breakdown occurs. The decelerating grid (G3) power supply is inverter system using capacitor-charge power supply to supply maximum −5 kV/5 A. The important component in power supply system is the surge absorber near the ion source to limit the arc energy deposited to

Prompt loss of beam ions in KSTAR plasmas

Directory of Open Access Journals (Sweden)

Jun Young Kim

2016-10-01

Full Text Available For a toroidal plasma facility to realize fusion energy, researching the transport of fast ions is important not only due to its close relation to the heating and current drive efficiencies but also to determine the heat load on the plasma-facing components. We present a theoretical analysis and orbit simulation for the origin of lost fast-ions during neutral beam injection (NBI heating in Korea Superconducting Tokamak Advanced Research (KSTAR device. We adopted a two-dimensional phase diagram of the toroidal momentum and magnetic moment and describe detectable momentums at the fast-ion loss detector (FILD position as a quadratic line. This simple method was used to model birth ions deposited by NBI and drawn as points in the momentum phase space. A Lorentz orbit code was used to calculate the fast-ion orbits and present the prompt loss characteristics of the KSTAR NBI. The scrape-off layer deposition of fast ions produces a significant prompt loss, and the model and experimental results closely agreed on the pitch-angle range of the NBI prompt loss. Our approach can provide wall load information from the fast ion loss.

National Bridge Inventory System (NBI)

Data.gov (United States)

Department of Transportation — The NBI System is the collection of bridge inspection information and costs associated with bridge replacements of structurally deficient bridges on and off the NHS....

Investigations on Cs-free alternative materials for negative hydrogen ion formation

Energy Technology Data Exchange (ETDEWEB)

Kurutz, Uwe

2017-01-19

Neutral beam injection (NBI) represents a main auxiliary heating and current drive system for thermonuclear fusion devices. For ITER, a total heating power of up to 33 MW will be delivered for up to one hour pulses at particle energies of up to 1 MeV by two NBI systems. The respective ion sources will therefore have to allow for the extraction and acceleration of negative hydrogen ions at a current density of 200 A/m{sup 2} from a low pressure low temperature hydrogen plasma. Also for the succeeding demonstration reactor DEMO the application of NBI is currently discussed. Respective systems will, however, have to fulfil even higher demands, like higher powers (up to 135 MW), longer pulse lengths (2 h or even cw operation), and more restrictive constrains regarding the reliability and stability. Today efficient NBI negative hydrogen ion sources are based mainly on the conversion of positive hydrogen ions and/or hydrogen atoms at a grid surface coated with caesium. Cs is used for reducing the grid's work function which significantly enhances the particle conversion probability. However, the alkali metal is chemically very reactive and easily forms compounds with residual gas impurities. Furthermore, complex redistribution dynamics of the deposited Cs layer is given. This inherently links the application of Cs with a temporal and spatial non-stability of the negative ion yield, which contradicts the required reliability of a DEMO NBI system. Thus, for DEMO, Cs-free alternative materials for negative ion formation are investigated within this work at a flexible laboratory experiment. An ECR discharge is used which provides comparable parameters (pressure, densities, particle fluxes and -energies) to the NBI ion sources. Negative ion formation is measured above different material samples via laser photodetachment together with global plasma parameters using a Langmuir probe and optical emission spectroscopy. The plasma parameters are used for modelling the

Investigations on Cs-free alternative materials for negative hydrogen ion formation

International Nuclear Information System (INIS)

Kurutz, Uwe

2017-01-01

Neutral beam injection (NBI) represents a main auxiliary heating and current drive system for thermonuclear fusion devices. For ITER, a total heating power of up to 33 MW will be delivered for up to one hour pulses at particle energies of up to 1 MeV by two NBI systems. The respective ion sources will therefore have to allow for the extraction and acceleration of negative hydrogen ions at a current density of 200 A/m 2 from a low pressure low temperature hydrogen plasma. Also for the succeeding demonstration reactor DEMO the application of NBI is currently discussed. Respective systems will, however, have to fulfil even higher demands, like higher powers (up to 135 MW), longer pulse lengths (2 h or even cw operation), and more restrictive constrains regarding the reliability and stability. Today efficient NBI negative hydrogen ion sources are based mainly on the conversion of positive hydrogen ions and/or hydrogen atoms at a grid surface coated with caesium. Cs is used for reducing the grid's work function which significantly enhances the particle conversion probability. However, the alkali metal is chemically very reactive and easily forms compounds with residual gas impurities. Furthermore, complex redistribution dynamics of the deposited Cs layer is given. This inherently links the application of Cs with a temporal and spatial non-stability of the negative ion yield, which contradicts the required reliability of a DEMO NBI system. Thus, for DEMO, Cs-free alternative materials for negative ion formation are investigated within this work at a flexible laboratory experiment. An ECR discharge is used which provides comparable parameters (pressure, densities, particle fluxes and -energies) to the NBI ion sources. Negative ion formation is measured above different material samples via laser photodetachment together with global plasma parameters using a Langmuir probe and optical emission spectroscopy. The plasma parameters are used for modelling the inherently

National Bridge Inventory (NBI) Bridges

Data.gov (United States)

Department of Homeland Security — The NBI is a collection of information (database) describing the more than 600,000 of the Nation's bridges located on public roads, including Interstate Highways,...

Fast Ion Collective Thomson Scattering Diagnostic for ITER

DEFF Research Database (Denmark)

Korsholm, Søren Bang; Bindslev, Henrik; Furtula, Vedran

2008-01-01

In the era of high power and burning plasma fusion experiments with significant populations of fast particles, the diagnosis of fast ion dynamics becomes an important topic. In ITER, populations of fast ions due to ICRH and NBI, as well as fusion born alphas will carry a significant fraction...... of mock-up measurements have brought the design towards a four mirror quasi-optical solution. The development as well as the present design will be presented....

Impacts of the Shine Through neutrals on the Vacuum Vessel of TJ-II during NBI

International Nuclear Information System (INIS)

Guasp, J.; Liniers, M.

1995-01-01

A numerical analysis of the impact patterns on the Vacuum Vessel produced by Shine Through neutrals during the tangential balanced NBI in TJ-II Helical Axis Stellarator has been done. The results show two main concentrations. The first one the circular part of the Hard Core, near the zone of closest approach of the beam. The second one, the most important, around the beam exit, on the border between the plate of the HC cover and the sector wall. As expected, the Shine Through loads decrease strongly with plasma density, predominating at low density at NBI start, decreasing quickly when density increases and increasing slightly with the beam energy. No overlapping with lost fast ions impacts is observed, that, in addition, show an opposite behaviour with density. (Author) 3 refs

Development of bucket ion source for JFT-2M neutral beam injector

International Nuclear Information System (INIS)

Shibata, Takatoshi; Kazawa, Minoru; Yokoyama, Kenji; Shibuya, Toshihiro; Honda, Atsushi; Shiina, Tomio

1987-02-01

Detailed description is given of a new Bucket Ion Source for NBI heating experiments on JFT-2M. The source is designed to achieve the high proton ratio (∼ 80 %) as well as high power. Results of the performance test is also given. (author)

Analysis of ferromagnetic shielding of the ITER NBI

International Nuclear Information System (INIS)

Roccella, M.; Lucca, F.; Roccella, R.; Cocilovo, V.; Ramogida, G.; Portone, A.; Tanga, A.; Formisano, A.; Martone, R.

2006-01-01

In ITER two heating and one diagnostic Neutral Beam Injectors (NBIs) are foreseen [P. L. Mondino et al., ''ITER neutral beam system '', Nucl. Fus., vol. 40, p. 501 (2000)]. Inside these components there are very stringent limits on the magnetic field (the flux density must be below some Gauss (G) along the ion path and below 20 G in the neutralizing region). To achieve these performances in an environment with high stray field due to the plasma and the poloidal field coils, both passive and active shielding systems are foreseen. The present design of the Magnetic Field Reduction System (MFRS) is made of seven active coils and of a box surrounding the NBI region, consisting of ferromagnetic plates 15 cm thick. The electromagnetic analysis of the effectiveness of these shields has been performed by a full 3D FEM model using the ANSYS code. To perform the FEM modeling of the component special care has been used to face the particular geometrical features of the component (a box of about 15 x 5 x 5 m vs. a ferromagnetic layer of only 15 cm thick). To insert an adequate number of FEM elements (at least 5) in the thickness of the ferromagnetic layer, without a prohibitive increase in the total FEM elements number, a particular modeling approach (a sort of '' Chinese boxes '' technique) has been developed. Due to this technique the FEM model enclosing the ferromagnetic box results completely independent on the fine FEM structure inside the shielding layer. It has been even possible, using this technique, introducing a thin (below 1 cm thick) slot all through the shielding plates, without perturbing the rest of the model. This slot has been used to analyze the effects of possible manufacturing lacks on the residual magnetic field inside the component. This technique has allowed the use of only structured meshes made by brick elements, much more accurate than the tetra elements, needed in the usual free meshing techniques. To have the possibility of changing the shielding

Recent Developments in High-Harmonic Fast Wave Physics in NSTX

International Nuclear Information System (INIS)

LeBlanc, B.P.; Bell, R.E.; Bonoli, P.; Harvey, R.; Heidbrink, W.W.; Hosea, J.C.; Kaye, S.M.; Liu, D.; Maingi, R.; Medley, S.S.; Ono, M.; Podesta, M.; Phillips, C.K.; Ryan, P.M.; Roquemore, A.L.; Taylor, G.; Wilson, J.R.

2010-01-01

Understanding the interaction between ion cyclotron range of frequency (ICRF) fast waves and the fast-ions created by neutral beam injection (NBI) is critical for future devices such as ITER, which rely on a combination ICRF and NBI. Experiments in NSTX which use 30 MHz High-Harmonic Fast-Wave (HHFW) ICRF and NBI heating show a competition between electron heating via Landau damping and transit-time magnetic pumping, and radio-frequency wave acceleration of NBI generated fast ions. Understanding and mitigating some of the power loss mechanisms outside the last closed flux surface (LCFS) has resulted in improved HHFW heating inside the LCFS. Nevertheless a significant fraction of the HHFW power is diverted away from the enclosed plasma. Part of this power is observed locally on the divertor. Experimental observations point toward the radio-frequency (RF) excitation of surface waves, which disperse wave power outside the LCFS, as a leading loss mechanism. Lithium coatings lower the density at the antenna, thereby moving the critical density for perpendicular fast-wave propagation away from the antenna and surrounding material surfaces. Visible and infrared imaging reveal flows of RF power along open field lines into the divertor region. In L-mode -- low average NBI power -- conditions, the fast-ion D-alpha (FIDA) diagnostic measures a near doubling and broadening of the density profile of the upper energetic level of the fast ions concurrent with the presence of HHFW power launched with k// = -8m-1. We are able to heat NBI-induced H-mode plasmas with HHFW. The captured power is expected to be split between absorption by the electrons and absorption by the fast ions, based on TORIC calculation. In the case discussed here the Te increases over the whole profile when ∼2MW of HHFW power with antenna k// = 13m-1 is applied after the H-mode transition. But somewhat unexpectedly fast-ion diagnostics do not observe a change between the HHFW heated NBI discharge and the

Operation and Development on the Positive-Ion Based Neutral Beam Injection System for JT-60 and JT-60U

International Nuclear Information System (INIS)

Kuriyama, M.; Akino, N.; Ebisawa, N.; Honda, A.; Itoh, T.; Kawai, M.; Mogaki, K.; Ohga, T.; Oohara, H.; Umeda, N.; Usui, K.; Yamamoto, M.; Yamamoto, T.; Matsuoka, M.

2002-01-01

The positive-ion based neutral beam injection (NBI) system for JT-60, which consists of 14 beamline units and has a beam energy of 70 to 100 keV, started operation in 1986 with hydrogen beams and injected a neutral beam power of 27 MW at 75 keV into the JT-60 plasma. In 1991, the NBI system was modified to be able to handle deuterium beams as part of the JT-60 upgrade modification. After executing some research and developments, deuterium beams of 40 MW at 95 keV were injected in 1996. As a result, NBI has contributed to the achievement of the highest performance plasmas, a DT-equivalent fusion power gain of 1.25 and a fusion triple product of 1.55 x 10 21 keVs/m 3 , in the world on JT-60U

Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering

International Nuclear Information System (INIS)

Bindslev, H; Nielsen, S K; Porte, L; Hoekzema, J A; Korsholm, S B; Meo, F; Michelsen, P K; Michelsen, S; Oosterbeek, J W; Tsakadze, E L; Westerhof, E; Woskov, P

2007-01-01

The dynamics of fast ion populations in the TEXTOR tokamak are measured by collective Thomson scattering of millimetre wave radiation generated by a gyrotron operated at 110 GHz and 100-150 kW. Temporal evolution of the energetic ion velocity distribution at switch on of neutral beam injection (NBI) and the slowdown after switch off of NBI are measured. The turn on phase of the NBI has, furthermore, been measured in plasmas with a range of electron densities and temperatures. All of these measurements are shown to be in good agreement with simple Fokker-Planck modelling. Bulk ion rotation velocity is also measured

Fast ions and momentum transport in JET tokamak plasmas

International Nuclear Information System (INIS)

Salmi, A.

2012-01-01

Fast ions are an inseparable part of fusion plasmas. They can be generated using electromagnetic waves or injected into plasmas as neutrals to heat the bulk plasma and to drive toroidal rotation and current. In future power plants fusion born fast ions deliver the main heating into the plasma. Understanding and controlling the fast ions is of crucial importance for the operation of a power plant. Furthermore, fast ions provide ways to probe the properties of the thermal plasma and get insight of its confinement properties. In this thesis, numerical code packages are used and developed to simulate JET experiments for a range of physics issues related to fast ions. Namely, the clamping fast ion distribution at high energies with RF heating, fast ion ripple torque generation and the toroidal momentum transport properties using NBI modulation technique are investigated. Through a comparison of numerical simulations and the JET experimental data it is shown that the finite Larmor radius effects in ion cyclotron resonance heating are important and that they can prevent fast ion tail formation beyond certain energy. The identified mechanism could be used for tailoring the fast ion distribution in future experiments. Secondly, ASCOT simulations of NBI ions in a ripple field showed that most of the reduction of the toroidal rotation that has been observed in the JET enhanced ripple experiments could be attributed to fast ion ripple torque. Finally, fast ion torque calculations together with momentum transport analysis have led to the conclusion that momentum transport in not purely diffusive but that a convective component, which increases monotonically in radius, exists in a wide range of JET plasmas. Using parameter scans, the convective transport has been shown to be insensitive to collisionality and q-profile but to increase strongly against density gradient. (orig.)

Fast ions and momentum transport in JET tokamak plasmas

Energy Technology Data Exchange (ETDEWEB)

Salmi, A.

2012-07-01

Fast ions are an inseparable part of fusion plasmas. They can be generated using electromagnetic waves or injected into plasmas as neutrals to heat the bulk plasma and to drive toroidal rotation and current. In future power plants fusion born fast ions deliver the main heating into the plasma. Understanding and controlling the fast ions is of crucial importance for the operation of a power plant. Furthermore, fast ions provide ways to probe the properties of the thermal plasma and get insight of its confinement properties. In this thesis, numerical code packages are used and developed to simulate JET experiments for a range of physics issues related to fast ions. Namely, the clamping fast ion distribution at high energies with RF heating, fast ion ripple torque generation and the toroidal momentum transport properties using NBI modulation technique are investigated. Through a comparison of numerical simulations and the JET experimental data it is shown that the finite Larmor radius effects in ion cyclotron resonance heating are important and that they can prevent fast ion tail formation beyond certain energy. The identified mechanism could be used for tailoring the fast ion distribution in future experiments. Secondly, ASCOT simulations of NBI ions in a ripple field showed that most of the reduction of the toroidal rotation that has been observed in the JET enhanced ripple experiments could be attributed to fast ion ripple torque. Finally, fast ion torque calculations together with momentum transport analysis have led to the conclusion that momentum transport in not purely diffusive but that a convective component, which increases monotonically in radius, exists in a wide range of JET plasmas. Using parameter scans, the convective transport has been shown to be insensitive to collisionality and q-profile but to increase strongly against density gradient. (orig.)

The development of the radio frequency driven negative ion source for neutral beam injectors (invited)

International Nuclear Information System (INIS)

Kraus, W.; Fantz, U.; Franzen, P.; Froeschle, M.; Heinemann, B.; Riedl, R.; Wuenderlich, D.

2012-01-01

Large and powerful negative hydrogen ion sources are required for the neutral beam injection (NBI) systems of future fusion devices. Simplicity and maintenance-free operation favors RF sources, which are developed intensively at the Max-Planck-Institut fuer Plasmaphysik (IPP) since many years. The negative hydrogen ions are generated by caesium-enhanced surface conversion of atoms and positive ions on the plasma grid surface. With a small scale prototype the required high ion current density and the low fraction of co-extracted electrons at low pressure as well as stable pulses up to 1 h could be demonstrated. The modular design allows extension to large source dimensions. This has led to the decision to choose RF sources for the NBI of the international fusion reactor, ITER. As an intermediate step towards the full size ITER source at IPP, the development will be continued with a half-size source on the new ELISE testbed. This will enable to gain experience for the first time with negative hydrogen ion beams from RF sources of these dimensions.

Plasma heating: NBI ampersand RF, an introduction

International Nuclear Information System (INIS)

Koch, R.

1996-01-01

The additional heating and non-inductive current-drive methods are reviewed. First, the limitations of ohmic heating in tokamaks are examined and the motivations for using additional heating in tokamaks or other machines are discussed. Next we sketch the principles of heating by injection of fast neutrals - or Neutral Beam Injection (NBI). The principle of the injector is briefly outlined. Positive and negative ion based concepts are discussed. The remainder of the lecture focuses on the processes by which the beam transfers energy to the plasma: the ionisation and slowing-down processes. Next, I make a review of the different heating schemes based on the transfer of electromagnetic energy to the plasma. The different wave heating frequency ranges are listed and the propagation and damping peculiarities are sketched in each domain. Heating in the Alfven and lower hybrid wave domains are described in some more details. 21 refs., 9 figs., 1 tab

TRANSP modeling of minority ion sawtooth mixing in ICRF + NBI heated discharges in TFTR

International Nuclear Information System (INIS)

Goldfinger, R.C.; Batchelor, D.B.; Murakami, M.; Phillips, C.K.; Budny, R.; Hammett, G.W.; McCune, D.M.; Wilson, J.R.; Zarnstorff, M.C.

1995-01-01

Time independent code analysis indicates that the sawtooth relaxation phenomenon affects RF power deposition profiles through the mixing of fast ions. Predicted central electron heating rates are substantially above experimental values unless sawtooth relaxation is included. The PPPL time dependent transport analysis code, TRANSP, currently has a model to redistribute thermal electron and ion species, energy densities, plasma current density, and fast ions from neutral beam injection at each sawtooth event using the Kadomtsev (3) prescription. Results are presented here in which the set of models is extended to include sawtooth mixing effects on the hot ion population generated from ICRF heating. The ICRF generated hot ion distribution function, line-integral(ν parallel , ν perpendicular ), which is strongly peaked at the center before each sawtooth, is replaced throughout the sawtooth mixing volume by its volume averaged value at each sawtooth. The modified line-integral(ν parallel ,ν perpendicular ) is then used to recalculate the collisional transfer of power from the minority species to the background species. Results demonstrate that neglect of sawtooth mixing of ICRF-induced fast ions leads to prediction of faster central electron reheat rates than are measured experimentally

Faraday-cup-type lost fast ion detector on Heliotron J

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, S., E-mail: yamamoto.satoshi.6n@kyoto-u.ac.jp; Kobayashi, S.; Nagasaki, K.; Okada, H.; Minami, T.; Kado, S.; Ohshima, S.; Weir, G. M.; Konoshima, S.; Mizuuchi, T. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Ogawa, K.; Isobe, M. [National Institute for Fusion Science, National Institutes of Natural Sciences, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Darrow, D. S. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Nakamura, Y.; Ohtani, Y. [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Kemmochi, N. [National Institute for Fusion Science, National Institutes of Natural Sciences, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)

2016-11-15

A Faraday-cup type lost-fast ion probe (FLIP) has been designed and installed in Heliotron J for the purpose of the studies of interaction between fast ions and MHD instabilities. The FLIP can measure the co-going fast ions whose energy is in the range of 1.7–42.5 keV (proton) and pitch angle of 90{sup ∘}–140{sup ∘}, especially for fast ions having the injection energy of neutral beam injection (NBI). The FLIP successfully measured the re-entering passing ions and trapped lost-fast ions caused by fast-ion-driven energetic particle modes in NBI heated plasmas.

Design of remote handling equipment for the ITER NBI

Energy Technology Data Exchange (ETDEWEB)

Oka, Kiyoshi; Tada, Eisuke [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1999-08-01

The ITER machine has three Neutral Beam Injectors (NBIs) placed tangential to the plasma at a minimum radius of 6.25 m. During operation, neutrons produced by the D-T reactions will irradiate the NBI structure and it will become radioactive. Radiation levels will be such that all subsequent maintenance of the NBIs must be carried out remotely. The presence of tritium and possibly radioactive dust requires that precautions be taken during maintenance to prevent the escape of these contaminants beyond the prescribed boundaries. The scope of this task is both the development of remote maintenance procedures and the design of the remote handling equipment to handle the NBIs. This report describes the design of remote handling tools for the ion source and its filaments, transfer cask, maintenance time, manufacturing schedule and cost estimation. (author)

NBI - plasma vaporization hybrid approach in bladder cancer endoscopic management.

Science.gov (United States)

Stănescu, F; Geavlete, B; Georgescu, D; Jecu, M; Moldoveanu, C; Adou, L; Bulai, C; Ene, C; Geavlete, P

2014-06-15

A prospective study was performed aiming to evaluate the surgical efficacy, perioperative safety profile, diagnostic accuracy and medium term results of a multi-modal approach consisting in narrow band imaging (NBI) cystoscopy and bipolar plasma vaporization (BPV) when compared to the standard protocol represented by white light cystoscopy (WLC) and transurethral resection of bladder tumors (TURBT). A total of 260 patients with apparently at least one bladder tumor over 3 cm were included in the trial. In the first group, 130 patients underwent conventional and NBI cystoscopy followed by BPV, while in a similar number of cases of the second arm, classical WLC and TURBT were applied. In all non-muscle invasive bladder tumors' (NMIBT) pathologically confirmed cases, standard monopolar Re-TUR was performed at 4-6 weeks after the initial intervention, followed by one year' BCG immunotherapy. The follow-up protocol included abdominal ultrasound, urinary cytology and WLC, performed every 3 months for a period of 2 years. The obturator nerve stimulation, bladder wall perforation, mean hemoglobin level drop, postoperative bleeding, catheterization period and hospital stay were significantly reduced for the plasma vaporization technique by comparison to conventional resection. Concerning tumoral detection, the present data confirmed the NBI superiority when compared to standard WLC regardless of tumor stage (95.3% vs. 65.1% for CIS, 93.3% vs. 82.2% for pTa, 97.4% vs. 94% for pT1, 95% vs. 84.2% overall). During standard Re-TUR the overall (6.3% versus 17.4%) and primary site (3.6% versus 12.8%) residual tumors' rates were significantly lower for the NBI-BPV group. The 1 (7.2% versus 18.3%) and 2 (11.5% versus 25.8%) years' recurrence rates were substantially lower for the combined approach. NBI cystoscopy significantly improved diagnostic accuracy, while bipolar technology showed a higher surgical efficiency, lower morbidity and faster postoperative recovery. The combined

Langmuir probe studies on a RF ion source for NBI

International Nuclear Information System (INIS)

McNeely, P.; Heineman, B.; Kraus, W.; Riedl, R.; Speth, E.; Vollmer, O.

2001-01-01

IPP Garching has been developing a RF ion source for H - production. In order to improve the data quality a new scanning probe system with passive RF compensation has been installed on the Type VI ion source on the BATMAN test stand. Using this probe, measurements have been carried out to study changes to the plasma parameters (electron density, electron temperature, and plasma potential) due to variation in the source operating conditions. The data were collected at a source pressure of 0.5 Pa and with 60±5 kW applied RF power. Presented are some of the results of these measurements, focusing on the effect of: argon seeding, addition of Cs to the source, and the newly added Faraday screen. The electron density behaves in a fashion that agrees with the theory of ambipolar diffusion. Typically there is little change to the average electron energy observed regardless of which effect is considered. The plasma potential shows the most significant changes with external source conditions, both in value for all cases and shape when the Faraday screen was added

Ion thermal conductivity and convective energy transport in JET hot-ion regimes and H-modes

International Nuclear Information System (INIS)

Tibone, F.; Balet, B.; Cordey, J.G.

1989-01-01

Local transport in a recent series of JET experiments has been studied using interpretive codes. Auxiliary heating, mainly via neutral beam injection, was applied on low-density target plasmas confined in the double-null X-point configuration. This has produced two-component plasmas with high ion temperature and neutron yield and, above a threshold density, H-modes characterised by peak density and power deposition profiles. H-mode confinement was also obtained for the first time with 25 MW auxiliary power, of which 10 MW was from ion cyclotron resonance heating. We have used profile measurements of electron temperature T e from electron cyclotron emission and LIDAR Thomson scattering, ion temperature T i from charge-exchange recombination spectroscopy (during NBI), electron density n e from LIDAR and Abel-inverted interferometer measurements. Only sparse information is, however, available to date concerning radial profiles of effective ionic charge and radiation losses. Deuterium depletion due to high impurity levels is an important effect in these discharges, and our interpretation of thermal ion energy content, neutron yield and ion particle fluxes needs to be confirmed using measured Z eff -profiles. (author) 4 refs., 4 figs

Development of the High Current Ion Source for Neutral Beam Injection

Energy Technology Data Exchange (ETDEWEB)

Lee, Hun Ju; Kim, S. H.; Jang, D. H. [Jae Ju University, Jaeju (Korea, Republic of)

1997-08-01

The scope of the 1st year research is to design an 140keV deuterium ion source which has a beam current of 30-40A. According to the collected data, the model of an ion source for NBI of KSTAR was established. The negative ion source, which has good neutralization effecting in high energy, was selected. To generate a plasma, the thoriated tungsten filament was adopted. To increase the efficiency of plasma, the multi cusp type magnetic field was attached. The magnetic field was calculated by POISSON code. The extraction structure was designed with EGUN code, to extract the high quality ion beam. The design of a high current ion source for NBI was carried out. To develop the high current ion source with the high operational stability and the long lifetime, the parameters including an arc current, gas pressure and extraction voltage should be optimized. If designed ion source would be fabricated, its parameters could be optimized experimentally. Through the optimization of the ion source parameter, the core technology for NBI is established and the experiment of current drive in the fusion device can be performed. This technology also can be applied to the synthesis of new material and semiconductor industry. 18 refs., 11 tabs., 19 figs. (author)

Protections Against Grid Breakdowns in the ITER Neutral Beam Injector Power Supplies

International Nuclear Information System (INIS)

Bigi, M.; Toigo, V.; Zanotto, L.

2006-01-01

The ITER Neutral Beam Injector (NBI) is designed to deliver 16.5 MW of additional heating power to the plasma, accelerating negative ions up to -1 MV with a current up to 40 A. Two main power supplies are foreseen to feed the system: the Acceleration Grid Power Supply (AGPS), which provides power to the acceleration grids, and the Ion Source Power Supply (ISPS), devoted to supplying the ion source components. For the accelerator, two different concepts are under investigation: the MAMuG (Multiple Aperture, Multiple Gap) and the SINGAP (SINgle Aperture). During operation of the NBI, the breakdown of the acceleration grids will occur regularly; as a consequence the AGPS is expected to experience frequent load short-circuits during a pulse. For each grid breakdown, energy and current peaks are delivered from the power supply systems that could damage the grids, if not limited. In previous NBI, rated for a lower accelerating voltage, the protection system in case of grid breakdowns was based on dc circuit breakers able to quickly disconnect the power supply from the grids. In the ITER case, a similar solution is not feasible, as the voltage level is too high for present dc breaker technology. Therefore, the protection strategy has to rely on fast switch-off of the power supplies, on the optimisation of the filter elements and core snubbers placed downstream the AGPS and on the introduction of additional passive elements. However, achieving a satisfactory protection against grid breakdowns is a challenging task, as the optimisation of each single provision can result in drawbacks for other aspects of the design; for instance, the optimisation of the filter elements, obtained by reducing the filter capacitance, produces an increase of the output voltage ripple. Therefore, the design of the protections must be carried out considering all the relevant aspects of the specifications, also those that are not strictly related to the limitations of the current peaks and energy

Bulk Ion Heating with ICRF Waves in Tokamaks

DEFF Research Database (Denmark)

Mantsinen, M. J.; Bilato, R.; Bobkov, V. V.

2015-01-01

Heating with ICRF waves is a well-established method on present-day tokamaks and one of the heating systems foreseen for ITER. However, further work is still needed to test and optimize its performance in fusion devices with metallic high-Z plasma facing components (PFCs) in preparation of ITER...... when 3 MW of ICRF power tuned to the central 3He ion cyclotron resonance was added to 4.5 MW of deuterium NBI. The radial gradient of the Ti profile reached locally values up to about 50 keV/m and the normalized logarithmic ion temperature gradients R/LTi of about 20, which are unusually large for AUG...

Modelling of caesium dynamics in the negative ion sources at BATMAN and ELISE

Science.gov (United States)

Mimo, A.; Wimmer, C.; Wünderlich, D.; Fantz, U.

2017-08-01

The knowledge of Cs dynamics in negative hydrogen ion sources is a primary issue to achieve the ITER requirements for the Neutral Beam Injection (NBI) systems, i.e. one hour operation with an accelerated ion current of 40 A of D- and a ratio between negative ions and co-extracted electrons below one. Production of negative ions is mostly achieved by conversion of hydrogen/deuterium atoms on a converter surface, which is caesiated in order to reduce the work function and increase the conversion efficiency. The understanding of the Cs transport and redistribution mechanism inside the source is necessary for the achievement of high performances. Cs dynamics was therefore investigated by means of numerical simulations performed with the Monte Carlo transport code CsFlow3D. Simulations of the prototype source (1/8 of the ITER NBI source size) have shown that the plasma distribution inside the source has the major effect on Cs dynamics during the pulse: asymmetry of the plasma parameters leads to asymmetry in Cs distribution in front of the plasma grid. The simulated time traces and the general simulation results are in agreement with the experimental measurements. Simulations performed for the ELISE testbed (half of the ITER NBI source size) have shown an effect of the vacuum phase time on the amount and stability of Cs during the pulse. The sputtering of Cs due to back-streaming ions was reproduced by the simulations and it is in agreement with the experimental observation: this can become a critical issue during long pulses, especially in case of continuous extraction as foreseen for ITER. These results and the acquired knowledge of Cs dynamics will be useful to have a better management of Cs and thus to reduce its consumption, in the direction of the demonstration fusion power plant DEMO.

Design of Timing Synchronization Software on EAST-NBI

International Nuclear Information System (INIS)

Zhao Yuanzhe; Hu Chundong; Sheng Peng; Zhang Xiaodan

2013-01-01

To ensure the uniqueness and recognition of data and make it easy to analyze and process the data of all subsystems of the neutral beam injector (NBI), it is required that all subsystems have a unified system time. In this paper, the timing synchronization software is presented which is related to many kinds of technologies, such as shared memory, multithreading, TCP protocol and so on. Shared memory helps the server save the information of clients and system time, multithreading can deal with different clients with different threads, the server works under Linux operating system, the client works under Linux operating system and Windows operating system. With the help of this design, synchronization of all subsystems can be achieved in less than one second, and this accuracy is enough for the NBI system and the reliability of data is thus ensured. (fusion engineering)

Turbulent transport stabilization by ICRH minority fast ions in low rotating JET ILW L-mode plasmas

Science.gov (United States)

Bonanomi, N.; Mantica, P.; Di Siena, A.; Delabie, E.; Giroud, C.; Johnson, T.; Lerche, E.; Menmuir, S.; Tsalas, M.; Van Eester, D.; Contributors, JET

2018-05-01

The first experimental demonstration that fast ion induced stabilization of thermal turbulent transport takes place also at low values of plasma toroidal rotation has been obtained in JET ILW (ITER-like wall) L-mode plasmas with high (3He)-D ICRH (ion cyclotron resonance heating) power. A reduction of the gyro-Bohm normalized ion heat flux and higher values of the normalized ion temperature gradient have been observed at high ICRH power and low NBI (neutral beam injection) power and plasma rotation. Gyrokinetic simulations indicate that ITG (ion temperature gradient) turbulence stabilization induced by the presence of high-energetic 3He ions is the key mechanism in order to explain the experimental observations. Two main mechanisms have been identified to be responsible for the turbulence stabilization: a linear electrostatic wave-fast particle resonance mechanism and a nonlinear electromagnetic mechanism. The dependence of the stabilization on the 3He distribution function has also been studied.

Phase I Development of Neutral Beam Injector Solid-State Power System

Science.gov (United States)

Prager, James; Ziemba, Timothy; Miller, Kenneth E.; Slobodov, Ilia; Anderson, Seth

2017-10-01

Neutral beam injection (NBI) is an important tool for plasma heating, current drive and a diagnostic at fusion science experiments around the United States, including tokamaks, validation platform experiments, and privately funded fusion concepts. Currently, there are no vendors in the United States for NBI power systems. Eagle Harbor Technologies (EHT), Inc. is developing a new power system for NBI that takes advantage of the latest developments in solid-state switching. EHT has developed a resonant converter that can be scaled to the power levels required for NBI at small-scale validation platform experiments like the Lithium Tokamak Experiment. This power system can be used to modulate the NBI voltages over the course of a plasma shot, which can lead to improved control over the plasma. EHT will present initial modeling used to design this system as well as experimental data showing operation at 15 kV and 40 A for 10 ms into a test load. With support of DOE SBIR.

Design of neutral beam injection power supplies for ITER

International Nuclear Information System (INIS)

Watanabe, Kazuhiro; Okumura, Yoshikazu; Ono, Youichi; Tanaka, Masanobu

2000-03-01

Design study on a power supply system for the ITER neutral beam injector(NBI) has been performed. Circuits of converter/inverter system and other components of the acceleration power supply whose capacity is 1 MV, 45 A have been designed in detail. Performance of the negative ion production power supplies such as an arc and an extraction power supplies was investigated using the EMTDC code. It was confirmed that ripples of 0.34%p-p for the extraction power supply and 1.7%p-p for the arc power supply are small enough. It was also confirmed that an energy input to a negative ion generator from the arc power supply at an arcing can be suppressed smaller than 8 J. The extraction power supply was designed to suppress the energy input lower than 13 J at the breakdown in the extractor. These performances satisfy the required specification of the power supply system. (author)

Fast-ion dynamics in the TEXTOR tokamak measured by collective Thomson scattering

DEFF Research Database (Denmark)

Bindslev, Henrik; Nielsen, Stefan Kragh; Porte, L.

2007-01-01

) and the slowdown after switch off of NBI are measured. The turn on phase of the NBI has, furthermore, been measured in plasmas with a range of electron densities and temperatures. All of these measurements are shown to be in good agreement with simple Fokker-Planck modelling. Bulk ion rotation velocity is also...

Role of radial electric field in LH transition triggered by counter-NBI at low plasma density in the TUMAN-3M tokamak

International Nuclear Information System (INIS)

Tukachinsky, A.S.; Askinazi, L.G.; Chernyshev, F.V. and others; Krupnik, L.I.; Rushkevich, A.A.

2008-01-01

Threshold power needed to attain H-mode in a tokamak is a critical parameter for designing of future devices and in particular fusion reactor ITER [1]. According to commonly accepted scaling [2] the threshold power P t hr increases with average density n e when the density exceeds some n em in at which P t hr is minimal. An increase in the P t hr towards low density was observed in many experiments [3-6], prevents the transition at lower n e as well. Physics of the threshold power increase at low ne is not well understood. Since the radial electric field E r and E r xB sheared flow play important roles in the LH transition one could expect these quantities effect the low n-bar e transitions. Toroidal rotation and radial electric field generation during counter-NBI have been studied in [7] and recently reconsidered theoretically in [8]. Thus, motivation for the presented study is to analyze effect of counter-NBI on the LH transition at low density

High power neutral beam injection in LHD

International Nuclear Information System (INIS)

Tsumori, K.; Takeiri, Y.; Nagaoka, K.

2005-01-01

The results of high power injection with a neutral beam injection (NBI) system for the large helical device (LHD) are reported. The system consists of three beam-lines, and two hydrogen negative ion (H - ion) sources are installed in each beam-line. In order to improve the injection power, the new beam accelerator with multi-slot grounded grid (MSGG) has been developed and applied to one of the beam-lines. Using the accelerator, the maximum powers of 5.7 MW were achieved in 2003 and 2004, and the energy of 189 keV reached at maximum. The power and energy exceeded the design values of the individual beam-line for LHD. The other beam-lines also increased their injection power up to about 4 MW, and the total injection power of 13.1 MW was achieved with three beam-lines in 2003. Although the accelerator had an advantage in high power beam injection, it involved a demerit in the beam focal condition. The disadvantage was resolved by modifying the aperture shapes of the steering grid. (author)

The role of nature-based infrastructure (NBI) in coastal resiliency planning: A literature review.

Science.gov (United States)

Saleh, Firas; Weinstein, Michael P

2016-12-01

The use of nature-based infrastructure (NBI) has attracted increasing attention in the context of protection against coastal flooding. This review is focused on NBI approaches to improve coastal resilience in the face of extreme storm events, including hurricanes. We not only consider the role of NBI as a measure to protect people and property but also in the context of other ecological goods and services provided by tidal wetlands including production of fish and shellfish. Although the results of many studies suggest that populated areas protected by coastal marshes were less likely to experience damage when exposed to the full force of storm surge, it was absolutely critical to place the role of coastal wetlands into perspective by noting that while tidal marshes can reduce wave energy from low-to-moderate-energy storms, their capacity to substantially reduce storm surge remains poorly quantified. Moreover, although tidal marshes can reduce storm surge from fast moving storms, very large expanses of habitat are needed to be most effective, and for most urban settings, there is insufficient space to rely on nature-based risk reduction strategies alone. The success of a given NBI method is also context dependent on local conditions, with potentially confounding influences from substrate characteristics, topography, near shore bathymetry, distance from the shore and other physical factors and human drivers such as development patterns. Furthermore, it is important to better understand the strengths and weaknesses of newly developed NBI projects through rigorous evaluations and characterize the local specificities of the particular built and natural environments surrounding these coastal areas. In order for the relevant science to better inform policy, and assist in land-use challenges, scientists must clearly state the likelihood of success in a particular circumstance and set of conditions. We conclude that "caution is advised" before selecting a particular NBI

Modelling third harmonic ion cyclotron acceleration of deuterium beams for JET fusion product studies experiments

DEFF Research Database (Denmark)

Schneider, M.; Johnson, T.; Dumont, R.

2016-01-01

Recent JET experiments have been dedicated to the studies of fusion reactions between deuterium (D) and Helium-3 (3He) ions using neutral beam injection (NBI) in synergy with third harmonic ion cyclotron radio-frequency heating (ICRH) of the beam. This scenario generates a fast ion deuterium tail...... enhancing DD and D3He fusion reactions. Modelling and measuring the fast deuterium tail accurately is essential for quantifying the fusion products. This paper presents the modelling of the D distribution function resulting from the NBI+ICRF heating scheme, reinforced by a comparison with dedicated JET fast...

Investigation of Public Charging Infrastructure : Case study Gränby sportfält

OpenAIRE

Dahl, Emma; Hedström, Andreas; Lindgren, Anna

2017-01-01

The municipal company Sportfastigheter AB is currently renovating and developing Gränby sportfält, a sports field in Uppsala. Adjacent to the sports field, a parking lot for 700 vehicles is located, where Sportfastigheter AB is preparing to install charging points for electric vehicles (EVs) at some of the places. This bachelor thesis aims to investigate how a public charging solution should be modeled, with the parking lot at Gränby sportfält as a case study. The investigation involves estim...

Measurements of fast ion spatial dynamics during magnetic activity in the RFP

Science.gov (United States)

Goetz, J. A.; Anderson, J. K.; Bonofiglo, P.; Kim, J.; McConnell, R.; Magee, R. M.

2017-10-01

Fast ions in the RFP are only weakly affected by a stochastic magnetic field and behave nearly classically in concentration too low to excite Alfvenic activity. At high fast ion concentration sourced by H-NBI in 300kA RFP discharges, a substantial drop in core-localized high pitch fast ions is observed during bursts of coupled EPM and IAE (magnetic island-induced Alfven eigenmode) activity (100-200kHz) through neutral particle analysis. Sourcing instead fast deuterium with NBI, the DD fusion products can measure the dynamics of the fast ion density profile. Both a collimated neutron detector and a new 3MeV fusion proton detector loaned by TriAlpha Energy measure the fast ion density profile with 5cm spatial resolution and 100 μs temporal resolution. In D-NBI, the bursting EPM is excited at slightly lower frequency and the IAE activity is nearly absent, likely due to an isotope effect and loss of wave-particle interaction. In these cases, neutral particle analysis shows little change in the core-localized high pitch fast ion content, and the fusion product profile indicates little change in the fast ion density profile, leaving unexplained the mechanism removing EPM drive. We measure a substantial redistribution of the fast ion profile due to strong lower-frequency ( 30kHz) MHD activity that accompanies the current profile relaxation in the RFP. Profile flattening is strongest in low bulk density discharges, which often occur with a total increase in global neutron flux from acceleration of the beam ions. Work supported by US DoE.

Empirical Scaling Laws of Neutral Beam Injection Power in HL-2A Tokamak

International Nuclear Information System (INIS)

Cao Jian-Yong; Wei Hui-Ling; Liu He; Yang Xian-Fu; Zou Gui-Qing; Yu Li-Ming; Li Qing; Luo Cui-Wen; Pan Yu-Dong; Jiang Shao-Feng; Lei Guang-Jiu; Li Bo; Rao Jun; Duan Xu-Ru

2015-01-01

We present an experimental method to obtain neutral beam injection (NBI) power scaling laws with operating parameters of the NBI system on HL-2A, including the beam divergence angle, the beam power transmission efficiency, the neutralization efficiency and so on. With the empirical scaling laws, the estimating power can be obtained in every shot of experiment on time, therefore the important parameters such as the energy confinement time can be obtained precisely. The simulation results by the tokamak simulation code (TSC) show that the evolution of the plasma parameters is in good agreement with the experimental results by using the NBI power from the empirical scaling law. (paper)

The development of long pulse high voltage power supply for MNI-1U neutral beam injector

International Nuclear Information System (INIS)

Detai Wang

1989-01-01

A high power long pulse high voltage power supply (HVPS) for MNI- 1 U neutral beam injector (NBI) is described. This HVPS is used as a switching regulator with a duty cycle of 1/100, the specifications of circuit are as follows, output pulse voltage 50kv, pulse current 30A, pulse width 50ms, rise-time and fall-time of the voltage are less than 25 μs, stability of the pulse flat is better than 0.5%, regulation response time of the pulse voltage less than 30 μs can be attained. It is also used as a stable DC HVPS, output voltage is 1 to 100kv, current is 1 to 5A. If regulation tube is shunted with high power resistor in parallel, the current can be extended to 10 A, stability of the output voltage or current is better than 0.1%. Now, the HVPS has been put into operation for MNI- 1 U NBI and PIG ion source made in French. 3 refs., 5 figs

Zeff measurements and low-Z impurity transport for NBI and ICRF heated plasma in JIPP T-IIU tokamak

International Nuclear Information System (INIS)

Ida, K.; Amano, T.; Kawahata, K.; Kaneko, O.

1988-12-01

A visible bremsstrahlung detector array system for Z eff measurements and a charge exchange recombination spectroscopy (CXRS) system for fully ionized impurity profile measurements were installed on JIPP TII-U to study impurity transport for NBI and ICRF heated plasma. More impurities are sputtered by ICRF heating than by NBI and/or ohmic heatings. The carbon contribution to Z eff is 80-90 % for NBI heated plasmas, and 60 % for NBI + ICRF heated plasmas. With a carbon coating of vacuum vessel, the Z eff value decreases 2.4 to 1.7 and the carbon contribution to Z eff increases up to 80-90 %. We obtain the diffusion coefficient D a = 1.0 m 2 /s and the convective velocity V a (a) = 13 m/s at the plasma edge for carbon impurity from the radial profile and time evolution of fully ionized carbon after the ICRF pulse is turned on. (author)

Power and particle balance during neutral beam injection in TFTR

International Nuclear Information System (INIS)

Pitcher, C.S.; Budny, R.V.; Hill, K.W.; Kilpatrick, S.J.; Manos, D.M.; Medley, S.S.; Ramsey, A.T.

1991-05-01

Detailed boundary plasma measurements on TFTR have been made during a NBI power scan in the range P tot = 1MW--20MW in the L-mode regime. The behavior of the plasma density left-angle n e right-angle, radiated power P rad , carbon and deuterium fluxes Γ C , Γ D , and Ζ eff can be summarized as, left-angle n e right-angle ∝ P tot 1/2 , P rad , Γ C , Γ D ∝ P tot , and Ζ eff ∼ constant. It is shown that central fuelling by the neutral beams plays a minor role in the particle balance of the discharge. More important is the NBI role in the power balance. The TFTR data during NBI originate primarily at the graphite limiter

Review of particle-in-cell modeling for the extraction region of large negative hydrogen ion sources for fusion

Science.gov (United States)

Wünderlich, D.; Mochalskyy, S.; Montellano, I. M.; Revel, A.

2018-05-01

Particle-in-cell (PIC) codes are used since the early 1960s for calculating self-consistently the motion of charged particles in plasmas, taking into account external electric and magnetic fields as well as the fields created by the particles itself. Due to the used very small time steps (in the order of the inverse plasma frequency) and mesh size, the computational requirements can be very high and they drastically increase with increasing plasma density and size of the calculation domain. Thus, usually small computational domains and/or reduced dimensionality are used. In the last years, the available central processing unit (CPU) power strongly increased. Together with a massive parallelization of the codes, it is now possible to describe in 3D the extraction of charged particles from a plasma, using calculation domains with an edge length of several centimeters, consisting of one extraction aperture, the plasma in direct vicinity of the aperture, and a part of the extraction system. Large negative hydrogen or deuterium ion sources are essential parts of the neutral beam injection (NBI) system in future fusion devices like the international fusion experiment ITER and the demonstration reactor (DEMO). For ITER NBI RF driven sources with a source area of 0.9 × 1.9 m2 and 1280 extraction apertures will be used. The extraction of negative ions is accompanied by the co-extraction of electrons which are deflected onto an electron dump. Typically, the maximum negative extracted ion current is limited by the amount and the temporal instability of the co-extracted electrons, especially for operation in deuterium. Different PIC codes are available for the extraction region of large driven negative ion sources for fusion. Additionally, some effort is ongoing in developing codes that describe in a simplified manner (coarser mesh or reduced dimensionality) the plasma of the whole ion source. The presentation first gives a brief overview of the current status of the ion

Progress of the ''batman'' RF source for negative hydrogen ions

International Nuclear Information System (INIS)

Frank, P.; Heinemann, B.; Kraus, W.; Probst, F.; Speth, E.; Vollmer, O.; Bucalossi, J.; Trainham, R.

1998-01-01

The aim of a collaboration between CEA Cadarache and IPP Garching is to investigate the ability of an rf source to produce negative-ion current densities compatible with ITER NBI requirements (20 mA/cm 2 D-). A standard PlNI-size rf source developed for ASDEX-Upgrade and a three-grid extraction system form the basis of BATMAN (Bavarian Test Machine for Negative Ions). In the case of a pure hydrogen plasma a current density of 5.5 mA/cm 2 at elevated pressure (2.4 Pa) can be reached. Adding small amounts of argon ( 2 . In the low pressure range (0.7 Pa) the negative ion yield is strongly reduced, but with an admixture of argon and a cesium injection the current density is higher approx. by a factor 8 (4 mA/cm 2 ) compared to the pure hydrogen discharge. The negative ion yield shows a saturation with increasing rf power. (author)

Development of a high-current ion source with slit beam extraction for neutral beam injector of VEST

Energy Technology Data Exchange (ETDEWEB)

Jung, Bong-ki; Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr; An, Young-Hwa; Park, Jong-Yoon; Hwang, Y.S.

2015-10-15

Highlights: • A high-current ion source is developed for NBI system of VEST. • A cold-cathode electron gun is employed to produce primary electrons. • A hemi-cylindrical discharge chamber with cusp magnetic field is used. • Plasma density is measured to be 2 × 10{sup 18} m{sup −3} near the extraction aperture. • NBI power of 90 kW with beam energy of 20 keV is expected to be achieved. - Abstract: A high-current pulsed ion source has been developed for the neutral beam injector of the VEST (Versatile Experiment Spherical Torus) to accommodate high-beta fusion plasma experiments. The ion source consists of two parts: an electron gun for supplying sufficient primary electrons by cold-cathode arc discharge and a hemi-cylindrical discharge chamber where uniform, high-density plasma generated by the primary electrons is confined by multi-cusp magnetic field. A pulse forming network is also developed to drive high current of ∼1 kA to sustain the cold-cathode discharge in the electron gun up to 10 ms. Diagnostics with a triple probe in the discharge chamber shows that a hydrogen plasma whose density is as high as 1 × 10{sup 18} m{sup −3} can be obtained near extraction slits at the gas pressure lower than 0.5 Pa. This value is estimated to be sufficient to deposit a heating power of 90 kW to the VEST plasma when the appropriate extraction through slits with 20 cm{sup 2} in area and acceleration of ion beams up to 20 kV are fulfilled.

Status of the IPP RF Negative Ion Source Development for the ITER NBI System

International Nuclear Information System (INIS)

Peter Franzen, P.; Falter, H.-D.; Fantz, U.

2006-01-01

For heating and current drive the ITER neutral beam system requires negative hydrogen ion sources capable of delivering above 40 A of D - ions from a 1.5 x 0.6 m 2 source for up to one hour pulses with an accelerated current density of 200 A/m 2 . In order to reduce the losses by electron stripping in the acceleration system and the power loading of the grids, the source pressure is required to be 0.3 Pa at an electron/ion ratio 2 H - / 230 A/m 2 D - ) in excess of the ITER requirements have been already achieved on the small test facility '' BATMAN '' (Bavarian Test Machine for Negative Ions) at the required source pressure (0.3 Pa) and electron/ion ratio ( 2 ) and limited pulse length ( 2 and the pulse length up to 3600 s, using the same source as it is used at BATMAN. In order to demonstrate the required homogeneity of a large RF plasma source as well as the operation of an ITER relevant RF circuit, a so called '' half-size source '' - with roughly the width and half the height of the ITER source - was designed and went into operation on a dedicated plasma source test bed ('' RADI ''). An extensive diagnostic and modelling programme is accompanying those activities. The paper will present as an overview a summary of the latest results of the RF source development, with an emphasis on the first results of the operation of the half size ITER source and on the status of the long pulse operation. The details will be presented in several other papers. (author)

On fast-ion transport and burn control in Tokamaks

International Nuclear Information System (INIS)

Wising, F.

1994-01-01

Fast ions, generated by e.g. neutral beam injection (NBI), radio frequency (RF) heating or nuclear reactions, play an important role in all large tokamaks. Several issues related to fast ions and burning fusion plasmas are addressed in this thesis. Firstly, a new model of sawtooth oscillations is developed which explains the recent observations that q 0 remains below unity during the entire sawtooth cycle. The model features full reconnection in two current layers and provides a self-consistent description of the plasma states before and after the sawtooth crash. It is applied to the redistribution of fast NBI-ions in JET and comparisons are made with global as well as line-of-sight integrated D-D neutron measurements. Both the new model and the classical Kadomtsev model are found to be in agreement with the measurements. A simplified redistribution model is developed and applied to the redistribution of tritons and thermal ions, again giving reasonable agreement with D-T/D-D neutron measurements. Using a separate method, earlier results on expulsion of NBI-ions are confirmed. Secondly, a numerical study has been carried out of the coupled nonlinear evolution of alpha-particle driven kinetic Alfven wave turbulence and associated alpha transport. The saturated fluctuation spectrum consists of two peaks and results from nonlinear ion Compton scattering-induced transfer of energy from longer to shorter wavelengths. An analytical solution of the saturated spectrum, and estimates of the anomalous alpha diffusion coefficient, are given. The final paper addresses the problem of determining whether an initial temperature profile, established by e.g. auxiliary heating, will evolve to thermonuclear burn or quench under the influence of alpha particle heating and thermal conduction. Explicit burn criteria are presented and the beneficial effects of density and temperature peaking are discussed. 110 refs

Bootstrap current of fast ions in neutral beam injection heating

International Nuclear Information System (INIS)

Huang Qianhong; Gong Xueyu; Li Xinxia; Yu Jun

2012-01-01

The bootstrap current of fast ions produced by neutral beam injection (NBI) is investigated in a large-aspect-ratio tokamak with circular cross-section under specific parameters. The bootstrap current density distribution and the total bootstrap current are reported. In addition, the beam bootstrap current always accompanies the electron return current due to the parallel momentum transfer from fast ions. With the electron return current taken into consideration, the net current density obviously decreases; at the same time, the peak of the current moves towards the central plasma. Numerical results show that the value of the net current depends sensitively not only on the angle of the NBI but also on the ratio of the velocity of fast ions to the critical velocity: the value of the net current is small for neutral beam parallel injection, but increases severalfold for perpendicular injection, and increases with increasing beam energy. (paper)

Numerical Study of Instabilities Driven by Energetic Neutral Beam Ions in NSTX

International Nuclear Information System (INIS)

Belova, E.V.; Gorelenkov, N.N.; Cheng, C.Z.; Fredrickson, E.D.

2003-01-01

Recent experimental observations from NSTX [National Spherical Torus Experiment] suggest that many modes in a subcyclotron frequency range are excited during neutral-beam injection (NBI). These modes have been identified as Compressional Alfven Eigenmodes (CAEs) and Global Alfven Eigenmodes (GAEs), which are driven unstable through the Doppler-shifted cyclotron resonance with the beam ions. The injection velocities of the NBI ions in NSTX are large compared to Alfven velocity, V(sub)0 > 3V(sub)A, and a strong anisotropy in the fast-ion pitch-angle distribution provides the energy source for the instabilities. Recent interest in the excitation of Alfven Eigenmodes in the frequency range omega less than or approximately equal to omega(sub)ci, where omega(sub)ci is the ion cyclotron frequency, is related to the possibility that these modes can provide a mechanism for direct energy transfer from super-Alfvenic beam ions to thermal ions. Numerical simulations are required in order to find a self-consistent mode structure, and to include the effects of finite-Larmor radius (FLR), the nonlinear effects, and the thermal plasma kinetic effects

Narrow-band imaging (NBI for improving the assessment of vocal fold leukoplakia and overcoming the umbrella effect.

Directory of Open Access Journals (Sweden)

H Klimza

Full Text Available It is crucial to find a balance between functional and oncological outcome when choosing an adequate method for the management of vocal fold leukoplakia. Therefore, a detailed examination is a milestone in the decision-making process.To examine whether narrow-band imaging (NBI can be helpful in vocal fold assessment in the case of leukoplakia and how to overcome the "umbrella effect"- understood as the submucosal vascular pattern hidden under the plaque.Prospective cohort of 41 consecutive patients. Inclusion criteria: vocal fold leukoplakia, no previous procedures (surgery, radiotherapy, and preoperative endoscopy with an optical filter for NBI. Two groups: "suspicious" and "normal", according to the submucosal microvascular pattern of peripheral regions of the mucosa surrounding the plaque, were distinguished. Patients were qualified for a full-thickness or partial-thickness biopsy, respectively. Criteria defining suspected characters were well-demarcated brownish areas with scattered brown spots corresponding to type IV, Va, Vb, and Vc NI classifications.In 22/41 (53.7% patients with "suspected" microvascular pattern, full-thickness biopsy was performed. Moderate and severe dysplasia was revealed in 15 type IV and 7 type Va NI patients. In 19/41 (46.3% patients with proper NBI vessel pattern treated by partial-thickness biopsy, hyperkeratosis was diagnosed. There was a strong correlation between the NBI pattern and final histology: Chi2 (2 = 41.0 (p = 0.0000.The results demonstrate that NBI endoscopic assessment of the submucosal microvascular pattern of mucosa surrounding the plaque can be an effective method to categorise the risk in vocal fold leukoplakia prior to treatment.

Measurements of the fast ion distribution during neutral beam injection and ion cyclotron heating in ATF [Advanced Toroidal Facility

International Nuclear Information System (INIS)

Wade, M.R.; Kwon, M.; Thomas, C.E.; Colchin, R.J.; England, A.C.; Gossett, J.M.; Horton, L.D.; Isler, R.C.; Lyon, J.F.; Rasmussen, D.A.; Rayburn, T.M.; Shepard, T.D.; Bell, G.L.; Fowler, R.H.; Morris, R.N.

1990-01-01

A neutral particle analyzer (NPA) with horizontal and vertical scanning capability has been used to make initial measurements of the fast ion distribution during neutral beam injection (NBI) and ion cyclotron heating (ICH) on the Advanced Toroidal Facility (ATF). These measurements are presented and compared with the results of modeling codes that predict the analyzer signals during these heating processes. 6 refs., 5 figs

A scoping study of the application of neutral beam heating on the TCV tokamak

Energy Technology Data Exchange (ETDEWEB)

Karpushov, Alexander N., E-mail: alexander.karpushov@epfl.ch [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH-1015 Lausanne (Switzerland); Duval, Basil P.; Chavan, Rene [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH-1015 Lausanne (Switzerland); Fable, Emiliano [Max-Planck-Institut fuer Plasmaphysik, Euratom-IPP Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Mayor, Jean-Michel; Sauter, Olivier; Weisen, Henri [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH-1015 Lausanne (Switzerland)

2011-10-15

The TCV tokamak contributes to the physics understanding of fusion plasmas, broadening the parameter range of reactor relevant regimes, by investigations based on an extensive use of the existing main experimental tools: flexible shaping and high power real time-controllable electron cyclotron heating (ECH) and current drive (ECCD) systems. A proposed implementation of direct ion heating on the TCV by the installation of a 20-35 keV neutral beam injection (NBI) with a total power of 1-3 MW would permit an extension of the accessible range of ion to electron temperatures (T{sub i}/T{sub e} {approx} 0.1-0.8) to well beyond unity, depending on the NBI/ECH mix and the plasma density. A NBI system would provide TCV with a tool for plasma study at reactor relevant T{sub i}/T{sub e} ratios {approx}1 and in investigating fast ion and MHD physics together with the effects of plasma rotation and high plasma {beta} scenarios. The feasibility studies for a NBI heating on TCV presented in this paper were undertaken to construct a specification for the neutral beam injectors together with an experimental geometry for possible operational scenarios.

Integrated heat transport simulation of high ion temperature plasma of LHD

International Nuclear Information System (INIS)

Murakami, S.; Yamaguchi, H.; Sakai, A.

2014-10-01

A first dynamical simulation of high ion temperature plasma with carbon pellet injection of LHD is performed by the integrated simulation GNET-TD + TASK3D. NBI heating deposition of time evolving plasma is evaluated by the 5D drift kinetic equation solver, GNET-TD and the heat transport of multi-ion species plasma (e, H, He, C) is studied by the integrated transport simulation code, TASK3D. Achievement of high ion temperature plasma is attributed to the 1) increase of heating power per ion due to the temporal increase of effective charge, 2) reduction of effective neoclassical transport with impurities, 3) reduction of turbulence transport. The reduction of turbulence transport is most significant contribution to achieve the high ion temperature and the reduction of the turbulent transport from the L-mode plasma (normal hydrogen plasma) is evaluated to be a factor about five by using integrated heat transport simulation code. Applying the Z effective dependent turbulent reduction model we obtain a similar time behavior of ion temperature after the C pellet injection with the experimental results. (author)

Stopping power for heavy ions in low energy region

International Nuclear Information System (INIS)

Kitagawa, Mitsuo

1983-01-01

Review is made for the study on the power for stopping heavy ions. The studies on the power for stopping heavy ions passing through materials have been developed in the last twenty years due to the accuracy improvement in the data analysis of the power for stopping light ions, the requirement of data establishment on the power for stopping heavy ions from fusion research and the development of the experimental studies by heavy-ion accelerators. The relation between the analysis of the power for stopping heavy ions and the power for stopping light ions is described from the standpoint that the results on the power for stopping light ions serve as the guide for the study on the power for stopping heavy ions. Both at present and in future. The analysis of stopping power data with the accuracy from +-10 to 20 % is possible from the theoretical analysis of effective electric charge and its systematic table of the numerical data. The outline of the scaling rule on effective electric charge is discussed. The deviation of the experimental data from the scaling rule is discussed by comparing with the measured values of effective electric charge ratio. Various analyses of the power for stopping heavy ions are summarized. (Asami, T.)

Beam calorimetry at the large negative ion source test facility ELISE: Experimental setup and latest results

International Nuclear Information System (INIS)

Nocentini, Riccardo; Bonomo, Federica; Ricci, Marina; Pimazzoni, Antonio; Fantz, Ursel; Heinemann, Bernd; Riedl, Rudolf; Wünderlich, Dirk

2016-01-01

Highlights: • ELISE is the first step in the European roadmap for the development of the ITER NBI. • Several beam diagnostic tools have been installed, the latest results are presented. • A gaussian fit procedure has been implemented to characterize the large ion beam. • Average beamlet group inhomogeneity is maximum 13%, close to the ITER target of 10%. • Beam divergence measured by calorimeter agrees with the BES measurements within 30%. - Abstract: The test facility ELISE is the first step within the European roadmap for the development of the ITER NBI system. ELISE is equipped with a 1 × 0.9 m"2 radio frequency negative ion source (half the ITER source size) and an ITER-like 3-grid extraction system which can extract an H"− or D"− beam for 10 s every 3 min (limited by available power supplies) with a total acceleration voltage of up to 60 kV. In the beam line of ELISE several beam diagnostic tools have been installed with the aim to evaluate beam intensity, divergence and uniformity. A copper diagnostic calorimeter gives the possibility to measure the beam power density profile with high resolution. The measurements are performed by an IR micro-bolometer camera and 48 thermocouples embedded in the calorimeter. A gaussian fit procedure has been implemented in order to characterize the large negative ion beam produced by ELISE. The latest results obtained from the beam calorimetry at ELISE show that the average beamlet group inhomogeneity is maximum 13%. The measured beam divergence agrees with the one measured by beam emission spectroscopy within 30%.

Simulations of beam-fueled supershot-like plasmas near ignition

International Nuclear Information System (INIS)

Budny, R.V.; Grisham, L.; Jassby, D.L.

1992-01-01

In certain conditions, neutral beam injection (NBI) and low recycling result in supershot plasmas. These are characterized by peaked density profiles and high central ion temperatures. We discuss the potential advantages of NBI fueled supershot-like plasmas in tokamaks operating near ignition. The goal is to investigate the feasibility of these plasmas to aid in the design of future advanced tokamaks. NBI has been very successful in advancing tokamak plasmas close to ignition conditions. The primary benefits of NBI are heating and particle fueling, but the plasma currents generated by the beam ions are also of considerable interest. The optimal injection energy E inj for the beam ions depends on the desired role of the NBI. For central particle fueling, E inj should be low to maximize the particle current at fixed P B , but high enough to penetrate to the center. For heating and current drive, higher E inj is preferable for deepest penetration. With the standard positive ion beam technology, the neutralization efficiency becomes too low for useful power densities if E inj is significantly greater than about 120 keV. Negative ion beam sources would be useful for heating and current drive at very high E inj (500 keV or more), but the fueling rate of NBI is too low to be practical. It seems generally accepted that future tokamaks which operate closer to ignition will have to be fueled and heated by means other than NBI since it is argued that the beams with low E inj cannot penetrate deeply into the dense plasmas of interest. (author) 3 refs., 4 figs

Fast-ion transport studies using FIDA spectroscopy at the ASDEX Upgrade tokamak

International Nuclear Information System (INIS)

Geiger, Benedikt

2013-01-01

A good confinement of fast-ions, i.e. ions with energies above the thermal energy, is essential for the success of fusion devices as it determines, amongst others, the plasma performance and the heating and current drive efficiencies. In case of a turbulent or magneto-hydrodynamic (MHD) active background plasma, various mechanisms have to be considered in order to estimate the spatial distribution of the fast-ions: the slowing down and radial diffusion by Coulomb collisions on electrons and ions, the effect of potential fluctuations and the effect of perturbations of the magnetic field structure. These can lead to a broadening of the fast-ion distribution function which is not yet completely understood. At the fusion experiment ASDEX Upgrade, the fast-ions are generated by heating sources such as neutral beam injection (NBI). Their transport properties can be studied by a fast-ion D-alpha (FIDA) spectroscopy diagnostic which has been built in the framework of this thesis. Through charge exchange reactions with neutrals, fast-ions can receive a bound electron and emit Balmer alpha line radiation. This so-called FIDA radiation can be measured with large Doppler shifts and is localized along the NBI path where a high density of neutrals is present. The FIDA diagnostic uses radially distributed lines of sight that intersect, in the horizontal and in the vertical plane, the path of a 2.5 MW NBI heating source. Thereby different parts of the fast-ion phase space above 25 keV can be analyzed. To interpret the FIDA radiation quantitatively, a forward modelling code has been implemented, tested and further developed. The code calculates, based on theoretical fast-ion distribution functions, synthetic FIDA spectra that can be compared to the measurement. In MHD-quiescent plasmas, the possible effect of turbulence on the fast-ion transport has been investigated with the FIDA diagnostic. The measurements obtained under different experimental conditions, such as during on- and

Fusion reactor development using high power particle beams

International Nuclear Information System (INIS)

Ohara, Y.

1990-01-01

The present paper outlines major applications of the ion source/accelerator to fusion research and also addresses the present status and future plans for accelerator development. Applications of ion sources/accelerators for fusion research are discussed first, focusing on plasma heating, plasma current drive, plasma current profile control, and plasma diagnostics. The present status and future plan of ion sources/accelerators development are then described focusing on the features of existing and future tokamak equipment. Positive-ion-based NBI systems of 100 keV class have contributed to obtaining high temperature plasmas whose parameters are close to the fusion break-even condition. For the next tokamak fusion devices, a MeV class high power neutral beam injector, which will be used to obtain a steady state burning plasma, is considered to become the primary heating and current drive system. Development of such a system is a key to realize nuclear fusion reactor. It will be entirely indebted to the development of a MeV class high current negative deuterium ion source/accelerator. (N.K.)

Plasma heating and hot ion sustaining in mirror based hybrids

International Nuclear Information System (INIS)

Moiseenko, V. E.; Ågren, O.

2012-01-01

Possibilities of plasma heating and sloshing ion sustaining in mirror based hybrids are briefly reviewed. Sloshing ions, i.e. energetic ions with a velocity distribution concentrated to a certain pitch-angle, play an important role in plasma confinement and generation of fusion neutrons in mirror machines. Neutral beam injection (NBI) is first discussed as a method to generate sloshing ions. Numerical results of NBI modeling for a stellarator-mirror hybrid are analyzed. The sloshing ions could alternatively be sustained by RF heating. Fast wave heating schemes, i.e. magnetic beach, minority and second harmonic heating, are addressed and their similarities and differences are described. Characteristic features of wave propagation in mirror hybrid devices including both fundamental harmonic minority and second harmonic heating are examined. Minority heating is efficient for a wide range of minority concentration and plasma densities; it allows one to place the antenna aside from the hot ion location. A simple-design strap antenna suitable for this has good performance. However, this scenario is appropriate only for light minority ions. The second harmonic heating can be applied for the heavy ion component. Arrangements are similar for minority and second harmonic heating. The efficiency of second harmonic heating is influenced by a weaker wave damping than for minority heating. Numerical calculations show that in a hybrid reactor scaled mirror machine the deuterium sloshing ions could be heated within the minority heating scheme, while the tritium ions could be sustained by second harmonic heating.

Fast ion behavior during neutral beam injection in ATF

International Nuclear Information System (INIS)

Wade, M.R.; Thomas, C.E.; Colchin, R.J.; Rome, J.A.; England, A.C.; Fowler, R.H.; Aceto, S.C.

1993-01-01

In stellarators, single-particle confinement properties can be more complex than in their tokamak counterparts. Fast-ion behavior in tokamaks has been well characterized through an abundance of measurements on various devices and in general has been shown to be consistent with classical slowing-down theory, although anomalous ion behavior has been observed during intense beam injection in ISX-B, during fishbone instabilities in PDX, and in experiments on TFR. In contrast, fast ion behavior in stellarators is not as wel established experimentally with the primary experiments to date focusing o near-perpendicular or perpendicular neutral beam injection (NBI) on the Wendelstein 7-A stellarator (91 and Heliotron-E. This paper addresses fast-ion confinement properties in a large-aspect-ratio, moderate-shear stellarator, the Advanced Toroidal Facility, during tangential NBI. The primary data used in this study are the experimentally measured energy spectra of charge-exchange neutrals escaping from the plasma, using a two-dimensional scanning neutral particle analyzer. This diagnostic method is well established, having been used on several devices since the early 1970's. Various aspects of fast-ion behavior are investigated by comparing these data with computed theoretical spectra based on energeticion distributions derived from the fastion Fokker-Planck equation. Ion orbits are studied by computer orbit following, by the computation of J* surfaces, and by Monte Carlo calculations

Simulations of enhanced ion stopping power experiments

International Nuclear Information System (INIS)

Mehlhorn, T.A.; Maenchen, J.E.; Olsen, J.N.; Johnson, D.J.

1984-01-01

As the material in an ICF target is heated and ionized by an intense ion beam, the ion stopping power changes from that of neutral atoms. This changes the energy deposition characteristics of the ion beam and thereby can profoundly influence the target dynamics. An accurate ion energy deposition model is important for designing ICF targets that perform in an optimal fashion. An experiment to measure a time-resolved ion stopping power history in a partially ionized target is being fielded on the PROTO I accelerator at Sandia Labs. This experiment utilizes a voltage ramped Thomson parabola to provide a time-history of the ion energy incident upon and exiting from a cylindrical target foil

Magnetohydrodynamic behaviour during core transport barrier experiments with ion Bernstein wave heating in PBX-M: I ELMs fluctuations and crash events

International Nuclear Information System (INIS)

Sesnic, S.; Kaita, R.; Batha, S.H.

1998-01-01

If the ion Bernstein wave (IBW) heating power in an H mode discharge of the PBX-M experiment exceeds a threshold power of about 200 kW, a core transport barrier is created in the central region of the plasma. At lower neutral beam injection (NBI) powers, the core barrier is accompanied by an edge L mode. The high edge localized mode (ELM) repetition frequency (1 kHz) prevents the creation of a strong barrier, so the edge first has to make an H-to-L transition before a strong core transport barrier can be created. At higher NBI powers, the ELM repetition frequency is lowered to less than 200 Hz, which allows the immediate creation of a strong core barrier. Edge localized mode loss, which propagates radially first on a fast (non-diffusive) and then on a slow (diffusive) time-scale all the way to the plasma core, is strongly reduced in the core barrier region. Correlated with the reduced ELM loss, the fluctuations in the core barrier region are also strongly reduced, both during the ELM and during the quite periods between the ELMs. There is strong evidence that the IBW induced poloidal flow shear is responsible for the stabilization of core turbulence and the creation of the core transport barrier. The large perpendicular E x B flow shear component of the measured toroidal velocity in co-injection neutral beam heated discharges seems to be largely cancelled by the ion diamagnetic drift shear produced by large ion pressure gradients in the core barrier region. The value of IBW induced poloidal flow has not been experimentally determined, but its numerical value is found to be a factor of 4 larger than either the toroidal velocity or the ion diamagnetic drift shear components, leaving only IBW induced flow shear as the most probable cause for the turbulence stabilization. The core turbulence suppression and the creation of the core transport barrier is also consistent with expectations from a comparison between the E x B flow shear rate and a rough estimate of the

Comparison of collective Thomson scattering signals due to fast ions in ITER scenarios with fusion and auxiliary heating

DEFF Research Database (Denmark)

Salewski, Mirko; Asunta, O.; Eriksson, L.-G.

2009-01-01

Auxiliary heating such as neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH) will accelerate ions in ITER up to energies in the MeV range, i.e. energies which are also typical for alpha particles. Fast ions of any of these populations will elevate the collective Thomson...... functions of fast ions generated by NBI and ICRH are calculated for a steady-state ITER burning plasma equilibrium with the ASCOT and PION codes, respectively. The parameters for the auxiliary heating systems correspond to the design currently foreseen for ITER. The geometry of the CTS system for ITER...... is chosen such that near perpendicular and near parallel velocity components are resolved. In the investigated ICRH scenario, waves at 50MHz resonate with tritium at the second harmonic off-axis on the low field side. Effects of a minority heating scheme with He-3 are also considered. CTS scattering...

Thermal analyses for the design of the ITER-NBI arc driven ion source

International Nuclear Information System (INIS)

Anaclerio, G.; Peruzzo, S.; Dal Bello, S.; Palma, M.D.; Nocentini, R.; Zaccaria, P.

2006-01-01

The design of the first ITER NB Injector and the ITER NB Test Facility is presently in progress in the framework of EFDA contracts with the contribution of several European Associations. One of the components currently studied by Consorzio RFX Team is the arc driven negative ion source, which is designed to produce a D - beam of 40 A at 1 MeV for 3600 s pulses, generated in the ion source via a surface production process in a caesium-seeded arc discharge of 790 kW total power. This paper will focus in particular on the thermal analyses carried out in order to evaluate the thermal behaviour in nominal operating conditions of the main components of the ion source: the arc-chamber and the filament cassette assembly. The study is based on hydraulic, thermo-mechanical and thermo-electrical calculations performed by means of 2D and 3D finite element models, with inputs coming partly from the ITER reference design documentation and partly from the design review activities presently in progress. Moreover a complete modelling of all the components of the beam source assembly by means of new 3D CAD models was carried out to demonstrate the feasibility of the proposed design. For the arc chamber, an assessment of the cooling circuit has been performed and hydraulic analyses have been carried out to calculate water flow rates and pressures inside the cooling channels. Thermo-mechanical analyses have been carried out considering several load cases and different water flow rates. The maximum and average temperatures of the arc chamber walls have been calculated to verify the operational conditions and the fulfilment of physics requirements for the negative ion generation. For the filament cassette assembly, an assessment of the effectiveness of the cooling system has been carried out considering two different design solutions: the first based on the reference design, with a dedicated active cooling system integrated in the filament cassette; the other based on a simplified

Pulsed power ion accelerators for inertially confined fusion

International Nuclear Information System (INIS)

Olson, C.L.

1976-01-01

Current research is described on pulsed power ion accelerators for inertial fusion, i.e., ion diodes and collective accelerators. Particle beam energy and power requirements for fusion, and basic deposition characteristics of charged particle beams are discussed. Ion diodes and collective accelerators for fusion are compared with existing conventional accelerators

An analysis of plasma ion toroidal rotation during large amplitude MHD activity in JET

International Nuclear Information System (INIS)

Snipes, J.A.; Esch, H.P.L. de; Lazzaro, E.; Stork, D.; Hellermann, M. von; Galvao, R.; Hender, T.C.; Zasche, D.

1989-01-01

A detailed study of plasma ion toroidal rotation in JET during large amplitude MHD activity has revealed a strong viscous force that couples plasma ions to MHD modes. Depending on the MHD modes present, this force can couple across all of the plasma cross section, across only the central region, roughly within the q=1 surface, or across only the outer region outside the q=1.5 surface. The force acts to flatten the ion toroidal rotation frequency profile, measured by the JET active charge exchange spectroscopy diagnostic, across the coupled region of plasma. The frequency of rotation in this region agrees with the MHD oscillation frequency measured by magnetic pick-up coils at the wall. The strength of the force between the ions and modes becomes evident during high power NBI when the mode locks and drags the ion toroidal rotation frequency to zero, within the errors of the measurements. The present theories of plasma rotation either ignore MHD effects entirely, consider only moderate n toroidal field ripple, or low n ripple effects. (author) 7 refs., 3 figs

Ion exchange in the nuclear power industry

International Nuclear Information System (INIS)

Lehto, J.

1993-01-01

Ion exchangers are used in many fields in the nuclear power industry. At nuclear power plants, organic ion exchange resins are mainly used for the removal of ionic and particulate contaminants from the primary circuit, condensate and fuel storage pond waters. Ion exchange resins are used for the solidification of low- and medium-active nuclear waste solutions. The number of applications of zeolites, and other inorganic ion exchangers, in the separation of radionuclides from nuclear waste solutions has been increasing since the 1980s. In nuclear fuel reprocessing plants, ion exchange is used for the solidification of low- and medium-active waste solutions, as well as for the partitioning of radioactive elements for further use. (Author)

Transport in Auxiliary Heated NSTX Discharges

International Nuclear Information System (INIS)

LeBlanc, B.P.; Bell, M.G.; Bell, R.E.; Bitte, M.L.; Bourdelle, C.; Gates, D.A.; Kaye, S.M.; Maingi, R.; Menard, J.E.; Mueller, D.; Ono, M.; Paul, S.F.; Redi, M.H.; Roquemore, A.L.; Rosenberg, A.; Sabbagh, S.A.; Stutman, D.; Synakowski, E.J.; Soukhanovskii, V.A.; Wilson, J.R.

2003-01-01

The NSTX spherical torus (ST) provides a unique platform to investigate magnetic confinement in auxiliary-heated plasmas at low aspect ratio. Auxiliary power is routinely coupled to ohmically heated plasmas by deuterium neutral-beam injection (NBI) and by high-harmonic fast waves (HHFW) launch. While theory predicts both techniques to preferentially heat electrons, experiment reveals the electron temperature is greater than the ion temperature during HHFW, but the electron temperature is less than the ion temperature during NBI. In the following we present the experimental data and the results of transport analyses

Universal Linear Precoding for NBI-Proof Widely Linear Equalization in MC Systems

Directory of Open Access Journals (Sweden)

Donatella Darsena

2007-09-01

Full Text Available In multicarrier (MC systems, transmitter redundancy, which is introduced by means of finite-impulse response (FIR linear precoders, allows for perfect or zero-forcing (ZF equalization of FIR channels (in the absence of noise. Recently, it has been shown that the noncircular or improper nature of some symbol constellations offers an intrinsic source of redundancy, which can be exploited to design efficient FIR widely-linear (WL receiving structures for MC systems operating in the presence of narrowband interference (NBI. With regard to both cyclic-prefixed and zero-padded transmission techniques, it is shown in this paper that, with appropriately designed precoders, it is possible to synthesize in both cases WL-ZF universal equalizers, which guarantee perfect symbol recovery for any FIR channel. Furthermore, it is theoretically shown that the intrinsic redundancy of the improper symbol sequence also enables WL-ZF equalization, based on the minimum mean output-energy criterion, with improved NBI suppression capabilities. Finally, results of numerical simulations are presented, which assess the merits of the proposed precoding designs and validate the theoretical analysis carried out.

Analysis of active and passive magnetic field reduction systems (MFRS) of the ITER NBI

International Nuclear Information System (INIS)

Roccella, M.; Lucca, F.; Roccella, R.; Pizzuto, A.; Ramogida, G.; Portone, A.; Tanga, A.; Formisano, A.; Martone, R.

2007-01-01

In ITER two heating (HNBI) and one diagnostic neutral beam injectors (DNBI) are foreseen. Inside these components there are very stringent limits on the magnetic field (the flux density must be below some G along the ion path and below 20 G in the neutralizing regions). To achieve these performances in an environment with high stray field due to the plasma and the poloidal field coils (PFC), both passive and active shielding systems have been foreseen. The present design of the magnetic field reduction systems (MFRS) is made of seven active coils and of a box surrounding the NBI region, consisting of ferromagnetic plates. The electromagnetic analyses of the effectiveness of these shields have been performed by a 3D FEM model using ANSYS code for the HNBI. The ANSYS models of the ferromagnetic box and of the active coils are fully parametric, thus any size change of the ferromagnetic box and coils (linear dimension or thickness) preserving the overall box shape could be easily reproduced by simply changing some parameter in the model

Analysis of active and passive magnetic field reduction systems (MFRS) of the ITER NBI

Energy Technology Data Exchange (ETDEWEB)

Roccella, M. [L.T. Calcoli S.a.S., Piazza Prinetti 26/B, Merate (Lecco) (Italy)], E-mail: roccella@ltcalcoli.it; Lucca, F.; Roccella, R. [L.T. Calcoli S.a.S., Piazza Prinetti 26/B, Merate (Lecco) (Italy); Pizzuto, A.; Ramogida, G. [Associazione EURATOM sulla Fusione - ENEA Frascati (Italy); Portone, A.; Tanga, A. [ITER EFDA (Italy); Formisano, A.; Martone, R. [CREATE Napoli (Italy)

2007-10-15

In ITER two heating (HNBI) and one diagnostic neutral beam injectors (DNBI) are foreseen. Inside these components there are very stringent limits on the magnetic field (the flux density must be below some G along the ion path and below 20 G in the neutralizing regions). To achieve these performances in an environment with high stray field due to the plasma and the poloidal field coils (PFC), both passive and active shielding systems have been foreseen. The present design of the magnetic field reduction systems (MFRS) is made of seven active coils and of a box surrounding the NBI region, consisting of ferromagnetic plates. The electromagnetic analyses of the effectiveness of these shields have been performed by a 3D FEM model using ANSYS code for the HNBI. The ANSYS models of the ferromagnetic box and of the active coils are fully parametric, thus any size change of the ferromagnetic box and coils (linear dimension or thickness) preserving the overall box shape could be easily reproduced by simply changing some parameter in the model.

Clinical experiences of NBI laryngoscope in diagnosis of laryngeal lesions

Science.gov (United States)

Qi, Xinmeng; Yu, Dan; Zhao, Xue; Jin, Chunshun; Sun, Changling; Liu, Xueshibojie; Cheng, Jinzhang; Zhang, Dejun

2014-01-01

Endoscopy is essential for the diagnosis and treatment of cancers derived from the larynx. However, a laryngoscope with conventional white light (CWL) has technical limitations in detecting small or superficial lesions on the mucosa. Narrow band imaging especially combined with magnifying endoscopy (ME) is useful for the detection of superficial squamous cell carcinoma (SCC) within the oropharynx, hypopharynx, and oral cavity. A total of 3675 patients who have come to the outpatient clinic and complained of inspiratory stridor, dyspnea, phonation problems or foreign body sensation, were enrolled in this study. We describe the glottic conditions of the patients. All 3675 patients underwent laryngoscopy equipped with conventional white light (CWL) and NBI system. 1149 patients received a biopsy process. And 1153 lesions were classified into different groups according to their histopathological results. Among all the 1149 patients, 346 patients (312 males, 34 females; mean age 62.2±10.5 years) were suspected of having a total of 347 precancerous or cancerous (T1 or T2 without lymphnode involvement) lesions of the larynx under the CWL. Thus, we expected to attain a complete vision of what laryngeal lesions look like under the NBI view of a laryngoscope. The aim was to develop a complete description list of each laryngeal conditions (e.g. polyps, papilloma, leukoplakia, etc.), which can serve as a criteria for further laryngoscopic examinations and diagnosis. PMID:25419362

Study of high energy ion loss during hydrogen minority heating in TFTR

International Nuclear Information System (INIS)

Park, J.; Zweben, S.J.

1994-03-01

High energy ion loss during hydrogen minority ICRF heating is measured and compared with the loss of the D-D fusion products. During H minority heating a relatively large loss of high energy ions is observed at 45 degrees below the outer midplane, with or without simultaneous NBI heating. This increase is most likely due to a loss of the minority tail protons, a possible model for this process is described

Accounting of the Power Balance for Neutral-beam heated H-Mode Plasmas in NSTX

International Nuclear Information System (INIS)

Paul, S.F.; Maingi, R.; Soukhanovskii, V.; Kaye, S.M.; Kugel, H.

2004-01-01

A survey of the dependence of power balance on input power, shape, and plasma current was conducted for neutral-beam-heated plasmas in the National Spherical Torus Experiment (NSTX). Measurements of heat to the divertor strike plates and divertor and core radiation were taken over a wide range of plasma conditions. The different conditions were obtained by inducing a L-mode to H-mode transition, changing the divertor configuration [lower single null (LSN) vs. double-null (DND)] and conducting a NBI power scan in H-mode. 60-70% of the net input power is accounted for in the LSN discharges with 20% of power lost as fast ions, 30-45% incident on the divertor plates, up to 10% radiated in the core, and about 12% radiated in the divertor. In contrast, the power accountability in DND is 85-90%. A comparison of DND and LSN data show that the remaining power in the LSN is likely to be directed to the upper divertor

Measurement of stopping power of heavy ions

International Nuclear Information System (INIS)

Kitahara, Tetsuo

1981-01-01

The stopping power of heavy ions is discussed. In the low energy region, heavy ions keep some of their orbital electrons, and have equilibrium electron charge. The stopping power of penetrating particles depends on this effective charge. At present, it is hard to estimate this effective charge theoretically, accordingly, the estimation is made experimentally. Another difficulty in this estimation is that the Born approximation is not effective for heavy ions. In the low energy region, electronic stopping and nuclear stopping contribute to the stopping power. For the electronic stopping, a formula for the stopping power was given by Lindhard et al. The experimental values were obtained at GSI, and are inconsistent with the estimation by the Lindhard's formula. In the high energy region, where the Born approximation can be used, the Bethe's formula is applied, but the experimental data are scarce. Oscillations are seen in the Z dependence graph of the experimental stopping cross sections. Experimental works on the stopping power have been done. The differential and the integral methods were carried out. (Kato, T.)

High-definition velocity-space tomography of fast-ion dynamics

DEFF Research Database (Denmark)

Salewski, Mirko; Geiger, B.; Jacobsen, A.S.

2016-01-01

Velocity-space tomography of the fast-ion distribution function in a fusion plasma is usually a photon-starved tomography method due to limited optical access and signal-to-noise ratio of fast-ion Dα (FIDA) spectroscopy as well as the strive for high-resolution images. In high-definition tomography...... information to reconstruct where in velocity space the measurements and the simulation disagree. This alternative approach is demonstrated for four-view as well as for two-view FIDA measurements. The high-definition tomography tools allow us to study fast ions in sawtoothing plasmas and the formation of NBI...

Neoclassical transport of energetic beam ions in the Large Helical Device

International Nuclear Information System (INIS)

Murakami, Sadayoshi; Yamada, Hiroshi; Kaneko, Osamu

2000-01-01

The neoclassical (collisional) transport of energetic ions is investigated by the global neoclassical transport simulation in the Large Helical Device (LHD). The steady state distributions of energetic ions are evaluated assuming an energetic particle source by NBI heating (tangentally injected). Significant radial transport of energetic ions can be seen due to the radial motion of trapped particles in the velocity region below near critical velocity. Our simulation results show relatively good agreements with the experimental results of fast particle measurements in the LHD. This suggests an important role of neoclassical transport in the radial transport process of energetic ions in heliotrons. (author)

Negative ion sourcery

International Nuclear Information System (INIS)

Os, C.F.A. van.

1989-01-01

The work described in this thesis is involved by current research programs in the field of nuclear-fusion. A brief introduction to fusion is given, anticipated problems related to current drive of the fusion plasma are pinpointed and probable suggestions to overcome these problems are described. One probable means for current drive is highlighted; Neutral Beam Injection (NBI). This is based on injecting a 1 MeV neutral hydrogen or deuterium beam into a fusion plasma. Negative ions are needed as primary particles because they can easily be neutralized at 1 MeV. The two current schemes for production of negative ions are described, volume production and negative surface ionization. The latter method is extensively studied in this thesis. (author). 171 refs.; 55 figs.; 7 tabs

Demonstration tokamak fusion power plant for early realization of net electric power generation

International Nuclear Information System (INIS)

Hiwatari, R.; Okano, K.; Asaoka, Y.; Shinya, K.; Ogawa, Y.

2005-01-01

A demonstration tokamak fusion power plant Demo-CREST is proposed as the device for early realization of net electric power generation by fusion energy. The plasma configuration for Demo-CREST is optimized to satisfy the electric breakeven condition (the condition for net electric power, P e net = 0 MW) with the plasma performance of the ITER reference operation mode. This optimization method is considered to be suitable for the design of a demonstration power plant for early realization of net electric power generation, because the demonstration power plant has to ensure the net electric generation. Plasma performance should also be more reliably achieved than in past design studies. For the plasma performance planned in the present ITER programme, net electric power from 0 to 500 MW is possible with Demo-CREST under the following engineering conditions: maximum magnetic field 16 T, thermal efficiency 30%, NBI system efficiency 50% and NBI current drive power restricted to 200 MW. By replacing the blanket system with one of higher thermal efficiency, a net electric power of about 1000 MW is also possible so that the performance of the commercial plant with Demo-CREST can also be studied from the economic point of view. The development path from the experimental reactor 'ITER' to the commercial plant 'CREST' through the demonstration power plant 'Demo-CREST' is proposed as an example of the fast track concept. (author)

Highly radiative plasmas for local transport studies and power and particle handling in reactor regimes

International Nuclear Information System (INIS)

Hill, K.W.; Bell, M.G.; Budny, R.

1999-01-01

To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into TFTR supershots and high-l i plasmas. At neutral beam injection (NBI) powers P B ≥ 30 MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both D and DT plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in ITER. The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms. (author)

Highly radiative plasmas for local transport studies and power and particle handling in reactor regimes

International Nuclear Information System (INIS)

Hill, K.W.; Bell, M.G.; Budny, R.

2001-01-01

To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into TFTR supershots and high-l i plasmas. At neutral beam injection (NBI) powers P B ≤30MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both D and DT plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in ITER. The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms. (author)

Study on improvement of the lifetime of a field-reversed configuration by tangential neutron beam injection

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kondoh, Yoshiomi; Hirano, Yoichi; Asai, Tomohiko; Takahashi, Tsutomu; Mizuguchi, Naoki; Tomita, Yukihiro

2006-01-01

The numerical analysis of neutron beam injection (NBI) is carried out to keep the stationary conditions of the field-reversed configuration (FRC) plasma. The ionization process of neutron beam was reproduced by the Monte Carlo method. A confinement of 15 keV beam ion was investigated using the sharp of stormer region obtained by the position and velocity at a moment of ionization. The relation between the external magnetic field B ex [T] and radius of machine r w [m] was shown by B ex = 0.1 r w -3/4 . The power imparted to plasma was estimated by beam ion orbital calculation. The confinement coefficient of beam ion was lost by re-charge-exchange reaction with deuterium; this fact was discovered at first. In order to keep the configuration of plasma under the conditions of 0.2 T of the external magnetic field, 0.4 m of radius, and 100 eV ion temperature, about 17 MW/m NBI power is needed. (S.Y.)

Empirical stopping powers for ions in solids

International Nuclear Information System (INIS)

Ziegler, J.F.; Biersack, J.P.; Littmark, U.

1983-01-01

The work of Brandt and collaborators on low energy ion stopping powers has been extended to create an empirical formulation for the stopping of ions in solids. The result is a simple computer program (about 60 lines of code) which calculates stopping powers from zero to 100 MeV/amu for all ions in all elemental solids. This code has been compared to the data in about 2000 papers, and has a standard error of 9% for energies above keV/amu. This approach includes high energy relativistic effects and shell-corrections. In the medium energy range it uses stopping theory based on the local-density approximation and Lindhard stopping in a free electron gas. This is applied to realistic Hartree-Fock charge distributions for crystalline solids. In the low energy range it uses the Brandt concepts of ion stripping relative to the Fermi velocity of solids, and also his formalism for the relation of projectile ionization to its effective charge. The details of the calculation are presented, and a broad comparison is shown with experiment. Special comparative examples are shown of both the low energy stopping power oscillations which depend on the atomic number of the ion, and also of the target

A Neutral Beam Injector Upgrade for NSTX

International Nuclear Information System (INIS)

Stevenson, T.; McCormack, B.; Loesser, G.D.; Kalish, M.; Ramakrishnan, S.; Grisham, L.; Edwards, J.; Cropper, M.; Rossi, G.; Halle, A. von; Williams, M.

2002-01-01

The National Spherical Torus Experiment (NSTX) capability with a Neutral Beam Injector (NBI) capable of 80 kiloelectronvolt (keV), 5 Megawatt (MW), 5 second operation. This 5.95 million dollar upgrade reused a previous generation injector and equipment for technical, cost, and schedule reasons to obtain these specifications while retaining a legacy capability of 120 keV neutral particle beam delivery for shorter pulse lengths for possible future NSTX experiments. Concerns with NBI injection included power deposition in the plasma, aiming angles from the fixed NBI fan array, density profiles and beam shine through, orbit losses of beam particles, and protection of the vacuum vessel wall against beam impingement. The upgrade made use of the beamline and cryo panels from the Neutral Beam Test Stand facility, existing power supplies and controls, beamline components and equipment not contaminated by tritium during DT [deuterium-tritium] experiments, and a liquid Helium refrigerator plant to power and cryogenically pump a beamline and three ion sources. All of the Tokamak Fusion Test Reactor (TFTR) ion sources had been contaminated with tritium, so a refurbishment effort was undertaken on selected TFTR sources to rid the three sources destined for the NSTX NBI of as much tritium as possible. An interconnecting duct was fabricated using some spare and some new components to attach the beamline to the NSTX vacuum vessel. Internal vacuum vessel armor using carbon tiles was added to protect the stainless steel vacuum vessel from beam impingement in the absence of plasma and interlock failure. To date, the NBI has operated to 80 keV and 5 MW and has injected requested power levels into NSTX plasmas with good initial results, including high beta and strong heating characteristics at full rated plasma current

Anomalous Beam-Ion Loss in TFTR Reversed Magnetic Shear Plasmas

International Nuclear Information System (INIS)

Ruskov, E.; Bell, M.; Budny, R.V.; McCune, D.C.; Medley, S.S.; Redi, M.H.; Scott, S.; Synakowski, E.J.; Goeler, S. von; White, R.B.; Zweben, S.J.

1999-01-01

Anomalous beam-ion loss has been observed in an experiment with short tritium beam pulses injected into deuterium-beam-heated Tokamak Fusion Test Reactor plasmas (P NBI =15 MW) with reversed magnetic shear (RS). Comparisons of the measured total 14thinspthinspMeV neutron emission, the neutron flux along eight radial locations, and the perpendicular plasma stored energy with predictions from an extensive set of TRANSP simulations suggest that about 40% beam power is lost on a time scale much shorter than the tritium beam pulse length Δt=70 ms. In contrast with recent results [K. Tobita et al., Nucl.Fusion 37, 1583 (1997)] from RS experiments at JT-60U, we were not able to show conclusively that magnetic field ripple is responsible for this anomaly. copyright 1999 The American Physical Society

Operating characteristics of a new ion source for KSTAR neutral beam injection system.

Science.gov (United States)

Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul

2014-02-01

A new positive ion source for the Korea Superconducting Tokamak Advanced Research neutral beam injection (KSTAR NBI-1) system was designed, fabricated, and assembled in 2011. The characteristics of the arc discharge and beam extraction were investigated using hydrogen and helium gas to find the optimum operating parameters of the arc power, filament voltage, gas pressure, extracting voltage, accelerating voltage, and decelerating voltage at the neutral beam test stand at the Korea Atomic Energy Research Institute in 2012. Based on the optimum operating condition, the new ion source was then conditioned, and performance tests were primarily finished. The accelerator system with enlarged apertures can extract a maximum 65 A ion beam with a beam energy of 100 keV. The arc efficiency and optimum beam perveance, at which the beam divergence is at a minimum, are estimated to be 1.0 A/kW and 2.5 uP, respectively. The beam extraction tests show that the design goal of delivering a 2 MW deuterium neutral beam into the KSTAR Tokamak plasma is achievable.

Brayton-Cycle Power-Conversion Unit Tested With Ion Thruster

Science.gov (United States)

Hervol, David S.

2005-01-01

Nuclear electric propulsion has been identified as an enabling technology for future NASA space science missions, such as the Jupiter Icy Moons Orbiter (JIMO) now under study. An important element of the nuclear electric propulsion spacecraft is the power conversion system, which converts the reactor heat to electrical power for use by the ion propulsion system and other spacecraft loads. The electrical integration of the power converter and ion thruster represents a key technical challenge in making nuclear electric propulsion technology possible. This technical hurdle was addressed extensively on December 1, 2003, when a closed- Brayton-cycle power-conversion unit was tested with a gridded ion thruster at the NASA Glenn Research Center. The test demonstrated end-to-end power throughput and marked the first-ever coupling of a Brayton turbo alternator and a gridded ion thruster, both of which are candidates for use on JIMO-type missions. The testing was conducted at Glenn's Vacuum Facility 6, where the Brayton unit was installed in the 3-m-diameter vacuum test port and the ion thruster was installed in the 7.6-m-diameter main chamber.

Capillary Ion Concentration Polarization for Power-Free Salt Purification

Science.gov (United States)

Park, Sungmin; Jung, Yeonsu; Cho, Inhee; Kim, Ho-Young; Kim, Sung Jae

2014-11-01

In this presentation, we experimentally and theoretically demonstrated the capillary based ion concentration polarization for power-free salt purification system. Traditional ion concentration polarization phenomenon has been studied for a decade for both fundamental nanoscale fluid dynamics and novel engineering applications such as desalination, preconcentration and energy harvesting devices. While the conventional system utilizes an external power source, the system based on capillary ion concentration polarization is capable of perm-selective ion transportation only by capillarity so that the same ion depletion zone can be formed without any external power sources. An ion concentration profile near the nanostructure was tracked using fluorescent probes and analyzed by solving the modified Nernst-Planck equation. As a result, the concentration in the vicinity of the nanostructure was at least 10 times lower than that of bulk electrolyte and thus, the liquid absorbed into the nanostructure had the low concentration. This mechanism can be used for the power free salt purification system which would be significantly useful in underdeveloped and remote area. This work was supported by Samsung Research Funding Center of Samsung Electronics under Project Number SRFC-MA1301-02.

An improved electron impact ion source power supply

International Nuclear Information System (INIS)

Beaver, E.M.

1974-01-01

An electron impact ion source power supply has been developed that offers improved ion beam stability. The electrical adjustments of ion source parameters are more flexible, and safety features are incorporated to protect the electron emitting filament from accidental destruction. (author)

The H-mode power threshold in JET

Energy Technology Data Exchange (ETDEWEB)

Start, D F.H.; Bhatnagar, V P; Campbell, D J; Cordey, J G; Esch, H P.L. de; Gormezano, C; Hawkes, N; Horton, L; Jones, T T.C.; Lomas, P J; Lowry, C; Righi, E; Rimini, F G; Saibene, G; Sartori, R; Sips, G; Stork, D; Thomas, P; Thomsen, K; Tubbing, B J.D.; Von Hellermann, M; Ward, D J [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-07-01

New H-mode threshold data over a range of toroidal field and density values have been obtained from the present campaign. The scaling with n{sub e} B{sub t} is almost identical with that of the 91/92 period for the same discharge conditions. The scaling with toroidal field alone gives somewhat higher thresholds than the older data. The 1991/2 database shows a scaling of P{sub th} (power threshold) with n{sub e} B{sub t} which is approximately linear and agrees well with that observed on other tokamaks. For NBI and carbon target tiles the threshold power is a factor of two higher with the ion {Nu}B drift away from the target compared with the value found with the drift towards the target. The combination of ICRH and beryllium tiles appears to be beneficial for reducing P{sub th}. The power threshold is largely insensitive to plasma current, X-point height and distance between the last closed flux surface and the limiter, at least for values greater than 2 cm. (authors). 3 refs., 6 figs.

Measurements of the fast-ion distribution function at ASDEX upgrade by collective Thomson scattering (CTS) using active and passive views

DEFF Research Database (Denmark)

Nielsen, Stefan Kragh; Stejner Pedersen, Morten; Rasmussen, Jesper

2015-01-01

, the measured spectra agree quantitatively with the synthetic spectra in periods with and without NBI heating. For the discharges investigated, the central velocity distribution of neutral beam ions can be described by classical slowing down. These results will have a major impact on ITER physics exploration...... independent heterodyne receiver systems enables subtraction of the additional part from the total spectrum, revealing the resulting CTS spectrum. Here we present CTS measurements from the plasma centre obtained in L-mode and H-mode plasmas with and without neutral beam injection (NBI). For the first time...

High power switches for ion induction linacs

International Nuclear Information System (INIS)

Humphries, S. Jr.; Savage, M.; Saylor, W.B.

1985-01-01

The success of linear induction ion accelerators for accelerator inertial fusion (AIF) applications depends largely on innovations in pulsed power technology. There are tight constraints on the accuracy of accelerating voltage waveforms to maintain a low momentum spread. Furthermore, the non-relativistic ion beams may be subject to a klystron-like interaction with the accelerating cavities leading to enhanced momentum spread. In this paper, the author describe a novel high power switch with a demonstrated ability to interrupt 300 A at 20 kV in less than 60 ns. The switch may allow the replacement of pulse modulators in linear induction accelerators with hard tube pulsers. A power system based on a hard tube pulser could solve the longitudinal instability problem while maintaining high energy transfer efficiency. The problem of longitudinal beam control in ion induction linacs is reviewed in Section 2. Section 3 describes the principles of the plasma flow switch. Experimental results are summarized in Section 4

High power switches for ion induction linacs

International Nuclear Information System (INIS)

Humphries, S.; Savage, M.; Saylor, W.B.

1985-01-01

The success of linear induction ion accelerators for accelerator inertial fusion (AIF) applications depends largely on innovations in pulsed power technology. There are tight constraints on the accuracy of accelerating voltage waveforms to maintain a low momentum spread. Furthermore, the non-relativistic ion beams may be subject to a klystronlike interaction with the accelerating cavities, leading to enhanced momentum spread. In this paper, we describe a novel high power switch with a demonstrated ability to interrupt 300 A at 20 kV in less than 60 ns. The switch may allow the replacement of pulse modulators in linear induction accelerators with hard tube pulsers. A power system based on a hard tube pulser could solve the longitudinal instability problem while maintaining high energy transfer efficiency. The problem of longitudinal beam control in ion induction linacs is reviewed in Section 2. Section 3 describes the principles of the plasma flow switch. Experimental results are summarized in Section 4

Thermal insulation of high confinement mode with dominant electron heating in comparison to dominant ion heating and corresponding changes of torque input

International Nuclear Information System (INIS)

Sommer, Fabian H.D.

2013-01-01

The ratio of heating power going to electrons and ions will undergo a transition from mixed electron and ion heating as it is in current fusion experiments to dominant electron heating in future experiments and reactors. In order to make valid projections towards future devices the connected changes in plasma response and performance are important to be study and understand: Do electron heated plasmas behave systematically different or is the change of heated species fully compensated by heat exchange from electrons to ions? How does particle transport influence the density profile? Is the energy confinement and the H-mode pedestal reduced with reduced torque input? Does the turbulent transport regime change fundamentally? The unique capabilities of the ECRH system at ASDEX Upgrade enable this change of heated species by replacing NBI with ECRH power and thereby offer the possibility to discuss these and other questions. For low heating powers corresponding to high collisionalities the transition from mixed electron and ion heating to pure electron heating showed next to no degradation of the global plasma parameters and no change of the edge values of kinetic profiles. The electron density shows an increased central peaking with increased ECRH power. The central electron temperature stays constant while the ion temperature decreases slightly. The toroidal rotation decreases with reduced NBI fraction, but does not influence the profile stability. The power balance analysis shows a large energy transfer from electrons to ions, so that the electron heat flux approaches zero at the edge whereas the ion heat flux is independent of heating mix. The ion heat diffusivity exceeds the electron one. For high power, low collisionality discharges global plasma parameters show a slight degradation with increasing electron heating. The density profile shows a strong peaking which remains unchanged when modifying the heating mix. The electron temperature profile is unchanged

Power processing systems for ion thrusters.

Science.gov (United States)

Herron, B. G.; Garth, D. R.; Finke, R. C.; Shumaker, H. A.

1972-01-01

The proposed use of ion thrusters to fulfill various communication satellite propulsion functions such as east-west and north-south stationkeeping, attitude control, station relocation and orbit raising, naturally leads to the requirement for lightweight, efficient and reliable thruster power processing systems. Collectively, the propulsion requirements dictate a wide range of thruster power levels and operational lifetimes, which must be matched by the power processing. This paper will discuss the status of such power processing systems, present system design alternatives and project expected near future power system performance.

The next step in a development of negative ion beam plasma neutraliser for ITER NBI

International Nuclear Information System (INIS)

Kulygin, V.M.; Dlougach, E.D.; Gorbunov, E.P.

2001-01-01

Injectors of deuterium atom beams developing for ITER plasma heating and current drive are based on the negative ion acceleration and further neutralization with a gas target. The maximal efficiency of a gas stripping process is 60%. The replacement of the gas neutralizer by plasma one must increase the neutral yield to 80%. The experimental study overview of the microwave discharge in a multi-cusp magnetic system chosen as a base device for Plasma Neutralizer realization and the design development for ITER Neutral Beam Injectors are presented. The experimental results achieved at a plasma neutralizer model PNX-U is discussed. Plasma confinement, gas flows, ionization degree were investigated. The plasma in the volume 0.5m 3 with density n e ∼ 10 18 m -3 has been achieved at power density 80kW/m 3 in operation with Argon. (author)

Radiobromination of anti-HER2/neu/ErbB-2 monoclonal antibody using the p-isothiocyanatobenzene derivative of the [76Br]undecahydro-bromo-7,8-dicarba-nido-undecaborate(1-) ion

International Nuclear Information System (INIS)

Winberg, Karl Johan; Persson, Mikael; Malmstroem, Per-Uno; Sjoeberg, Stefan; Tolmachev, Vladimir

2004-01-01

The monoclonal humanized anti-HER2 antibody trastuzumab was radiolabeled with the positron emitter 76 Br (T ((1)/(2)) =16.2 h). Indirect labeling was performed using the p-isothiocyanatobenzene derivative of the [ 76 Br]undecahydro-bromo-7,8-dicarba-nido-undecaborate(1-) ( 76 Br-NBI) as a precursor molecule. 76 Br-NBI was prepared by bromination of the 7-(p-isothiocyanato-phenyl)dodecahydro-7,8-dicarba-nido-undecaborate(1-) ion (NBI) with a yield of 93-95% using Chloramine-T (CAT) as an oxidant. Coupling of radiobrominated NBI to antibody was performed without intermediate purification, in an ''one pot'' reaction. An overall labeling yield of 55.7 ± 4.8% (mean ± maximum error) was achieved when 300 μg of antibody was labeled. The label was stable in vitro in physiological and denaturing conditions. In a cell binding test, trastuzumab remained immunoreactive after labeling

On-line measurement of microwave power in ECR ion source

International Nuclear Information System (INIS)

Zhou Changgeng; Kang Wu; Hu Yonghong; Li Yan; Lou Benchao; Zu Xiulan; Xiong Riheng; Chen Junguang; Li Xiaoyun

2005-01-01

It is a new technology to apply an ECR ion source to the neutron generator. Because of the structure limitation, working state of the ECR ion source could not be judged by the color of gas discharging in discharge chamber. Therefore, it was hard to estimate if the ECR ion source was working properly in the neutron generator. The method to resolve the problem was described in this paper. The microwave power was measured on-line by a directional coupler and a small microwave power meter. The ion beam current could be educed from the measured incidence microwave power, and discharge state in discharge chamber could be determined. (authors)

Magnetic properties of Aurivillius lanthanide-bismuth (LnFeO3nBi4Ti3O12 (n = 1,2 layered titanates

Directory of Open Access Journals (Sweden)

Tartaj, J.

2008-06-01

Full Text Available Bismuth titanates of Aurivillius layer-structure (BiFeO3nBi4Ti3O12, are of great technological interest because of their applications as non-volatile ferroelectric memories and high-temperature piezoelectric materials. The synthesis and crystallographic characterization of a new family of compounds (LnFeO3nBi4Ti3O12 was recently reported, in which the layers consist of LnFeO3 perovskites with a lanthanide Ln3+ substituting diamagnetic Bi3+. We report herein the magnetic properties of bulk samples, with Ln = Nd, Eu, Gd and Tb, and n = 1 and 2. Single-layer materials are paramagnetic, similar to non-substituted bismuth titanate Bi5FeTi3O15, and show crystal field effects due to the crystallographic environment of Eu3+ and Tb3+. Several anomalies are detected in the magnetization M(T of double-layer (LnFeO32Bi4Ti3O12 compounds, related to the strong magnetism of Tb and Gd, since they weakly appear for Nd and they are absent in the VanVleck Eu3+ ion and in the parent Bi6Fe2Ti3O18 compound.Los titanatos de hierro y bismuto con estructura laminar tipo Aurivillius, (BiFeO3nBi4Ti3O12, tienen un gran interés tecnológico debido a sus aplicaciones como memorias ferroeléctricas no volátiles y como piezoeléctrico cerámico de alta temperatura. La síntesis y la caracterización cristalina de una nueva familia de compuestos (LnFeO3nBi4Ti3O12 han sido recientemente reportadas, en la que el catión diamagnético Bi3+ ha sido sustituido por los paramagnéticos Ln3+ en los bloques de perovskita. Se estudian las propiedades magnéticas de muestras cerámicas en volumen con Ln = Nd, Eu, Gd y Tb, y n = 1 y 2. Los materiales con n=1 son paramagnéticos y similares al no sustituido Bi5FeTi3O15, y muestran efectos de campo cristalino debido al entorno cristalino de Eu3+ y Tb3+. Se han detectado algunas anomalías en la magnetización M(T de los compuestos n=2 (LnFeO32Bi4Ti3O12 que están relacionadas con el fuerte magnetismo de Tb y Gd, que aparecen d

The Role of Combined ICRF and NBI Heating in JET Hybrid Plasmas in Quest for High D-T Fusion Yield

Directory of Open Access Journals (Sweden)

Mantsinen Mervi

2017-01-01

Full Text Available Combined ICRF and NBI heating played a key role in achieving the world-record fusion yield in the first deuterium-tritium campaign at the JET tokamak in 1997. The current plans for JET include new experiments with deuterium-tritium (D-T plasmas with more ITER-like conditions given the recently installed ITER-like wall (ILW. In the 2015-2016 campaigns, significant efforts have been devoted to the development of high-performance plasma scenarios compatible with ILW in preparation of the forthcoming D-T campaign. Good progress was made in both the inductive (baseline and the hybrid scenario: a new record JET ILW fusion yield with a significantly extended duration of the high-performance phase was achieved. This paper reports on the progress with the hybrid scenario which is a candidate for ITER longpulse operation (∼1000 s thanks to its improved normalized confinement, reduced plasma current and higher plasma beta with respect to the ITER reference baseline scenario. The combined NBI+ICRF power in the hybrid scenario was increased to 33 MW and the record fusion yield, averaged over 100 ms, to 2.9x1016 neutrons/s from the 2014 ILW fusion record of 2.3x1016 neutrons/s. Impurity control with ICRF waves was one of the key means for extending the duration of the high-performance phase. The main results are reviewed covering both key core and edge plasma issues.

JET RF dominated scenarios and ion ITB experiments with low external momentum input

International Nuclear Information System (INIS)

Crisanti, F.; Esposito, B.; Gormezano, C.; Buratti, P.; Cardinali, A.; Giovannozzi, E.; Sozzi, C.; Becoulet, A.; Rimini, F.; Garbet, X.; Guirlet, R.; Joffrin, E.; Litaudon, X.; Brambilla, M.; Baar, M. de; Luna, E. de la; Vries, P. de; Giroud, C.; Mantica, P.; Mantsinen, M.; Salmi, A.; Eester, D. van

2005-01-01

Advanced Tokamak scenarios include two different regimes: the 'steady state' (characterized by the presence of an Internal Transport Barrier (ITB)) and the 'hybrid scenario' (characterized by central q > 1 and a large region with magnetic shear close to zero). So far both the regimes, at least for the ion species, have always been obtained in presence of strong injection of external momentum by Neutrals Beam Injection (NBI) heating. By using Lower Hybrid Current Drive (LHCD) to sustain the central q slightly above one and with a large plasma region having the magnetic shear s close to zero, an 'hybrid scenario' has been established, for the first time, in discharges with dominant Ion Cyclotron Resonance Heating (ICRH) and with a normalized beta close to two. By starting from a configuration with reversed magnetic shear (sustained only by LHCD) and with a well established ITB on the electron species, an ITB also on the ions species has been obtained by using ICRH in an ion minority heating scheme, ( 3 He)D. No external momentum input was provided by the NBI, except for the diagnostic charge-exchange and the MSE beams. In these discharges the evaluated ExB shearing rate was always very small (in the noisy range) and lower than analytical evaluations of the turbulence growth rate. (author)

Reconstruction of negative hydrogen ion beam properties from beamline diagnostics

Energy Technology Data Exchange (ETDEWEB)

Ruf, Benjamin

2014-09-25

For the experimental fusion reactor ITER, which should show the feasibility of sustaining a fusion plasma with a positive power balance, some technology still has to be developed, amongst others also the plasma heating system. One heating technique is the neutral beam injection (NBI). A beam of fast deuterium atoms is injected into the fusion plasma. By heavy particle collisions the beam particles give their energy to the plasma. A NBI system consists of three major components. First, deuterium ions are generated in a low temperature, low pressure plasma of an ion source. At ITER, the requirements on the beam energy of 1 MeV cause the necessity of negative charged deuterium ions. Secondly, the ions are accelerated within an acceleration system with several grids, where the plasma grid is the first grid. The grids are on different descending high voltage potentials. The source itself is on the highest negative potential. Thirdly, the fast deuterium ions have to be neutralised. This thesis deals with the second step in the mentioned beam system, the ion acceleration and beam formation. The underlying experiments and measurements were carried out at the testbeds BATMAN (BAvarianTest MAchine for Negative ions) and ELISE (Extraction from a Large Ion Source Experiment) at the Max-Planck-Institut fuer Plasmaphysik Garching (IPP Garching). The main goal of this thesis is to provide a tool which allows the determination of the beam properties. These are beam divergence, stripping losses and beam inhomogeneity. For this purpose a particle trajectory code has been developed from scratch, namely BBC-NI (Bavarian Beam Code for Negative Ions). The code is able to simulate the whole beam and the outcome of several beam diagnostic tools. The data obtained from the code together with the measurements of the beam diagnostic tools should allow the reconstruction of the beam properties. The major beam diagnostic tool, which is used in this thesis, is the beam emission spectroscopy

Power supply system for negative ion source at IPR

Science.gov (United States)

Gahlaut, Agrajit; Sonara, Jashwant; Parmar, K. G.; Soni, Jignesh; Bandyopadhyay, M.; Singh, Mahendrajit; Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun

2010-02-01

The first step in the Indian program on negative ion beams is the setting up of Negative ion Experimental Assembly - RF based, where 100 kW of RF power shall be coupled to a plasma source producing plasma of density ~5 × 1012 cm-3, from which ~ 10 A of negative ion beam shall be produced and accelerated to 35 kV, through an electrostatic ion accelerator. The experimental system is modelled similar to the RF based negative ion source, BATMAN presently operating at IPP, Garching, Germany. The mechanical system for Negative Ion Source Assembly is close to the IPP source, remaining systems are designed and procured principally from indigenous sources, keeping the IPP configuration as a base line. High voltage (HV) and low voltage (LV) power supplies are two key constituents of the experimental setup. The HV power supplies for extraction and acceleration are rated for high voltage (~15 to 35kV), and high current (~ 15 to 35A). Other attributes are, fast rate of voltage rise (< 5ms), good regulation (< ±1%), low ripple (< ±2%), isolation (~50kV), low energy content (< 10J) and fast cut-off (< 100μs). The low voltage (LV) supplies required for biasing and providing heating power to the Cesium oven and the plasma grids; have attributes of low ripple, high stability, fast and precise regulation, programmability and remote operation. These power supplies are also equipped with over-voltage, over-current and current limit (CC Mode) protections. Fault diagnostics, to distinguish abnormal rise in currents (breakdown faults) with over-currents is enabled using fast response breakdown and over-current protection scheme. To restrict the fault energy deposited on the ion source, specially designed snubbers are implemented in each (extraction and acceleration) high voltage path to swap the surge energy. Moreover, the monitoring status and control signals from these power supplies are required to be electrically (~ 50kV) isolated from the system. The paper shall present the

Power supply system for negative ion source at IPR

International Nuclear Information System (INIS)

Gahlaut, Agrajit; Sonara, Jashwant; Parmar, K G; Soni, Jignesh; Bandyopadhyay, M; Singh, Mahendrajit; Bansal, Gourab; Pandya, Kaushal; Chakraborty, Arun

2010-01-01

The first step in the Indian program on negative ion beams is the setting up of Negative ion Experimental Assembly - RF based, where 100 kW of RF power shall be coupled to a plasma source producing plasma of density ∼5 x 10 12 cm -3 , from which ∼ 10 A of negative ion beam shall be produced and accelerated to 35 kV, through an electrostatic ion accelerator. The experimental system is modelled similar to the RF based negative ion source, BATMAN presently operating at IPP, Garching, Germany. The mechanical system for Negative Ion Source Assembly is close to the IPP source, remaining systems are designed and procured principally from indigenous sources, keeping the IPP configuration as a base line. High voltage (HV) and low voltage (LV) power supplies are two key constituents of the experimental setup. The HV power supplies for extraction and acceleration are rated for high voltage (∼15 to 35kV), and high current (∼ 15 to 35A). Other attributes are, fast rate of voltage rise (< 5ms), good regulation (< ±1%), low ripple (< ±2%), isolation (∼50kV), low energy content (< 10J) and fast cut-off (< 100μs). The low voltage (LV) supplies required for biasing and providing heating power to the Cesium oven and the plasma grids; have attributes of low ripple, high stability, fast and precise regulation, programmability and remote operation. These power supplies are also equipped with over-voltage, over-current and current limit (CC Mode) protections. Fault diagnostics, to distinguish abnormal rise in currents (breakdown faults) with over-currents is enabled using fast response breakdown and over-current protection scheme. To restrict the fault energy deposited on the ion source, specially designed snubbers are implemented in each (extraction and acceleration) high voltage path to swap the surge energy. Moreover, the monitoring status and control signals from these power supplies are required to be electrically (∼ 50kV) isolated from the system. The paper shall

Radiobromination of anti-HER2/neu/ErbB-2 monoclonal antibody using the p-isothiocyanatobenzene derivative of the [{sup 76}Br]undecahydro-bromo-7,8-dicarba-nido-undecaborate(1-) ion

Energy Technology Data Exchange (ETDEWEB)

Winberg, Karl Johan; Persson, Mikael; Malmstroem, Per-Uno; Sjoeberg, Stefan; Tolmachev, Vladimir E-mail: Vladimir.Tolmachev@bms.uu.se

2004-05-01

The monoclonal humanized anti-HER2 antibody trastuzumab was radiolabeled with the positron emitter {sup 76}Br (T{sub ((1)/(2))} =16.2 h). Indirect labeling was performed using the p-isothiocyanatobenzene derivative of the [{sup 76}Br]undecahydro-bromo-7,8-dicarba-nido-undecaborate(1-) ({sup 76}Br-NBI) as a precursor molecule. {sup 76}Br-NBI was prepared by bromination of the 7-(p-isothiocyanato-phenyl)dodecahydro-7,8-dicarba-nido-undecaborate(1-) ion (NBI) with a yield of 93-95% using Chloramine-T (CAT) as an oxidant. Coupling of radiobrominated NBI to antibody was performed without intermediate purification, in an ''one pot'' reaction. An overall labeling yield of 55.7 {+-} 4.8% (mean {+-} maximum error) was achieved when 300 {mu}g of antibody was labeled. The label was stable in vitro in physiological and denaturing conditions. In a cell binding test, trastuzumab remained immunoreactive after labeling.

Plasma Heating and Current Drive by Neutral Beam and Alpha Particles

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, M; Okumura, Y [Fusion Research and Development Directorate, Japan Atomic Energy Agency (Japan)

2012-09-15

The purpose of plasma heating is to raise the plasma temperature enough to produce a deuterium and tritium reaction (D + T {yields} {sup 4}He + n). The required plasma temperature T is in the range of 10-30 keV. Since the high temperature plasma is confined by a strong magnetic field, injection of energetic ions from outside to heat the plasma is difficult due to the Lorenz force. The most efficient way to heat the plasma by energetic particles is to inject high energy 'neutrals' which get ionized in the plasma. Neutral beam injection (NBI) with a beam energy much above the average kinetic energy of the plasma electrons or ions is used (beam energy typically {approx}40 keV - 1 MeV). This heating scheme is similar to warming up cold water by pouring in hot water. There are two types of neutral beam, called P-NBI and N-NBI (P- and N- means 'positive' and 'negative', respectively). P-NBI uses the acceleration of positively charged ions and their neutralization, while N-NBI uses the acceleration of negative ions (electrons attached to neutral atoms) and their neutralization. Details are given in NBI technology Section. The first demonstration of plasma heating by P-NBI was made in ORMAK and ATC in 1974, while that by N-NBI was made in JT-60U for the first time in 1996. ITER has also adopted the N-NBI system as the heating and current drive system with a beam energy of 1 MeV. Figure A typical bird's eye view of a tokamak with N-NBI and N-NBI (JT-60U) is shown. (author)

Highly Radiative Plasmas for Local Transport Studies and Power and Particle Handling in Reactor Regimes

International Nuclear Information System (INIS)

Bell, M.G.; Bell, R.E.; Budny, R.; Bush, C.E.; Hill, K.W.

1998-01-01

To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into the Tokamak Fusion Test Reactor (TFTR) supershots and high-l(subscript) plasmas. At neutral beam injection (NBI) powers P(subscript B) greater than or equal to 30 MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both deuterium (D) and deuterium-tritium (DT) plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in the International Thermonuclear Experimental Reactor (ITER). The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms

Review of stopping power and Coulomb explosion for molecular ion in plasmas

Directory of Open Access Journals (Sweden)

Guiqiu Wang

2018-03-01

Full Text Available We summarize our theoretical studies for stopping power of energetic heavy ion, diatomic molecular ions and small clusters penetrating through plasmas. As a relevant research field for the heavy ion inertial confinement fusion (HICF, we lay the emphasis on the dynamic polarization and correlation effects of the constituent ion within the molecular ion and cluster for stopping power in order to disclose the role of the vicinage effect on the Coulomb explosion and energy deposition of molecules and clusters in plasma. On the other hand, as a promising scheme for ICF, both a strong laser field and an intense ion beam are used to irradiate a plasma target. So the influence of a strong laser field on stopping power is significant. We discussed a large range of laser and plasma parameters on the coulomb explosion and stopping power for correlated-ion cluster and C60 cluster. Furthermore, in order to indicate the effects of different cluster types and sizes on the stopping power, a comparison is made for hydrogen and carbon clusters. In addition, the deflection of molecular axis for diatomic molecules during the Coulomb explosion is also given for the cases both in the presence of a laser field and laser free. Finally, a future experimental scheme is put forward to measure molecular ion stopping power in plasmas in Xi'an Jiaotong University of China. Keywords: Molecules, Stopping power, Coulomb explosion, Vicinage effect, Laser, PACS Codes: 34.50.Bw, 52.40.Mj, 61.85.+p, 34.50.Dy

On-line measurement of the microwave power in ECR ion source

International Nuclear Information System (INIS)

Zhou Changgeng; Kang Wu; Hu Yonghong; Li Yan; Lou Benchao; Zu Xiulan; Xiong Riheng; Chen Junguang

2005-01-01

It is a new technology that ECR ion source is applied in the neutron generator. Because of effect of the structure, working state of ECR ion source could not be judged by the color of gas discharging in discharging chamber as doing in high frequency ion source. Therefore, state adjusting of ECR ion source was difficult in running of the neutron generator. The method to resolve the question is described in this paper. The micro-wave power was measured in case of running by using the method of directional coupler adding small microwave power meter. Because both were in the direct proportion, the ion beam current could be educed from microwave incidence power measured, and discharge state in discharge chamber could be judged. Finally, the neutron generator might be operated in best running state. (authors)

Simple emittance measurement of negative hydrogen ion beam using pepper-pot method

International Nuclear Information System (INIS)

Hamabe, M.; Tsumori, K.; Takeiri, Y.; Kaneko, O.; Asano, E.; Kawamoto, T.; Kuroda, T.; Guharay, S.K.

1997-01-01

A simple apparatus for emittance measurement using pepper-pot method is developed. The pepper-pot patterns are directly exposed and recorded on a Kapton foil. Using this apparatus, emittance was measured in the case of the negative hydrogen (H - ) beam from the large negative ion source, which is the 1/3 scaled test device for the negative-ion-based neutral beam injection (N-NBI) on the Large Helical Device (LHD). As the consequence of the first trial, the 95% normalized emittance value is measured as 0.59 mm mrad. (author)

Simple emittance measurement of negative hydrogen ion beam using pepper-pot method

Energy Technology Data Exchange (ETDEWEB)

Hamabe, M.; Tsumori, K.; Takeiri, Y.; Kaneko, O.; Asano, E.; Kawamoto, T.; Kuroda, T. [National Inst. for Fusion Science, Nagoya (Japan); Guharay, S.K.

1997-02-01

A simple apparatus for emittance measurement using pepper-pot method is developed. The pepper-pot patterns are directly exposed and recorded on a Kapton foil. Using this apparatus, emittance was measured in the case of the negative hydrogen (H{sup -}) beam from the large negative ion source, which is the 1/3 scaled test device for the negative-ion-based neutral beam injection (N-NBI) on the Large Helical Device (LHD). As the consequence of the first trial, the 95% normalized emittance value is measured as 0.59 mm mrad. (author)

Feasibility study of an optical resonator for applications in neutral-beam injection systems for the next generation of nuclear fusion reactors

International Nuclear Information System (INIS)

Fiorucci, Donatella

2015-01-01

This work is part of a larger project called SIPHORE (Single gap Photo-neutralizer energy Recovery injector), which aims to enhance the overall efficiency of one of the mechanisms through which the plasma is heated, in a nuclear fusion reactor, i.e. the Neutral Beam Injection (NBI) system. An important component of a NBI system is the neutralizer of high energetic ion beams. SIPHORE proposes to substitute the gas cell neutralizer, used in the current NBI systems, with a photo-neutralizer exploiting the photo-detachment process within Fabry Perot cavities. This mechanism should allow a relevant NBI global efficiency of η≥ 60%, significantly higher than the one currently possible (η≤25% for ITER). The present work concerns the feasibility study of an optical cavity with suitable properties for applications in NBI systems. Within this context, the issue of the determination of an appropriated optical cavity design has been firstly considered and the theoretical and experimental analysis of a particular optical resonator has been carried on. The problems associated with the high levels of intracavity optical power (∼3 MW) required for an adequate photo-neutralization rate have then been faced. In this respect, we addressed both the problem of the thermal effects on the cavity mirrors due to their absorption of intra-cavity optical power (∼1 W) and the one associated to the necessity of a high powerful input laser beam (∼1 kW) to feed the optical resonator. (author)

Fast ion absorption of lower hybrid power in JET

International Nuclear Information System (INIS)

Andrade, M.C.R.; Brusati, M.

1993-01-01

The first experimental evidence at JET on the interaction of fast minority ions with LH is reported. An increase of approximately 20% on the fast ion energy content was observed in the presence of LH, with an estimated LH absorbed power of approximately 20% for 2 MW of LH power and plasma densities of 2.0 to 2.4 x 10 19 m -3 with central temperatures γ ray and neutron rates also show that absorption of LH waves by the fast minority ions is taking place. FFT analysis confirms a better damping of the wave when the overlap between ICRH and LHCD is maximized. (author)

Electronic stopping power of polymers for heavy ions in the ion energy domain of LSS theory

International Nuclear Information System (INIS)

Neetu; Pratibha; Sharma, V.; Diwan, P.K.; Kumar, Shyam

2009-01-01

LSS based computed electronic stopping power values have been compared with the corresponding measured values in polymers for heavy ions with Z = 5-29, in the reduced ion velocity region, v red ≤ 1. Except for limited v red ∼ 0.6-0.85, the formulation generally shows significantly large deviations with the measured values. The ζ factor, which was approximated to be ∼Z 1 1/6 , involved in LSS theory has been suitably modified in the light of the available experimental stopping power data. The calculated stopping power values after incorporating modified ζ in LSS formula have been found to be in close agreement with measured values in various polymers in the reduced ion velocity range 0.35 ≤ v red ≤ 1.0.

Pellet fueling of JET plasmas during ohmic, ICRF and NBI heating

International Nuclear Information System (INIS)

Gondhalekar, A.; Cheetham, A.; Bures, M.

1986-01-01

Pellet fueling experiments have been performed on JET using a single-shot pneumatic injector giving 4.6mm (4.5 x 10 21 D atoms) and 3.6mm (2.2 x 10 21 D atoms) diameter cylindrical deuterium pellets with velocity 0.8 ≤ V(km.s -1 ) ≤ 1.2. Z/sub eff/ 20 m -3 and T/sub e/(0) ≅ 1keV. Separately, high value of n/sub D/(0)tau/sub E/T/sub i/(0) = 1.3 x 10 20 m -3 .s.keV at T/sub i/90) = 6.5keV has been obtained with pellet fueling followed by NBI heating

Energy composition of high-energy neutral beams on the COMPASS tokamak

Directory of Open Access Journals (Sweden)

Mitosinkova Klara

2016-12-01

Full Text Available The COMPASS tokamak is equipped with two identical neutral beam injectors (NBI for additional plasma heating. They provide a beam of deuterium atoms with a power of up to ~(2 × 300 kW. We show that the neutral beam is not monoenergetic but contains several energy components. An accurate knowledge of the neutral beam power in each individual energy component is essential for a detailed description of the beam- -plasma interaction and better understanding of the NBI heating processes in the COMPASS tokamak. This paper describes the determination of individual energy components in the neutral beam from intensities of the Doppler-shifted Dα lines, which are measured by a high-resolution spectrometer viewing the neutral beam-line at the exit of NBI. Furthermore, the divergence of beamlets escaping single aperture of the last accelerating grid is deduced from the width of the Doppler-shifted lines. Recently, one of the NBI systems was modified by the removal of the Faraday copper shield from the ion source. The comparison of the beam composition and the beamlet divergence before and after this modification is also presented.

Interaction of Fast Ions with Global Plasma Modes in the C-2 Field Reversed Configuration Experiment

Science.gov (United States)

Smirnov, Artem; Dettrick, Sean; Clary, Ryan; Korepanov, Sergey; Thompson, Matthew; Trask, Erik; Tuszewski, Michel

2012-10-01

A high-confinement operating regime [1] with plasma lifetimes significantly exceeding past empirical scaling laws was recently obtained by combining plasma gun edge biasing and tangential Neutral Beam Injection (NBI) in the C-2 field-reversed configuration (FRC) experiment [2, 3]. We present experimental and computational results on the interaction of fast ions with the n=2 rotational and n=1 wobble modes in the C-2 FRC. It is found that the n=2 mode is similar to quadrupole magnetic fields in its detrimental effect on the fast ion transport due to symmetry breaking. The plasma gun generates an inward radial electric field, thus stabilizing the n=2 rotational instability without applying the quadrupole magnetic fields. The resultant FRCs are nearly axisymmetric, which enables fast ion confinement. The NBI further suppresses the n=2 mode, improves the plasma confinement characteristics, and increases the plasma configuration lifetime [4]. The n=1 wobble mode has relatively little effect on the fast ion transport, likely due to the approximate axisymmetry about the displaced plasma column. [4pt] [1] M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012).[0pt] [2] M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010).[0pt] [3] H.Y. Guo et al., Phys. Plasmas 18, 056110 (2011).[0pt] [4] M. Tuszewski et al., Phys. Plasmas 19, 056108 (2012)

Conceptual design of the beam source for the DEMO Neutral Beam Injectors

Science.gov (United States)

Sonato, P.; Agostinetti, P.; Fantz, U.; Franke, T.; Furno, I.; Simonin, A.; Tran, M. Q.

2016-12-01

DEMO (DEMOnstration Fusion Power Plant) is a proposed nuclear fusion power plant that is intended to follow the ITER experimental reactor. The main goal of DEMO will be to demonstrate the possibility to produce electric energy from the fusion reaction. The injection of high energy neutral beams is one of the main tools to heat the plasma up to fusion conditions. A conceptual design of the Neutral Beam Injector (NBI) for the DEMO fusion reactor, is currently being developed by Consorzio RFX in collaboration with other European research institutes. High efficiency and low recirculating power, which are fundamental requirements for the success of DEMO, have been taken into special consideration for the DEMO NBI. Moreover, particular attention has been paid to the issues related to reliability, availability, maintainability and inspectability. A conceptual design of the beam source for the DEMO NBI is here presented featuring 20 sub-sources (two adjacent columns of 10 sub-sources each), following a modular design concept, with each sub-source featuring its radio frequency driver, capable of increasing the reliability and availability of the DEMO NBI. Copper grids with increasing size of the apertures have been adopted in the accelerator, with three main layouts of the apertures (circular apertures, slotted apertures and frame-like apertures for each sub-source). This design, permitting to significantly decrease the stripping losses in the accelerator without spoiling the beam optics, has been investigated with a self-consistent model able to study at the same time the magnetic field, the electrostatic field and the trajectory of the negative ions. Moreover, the status on the R&D carried out in Europe on the ion sources is presented.

Effects of high power ion Bernstein waves on a tokamak plasma

International Nuclear Information System (INIS)

Ono, M.; Beiersdorfer, P.; Bell, R.

1987-04-01

Ion Bernstein wave heating (IBWH) has been investigated on PLT with up to 650 kW of rf power coupled to the plasma, exceeding the ohmic power of 550 kW. Plasma antenna loading of 2 Ω has been observed, resulting in 80 to 90% of the rf power being coupled to the plasma. An ion heating efficiency of ΔT/sub i/(0)n/sub e//P/sub rf/ = 6 x 10 13 eV cm -3 /kW, without high energy tail ions, has been observed up to the maximum rf power. The deuterium particle confinement during high power IBWH increases significantly (as much as 300%). Associated with it, a longer injected impurity confinement time, reduced drift wave turbulence activity, frequency shifts of drfit wave turbulence, and development of a large negative edge potential were observed. The energy confinement time, however, shows some degradation from the ohmic value, which can be attributed to the enhanced radiation loss observed during IBWH. The ion heating and energy confinement time are relatively independent of plasma current

Electronic stopping power of polymers for heavy ions in the ion energy domain of LSS theory

Energy Technology Data Exchange (ETDEWEB)

Neetu [Department of Physics, Kurukshetra University, Kurukshetra 136 119, Haryana (India)], E-mail: neetuphy@gmail.com; Pratibha [Department of Physics, Kurukshetra University, Kurukshetra 136 119, Haryana (India); Sharma, V. [Department of Physics, Lovely Professional University, Phagwara 144 402 (India); Diwan, P.K. [Department of Physics, U.I.E.T., Kurukshetra University, Kurukshetra 136119, Haryana (India); Kumar, Shyam [Department of Physics, Kurukshetra University, Kurukshetra 136 119, Haryana (India)

2009-04-15

LSS based computed electronic stopping power values have been compared with the corresponding measured values in polymers for heavy ions with Z = 5-29, in the reduced ion velocity region, v{sub red} {<=} 1. Except for limited v{sub red} {approx} 0.6-0.85, the formulation generally shows significantly large deviations with the measured values. The {zeta} factor, which was approximated to be {approx}Z{sub 1}{sup 1/6}, involved in LSS theory has been suitably modified in the light of the available experimental stopping power data. The calculated stopping power values after incorporating modified {zeta} in LSS formula have been found to be in close agreement with measured values in various polymers in the reduced ion velocity range 0.35 {<=} v{sub red} {<=} 1.0.

The light ion pulsed power induction accelerator for ETF

International Nuclear Information System (INIS)

Mazarakis, M.G.; Olson, R.E.; Olson, C.L.; Smith, D.L.; Bennett, L.F.

1994-01-01

Our Engineering Test Facility (ETF) driver concept is based on HERMES III and RHEPP technologies. Actually, it is a scaled-down version of the LMF design incorporating repetition rate capabilities of up to 10 Hz CW. The preconceptual design presented here provides 200-TW peak power to the ETF target during 10 ns, equal to 2-MJ total ion beam energy. Linear inductive voltage addition driving a self-magnetically insulated transmission line (MITL) is utilized to generate the 36-MV peak voltage needed for lithium ion beams. The ∼ 3-MA ion current is achieved by utilizing many accelerating modules in parallel. Since the current per module is relatively modest (∼300 kA), two-stage or one-stage extraction diodes can be utilized for the generation of singly charged lithium ions. The accelerating modules are arranged symmetrically around the fusion chamber in order to provide uniform irradiation onto the ETF target. In addition, the modules are fired in a programmed sequence in order to generate the optimum power pulse shape onto the target. This design utilizes RHEPP accelerator modules as the principal power source

Thermo-mechanical analysis of an acceleration grid for the international thermonuclear experimental reactor-neutral beam injection system

International Nuclear Information System (INIS)

Fujiwara, Yukio; Hanada, Masaya; Okumura, Yoshikazu; Suzuki, Satoshi; Watanabe, Kazuhiro

2001-01-01

In the engineering design of a negative-ion beam source for a high-power neutral beam injection (NBI) system, one of the most important issues is thermo-mechanical design of acceleration grids for producing several tens of MW ion beams. An acceleration grid for the international thermonuclear experimental reactor-neutral beam injection (ITER-NBI) system will be subjected to the heat loading as high as 1.5 MW. In the present paper, thermo-mechanical characteristics of the acceleration grid for the ITER-NBI system were analyzed. Numerical simulation indicated that maximum aperture-axis displacement of the acceleration grid due to thermal expansion would be about 0.7 mm for the heat loading of 1.5 MW. From the thin lens theory of beam optics, beamlet deflection angle by the aperture-axis displacement was estimated to be about 2 mrad, which is within the requirement of the engineering design of the ITER-NBI system. Numerical simulation also indicated that no melting on the acceleration grid would occur for a heat loading of 1.5 MW, while local plastic deformation would happen. To avoid the plastic deformation, it is necessary to reduce the heat loading onto the acceleration grid to less than 1 MW

Simultaneous wide-range stopping power determination for several ions

Energy Technology Data Exchange (ETDEWEB)

Alanko, T. E-mail: tommi.alanko@phys.jyu.fi; Trzaska, W.H.; Lyapin, V.; Raeisaenen, J.; Tiourine, G.; Virtanen, A

2002-05-01

A new procedure to extract simultaneously continuous stopping power curves for several ions and several absorbers over a wide energy range and with statistical errors reduced to negligible level is presented. The method combines our novel time-of-flight based method with the capability of our K130 cyclotron and ECR ion-source to produce the so-called ion cocktails. The potential of the method is demonstrated with a 6.0 MeV/u cocktail consisting of {sup 16}O{sup 4+}, {sup 28}Si{sup 7+} and {sup 40}Ar{sup 10+} ions. The stopping power in polycarbonate in the energy range of 0.35-5 MeV/u has been determined with absolute uncertainty of less than 2.3% and with relative below 0.2%. The results are compared with literature data and with SRIM2000 parameterisation including cores and bonds corrections.

The compact mirrors with high pressure plasmas

International Nuclear Information System (INIS)

Anikeev, A.V.; Bagryansky, P.A.; Ivanov, A.A.; Lizunov, A.A.; Murakhtin, S.V.; Prikhodko, V.V.; Collatz, S.; Noack, K.

2004-01-01

The gas dynamic trap (GDP) experimental facility at the Budker Institute Novosibirsk is a long axial-symmetric mirror system with a high mirror ratio variable in the range of 12.5 - 100 for the confinement of a two-component plasma. One component is a collisional plasma with ion and electron temperatures up to 100 eV and density up to 10 14 cm -3 . The second component is the population of high-energetic fast ions with energies of 2-18 keV and a density up to 10 13 cm -3 which is produced by neutral beam injection (NBI). GDP is currently undergoing an upgrade whose first stage is the achievement of the synthesized hot ion plasmoid experiment (SHIP). This experiment aims at the investigation of plasmas and at the knowledge of plasma parameters that have never been achieved before in magnetic mirrors. The paper presents the physical concept of the SHIP experiment, the results of numerical pre-calculations and draws conclusions regarding possible scenarios of experiments. The simulation of a maximal NBI power regime with hydrogen injection gave a fast ion density of 1.2*10 14 cm -3 with a mean energy of 14 keV. The calculation of the deuterium injection regime with 2 MW NBI power gave a maximal fast ion density of 1.9*10 14 cm -3 with a beam energy of 9 keV. The calculation of an experimental scenario with reduced magnetic field resulted in a maximal β-value of 62%, so this regime is recommended for the study of high-β effects in plasmas confined in axial-symmetric mirrors

Silicon Carbide Power Device Performance Under Heavy-Ion Irradiation

Science.gov (United States)

Lauenstein, Jean-Marie; Casey, Megan; Topper, Alyson; Wilcox, Edward; Phan, Anthony; Ikpe, Stanley; LaBel, Ken

2015-01-01

Heavy-ion induced degradation and catastrophic failure data for SiC power MOSFETs and Schottky diodes are examined to provide insight into the challenge of single-event effect hardening of SiC power devices.

Sol-Gel-Hydrothermal Synthesis of the Heterostructured TiO2/N-Bi2WO6 Composite with High-Visible-Light- and Ultraviolet-Light-Induced Photocatalytic Performances

Directory of Open Access Journals (Sweden)

Jiang Zhang

2012-01-01

Full Text Available The heterostructured TiO2/N-Bi2WO6 composites were prepared by a facile sol-gel-hydrothermal method. The phase structures, morphologies, and optical properties of the samples were characterized by using X-ray powder diffraction (XRD, scanning electron microscopy (SEM, high-resolution transmission electron microscopy (HRTEM, energy dispersive spectroscopy (EDS, and UV-vis diffuse reflectance spectroscopy. The photocatalytic activities for rhodamine B of the as-prepared products were measured under visible and ultraviolet light irradiation at room temperature. The TiO2/N-Bi2WO6 composites exhibited much higher photocatalytic performances than TiO2 as well as Bi2WO6. The enhancement in the visible light photocatalytic performance of the TiO2/N-Bi2WO6 composites could be attributed to the effective electron-hole separations at the interfaces of the two semiconductors, which facilitate the transfer of the photoinduced carriers.

Design of ion-pump power supply control software system based on TCP/IP protocol

International Nuclear Information System (INIS)

Lin Feiyu; Huang Jijiang; Guo Yuhui; Fang Zheng; Wang Yanyu

2009-01-01

This paper discuss a Ion-pump Power Supply control system making use of RS232 series bus and Intranet. The system's hardware VAC800 is composed of MSP430F149 mixed-signal processors produced by TI and UA7000A network model. MSP430F149 has advantages of ultra-low-power and high-integration. The Ion-pump Power Supply control system has the characteristics of strong function, simple structure, high reliability, strong resistance of noise, no peripheral chip, etc. Visual studio 2005 is used to design the system's software. The Ion-pump Power supplier control system can remotely monitor and control Ion-pump Power Suppliers. (authors)

Fluctuations observed in NBI heated Doublet III divertor discharges

International Nuclear Information System (INIS)

Konoshima, Shigeru; Aikawa, Hiroshi; Azumi, Masafumi

1983-10-01

A specific type of activity associated with fairly large pulsive energy loss has been observed, predominantly during improved confinement (H-mode) discharges in the NBI heated Doublet III tokamak. Large repetitive bursts of edge recycling light with 2-5ms duration and --10ms intervals appear in the course of increasing βsub(p). The amount of energy released by a single burst is estimated to be at least 2-3% of stored energy. As a result of these periodic energy losses, attained values of plasma energy is evaluated to be depressed as much as 10%. Prior to a burst, large m=n=0 magnetic field oscillations of --20kHz were observed with highly peaked distribution near the divertor region. No other particular activities which might be responsible for either the confinement deterioration or improvement have been found throughout the entire operational space. (author)

High-Power Ion Thruster Technology

Science.gov (United States)

Beattie, J. R.; Matossian, J. N.

1996-01-01

Performance data are presented for the NASA/Hughes 30-cm-diam 'common' thruster operated over the power range from 600 W to 4.6 kW. At the 4.6-kW power level, the thruster produces 172 mN of thrust at a specific impulse of just under 4000 s. Xenon pressure and temperature measurements are presented for a 6.4-mm-diam hollow cathode operated at emission currents ranging from 5 to 30 A and flow rates of 4 sccm and 8 sccm. Highly reproducible results show that the cathode temperature is a linear function of emission current, ranging from approx. 1000 C to 1150 C over this same current range. Laser-induced fluorescence (LIF) measurements obtained from a 30-cm-diam thruster are presented, suggesting that LIF could be a valuable diagnostic for real-time assessment of accelerator-arid erosion. Calibration results of laminar-thin-film (LTF) erosion badges with bulk molybdenum are presented for 300-eV xenon, krypton, and argon sputtering ions. Facility-pressure effects on the charge-exchange ion current collected by 8-cm-diam and 30-cm-diam thrusters operated on xenon propellant are presented to show that accel current is nearly independent of facility pressure at low pressures, but increases rapidly under high-background-pressure conditions.

Experimental challenges to stiffness as a transport paradigm

Science.gov (United States)

Luce, T. C.; Burrell, K. H.; Holland, C.; Marinoni, A.; Petty, C. C.; Smith, S. P.; Austin, M. E.; Grierson, B. A.; Zeng, L.

2018-02-01

Two power scans were carried out in H-mode plasmas in DIII-D; one employed standard co-current neutral beam injection (NBI), while the other used a mixture of co-current and counter-current NBI to scan power while holding the torque to a low fixed value. Analysis of the ion and electron heat transport, ion toroidal angular momentum transport, and thermal deuterium transport from these scans is presented. Invariance of the gradients or gradient scalelengths, as might be expected from stiff transport, was not generally observed. When invariance was seen, it was not accompanied by a strong increase in transport, except in the case of the absolute deuterium ion transport. Conduction in the ion channel is the dominant energy loss mechanism. The variation of the ion heat transport with applied power is similar for the co-injection and fixed torque scans, indicating that E  ×  B shearing is not determining the plasma response to additional power. There is however, a quantitative difference in the transport between the two scans, indicating E  ×  B shearing does play a role in the transport. Comparison of these results with a previous experiment that directly probed stiffness at a single radius leads to the following conclusion: while local stiffness as formally defined may hold, invariance of the gradients or normalized scalelengths does not follow from stiff transport in more practical scaling experiments, such as the power scans discussed here. Possible reasons for the lack of correspondence between the local picture and the global expectations are discussed.

Electron stripping cross sections for light impurity ions in colliding with atomic hydrogens relevant to fusion research

International Nuclear Information System (INIS)

Tawara, H.

1992-04-01

Electron stripping (ionization) cross sections for impurity (carbon) ions with various charge states in collisions with atomic hydrogens have been surveyed. It has been found that these data are relatively limited both in collision energy and charge state and, in particular those necessary for high energy neutral beam injection (NBI) heating in fusion plasma research are scarce. Some relevant cross sections for carbon ions, C q+ (q = 0-5) have been estimated, based upon the existing data, empirical behavior and electron impact ionization data. (author)

Sizing of lithium-ion stationary batteries for nuclear power plant use

International Nuclear Information System (INIS)

Exavier, Zakaria Barie; Chang, Choong-koo

2017-01-01

Class 1E power system is very essential in preventing significant release of radioactive materials to the environment. Batteries are designed to provide control power for emergency operation of safety-related equipment or equipment important to safety, including power for automatic operation of the Reactor Protection System (RPS) and Engineered Safety Features (ESF) protection systems during abnormal and accident conditions through associated inverters. Technical challenges that are involved in the life cycle of batteries used in the nuclear power plants (NPP) are significant. The extension of dc battery backup time used in the dc power supply system of the Nuclear Power Plants also remains a challenge. The lead acid battery is the most popular utilized at the present. And it is generally the most popular energy storage device, because of its low cost and wide availability. The lead acid battery is still having some challenges since many phenomenon are occurred inside the battery during its lifecycle. The image of Lithium-ion battery in 1991 is considered as alternative for lead acid battery due to better performance which Lithium-ion has over Lead acid. It has high energy density and advanced gravimetric and volumetric properties. It is known that industrial standards for the stationary Lithium-Ion battery are still under development. The aim of this paper is to investigate the possibility of replacing of lead acid battery with lithium-ion battery. To study the ongoing research activities and ongoing developed industrial standards for Lithium-ion battery and suggest the method for sizing including, capacity, dimensions, operational conditions, aging factor and safety margin for NPP use. (author)

Predictive Simulations of ITER Including Neutral Beam Driven Toroidal Rotation

International Nuclear Information System (INIS)

Halpern, Federico D.; Kritz, Arnold H.; Bateman, G.; Pankin, Alexei Y.; Budny, Robert V.; McCune, Douglas C.

2008-01-01

Predictive simulations of ITER [R. Aymar et al., Plasma Phys. Control. Fusion 44, 519 2002] discharges are carried out for the 15 MA high confinement mode (H-mode) scenario using PTRANSP, the predictive version of the TRANSP code. The thermal and toroidal momentum transport equations are evolved using turbulent and neoclassical transport models. A predictive model is used to compute the temperature and width of the H-mode pedestal. The ITER simulations are carried out for neutral beam injection (NBI) heated plasmas, for ion cyclotron resonant frequency (ICRF) heated plasmas, and for plasmas heated with a mix of NBI and ICRF. It is shown that neutral beam injection drives toroidal rotation that improves the confinement and fusion power production in ITER. The scaling of fusion power with respect to the input power and to the pedestal temperature is studied. It is observed that, in simulations carried out using the momentum transport diffusivity computed using the GLF23 model [R.Waltz et al., Phys. Plasmas 4, 2482 (1997)], the fusion power increases with increasing injected beam power and central rotation frequency. It is found that the ITER target fusion power of 500 MW is produced with 20 MW of NBI power when the pedesta temperature is 3.5 keV. 2008 American Institute of Physics. [DOI: 10.1063/1.2931037

Sawtooth control in fusion plasmas

International Nuclear Information System (INIS)

Graves, J P; Angioni, C; Budny, R V; Buttery, R J; Coda, S; Eriksson, L-G; Gimblett, C G; Goodman, T P; Hastie, R J; Henderson, M A; Koslowski, H R; Mantsinen, M J; Martynov, An; Mayoral, M-L; Mueck, A; Nave, M F F; Sauter, O; Westerhof, E

2005-01-01

Clear observations of early triggering of neo-classical tearing modes by sawteeth with long quiescent periods have motivated recent efforts to control, and in particular destabilize, sawteeth. One successful approach explored in TCV utilizes electron cyclotron heating in order to locally increase the current penetration time in the core. The latter is also achieved in various machines by depositing electron cyclotron current drive or ion cyclotron current drive close to the q = 1 rational surface. Crucially, localized current drive also succeeds in destabilizing sawteeth which are otherwise stabilized by a co-existing population of energetic trapped ions in the core. In addition, a recent reversed toroidal field campaign at JET demonstrates that counter-neutral beam injection (NBI) results in shorter sawtooth periods than in the Ohmic regime. The clear dependence of the sawtooth period on the NBI heating power and the direction of injection also manifests itself in terms of the toroidal plasma rotation, which consequently requires consideration in the theoretical interpretation of the experiments. Another feature of NBI, expected to be especially evident in the negative ion based neutral beam injection (NNBI) heating planned for ITER, is the parallel velocity asymmetry of the fast ion population. It is predicted that a finite orbit effect of asymmetrically distributed circulating ions could strongly modify sawtooth stability. Furthermore, NNBI driven current with non-monotonic profile could significantly slow down the evolution of the safety factor in the core, thereby delaying sawteeth

Sawtooth control in fusion plasmas

Science.gov (United States)

Graves, J. P.; Angioni, C.; Budny, R. V.; Buttery, R. J.; Coda, S.; Eriksson, L.-G.; Gimblett, C. G.; Goodman, T. P.; Hastie, R. J.; Henderson, M. A.; Koslowski, H. R.; Mantsinen, M. J.; Martynov, An; Mayoral, M.-L.; Mück, A.; Nave, M. F. F.; Sauter, O.; Westerhof, E.; Contributors, JET–EFDA

2005-12-01

Clear observations of early triggering of neo-classical tearing modes by sawteeth with long quiescent periods have motivated recent efforts to control, and in particular destabilize, sawteeth. One successful approach explored in TCV utilizes electron cyclotron heating in order to locally increase the current penetration time in the core. The latter is also achieved in various machines by depositing electron cyclotron current drive or ion cyclotron current drive close to the q = 1 rational surface. Crucially, localized current drive also succeeds in destabilizing sawteeth which are otherwise stabilized by a co-existing population of energetic trapped ions in the core. In addition, a recent reversed toroidal field campaign at JET demonstrates that counter-neutral beam injection (NBI) results in shorter sawtooth periods than in the Ohmic regime. The clear dependence of the sawtooth period on the NBI heating power and the direction of injection also manifests itself in terms of the toroidal plasma rotation, which consequently requires consideration in the theoretical interpretation of the experiments. Another feature of NBI, expected to be especially evident in the negative ion based neutral beam injection (NNBI) heating planned for ITER, is the parallel velocity asymmetry of the fast ion population. It is predicted that a finite orbit effect of asymmetrically distributed circulating ions could strongly modify sawtooth stability. Furthermore, NNBI driven current with non-monotonic profile could significantly slow down the evolution of the safety factor in the core, thereby delaying sawteeth.

Lithium Ion Batteries Ageing Analysis when used in a PV Power Plants

DEFF Research Database (Denmark)

Beltran, H.; Swierczynski, Maciej Jozef; Aparicio, N.

2012-01-01

This paper analyzes the integration of lithium ion (Li-ion) batteries into large scale grid-connected PV plants. It performs a systematic analysis on both the operation improvement obtained by a PV+ES power plant and the ageing experienced by the Li-ion batteries used as Energy Storage (ES) system...... when operating under different energy management strategies (EMS). In this paper, the PV+ES power plant structure is presented and the selection of Li-on batteries as ES system (ESS) is justified. Moreover, the simulation model used for studying the Li-ion battery ageing is explained and tested...

Ion Stopping Powers and Ranges Whenever You Need Them

DEFF Research Database (Denmark)

Bassler, Niels; Christensen, Casper; Tørresø, Jesper Rosholm

A new app "Electronic Stopping Power" for Android mobile phones and tablets, looks up stopping powers using the ICRU 49 (protons and alphas) and the revised ICRU 73 (lithium and heavier ions) tables. In addition, also MSTAR and an implementation of the Bethe equation expanded to low energies...

New developments in stopping power for fast ions

International Nuclear Information System (INIS)

Paul, Helmut

2007-01-01

We discuss the available stopping power tables and codes, and new experimental methods. Among the semi-empirical stopping power tables, SRIM and MSTAR describe experimental data best. Of the recent theoretical stopping codes CasP, PASS, TCS and dielectric formalism, all describe some data well. PASS is the only theoretical code with an extended table for many ions and targets, but on the average, its predictive value at low energies is less than that of SRIM or MSTAR. The first-principle extended classical trajectory Monte Carlo method is very promising. The ToF-E ERDA arrangements have made it possible to produce accurate data for many ion-target combinations. A new liquid jet target method promises data for liquid water which is an important substance for medical dosimetry

Advanced Electrodes for High Power Li-ion Batteries

Directory of Open Access Journals (Sweden)

Christian M. Julien

2013-03-01

Full Text Available While little success has been obtained over the past few years in attempts to increase the capacity of Li-ion batteries, significant improvement in the power density has been achieved, opening the route to new applications, from hybrid electric vehicles to high-power electronics and regulation of the intermittency problem of electric energy supply on smart grids. This success has been achieved not only by decreasing the size of the active particles of the electrodes to few tens of nanometers, but also by surface modification and the synthesis of new multi-composite particles. It is the aim of this work to review the different approaches that have been successful to obtain Li-ion batteries with improved high-rate performance and to discuss how these results prefigure further improvement in the near future.

Effect of magnetic configuration on frequency of NBI-driven Alfvén modes in TJ-II

Science.gov (United States)

Melnikov, A. V.; Ochando, M.; Ascasibar, E.; Castejon, F.; Cappa, A.; Eliseev, L. G.; Hidalgo, C.; Krupnik, L. I.; Lopez-Fraguas, A.; Liniers, M.; Lysenko, S. E.; de Pablos, J. L.; Perfilov, S. V.; Sharapov, S. E.; Spong, D. A.; Jimenez, J. A.; Ufimtsev, M. V.; Breizman, B. N.; HIBP Group; the TJ-II Team

2014-12-01

Excitation of modes in the Alfvénic frequency range, 30 kHz values, 1.51advantage of the unique TJ-II capabilities, a dynamic magnetic configuration experiment with \\unicode{7548} (ρ , t) variation during discharges has shown strong effects on the mode frequency via both vacuum \\unicode{7548} changes and induced net plasma current. A drastic frequency increase from ˜50 to ˜250 kHz was observed for some modes when plasma current as low as ±2 kA was induced by small (10%) changes in the vertical field. A comprehensive set of diagnostics including a heavy ion beam probe, magnetic probes and a multi-chord bolometer made it possible to identify the spatial spread of the modes and deduce the internal amplitudes of their plasma density and magnetic field perturbations. A simple analytical model for fAE, based on the local Alfvén eigenmode (AE) dispersion relation, was proposed to characterize the observation. It was shown that all the observations, including vacuum iota and plasma current variations, may be fitted by the model, so the linear mode frequency dependence on \\unicode{7548} (plasma current) and one over square root density dependence present the major features of the NBI-induced AEs in TJ-II, and provide the framework for further experiment-to-theory comparison.

Power deposition by neutral beam injected fast ions in field-reversed configurations

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasaka, Naotaka

2004-04-01

Effects of Coulomb collisions on neutral beam (NB) injected fast ions into Field-Reversed Configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing down and pitch angle collisions. The Monte-Carlo method is used for the pitch angle scattering, and the friction term is added to the equation of motion to show effects of slowing down collision such as the deposited power profile. Calculation parameters used are relevant to the NB injection on the FRC Injection Experiment (FIX) device. It is found that the dominant local power deposition occurs in the open field region between the X-point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found negligible. The loss mechanism due to non-adiabatic fast ion motion, which is intrinsic in non-uniform FRC plasmas, affects much greater than the pitch angle scattering by Coulomb collision. (author)

Telescope-based cavity for negative ion beam neutralization in future fusion reactors.

Science.gov (United States)

Fiorucci, Donatella; Hreibi, Ali; Chaibi, Walid

2018-03-01

In future fusion reactors, heating system efficiency is of the utmost importance. Photo-neutralization substantially increases the neutral beam injector (NBI) efficiency with respect to the foreseen system in the International Thermonuclear Experimental Reactor (ITER) based on a gaseous target. In this paper, we propose a telescope-based configuration to be used in the NBI photo-neutralizer cavity of the demonstration power plant (DEMO) project. This configuration greatly reduces the total length of the cavity, which likely solves overcrowding issues in a fusion reactor environment. Brought to a tabletop experiment, this cavity configuration is tested: a 4 mm beam width is obtained within a ≃1.5  m length cavity. The equivalent cavity g factor is measured to be 0.038(3), thus confirming the cavity stability.

High-power ion-cyclotron-resonance heating in the Wisconsin Levitated Octupole

International Nuclear Information System (INIS)

Fortgang, C.M.

1983-05-01

Ion cyclotron resonance heating has been investigated, both experimentally and theoretically, on the Wisconsin Levitated Octupole. Heating of both ions and electrons has been observed. Typically, a two component ion energy distribution is produced (300 eV and 50 eV) with the application of 500 kW of rf power into a 5 x 10 12 cm -3 density plasma. Power is coupled to the plasma with an antenna that also serves as the inductor of an oscillator tank circuit. The oscillator is tunable from 1 to 3 MHz and can be applied for periods up to 10 msec. The experiments were performed with hydrogen, gun injected plasmas

Power consumption in positive ion beam converter with electrostatic electron suppressor

International Nuclear Information System (INIS)

Hashimoto, Kiyoshi; Sugawara, Tohru

1985-01-01

The power recovery characteristics of an in-line direct beam converter provided with electrostatic electron suppressor were studied numerically by tracing the orbits of fast primary ions and secondary charged particles generated along their beam path by collision with background gas molecules. It is shown that, in reference to the electrostatic field potential at the point of impact, the energy distribution of secondary ions impinging on the suppressor has two peaks-one corresponding to a zone of high positive potential surrounding the collector and the other to one of slightly negative potential around the electron suppressor. Secondary electron emission from the suppressor is ascribed mainly to the latter peak, associated with impingement of slower secondary ions. Far much power consumed in secondary particle acceleration is spent for emitting electrons from the suppressor than for secondary ions generated by beam-gas collision. The upper limit of background pressure is discussed on the basis of criteria prescribed for restricting the power consumed in this secondary particle acceleration, as for practical convenience of electrode cooling. Numerical examples are given of calculations based on particle trajectory analysis of both primary ions and secondary particles, for the case of a 100 keV-proton sheet beam 10 cm thick of 35 mA/cm 2 current density. (author)

Effect of resonant microwave power on a PIG ion source

International Nuclear Information System (INIS)

Brown, I.G.; Galvin, J.E.; Gavin, B.F.; MacGill, R.A.

1984-08-01

We have investigated the effect of applying microwave power at the electron cyclotron frequency on the characteristics of the ion beam extracted from a hot-cathode PIG ion source. No change was seen in the ion charge state distribution. A small but significant reduction in the beam noise level was seen, and it is possible that the technique may find application in situations where beam quiescence is important. 29 references, 2 figures

Power deposition for ion cyclotron heating in large tokamaks

International Nuclear Information System (INIS)

Hellsten, T.; Villard, L.

1988-01-01

The power deposition profiles during minority ion cyclotron heating are analysed in large tokamaks by using the global, toroidal wave code LION. For tokamaks with large aspect ratio and with circular cross-section, the wave is focused on the magnetic axis and can be absorbed there by cyclotron absorption when the cyclotron resonance passes through the magnetic axis. The power deposition profile is then essentially determined by the Doppler broadening of the ion cyclotron resonance. For equilibria either non-circular or with a small aspect ratio the power deposition profile depends also on the strength of the damping. In this case the power deposition profile can be expressed as a sum of two power deposition profiles. One is related to the power absorbed in a single pass, and its shape is similar to that obtained for large aspect ratio and circular cross-section. The other profile is obtained by calculating the power deposition in the limit of weak damping, in which case the wave electric field is almost constant along the cyclotron resonance layer. A heuristic formula for the power deposition is given. The formula includes a number of calibration curves and functions which has been calculated with the LION code for JET relevant equilibria. The formula enables calculation of the power deposition profile in a simple way when the launched wave spectrum and damping coefficients are known. (author). 7 refs, 11 figs

Status of the ELISE test facility

International Nuclear Information System (INIS)

Franzen, P.; Wünderlich, D.; Riedl, R.; Nocentini, R.; Fantz, U.; Fröschle, M.; Heinemann, B.; Martens, C.; Kraus, W.; Ruf, B.; Bonomo, F.; Pimazzoni, A.

2015-01-01

The test facility ELISE, equipped with a large radio frequency (RF) driven ion source (1×0.9 m2) of half the size of the ion source for the ITER neutral beam injection (NBI) system, is operational since beginning of 2013. The first experimental campaign was dedicated to a thorough qualification of the test facility and its diagnostic tools at low RF power (80 kW in total, i.e. 20 kW per driver) in volume operation, i.e. operation without cesium, where the negative hydrogen ion production is done in the plasma volume only. This paper reports on the main results of the second and third experimental campaigns, where Cs was inserted in the ion source for an enhancement of the negative ion production by the surface process. The second experimental campaign was done still with low RF power, both for hydrogen and deuterium, with pulse lengths of up to 500 s. The results of this campaign are rather encouraging, especially in hydrogen, where large current densities with respect to the low RF power could be achieved at a ratio of co-extracted electrons to extracted ions of 0.5-0.6 at the relevant source pressure of 0.3 Pa. Similar large extracted ion currents could be achieved also in deuterium, but with larger amounts of co-extracted electrons. The required ratio of co-extracted electrons to extracted ions of one could be achieved only in short pulses. The third experimental campaign aimed then for approaching the required ITER NBI parameters with respect to the ion and electron extracted currents, both for hydrogen and deuterium, by increasing the RF power with short pulses, i.e. beam-on times of up to 10 s and RF-on time up to 20 s. Current densities near the ITER NBI requirements could be achieved in hydrogen at a ratio of co-extracted electrons to extracted ions of 0.5-0.6 at the relevant source pressure of 0.3 Pa. As it was the case for the low RF operation, the required filter field was significantly lower than expected from the experience with the small

Power deposition by neutral beam injected fast ions in field-reversed configurations

International Nuclear Information System (INIS)

Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasawa, Naotaka

2004-01-01

The effects of Coulomb collisions on neutral beam (NB) injected fast ions into field-reversed configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing-down and pitch-angle collisions. The Monte Carlo method is used for the pitch-angle scattering, and the friction term is added to the equation of motion to show the effects of the slowing-down collision, such as the deposited power profile. The calculation parameters used are relevant to the NB injection on the FRC injection experiment device [T. Asai, Y. Suzuki, T. Yoneda, F. Kodera, M. Okubo, and S. Goto, Phys. Plasmas 7, 2294 (2000)]. It is found that the dominant local power deposition occurs in the open field region between the X point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch-angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found to be negligible. The loss mechanism due to nonadiabatic fast ion motion, which is intrinsic in nonuniform FRC plasmas, has a much greater effect than the pitch-angle scattering by Coulomb collision

Impurity behavior during ion-Bernstein wave heating in PBX-M

Science.gov (United States)

Isler, R. C.; Post-Zwicker, A. P.; Paul, S. F.; Tighe, W.; Ono, M.; Leblanc, B. P.; Bell, R.; Kugel, H. W.; Kaita, R.

1994-07-01

Ion-Bernstein-wave heating (IBWH) has been tested in several tokamaks. In some cases the results have been quite positive, producing temperature increases and also improving both energy and particle confinement times, whereas in others, no distinctive changes were observed. Most recently, IBWH has been utilized in the Princeton Beta Experiment-Modified (PBX-M) where the long-range goal is the achievement of operation in the second stable region by current and pressure profile control. Investigations have been performed in this machine using IBWH as the sole source of auxiliary power or using IBWH in conjunction with neutral-beam injection (NBI) or with lower-hybrid current drive (LHCD). Impurity studies seem particularly important for IBWH since not only have influxes often been observed to increase, but the global impurity confinement time has also been shown to lengthen as the confinement of the working gas improved. The authors present here a set of characteristic experimental results regarding the impurity behavior in PBX-M; in general, these are consonant with previous observations in other tokamaks.

Three-dimensional modeling of a negative ion source with a magnetic filter: impact of biasing the plasma electrode on the plasma asymmetry

Science.gov (United States)

Fubiani, G.; Boeuf, J. P.

2015-10-01

The effect on the plasma characteristics of biasing positively the plasma electrode (PE) in negative ion sources with a magnetic filter is analysed using a 3D particle-in-cell model with Monte-Carlo collisions (PIC-MCC). We specialize to the one driver (i.e. one inductively coupled radio-frequency discharge) BATMAN negative ion source and the 4-drivers (large volume) ELISE device. Both are ITER prototype high power tandem-type negative ion sources developed for the neutral beam injector (NBI) system. The plasma is generated in the driver and diffuses inside the second chamber which is magnetized. Asymmetric plasma profiles originate from the formation of an electric field transverse to the electron current flowing through the magnetic filter (Hall effect). The model shows that the importance of the asymmetry increases with the PE bias potential, i.e. with the electron flow from the driver to the extraction region and depends on the shape of the magnetic filter field. We find that although the plasma density and potential profiles may be more or less asymmetric depending on the filter field configuration, the electron current to the plasma grid is always strongly asymmetric.

Three-dimensional modeling of a negative ion source with a magnetic filter: impact of biasing the plasma electrode on the plasma asymmetry

International Nuclear Information System (INIS)

Fubiani, G; Boeuf, J P

2015-01-01

The effect on the plasma characteristics of biasing positively the plasma electrode (PE) in negative ion sources with a magnetic filter is analysed using a 3D particle-in-cell model with Monte-Carlo collisions (PIC-MCC). We specialize to the one driver (i.e. one inductively coupled radio-frequency discharge) BATMAN negative ion source and the 4-drivers (large volume) ELISE device. Both are ITER prototype high power tandem-type negative ion sources developed for the neutral beam injector (NBI) system. The plasma is generated in the driver and diffuses inside the second chamber which is magnetized. Asymmetric plasma profiles originate from the formation of an electric field transverse to the electron current flowing through the magnetic filter (Hall effect). The model shows that the importance of the asymmetry increases with the PE bias potential, i.e. with the electron flow from the driver to the extraction region and depends on the shape of the magnetic filter field. We find that although the plasma density and potential profiles may be more or less asymmetric depending on the filter field configuration, the electron current to the plasma grid is always strongly asymmetric. (paper)

Global MHD modes excited by energetic ions in heliotron/torsatron plasmas

International Nuclear Information System (INIS)

Toi, K.; Takechi, M.; Takagi, S.

1999-01-01

In the CHS heliotron/torsatron, fishbone instabilities (FBs) and toroidal Alfven eigenmodes(TAEs) are observed for the first time, in NBI heated plasmas where small beam driven current is induced. Pulsed increase in energetic ion loss flux is detected by an escaping ion probe during the m=3/n=2 FBs(m,n:poloidal and toroidal mode numbers). The sawtooth crash is often induced by the m=2/n=1 FBs. The current driven internal kink mode and pressure driven interchange modes are thought to be relevant MHD instabilities to FBs. TAEs with n=1 and n=2 are identified, and localized near the plasma core region where fairly low magnetic shear would be realized by the small net plasma current. So far, the observed TAEs do not lead to enhanced loss of energetic ions because of low magnetic fluctuation level. (author)

Global MHD modes excited by energetic ions in heliotron/torsatron plasmas

International Nuclear Information System (INIS)

Toi, K.; Takechi, M.; Takagi, S.

2001-01-01

In the CHS heliotron/torsatron, fishbone instabilities (FBs) and toroidal Alfven eigenmodes (TAEs) are observed for the first time, in NBI heated plasmas where small beam driven current is induced. Pulsed increase in energetic ion loss flux is detected by an escaping ion probe during the m=3/n=2 FBs (m,n: poloidal and toroidal mode numbers). The sawtooth crash is often induced by the m=2/n=1 FBs. The current driven internal kink mode and pressure driven interchange modes are thought to be relevant MHD instabilities to FBs. TAEs with n=1 and n=2 are identified, and localized near the plasma core region where fairly low magnetic shear would be realized by the small net plasma current. So far, the observed TAEs do not lead to enhanced loss of energetic ions because of low magnetic fluctuation level. (author)

Experimental study of ion stopping power in warm dense matter: charge-state distribution measurements of ions leaving warm dense matter

International Nuclear Information System (INIS)

Gauthier, Maxence

2013-01-01

The determination if the ion slowing down process (or stopping power) in warm dense matter is essential especially in the frame of inertial confinement fusion. During my thesis, our interest was driven by the modification of the charge state of ion beam emerging from warm dense matter, this quantity playing a major role in ion stopping power calculation. We took advantage of the properties exhibited by ion beams produced by high intensity short pulse lasers to study during two experiments performed at ELFIE and TITAN facilities, the charge state modification of a carbon and helium ion beams emerging from an aluminum foil isochorically heated by an energetic proton beam. In the first two chapters are presented the major challenges regarding the subject from both a theoretical and experimental point of view. Here are exposed the different simulation tools used during the thesis. The third chapter is devoted to the study of the property of laser-produced ion beams in the scope of our experiments aiming at studying the stopping power. We have studied in particular ion beams generated using lower-than-solid density targets during two experiments: helium gas jet and laser-exploded target. In the last chapter are presented the set-ups and results of the two experiments on the charge state of ion beam emerging from warm dense matter. The data we measured in solid-density cold aluminum are successfully compared with the results already obtained in conventional accelerators. (author) [fr

Influence of RF heating and MHD instabilities on the fast-ion distribution in ASDEX upgrade

Energy Technology Data Exchange (ETDEWEB)

Weiland, Markus

2016-06-07

Fast, supra-thermal ions provide a powerful mechanism to heat fusion plasmas. Through Coulomb collisions with the thermal bulk plasma, they slow down and transfer their energy to the plasma. In present-day devices, fast ions are generated by neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH). In future fusion reactors, the dominant heating source, which allows the ignition of a burning plasma, will be fast a-particles resulting from fusion reactions. In addition to plasma heating, fast ions can be utilized to drive plasma currents and rotation. It is therefore crucial for the success of future fusion devices (such as ITER and DEMO) to understand the physics of fast ions and ensure their safe confinement. This thesis focuses both on modeling and experimental aspects. A model to calculate the NBI fast-ion distribution rapidly has been developed. It is based on a combination of existing codes and analytic solutions. Due to the comparably low numerical effort, it can be used to calculate the fast-ion distribution in a large set of discharges, which is used to e.g. improve plasma equilibrium reconstructions. Experimentally, the physics of fast ions is investigated at the tokamak ASDEX Upgrade, using a FIDA (Fast-Ion D-Alpha) spectroscopy diagnostic. This diagnostic technique is based on charge-exchange reactions, that convert the ions into neutral atoms (keeping their momenta). The light emission from these neutral atoms can be collected by optics in the machine and analyzed with spectrometers. Here, the fast-ion contribution can be identified due to large Doppler shifts, and the shape of the spectrum yields information about the velocity distribution. The Doppler shift is given by a projection of the ion velocity vector onto the line of sight, such that observation from different viewing angles is needed to cover the entire velocity space. Therefore, the FIDA diagnostic has been upgraded from three viewing arrays to five, and the spectrometer has

Influence of RF heating and MHD instabilities on the fast-ion distribution in ASDEX upgrade

International Nuclear Information System (INIS)

Weiland, Markus

2016-01-01

Fast, supra-thermal ions provide a powerful mechanism to heat fusion plasmas. Through Coulomb collisions with the thermal bulk plasma, they slow down and transfer their energy to the plasma. In present-day devices, fast ions are generated by neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH). In future fusion reactors, the dominant heating source, which allows the ignition of a burning plasma, will be fast a-particles resulting from fusion reactions. In addition to plasma heating, fast ions can be utilized to drive plasma currents and rotation. It is therefore crucial for the success of future fusion devices (such as ITER and DEMO) to understand the physics of fast ions and ensure their safe confinement. This thesis focuses both on modeling and experimental aspects. A model to calculate the NBI fast-ion distribution rapidly has been developed. It is based on a combination of existing codes and analytic solutions. Due to the comparably low numerical effort, it can be used to calculate the fast-ion distribution in a large set of discharges, which is used to e.g. improve plasma equilibrium reconstructions. Experimentally, the physics of fast ions is investigated at the tokamak ASDEX Upgrade, using a FIDA (Fast-Ion D-Alpha) spectroscopy diagnostic. This diagnostic technique is based on charge-exchange reactions, that convert the ions into neutral atoms (keeping their momenta). The light emission from these neutral atoms can be collected by optics in the machine and analyzed with spectrometers. Here, the fast-ion contribution can be identified due to large Doppler shifts, and the shape of the spectrum yields information about the velocity distribution. The Doppler shift is given by a projection of the ion velocity vector onto the line of sight, such that observation from different viewing angles is needed to cover the entire velocity space. Therefore, the FIDA diagnostic has been upgraded from three viewing arrays to five, and the spectrometer has

High-confinement NBI discharges in the W7-AS stellarator

International Nuclear Information System (INIS)

Stroth, U.; Baldzuhn, J.; Geiger, J.; Geist, T.; Giannone, L.; Hartfuss, H.-J.; Hirsch, M.; Jaenicke, R.; Kick, M.; Koponen, J.P.; Kuehner, G.; Penningsfeld, F.-P.; Wagner, F.

1998-01-01

In W7-AS, the longest energy confinement times were achieved in neutral beam injection heated (NBI-heated) discharges under low wall-recycling conditions. Low recycling is needed to control the density at line-averaged values of n-bar e approx. 10 20 m -3 . Under these conditions, confinement was improved by a factor of two above the common scaling estimate. The reduction of radial transport is concentrated into a layer at about two-thirds of the plasma radius. In this region steep pressure gradients and a strong gradient in the radial electric field develop. Specific for the discharges is the slow transition to improved confinement, lasting up to three energy confinement times. Since the measured electric field is consistent with the neoclassical ambipolar field, this high-confinement mode could be an example where sheared plasma flow as created by the neoclassical radial electric field leads to a suppression of anomalous transport. (author)

High-confinement NBI discharges in the W7-AS stellarator

Energy Technology Data Exchange (ETDEWEB)

Stroth, U; Baldzuhn, J; Geiger, J; Geist, T; Giannone, L.; Hartfuss, H -J; Hirsch, M; Jaenicke, R; Kick, M; Koponen, J P; Kuehner, G; Penningsfeld, F -P; Wagner, F [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

1998-08-01

In W7-AS, the longest energy confinement times were achieved in neutral beam injection heated (NBI-heated) discharges under low wall-recycling conditions. Low recycling is needed to control the density at line-averaged values of n-bar{sub e} approx. 10{sup 20}m{sup -3}. Under these conditions, confinement was improved by a factor of two above the common scaling estimate. The reduction of radial transport is concentrated into a layer at about two-thirds of the plasma radius. In this region steep pressure gradients and a strong gradient in the radial electric field develop. Specific for the discharges is the slow transition to improved confinement, lasting up to three energy confinement times. Since the measured electric field is consistent with the neoclassical ambipolar field, this high-confinement mode could be an example where sheared plasma flow as created by the neoclassical radial electric field leads to a suppression of anomalous transport. (author)

Research results for the applications of high power ion beams

International Nuclear Information System (INIS)

Yang Hailiang; Qiu Aici; Sun Jianfeng; He Xiaoping; Tang Junping; Wang Haiyang; Zhang Jiasheng; Xu Ri; Peng Jianchang; Ren Shuqing; Li Peng; Yang Li; Huang Jianjun; Zhang Guoguang; Ouyang Xiaoping; Li Hongyu

2003-01-01

The results obtained in the theoretical and experimental studies for the application of high power ion beams in certain areas of nuclear physics and material science are reported. The preliminary experimental results of generating 6-7 MeV quasi-monoenergetic pulsed γ-rays with high power pulsed proton beams striking 19 F target on the Flash II accelerator are presented. By placing the target far enough downstream, the quasi-monoenergetic pulsed γ-rays can be discriminated experimentally from the diode Bremsstrahlung. This article also describes the other applications of high power ion beams and the preliminary experimental and theoretical results in simulation of soft X-ray thermal-mechanical effects, generation of high intense pulsed neutrons, equation of state and shock-wave physics experiments, surface modification and so on

Confinement properties of JET plasmas with different temperature and density profiles

International Nuclear Information System (INIS)

Watkins, M.L.; Balet, B.; Bhatnagar, V.P.

1989-01-01

The confinement properties of plasmas with substantially different temperature and density profiles have been analysed. The effects of fast particles and energy pedestals on the overall confinement of plasma energy in limiter (L-mode) and X-point (L- and H-modes) discharges heated by NBI or ICRF or both are determined. The importance of the bootstrap current when such energy pedestals are formed is noted. Using sets of consistent experimental data, including ion temperature profile measurements, the local transport properties are compared in the L- and H-phases of a single null X-point medium density NBI heated discharge, the ''enhanced'' confinement phase of a limiter high density pellet-fuelled and ICRF heated discharge, the hot-ion phase of a double null X-point low density NBI heated discharge and the hot-ion and H-phases of a double null X-point low density high temperature NBI heated discharge. (author)

Lithium Ion Battery Chemistries from Renewable Energy Storage to Automotive and Back-up Power Applications

DEFF Research Database (Denmark)

Stan, Ana-Irina; Swierczynski, Maciej Jozef; Stroe, Daniel Ioan

2014-01-01

Lithium ion (Li-ion) batteries have been extensively used in consumer electronics because of their characteristics, such as high efficiency, long life, and high gravimetric and volumetric energy. In addition, Li-ion batteries are becoming the most attractive candidate as electrochemical storage...... systems for stationary applications, as well as power source for sustainable automotive and back-up power supply applications. This paper gives an overview of the Li-ion battery chemistries that are available at present in the market, and describes the three out of four main applications (except...... the consumers’ applications), grid support, automotive, and back-up power, for which the Li-ion batteries are suitable. Each of these applications has its own specifications and thus, the chemistry of the Li-ion battery should be chosen to fulfil the requirements of the corresponding application. Consequently...

Analysis and Interpretation of the Plasma Dynamic Response to Additional Heating Power using different Diagnostics

International Nuclear Information System (INIS)

Manini, A.

2002-07-01

The main goal in the research of nuclear fusion, and therefore in tokamak research as well, is the development of a high power, steady-state power plant. To obtain the high power required for igniting the plasma, the size of the device must be very large. The performance of the tokamak plasma depends in particular on the plasma shape and on the internal plasma profiles. These profiles include those of the current density and the pressure, two quantities that can be modified by means of auxiliary heating methods such as Electron Cyclotron Heating (ECH). ECH is a very important tool due to its capability of injecting highly localised and intense power. Off-axis ECH and Electron Cyclotron Current Drive (ECCD) modify both current density and electron temperature profiles, leading to modification of confinement and stability properties. in particular, complete stabilisation of magnetohydrodynamic modes using ECCD is feasible. Furthermore, ECH is crucial as a mean of increasing the bootstrap current fraction through the formation of internal transport barriers, so that confinement is also improved. Finally, it is also noted that modulated ECH (MECH) is a very effective tool for perturbative energy transport experiments in many different regimes. Experiments performed in the TCV and the ASDEX Upgrade tokamaks are presented. The role of TCV is very important due to its flexibility of varying the plasma shape, its versatile high power ECH system at both the second and third electron cyclotron harmonics, and due to the numerous diagnostics installed, e.g. the two soft X-ray (SXR) diagnostics which simultaneously allow high temporal and spatial resolutions. The importance of ASDEX Upgrade is related to its large size, which makes it a reactor-relevant experimental facility, and to the Neutral Beam Injection (NBI) and ECH heating facilities, which allow a study of heat and particle transport in either mostly ion-heated or mostly electron-heated regimes. Moreover, for the

Ultracompact/ultralow power electron cyclotron resonance ion source for multipurpose applications

International Nuclear Information System (INIS)

Sortais, P.; Lamy, T.; Medard, J.; Angot, J.; Latrasse, L.; Thuillier, T.

2010-01-01

In order to drastically reduce the power consumption of a microwave ion source, we have studied some specific discharge cavity geometries in order to reduce the operating point below 1 W of microwave power (at 2.45 GHz). We show that it is possible to drive an electron cyclotron resonance ion source with a transmitter technology similar to those used for cellular phones. By the reduction in the size and of the required microwave power, we have developed a new type of ultralow cost ion sources. This microwave discharge system (called COMIC, for COmpact MIcrowave and Coaxial) can be used as a source of light, plasma or ions. We will show geometries of conductive cavities where it is possible, in a 20 mm diameter chamber, to reduce the ignition of the plasma below 100 mW and define typical operating points around 5 W. Inside a simple vacuum chamber it is easy to place the source and its extraction system anywhere and fully under vacuum. In that case, current densities from 0.1 to 10 mA/cm 2 (Ar, extraction 4 mm, 1 mAe, 20 kV) have been observed. Preliminary measurements and calculations show the possibility, with a two electrodes system, to extract beams within a low emittance. The first application for these ion sources is the ion injection for charge breeding, surface analyzing system and surface treatment. For this purpose, a very small extraction hole is used (typically 3/10 mm for a 3 μA extracted current with 2 W of HF power). Mass spectrum and emittance measurements will be presented. In these conditions, values down to 1 π mm mrad at 15 kV (1σ) are observed, thus very close to the ones currently observed for a surface ionization source. A major interest of this approach is the possibility to connect together several COMIC devices. We will introduce some new on-going developments such as sources for high voltage implantation platforms, fully quartz radioactive ion source at ISOLDE or large plasma generators for plasma immersion, broad or ribbon beams

Ultracompact/ultralow power electron cyclotron resonance ion source for multipurpose applications

Energy Technology Data Exchange (ETDEWEB)

Sortais, P.; Lamy, T.; Medard, J.; Angot, J.; Latrasse, L.; Thuillier, T. [Laboratoire de Physique Subatomique et de Cosmologie de Grenoble, UJF-CNRS/IN2P3 - INPG, 53, rue des Martyrs, 38026 Grenoble Cedex (France)

2010-02-15

In order to drastically reduce the power consumption of a microwave ion source, we have studied some specific discharge cavity geometries in order to reduce the operating point below 1 W of microwave power (at 2.45 GHz). We show that it is possible to drive an electron cyclotron resonance ion source with a transmitter technology similar to those used for cellular phones. By the reduction in the size and of the required microwave power, we have developed a new type of ultralow cost ion sources. This microwave discharge system (called COMIC, for COmpact MIcrowave and Coaxial) can be used as a source of light, plasma or ions. We will show geometries of conductive cavities where it is possible, in a 20 mm diameter chamber, to reduce the ignition of the plasma below 100 mW and define typical operating points around 5 W. Inside a simple vacuum chamber it is easy to place the source and its extraction system anywhere and fully under vacuum. In that case, current densities from 0.1 to 10 mA/cm{sup 2} (Ar, extraction 4 mm, 1 mAe, 20 kV) have been observed. Preliminary measurements and calculations show the possibility, with a two electrodes system, to extract beams within a low emittance. The first application for these ion sources is the ion injection for charge breeding, surface analyzing system and surface treatment. For this purpose, a very small extraction hole is used (typically 3/10 mm for a 3 {mu}A extracted current with 2 W of HF power). Mass spectrum and emittance measurements will be presented. In these conditions, values down to 1 {pi} mm mrad at 15 kV (1{sigma}) are observed, thus very close to the ones currently observed for a surface ionization source. A major interest of this approach is the possibility to connect together several COMIC devices. We will introduce some new on-going developments such as sources for high voltage implantation platforms, fully quartz radioactive ion source at ISOLDE or large plasma generators for plasma immersion, broad or ribbon

Heavy-ion-induced, gate-rupture in power MOSFETs

International Nuclear Information System (INIS)

Fischer, T.A.

1987-01-01

A new, heavy-ion-induced, burnout mechanism has been experimentally observed in power metal-oxide-semiconductor field-effect transistors (MOSFETs). This mechanism occurs when a heavy, charged particle passes through the gate oxide region of n- or p-channel devices having sufficient gate-to-source or gate-to-drain bias. The gate-rupture leads to significant permanent degradation of the device. A proposed failure mechanism is discussed and experimentally verified. In addition, the absolute immunity of p-channel devices to heavy-ion-induced, semiconductor burnout is demonstrated and discussed along with new, non-destructive, burnout testing methods

Towards a realistic 3D simulation of the extraction region in ITER NBI relevant ion source

Science.gov (United States)

Mochalskyy, S.; Wünderlich, D.; Fantz, U.; Franzen, P.; Minea, T.

2015-03-01

The development of negative ion (NI) sources for ITER is strongly accompanied by modelling activities. The ONIX code addresses the physics of formation and extraction of negative hydrogen ions at caesiated sources as well as the amount of co-extracted electrons. In order to be closer to the experimental conditions the code has been improved. It includes now the bias potential applied to first grid (plasma grid) of the extraction system, and the presence of Cs+ ions in the plasma. The simulation results show that such aspects play an important role for the formation of an ion-ion plasma in the boundary region by reducing the depth of the negative potential well in vicinity to the plasma grid that limits the extraction of the NIs produced at the Cs covered plasma grid surface. The influence of the initial temperature of the surface produced NI and its emission rate on the NI density in the bulk plasma that in turn affects the beam formation region was analysed. The formation of the plasma meniscus, the boundary between the plasma and the beam, was investigated for the extraction potentials of 5 and 10 kV. At the smaller extraction potential the meniscus moves closer to the plasma grid but as in the case of 10 kV the deepest meniscus bend point is still outside of the aperture. Finally, a plasma containing the same amount of NI and electrons (nH- =ne =1017 m-3) , representing good source conditioning, was simulated. It is shown that at such conditions the extracted NI current can reach values of ˜32 mA cm-2 using ITER-relevant extraction potential of 10 kV and ˜19 mA cm-2 at 5 kV. These results are in good agreement with experimental measurements performed at the small scale ITER prototype source at the test facility BATMAN.

Flexible Aqueous Li-Ion Battery with High Energy and Power Densities.

Science.gov (United States)

Yang, Chongyin; Ji, Xiao; Fan, Xiulin; Gao, Tao; Suo, Liumin; Wang, Fei; Sun, Wei; Chen, Ji; Chen, Long; Han, Fudong; Miao, Ling; Xu, Kang; Gerasopoulos, Konstantinos; Wang, Chunsheng

2017-11-01

A flexible and wearable aqueous symmetrical lithium-ion battery is developed using a single LiVPO 4 F material as both cathode and anode in a "water-in-salt" gel polymer electrolyte. The symmetric lithium-ion chemistry exhibits high energy and power density and long cycle life, due to the formation of a robust solid electrolyte interphase consisting of Li 2 CO 3 -LiF, which enables fast Li-ion transport. Energy densities of 141 Wh kg -1 , power densities of 20 600 W kg -1 , and output voltage of 2.4 V can be delivered during >4000 cycles, which is far superior to reported aqueous energy storage devices at the same power level. Moreover, the full cell shows unprecedented tolerance to mechanical stress such as bending and cutting, where it not only does not catastrophically fail, as most nonaqueous cells would, but also maintains cell performance and continues to operate in ambient environment, a unique feature apparently derived from the high stability of the "water-in-salt" gel polymer electrolyte. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experiments on high-power ion beam generation in self-insulated diodes

International Nuclear Information System (INIS)

Bystritskii, V.M.; Glyshko, Yu.A.; Sinerbrjukhov, A.A.; Kharlov, A.V.

1991-01-01

Experimental results are given on high-power ion beams (HPIB) generation in a vacuum spherical focusing diode with self-magnetic insulation, obtained from the nanosecond accelerator PARUS with 0.2-TW power and 60-ns pulse duration for a matched load. When the passive plasma source of the ions was used, the efficiency of the HPIB generation was measured to be as high as 20% for 700-kV diode voltage and 10-kA/cm 2 beam density in the focal plane. The application of a coaxial plasma opening switch (POS) prior to the diode resulted in a factor-of-1.8 increase in the diode power in comparison with a match operation in the absence of a POS. (author)

Development of KSTAR Neutral Beam Heating System

Energy Technology Data Exchange (ETDEWEB)

Oh, B. H.; Song, W. S.; Yoon, B. J. (and others)

2007-10-15

The prototype components of a neutral beam injection (NBI) system have been developed for the KSTAR, and a capability of the manufactured components has been tested. High power ion source, acceleration power supply, other ion source power supplies, neutralizer, bending magnet for ion beam separation, calorimeter, and cryo-sorption pump have been developed by using the domestic technologies and tested for a neutral beam injection of 8 MW per beamline with a pulse duration of 300 seconds. The developed components have been continuously upgraded to achieve the design requirements. The development technology of high power and long pulse neutral beam injection system has been proved with the achievement of 5.2 MW output for a short pulse length and 1.6 MW output for a pulse length of 300 seconds. Using these development technologies, the domestic NB technology has been stabilized under the development of high power ion source, NB beamline components, high voltage and current power supplies, NB diagnostics, NB system operation and control.

Apparatus and method for extracting power from energetic ions produced in nuclear fusion

Science.gov (United States)

Fisch, Nathaniel J.; Rax, Jean M.

1994-01-01

An apparatus and method of extracting power from energetic ions produced by nuclear fusion in a toroidal plasma to enhance respectively the toroidal plasma current and fusion reactivity. By injecting waves of predetermined frequency and phase traveling substantially in a selected poloidal direction within the plasma, the energetic ions become diffused in energy and space such that the energetic ions lose energy and amplify the waves. The amplified waves are further adapted to travel substantially in a selected toroidal direction to increase preferentially the energy of electrons traveling in one toroidal direction which, in turn, enhances or generates a toroidal plasma current. In an further adaptation, the amplified waves can be made to preferentially increase the energy of fuel ions within the plasma to enhance the fusion reactivity of the fuel ions. The described direct, or in situ, conversion of the energetic ion energy provides an efficient and economical means of delivering power to a fusion reactor.

Stopping Power and Energy Straggling of Channeled He-Ions in GaN

International Nuclear Information System (INIS)

Turos, A.; Ratajczak, R.; Pagowska, K.; Nowicki, L.; Stonert, A.; Caban, P.

2011-01-01

GaN epitaxial layers are usually grown on sapphire substrates. To avoid disastrous effect of the large lattice mismatch a thin polycrystalline nucleation layer is grown at 500 o C followed by the deposition of thick GaN template at much higher temperature. Remnants of the nucleation layer were visualized by transmission electron microscopy as defect agglomeration at the GaN/sapphire interface and provide a very useful depth marker for the measurement of channeled ions stopping power. Random and aligned spectra of He ions incident at energies ranging from 1.7 to 3.7 MeV have been measured and evaluated using the Monte Carlo simulation code McChasy. Impact parameter dependent stopping power has been calculated for channeling direction and its parameters have been adjusted according to experimental data. For virgin, i.e. as grown, samples, the ratio of channeled to random stopping power is constant and amounts to 0.7 in the energy range studied. Defects produced by ion implantation largely influence the stopping power. For channeled ions the variety of possible trajectories leads to different energy loss at a given depth, thus resulting in much larger energy straggling than that for the random path. Beam energy distributions at different depths have been calculated using the McChasy code. They are significantly broader than those predicted by the Bohr formula for random direction. (author)

A study on the NB heating and current drive in fusion plasmas

International Nuclear Information System (INIS)

Jeong, Seung Ho; In, S. R.; Lee, K. W.; Oh, B. H.; Jin, J. T.; Chang, D. H.; Chang, D. S.; Kim, T. S.; Song, W. S.

2013-03-01

Final destination of the project is to establish the research basis of heating and current drive for large tokamak, such as KSTAR, or next generation fusion reactor through the neutral beam injection (NBI). On the 1 st -stage to achieve the objectives: 1) Required capability of an ion source(with an output power of 2 MW neutral beam, a beam energy of 100 keV) which is a main component of KSTAR NBI-1 system was proven by the design, manufacturing, and performance test during the past three years. 2) Until the development of new ion source, the NB heating experiments were performed to achieve the NB heating of KSTAR plasma with more than 1.0 MW for the 2 nd -year and more than 1.5 MW for the 3 rd -year by using a prototype ion source upgraded for the 1 st -year. From these experiments, the heating power above the H-mode threshold was supplied to the H-mode operation of KSTAR plasma and contributed to the NB diagnostics, such as CES and MSE, by using the NB. Finally, the basis of NB heating and current drive for the KSTAR was prepared by the 1 st -stage research

Physics of high performance deuterium-tritium plasmas in TFTR

International Nuclear Information System (INIS)

McGuire, K.M.; Batha, S.

1996-11-01

During the past two years, deuterium-tritium (D-T) plasmas in the Tokamak Fusion Test Reactor (TFTR) have been used to study fusion power production, isotope effects associated with tritium fueling, and alpha-particle physics in several operational regimes. The peak fusion power has been increased to 10.7 MW in the supershot mode through the use of increased plasma current and toroidal magnetic field and extensive lithium wall conditioning. The high-internal-inductance (high-I i ) regime in TFTR has been extended in plasma current and has achieved 8.7 MW of fusion power. Studies of the effects of tritium on confinement have now been carried out in ohmic, NBI- and ICRF- heated L-mode and reversed-shear plasmas. In general, there is an enhancement in confinement time in D-T plasmas which is most pronounced in supershot and high-I i discharges, weaker in L-mode plasmas with NBI and ICRF heating and smaller still in ohmic plasmas. In reversed-shear discharges with sufficient deuterium-NBI heating power, internal transport barriers have been observed to form, leading to enhanced confinement. Large decreases in the ion heat conductivity and particle transport are inferred within the transport barrier. It appears that higher heating power is required to trigger the formation of a transport barrier with D-T NBI and the isotope effect on energy confinement is nearly absent in these enhanced reverse-shear plasmas. Many alpha-particle physics issues have been studied in the various operating regimes including confinement of the alpha particles, their redistribution by sawteeth, and their loss due to MHD instabilities with low toroidal mode numbers. In weak-shear plasmas, alpha-particle destabilization of a toroidal Alfven eigenmode has been observed

Preliminary research results for the generation and diagnostics of high power ion beams on FLASH II accelerator

International Nuclear Information System (INIS)

Yang Hailiang; Qiu Aici; Sun Jianfeng; He Xiaoping; Tang Junping; Wang Haiyang; Li Jingya; Ren Shuqing; Ouyang Xiaoping; Zhang Guoguang; Li Hongyu

2004-01-01

The preliminary experimental results of the generation and diagnostics of high-power ion beams on FLASH II accelerator are reported. The high-power ion beams presently are being produced in a pinched diode. The method for enhancing the ratio of ion to electron current is to increase the electron residing time by pinching the electron flow. Furthermore, electron beam pinching can be combined with electron reflexing to achieve ion beams with even higher efficiency and intensity. The anode plasma is generated by anode foil bombarded with electron and anode foil surface flashover. In recent experiments on FLASH II accelerator, ion beams have been produced with a current of 160 kA and an energy of 500 keV corresponding to an ion beam peak power of about 80 GW. The ion number and current of high power ion beams were determined by monitoring delayed radioactivity from nuclear reactions induced in a 12 C target by the proton beams. The prompt γ-rays and diode Bremsstrahlung X-rays were measured with a PIN semi-conductor detector and a plastic scintillator detector. The current density distribution of ion beam was measured with a biased ion collector array. The ion beams were also recorded with a CR-39 detector. (authors)

Lifetime and economic analyses of lithium-ion batteries for balancing wind power forecast error

DEFF Research Database (Denmark)

Swierczynski, Maciej Jozef; Stroe, Daniel Ioan; Stroe, Ana-Irina

2015-01-01

is considered. In this paper, the economic feasibility of lithium-ion batteries for balancing the wind power forecast error is analysed. In order to perform a reliable assessment, an ageing model of lithium-ion battery was developed considering both cycling and calendar life. The economic analysis considers two......, it was found that for total elimination of the wind power forecast error, it is required to have a 25-MWh Li-ion battery energy storage system for the considered 2 MW WT....

Control system for 5 MW neutral beam ion source for SST1

Science.gov (United States)

Patel, G. B.; Onali, Raja; Sharma, Vivek; Suresh, S.; Tripathi, V.; Bandyopadhyay, M.; Singh, N. P.; Thakkar, Dipal; Gupta, L. N.; Singh, M. J.; Patel, P. J.; Chakraborty, A. K.; Baruah, U. K.; Mattoo, S. K.

2006-01-01

This article describes the control system for a 5MW ion source of the NBI (neutral beam injector) for steady-state superconducting tokamak-1 (SST-1). The system uses both hardware and software solutions. It comprises a DAS (data acquisition system) and a control system. The DAS is used to read the voltage and current signals from eight filament heater power supplies and 24 discharge power supplies. The control system is used to adjust the filament heater current in order to achieve an effective control on the discharge current in the plasma box. The system consists of a VME (Verse Module Eurocard) system and C application program running on a VxWorks™ real-time operating system. A PID (proportional, integral, and differential) algorithm is used to control the filament heater current. Experiments using this system have shown that the discharge current can be controlled within 1% accuracy for a PID loop time of 20ms. Response of the control system to the pressure variation of the gas in the chamber has also been studied and compared with the results obtained from those of an uncontrolled system. The present approach increases the flexibility of the control system. It not only eases the control of the plasma but also allows an easy changeover to various operation scenarios.

Lithium ion battery energy storage system for augmented wind power plants

DEFF Research Database (Denmark)

Swierczynski, Maciej Jozef

with Battery Energy Storage Systems (BESSs) into the so called Virtual Power Plants (VPP). Relatively new energy storage technologies based on Lithium ion (Li-ion) batteries are constantly improving their performance and are becoming attractive for stationary energy storage applications due...... to their characteristics such as high power, high efficiency, low self-discharge, and long lifetime. The family of the Li-ion batteries is wide and the selection of the most appropriate Liion chemistries for VPPs is one of the topics of this thesis, where different chemistries are compared and the most suitable ones...... if the batteries are able to meet several performance requirements, which are application dependent. Furthermore, for the VPP, the degradation or failure of the interconnected BESS can lead to costly downtime. Thus, an accurate estimation of the battery cells lifetime becomes mandatory. However, lifetime...

Characteristics of the low power cylindrical anode layer ion source

International Nuclear Information System (INIS)

Zhao Jie; Tang Deli; Cheng Changming; Geng Shaofei

2009-01-01

A low power cylindrical anode layer ion source and its working characteristic, and the beam distribution are introduced. This ion source has two working states, emanative state and collimated state, and the normal parameters of this system are: working voltage 200-1200 V, discharge current 0.1-1.4A, air pressure 1.9 x 10 -2 -1.7 x 10 -1 Pa, gas flow 5-20 sccm. (authors)

A series of coordination polymers constructed from R-isophthalic acid (R=-SO3H, -NO2, and -OH) and N-donor ligands: Syntheses, structures and fluorescence properties

Science.gov (United States)

Zhou, Yong-Hong; Zhou, Xu-Wan; Zhou, Su-Rong; Tian, Yu-Peng; Wu, Jie-Ying

2017-01-01

Six novel Zn(II), Cd(II), and Cu(II) mixed-ligand coordination complexes, namely, [Zn2Na(sip)2(bpp)3(Hbpp)(H2O)2]·8H2O (1), [Cd3(sip)2(nbi)6(H2O)2]·7H2O (2), [Zn(sip)(nbi)2(H2O)]·Hnbi·3H2O (3), [Cd(hip)(nbi)2(H2O)]·nbi·5H2O (4), [Cd2(nip)2(nbi)2(H2O)2]·DMF (5), and [Cu(nip)(nbi)(H2O)2]·H2O (6) (H3sip=5-sulfoisophthalic acid, H2hip=5-hydroxylisophthalic acid, H2nip=5-nitroisophthalic acid, bpp=1,3-bis(4-pyridyl)propane, and nbi=6-nitrobenzimidazole) have been synthesized hydrothermally by the self-assembly of R-isophthalic acid (R=-SO3H, -NO2, and -OH) and N-donor ligands. Single crystal X-ray analyses reveal that two Zn(II) ions and one Na(I) ion of complex 1 are linked through O atoms to generate a 1D linear chain. Then the 2D supramolecular architectures are constructed via intermolecular interactions. In complex 2, the Cd1 ions are connected by bridging carboxyl groups from sip3- anions to form 1D double chain, which are further connected by Cd2 ions to afford 2D layer structure. The adjacent 2D layers are further linked via hydrogen-bonding interactions to give 3D supramolecular network. Compounds 3-5 show 1D chain structures, which are assembled into 2D or 3D supramolecular frameworks via weak interactions. In compound 6, the Cu(II) ions are bridged by the nip2- ligands to form 48-membered ring, which is assembled into 1Dchain via the π-π stacking interaction. In addition, the thermal stabilities and fluorescence properties of these compounds have also been studied.

Stopping power for heavy ions in gases: a comparative study

International Nuclear Information System (INIS)

Diwan, P.K.; Singh, Lakhwant; Singh, Gurinder; Shyam Kumar

1999-01-01

The accurate knowledge of stopping power for heavy ions in gases is of paramount importance in nuclear reaction studies for the identification of reaction products involving ΔE-E telescope detectors. In the present work, it has been calculated the stopping power values for different heavy ions, such as Ne, Ar, Cu, Kr and Ag in various gas absorbers like H 2 , He, N 2 , Ne, Ar, Kr and Xe in the energy domain ∼ 2.5-6 MeV/n using the SRIM-98 code recently developed by Ziegler and the formulations of Benton and Henke, Hubert et al, Mukherjee and Nayak and Northcliffe and Schilling. This study has been undertaken in order to establish the validity of various semiempirical formulations for gas targets

Fast-ion losses induced by ELMs and externally applied magnetic perturbations in the ASDEX Upgrade tokamak

International Nuclear Information System (INIS)

Garcia-Munoz, M; Rodriguez-Ramos, M; Äkäslompolo, S; De Marne, P; Dunne, M G; Dux, R; Fietz, S; Fuchs, C; Geiger, B; Herrmann, A; Hoelzl, M; Kurzan, B; McDermott, R M; Strumberger, E; Evans, T E; Ferraro, N M; Pace, D C; Lazanyi, N; Nocente, M; Shinohara, K

2013-01-01

Phase-space time-resolved measurements of fast-ion losses induced by edge localized modes (ELMs) and ELM mitigation coils have been obtained in the ASDEX Upgrade tokamak by means of multiple fast-ion loss detectors (FILDs). Filament-like bursts of fast-ion losses are measured during ELMs by several FILDs at different toroidal and poloidal positions. Externally applied magnetic perturbations (MPs) have little effect on plasma profiles, including fast-ions, in high collisionality plasmas with mitigated ELMs. A strong impact on plasma density, rotation and fast-ions is observed, however, in low density/collisionality and q 95 plasmas with externally applied MPs. During the mitigation/suppression of type-I ELMs by externally applied MPs, the large fast-ion bursts observed during ELMs are replaced by a steady loss of fast-ions with a broad-band frequency and an amplitude of up to an order of magnitude higher than the neutral beam injection (NBI) prompt loss signal without MPs. Multiple FILD measurements at different positions, indicate that the fast-ion losses due to static 3D fields are localized on certain parts of the first wall rather than being toroidally/poloidally homogeneously distributed. Measured fast-ion losses show a broad energy and pitch-angle range and are typically on banana orbits that explore the entire pedestal/scrape-off-layer (SOL). Infra-red measurements are used to estimate the heat load associated with the MP-induced fast-ion losses. The heat load on the FILD detector head and surrounding wall can be up to six times higher with MPs than without 3D fields. When 3D fields are applied and density pump-out is observed, an enhancement of the fast-ion content in the plasma is typically measured by fast-ion D-alpha (FIDA) spectroscopy. The lower density during the MP phase also leads to a deeper beam deposition with an inward radial displacement of ≈2 cm in the maximum of the beam emission. Orbit simulations are used to test different models for 3D

Evaluation of thermal stress in the anode chamber wall of a large volume magnetic bucket ion source

International Nuclear Information System (INIS)

Wells, Russell; Horiike, Hiroshi; Kuriyama, Masaaki; Ohara, Yoshihiro

1984-02-01

Thermal stress analysis was performed on the plasma chamber of the Large Volume Magnetic Multipole Bucket Ion Source (LVB) designed for use on the JT-60 NBI system. The energy absorbed by the walls of the plasma chambers of neutral beam injectors is of the order of 1% of the accelerator electrical drain power. A previous study indicates that a moderately high heat flux, of about 600W/cm 2 , is concentrated on the magnetic field cusp lines during normal full power operation. Abnormal arc discharges during conditioning of a stainless steel LVB produced localized melting of the stainless steel at several locations near the cusps lines. The power contained in abnormal arc discharges (arc spots) was estimated from the observed melting. Thermal stress analysis was performed numerically on representative sections of the copper LVB design for both stable and abnormal arc discharge conditions. Results show that this chamber should not fail due to thermal fatigue stesses arising from normal arc discharges. However, fatigue failure may occur after several hundred to a few thousand arc spots of 30mS duration at any one location. Limited arc discharge operation of the copper bucket was performed to partially verify the chamber's durability. (author)

Secondary electrons as probe of preequilibrium stopping power of ions penetrating solids

International Nuclear Information System (INIS)

Kroneberger, K.; Rothard, H.; Koschar, P.; Lorenzen, P.; Groeneveld, K.O.; Clouvas, A.; Veje, E.; Kemmler, J.

1990-01-01

The passage of ions through solid media is accompanied by the emission of low energy secondary electrons. At high ion velocities v p (i.e. v p > 10 7 cm/s) the kinetic emission of electrons as a result of direct Coulomb interaction between the ion and the target electron is the dominant initial production mechanism. The energy lost by the ion and, thus, transferred to the electrons is known as electronic stopping power in the solid. Elastic and inelastic interactions of primary, liberated electrons on their way through the bulk and the surface of the solid modify strongly their original energy and angular distribution and, in particular, leads to the transfer of their energy to further, i.e. secondary electrons (SE), such that the main part of the deposited energy of the ion is eventually over transferred to SE. It is, therefore, suggestive to assume a proportionality between the electronic stopping power S sm-bullet of the ion and the total SE yield g, i.e. the number of electrons ejected per ion. Following Sternglass the authors consider schematically for kinetic SE emission contributions from two extreme cases: (a) SEs produced mostly isotropically with large impact parameter, associated with an escape depth L SE from the solid; (b) SEs produced mostly unisotropically in forward direction with small impact parameter (δ-electrons), associated with a transport length L δ

Selection and impedance based model of a lithium ion battery technology for integration with virtual power plant

DEFF Research Database (Denmark)

Swierczynski, Maciej Jozef; Stroe, Daniel Ioan; Stan, Ana-Irina

2013-01-01

is to integrate lithium-ion batteries into virtual power plants; thus, the power system stability and the energy quality can be increased. The selection of the best lithium-ion battery candidate for integration with wind power plants is a key aspect for the economic feasibility of the virtual power plant...... investment. This paper presents a methodology for selection, between three candidates, of a Li-ion battery which offers long cycle lifetime at partial charge/discharge (required by many grid support applications) while providing a low cost per cycle also. For the selected Li-ion battery an impedance......-based diagnostic tool for lifetime estimation was developed and verified. This diagnostic tool can be extended into an impedance-based lifetime model that will be able to predict the remaining useful lifetime of Li-ion batteries for specific grid support applications....

Self-consistent calculation of the effects of RF injection in the HHFW heating regimes on the evolution of fast ions in toroidal plasmas

Directory of Open Access Journals (Sweden)

Bertelli Nicola

2017-01-01

Full Text Available A critical question for the use of ion cyclotron range of frequency (ICRF heating in the ITER device and beyond is interaction of fast waves with energetic ion populations from neutral beam injection (NBI, fusion reactions, and minority ions accelerated by the RF waves themselves. Several experiments have demonstrated that the interaction between fast waves and fast ions can indeed be strong enough to significantly modify the NB ion population. To model the RF/fast ion interaction and the resulting fast ion distribution, a recent extension of the full wave solver TORIC v.5 that includes non-Maxwellian effects has been combined with the Monte Carlo NUBEAM code through an RF “kick” operator. In this work, we present an initial verification of the NUBEAM RF “kick” operator for high harmonic fast wave (HHFW heating regime in NSTX plasma.

Conceptual design of a demonstration reactor for electric power generation

International Nuclear Information System (INIS)

Asaoka, Y.; Hiwatari, R.; Okano, K.; Ogawa, Y.; Ise, H.; Nomoto, Y.; Kuroda, T.; Mori, S.; Shinya, K.

2005-01-01

Conceptual study on a demonstration plant for electric power generation, named Demo-CREST, was conducted based on the consideration that a demo-plant should have capacities both (1) to demonstrate electric power generation in a plant scale with moderate plasma performance, which will be achieved in the early stage of the ITER operation, and foreseeable technologies and materials and (2) to have a possibility to show an economical competitiveness with advanced plasma performance and high performance blanket systems. The plasma core was optimized to be a minimum size for both net electric power generation with the ITER basic plasma parameters and commercial-scale generation with advance plasma parameters, which would be attained by the end of ITER operation. The engineering concept, especially the breeding blanket structure and its maintenance scheme, is also optimized to demonstrate the tritium self-sustainability and maintainability of in-vessel components. Within the plasma performance as planned in the present ITER program, the net electric power from 0 MW to 500 MW is possible with the basic blanket system under the engineering conditions of maximum magnetic field 16 T, NBI system efficiency 50%, and NBI current drive power restricted to 200 MW. Capacities of stabilization of reversed shear plasma and the high thermal efficiency are additional factors for optimization of the advanced blanket. By replacing the blanket system with the advanced one of higher thermal efficiency, the net electric power of about 1000 MW is also possible so that the economic performance toward the commercial plant can be also examined with Demo-CREST. (author)

Ion energy loss at maximum stopping power in a laser-generated plasma

International Nuclear Information System (INIS)

Cayzac, W.

2013-01-01

In the frame of this thesis, a new experimental setup for the measurement of the energy loss of carbon ions at maximum stopping power in a hot laser-generated plasma has been developed and successfully tested. In this parameter range where the projectile velocity is of the same order of magnitude as the thermal velocity of the plasma free electrons, large uncertainties of up to 50% are present in the stopping-power description. To date, no experimental data are available to perform a theory benchmarking. Testing the different stopping theories is yet essential for inertial confinement fusion and in particular for the understanding of the alpha-particle heating of the thermonuclear fuel. Here, for the first time, precise measurements were carried out in a reproducible and entirely characterized beam-plasma configuration. It involved a nearly fully-stripped ion beam probing a homogeneous fully-ionized plasma. This plasma was generated by irradiating a thin carbon foil with two high-energy laser beams and features a maximum electron temperature of 200 eV. The plasma conditions were simulated with a two-dimensional radiative hydrodynamic code, while the ion-beam charge-state distribution was predicted by means of a Monte-Carlo code describing the charge-exchange processes of projectile ions in plasma. To probe at maximum stopping power, high-frequency pulsed ion bunches were decelerated to an energy of 0.5 MeV per nucleon. The ion energy loss was determined by a time-of-flight measurement using a specifically developed chemical-vapor-deposition diamond detector that was screened against any plasma radiation. A first experimental campaign was carried out using this newly developed platform, in which a precision better than 200 keV on the energy loss was reached. This allowed, via the knowledge of the plasma and of the beam parameters, to reliably test several stopping theories, either based on perturbation theory or on a nonlinear T-Matrix formalism. A preliminary

The Transmission Line for the SPIDER experiment

International Nuclear Information System (INIS)

Boldrin, Marco; De Lorenzi, Antonio; Recchia, Mauro; Toigo, Vanni; Bonicelli, Tullio; Simon, Muriel

2011-01-01

The 100 keV Ion Source Test facility - Source for the Production of Ions of Deuterium Extracted from RF plasma (SPIDER) - is aimed to test the full scale prototype of the Ion Source for the ITER 1 MeV Neutral Beam Injector (NBI). The SPIDER facility requires the construction of a High Voltage Deck (HVD) and of a High Voltage Transmission Line (TL) respectively to host the Ion Source Power Supplies system polarized at 100 kV and to carry the power and signal conductors to the beam accelerator. In already existing NBI systems with beam energy above 100 keV, the TL is realized with the SF 6 Gas Insulated Line technology. In the SPIDER TL case, the presence of a large inner conductor (half meter diameter), would make the pressurized TL a complex and costly component; therefore a free air insulated solution has been proposed. The paper focuses on the design of this TL, which has to host inside the complex high potential (100 kV) inner electrode a number of power and measuring conductors and has to minimize the Electro Magnetic Interferences (EMI) produced by the frequent grids breakdowns. Finite Element (FE) analyses have been performed to verify the configuration from the electrostatic point of view, to evaluate EMI screening effectiveness and to assess the impact of the relatively high thermal dissipation of power conductors located inside the high potential electrode. Moreover, an experimental test campaign has been carried out on a TL mockup to validate the TL electrostatic configuration under DC voltage. Finally, the paper reports on the status of procurement activities for the Transmission Line.

Status and plans for the development of a RF negative ion source for ITER NBI

International Nuclear Information System (INIS)

Franzen, P.; Falter, H.D.; Speth, E.; Kraus, W.; Bandyopadhyay, M.; Encheva, A.; Fantz, U.; Franke, Th.; Heinemann, B.; Holtum, D.; Martens, C.; McNeely, P.; Riedl, R.; Tanga, A.; Wilhelm, R.

2005-01-01

IPP Garching is currently developing a RF driven negative ion source for the ITER neutral beam injection system as an alternative to the present design with filamented sources. This paper reports an overview on the present status and the further prospects of the RF source development. Current densities of 26 mA/cm 2 and 15 mA/cm 2 have been achieved for hydrogen and deuterium, respectively, at a pressure of less than 0.5 Pa and an electron/ion ratio of 1. Size scaling experiments indicate a maximum extraction area which can be illuminated by a driver without losses of beam quality and uniformity. The preparation of a test facility for pulse lengths of up to 3600 s is proceeding; commissioning is expected end of 2004. As an intermediate step tests of a large source with the half size of the ITER source are foreseen to be commissioned in 2005

Development and application of high power and high intensity ion beam sources at NPI, Tomsk, Russia

International Nuclear Information System (INIS)

Ryabchikov, A.I.

2007-01-01

High - current ion beams have become a powerful tool for improving the surface properties of different materials. The prospects of wide commercial use of such beams for material treatment is not only due to the possibility of improving their properties, but, also for economic expediency. To achieve a high throughput and reduce the cost on ion beam material treatment, ion beams of high average and pulsed power are necessary. This paper gives an overview of work on generation of pulsed and repetitively pulsed beams of ion beams with currents ranging from fractions of an ampere to several tens of kA and with pulse duration from several tens of nanoseconds to several hundreds of microseconds. A number of different methods of materials surface properties modification using high power and intense ion beam and plasma are considered. (author)

Prototype tests on the ion source power supplies of the TEXTOR NI-system

International Nuclear Information System (INIS)

Goll, O.; Braunsberger, U.; Schwarz, U.

1987-01-01

The PINI ion source for the TEXTOR neutral injector is fed by a new modular transistorized power supply. All modules are located in a high voltage cage on 55 kV dc against ground. The normal operation of the injectors includes frequent grid breakdowns causing transient high voltage stresses on the ion source power supplies. These stresses must not disturb the safe operation of the power supplies. The paper describes the set up for extensive testing of a supply prototype module under the expected operating conditions. The main features of this test program are reviewed and the measures taken for a safe operation are discussed. As a result of the investigations, recommendations for the installation of the power supplies at the TEXTOR NI system are given

Status and plans for the development of an RF negative ion source for ITER NBI

International Nuclear Information System (INIS)

Falter, H.D.; Franzen, P.; Speth, E.; Kraus, W.; Bandyopadhyay, M.; Encheva, A.; Fantz, U.; Franke, Th.; Heinemann, B.; Holtum, D.; Martens, C.; McNeely, P.; Riedl, R.; Tanga, A.; Wilhelm, R.

2005-01-01

Inductively coupled RF ion sources are being developed at IPP for the production of negatively charged hydrogen ions. The source volume is approximately 50 litres. The extraction area varies between 70 and 300 cm 2 . With an extraction area of 70 cm 2 current densities of 26 mA/cm 2 for hydrogen and 16 mA/cm 2 for deuterium have been achieved. Experiments in deuterium have so far been very limited and the system is not yet optimised for deuterium. The RF source requires a pressure of at least 0.1 Pa in the driver. It is expected, that the ITER requirement of 0.3 Pa filling pressure can be met in a source with a relevant extraction area and gas flow. The co-extracted electron current can be kept at or near the level of the ion current. The extracted current scales almost linearly with extraction area and a current of 7.5 A has been extracted from a 306 cm 2 area. Due to the strong variation in filter field over the width of the grid so far only part of this current passes through the accelerator and is detected on the calorimeter. One of the test beds is at present being upgraded to allow one hour pulses and deuterium operation with approximately 250 cm 2 extraction area. A third test bed is being assembled to house a half size ITER source with approximately 1000 cm 2 extraction area. This so-called half size ITER source is being manufactured and will be used to demonstrate scalability of the RF source concept. (author)

The dynamics of a neoclassical tearing mode (NTM) influenced by energetic ions on EAST

International Nuclear Information System (INIS)

Li, Erzhong; Xu, L; Shi, T; Zhao, H; Liu, Y; Ti, A; Zhang, J; Huang, J; Shen, B; Lin, S; Qian, J; Gong, X; Hu, L; Igochine, V; White, R; Zhu, Y

2016-01-01

In the 2014 year’s campaign of experimental advanced superconducting tokamak (EAST), a series of Magnetohydrodynamics (MHD) instabilities were observed as the launching of Neutral Beam Injection (NBI), the most interesting one of which is the neoclassical tearing mode (NTM). Evidence clearly shows that a kink mode present after a strong sawtooth-like (ST-like) crash leaves a perturbation near the location of the magnetic island, providing the initial seed. The interaction of energetic ions makes the magnetic island oscillate both in island width and in rotation frequency. Analysis indicates that the bulk plasma still dominates the dynamics of NTM, and the orbit excursion of energetic ions induces a polarization current and modifies the width and rotation frequency of the neoclassical magnetic island. (paper)

Self-consistent analysis of radial electric field and fast ion losses in CHS Torsatron/Heliotron

International Nuclear Information System (INIS)

Sanuki, H.; Itoh, K.; Itoh, S.

1992-09-01

A self-consistent analysis is developed to determine the radial electric field and loss cone boundary in Torsatron/Heliotron plasmas under the influence of non-classical ion losses such as the loss cone loss ans charge exchange loss of fast ions with neutrals. Analysis is applied to the NBI heated plasmas in the Compact Helical System (CHS) device. Comparison is made between theoretical results and experimental observations. The increased ion particle losses caused by the orbit loss and charge exchange loss with neutrals make the radial electric field more negative than the value of purely neoclassical calculation. The partition of the injection energy among the shine through, direct orbit loss, change exchange loss and bulk heating is evaluated by using the self-consistent electric field profile. On-going experiments in the CHS device are briefly introduced. (author)

Design of power supply system for the prototype RF-driven negative ion source for neutral beam injection application

Energy Technology Data Exchange (ETDEWEB)

Jiang, Caichao; Hu, Chundong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate school, University of Science and Technology of China, Hefei 230026 (China); Wei, Jianglong, E-mail: jlwei@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Xie, Yahong; Xu, Yongjian; Liang, Lizhen; Chen, Shiyong; Liu, Sheng; Liu, Zhimin; Xie, Yuanlai [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2017-04-15

Highlights: • A supporting power supply system was designed in details for a RF-driven prototype negative ion source at ASIPP. • The RF power supply for plasma generation adopts an all-solid-state power supply structure. • The extraction grid power supply adopts the pulse step modulator (PSM) technology. - Abstract: In order to study the generation and extraction of negative ions for neutral beam injection application, a prototype RF-driven negative ion source and the corresponding test bed are under construction at Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). The target of the negative ion source is extracting a negation ion beam of 350 A/m{sup 2} for 3600 s plasma duration and 100 s beam duration. According to the required parameters of test bed, the design of power supply system is put forward for earlier study. In this paper, the performance requirements and design schemes of RF power supply for plasma generation, impedance matching network, bias voltage power supply, and extraction voltage power supply for negative beam extraction are introduced in details. The schemes provide a reference for the construction of power supply system and lay a foundation for the next phase of experimental operation.

Heavy-ion stopping powers and the low-velocity-projectile z3 effect

International Nuclear Information System (INIS)

Porter, L.E.

1977-01-01

Recent heavy-ion stopping-power measurements with elemental solid targets have been analyzed in order to ascertain the influence on effective ion charge of incorporating the low-velocity-projectile z 3 effect in Bethe-Bloch calculations. Shell corrections and the mean excitation energy of a given target were held fixed while searching for the best-fit value of a single charge-state parameter. In general, excellent fits to the stopping powers at projectile energies above 0.3 MeV/amu were achieved. Results of the present study compare very favorably with those from other extant methods of analysis

Measurements and modelling of fast-ion redistribution due to resonant MHD instabilities in MAST

International Nuclear Information System (INIS)

Jones, O M; Cecconello, M; Klimek, I; McClements, K G; Akers, R J; Keeling, D L; Meakins, A J; Sharapov, S E; Boeglin, W U; Perez, R V; Turnyanskiy, M

2015-01-01

The results of a comprehensive investigation into the effects of toroidicity-induced Alfvén eigenmodes (TAE) and energetic particle modes on the NBI-generated fast-ion population in MAST plasmas are reported. Fast-ion redistribution due to frequency-chirping TAE in the range 50 kHz–100 kHz and frequency-chirping energetic particle modes known as fishbones in the range 20 kHz–50 kHz, is observed. TAE and fishbones are also observed to cause losses of fast ions from the plasma. The spatial and temporal evolution of the fast-ion distribution is determined using a fission chamber, a radially-scanning collimated neutron flux monitor, a fast-ion deuterium alpha spectrometer and a charged fusion product detector. Modelling using the global transport analysis code Transp, with ad hoc anomalous diffusion and fishbone loss models introduced, reproduces the coarsest features of the affected fast-ion distribution in the presence of energetic particle-driven modes. The spectrally and spatially resolved measurements show, however, that these models do not fully capture the effects of chirping modes on the fast-ion distribution. (paper)

High-power ion beam generation with an inverse reflex tetrode

International Nuclear Information System (INIS)

Pasour, J.A.; Mahaffey, R.A.; Golden, J.; Kapetanakos, C.A.

1980-01-01

A new reflexing-electron ion source is described. The device produces a unidirectional ion beam with relatively high efficiency even when the applied magnetic field exceeds the self-field. This new source operates at a low, constant impedance during much of the applied voltage pulse and is better matched to available high-power, low-impedance generators than previous reflexing-electron devices. Proton pulses with peak current approx.500 kA have been produced with the inverse reflex tetrode coupled to the Gamble II generator

Temperature dependent power capability estimation of lithium-ion batteries for hybrid electric vehicles

International Nuclear Information System (INIS)

Zheng, Fangdan; Jiang, Jiuchun; Sun, Bingxiang; Zhang, Weige; Pecht, Michael

2016-01-01

The power capability of lithium-ion batteries affects the safety and reliability of hybrid electric vehicles and the estimate of power by battery management systems provides operating information for drivers. In this paper, lithium ion manganese oxide batteries are studied to illustrate the temperature dependency of power capability and an operating map of power capability is presented. Both parametric and non-parametric models are established in conditions of temperature, state of charge, and cell resistance to estimate the power capability. Six cells were tested and used for model development, training, and validation. Three samples underwent hybrid pulse power characterization tests at varied temperatures and were used for model parameter identification and model training. The other three were used for model validation. By comparison, the mean absolute error of the parametric model is about 29 W, and that of the non-parametric model is around 20 W. The mean relative errors of two models are 0.076 and 0.397, respectively. The parametric model has a higher accuracy in low temperature and state of charge conditions, while the non-parametric model has better estimation result in high temperature and state of charge conditions. Thus, two models can be utilized together to achieve a higher accuracy of power capability estimation. - Highlights: • The temperature dependency of power capability of lithium-ion battery is investigated. • The parametric and non-parametric power capability estimation models are proposed. • An exponential function is put forward to compensate the effects of temperature. • A comparative study on the accuracy of two models using statistical metrics is presented.

Field Trial on a Rack-mounted DC Power Supply System with 80-Ah Lithium-ion Batteries

Science.gov (United States)

Matsushima, Toshio

Using an industrial lithium-ion battery that has higher energy density than conventional valve-regulated lead-acid batteries, a rack-mounted DC-power-supply system was assembled and tested at a base transceiver station (BTS) offering actual services. A nominal output voltage and maximum output current of the system is 53.5V and 20A, respectively. An 80-Ah lithium-ion battery composed of 13 cells connected in series was applied in the system and maintained in a floating charge method. The DC-power-supply system was installed in a 19-inch power rack in the telecommunications equipment box at BTS. The characteristics of the 80Ah lithium-ion battery, specifications of the DC-power-supply system and field-test results were shown in this paper.

Measurement of stopping power of light ions

International Nuclear Information System (INIS)

Sakamoto, Naoki

1981-01-01

The stopping power of light ions penetrating various materials has been measured. The data of proton stopping power and the mean ionization potentials are presented. The experiments were made by using the 6.75 MeV protons from a cyclotron and the protons in the energy range from 3 to 9 MeV from a tandem Van de Graaff. The windows with and without sample-foils were rotated in front of a semiconductor detector, and the measured energy loss and the thickness of the sample foils were used to estimate the energy loss at the mean energy of protons in the samples. The analyses were made by considering the inner shell correction, Z 1 3 correction and the Bloch correction. The mean ionization potentials were derived from the data. (Kato, T.)

Lithium-Ion Battery Power Degradation Modelling by Electrochemical Impedance Spectroscopy

DEFF Research Database (Denmark)

Stroe, Daniel-Ioan; Swierczynski, Maciej Jozef; Stroe, Ana-Irina

2017-01-01

This paper investigates the use of the electrochemical impedance spectroscopy (EIS) technique as an alternative to the DC pulses technique for estimating the power capability decrease of Lithium-ion batteries during calendar ageing. Based on results obtained from calendar ageing tests performed...... at different conditions during one to two years, a generalized model that estimates the battery power capability decrease as function of the resistance Rs increase (obtained from EIS) was proposed and successfully verified....

Ion energy characteristics downstream of a high power helicon

International Nuclear Information System (INIS)

Prager, James; Winglee, Robert; Ziemba, Tim; Roberson, B Race; Quetin, Gregory

2008-01-01

The High Power Helicon eXperiment operates at higher powers (37 kW) and lower background neutral pressure than other helicon experiments. The ion velocity distribution function (IVDF) has been measured at multiple locations downstream of the helicon source and a mach 3-6 flowing plasma was observed. The helicon antenna has a direct effect in accelerating the plasma downstream of the source. Also, the IVDF is affected by the cloud of neutrals from the initial gas puff, which keeps the plasma speed low at early times near the source.

Ion energy characteristics downstream of a high power helicon

Energy Technology Data Exchange (ETDEWEB)

Prager, James; Winglee, Robert; Ziemba, Tim; Roberson, B Race; Quetin, Gregory [University of Washington, Johnson Hall 070, Box 351310, 4000 15th Avenue NE, Seattle, WA 98195-1310 (United States)], E-mail: jprager@u.washington.edu

2008-05-01

The High Power Helicon eXperiment operates at higher powers (37 kW) and lower background neutral pressure than other helicon experiments. The ion velocity distribution function (IVDF) has been measured at multiple locations downstream of the helicon source and a mach 3-6 flowing plasma was observed. The helicon antenna has a direct effect in accelerating the plasma downstream of the source. Also, the IVDF is affected by the cloud of neutrals from the initial gas puff, which keeps the plasma speed low at early times near the source.

Towards a realistic 3D simulation of the extraction region in ITER NBI relevant ion source

International Nuclear Information System (INIS)

Mochalskyy, S.; Wünderlich, D.; Fantz, U.; Franzen, P.; Minea, T.

2015-01-01

The development of negative ion (NI) sources for ITER is strongly accompanied by modelling activities. The ONIX code addresses the physics of formation and extraction of negative hydrogen ions at caesiated sources as well as the amount of co-extracted electrons. In order to be closer to the experimental conditions the code has been improved. It includes now the bias potential applied to first grid (plasma grid) of the extraction system, and the presence of Cs + ions in the plasma. The simulation results show that such aspects play an important role for the formation of an ion–ion plasma in the boundary region by reducing the depth of the negative potential well in vicinity to the plasma grid that limits the extraction of the NIs produced at the Cs covered plasma grid surface. The influence of the initial temperature of the surface produced NI and its emission rate on the NI density in the bulk plasma that in turn affects the beam formation region was analysed. The formation of the plasma meniscus, the boundary between the plasma and the beam, was investigated for the extraction potentials of 5 and 10 kV. At the smaller extraction potential the meniscus moves closer to the plasma grid but as in the case of 10 kV the deepest meniscus bend point is still outside of the aperture. Finally, a plasma containing the same amount of NI and electrons (n H − =n e =10 17 m −3 ), representing good source conditioning, was simulated. It is shown that at such conditions the extracted NI current can reach values of ∼32 mA cm −2 using ITER-relevant extraction potential of 10 kV and ∼19 mA cm −2 at 5 kV. These results are in good agreement with experimental measurements performed at the small scale ITER prototype source at the test facility BATMAN. (paper)

Effects of nuclear elastic scattering and modifications of ion-electron equilibration power on advanced-fuel burns

International Nuclear Information System (INIS)

Galambos, J.D.

1983-01-01

The effects of Nuclear Elastic Scattering (NES) of fusion products and modifications of the ion-electron equilibration power on D-T and D-based advanced-fuel fusion plasmas are presented here. The processes causing the modifications to the equilibration power included here are: (1) depletion of low-energy electrons by Coulomb collisions with the ions; and (2) magnetic field effects on the energy transfer between the ions and the electrons. Both NES and the equilibration modifications affect the flow of power to the plasma ions, which is an important factor in the analysis of advanced-fuels. A Hot Ion Mode (HIM) analysis was used to investigate the changes in the minimum ignition requirements for Cat-D and D- 3 He plasmas, due to the changes in the allowable T/sub i/T/sub e/ for ignition from NES and equilibration modifications. Both of these effects have the strongest influence on the ignition requirements for high temperature (>50 keV), low beta (<15%) plasmas, where the cyclotron radiation power loss from the electrons (which is particularly sensitive to changes in the electron temperature) is large

Range and stopping power tables for 2.5-12MeV/nucleon heavy ions in solids

International Nuclear Information System (INIS)

Hubert, F.; Fleury, A.; Bimbot, R.; Gardes, D.

1978-12-01

A semi-empirical procedure to compute heavy ion stopping powers is presented. The calculations use recent stopping power values for alpha particles and a new parameterization for the effective charge taking into account the effect to the stopping medium. Stopping powers and ranges are tabulated for moving ions of atomic number 2<=Z<=45 in the energy region 2.5<=E/A<=12 MeV/nucleon for 18 solid materials

Validation of the kinetic-turbulent-neoclassical theory for edge intrinsic rotation in DIII-D

Science.gov (United States)

Ashourvan, Arash; Grierson, B. A.; Battaglia, D. J.; Haskey, S. R.; Stoltzfus-Dueck, T.

2018-05-01

In a recent kinetic model of edge main-ion (deuterium) toroidal velocity, intrinsic rotation results from neoclassical orbits in an inhomogeneous turbulent field [T. Stoltzfus-Dueck, Phys. Rev. Lett. 108, 065002 (2012)]. This model predicts a value for the toroidal velocity that is co-current for a typical inboard X-point plasma at the core-edge boundary (ρ ˜ 0.9). Using this model, the velocity prediction is tested on the DIII-D tokamak for a database of L-mode and H-mode plasmas with nominally low neutral beam torque, including both signs of plasma current. Values for the flux-surface-averaged main-ion rotation velocity in the database are obtained from the impurity carbon rotation by analytically calculating the main-ion—impurity neoclassical offset. The deuterium rotation obtained in this manner has been validated by direct main-ion measurements for a limited number of cases. Key theoretical parameters of ion temperature and turbulent scale length are varied across a wide range in an experimental database of discharges. Using a characteristic electron temperature scale length as a proxy for a turbulent scale length, the predicted main-ion rotation velocity has a general agreement with the experimental measurements for neutral beam injection (NBI) powers in the range PNBI balanced—but high powered—NBI, the net injected torque through the edge can exceed 1 Nm in the counter-current direction. The theory model has been extended to compute the rotation degradation from this counter-current NBI torque by solving a reduced momentum evolution equation for the edge and found the revised velocity prediction to be in agreement with experiment. Using the theory modeled—and now tested—velocity to predict the bulk plasma rotation opens up a path to more confidently projecting the confinement and stability in ITER.

Stopping powers of gases for ions of energy below 200 keV

International Nuclear Information System (INIS)

Fukuda, Akira

1978-01-01

There has been renewed interest in the stopping power of matters for ions in low energy region. But there is not an established theory in this energy region, and experimental data did not coincide with the curves in some data books. Therefore, precise experimental measurement is still necessary. In present neutron dosimetry, tissues are the object of measurement of absorbed dose. In this experiment, it was intended to use tissue equivalent gas as a target gas. In the experimental apparatus, ions come from the Cockcroft-Walton accelerator are applied to the cell, in which the target gas is admitted from gas source. Gas in the cell is observed with the electrostatic energy analyzer. Stopping power is calculated from the results of energy loss measurement. In this report, only the preliminary results are shown. The tissue equivalent gas is composed of CH 4 , CO 2 and N 2 , each percentage is 64.95, 32.2 and 2.85, respectively. It seems that the stopping powers of noble gases will be useful for the developments of the theory, and the stopping power for He + ions was measured. The results are shown in a figure, and the errors were estimated to be less than 1.5%. At the end of the report, some discussions among a few persons are added. (Wakatsuki, Y.)

Simulation of RF power and multi-cusp magnetic field requirement for H{sup −} ion sources

Energy Technology Data Exchange (ETDEWEB)

Pathak, Manish [Ion Source Lab., Proton Linac & Superconducting Cavities Division, Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India); Senecha, V.K., E-mail: kumarvsen@gmail.com [Ion Source Lab., Proton Linac & Superconducting Cavities Division, Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India); Homi Bhabha National Institute, Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India); Kumar, Rajnish; Ghodke, Dharmraj V. [Ion Source Lab., Proton Linac & Superconducting Cavities Division, Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India)

2016-12-01

A computer simulation study for multi-cusp RF based H{sup −} ion source has been carried out using energy and particle balance equation for inductively coupled uniformly dense plasma considering sheath formation near the boundary wall of the plasma chamber for RF ion source used as high current injector for 1 Gev H{sup −} Linac project for SNS applications. The average reaction rates for different reactions responsible for H{sup −} ion production and destruction have been considered in the simulation model. The RF power requirement for the caesium free H{sup -} ion source for a maximum possible H{sup −} ion beam current has been derived by evaluating the required current and RF voltage fed to the coil antenna using transformer model for Inductively Coupled Plasma (ICP). Different parameters of RF based H{sup −} ion source like excited hydrogen molecular density, H{sup −} ion density, RF voltage and current of RF antenna have been calculated through simulations in the presence and absence of multicusp magnetic field to distinctly observe the effect of multicusp field. The RF power evaluated for different H{sup −} ion current values have been compared with the experimental reported results showing reasonably good agreement considering the fact that some RF power will be reflected from the plasma medium. The results obtained have helped in understanding the optimum field strength and field free regions suitable for volume emission based H{sup −} ion sources. The compact RF ion source exhibits nearly 6 times better efficiency compare to large diameter ion source.

Method for enhancing the resolving power of ion mobility separations over a limited mobility range

Science.gov (United States)

Shvartsburg, Alexandre A; Tang, Keqi; Smith, Richard D

2014-09-23

A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments. The approach also enables low-cutoff, high-cutoff, and bandpass ion mobility filters.

Power-law distributions for a trapped ion interacting with a classical buffer gas.

Science.gov (United States)

DeVoe, Ralph G

2009-02-13

Classical collisions with an ideal gas generate non-Maxwellian distribution functions for a single ion in a radio frequency ion trap. The distributions have power-law tails whose exponent depends on the ratio of buffer gas to ion mass. This provides a statistical explanation for the previously observed transition from cooling to heating. Monte Carlo results approximate a Tsallis distribution over a wide range of parameters and have ab initio agreement with experiment.

Power balance limit in collective ion acceleration

International Nuclear Information System (INIS)

Olson, C.L.

1978-01-01

The power balance limit to the IREB beam front propagation velocity, as first applied to the problem of collective ion acceleration by Olson in 1973, is investigated in view of recent data of Ecker and Putnam. The beam front velocity β/sub f/c as a function of IREB impedance Z is given, showing the dependence on the power balance limit, the ionization front velocity, and the runaway cutoff. The Olson theory predictions, with no fitted parameters, are shown to be in agreement with the data. Further comparisons of β/sub f/ with respect to the IREB electron energy, the IREB current, and the neutral gas pressure are given. Various forms for the power balance limit are discussed; it is shown that inclusion of the secondary electron power loss term results in an essentially negligible correction to β/sub f/ for typical data parameters. The power balance limit used by Ecker and Putnam is shown to be simply a 3-parameter curve fit, wherein the fitted parameters must exceed their allowed physical values to obtain a reasonable fit for β/sub f/ vs Z. Further, it is shown that this curve fitting leads to serious disagreements with other aspects of the data. It is concluded that the original Olson theory adequately accounts for the data, and that the power balance limit for IREB/gas data is typically not significant except for very small values of Z

Impacts of the CX neutrals on the Vacuum Vessel of TJ-II during NBI

International Nuclear Information System (INIS)

Guasp, J.

1995-09-01

A numerical analysis of the impact patterns on the Vacuum Vessel produced by CX neutrals during the tangential balanced NBI in TJ-II Helical Axis Stellerator has been done. The results show periodical distribution with smooth maxima and mild loads, concentrated prefentlyon the HC plates. A certain preference of these neutral to emerge downwards from the plasma appears, as consequence of a similar trend for the trapped particles. The differences between the impacts produced by the beam paralel to the magnetic field and the opposite one are small, once more as a consequence of the loss of memory of trapped particles to initial direction. The dependence of loads with plasma density and beam energy follows the trend of CX losses, decreasing strongly with increasing density and decreasing, more smoothly, with energy

MHD induced fast-ion losses on ASDEX Upgrade

International Nuclear Information System (INIS)

GarcIa-Munoz, M.; Fahrbach, H.-U.; Bobkov, V.; Bruedgam, M.; Guenter, S.; Igochine, V.; Lauber, Ph.; Mantsinen, M.J.; Maraschek, M.; Poli, E.; Sassenberg, K.; Tardini, G.; Zohm, H.; Pinches, S.D.; Gobbin, M.; Marrelli, L.; Martin, P.; Piovesan, P.

2009-01-01

A detailed knowledge of the interplay between MHD instabilities and energetic particles has been gained from direct measurements of fast-ion losses (FILs). Time-resolved energy and pitch angle measurements of FIL caused by neoclassical tearing modes (NTMs) and toroidicity-induced Alfven eigenmodes (TAEs) have been obtained using a scintillator based FIL detector. The study of FIL due to TAEs has revealed the existence of a new core-localized MHD fluctuation, the Sierpes mode. The Sierpes mode is a non-pure Alfvenic fluctuation which appears in the acoustic branch, dominating the transport of fast-ions in ICRF heated discharges. The internal structure of both TAEs and Sierpes mode has been reconstructed by means of highly resolved multichord soft x-ray measurements. A spatial overlapping of their eigenfunctions leads to a FIL coupling, showing the strong influence that a core-localized fast-ion driven MHD instability may have on the fast-ion transport. We have identified the FIL mechanisms due to NTMs as well as due to TAEs. Drift islands formed by fast-ions in particle phase space are responsible for the loss of NBI fast-ions due to NTMs. In ICRF heated plasmas, a resonance condition fulfilled by the characteristic trapped fast-ion orbit frequencies leads to a phase matching between fast-ion orbit and NTM or TAE magnetic fluctuation. The banana tips of a resonant trapped fast-ion bounce radially due to an E x B drift in the TAE case. The NTM radial bounce of the fast-ion banana tips is caused by the radial component of the perturbed magnetic field lines.

Development on JET of Advanced Tokamak Operations for ITER

International Nuclear Information System (INIS)

Tuccillo, A.A.; Crisanti, F.; Litaudon, X.

2005-01-01

Recent research on Advanced Tokamak in JET has focused on scenarii with both monotonic and reversed shear q profiles having plasma parameters as relevant as possible for extrapolation to ITER. Wide ITBs, R∼3.7m, are formed at ITER relevant triangularity δ∼0.45, with n e /n G ∼60% and ELMs moderated by Ne injection. At higher current (I P ≤3.5MA, δ∼0.25) wide ITBs sitting at R≥ 3.5m (positive shear region) have been developed, generally MHD events terminate these barrier otherwise limited in strength by power availability. ITBs with core density close to Greenwald value are obtained with plasma target preformed by opportune timing of LHCD, pellet injection and small amount of NBI power. ITB start with toroidal rotation 4 times lower than the standard NBI heated ITBs. Full CD is achieved in reversed shear ITBs at 3T/1.8 MA, by using 10MW NBI, 5MW ICRH and 3MW LH. Wide ITBs located at R=3.6m, without impurity accumulation and type-III ELMs edge can be sustained for a time close to neo-classical resistive time. These discharges have been extended to the maximum duration allowed by subsystems (20s) with the JET record of injected energy: E∼330 MJ. Integrated control of pressure and current profile isit; feature used in these discharges. Central ICRF mode conversion electron heating, added to about 14MW NBI power, produced impressive ITBs with equivalent Q DT ∼ 0.25. Conversely ion ITBs are obtained with low torque injection, by ICRH 3 He minority heating of ions, on pure LHCD electron ITBs. Similarity experiments between JET and AUG have compared the dynamics of ITBs and have been the starting point of Hybrid Scenarios activity, then developed at ρ* as low as ρ*∼3*10 -3 . The development of hybrid regime with dominant electron heating has also started. Injection of trace of tritium and a mixture of Ar/Ne allowed studying fuel and impurities transport in many of the explored AT scenarios. (author)

Heat transfer enhancement of NBI vacuum pump cryopanels

International Nuclear Information System (INIS)

Ochoa Guaman, Santiago; Hanke, Stefan; Day, Christian

2013-01-01

Highlights: ► Cryopanel is optimized minimizing its maximal temperature rise and heat capacity. ► Copper coating on the cryopanels is necessary to reach a high thermal efficiency. ► The copper coating is achieved using an electroplating technique. ► A thermal shield for the cryopump 4 K manifold would reduce heat leaks down to 10%. ► The manufacturability and operation of the thermal shield is discussed. -- Abstract: Huge cryogenic pumps are installed inside neutral beam injectors in order to manage the typically very large gas flows. This paper deals with the aspect of passive cooling in NBI cryopump design development and discusses design considerations in two example areas. One is the design of cryopanels consisting of a pipe, centrally supplied with cryogenic helium, and a welded fin, passively cooled, to provide the necessary pumping surface below a given maximum temperature. The results of several parametric simulations in ANSYS are presented using different copper thicknesses and cryopanel geometries to discuss the thermal capability (heat transfer characteristics and heat capacities) of a number of design variants. The optimum design solution is based on copper-coated fins, using an electroplating technique, and thereby improving the heat transfer of the cryopanels while attaining an overall reduction in weight. The other area is the sound design of the manifold shielding system with a weld contact between copper and stainless steel. Weld samples were manufactured and investigated to raise awareness of the demands and risks during manufacturing and to demonstrate that readily applicable weld procedures exist

Removal of toxic uranium from synthetic nuclear power reactor effluents using uranyl ion imprinted polymer particles.

Science.gov (United States)

Preetha, Chandrika Ravindran; Gladis, Joseph Mary; Rao, Talasila Prasada; Venkateswaran, Gopala

2006-05-01

Major quantities of uranium find use as nuclear fuel in nuclear power reactors. In view of the extreme toxicity of uranium and consequent stringent limits fixed by WHO and various national governments, it is essential to remove uranium from nuclear power reactor effluents before discharge into environment. Ion imprinted polymer (IIP) materials have traditionally been used for the recovery of uranium from dilute aqueous solutions prior to detection or from seawater. We now describe the use of IIP materials for selective removal of uranium from a typical synthetic nuclear power reactor effluent. The IIP materials were prepared for uranyl ion (imprint ion) by forming binary salicylaldoxime (SALO) or 4-vinylpyridine (VP) or ternary SALO-VP complexes in 2-methoxyethanol (porogen) and copolymerizing in the presence of styrene (monomer), divinylbenzene (cross-linking monomer), and 2,2'-azobisisobutyronitrile (initiator). The resulting materials were then ground and sieved to obtain unleached polymer particles. Leached IIP particles were obtained by leaching the imprint ions with 6.0 M HCl. Control polymer particles were also prepared analogously without the imprint ion. The IIP particles obtained with ternary complex alone gave quantitative removal of uranyl ion in the pH range 3.5-5.0 with as low as 0.08 g. The retention capacity of uranyl IIP particles was found to be 98.50 mg/g of polymer. The present study successfully demonstrates the feasibility of removing uranyl ions selectively in the range 5 microg - 300 mg present in 500 mL of synthetic nuclear power reactor effluent containing a host of other inorganic species.

Experimental Investigations from the Operation of a 2 Kw Brayton Power Conversion Unit and a Xenon Ion Thruster

Science.gov (United States)

Mason, Lee; Birchenough, Arthur; Pinero, Luis

2004-01-01

A 2 kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton converters and ion thrusters are potential candidates for use on future high power NEP missions such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of existing lower power test hardware provided a cost-effective means to investigate the critical electrical interface between the power conversion system and ion propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

Silicon-Based Lithium-Ion Capacitor for High Energy and High Power Application

Science.gov (United States)

Wu, James J.; Demattia, Brianne; Loyselle, Patricia; Reid, Concha; Kohout, Lisa

2017-01-01

Si-based Li-ion capacitor has been developed and demonstrated. The results show it is feasible to improve both power density and energy density in this configuration. The applied current density impacts the power and energy density: low current favors energy density while high current favors power density. Active carbon has a better rate capability than Si. Next StepsFuture Directions. Si electrode needs to be further studied and improved. Further optimization of SiAC ratio and evaluation of its impact on energy density and power density.

Vectorization and improvement of nuclear codes (MEUDAS4, FORCE, STREAM V2.6, HEATING7-VP, SCDAP/RELAP5/MOD2.5, NBI3DGFN)

International Nuclear Information System (INIS)

Nemoto, Toshiyuki; Suzuki, Koichiro; Isobe, Nobuo; Machida, Masahiko; Osanai, Seiji; Yokokawa, Mitsuo

1992-09-01

Eight nuclear codes have been vectorized and modified to improve their performance. These codes are magnetic fluid equilibrium code MEUDAS4 (CR and FFT versions), the magnetic field analysis code FORCE, the three-dimensional heat fluid analysis code STREAM V2.6, the three-dimensional heat analysis code HEATING 7-VP, the severe accident transient analysis code SCDAP/RELAP 5/MOD 2.5 for light water reactors, the ion beam orbital analysis code NBI3DGFN, and a free electron laser analysis code. The speedup ratios of the vectorized versions to the original ones in scalar mode are 2.3-4.9, 1.9-5.4, 2.6-6.2, and 1.9 for the MEUDAS4, STREAM, FORCE, and free electron laser analysis code, respectively. The definition method of the computational regions in the HEATING7-VP is improved. The SCDAP/RELAP5/MOD2.5 is modified to use extended memory regions of the computer. In this report, outlines of the codes, techniques used in the vectorization and reorganization of the codes, verification of computed results, and improvement on the performance are presented. (author)

Beam diagnostic tools for the negative hydrogen ion source test facility ELISE

International Nuclear Information System (INIS)

Nocentini, Riccardo; Fantz, Ursel; Franzen, Peter; Froeschle, Markus; Heinemann, Bernd; Riedl, Rudolf; Ruf, Benjamin; Wuenderlich, Dirk

2013-01-01

Highlights: ► We present an overview of beam diagnostic tools foreseen for the new testbed ELISE. ► A sophisticated diagnostic calorimeter allows beam profile measurement. ► A tungsten wire mesh in the beam path provides a qualitative picture of the beam. ► Stripping losses and beam divergence are measured by H α Doppler shift spectroscopy. -- Abstract: The test facility ELISE, presently being commissioned at IPP, is a first step in the R and D roadmap for the RF driven ion source and extraction system of the ITER NBI system. The “half-size” ITER-like test facility includes a negative hydrogen ion source that can be operated for 1 h. ELISE is expected to extract an ion beam of 20 A at 60 kV for 10 s every 3 min, therefore delivering a total power of 1.2 MW. The extraction area has a geometry that closely reproduces the ITER design, with the same width and half the height, i.e. 1 m × 1 m. This paper presents an overview of beam diagnostic tools foreseen for ELISE. For the commissioning phase, a simple beam dump with basic diagnostic capabilities has been installed. In the second phase, the beam dump will be substituted by a more sophisticated diagnostic calorimeter to allow beam profile measurement. Additionally, a tungsten wire mesh will be introduced in the beam path to provide a qualitative picture of beam size and position. Stripping losses and beam divergence will be measured by means of H α Doppler shift spectroscopy. An absolute calibration is foreseen in order to measure beam intensity

The 100 kV Faraday cage (High Voltage Deck) for the SPIDER experiment

International Nuclear Information System (INIS)

Boldrin, Marco; Grando, Luca; Pesce, Alberto; Recchia, Mauro; Toigo, Vanni; Gutierrez, Daniel; Simon, Muriel; Faoro, Giovanni; Guion, Andrea; Maggiora, Edoardo; Pedron, Diego; Roman, Anita; Decamps, Hans

2015-01-01

Highlights: • A 100 keV experiment is under construction to optimize ITER NBI Ion Source. • The Ion Source Power Supplies are hosted inside a wide −100 kVdc Faraday cage (HVD). • The paper reports on the design solutions of the HVD. • Electrostatic and electromagnetic analyses are presented. • Procurement activities status is reported. - Abstract: In order to optimize the design and operation of the Ion Source for the ITER Neutral Beam Injector (NBI), a dedicated 100 keV Ion Source, identified as Source for the Production of Ions of Deuterium Extracted from RF plasma (SPIDER), is under construction in the Neutral Beam Test Facility, at the Consorzio RFX premises, in Padua, Italy. The Ion Source, polarized at −112 kVdc voltage, will produce negative ions (Deuterium D"− or Hydrogen H"−) which, extracted from the Plasma Grid with an extraction voltage up to 12 keV, are accelerated up to 100 keV by the 100 kVdc Power Supply (100 kV PS). The required Ion Source and the Extraction Power Supplies (ISEPS) system and the associated diagnostics are hosted inside a High Voltage Deck (HVD), a −100 kVdc air-insulated Faraday cage. These power supplies and various diagnostics and control equipment are connected to the Ion Source by means of a High Voltage Transmission Line (TL). The HVD (procurement started mid 2013; delivery on site in the second half of 2014) will consist of a wide structure (13 m (L) × 11 m (W) × 5 m (H)), designed to support the weight of the ISEPS components, mounted on supporting insulators and clad with a conductive metal sheet in order to reduce the electromagnetic interference (EMI). The paper reports on the design solutions of the HVD focusing on insulation, mechanical, thermal and EMI issues. The details of the main HVD interfaces with the TL and with insulating transformer are also described. Finite Element (FE) analyses have been performed, on the one hand, to verify the configuration from the electrostatic point of view and

The 100 kV Faraday cage (High Voltage Deck) for the SPIDER experiment

Energy Technology Data Exchange (ETDEWEB)

Boldrin, Marco, E-mail: marco.boldrin@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete S.p.A.), Corso Stati Uniti 4, 35127 Padova (Italy); Grando, Luca; Pesce, Alberto; Recchia, Mauro; Toigo, Vanni [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete S.p.A.), Corso Stati Uniti 4, 35127 Padova (Italy); Gutierrez, Daniel; Simon, Muriel [Fusion for Energy, c/o Josep Pla 2, 08019 Barcelona (Spain); Faoro, Giovanni; Guion, Andrea; Maggiora, Edoardo; Pedron, Diego [COELME – Costruzioni Elettromeccaniche S.p.A., via G. Galilei no. 1/2, 30036 S. Maria di Sala, Venezia (Italy); Roman, Anita [Studio di Ingegneria RS s.r.l., Viale dell’Arcella 1, 35153 Padova (Italy); Decamps, Hans [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France)

2015-10-15

Highlights: • A 100 keV experiment is under construction to optimize ITER NBI Ion Source. • The Ion Source Power Supplies are hosted inside a wide −100 kVdc Faraday cage (HVD). • The paper reports on the design solutions of the HVD. • Electrostatic and electromagnetic analyses are presented. • Procurement activities status is reported. - Abstract: In order to optimize the design and operation of the Ion Source for the ITER Neutral Beam Injector (NBI), a dedicated 100 keV Ion Source, identified as Source for the Production of Ions of Deuterium Extracted from RF plasma (SPIDER), is under construction in the Neutral Beam Test Facility, at the Consorzio RFX premises, in Padua, Italy. The Ion Source, polarized at −112 kVdc voltage, will produce negative ions (Deuterium D{sup −} or Hydrogen H{sup −}) which, extracted from the Plasma Grid with an extraction voltage up to 12 keV, are accelerated up to 100 keV by the 100 kVdc Power Supply (100 kV PS). The required Ion Source and the Extraction Power Supplies (ISEPS) system and the associated diagnostics are hosted inside a High Voltage Deck (HVD), a −100 kVdc air-insulated Faraday cage. These power supplies and various diagnostics and control equipment are connected to the Ion Source by means of a High Voltage Transmission Line (TL). The HVD (procurement started mid 2013; delivery on site in the second half of 2014) will consist of a wide structure (13 m (L) × 11 m (W) × 5 m (H)), designed to support the weight of the ISEPS components, mounted on supporting insulators and clad with a conductive metal sheet in order to reduce the electromagnetic interference (EMI). The paper reports on the design solutions of the HVD focusing on insulation, mechanical, thermal and EMI issues. The details of the main HVD interfaces with the TL and with insulating transformer are also described. Finite Element (FE) analyses have been performed, on the one hand, to verify the configuration from the electrostatic point of

High power heating in the ion cyclotron range of frequencies in the Wisconsin Tokapole II

International Nuclear Information System (INIS)

Biddle, A.P.; Sprott, J.C.

1981-01-01

Fast wave heating at the second, third and fourth harmonics of the ion cyclotron resonance, and slow wave heating at the fundamental in a single ion species hydrogen plasma, are found to be in good agreement with warm plasma theory at rf power levels <= 130 kW. Ion heating is negligible off an eigenmode. Ion body temperatures are more than doubled to 75 eV from the 35 eV ohmically heated case with tails comprising 8% of the plasma at 320 eV. No deleterious effects except a non-disruptive 10% shortening of the discharge length caused by impurity influx are noted. A passive mode tracking technique allows approximately equal to 40% increase in power deposition in a passing eigenmode over that of a fixed frequency rf source. Ion temperatures are limited by charge exchange due to the < 50 eV central temperature and the small 13 cm radius current channel. (author)

Spectroscopic investigation of heavy impurity behaviour during ICRH with the JET ITER-like wall

Energy Technology Data Exchange (ETDEWEB)

Czarnecka, A. [Institute of Plasma Physics and Laser Microfusion, Association EURATOM-IPPLM, Hery 23 Str., 01-497 Warsaw (Poland); Bobkov, V.; Maggi, C.; Pütterich, T. [Max-Planck-Institut für Plasmaphysik, EURATOM-Association, D-85748 Garching (Germany); Coffey, I. H. [Department of Physics, Queen' s University, Belfast, BT7 1NN, Northern Ireland (United Kingdom); Colas, L. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Jacquet, P.; Lawson, K. D. [Euratom/CCFE Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Lerche, E.; Van Eester, D. [Association EURATOM - Belgian State, ERM-KMS, TEC Partner (Belgium); Mayoral, M.-L. [Euratom/CCFE Association, Culham Science Centre, Abingdon, OX14 3DB, UK and EFDA Close Support Unit, Garching (Germany); Collaboration: JET-EFDA Contributors

2014-02-12

Magnetically confined plasmas, such as those produced in the tokamak JET, contain measurable amounts of impurity ions produced during plasma-wall interactions (PWI) from the plasma-facing components and recessed wall areas. The impurities, including high- and mid-Z elements such as tungsten (W) from first wall tiles and nickel (Ni) from Inconel structure material, need to be controlled within tolerable limits, to ensure they do not significantly affect the performance of the plasma. This contribution focuses on documenting W and Ni impurity behavior during Ion Cyclotron Resonance Heating (ICRH) operation with the new ITER-Like Wall (ILW). Ni- and W-concentration were derived from VUV spectroscopy and the impact of applied power level, relative phasing of the antenna straps, plasma separatrix - antenna strap distance, IC resonance position, edge density and different plasma configuration, on the impurity release during ICRH are presented. For the same ICRH power the Ni and W concentration was lower with dipole phasing than in the case of −π/2 phasing. The Ni concentration was found to increase with ICRH power and for the same NBI power level, ICRH-heated plasmas were characterized by two times higher Ni impurity content. Both W and Ni concentrations increased strongly with decreasing edge density which is equivalent to higher edge electron temperatures and more energetic ions responsible for the sputtering. In either case higher levels were found in ICRH than in NBI heated discharges. When the central plasma temperature was similar, ICRH on-axis heating resulted in higher core Ni impurity concentration in comparison to off-axis ICRH in L-mode. It was also found that the main core radiation during ICRH came from W.

Impacts of the CX neutrals on the Vacuum Vessel of TJ-II during NBI

International Nuclear Information System (INIS)

Guasp, J.

1995-01-01

A numerical analysis of the impact patterns on the Vacuum Vessel produced by CX neutrals during the tangential balanced NBI in TJ-II Helical Axis Stellarator has been done. The results show periodical distributions with smooth maxima and mild loads, concentrated preferential on the HC plates. A certain preference of these neutral to emerge down wards from the plasma appears, as a consequence of a similar trend for the trapped particles. The differences between the impacts produced by the beam parallel to the magnetic field and the opposite one are small, once more as a consequence of the loss of memory of trapped particles to initial direction. The dependence of loads with plasma density and beam energy follows the trend of CX losses, decreasing strongly with increasing density and decreasing, more smoothly, with energy. (Author) 3 refs

Numerical study of power generation by reverse electrodialysis in ion-selective nanochannels

International Nuclear Information System (INIS)

Kim, Dong Kwon

2011-01-01

In this article, ion-selective nanochannels are numerically studied to investigate the power generation capability of a concentration gradient in conjunction with reverse electrodialysis. The generation of power from the nanochannel when it is placed between two reservoirs containing sodium chloride solutions with different concentrations is investigated. The current-potential characteristics of the nanochannel were calculated by solving the Poisson equation and the Nernst-Planck equation. The effects of engineering parameters on the power generation density are investigated

Numerical study of power generation by reverse electrodialysis in ion-selective nanochannels

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Kwon [Ajou University, Suwon (Korea, Republic of)

2011-01-15

In this article, ion-selective nanochannels are numerically studied to investigate the power generation capability of a concentration gradient in conjunction with reverse electrodialysis. The generation of power from the nanochannel when it is placed between two reservoirs containing sodium chloride solutions with different concentrations is investigated. The current-potential characteristics of the nanochannel were calculated by solving the Poisson equation and the Nernst-Planck equation. The effects of engineering parameters on the power generation density are investigated.

LIBRA-LiTE: A commercial size light ion fusion power plant

International Nuclear Information System (INIS)

Badger, B.; Choi, B.; Engelstad, R.L.; Kulcinski, G.L.; Lovell, E.G.; MacFarlane, J.J.; Mogehed, E.A.; Moses, G.A.; Peterson, R.R.; Rutledge, S.; Sawan, M.E.; Sviatoslavsky, G.; Sviatoslavsky, I.N.; Wittenberg, L.J.

1992-05-01

LIBRA-LiTE is a concept study for future 1000 MWe nuclear fusion reactors operating on the principle of inertial confinement. Light ions, e.g. lithium ions, are given an energy of 25-35 MeV in an accelerator and focused symmetrically onto a target (deuterium-tritium filled sphere of 7 mm diameter) in a reactor chamber. The fusion reaction is ignited by shock wave induced compression of the target. The radiation (photons, neutrons, ions) is absorbed in a blanket where the thermal power is removed by a coolant and tritium is rebred. The LIBRA-LiTE concept study is the continuation of the earlier LIBRA study (330 MWe) with a modified concept of light ion beam focusing. Starting from an ion source (diode), the lithium ion beams are focused ballistically onto the target. For this to be achieved, lithium must be used as the coolant in the reactor chamber and the blanket concept must be slightly modified by providing steel tubes (HT-9) as guiding tubes for the coolant flow. A particular engineering problem to be solved are the ion beam focusing magnets, which have to extend rather closely up to the center of the reactor chamber. (orig.) [de

Studies of endothelial monolayer formation on irradiated poly-L-lactide acid with ions of different stopping power and velocity

International Nuclear Information System (INIS)

Arbeitman, Claudia R.; Grosso, Mariela F. del; Ibañez, Irene L.; Behar, Moni; Grasselli, Mariano; Bermúdez, Gerardo García

2015-01-01

In this work we study cell viability, proliferation and morphology of bovine aortic endothelial cells (BAEC) cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. In a previous study comparing ions beams with the same stopping power we observed an increase in cell density and a better cell morphology at higher ion velocities. In the present work we continued this study using heavy ions beam with different stopping power and ion velocities. To this end thin films of 50 μm thickness were irradiated with 2 MeV/u and 0.10 MeV/u ion beams provided the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The results suggest that a more dense and elongated cell shapes, similar to the BAEC cells on the internal surface of bovine aorta, was obtained for stopping power of 18.2–22.1 MeV cm 2 mg −1 and ion velocity of 2 MeV/u. On the other hand, for low ion velocity 0.10 MeV/u the cells present a more globular shapes.

The stopping powers and energy straggling of heavy ions in polymer foils

Energy Technology Data Exchange (ETDEWEB)

Mikšová, R., E-mail: miksova@ujf.cas.cz [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v.v.i., 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske Mladeze 8, 400 96 Usti nad Labem (Czech Republic); Macková, A.; Malinský, P. [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v.v.i., 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske Mladeze 8, 400 96 Usti nad Labem (Czech Republic); Hnatowicz, V. [Nuclear Physics Institute of the Academy of Sciences of the Czech Republic, v.v.i., 250 68 Rez (Czech Republic); Slepička, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2014-07-15

The stopping power and energy straggling of {sup 7}Li, {sup 12}C and {sup 16}O ions in thin poly(etheretherketone) (PEEK), polyethylene terephthalate (PET) and polycarbonate (PC) foils were measured in the incident beam energy range of 9.4–11.8 MeV using an indirect transmission method. Ions scattered from a thin gold target at an angle of 150° were registered by a partially depleted PIPS detector, partly shielded with a polymer foil placed in front of the detector. Therefore, the signals from both direct and slowed down ions were visible in the same energy spectrum, which was evaluated by the ITAP code, developed at our laboratory. The ITAP code was employed to perform a Gaussian-fitting procedure to provide a complete analysis of each measured spectrum. The measured stopping powers were compared with the predictions obtained from the SRIM-2008 and MSTAR codes and with previous experimental data. The energy straggling data were compared with those calculated by using Bohr’s, Lindhard–Scharff and Bethe–Livingston theories.

The stopping powers and energy straggling of heavy ions in polymer foils

International Nuclear Information System (INIS)

Mikšová, R.; Macková, A.; Malinský, P.; Hnatowicz, V.; Slepička, P.

2014-01-01

The stopping power and energy straggling of 7 Li, 12 C and 16 O ions in thin poly(etheretherketone) (PEEK), polyethylene terephthalate (PET) and polycarbonate (PC) foils were measured in the incident beam energy range of 9.4–11.8 MeV using an indirect transmission method. Ions scattered from a thin gold target at an angle of 150° were registered by a partially depleted PIPS detector, partly shielded with a polymer foil placed in front of the detector. Therefore, the signals from both direct and slowed down ions were visible in the same energy spectrum, which was evaluated by the ITAP code, developed at our laboratory. The ITAP code was employed to perform a Gaussian-fitting procedure to provide a complete analysis of each measured spectrum. The measured stopping powers were compared with the predictions obtained from the SRIM-2008 and MSTAR codes and with previous experimental data. The energy straggling data were compared with those calculated by using Bohr’s, Lindhard–Scharff and Bethe–Livingston theories

Research on the character and development of the neutral beam injector RF negative ion source

International Nuclear Information System (INIS)

Guan Liang

2011-01-01

The RF source is now an interesting alternative to the reference design with filamented sources due to its maintenance-free operation. Extensive R and D work on RF-driven negative hydrogen ion sources carried out at IPP Garching led to the decision of ITER to select this type of source as the new reference source for the ITER NBI system.The work is progressing with three test beds: BATMAN, MANITU and RADI, which are being used to carry out different investigations in parallel. The experimental results show that the RF source equals or surpasses the ITER requirements. (authors)

Simulation study of magnetically insulated power coupling to the applied-B ion diode

International Nuclear Information System (INIS)

Rosenthal, S.E.

1992-01-01

Power coupling to the applied-B ion diode from magnetically insulated transmission lines is simply described in terms of the voltage-current characteristics of both the diode and the transmission line. The accelerator load line intersects the composite characteristic at the operating voltage and current. Using 2-D PIC simulation, the authors have investigated how modification of either the ion diode or the magnetically insulated transmission line characteristic influences power coupling. Plasma prefill can modify the ion diode characteristic; a partially opened POS in the transmission line upstream of the ion diode is a possible cause of modification of the magnetically insulated transmission line characteristic. It can be useful to consider these two aspects of power coupling separately, but they are actually not independent. A good parameter to characterize the situation is the flow impedance, given by V/(I a 2 I c 2 ) 1/2 . V is the line voltage; I a and I c are the conduction currents flowing through the anode and cathode, respectively. The flow impedance covers a range from one half the vacuum impedance, for saturated magnetically insulated flow, to just below the vacuum impedance, for highly unsaturated flow. As the term ''flow impedance'' implies, low flow impedance coincides with greater electron flow while high flow impedance coincides with less electron flow. The flow impedance is sensitive to both the transmission line and the diode impedance. They show how the two are related, using the flow impedance as a parameter

Thermal management for high power lithium-ion battery by minichannel aluminum tubes

International Nuclear Information System (INIS)

Lan, Chuanjin; Xu, Jian; Qiao, Yu; Ma, Yanbao

2016-01-01

Highlights: • A new design of minichannel cooling is developed for battery thermal management system. • Parametric studies of minichannel cooling for a cell are conducted at different discharge rates. • Minichannel cooling can maintain almost uniform temperature (T_d_i_f_f < 1 °C). • Pumping power assumption is only about 5 milliwatt. - Abstract: Lithium-ion batteries are widely used for battery electric (all-electric) vehicles (BEV) and hybrid electric vehicles (HEV) due to their high energy and power density. An battery thermal management system (BTMS) is crucial for the performance, lifetime, and safety of lithium-ion batteries. In this paper, a novel design of BTMS based on aluminum minichannel tubes is developed and applied on a single prismatic Li-ion cell under different discharge rates. Parametric studies are conducted to investigate the performance of the BTMS using different flow rates and configurations. With minichannel cooling, the maximum cell temperature at a discharge rate of 1C is less than 27.8 °C, and the temperature difference across the cell is less than 0.80 °C using flow rate at 0.20 L/min, at the expense of 8.69e-6 W pumping power. At higher discharge rates, e.g., 1.5C and 2C, higher flow rates are required to maintain the same temperature rise and temperature difference. The flow rate needed is 0.8 L/min for 1.5C and 2.0 L/min for 2C, while the required pumping power is 4.23e-4 W and 5.27e-3 W, respectively. The uniform temperature distribution (<1 °C) inside the single cell and efficient pumping power demonstrate that the minichannel cooling system provides a promising solution for the BTMS.

Poloidal asymmetries of the heavy ions in the ASDEX Upgrade tokamak

Energy Technology Data Exchange (ETDEWEB)

Odstrcil, Tomas [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Physik-Department E28, Technische Universitaet Muenchen, Garching (Germany); Puetterich, Thomas; Angioni, Clemente; Bilato, Roberto; Gude, Anja; Vezinet, Didier [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Mazon, Didier [CEA, IRFM, Saint Paul-lez-Durance (France); Collaboration: ASDEX Upgrade Team

2015-05-01

Poloidal asymmetries of heavy ions in the tokamak plasma are caused by the presence of forces parallel with field-lines which have comparable magnitude to the thermal pressure. The most important examples are the centrifugal force (CF) and the electric force (EF). The CF is caused by fast toroidal rotation of the plasma column which is pushing impurity ions, that have a substantially higher mass than the main ions, on the outer-side of the plasma. And the EF can be produced by ion cyclotron heated fast particles with high pitch angle that are trapped by the mirror force on the low field side of the plasma. The excessive charge produced by these particles is affecting highly charged impurities and pushing them to the high field side of the plasma. From predictions based on neoclassical and turbulent theory, it follows that the radial flux of heavy ions will be significantly changed by the presence of these asymmetries. The purpose of this study is to investigate the presence of these asymmetries in ASDEX Upgrade and verify the predicted consequences on the particles flux. High intrinsic content of the tungsten in AUG plasma makes this device well suitable for such studies. Precise measurement of the SXR (soft-X-ray) radiation profiles has identified a presence of CF generated asymmetries in every NBI heated Asdex discharge. Poloidal asymmetry should than lead to the significant change in the neoclassical and turbulent radial transport of these heavy ions. High intrinsic content of the tungsten in Asdex plasma makes this device well suitable for studying these asymmetries. Precise measurement of the SXR (soft-X-ray) radiation profiles has identified a presence of CF generated asymmetries in every NBI heated Asdex discharge. For heavy and highly charged impurities multiple mechanisms exist that produce non-constant impurities densities on the flux surfaces. As for neoclassical and turbulent transport models such an asymmetry is of highly importance an effort is

Density profile effects on confinement and MHD stability of currentless NBI plasmas in Heliotron E

International Nuclear Information System (INIS)

Sudo, Shigeru; Zushi, Hideki; Kondo, Katsumi

1993-01-01

Density profile effects on confinement and MHD stability of currentless NBI plasmas in Heliotron E are studied. The peaked density profile produced by pellet injection increases the stored energy by 20-30% compared to the gas puffed plasmas which obey the empirical stellarator/heliotron scaling in a moderate density range. In contrast to confinement, the peaked pressure profile tends to destabilize the plasma. By limiter insertion, MHD instability occurs (seems to locate near ι/2π=1) even in case of low β (β 0 ≤1%, where β 0 is the central β value) plasmas. On the other hand, the mode of m/n=3/2 at ι/2π=2/3, seems to be a key parameter to the major MHD instability in case of high β (β 0 ≥2%) plasmas. (author)

The stopping power and energy straggling of heavy ions in silicon nitride and polypropylene

Energy Technology Data Exchange (ETDEWEB)

Mikšová, R., E-mail: miksova@ujf.cas.cz [Nuclear Physics Institute of the Academy of Science of the Czech Republic v.v. i., 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J. E. Purkinje University, Ceske Mladeze 8, 400 96 Usti nad Labem (Czech Republic); Hnatowicz, V. [Nuclear Physics Institute of the Academy of Science of the Czech Republic v.v. i., 250 68 Rez (Czech Republic); Macková, A.; Malinský, P. [Nuclear Physics Institute of the Academy of Science of the Czech Republic v.v. i., 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J. E. Purkinje University, Ceske Mladeze 8, 400 96 Usti nad Labem (Czech Republic); Slepička, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2015-07-01

The stopping power and energy straggling of {sup 12}C{sup 3+} and {sup 16}O{sup 3+} ions with energies between 4.5 and 7.8 MeV in a 0.166-μm-thin silicon nitride and in 4-μm-thin polypropylene foils were measured by means of an indirect transmission method using a half-covered PIPS detector. Ions scattered from a thin gold layer under a scattering angle of 150° were used. The energy spectra of back-scattered and decelerated ions were registered and evaluated simultaneously. The measured stopping powers were compared with the theoretical predictions simulated by SRIM-2008 and MSTAR codes. SRIM prediction of energy stopping is reasonably close to the experimentally obtained values comparing to MSTAR values. Better agreement between experimental and predicted data was observed for C{sup 3+} ion energy losses comparing to O{sup 3+} ions. The experimental data from Paul’s database and our previous experimental data were also discussed. The obtained experimental energy-straggling data were compared to those calculated by using Bohr’s, Yang’s models etc. The predictions by Yang are in good agreement with our experiment within a frame of uncertainty of 25%.

The stopping power and energy straggling of heavy ions in silicon nitride and polypropylene

International Nuclear Information System (INIS)

Mikšová, R.; Hnatowicz, V.; Macková, A.; Malinský, P.; Slepička, P.

2015-01-01

The stopping power and energy straggling of 12 C 3+ and 16 O 3+ ions with energies between 4.5 and 7.8 MeV in a 0.166-μm-thin silicon nitride and in 4-μm-thin polypropylene foils were measured by means of an indirect transmission method using a half-covered PIPS detector. Ions scattered from a thin gold layer under a scattering angle of 150° were used. The energy spectra of back-scattered and decelerated ions were registered and evaluated simultaneously. The measured stopping powers were compared with the theoretical predictions simulated by SRIM-2008 and MSTAR codes. SRIM prediction of energy stopping is reasonably close to the experimentally obtained values comparing to MSTAR values. Better agreement between experimental and predicted data was observed for C 3+ ion energy losses comparing to O 3+ ions. The experimental data from Paul’s database and our previous experimental data were also discussed. The obtained experimental energy-straggling data were compared to those calculated by using Bohr’s, Yang’s models etc. The predictions by Yang are in good agreement with our experiment within a frame of uncertainty of 25%

Reduced power processor requirements for the 30-cm diameter HG ion thruster

Science.gov (United States)

Rawlin, V. K.

1979-01-01

The characteristics of power processors strongly impact the overall performance and cost of electric propulsion systems. A program was initiated to evaluate simplifications of the thruster-power processor interface requirements. The power processor requirements are mission dependent with major differences arising for those missions which require a nearly constant thruster operating point (typical of geocentric and some inbound planetary missions) and those requiring operation over a large range of input power (such as outbound planetary missions). This paper describes the results of tests which have indicated that as many as seven of the twelve power supplies may be eliminated from the present Functional Model Power Processor used with 30-cm diameter Hg ion thrusters.

Stopping powers of havar for 1.6, 2.3 and 3.2 MeV/u heavy ions

Energy Technology Data Exchange (ETDEWEB)

Alanko, T. E-mail: tommi.alanko@phys.jyu.fi; Hyvoenen, J.; Kylloenen, V.; Raeisaenen, J.; Virtanen, A

2000-03-01

Stopping powers of havar for {sup 28,30}Si-, {sup 36}Ar-, {sup 54,56}Fe- and {sup 80,84}Kr-ions with energies of 1.6, 2.3 and 3.2 MeV/u have been determined by a transmission technique. Sample foils are exposed to the direct beams. No previous data for havar with these ions have been published. The obtained results are brought together with literature havar data for {sup 1}H-, {sup 4}He-, {sup 7}Li-, {sup 11}B-, {sup 12}C-, {sup 14}N-, {sup 16}O- and {sup 127}I-ions at the same ion velocity. The experimental data are compared with the values predicted by the SRIM-2000 parametrization using Bragg's rule. A systematic underestimation, by 6-23%, of the experimental stopping powers was observed. The empirical correction scheme of Thwaites has been applied to the stopping power values obtained by the parametrization. The corrected values agree well with the present results. Also, the effective charge values of the various ions were deduced from the experimental set of data.

Kinetic equilibrium reconstruction for the NBI- and ICRH-heated H-mode plasma on EAST tokamak

Science.gov (United States)

Zhen, ZHENG; Nong, XIANG; Jiale, CHEN; Siye, DING; Hongfei, DU; Guoqiang, LI; Yifeng, WANG; Haiqing, LIU; Yingying, LI; Bo, LYU; Qing, ZANG

2018-04-01

The equilibrium reconstruction is important to study the tokamak plasma physical processes. To analyze the contribution of fast ions to the equilibrium, the kinetic equilibria at two time-slices in a typical H-mode discharge with different auxiliary heatings are reconstructed by using magnetic diagnostics, kinetic diagnostics and TRANSP code. It is found that the fast-ion pressure might be up to one-third of the plasma pressure and the contribution is mainly in the core plasma due to the neutral beam injection power is primarily deposited in the core region. The fast-ion current contributes mainly in the core region while contributes little to the pedestal current. A steep pressure gradient in the pedestal is observed which gives rise to a strong edge current. It is proved that the fast ion effects cannot be ignored and should be considered in the future study of EAST.

Supersonic plasma beams with controlled speed generated by the alternative low power hybrid ion engine (ALPHIE) for space propulsion

Science.gov (United States)

Conde, L.; Domenech-Garret, J. L.; Donoso, J. M.; Damba, J.; Tierno, S. P.; Alamillo-Gamboa, E.; Castillo, M. A.

2017-12-01

The characteristics of supersonic ion beams from the alternative low power hybrid ion engine (ALPHIE) are discussed. This simple concept of a DC powered plasma accelerator that only needs one electron source for both neutral gas ionization and ion beam neutralization is also examined. The plasma production and space charge neutralization processes are thus coupled in this plasma thruster that has a total DC power consumption of below 450 W, and uses xenon or argon gas as a propellant. The operation parameters of the plasma engine are studied in the laboratory in connection with the ion energy distribution function obtained with a retarding-field energy analyzer. The ALPHIE plasma beam expansion produces a mesothermal plasma flow with two-peaked ion energy distribution functions composed of low and high speed ion groups. The characteristic drift velocities of the fast ion groups, in the range 36.6-43.5 Km/s, are controlled by the acceleration voltage. These supersonic speeds are higher than the typical ion sound velocities of the low energy ion group produced by the expansion of the plasma jet. The temperatures of the slow ion population lead to ion Debye lengths longer than the electron Debye lengths. Furthermore, the electron impact ionization can coexist with collisional ionization by fast ions downstream the grids. Finally, the performance characteristics and comparisons with other plasma accelerator schemes are also discussed.

Automated system for efficient microwave power coupling in an S-band ECR ion source driven under different operating conditions

Energy Technology Data Exchange (ETDEWEB)

Muguira, L., E-mail: lmuguira@essbilbao.org [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain); Portilla, J. [University of Basque Country (UPV/EHU), Department of Electricity and Electronics, Science and Technology Faculty, 48940 Leioa (Bizkaia) (Spain); Gonzalez, P.J.; Garmendia, N.; Feuchtwanger, J. [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain); Etxebarria, V. [University of Basque Country (UPV/EHU), Department of Electricity and Electronics, Science and Technology Faculty, 48940 Leioa (Bizkaia) (Spain); Eguiraun, M.; Arredondo, I.; Miracoli, R.; Belver, D. [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain)

2014-03-21

This article presents an automated system for optimizing the microwave power coupling to the plasma generated in a proton/deuteron Electron Cyclotron Resonance (ECR) source, based on a specific model of a rectangular waveguide triple-stub tuner and the integrated measurement and control electronics, helping to get stable plasma states. The control and improvement of the RF power absorption into the plasma is a complex process, essential for the ion source development and optimization under different operating conditions. A model and a matching algorithm for the triple-stub tuner have been developed and, besides, different methods to accurately measure the power transfer in a waveguide RF system have been studied and deployed in the ESS-Bilbao ion source system. The different parts have been integrated through a controller, which allows to run an automatic plasma matching system in closed loop. The behavior of the system implemented for low and high power regimes has been tested under different conditions: with several load impedances, with plasma inside the chamber, in continuous wave and pulsed wave operation modes, demonstrating power absorption typically over 90% in all the ion source configurations. The developed system allows to achieve significant improvement in the ECR ion source power absorption efficiency, both in continuous and pulsed mode. The automatic tuning unit enhances the system operation finding an optimum solution much faster than manually, also behaving as an adaptive system able to respond in few pulses to ion source configuration changes to maintain the power coupling as high as possible. - Highlights: • An automated system optimizing plasma and microwave power interaction is presented. • A model and a matching algorithm for the triple-stub tuner have been developed. • Different methods to measure the power transfer have been studied and deployed. • The system works for low or high power regimes under different ion source conditions. �

Automated system for efficient microwave power coupling in an S-band ECR ion source driven under different operating conditions

International Nuclear Information System (INIS)

Muguira, L.; Portilla, J.; Gonzalez, P.J.; Garmendia, N.; Feuchtwanger, J.; Etxebarria, V.; Eguiraun, M.; Arredondo, I.; Miracoli, R.; Belver, D.

2014-01-01

This article presents an automated system for optimizing the microwave power coupling to the plasma generated in a proton/deuteron Electron Cyclotron Resonance (ECR) source, based on a specific model of a rectangular waveguide triple-stub tuner and the integrated measurement and control electronics, helping to get stable plasma states. The control and improvement of the RF power absorption into the plasma is a complex process, essential for the ion source development and optimization under different operating conditions. A model and a matching algorithm for the triple-stub tuner have been developed and, besides, different methods to accurately measure the power transfer in a waveguide RF system have been studied and deployed in the ESS-Bilbao ion source system. The different parts have been integrated through a controller, which allows to run an automatic plasma matching system in closed loop. The behavior of the system implemented for low and high power regimes has been tested under different conditions: with several load impedances, with plasma inside the chamber, in continuous wave and pulsed wave operation modes, demonstrating power absorption typically over 90% in all the ion source configurations. The developed system allows to achieve significant improvement in the ECR ion source power absorption efficiency, both in continuous and pulsed mode. The automatic tuning unit enhances the system operation finding an optimum solution much faster than manually, also behaving as an adaptive system able to respond in few pulses to ion source configuration changes to maintain the power coupling as high as possible. - Highlights: • An automated system optimizing plasma and microwave power interaction is presented. • A model and a matching algorithm for the triple-stub tuner have been developed. • Different methods to measure the power transfer have been studied and deployed. • The system works for low or high power regimes under different ion source conditions. �

Power dependence of ion thermal diffusivity at the internal transport barrier in JT-60U

Energy Technology Data Exchange (ETDEWEB)

Sakamoto, Yoshiteru; Suzuki, Takahiro; Ide, Shunsuke [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

2002-09-01

The formation properties of an internal transport barrier (ITB) were investigated in a weak positive magnetic shear plasma by changing the neutral beam heating power. The ion thermal diffusivity in the core region shows L-mode state, weak ITB, and strong ITB, depending upon the heating power. Two features of ITB formation were experimentally confirmed. Weak ITB was formed in spite of the absence of an apparent transition in an ion temperature profile. On the other hand, strong ITB appeared after an apparent transition from the weak ITB. In addition, the ion thermal diffusivity at the ITB is correlated to the radial electric field shear. In the case of the weak ITB, ion thermal diffusivity decreased gradually with increases in the radial electric field shear. There exists a threshold in the radial electric field shear, which allows for a change in state from that of weak to strong ITBs. (author)

Generation of net electric power with a tokamak reactor under foreseeable physical and engineering conditions

International Nuclear Information System (INIS)

Hiwatari, R.; Asaoka, Y.; Okano, K.; Yoshida, T.; Tomabechi, K.

2004-01-01

This study reveals for the first time the plasma performance required for a tokamak reactor to generate net electric power under foreseeable engineering conditions. It was found that the reference plasma performance of the ITER inductive operation mode with β N = 1.8, HH = 1.0, andf nGW 0.85 had sufficient potential to achieve the electric break-even condition (net electric power P e net = 0MW) under the following engineering conditions: machine major radius 6.5m ≤ R p ≤ 8.5m, the maximum magnetic field on TF coils B tmax = 16 T, thermal efficiency η e 30%, and NBI system efficiency η NBI = 50%. The key parameters used in demonstrating net electric power generation in tokamak reactors are β N and fη GW . ≥ 3.0 is required for P e net ∼ 600MW with fusion power P f ∼ 3000MW. On the other hand, fη GW ≥ 1.0 is inevitable to demonstrate net electric power generation, if high temperatures, such as average temperatures of T ave > 16 keV, cannot be selected for the reactor design. To apply these results to the design of a tokamak reactor for demonstrating net electric power generation, the plasma performance diagrams on the Q vs P f (energy multiplication factor vs fusion power) space for several major radii (i.e. 6.5, 7.5, and 8.5 m) were depicted. From these figures, we see that a design with a major radius R p ∼ 7.5m seems preferable for demonstrating net electric power generation when one aims at early realization of fusion energy. (author)

Experiments on Li pellet injection into Heliotron E

International Nuclear Information System (INIS)

Sergeev, V.Yu.; Khlopenkov, K.V.; Kuteev, B.V.; Sudo, S.; Kondo, K.; Zushi, H.; Besshou, S.; Sano, F.; Okada, H.; Mizuuchi, T.; Nagasaki, K.; Obiki, T.; Kurimoto, Y.

1998-01-01

Li pellets of large size were injected into electron cyclotron resonance (ECR) heated plasmas and neutral beam injection (NBI) heated plasmas of Heliotron E. The discharge behaviour, pellet ablation and wall conditioning were studied. The electron pressure is doubled after injection into the NBI plasma and remains unchanged in the case of ECR heating. This may be due to the energy exchange between the electrons and thermal ions with the fast ions from the neutral beam. The observed discrepancy between the experimental and modelled ablation rates may be caused by both the plasma cooling due to pellet ablatant and the ablation stimulated by the fast ions in the NBI-heated regime and by the fast electrons in the ECR-heated regime. In preliminary experiments on wall conditioning by Li pellet injection, no improvement of plasma performance after Li pellet injection was observed in the divertor or limiter configuration, with the limiter radii r L =24-25cm. (author)

Studies of endothelial monolayer formation on irradiated poly-L-lactide acid with ions of different stopping power and velocity

Energy Technology Data Exchange (ETDEWEB)

Arbeitman, Claudia R. [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina); UNQ – IMBICE – CCT – CONICET – LA PLATA (Argentina); Grosso, Mariela F. del [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina); Ibañez, Irene L. [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Behar, Moni [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Grasselli, Mariano [UNQ – IMBICE – CCT – CONICET – LA PLATA (Argentina); Bermúdez, Gerardo García [Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina)

2015-12-15

In this work we study cell viability, proliferation and morphology of bovine aortic endothelial cells (BAEC) cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. In a previous study comparing ions beams with the same stopping power we observed an increase in cell density and a better cell morphology at higher ion velocities. In the present work we continued this study using heavy ions beam with different stopping power and ion velocities. To this end thin films of 50 μm thickness were irradiated with 2 MeV/u and 0.10 MeV/u ion beams provided the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The results suggest that a more dense and elongated cell shapes, similar to the BAEC cells on the internal surface of bovine aorta, was obtained for stopping power of 18.2–22.1 MeV cm{sup 2} mg{sup −1} and ion velocity of 2 MeV/u. On the other hand, for low ion velocity 0.10 MeV/u the cells present a more globular shapes.

Nanomaterials Enabled High Energy and Power Density Li-ion Batteries, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — There is a need for high energy (~ 200 Wh/kg) and high power (> 500 W/kg) density rechargeable Li-ion batteries that are safe and reliable for several space and...

Measurement of stopping powers of gases for heavy ions of 3 to 13 MeV by nucleon

International Nuclear Information System (INIS)

Orliange, I.

1985-09-01

The stopping powers of gases have been measured for incident 10 Ne, 18 Ar, 29 Cu, 36 Kr and 47 Ag ions of 3 to 13 MeV/u. These measurements have confirmed the existence of a gas-solid difference for the stopping powers (the stopping power of solids being larger than that of gazes). Such a difference was theoretically postulated by Bohr and Lindhard in 1954, and experimentally observed for the first time by Geissel in 1982. This effect can be qualitatively interpreted by a difference in the ion's effective charge in stopping power. However, the determination of charge state distribution for Ar and Fe ions in two particular cases (Ar + Nsub(2s)or Nsub(2g) and (Fe + Csub(s) or Csub(g)) from a theoric model and experimental cross sections for atomic collisions don't quantitatively account for observed differences [fr

Adaptive on-line prediction of the available power of lithium-ion batteries

Science.gov (United States)

Waag, Wladislaw; Fleischer, Christian; Sauer, Dirk Uwe

2013-11-01

In this paper a new approach for prediction of the available power of a lithium-ion battery pack is presented. It is based on a nonlinear battery model that includes current dependency of the battery resistance. It results in an accurate power prediction not only at room temperature, but also at lower temperatures at which the current dependency is substantial. The used model parameters are fully adaptable on-line to the given state of the battery (state of charge, state of health, temperature). This on-line adaption in combination with an explicit consideration of differences between characteristics of individual cells in a battery pack ensures an accurate power prediction under all possible conditions. The proposed trade-off between the number of used cell parameters and the total accuracy as well as the optimized algorithm results in a real-time capability of the method, which is demonstrated on a low-cost 16 bit microcontroller. The verification tests performed on a software-in-the-loop test bench system with four 40 Ah lithium-ion cells show promising results.

Neutral beam injection system design for KSTAR tokamak

Energy Technology Data Exchange (ETDEWEB)

Choi, B.H.; Lee, K.W.; Chung, K.S.; Oh, B.H.; Cho, Y.S.; Bae, Y.D.; Han, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea)

1998-06-01

The NBI system for KSTAR (Korean Superconducting Tokamak Advanced Research) has been designed based on conventional positive ion beam technology. One beam line consists of three ion sources, three neutralizers, one bending magnet, and one drift tube. This system will deliver 8 MW deuterium beam to KSTAR plasma in normal operation to support the advanced experiments on heating, current drive and profile control. The key technical issues in this design were high power ion source(120 kV, 65 A), long pulse operation (300 seconds; world record is 30 sec), and beam rotation from vertical to horizontal direction. The suggested important R and D points on ion source and beam line components are also included. (author). 7 refs., 27 figs., 1 tab.

A new digital pulse power supply in heavy ion research facility in Lanzhou

Science.gov (United States)

Wang, Rongkun; Chen, Youxin; Huang, Yuzhen; Gao, Daqing; Zhou, Zhongzu; Yan, Huaihai; Zhao, Jiang; Shi, Chunfeng; Wu, Fengjun; Yan, Hongbin; Xia, Jiawen; Yuan, Youjin

2013-11-01

To meet the increasing requirements of the Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring (HIRFL-CSR), a new digital pulse power supply, which employs multi-level converter, was designed. This power supply was applied with a multi H-bridge converters series-parallel connection topology. A new control model named digital power supply regulator system (DPSRS) was proposed, and a pulse power supply prototype based on DPSRS has been built and tested. The experimental results indicate that tracking error and ripple current meet the requirements of this design. The achievement of prototype provides a perfect model for HIRFL-CSR power supply system.

JET neutral beam duct Optical Interlock

Energy Technology Data Exchange (ETDEWEB)

Ash, A.D.; Jones, T.T.C.; Surrey, E.; Ćirić, D.; Hall, S.I.; Young, D.; Afzal, M.; Hackett, L.; Day, I.E.; King, R.

2015-10-15

Highlights: • Optical Interlocks were installed on the JET NBI system as part of the EP2 upgrade. • The system protects the JET tokamak and NBI systems from thermal load damage. • Balmer-α beam emission is used to monitor the neutral beam-line pressure. • We demonstrate an improved trip delay of 2 ms compared to 50 ms before EP2. - Abstract: The JET Neutral Beam Injection (NBI) system is the most powerful neutral beam plasma heating system currently operating. Optical Interlocks were installed on the beam lines in 2011 for the JET Enhancement Project 2 (EP2), when the heating power was increased from 23 MW to 34 MW. JET NBI has two beam lines. Each has eight positive ion injectors operating in deuterium at 80 kV–125 kV (accelerator voltage) and up to 65 A (beam current). Heating power is delivered through two ducts where the central power density can be more than 100 MW/m{sup 2}. In order to deliver this safely, the beam line pressure should be below 2 × 10{sup −5} mbar otherwise the power load on the duct from the re-ionised fraction of the beam is excessive. The new Optical Interlock monitors the duct pressure by measuring the Balmer-α beam emission (656 nm). This is proportional to the instantaneous beam flux and the duct pressure. Light is collected from a diagnostic window and focused into 1-mm diameter fibres. The Doppler shifted signal is selected using an angle-tuned interference filter. The light is measured by a photo-multiplier module with a logarithmic amplifier. The interlock activation time of 2 ms is sufficient to protect the system from a fully re-ionised beam—a significant improvement on the previous interlock. The dynamic range is sufficient to see bremsstrahlung emission from JET plasma and not saturate during plasma disruptions. For high neutron flux operations the optical fibres within the biological shield can be annealed to 350 °C. A self-test is possible by illuminating the diagnostic window with a test lamp and measuring

Double null X-point operation in JET with NBI and ICRH heating

International Nuclear Information System (INIS)

Tubbing, B.; Bhatnagar, V.

1989-01-01

In this paper we report on a selection of experiments on H-modes, in 3 and 3.5MA discharges, in the double null X-point configuration. The first experiment, section 2, is an attempt to couple ICRH power to H-modes. Here we also report on a rather unique H-mode with a smaller than usual distance between plasma and limiter. The second experiment, section 3, is on H-modes in the low density, hot ion regime. (author) 5 refs., 4 figs

Improvement of ionizer and power supply of 860 A sputtering negative ion source

International Nuclear Information System (INIS)

An Kun; Yu Lingda; Wu Bingbing; Wang Guangfu

2014-01-01

A transmission surface type ionizer was developed with a φ2.5 mm stainless steel sheath core heating cable, and the ion source power supply was also improved. A continuous adjustable DC switching power supply was employed instead of the original AC power supply as the ionizer power supply, and a 0 - -20 kV DC power supply at the ground potential as the power of the immersion lens replaced the original 10 kV DC power supply suspended in -20 kV. The variation of the beam intensity of H"- in the front Faraday cup of the GIC4117 2 × 1.7 MV tandetron with the ionizer heating current was also shown. (authors)

Fast wave current drive in neutral beam heated plasmas on DIII-D

International Nuclear Information System (INIS)

Petty, C.C.; Forest, C.B.; Pinsker, R.I.

1997-04-01

The physics of non-inductive current drive and current profile control using the fast magnetosonic wave has been demonstrated on the DIII-D tokamak. In non-sawtoothing discharges formed by neutral beam injection (NBI), the radial profile of the fast wave current drive (FWCD) was determined by the response of the loop voltage profile to co, counter, and symmetric antenna phasings, and was found to be in good agreement with theoretical models. The application of counter FWCD increased the magnetic shear reversal of the plasma and delayed the onset of sawteeth, compared to co FWCD. The partial absorption of fast waves by energetic beam ions at high harmonics of the ion cyclotron frequency was also evident from a build up of fast particle pressure near the magnetic axis and a correlated increase in the neutron rate. The anomalous fast particle pressure and neutron rate increased with increasing NBI power and peaked when a harmonic of the deuterium cyclotron frequency passed through the center of the plasma. The experimental FWCD efficiency was highest at 2 T where the interaction between the fast waves and the beam ions was weakest; as the magnetic field strength was lowered, the FWCD efficiency decreased to approximately half of the maximum theoretical value

An area and power-efficient analog li-ion battery charger circuit.

Science.gov (United States)

Do Valle, Bruno; Wentz, Christian T; Sarpeshkar, Rahul

2011-04-01

The demand for greater battery life in low-power consumer electronics and implantable medical devices presents a need for improved energy efficiency in the management of small rechargeable cells. This paper describes an ultra-compact analog lithium-ion (Li-ion) battery charger with high energy efficiency. The charger presented here utilizes the tanh basis function of a subthreshold operational transconductance amplifier to smoothly transition between constant-current and constant-voltage charging regimes without the need for additional area- and power-consuming control circuitry. Current-domain circuitry for end-of-charge detection negates the need for precision-sense resistors in either the charging path or control loop. We show theoretically and experimentally that the low-frequency pole-zero nature of most battery impedances leads to inherent stability of the analog control loop. The circuit was fabricated in an AMI 0.5-μm complementary metal-oxide semiconductor process, and achieves 89.7% average power efficiency and an end voltage accuracy of 99.9% relative to the desired target 4.2 V, while consuming 0.16 mm(2) of chip area. To date and to the best of our knowledge, this design represents the most area-efficient and most energy-efficient battery charger circuit reported in the literature.

Predictive study on high performance modes of operation in HL-2A

International Nuclear Information System (INIS)

Gao Qingdi; Li Fangzhu; Zhang Jinhua; Qu Hongpeng; Budny, R.V.

2003-01-01

High performance scenarios in the HL-2A tokamak are studied by numerical modeling. Through shifting the plasma column outwards a shaping plasma with significant triangularity is achieved with sufficient room left for the RF antenna. For the out-shifted shaping plasma, ripple loss of high energy ions during NBI is analyzed. The results show that the ripple loss fraction of NBI power for the shaping plasma is not higher than that for the unshifted circular plasma. The time dependent TRANSP code is used to model realistic reversed magnetic shear operation in HL-2A. In order to sustain the RS operation towards steady-state, off-axis current drive with a lower hybrid wave at 2.45GHz is used to control the current profile. A steady-state RS discharge is formed and sustained until the LH power is turned off; the plasma confinement is enhanced with the development of an internal transport barrier. In the RS discharges with shaping plasma geometry a double transport barrier is produced. (author)

Stopping power and range relations for low and high Z ions in solids: a critical analysis

International Nuclear Information System (INIS)

Virk, H.S.; Randhawa, G.S.

1997-01-01

A critical analysis of various stopping power and range formulations has been made by comparing the calculated stopping power and range values with corresponding experimental values for different low Z (1≤Z≤8) and high Z projectiles (54≤Z≤92) in different targets, e.g. Be, C, Al, Au, Pb, CR-39, Lexan, Mylar, LR-115, CH, (CH)n, TRIFOL-TN, etc. atvarious low and high energies. A comparative study has been made by taking into consideration different target and projectile combinations, e.g., heavy ion-light target, light ion-heavy target and light ion -light target etc., Overall the Ziegler formulation (TRIM-95) provides the best agreement with the experimental results for all projectile and target combinations except for heavy ion-light target combination where it underestimates the stopping power data and overestimates the range data in the range, 2-50 MeV/u. Mukherjee and Nayak formulation totally fails at relativistic and low energies of the projectile, irrespective of the projectile-target combination. Northcliffe and Schilling formulation does not show any particular trend. Benton and Henke formulation gives good agreement between experimental and theoretical data within the range of experimental errors. (orig.)

Preparation of All-Ceramic, High Performance Li-ion Batteries for Deep Space Power Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Lithium (Li) ion batteries are among the most promising power sources for many civilian, military and space applications due to their high power and high energy...

Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

International Nuclear Information System (INIS)

Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

1998-01-01

Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots (∼100 (micro)m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with ρr ∼ 2 g/cm 2 for a small demo/pilot plant producing ∼40 MJ of fusion yield per target, and (2) a large target with ρr ∼ 10 g/cm 2 producing ∼1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q ∼ 26) ion sources for short (∼5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of ∼10 MG fields to provide steep focusing angles close-in to the target (built-in as part of each target); (4) beam space charge

Ion-driver fast ignition: Reducing heavy-ion fusion driver energy and cost, simplifying chamber design, target fab, tritium fueling and power conversion

Energy Technology Data Exchange (ETDEWEB)

Logan, G.; Callahan-Miller, D.; Perkins, J.; Caporaso, G.; Tabak, M.; Moir, R.; Meier, W.; Bangerter, Roger; Lee, Ed

1998-04-01

Ion fast ignition, like laser fast ignition, can potentially reduce driver energy for high target gain by an order of magnitude, while reducing fuel capsule implosion velocity, convergence ratio, and required precisions in target fabrication and illumination symmetry, all of which should further improve and simplify IFE power plants. From fast-ignition target requirements, we determine requirements for ion beam acceleration, pulse-compression, and final focus for advanced accelerators that must be developed for much shorter pulses and higher voltage gradients than today's accelerators, to deliver the petawatt peak powers and small focal spots ({approx}100 {micro}m) required. Although such peak powers and small focal spots are available today with lasers, development of such advanced accelerators is motivated by the greater likely efficiency of deep ion penetration and deposition into pre-compressed 1000x liquid density DT cores. Ion ignitor beam parameters for acceleration, pulse compression, and final focus are estimated for two examples based on a Dielectric Wall Accelerator; (1) a small target with {rho}r {approx} 2 g/cm{sup 2} for a small demo/pilot plant producing {approx}40 MJ of fusion yield per target, and (2) a large target with {rho}r {approx} 10 g/cm{sup 2} producing {approx}1 GJ yield for multi-unit electricity/hydrogen plants, allowing internal T-breeding with low T/D ratios, >75 % of the total fusion yield captured for plasma direct conversion, and simple liquid-protected chambers with gravity clearing. Key enabling development needs for ion fast ignition are found to be (1) ''Close-coupled'' target designs for single-ended illumination of both compressor and ignitor beams; (2) Development of high gradient (>25 MV/m) linacs with high charge-state (q {approx} 26) ion sources for short ({approx}5 ns) accelerator output pulses; (3) Small mm-scale laser-driven plasma lens of {approx}10 MG fields to provide steep focusing angles

High-thrust and low-power operation of a 30-cm-diameter mercury ion thruster

Science.gov (United States)

Beattie, J. R.; Kami, S.

1981-01-01

An investigation of a 30-cm-diameter mercury ion thruster designed for high-thrust and low-power operation is described. Experimental results are presented which indicate that good performance and long lifetime are achieved by using a boundary magnetic field arrangement to confine the ionizing electrons. Details of advanced ion-optics designs are discussed, and performance measurements obtained with an advanced two-grid ion-optics assembly are presented. Scaling of the state-of-the-art hollow cathode for higher emission-current capability is described, and performance and lifetime measurements are presented for the scaled cathode.

A high energy and power sodium-ion hybrid capacitor based on nitrogen-doped hollow carbon nanowires anode

Science.gov (United States)

Li, Dongdong; Ye, Chao; Chen, Xinzhi; Wang, Suqing; Wang, Haihui

2018-04-01

The sodium ion hybrid capacitor (SHC) has been attracting much attention. However, the SHC's power density is significantly confined to a low level due to the sluggish ion diffusion in the anode. Herein, we propose to use an electrode with a high double layer capacitance as the anode in the SHC instead of insertion anodes. To this aim, nitrogen doped hollow carbon nanowires (N-HCNWs) with a high specific surface area are prepared, and the high capacitive contribution during the sodium ion storage process is confirmed by a series of electrochemical measurements. A new SHC consisting of a N-HCNW anode and a commercial active carbon (AC) cathode is fabricated for the first time. Due to the hybrid charge storage mechanism combining ion insertion and capacitive process, the as-fabricated SHC strikes a balance between the energy density and power density, a energy density of 108 Wh kg-1 and a power density of 9 kW kg-1 can be achieved, which overwhelms the electrochemical performances of most reported AC-based SHCs.

Accelerated Lifetime Testing Methodology for Lifetime Estimation of Lithium-ion Batteries used in Augmented Wind Power Plants

DEFF Research Database (Denmark)

Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina

2014-01-01

The development of lifetime estimation models for Lithium-ion battery cells, which are working under highly variable mission profiles characteristic for wind power plant applications, requires a lot of expenditures and time resources. Therefore, batteries have to be tested under accelerated...... lifetime ageing conditions. This paper presents a three-stage methodology used for accelerated lifetime testing of Lithium ion batteries. The results obtained at the end of the accelerated ageing process were used for the parametrization of a performance-degradation lifetime model, which is able to predict...... both the capacity fade and the power capability decrease of the selected Lithium-ion battery cells. In the proposed methodology both calendar and cycling lifetime tests were considered since both components are influencing the lifetime of Lithium-ion batteries. Furthermore, the proposed methodology...

Sawtooth stability in neutral beam heated plasmas in TEXTOR

NARCIS (Netherlands)

Chapman, I.T.; Pinches, S. D.; Koslowski, H. R.; Liang, Y.; Kramer-Flecken, A.; De Bock, M.

2008-01-01

The experimental sawtooth behaviour in neutral beam injection (NBI) heated plasmas in TEXTOR is described. It is found that the sawtooth period is minimized with a low NBI power oriented in the same direction as the plasma current. As the beam power is increased in the opposite direction to the

Specific power reduction of an ion source due to heating and cathode sputtering of electrodes

International Nuclear Information System (INIS)

Hamilton, G.U.; Semashko, N.N.

The potentialities and limitations of the water-cooled ion-optical system of the ion source designed for continuous operation of the high-power neutral beam injector are determined. The following problems are analyzed: thermal expansion and deformation of electrodes, electrode sputtering as a result of bombardment, and heat transfer to turbulent flow of water

Development of an energy analyzer as diagnostic of beam-generated plasma in negative ion beam systems

Science.gov (United States)

Sartori, E.; Carozzi, G.; Veltri, P.; Spolaore, M.; Cavazzana, R.; Antoni, V.; Serianni, G.

2017-08-01

The measurement of the plasma potential and the energy spectrum of secondary particles in the drift region of a negative ion beam offers an insight into beam-induced plasma formation and beam transport in low pressure gasses. Plasma formation in negative-ion beam systems, and the characteristics of such a plasma are of interest especially for space charge compensation, plasma formation in neutralizers, and the development of improved schemes of beam-induced plasma neutralisers for future fusion devices. All these aspects have direct implications in the ITER Heating Neutral Beam and the operation of the prototypes, SPIDER and MITICA, and also have important role in the conceptual studies for NBI systems of DEMO, while at present experimental data are lacking. In this paper we present the design and development of an ion energy analyzer to measure the beam plasma formation and space charge compensation in negative ion beams. The diagnostic is a retarding field energy analyzer (RFEA), and will measure the transverse energy spectra of plasma molecular ions. The calculations that supported the design are reported, and a method to interpret the measurements in negative ion beam systems is also proposed. Finally, the experimental results of the first test in a magnetron plasma are presented.

Achieving High-Energy-High-Power Density in a Flexible Quasi-Solid-State Sodium Ion Capacitor.

Science.gov (United States)

Li, Hongsen; Peng, Lele; Zhu, Yue; Zhang, Xiaogang; Yu, Guihua

2016-09-14

Simultaneous integration of high-energy output with high-power delivery is a major challenge for electrochemical energy storage systems, limiting dual fine attributes on a device. We introduce a quasi-solid-state sodium ion capacitor (NIC) based on a battery type urchin-like Na2Ti3O7 anode and a capacitor type peanut shell derived carbon cathode, using a sodium ion conducting gel polymer as electrolyte, achieving high-energy-high-power characteristics in solid state. Energy densities can reach 111.2 Wh kg(-1) at power density of 800 W kg(-1), and 33.2 Wh kg(-1) at power density of 11200 W kg(-1), which are among the best reported state-of-the-art NICs. The designed device also exhibits long-term cycling stability over 3000 cycles with capacity retention ∼86%. Furthermore, we demonstrate the assembly of a highly flexible quasi-solid-state NIC and it shows no obvious capacity loss under different bending conditions.

The IAEA stopping power database, following the trends in stopping power of ions in matter

Science.gov (United States)

Montanari, C. C.; Dimitriou, P.

2017-10-01

The aim of this work is to present an overview of the state of art of the energy loss of ions in matter, based on the new developments in the stopping power database of the International Atomic Energy Agency (IAEA). This exhaustive collection of experimental data, graphs, programs and comparisons, is the legacy of Helmut Paul, who made it accessible to the global scientific community, and has been extensively employed in theoretical and experimental research during the last 25 years. The field of stopping power in matter is evolving, with new trends in materials of interest, including oxides, nitrides, polymers, and biological targets. Our goal is to identify areas of interest and emerging data needs to meet the requirements of a continuously developing user community.

Patterned ion exchange membranes for improved power production in microbial reverse-electrodialysis cells

KAUST Repository

Liu, Jia; Geise, Geoffrey M.; Luo, Xi; Hou, Huijie; Zhang, Fang; Feng, Yujie; Hickner, Michael A.; Logan, Bruce E.

2014-01-01

Power production in microbial reverse-electrodialysis cells (MRCs) can be limited by the internal resistance of the reverse electrodialysis stack. Typical MRC stacks use non-conductive spacers that block ion transport by the so-called spacer shadow

Schenkel circuit and its characteristics. DC power source for NHV ion accelerator

Energy Technology Data Exchange (ETDEWEB)

Kimura, Toshio; Yamada, Masahiro; Nakazawa, Makoto; Iwamoto, Eiji [Nissin - High Voltage Co. Ltd., Kyoto (Japan)

1996-12-01

For DC high voltage source, it is necessary to have sufficient power capacity to suit for electric current capacity required for operational load and further sufficient power stability when adapting it to an ion accelerator. In this paper, outlines of various DC high voltage forming circuits using generally and characteristics of Schenkel type DC source adapted to ion accelerator were described. Characteristics of the NHV Schenkel type DC electric source on actual circuit construction is shown as follows; (1) Whole circuit construction is intended to improve its discharge resistance by assembly with gaps and resistors. (2) Stability caused by geometric shape specific to the Schenkel circuit is improved by adopting integral moldings of aluminum for its structural material. And, (3) Upgrading of cooling effect, and miniaturization and forming heat loss reduction of system are intended by adopting all aluminum to increasing pressure transformer storing tank for countermeasure of vortex current. (G.K.)

Schenkel circuit and its characteristics. DC power source for NHV ion accelerator

International Nuclear Information System (INIS)

Kimura, Toshio; Yamada, Masahiro; Nakazawa, Makoto; Iwamoto, Eiji

1996-01-01

For DC high voltage source, it is necessary to have sufficient power capacity to suit for electric current capacity required for operational load and further sufficient power stability when adapting it to an ion accelerator. In this paper, outlines of various DC high voltage forming circuits using generally and characteristics of Schenkel type DC source adapted to ion accelerator were described. Characteristics of the NHV Schenkel type DC electric source on actual circuit construction is shown as follows; 1) Whole circuit construction is intended to improve its discharge resistance by assembly with gaps and resistors. 2) Stability caused by geometric shape specific to the Schenkel circuit is improved by adopting integral moldings of aluminum for its structural material. And, 3) Upgrading of cooling effect, and miniaturization and forming heat loss reduction of system are intended by adopting all aluminum to increasing pressure transformer storing tank for countermeasure of vortex current. (G.K.)

Low-power, miniature {sup 171}Yb ion clock using an ultra-small vacuum package

Energy Technology Data Exchange (ETDEWEB)

Jau, Y.-Y.; Schwindt, P. D. D. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Partner, H. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Center for Quantum Information and Control (CQuIC), Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Prestage, J. D.; Kellogg, J. R.; Yu, N. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

2012-12-17

We report a demonstration of a very small microwave atomic clock using the 12.6 GHz hyperfine transition of the trapped {sup 171}Yb ions inside a miniature, completely sealed-off 3 cm{sup 3} ion-trap vacuum package. In the ion clock system, all of the components are highly miniaturized with low power consumption except the 369 nm optical pumping laser still under development for miniaturization. The entire clock, including the control electronics, consumes <300 mW. The fractional frequency instability of the miniature Yb{sup +} clock reaches the 10{sup -14} range after a few days of integration.

A Brief Review of Heavy-Ion Radiation Degradation and Failure of Silicon UMOS Power Transistors

Directory of Open Access Journals (Sweden)

Kenneth F. Galloway

2014-09-01

Full Text Available Silicon VDMOS power MOSFET technology is being supplanted by UMOS (or trench power MOSFET technology. Designers of spaceborne power electronics systems incorporating this newer power MOSFET technology need to be aware of several unique threats that this technology may encounter in space. Space radiation threats to UMOS power devices include vulnerabilities to SEB, SEGR, and microdose. There have been relatively few studies presented or published on the effects of radiation on this device technology. The S-O-A knowledge of UMOS power device degradation and failure under heavy-ion exposure is reviewed.

European contributions to the beam source design and R and D of the ITER neutral beam injectors

International Nuclear Information System (INIS)

Massmann, P.; Bayetti, P.; Bucalossi, J.

2001-01-01

The paper reports on the progress made by the European Home Team in strong interaction with the ITER JCT and JAERI regarding several key aspects of the beam source for the ITER injectors: integration of the SINGAP accelerator into the ITER injector design. This is a substantially simpler concept than the MAMuG accelerator of the ITER NBI 'reference design', which has potential for significant cost savings, and which avoids some of the weaknesses of the reference design such as the need for intermediate high voltage potentials from the HV power supply and pressurised gas insulation; high energy negative ion acceleration using a SINGAP accelerator; long pulse (i.e. >1000 s) negative ion source operation in deuterium; RF source development, which could reduce the scheduled maintenance of the ITER injectors (as it uses no filaments), and simplify the transmission line and the auxiliary power supplies for the ion source. (author)

European contributions to the beam source design and R and D of the ITER neutral beam injectors

International Nuclear Information System (INIS)

Massmann, P.; Bayetti, P.; Bucalossi, J.

1999-01-01

The paper reports on the progress made by the European Home Team in strong interaction with the ITER JCT and JAERI regarding several key aspects of the beam source for the ITER injectors: integration of the SINGAP accelerator into the ITER injector design. This is a substantially simpler concept than the MAMuG accelerator of the ITER NBI 'reference design', which has potential for significant cost savings, and which avoids some of the weaknesses of the reference design such as the need for intermediate high voltage potentials from the HV power supply and pressurised gas insulation; high energy negative ion acceleration using a SINGAP accelerator; long pulse (i.e. >1000 s) negative ion source operation in deuterium; RF source development, which could reduce the scheduled maintenance of the ITER injectors (as it uses no filaments), and simplify the transmission line and the auxiliary power supplies for the ion source. (author)

Influence of ion beam energy on SEGR failure thresholds of vertical power MOSFETs

International Nuclear Information System (INIS)

Titus, J.L.; Wheatley, C.F.; Allenspach, M.; Schrimpf, R.D.; Brews, J.R.; Galloway, K.F.; Burton, D.I.; Pease, R.L.

1996-01-01

For the first time, experimental observations and numerical simulations show that the impact energy of the test ion influences the single-event gate rupture (SEGR) failure thresholds of vertical power MOSFETs. Current testing methodology may produce false hardness assurance

Fabrication and Characterization of Li-ion Electrodes for High-Power Energy Storage Devices

OpenAIRE

Lai, Chun-Han

2017-01-01

Renewable energy technologies have been a rapidly emerging option to meet future energy demand. However, their systems require stable, high-power storage devices to overcome fluctuating energy outputs for consistent distribution. Since traditional Li-ion batteries (LIB) are not considered to be capable of fast charging and discharging, we have to develop devices with new chemistry for high-power operation. This dissertation focuses on the development of supercapacitors and high-rate batteries...

Power balance in ELMO Bumpy Torus: bulk electrons and ions in a 37 kW discharge

International Nuclear Information System (INIS)

McNeill, D.H.

1985-10-01

The power balance of the bulk electrons and ions in discharges with 37 kW of applied microwave power in the ELMO Bumpy Torus (EBT) is examined in a zero-dimensional model using data on the intensity and linewidth of the molecular and atomic hydrogen emission. At least 60% of the applied power is ultimately dissipated by processes involving the neutral particles, including dissociation of molecules, ionization of and radiation from atoms, and heating of cold electrons produced during atomic ionization. The molecular influx rate and the density of atoms are used independently to determine the bulk electron particle confinement time, and an upper bound estimate is made of the diffusional power loss from the bulk plasma electrons. Parameters derived from the basic spectroscopic data presented in this paper include the neutral atom density 2 - 5x10 10 cm -3 , incident molecular flux 3 - 5x10 15 cm -2 s -1 , bulk ion temperature approx. =3 eV, and particle confinement time <1.1 ms. The bulk electron energy confinement time is 0.7 ms or less in the standard operating regime. Published data on the nonthermal electron and ion populations in the plasma are used to evaluate approximately the overall energy flow in the discharge. 54 refs

Compact RF ion source for industrial electrostatic ion accelerator

Energy Technology Data Exchange (ETDEWEB)

Kwon, Hyeok-Jung, E-mail: hjkwon@kaeri.re.kr; Park, Sae-Hoon; Kim, Dae-Il; Cho, Yong-Sub [Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongsangbukdo 38180 (Korea, Republic of)

2016-02-15

Korea Multi-purpose Accelerator Complex is developing a single-ended electrostatic ion accelerator to irradiate gaseous ions, such as hydrogen and nitrogen, on materials for industrial applications. ELV type high voltage power supply has been selected. Because of the limited space, electrical power, and robust operation, a 200 MHz RF ion source has been developed. In this paper, the accelerator system, test stand of the ion source, and its test results are described.

Compact RF ion source for industrial electrostatic ion accelerator

Science.gov (United States)

Kwon, Hyeok-Jung; Park, Sae-Hoon; Kim, Dae-Il; Cho, Yong-Sub

2016-02-01

Korea Multi-purpose Accelerator Complex is developing a single-ended electrostatic ion accelerator to irradiate gaseous ions, such as hydrogen and nitrogen, on materials for industrial applications. ELV type high voltage power supply has been selected. Because of the limited space, electrical power, and robust operation, a 200 MHz RF ion source has been developed. In this paper, the accelerator system, test stand of the ion source, and its test results are described.

Molecular dynamics simulations of ion range profiles for heavy ions in light targets

Energy Technology Data Exchange (ETDEWEB)

Lan, C. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 (China); Xue, J.M. [State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 (China); Zhang, Y., E-mail: Zhangy1@ornl.gov [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Morris, J.R. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Zhu, Z. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Gao, Y.; Wang, Y.G.; Yan, S. [State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871 (China); Weber, W.J. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2012-09-01

The determination of stopping powers for slow heavy ions in targets containing light elements is important to accurately describe ion-solid interactions, evaluate ion irradiation effects and predict ion ranges for device fabrication and nuclear applications. Recently, discrepancies of up to 40% between the experimental results and SRIM (Stopping and Range of Ions in Matter) predictions of ion ranges for heavy ions with medium and low energies (<{approx}25 keV/nucleon) in light elemental targets have been reported. The longer experimental ion ranges indicate that the stopping powers used in the SRIM code are overestimated. Here, a molecular dynamics simulation scheme is developed to calculate the ion ranges of heavy ions in light elemental targets. Electronic stopping powers generated from both a reciprocity approach and the SRIM code are used to investigate the influence of electronic stopping on ion range profiles. The ion range profiles for Au and Pb ions in SiC and Er ions in Si, with energies between 20 and 5250 keV, are simulated. The simulation results show that the depth profiles of implanted ions are deeper and in better agreement with the experiments when using the electronic stopping power values derived from the reciprocity approach. These results indicate that the origin of the discrepancy in ion ranges between experimental results and SRIM predictions in the low energy region may be an overestimation of the electronic stopping powers used in SRIM.

Multi-timescale power and energy assessment of lithium-ion battery and supercapacitor hybrid system using extended Kalman filter

Science.gov (United States)

Wang, Yujie; Zhang, Xu; Liu, Chang; Pan, Rui; Chen, Zonghai

2018-06-01

The power capability and maximum charge and discharge energy are key indicators for energy management systems, which can help the energy storage devices work in a suitable area and prevent them from over-charging and over-discharging. In this work, a model based power and energy assessment approach is proposed for the lithium-ion battery and supercapacitor hybrid system. The model framework of the lithium-ion battery and supercapacitor hybrid system is developed based on the equivalent circuit model, and the model parameters are identified by regression method. Explicit analyses of the power capability and maximum charge and discharge energy prediction with multiple constraints are elaborated. Subsequently, the extended Kalman filter is employed for on-board power capability and maximum charge and discharge energy prediction to overcome estimation error caused by system disturbance and sensor noise. The charge and discharge power capability, and the maximum charge and discharge energy are quantitatively assessed under both the dynamic stress test and the urban dynamometer driving schedule. The maximum charge and discharge energy prediction of the lithium-ion battery and supercapacitor hybrid system with different time scales are explored and discussed.

The comparative analysis of the different mechanisms of toroidal rotation in tokamaks

Energy Technology Data Exchange (ETDEWEB)

Sabot, R [Association Euratom-CEA, Centre d` Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Parail, V [Kurchatov Institute, Moscow (Russian Federation)

1994-07-01

The toroidal plasma rotation appears as one the possible mechanism for suppression of plasma turbulence. Several mechanisms are believed to contribute to the toroidal plasma rotation. The results of numerical simulation of the toroidal rotation on JET are presented, where are taken into consideration the following effects: the neoclassical viscosity due to banana and ripple trapped particles, the anomalous viscosity due to plasma turbulence, the momentum input by NBI (neutron beam injection) and ion momentum loss near the separatrix due to prompt ion losses. The NBI appeared to be the principal source of toroidal plasma rotation. 6 refs., 2 figs.

Development of an Ion Chamber for Monitoring the Containment of a Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Song, Tae-Yung; Kim, Han-Soo; Park, Se-Hwan; Ha, Jang-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-05-15

Nuclear power plants need many different types of radiation detectors for different purposes. Neutron detectors are installed inside and outside of the core to check the neutron flux. Scintillation detectors are used to check the fission products included in the liquids and gases of plant system. Geiger-Mueller counters are used for the area radiation monitoring. In addition to the above-mentioned detectors, ion chambers are installed to monitor radiation level of the containment. A few ion chambers are located within the reactor containment to monitor radiation level of an accident case. Therefore, the ion chamber should be capable of monitoring high level radiation dose up to 10{sup 7} R/h. Korea Atomic Energy Research Institute (KAERI) developed an ion chamber for monitoring the radiation dose inside the containment.

Preliminary research results for generation and application of high power ion beams on FLASh II accelerator

International Nuclear Information System (INIS)

Yang Hailiang; Qiu Aici; Zhang Jiasheng; He Xiaoping; Sun Jianfeng; Peng Jianchang; Tang Junping; Ren Shuqing; Ouyang Xiaoping; Zhang Guoguang; Huang Jianjun; Yang Li; Wang Haiyang; Li Jingya; Li Hongyu

2004-01-01

Preliminary results for the generation and application of the high power ion beam (HPIB) on the FLASH II accelerator are reported. The structure and principle of the pinch reflex ion beam diode are introduced. The equation of parapotential flow is corrected for the reduction of diode A-K gap due to the motion of cathode and anode plasma. The HPIB peak current of ∼160 kA is obtained with a peak energy of ∼500 keV. Experimental investigations of generating 6-7 MeV quasi-monoenergetic pulsed γ-rays with high power ion (proton) beams striking 19 F target are presented. In addition, the results of the thermal-mechanical effects on the material irradiated with HPIB, which are applied to the simulation of 1 keV black body radiation x-rays, are also discussed

MeV and GeV prospects for producing a large ion layer configuration for fusion power generation and breeding

International Nuclear Information System (INIS)

McNally, J.R. Jr.

1983-01-01

Injection of multi-MeV molecular hydrogen ions into a magnetic mirror or magnetic mirror well can lead to the production of an ion (or proton-E) Layer with prospects for fusion power generation. This involves: (1) slow (exponential or Lorentz) trapping of protons from dissociation and/or ionization of H 2 + ions; (2) electron cyclotron drive of the electronic temperature to reduce the electron stopping power; (3) production of an Ion-Layer, E-Core plasma configuration having prospects for cold fuel feed with in situ axial acceleration of say D 2 + ions into the negative E-Core; (4) ignited advanced fuel burns in the resulting high beta plasma with excess (free) neutrons available for energy multiplication of fissile fuel breeding; (5) development of a nuclear dynamo with fuel feed, plasma energy, and Ion-Layer current maintenance by fusion products; and (6) a natural divertor end loss of ashes with charge separation permitting a natural direct electrical conversion prospect

Stopping power of liquid water for carbon ions in the energy range between 1 MeV and 6 MeV

International Nuclear Information System (INIS)

Rahm, J M; Baek, W Y; Rabus, H; Hofsäss, H

2014-01-01

The stopping power of liquid water was measured for the first time for carbon ions in the energy range between 1 and 6 MeV using the inverted Doppler shift attenuation method. The feasibility study carried out within the scope of the present work shows that this method is well suited for the quantification of the controversial condensed phased effect in the stopping power for heavy ions in the intermediate energy range. The preliminary results of this work indicate that the stopping power of water for carbon ions with energies prevailing in the Bragg-peak region is significantly lower than that of water vapor. In view of the relatively high uncertainty of the present results, a new experiment with uncertainties less than the predicted difference between the stopping powers of both water phases is planned. (paper)

Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

Science.gov (United States)

Li, Jianlin; Du, Zhijia; Ruther, Rose E.; AN, Seong Jin; David, Lamuel Abraham; Hays, Kevin; Wood, Marissa; Phillip, Nathan D.; Sheng, Yangping; Mao, Chengyu; Kalnaus, Sergiy; Daniel, Claus; Wood, David L.

2017-09-01

Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by 70% from 2008 to 2015, the current battery pack cost (268/kWh in 2015) is still >2 times what the USABC targets (125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. This article discusses three major aspects for cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.

Experimental Investigation from the Operation of a 2 kW Brayton Power Conversion Unit and a Xenon Ion Thruster

Science.gov (United States)

Hervol, David; Mason, Lee; Birchenough, Art; Pinero, Luis

2004-01-01

A 2kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton Converters and ion thrusters are potential candidates for use on future high power NEP mission such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of a existing lower power test hardware provided a cost effective means to investigate the critical electrical interface between the power conversion system and the propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

The stopping power and energy straggling of the energetic C and O ions in polyimide

Energy Technology Data Exchange (ETDEWEB)

Mikšová, R., E-mail: miksova@ujf.cas.cz [Nuclear Physics Institute of the Academy of Science of the Czech Republic v.v.i, 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske Mladeze 8, 400 96 Usti nad Labem (Czech Republic); Macková, A. [Nuclear Physics Institute of the Academy of Science of the Czech Republic v.v.i, 250 68 Rez (Czech Republic); Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske Mladeze 8, 400 96 Usti nad Labem (Czech Republic); Slepička, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2016-03-15

The stopping power and energy straggling of {sup 12}C{sup n+} and {sup 16}O{sup n+} heavy ions in the energy range 5.3–8.0 MeV in 8 μm thick polyimide (PI) foil were measured by means of an indirect transmission method using a half-covered a PIPS detector. Ions scattered from thin gold layer, under the scattering angle 150° were detected and the spectrum of ions penetrating the PI foil and without foil was recorded. The values of the experimentally determined stopping powers were compared to the calculated data by SRIM-2013 and MSTAR codes. Measured data were in good agreement with data calculated by SRIM-2013, especially for C ions was observed better agreement than for O ions. The energy straggling was determined and compared to those calculated by using Bohr’s, Bethe–Livingston and Yang models. The measured energy straggling values in the PI foil was corrected for foil roughness and thickness inhomogeneity determined from AFM. Bethe–Livingston predicting formula has been modified to make it appropriate for thicker targets. The energy straggling determined in our experiment was obtained higher than Bohr’s predicted value; the predictions by Yang are in good agreement with our experiment. Bethe–Livingston formulation of the energy straggling shows better agreement with the experimental data after the modified formula implementation which assumes that the thick target was consisted to be composed of n-number of thin layers. Influence of the charge-exchange phenomena to the energy straggling of C and O ions in PI was discussed.

Interaction of energetic particles with large and small scale instabilities

International Nuclear Information System (INIS)

Guenter, S.; Conway, G.; Graca, S. da; Fahrbach, H.-U.; Forest, C.; Munoz, M. Garcia; Hauff, T.; Hobirk, J.; Igochine, V.; Jenko, F.; Lackner, K.; Lauber, P.; McCarthy, P.; Maraschek, M.; Martin, P.; Poli, E.; Sassenberg, K.; Strumberger, E.; Tardini, G.; Wolfrum, E.; Zohm, H.

2007-01-01

Beyond a certain heating power, measured and predicted distributions of neutral beam injection (NBI) driven currents deviate from each other even in the absence of MHD instabilities. The most reasonable explanation is a redistribution of fast NBI ions on a time scale smaller than the current redistribution time. The hypothesis of a redistribution of fast ions by background turbulence is discussed. Direct numerical simulation of fast test particles in a given field of electrostatic turbulence indicates that for reasonable parameters fast and thermal particle diffusion can indeed be similar. High quality plasma edge density profiles on ASDEX Upgrade and the recent extension of the reflectometry system allow for a direct comparison of observed TAE eigenfunctions with theoretical ones as obtained with the linear, gyrokinetic, global stability code LIGKA. These comparisons support the hypothesis of TAE-frequency crossing the continuum at the plasma edge in ASDEX Upgrade H-mode discharges. A new fast ion loss detector with 1 MHz time resolution allows frequency and phase resolved correlation between the observed losses and low frequency magnetic perturbations such as TAE modes and rotating magnetic islands. Whereas losses caused by TAE modes are known to be due to resonances in velocity space, by modelling the particle drift orbits we were able to explain losses caused by magnetic islands as due to island formation and stochasticity in the drift orbits

Design status and procurement activities of the High Voltage Deck 1 and Bushing for the ITER Neutral Beam Injector

International Nuclear Information System (INIS)

Boldrin, Marco; De Lorenzi, Antonio; Decamps, Hans; Grando, Luca; Simon, Muriel; Toigo, Vanni

2013-01-01

Highlights: ► ITER Neutral Beam Injector includes several non-standard components. ► The design status of the −1 MV dc HVD1 and Bushing is described. ► The paper reports also on the integrated layout of the two components. ► Preliminary electrostatic and thermal analyses are presented. ► Procurement activities are outlined. -- Abstract: The ITER Neutral Beam Injector (NBI) power supply system includes several non-standard components, whose ratings go beyond the present industrial practice. Two of these items, to be procured by Fusion for Energy, are: 1.A −1 MV dc air-insulated Faraday cage, called High Voltage Deck 1 (HVD1), hosting the Ion Source and Extractor Power Supplies (ISEPS) and the associated diagnostics. 2.A −1 MV dc feedthrough, called HVD1-TL Bushing, aimed at connecting the HVD1 to the gas (SF 6 ) insulated Transmission Line (TL), containing inside its High Voltage (HV) conductor all ISEPS power and control cables coming from the HVD1 to be connected to the NBI Ion Source services. The paper deals with the status of the design of the HVD1 and HVD1-TL Bushing, focusing on insulation, mechanical and thermal issues as well as on their integration with the other components of the power supply system. In particular, the insulation issue of the integrated system has been addressed by means of an electrostatic Finite Element (FE) analysis whilst a FE thermal simulation has been carried out to assess the impact of the dissipation of the proposed design of the inner conductors (ISEPS conductors) not actively cooled. Finally, the paper describes the status of procurement strategy and execution

A conceptual design of a negative-ion-grounded advanced tokamak reactor

International Nuclear Information System (INIS)

Yamamoto, Shin; Ohara, Yoshihiro; Tani, Keiji

1988-05-01

The NAVIGATOR concept is based on the negative-ion-grounded 500 keV 20 MW neutral beam injection system (NBI system), which has been proposed and studied at JAERI. The NAVIGATOR concept contains two categories; one is the NAVIGATOR machine as a tokamak reactor, and the other is the NAVIGATOR philosophy as a guiding principle in fusion research. The NAVIGATOR machine implies an NBI heated and full inductive ramped-up reactor. The NAVIGATOR concept should be applied in a phased approach to and beyond the operating goal for the FER (Fusion Experimental Reactor, the next generation tokamak machine in Japan). The mission of the FER is to realize self-ignition and a long controlled burn of about 800 seconds and to develop and test fusion technologies, including the tritium fuel cycle, superconducting magnet, remote maintenance and breeding blanket test modules. The NAVIGATOR concept is composed of three major elements, that is, reliable operation scenarios, reliable maintenability and sufficient flexibility of the reactor. The NAVIGATOR concept well supports the ideas of phased operation and phased construction of the FER, which will result in the reduction of technological risk. The NAVIGATOR concept is expected to bring forth the fruits growing up in the present large tokamak machines in the form of next generation machines. In addition, the NAVIGATOR concept will supply many required databases for the DEMO reactor. The details of the NAVIGATOR concept is described in this paper, and the concept may indicate a feasible strategy for developing fusion research. (author)

Low power multiple shell fusion targets for use with electron and ion beams

International Nuclear Information System (INIS)

Lindl, J.D.; Bangerter, R.O.

1975-01-01

Use of double shell targets with a separate low Z, low density ablator at large radius for the outer shell, reduces the focusing and power requirements while maintaining reasonable aspect ratios. A high Z, high density pusher shell is placed at a much smaller radius in order to obtain an aspect ratio small enough to protect against fluid instability. Velocity multiplication between these shells further lowers the power requirements. Careful tuning of the power profile and intershell density results in a low entropy implosion which allows breakeven at low powers. Ion beams appear to be a promising power source and breakeven at 10-20 Terrawatts with 10 MeV alpha particles appears feasible. Predicted performance of targets with various energy sources is shown and comparison is made with single shell targets

Design philosophy and use of high voltage power systems for multi-megawatt ion beam accelerators

International Nuclear Information System (INIS)

Barber, G.C.; Broverman, A.Y.; Hill, R.E.; Loring, C.M.; Ponte, N.S.

1977-01-01

The requirements for a neutral beam high voltage power system are derived from the characteristics of the ion source. High voltage system component characteristic requirements and choices are described

A series of coordination polymers constructed from R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands: Syntheses, structures and fluorescence properties

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yong-Hong, E-mail: zhou21921@sina.com [School of Chemistry and Material Science, Huaibei Normal University, Huaibei 235000 (China); Zhou, Xu-Wan; Zhou, Su-Rong [School of Chemistry and Material Science, Huaibei Normal University, Huaibei 235000 (China); Tian, Yu-Peng; Wu, Jie-Ying [Department of Chemistry and Chemical Technology, Anhui University, Hefei 230039 (China)

2017-01-15

Six novel Zn(II), Cd(II), and Cu(II) mixed-ligand coordination complexes, namely, [Zn{sub 2}Na(sip){sub 2}(bpp){sub 3}(Hbpp)(H{sub 2}O){sub 2}]·8H{sub 2}O (1), [Cd{sub 3}(sip){sub 2}(nbi){sub 6}(H{sub 2}O){sub 2}]·7H{sub 2}O (2), [Zn(sip)(nbi){sub 2}(H{sub 2}O)]·Hnbi·3H{sub 2}O (3), [Cd(hip)(nbi){sub 2}(H{sub 2}O)]·nbi·5H{sub 2}O (4), [Cd{sub 2}(nip){sub 2}(nbi){sub 2}(H{sub 2}O){sub 2}]·DMF (5), and [Cu(nip)(nbi)(H{sub 2}O){sub 2}]·H{sub 2}O (6) (H{sub 3}sip=5-sulfoisophthalic acid, H{sub 2}hip=5-hydroxylisophthalic acid, H{sub 2}nip=5-nitroisophthalic acid, bpp=1,3-bis(4-pyridyl)propane, and nbi=6-nitrobenzimidazole) have been synthesized hydrothermally by the self-assembly of R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands. Single crystal X-ray analyses reveal that two Zn(II) ions and one Na(I) ion of complex 1 are linked through O atoms to generate a 1D linear chain. Then the 2D supramolecular architectures are constructed via intermolecular interactions. In complex 2, the Cd1 ions are connected by bridging carboxyl groups from sip{sup 3−} anions to form 1D double chain, which are further connected by Cd2 ions to afford 2D layer structure. The adjacent 2D layers are further linked via hydrogen-bonding interactions to give 3D supramolecular network. Compounds 3–5 show 1D chain structures, which are assembled into 2D or 3D supramolecular frameworks via weak interactions. In compound 6, the Cu(II) ions are bridged by the nip{sup 2−} ligands to form 48-membered ring, which is assembled into 1Dchain via the π-π stacking interaction. In addition, the thermal stabilities and fluorescence properties of these compounds have also been studied. - Graphical abstract: A series of Cd(II)/Zn(II)/ Cu(II) coordination polymers based on R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands have been synthesized under hydrothermal conditions and structurally characterized. Photoluminescent properties

Direct measurement of the transition from edge to core power coupling in a light-ion helicon source

Science.gov (United States)

Piotrowicz, P. A.; Caneses, J. F.; Showers, M. A.; Green, D. L.; Goulding, R. H.; Caughman, J. B. O.; Biewer, T. M.; Rapp, J.; Ruzic, D. N.

2018-05-01

We present time-resolved measurements of an edge-to-core power transition in a light-ion (deuterium) helicon discharge in the form of infra-red camera imaging of a thin stainless steel target plate on the Proto-Material Exposure eXperiment device. The time-resolved images measure the two-dimensional distribution of power deposition in the helicon discharge. The discharge displays a mode transition characterized by a significant increase in the on-axis electron density and core power coupling, suppression of edge power coupling, and the formation of a fast-wave radial eigenmode. Although the self-consistent mechanism that drives this transition is not yet understood, the edge-to-core power transition displays characteristics that are consistent with the discharge entering a slow-wave anti-resonant regime. RF magnetic field measurements made across the plasma column, together with the power deposition results, provide direct evidence to support the suppression of the slow-wave in favor of core plasma production by the fast-wave in a light-ion helicon source.

Energy dependence of the stopping power of MeV 16O ions in a laser-produced plasma

International Nuclear Information System (INIS)

Sakumi, A.; Shibata, K.; Sato, R.; Tsubuku, K.; Nishimoto, T.; Hasegawa, J.; Ogawa, M.; Oguri, Y.; Katayama, T.

2001-01-01

The energy dependence of the stopping power of 16 O ions in a laser-produced plasma target was experimentally investigated in the projectile energy range of 150-350 keV/u. In order to produce the target plasma a Q-Switched Nd-glass laser was focused onto a small lithium hydride (LiH) pellet. The plasma electron temperature and the electron line density were 15 eV and 2x10 17 cm -2 , respectively. The energy loss of 16 O ions in the plasma was measured by a time-of-flight (TOF) method. We found that the stopping power in the plasma agreed with the theoretical estimation based on a modified Bohr equation with correction at low velocities. In this evaluation, the effective charge of the projectile was calculated by means of rate equations on the loss and capture of electrons. It has been also found that in this projectile energy range the stopping power of the 16 O ions in the plasma still increases with decreasing projectile energy, while it decreases in cold equivalent

Design study of a neutral beam injection system for the JAERI Experimental Fusion Reactor (JXFR)

International Nuclear Information System (INIS)

1977-10-01

Design study has been made of a 200 kV, 45 MW D 0 neutral beam injection system for the JAERI Experimental Fusion Reactor (JXFR) covering the following: determination of the ion source specifications, design of components such as ion source with extraction electrodes, energy converter, cryopump and cooling system, and estimations of the energy conversion efficiency, overall power efficiency and total power required for operation of the NBI system, and also a hydrogen isotope separation method using cryo-sorption pumps. Optimizations and parameter studies of the neutralizing cell length, gas flow rate, operating pressure of ion sources, total pumping speed and pressure of energy converters are made in the design study based on reactor plasma requirements. Hollow cathode ion sources are proposed because of the extended operation time at low gas pressure (about 4.5 x 10 -3 Torr) and the high gas efficiency (40%). Life of the extraction electrodes is determined by blistering due to deuterium ions. Fast neutron radiation damage is relatively small. In-line direct converters with grounded recovery electrodes and neutralizing cells floated at negative potential -190 kV are used to recover residual deuterium ion energy without interrupting the neutral beam trajectories. Energy conversion efficiency of 80% and overall power efficiency of about 40% are obtained. (auth.)

A revisit to self-excited push pull vacuum tube radio frequency oscillator for ion sources and power measurements

International Nuclear Information System (INIS)

Hlondo, L. R.; Lalremruata, B.; Punte, L. R. M.; Rebecca, L.; Lalnunthari, J.; Thanga, H. H.

2016-01-01

Self-excited push-pull vacuum tube oscillator is one of the most commonly used oscillators in radio frequency (RF)-ion plasma sources for generation of ions using radio frequency. However, in spite of its fundamental role in the process of plasma formation, the working and operational characteristics are the most frequently skip part in the descriptions of RF ion sources in literatures. A more detailed treatment is given in the present work on the RF oscillator alone using twin beam power tetrodes 829B and GI30. The circuit operates at 102 MHz, and the oscillation conditions, stability in frequency, and RF output power are studied and analyzed. A modified form of photometric method and RF peak voltage detection method are employed to study the variation of the oscillator output power with plate voltage. The power curves obtained from these measurements are quadratic in nature and increase with increase in plate voltage. However, the RF output power as measured by photometric methods is always less than the value calculated from peak voltage measurements. This difference is due to the fact that the filament coil of the ordinary light bulb used as load/detector in photometric method is not a perfect inductor. The effect of inductive reactance on power transfer to load was further investigated and a technique is developed to estimate the amount of power correction needed in the photometric measurement result.

Multiple output power supply circuit for an ion engine with shared upper inverter

Science.gov (United States)

Cardwell, Jr., Gilbert I. (Inventor); Phelps, Thomas K. (Inventor)

2001-01-01

A power supply circuit for an ion engine suitable for a spacecraft is coupled to a bus having a bus input and a bus return. The power supply circuit has a first primary winding of a first transformer. An upper inverter circuit is coupled to the bus input and the first primary winding. The power supply circuit further includes a first lower inverter circuit coupled to the bus return and the first primary winding. The second primary winding of a second transformer is coupled to the upper inverter circuit. A second lower inverter circuit is coupled to the bus return and the second primary winding.

A high energy and power Li-ion capacitor based on a TiO2 nanobelt array anode and a graphene hydrogel cathode.

Science.gov (United States)

Wang, Huanwen; Guan, Cao; Wang, Xuefeng; Fan, Hong Jin

2015-03-25

A novel hybrid Li-ion capacitor (LIC) with high energy and power densities is constructed by combining an electrochemical double layer capacitor type cathode (graphene hydrogels) with a Li-ion battery type anode (TiO(2) nanobelt arrays). The high power source is provided by the graphene hydrogel cathode, which has a 3D porous network structure and high electrical conductivity, and the counter anode is made of free-standing TiO(2) nanobelt arrays (NBA) grown directly on Ti foil without any ancillary materials. Such a subtle designed hybrid Li-ion capacitor allows rapid electron and ion transport in the non-aqueous electrolyte. Within a voltage range of 0.0-3.8 V, a high energy of 82 Wh kg(-1) is achieved at a power density of 570 W kg(-1). Even at an 8.4 s charge/discharge rate, an energy density as high as 21 Wh kg(-1) can be retained. These results demonstrate that the TiO(2) NBA//graphene hydrogel LIC exhibits higher energy density than supercapacitors and better power density than Li-ion batteries, which makes it a promising electrochemical power source. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metal negative ion beam extraction from a radio frequency ion source

Energy Technology Data Exchange (ETDEWEB)

Kanda, S.; Yamada, N.; Kasuya, T.; Romero, C. F. P.; Wada, M.

2015-04-08

A metal ion source of magnetron magnetic field geometry has been designed and operated with a Cu hollow target. Radio frequency power at 13.56 MHz is directly supplied to the hollow target to maintain plasma discharge and induce self-bias to the target for sputtering. The extraction of positive and negative Cu ion beams have been tested. The ion beam current ratio of Cu{sup +} to Ar{sup +} has reached up to 140% when Ar was used as the discharge support gas. Cu{sup −} ion beam was observed at 50 W RF discharge power and at a higher Ar gas pressure in the ion source. Improvement of poor RF power matching and suppression of electron current is indispensable for a stable Cu{sup −} ion beam production from the source.

Ion confinement and radiation losses in the Advanced Toroidal Facility

International Nuclear Information System (INIS)

Isler, R.C.; Colchin, R.J.; Wade, M.R.; Lyon, J.F.; Fowler, R.H.; Rome, J.A.; Hiroe, S.; Baylor, L.R.; England, A.; Ma, C.H.; Rasmussen, D.A.; Ochando, M.; Paul, S.

1991-01-01

Collapses of stored energy are typically observed in low-density (anti n e ∼ 10 13 cm -3 ) extensively gettered ATF plasmas when the electron density rises to the ECH cutoff point, and the central heating is supplied only by neutral- beam-injection (NBI). However, the decline of stored energy can be avoided if the density is raised rapidly to about 5 x 10 13 cm -3 . Three mechanisms have been proposed to explain the collapses: (1) impurity radiation, (2) excitation of an electron instability driven by the neutral beams, or (3) poor coupling of the beam ions to the thermal plasmas. Detailed spectroscopic studies of plasma cleanliness as a function of the gettering procedure have shown that radiation is an unlikely candidate for initiating collapses, although it may become an important loss mechanism once the electron temperature has fallen to a low level. No specific electron instability has yet been identified with injection, but recent experimental and computational work indicates that losses by shinethrough and charge exchange strongly influence the evolution of low-density plasmas. This report discusses the beam particle losses, thermal ions, and the evolution of radiation profiles

Study of the general plasma characteristics of a high power multifilament ion source

International Nuclear Information System (INIS)

Schoenberg, K.F.

1979-09-01

A general assessment of the steady state and time dependent plasma properties which characterize a high power multifilament ion source is presented. Steady state measurements, obtained via a pulsed electrostatic probe data acquisition system, are described. Fluctuation measurements, obtained via a broadband digital spectral analysis system, are also given

Particle-filtering-based estimation of maximum available power state in Lithium-Ion batteries

International Nuclear Information System (INIS)

Burgos-Mellado, Claudio; Orchard, Marcos E.; Kazerani, Mehrdad; Cárdenas, Roberto; Sáez, Doris

2016-01-01

Highlights: • Approach to estimate the state of maximum power available in Lithium-Ion battery. • Optimisation problem is formulated on the basis of a non-linear dynamic model. • Solutions of the optimisation problem are functions of state of charge estimates. • State of charge estimates computed using particle filter algorithms. - Abstract: Battery Energy Storage Systems (BESS) are important for applications related to both microgrids and electric vehicles. If BESS are used as the main energy source, then it is required to include adequate procedures for the estimation of critical variables such as the State of Charge (SoC) and the State of Health (SoH) in the design of Battery Management Systems (BMS). Furthermore, in applications where batteries are exposed to high charge and discharge rates it is also desirable to estimate the State of Maximum Power Available (SoMPA). In this regard, this paper presents a novel approach to the estimation of SoMPA in Lithium-Ion batteries. This method formulates an optimisation problem for the battery power based on a non-linear dynamic model, where the resulting solutions are functions of the SoC. In the battery model, the polarisation resistance is modelled using fuzzy rules that are function of both SoC and the discharge (charge) current. Particle filtering algorithms are used as an online estimation technique, mainly because these algorithms allow approximating the probability density functions of the SoC and SoMPA even in the case of non-Gaussian sources of uncertainty. The proposed method for SoMPA estimation is validated using the experimental data obtained from an experimental setup designed for charging and discharging the Lithium-Ion batteries.

Investigation of plasma parameters at BATMAN for variation of the Cs evaporation asymmetry and comparing two driver geometries

Science.gov (United States)

Wimmer, C.; Fantz, U.; Aza, E.; Jovović, J.; Kraus, W.; Mimo, A.; Schiesko, L.

2017-08-01

The Neutral Beam Injection (NBI) system for fusion devices like ITER and, beyond ITER, DEMO requires large scale sources for negative hydrogen ions. BATMAN (Bavarian Test Machine for Negative ions) is a test facility attached with the prototype source for the ITER NBI (1/8 source size of the ITER source), dedicated to physical investigations due to its flexible access for diagnostics and exchange of source components. The required amount of negative ions is produced by surface conversion of hydrogen atoms or ions on caesiated surfaces. Several diagnostic tools (Optical Emission Spectroscopy, Cavity Ring-Down Spectroscopy for H-, Langmuir probes, Tunable Diode Laser Absorption Spectroscopy for Cs) allow the determination of plasma parameters in the ion source. Plasma parameters for two modifications of the standard prototype source have been investigated: Firstly, a second Cs oven has been installed in the bottom part of the back plate in addition to the regularly used oven in the top part of the back plate. Evaporation from the top oven only can lead to a vertically asymmetric Cs distribution in front of the plasma grid. Using both ovens, a symmetric Cs distribution can be reached - however, in most cases no significant change of the extracted ion current has been determined for varying Cs symmetry if the source is well-conditioned. Secondly, BATMAN has been equipped with a much larger, racetrack-shaped RF driver (area of 32×58 cm2) instead of the cylindrical RF driver (diameter of 24.5 cm). The main idea is that one racetrack driver could substitute two cylindrical drivers in larger sources with increased reliability and power efficiency. For the same applied RF power, the electron density is lower in the racetrack driver due to its five times higher volume. The fraction of hydrogen atoms to molecules, however, is at a similar level or even slightly higher, which is a promising result for application in larger sources.

Synchronization method of digital pulse power supply for heavy ions accelerator in Lanzhou

International Nuclear Information System (INIS)

Wang Rongkun; Zhao Jiang; Wu Fengjun; Zhang Huajian; Chen Youxin; Huang Yuzhen; Gao Daqing; Zhou Zhongzu; Yan Huaihai; Yan Hongbin

2013-01-01

The performance of the synchrotron depends on its synchronization. A kind of synchronization method of digital pulse power supply in Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring (HIRFL-CSR) was presented in detail, which is a kind of system on a programmable chip (SOPC) based on optical fiber and optical-custom component. The test of the digital power supply was performed and the current wave forms of pulse mode were given. The results show that all targets can meet the design requirements. (authors)

A demonstration of magnetic field optimization in LHD

Energy Technology Data Exchange (ETDEWEB)

Murakami, S.; Yamada, H. [National Inst. for Fusion Science, Toki, Gifu (Japan); Wakasa, A. [Hokkaido Univ., Graduate School of Engineering, Sapporo, Hokkaido (JP)] [and others

2002-11-01

An optimized configuration of the neoclassical transport and the energetic particle confinement to a level typical of so-called 'advanced stellarators' is found by shifting the magnetic axis position in LHD. Electron heat transport and NBI beam ion distribution are investigated in low-collisionality LHD plasma in order to study the magnetic field optimization effect on the thermal plasma transport and the energetic particle confinement. A higher electron temperature is obtained in the optimized configuration, and the transport analysis suggests a considerable effect of neoclassical transport on the electron heat transport assuming the ion-root level of radial electric field. Also a higher energetic ion distribution of NBI beam ions is observed showing the improvement of the energetic particle confinement. These obtained results support a future reactor design by magnetic field optimization in a non-axisymmetric configuration. (author)

A demonstration of magnetic field optimization in LHD

Energy Technology Data Exchange (ETDEWEB)

Murakami, S.; Yamada, H. [National Inst. for Fusion Science, Toki, Gifu (Japan); Wakasa, A. [Hokkaido Univ., Graduate School of Engineering, Sapporo, Hokkaido (JP)] [and others

2002-10-01

An optimized configuration of the neoclassical transport and the energetic particle confinement to a level typical of so-called 'advanced stellarators' is found by shifting the magnetic axis position in LHD. Electron heat transport and NBI beam ion distribution are investigated in low-collisionality LHD plasma in order to study the magnetic field optimization effect on the thermal plasma transport and the energetic particle confinement. A higher electron temperature is obtained in the optimized configuration, and the transport analysis suggests a considerable effect of neoclassical transport on the electron heat transport assuming the ion-root level of radial electric field. Also a higher energetic ion distribution of NBI beam ions is observed showing the improvement of the energetic particle confinement. These obtained results support a future reactor design by magnetic field optimization in a non-axisymmetric configuration. (author)

Design, manufacture and factory testing of the Ion Source and Extraction Power Supplies for the SPIDER experiment

International Nuclear Information System (INIS)

Bigi, Marco; Rinaldi, Luigi; Simon, Muriel; Sita, Luca; Taddia, Giuseppe; Carrozza, Saverino; Decamps, Hans; Luchetta, Adriano; Meddour, Abdelraouf; Moressa, Modesto; Morri, Cristiano; Musile Tanzi, Antonio; Recchia, Mauro; Wagner, Uwe; Zamengo, Andrea; Toigo, Vanni

2015-01-01

Highlights: • 5 MVA ion source power supplies effectively integrated in 150 m"2 Faraday cage. • Load protection and performance requirements met of custom design high voltage power supplies. • 200 kW tetrode oscillator with 200 kHz frequency range successfully tested. - Abstract: The SPIDER experiment, currently under construction at the Neutral Beam Test Facility in Padua, Italy, is a full-size prototype of the ion source for the ITER Neutral Beam Injectors. The Ion Source and Extraction Power Supplies (ISEPS) for SPIDER are supplied by OCEM Energy Technology s.r.l. (OCEM) under a procurement contract with Fusion for Energy (F4E) covering also the units required for MITICA and ITER injectors. The detailed design of SPIDER ISEPS was finalized in 2011 and manufacture of most components completed by end 2013. The Factory Acceptance Tests took place early 2014. ISEPS, with an overall power rating of 5 MVA, form a heterogeneous set of items including solid state power converters and 1 MHz radiofrequency generators of 200 kW output power. The paper presents the main features of the detailed design developed by OCEM, focusing in particular on the high output voltage pulse step modulators, the high output current resonant converters, the radiofrequency generators by HIMMELWERK GmbH and the architecture and implementation of the complex control system. Details are given on non-standard factory tests verifying the insulation requirements specific to this application. Performance of ISEPS during the factory acceptance tests is described, with emphasis on demonstration of the load protection requirements, a crucial point for all neutral beam power supplies. Finally, key dates of SPIDER ISEPS installation and site testing schedule are provided.

Design, manufacture and factory testing of the Ion Source and Extraction Power Supplies for the SPIDER experiment

Energy Technology Data Exchange (ETDEWEB)

Bigi, Marco, E-mail: marco.bigi@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Rinaldi, Luigi [OCEM Energy Technology, Via della Solidarietà 2/1, 40056 Valsamoggia (località Crespellano), Bologna (Italy); Simon, Muriel [Fusion for Energy, Josep Pla 2, 08019 Barcelona (Spain); Sita, Luca; Taddia, Giuseppe; Carrozza, Saverino [OCEM Energy Technology, Via della Solidarietà 2/1, 40056 Valsamoggia (località Crespellano), Bologna (Italy); Decamps, Hans [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul lez Durance (France); Luchetta, Adriano [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Meddour, Abdelraouf [HIMMELWERK Hoch- und Mittelfrequenzanlagen GmbH, Jopestr. 10, 72072 Tübingen (Germany); Moressa, Modesto [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Morri, Cristiano; Musile Tanzi, Antonio [OCEM Energy Technology, Via della Solidarietà 2/1, 40056 Valsamoggia (località Crespellano), Bologna (Italy); Recchia, Mauro [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Wagner, Uwe [HIMMELWERK Hoch- und Mittelfrequenzanlagen GmbH, Jopestr. 10, 72072 Tübingen (Germany); Zamengo, Andrea; Toigo, Vanni [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy)

2015-10-15

Highlights: • 5 MVA ion source power supplies effectively integrated in 150 m{sup 2} Faraday cage. • Load protection and performance requirements met of custom design high voltage power supplies. • 200 kW tetrode oscillator with 200 kHz frequency range successfully tested. - Abstract: The SPIDER experiment, currently under construction at the Neutral Beam Test Facility in Padua, Italy, is a full-size prototype of the ion source for the ITER Neutral Beam Injectors. The Ion Source and Extraction Power Supplies (ISEPS) for SPIDER are supplied by OCEM Energy Technology s.r.l. (OCEM) under a procurement contract with Fusion for Energy (F4E) covering also the units required for MITICA and ITER injectors. The detailed design of SPIDER ISEPS was finalized in 2011 and manufacture of most components completed by end 2013. The Factory Acceptance Tests took place early 2014. ISEPS, with an overall power rating of 5 MVA, form a heterogeneous set of items including solid state power converters and 1 MHz radiofrequency generators of 200 kW output power. The paper presents the main features of the detailed design developed by OCEM, focusing in particular on the high output voltage pulse step modulators, the high output current resonant converters, the radiofrequency generators by HIMMELWERK GmbH and the architecture and implementation of the complex control system. Details are given on non-standard factory tests verifying the insulation requirements specific to this application. Performance of ISEPS during the factory acceptance tests is described, with emphasis on demonstration of the load protection requirements, a crucial point for all neutral beam power supplies. Finally, key dates of SPIDER ISEPS installation and site testing schedule are provided.

Lithium-ion backup batteries for coping extended loss of AC power (ELAP)

International Nuclear Information System (INIS)

Chang, Choong-koo

2017-01-01

Per NRC Regulations Title 10, Code of Federal Regulations (CFR) 50.63 'Loss of all alternating current power' all Korean nuclear power plants have a coping capability for SBO conditions for a limited time ranging from approximately eight (8) to sixteen (16) hours. The 125V DC systems are designed for eight (8) hours range except Class 1E channel A and B 125V DC system of which duty cycle is 2 hours in APR1400. The strategies proposed by this paper for coping extended loss of AC power (ELAP) involve a three-phase approach. In the first extend class 1E batteries' backup time until 24 hours. Then augment class 1E batteries with Lithium-ion batteries by 72 hours from the event initiation. In addition, obtain additional capability and redundancy from off-site equipment until power systems are restored or commissioned. (author)

High-power pulsed light ion beams for applications in fusion- and matter research

International Nuclear Information System (INIS)

Bluhm, H.; Karow, H.U.; Rusch, D.; Zieher, K.W.

1982-01-01

The foundations of ultrahigh-power pulse techniques are described together with the two pulse generators KALIF (Karlsruhe Light lion Facility) and Pollux of the INR. The physical principles and diagnostics of ion beam production are discussed as well as possible applications in the field of fusion research. (orig./HT) [de

Power capability prediction for lithium-ion batteries based on multiple constraints analysis

International Nuclear Information System (INIS)

Pan, Rui; Wang, Yujie; Zhang, Xu; Yang, Duo; Chen, Zonghai

2017-01-01

Highlights: • Multiple constraints for peak power capability prediction are deeply analyzed. • Multi-limited method is proposed for the peak power capability prediction of LIBs. • The EKF is used for the model based peak power capability prediction. • The FUDS and UDDS profiles are executed to evaluate the proposed method. - Abstract: The power capability of the lithium-ion battery is a key performance indicator for electric vehicle, and it is intimately correlated with the acceleration, regenerative braking and gradient climbing power requirements. Therefore, an accurate power capability or state-of-power prediction is critical to a battery management system, which can help the battery to work in suitable area and prevent the battery from over-charging and over-discharging. However, the power capability is easily affected by dynamic load, voltage variation and temperature. In this paper, three different constraints in power capability prediction are introduced, and the advantages and disadvantages of the three methods are deeply analyzed. Furthermore, a multi-limited approach for the power capability prediction is proposed, which can overcome the drawbacks of the three methods. Subsequently, the extended Kalman filter algorithm is employed for model based state-of-power prediction. In order to verify the proposed method, diverse experiments are executed to explore the efficiency, robustness, and precision. The results indicate that the proposed method can improve the precision and robustness obviously.

The use of pulsed power ion/electron beams for studying of units of electronuclear reactor

Energy Technology Data Exchange (ETDEWEB)

Korenev, S A; Korenev, A S; Puzynin, I V; Samojlov, V N; Sissakyan, A N [Joint Institute for Nuclear Research, Dubna (Russian Federation)

1997-12-31

The problems associated with the use of power pulsed ion beams for studying some units of the model electronuclear installation are considered. This makes it possible to analyze the problem of heating loads on the targets, entrance and exit windows for beams of charged particles. The methods of increasing the life-time of these thin foil based windows by surface modification of the materials by high current pulsed ion beams are considered. (author). 4 figs., 5 refs.

The use of pulsed power ion/electron beams for studying of units of electronuclear reactor

Energy Technology Data Exchange (ETDEWEB)

Korenev, S.A.; Korenev, A.S.; Puzynin, I.V.; Samoilov, V.N.; Sissakian, A.N. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)

1997-09-01

The questions of using power pulsed ion beams for studying some units of model`s electronuclear installation are considered in this report. It allows to analyze the question of heating loads on the targets, entering and output windows for beams of charge particles. The methods of increasing a life-time of these windows on the basis of thin foils with help of surface modification of materials by high current pulsed ion beams are considered. 5 refs., 4 figs.

The use of pulsed power ion/electron beams for studying of units of electronuclear reactor

International Nuclear Information System (INIS)

Korenev, S.A.; Korenev, A.S.; Puzynin, I.V.; Samojlov, V.N.; Sissakyan, A.N.

1996-01-01

The problems associated with the use of power pulsed ion beams for studying some units of the model electronuclear installation are considered. This makes it possible to analyze the problem of heating loads on the targets, entrance and exit windows for beams of charged particles. The methods of increasing the life-time of these thin foil based windows by surface modification of the materials by high current pulsed ion beams are considered. (author). 4 figs., 5 refs

The use of pulsed power ion/electron beams for studying of units of electronuclear reactor

International Nuclear Information System (INIS)

Korenev, S.A.; Korenev, A.S.; Puzynin, I.V.; Samoilov, V.N.; Sissakian, A.N.

1997-01-01

The questions of using power pulsed ion beams for studying some units of model's electronuclear installation are considered in this report. It allows to analyze the question of heating loads on the targets, entering and output windows for beams of charge particles. The methods of increasing a life-time of these windows on the basis of thin foils with help of surface modification of materials by high current pulsed ion beams are considered. 5 refs., 4 figs

Stopping powers of havar and effective charge for 1.4-3.2 MeV/u {sup 127}I-ions

Energy Technology Data Exchange (ETDEWEB)

Alanko, T. E-mail: tommi.alanko@phys.jyu.fi; Hyvoenen, J.; Kylloenen, V.; Raeisaenen, J.; Virtanen, A

2000-06-01

Stopping powers of havar for 1.4-3.2 MeV/u {sup 127}I-ions have been determined by the transmission technique using two geometrical arrangements. No previous data have been published for havar with this ion. The experimental data are compared with predictions obtained by using Bragg's additivity rule with various parametrizations of the stopping power found in the literature. The values obtained by the parametrizations underestimate the experimental data by 5-11%. The empirical correction scheme of Thwaites yields values in rather good agreement with the present results, especially at energies above 1.9 MeV/u. The effective charges of the {sup 127}I ions were also deduced from the experimental data.

Coupling of an applied field magnetically insulated ion diode to a high power magnetically insulated transmission line system

International Nuclear Information System (INIS)

Maenchen, J.E.

1983-01-01

The coupling of energy from a high power pulsed accelerator through a long triplate magnetically insulated transmission line (MITL) in vacuum to an annular applied magnetic field insulated extraction ion diode is examined. The narrow power transport window and the wave front erosion of the MITL set stringent impedance history conditions on the diode load. A new ion diode design developed to satisfy these criteria with marginal electron insulation is presented. The LION accelerator is used to provide a positive polarity 1.5 MV, 350 kA, 40 ns FWHM pulse with a 30 kA/ns current rate from a triplate MITL source. A transition converts the triplate into a cylindrical cross section which flares into the ion diode load. Extensive current and voltage measurements performed along this structure and on the extracted ion beam provide conclusive evidence that the self insulation condition of the MITL is maintained in the transition by current loss alone. The ion diode utilizes a radial magnetic field between a grounded cathode annular emission tip and a disk anode. A 50 cm 2 dielectric/metal anode area serves as the ion plasma source subject to direct electron bombardment from the opposing cathode tip under marginal magnetic insulation conditions. The ions extracted cross the radial magnetic field and exit the diode volume as an annular cross section beam of peak current about 100 kA. The diode current gradually converts from the initial electron flow to nearly 100% ion current after 30 ns, coupling 60% of the diode energy into ions

Effect of 50 MeV Li3+ ion irradiation on electrical characteristics of high speed NPN power transistor

International Nuclear Information System (INIS)

Dinesh, C.M.; Ramani; Radhakrishna, M.C.; Dutt, R.N.; Khan, S.A.; Kanjilal, D.

2008-01-01

Silicon NPN overlay RF power high speed commercial bipolar junction transistors (BJTs) find applications in military, space and communication equipments. Here we report the effect of 50 MeV Li 3+ ion irradiation in the fluence range 1 x 10 11 -1.8 x 10 12 ions cm -2 on NPN power transistor. The range (R), electronic energy loss (S e ), nuclear energy loss (S n ), total ionizing dose (TID) and total displacement damage (D d ) in the silicon target are calculated from TRIM Monte Carlo Code. Output resistance is 3.568 x 10 4 Ω for unirradiated device and it increases to 6 x 10 7 Ω as the fluence is increased from 1 x 10 11 to 1.8 x 10 12 ions cm -2 . The capacitance of the emitter-base junction of the transistor decreases and dielectric loss of the emitter-base junction increases with increase in ion fluence. The built in voltage of the unirradiated sample is 0.5 V and it shifts to 0.4 V after irradiation at fluence of 1.8 x 10 12 ions cm -2 and the corresponding doping density reduced to 5.758 x 10 16 cm -3 . The charge carrier removal rate varies linearly with the increase in ion fluence

Hydrogen ion species analysis and related neutral beam injection power assessment in the Heliotron E neutral beam injection system

International Nuclear Information System (INIS)

Sano, Fumimichi; Obiki, Tokuhiro; Sasaki, Akihiko; Iiyoshi, Atsuo; Uo, Koji

1982-01-01

The hydrogen ion species in a Heliotron E neutral beam injection system of maximum electric power 6.3 MW were analyzed in order to assess the neutral beam power injected into the torus. The masimum p roton ratio of the cylindrical bucket type ion source used was observed to be more than 90 percent assuming that the angular divergences for the respective species in the beam are the same. The experimental data are compared with calculations using a particle balance model. The analysis indicates that the net injection power reaches nearly 2.7 MW at the optimal conditions of the system considering the geometrical limitation of the neutral beam path. (author)

Self-sputtering runaway in high power impulse magnetron sputtering: The role of secondary electrons and multiply charged metal ions

International Nuclear Information System (INIS)

Anders, Andre

2008-01-01

Self-sputtering runaway in high power impulse magnetron sputtering is closely related to the appearance of multiply charged ions. This conclusion is based on the properties of potential emission of secondary electrons and energy balance considerations. The effect is especially strong for materials whose sputtering yield is marginally greater than unity. The absolute deposition rate increases ∼Q 1/2 , whereas the rate normalized to the average power decreases ∼Q -1/2 , with Q being the mean ion charge state number