The reversed-field pinch as a poloidal-field-dominated, compact, high-power-density fusion system

International Nuclear Information System (INIS)

Krakowski, R.A.

1988-01-01

This paper discusses the feasibility of reversed-field pinch devices as future thermonuclear reactors. Safety, cost, ion temperatures, Lawson numbers, and power densities are reviewed for these types of devices. 12 refs., 2 figs., 1 tab

Study on Tensile Fatigue Behavior of Thermal Butt Fusion in Safety Class III High-Density Polyethylene Buried Piping in Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Sung; Lee, Young Ju [Sunchon National University, Suncheon (Korea, Republic of); Oh, Young Jin [KEPCO E and C, Yongin (Korea, Republic of)

2015-01-15

High-density polyethylene (HDPE) piping, which has recently been applied to safety class III piping in nuclear power plants, can be butt-joined through the thermal fusion process, which heats two fused surfaces and then subject to axial pressure. The thermal fusion process generates bead shapes on the butt fusion. The stress concentrations caused by the bead shapes may reduce the fatigue lifetime. Thus, investigating the effect of the thermal butt fusion beads on fatigue behavior is necessary. This study examined the fatigue behavior of thermal butt fusion via a tensile fatigue test under stress-controlled conditions using finite element elastic stress analysis. Based on the results, the presence of thermal butt fusion beads was confirmed to reduce the fatigue lifetime in the low-cycle fatigue region while having a negligible effect in the medium- and high-cycle fatigue regions.

Study on Tensile Fatigue Behavior of Thermal Butt Fusion in Safety Class III High-Density Polyethylene Buried Piping in Nuclear Power Plants

International Nuclear Information System (INIS)

Kim, Jong Sung; Lee, Young Ju; Oh, Young Jin

2015-01-01

High-density polyethylene (HDPE) piping, which has recently been applied to safety class III piping in nuclear power plants, can be butt-joined through the thermal fusion process, which heats two fused surfaces and then subject to axial pressure. The thermal fusion process generates bead shapes on the butt fusion. The stress concentrations caused by the bead shapes may reduce the fatigue lifetime. Thus, investigating the effect of the thermal butt fusion beads on fatigue behavior is necessary. This study examined the fatigue behavior of thermal butt fusion via a tensile fatigue test under stress-controlled conditions using finite element elastic stress analysis. Based on the results, the presence of thermal butt fusion beads was confirmed to reduce the fatigue lifetime in the low-cycle fatigue region while having a negligible effect in the medium- and high-cycle fatigue regions

High-energy fusion: A quest for a simple, small and environmentally acceptable colliding-beam fusion power source

International Nuclear Information System (INIS)

Maglich, B.

1978-01-01

Fusion goals should be lowered for a speedier research and development of a less ambitious but a workable 'low-gain fusion power amplifier', based on proven technologies and concepts. The aim of the Migma Program of Controlled Fusion is a small (10-15 liters) fusion power source based on colliding beams instead of plasma or laser heating. Its scientific and technological 'philosophy' is radically different from that of the governmental fusion programs of the USA and USSR. Migmacell uses radiation-free fuels, ('advanced fuels'), rather than tritium. Economic projections show that such a smaller power cell can be econonomically competitive in spite of its low power gain, because it can be mass produced. Power stations could be made either large or small and the power transmission and distribution pattern in the nation would change. An interspersion of energy resources would result. Minifusion opens the possibility to smaller countries (and medium size institutions of large countries), for participation in fusion research; this resource of research talent is presently excluded from fusion by the high cost of the mainline governmental research (over $ 200 million for one experimental fusion device, as compared to $ 1 million for migmacell). The time-scale for obtaining experimental results is reduced from decades to years. Experimental accomplishments to date and the further research needed, are presented. (orig.) [de

Cold nuclear fusion device

International Nuclear Information System (INIS)

Ogino, Shinji.

1991-01-01

Selection of cathode material is a key to the attainment of cold nuclear fusion. However, there are only few reports on the cathode material at present and an effective development has been demanded. The device comprises an anode and a cathode and an electrolytic bath having metal salts dissolved therein and containing heavy water in a glass container. The anode is made of gold or platinum and the cathode is made of metals of V, Sr, Y, Nb, Hf or Ta, and a voltage of 3-25V is applied by way of a DC power source between them. The metal comprising V, Sr, Y, Nb, Hf or Ta absorbs deuterium formed by electrolysis of heavy water effectively to cause nuclear fusion reaction at substantially the same frequency and energy efficiency as palladium and titanium. Accordingly, a cold nuclear fusion device having high nuclear fusion generation frequency can be obtained. (N.H.)

High-resolution Tangential AXUV Arrays for Radiated Power Density Measurements on NSTX-U

Energy Technology Data Exchange (ETDEWEB)

Delgado-Aparicio, L [PPPL; Bell, R E [PPPL; Faust, I [MIT; Tritz, K [The Johns Hopkins University, Baltimore, MD, 21209, USA; Diallo, A [PPPL; Gerhardt, S P [PPPL; Kozub, T A [PPPL; LeBlanc, B P [PPPL; Stratton, B C [PPPL

2014-07-01

Precise measurements of the local radiated power density and total radiated power are a matter of the uttermost importance for understanding the onset of impurity-induced instabilities and the study of particle and heat transport. Accounting of power balance is also needed for the understanding the physics of various divertor con gurations for present and future high-power fusion devices. Poloidal asymmetries in the impurity density can result from high Mach numbers and can impact the assessment of their flux-surface-average and hence vary the estimates of P[sub]rad (r, t) and (Z[sub]eff); the latter is used in the calculation of the neoclassical conductivity and the interpretation of non-inductive and inductive current fractions. To this end, the bolometric diagnostic in NSTX-U will be upgraded, enhancing the midplane coverage and radial resolution with two tangential views, and adding a new set of poloidally-viewing arrays to measure the 2D radiation distribution. These systems are designed to contribute to the near- and long-term highest priority research goals for NSTX-U which will integrate non-inductive operation at reduced collisionality, with high-pressure, long energy-confinement-times and a divertor solution with metal walls.

Frontiers in pulse-power-based high energy density plasma physics and its applications

International Nuclear Information System (INIS)

Horioka, Kazuhiko

2008-03-01

The papers in this volume of report were presented at the Symposium on Frontiers in Pulse-power-based High Energy Density Physics' held by National Institute for Fusion Science. The topics include the present status of high energy density plasma researches, extreme ultraviolet sources, intense radiation sources, high power ion beams, and R and D of related pulse power technologies. The 13 of the presented papers are indexed individually. (J.P.N.)

Frontiers of particle beam and high energy density plasma science using pulse power technology

International Nuclear Information System (INIS)

Masugata, Katsumi

2011-04-01

The papers presented at the symposium on “Frontiers of Particle Beam and High Energy Density Plasma Science using Pulse Power Technology” held in November 20-21, 2009 at National Institute for Fusion Science are collected. The papers reflect the present status and resent progress in the experiment and theoretical works on high power particle beams and high energy density plasmas produced by pulsed power technology. (author)

A conceptual fusion reactor based on the high-plasma-density Z-pinch

International Nuclear Information System (INIS)

Hartman, C.W.; Carlson, G.; Hoffman, M.; Werner, R.

1977-01-01

Conceptual DT and DD fusion reactors are discussed based on magnetic confinement with the high-plasma-density Z-pinch. The reactor concepts have no ''first wall'', the fusion neutrons and plasma energy being absorbed directly into a surrounding lithium vortex blanket. Efficient systems with low re-circulated power are projected, based on a flow-through pinch cycle for which overall Q values can approach 10. The conceptual reactors are characterized by simplicity, small minimum size (100MW(e)) and by the potential for minimal radioactivity hazards. (author)

Fusion-power demonstration

International Nuclear Information System (INIS)

Henning, C.D.; Logan, B.G.; Carlson, G.A.; Neef, W.S.; Moir, R.W.; Campbell, R.B.; Botwin, R.; Clarkson, I.R.; Carpenter, T.J.

1983-01-01

As a satellite to the MARS (Mirror Advanced Reactor Study) a smaller, near-term device has been scoped, called the FPD (Fusion Power Demonstration). Envisioned as the next logical step toward a power reactor, it would advance the mirror fusion program beyond MFTF-B and provide an intermediate step toward commercial fusion power. Breakeven net electric power capability would be the goal such that no net utility power would be required to sustain the operation. A phased implementation is envisioned, with a deuterium checkout first to verify the plasma systems before significant neutron activation has occurred. Major tritium-related facilities would be installed with the second phase to produce sufficient fusion power to supply the recirculating power to maintain the neutral beams, ECRH, magnets and other auxiliary equipment

Fusion power demonstration

International Nuclear Information System (INIS)

Henning, C.D.; Logan, B.G.

1983-01-01

As a satellite to the MARS (Mirror Advanced Reactor Study) a smaller, near-term device has been scoped, called the FPD (Fusion Power Demonstration). Envisioned as the next logical step toward a power reactor, it would advance the mirror fusion program beyond MFTF-B and provide an intermediate step toward commercial fusion power. Breakeven net electric power capability would be the goal such that no net utility power would be required to sustain the operation. A phased implementation is envisioned, with a deuterium checkout first to verify the plasma systems before significant neutron activation has occurred. Major tritium-related facilities would be installed with the second phase to produce sufficient fusion power to supply the recirculating power to maintain the neutral beams, ECRH, magnets and other auxiliary equipment

Dense Plasma Focus - From Alternative Fusion Source to Versatile High Energy Density Plasma Source for Plasma Nanotechnology

Science.gov (United States)

Rawat, R. S.

2015-03-01

The dense plasma focus (DPF), a coaxial plasma gun, utilizes pulsed high current electrical discharge to heat and compress the plasma to very high density and temperature with energy densities in the range of 1-10 × 1010 J/m3. The DPF device has always been in the company of several alternative magnetic fusion devices as it produces intense fusion neutrons. Several experiments conducted on many different DPF devices ranging over several order of storage energy have demonstrated that at higher storage energy the neutron production does not follow I4 scaling laws and deteriorate significantly raising concern about the device's capability and relevance for fusion energy. On the other hand, the high energy density pinch plasma in DPF device makes it a multiple radiation source of ions, electron, soft and hard x-rays, and neutrons, making it useful for several applications in many different fields such as lithography, radiography, imaging, activation analysis, radioisotopes production etc. Being a source of hot dense plasma, strong shockwave, intense energetic beams and radiation, etc, the DPF device, additionally, shows tremendous potential for applications in plasma nanoscience and plasma nanotechnology. In the present paper, the key features of plasma focus device are critically discussed to understand the novelties and opportunities that this device offers in processing and synthesis of nanophase materials using, both, the top-down and bottom-up approach. The results of recent key experimental investigations performed on (i) the processing and modification of bulk target substrates for phase change, surface reconstruction and nanostructurization, (ii) the nanostructurization of PLD grown magnetic thin films, and (iii) direct synthesis of nanostructured (nanowire, nanosheets and nanoflowers) materials using anode target material ablation, ablated plasma and background reactive gas based synthesis and purely gas phase synthesis of various different types of

Dense Plasma Focus - From Alternative Fusion Source to Versatile High Energy Density Plasma Source for Plasma Nanotechnology

International Nuclear Information System (INIS)

Rawat, R S

2015-01-01

The dense plasma focus (DPF), a coaxial plasma gun, utilizes pulsed high current electrical discharge to heat and compress the plasma to very high density and temperature with energy densities in the range of 1-10 × 10 10 J/m 3 . The DPF device has always been in the company of several alternative magnetic fusion devices as it produces intense fusion neutrons. Several experiments conducted on many different DPF devices ranging over several order of storage energy have demonstrated that at higher storage energy the neutron production does not follow I 4 scaling laws and deteriorate significantly raising concern about the device's capability and relevance for fusion energy. On the other hand, the high energy density pinch plasma in DPF device makes it a multiple radiation source of ions, electron, soft and hard x-rays, and neutrons, making it useful for several applications in many different fields such as lithography, radiography, imaging, activation analysis, radioisotopes production etc. Being a source of hot dense plasma, strong shockwave, intense energetic beams and radiation, etc, the DPF device, additionally, shows tremendous potential for applications in plasma nanoscience and plasma nanotechnology. In the present paper, the key features of plasma focus device are critically discussed to understand the novelties and opportunities that this device offers in processing and synthesis of nanophase materials using, both, the top-down and bottom-up approach. The results of recent key experimental investigations performed on (i) the processing and modification of bulk target substrates for phase change, surface reconstruction and nanostructurization, (ii) the nanostructurization of PLD grown magnetic thin films, and (iii) direct synthesis of nanostructured (nanowire, nanosheets and nanoflowers) materials using anode target material ablation, ablated plasma and background reactive gas based synthesis and purely gas phase synthesis of various different types of

U.S. Heavy Ion Beam Research for High Energy Density Physics Applications and Fusion

International Nuclear Information System (INIS)

Davidson, R.C.; Logan, B.G.; Barnard, J.J.; Bieniosek, F.M.; Briggs, R.J.

2005-01-01

Key scientific results from recent experiments, modeling tools, and heavy ion accelerator research are summarized that explore ways to investigate the properties of high energy density matter in heavy-ion-driven targets, in particular, strongly-coupled plasmas at 0.01 to 0.1 times solid density for studies of warm dense matter, which is a frontier area in high energy density physics. Pursuit of these near-term objectives has resulted in many innovations that will ultimately benefit heavy ion inertial fusion energy. These include: neutralized ion beam compression and focusing, which hold the promise of greatly improving the stage between the accelerator and the target chamber in a fusion power plant; and the Pulse Line Ion Accelerator (PLIA), which may lead to compact, low-cost modular linac drivers

Simulation study of a high power density rectenna array for biomedical implantable devices

Science.gov (United States)

Day, John; Yoon, Hargsoon; Kim, Jaehwan; Choi, Sang H.; Song, Kyo D.

2016-04-01

The integration of wireless power transmission devices using microwaves into the biomedical field is close to a practical reality. Implanted biomedical devices need a long lasting power source or continuous power supply. Recent development of high efficiency rectenna technology enables continuous power supply to these implanted devices. Due to the size limit of most of medical devices, it is imperative to minimize the rectenna as well. The research reported in this paper reviews the effects of close packing the rectenna elements which show the potential of directly empowering the implanted devices, especially within a confined area. The rectenna array is tested in the X band frequency range.

Prospects of High Temperature Superconductors for fusion magnets and power applications

International Nuclear Information System (INIS)

Fietz, Walter H.; Barth, Christian; Drotziger, Sandra; Goldacker, Wilfried; Heller, Reinhard; Schlachter, Sonja I.; Weiss, Klaus-Peter

2013-01-01

Highlights: • An overview of HTS application in fusion is given. • BSCCO application for current leads is discussed. • Several approaches to come to a high current HTS cable are shown. • Open issues and benefits of REBCO high current HTS cables are discussed. -- Abstract: During the last few years, progress in the field of second-generation High Temperature Superconductors (HTS) was breathtaking. Industry has taken up production of long length coated REBCO conductors with reduced angular dependency on external magnetic field and excellent critical current density jc. Consequently these REBCO tapes are used more and more in power application. For fusion magnets, high current conductors in the kA range are needed to limit the voltage during fast discharge. Several designs for high current cables using High Temperature Superconductors have been proposed. With the REBCO tape performance at hand, the prospects of fusion magnets based on such high current cables are promising. An operation at 4.5 K offers a comfortable temperature margin, more mechanical stability and the possibility to reach even higher fields compared to existing solutions with Nb 3 Sn which could be interesting with respect to DEMO. After a brief overview of HTS use in power application the paper will give an overview of possible use of HTS material for fusion application. Present high current HTS cable designs are reviewed and the potential using such concepts for future fusion magnets is discussed

Methods to enhance blanket power density in low-power fusion devices

International Nuclear Information System (INIS)

Hsu, P.Y.; Miller, L.G.; Bohn, T.S.; Deis, G.A.; Longhurst, G.R.; Masson, L.S.; Wessol, D.E.; Abdou, M.A.

1982-06-01

The overall objective of this task is to investigate the extent to which the power density in the FED breeder blanket test modules can be enhanced by artificial means. Assuming a viable approach can be developed, it will allow testing of advanced reactor blanket modules on INTOR at representative conditions. The tentative approach adopted for this task consists of three parts. First, the requirements for augmented heating of the test module are outlined for different applications of interest. Second, methods are identified which have potential for augmenting the heating power in a test module, and this list of methods is narrowed to those which appear to be most useful. Finally, these methods are examined in more detail to determine the practical benefits of employing each

Progress in high gain inertial confinement fusion

International Nuclear Information System (INIS)

Sun Jingwen

2001-01-01

The author reviews the progress in laboratory high gain inertial confinement fusion (ICF), including ICF capsule physics, high-energy-density science, inertial fusion energy, the National Ignition Facility (NIF) and its design of ignition targets and the peta watt laser breakthrough. High power laser, particle beam, and pulsed power facilities around the world have established the new laboratory field of high-energy- density plasma physics and have furthered development of inertial fusion. New capabilities such as those provided by high-brightness peta watt lasers have enabled the study of matter feasible in conditions previously unachievable on earth. Science and technology developed in inertial fusion research have found near-term commercial use and have enabled steady progress toward the goal of fusion ignition and high gain in the laboratory, and have opened up new fields of study for the 21 st century

Fusion Power measurement at ITER

Energy Technology Data Exchange (ETDEWEB)

Bertalot, L.; Barnsley, R.; Krasilnikov, V.; Stott, P.; Suarez, A.; Vayakis, G.; Walsh, M. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France)

2015-07-01

Nuclear fusion research aims to provide energy for the future in a sustainable way and the ITER project scope is to demonstrate the feasibility of nuclear fusion energy. ITER is a nuclear experimental reactor based on a large scale fusion plasma (tokamak type) device generating Deuterium - Tritium (DT) fusion reactions with emission of 14 MeV neutrons producing up to 700 MW fusion power. The measurement of fusion power, i.e. total neutron emissivity, will play an important role for achieving ITER goals, in particular the fusion gain factor Q related to the reactor performance. Particular attention is given also to the development of the neutron calibration strategy whose main scope is to achieve the required accuracy of 10% for the measurement of fusion power. Neutron Flux Monitors located in diagnostic ports and inside the vacuum vessel will measure ITER total neutron emissivity, expected to range from 1014 n/s in Deuterium - Deuterium (DD) plasmas up to almost 10{sup 21} n/s in DT plasmas. The neutron detection systems as well all other ITER diagnostics have to withstand high nuclear radiation and electromagnetic fields as well ultrahigh vacuum and thermal loads. (authors)

Managing fusion high-level waste-A strategy for burning the long-lived products in fusion devices

International Nuclear Information System (INIS)

El-Guebaly, L.A.

2006-01-01

Fusion devices appear to be a viable option for burning their own high-level waste (HLW). We propose a novel strategy to eliminate (or minimize) the HLW generated by fusion systems. The main source of the fusion HLW includes the structural and recycled materials, refractory metals, and liquid breeders. The basic idea involves recycling and reprocessing the waste, separating the long-lived radionuclides from the bulk low-level waste, and irradiating the limited amount of HLW in a specially designed module to transmute the long-lived products into short-lived radioisotopes or preferably, stable elements. The potential performance of the new concept seems promising. Our analysis indicated moderate to excellent transmutation rates could be achieved in advanced fusion designs. Successive irradiation should burn the majority of the HLW. The figures of merit for the concept relate to the HLW burn-up fraction, neutron economy, and impact on tritium breeding. Hopefully, the added design requirements could be accommodated easily in fusion power plants and the cost of the proposed system would be much less than disposal in a deep geological HLW repository. Overall, this innovative approach offers benefits to fusion systems and helps earn public acceptance for fusion as a HLW-free source of clean nuclear energy

Pulsed power drivers for ICF and high energy density physics

International Nuclear Information System (INIS)

Ramirez, J.J.; Matzen, M.K.; McDaniel, D.H.

1995-01-01

Nanosecond Pulsed Power Science and Technology has its origins in the 1960s and over the past decade has matured into a flexible and robust discipline capable of addressing key physics issues of importance to ICF and high Energy Density Physics. The major leverage provided by pulsed power is its ability to generate and deliver high energy and high power at low cost and high efficiency. A low-cost, high-efficiency driver is important because of the very large capital investment required for multi-megajoule ignition-class systems. High efficiency is of additional importance for a commercially viable inertial fusion energy option. Nanosecond pulsed power has been aggressively and successfully developed at Sandia over the past twenty years. This effort has led to the development of unique multi-purpose facilities supported by highly capable diagnostic, calculational and analytic capabilities. The Sandia Particle-beam Fusion Program has evolved as part of an integrated national ICF Program. It applies the low-cost, high-efficiency leverage provided by nanosecond pulsed power systems to the longer-term goals of the national program, i.e., the Laboratory Microfusion Facility and Inertial Fusion Energy. A separate effort has led to the application of nanosecond pulsed power to the generation of intense, high-energy laboratory x-ray sources for application to x-ray laser and radiation effects science research. Saturn is the most powerful of these sources to date. It generates ∼500 kilojoules of x-rays from a magnetically driven implosion (Z-pinch). This paper describes results of x-ray physics experiments performed on Saturn, plans for a new Z-pinch drive capability for PBFA-II, and a design concept for the proposed ∼15 MJ Jupiter facility. The opportunities for ICF-relevant research using these facilities will also be discussed

Flexible asymmetric supercapacitors with high energy and high power density in aqueous electrolytes

Science.gov (United States)

Cheng, Yingwen; Zhang, Hongbo; Lu, Songtao; Varanasi, Chakrapani V.; Liu, Jie

2013-01-01

Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO2, activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s-1 to 500 mV s-1. Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg-1) under high power density (7.8 kW kg-1) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required.Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO2, activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of

High-energy-density physics researches based on pulse power technology

International Nuclear Information System (INIS)

Horioka, Kazuhiko; Nakajima, Mitsuo; Kawamura, Tohru; Sasaki, Toru; Kondo, Kotaro; Yano, Yuuri

2006-01-01

Plasmas driven by pulse power device are of interest, concerning the researches on high-energy-density (HED) physics. Dense plasmas are produced using pulse power driven exploding discharges in water. Experimental results show that the wire plasma is tamped and stabilized by the surrounding water and it evolves through a strongly coupled plasma state. A shock-wave-heated, high temperature plasma is produced in a compact pulse power device. Experimental results show that strong shock waves can be produced in the device. In particular, at low initial pressure condition, the shock Mach number reaches 250 and this indicates that the shock heated region is dominated by radiation processes. (author)

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.

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.

High density, high magnetic field concepts for compact fusion reactors

International Nuclear Information System (INIS)

Perkins, L.J.

1996-01-01

One rather discouraging feature of our conventional approaches to fusion energy is that they do not appear to lend themselves to a small reactor for developmental purposes. This is in contrast with the normal evolution of a new technology which typically proceeds to a full scale commercial plant via a set of graduated steps. Accordingly' several concepts concerned with dense plasma fusion systems are being studied theoretically and experimentally. A common aspect is that they employ: (a) high to very high plasma densities (∼10 16 cm -3 to ∼10 26 cm -3 ) and (b) magnetic fields. If they could be shown to be viable at high fusion Q, they could conceivably lead to compact and inexpensive commercial reactors. At least, their compactness suggests that both proof of principle experiments and development costs will be relatively inexpensive compared with the present conventional approaches. In this paper, the following concepts are considered: (1) The staged Z-pinch, (2) Liner implosion of closed-field-line configurations, (3) Magnetic ''fast'' ignition of inertial fusion targets, (4) The continuous flow Z-pinch

Design, construction, and characterization of high-performance membrane fusion devices with target-selectivity.

Science.gov (United States)

Kashiwada, Ayumi; Yamane, Iori; Tsuboi, Mana; Ando, Shun; Matsuda, Kiyomi

2012-01-31

Membrane fusion proteins such as the hemagglutinin glycoprotein have target recognition and fusion accelerative domains, where some synergistically working elements are essential for target-selective and highly effective native membrane fusion systems. In this work, novel membrane fusion devices bearing such domains were designed and constructed. We selected a phenylboronic acid derivative as a recognition domain for a sugar-like target and a transmembrane-peptide (Leu-Ala sequence) domain interacting with the target membrane, forming a stable hydrophobic α-helix and accelerating the fusion process. Artificial membrane fusion behavior between the synthetic devices in which pilot and target liposomes were incorporated was characterized by lipid-mixing and inner-leaflet lipid-mixing assays. Consequently, the devices bearing both the recognition and transmembrane domains brought about a remarkable increase in the initial rate for the membrane fusion compared with the devices containing the recognition domain alone. In addition, a weakly acidic pH-responsive device was also constructed by replacing three Leu residues in the transmembrane-peptide domain by Glu residues. The presence of Glu residues made the acidic pH-dependent hydrophobic α-helix formation possible as expected. The target-selective liposome-liposome fusion was accelerated in a weakly acidic pH range when the Glu-substituted device was incorporated in pilot liposomes. The use of this pH-responsive device seems to be a potential strategy for novel applications in a liposome-based delivery system. © 2011 American Chemical Society

Open-ended fusion devices and reactors

International Nuclear Information System (INIS)

Kawabe, T.; Nariai, H.

1983-01-01

Conceptual design studies on fusion reactors based upon open-ended confinement schemes, such as the tandem mirror and rf plugged cusp, have been carried out in Japan. These studies may be classified into two categories: near-term devices (Fusion Engineering Test Facility), and long-term fusion power recators. In the first category, a two-component cusp neutron source was proposed. In the second category, the GAMMA-R, a tandem-mirror power reactor, and the RFC-R, an axisymetric mirror and cusp, reactor studies are being conducted at the University of Tsukuba and the Institute of Plasma Physics. Mirror Fusion Engineering Facility parameters and a schematic are shown. The GAMMA-R central-cell design schematic is also shown

Advanced High Voltage Power Device Concepts

CERN Document Server

Baliga, B Jayant

2012-01-01

Advanced High Voltage Power Device Concepts describes devices utilized in power transmission and distribution equipment, and for very high power motor control in electric trains and steel-mills. Since these devices must be capable of supporting more than 5000-volts in the blocking mode, this books covers operation of devices rated at 5,000-V, 10,000-V and 20,000-V. Advanced concepts (the MCT, the BRT, and the EST) that enable MOS-gated control of power thyristor structures are described and analyzed in detail. In addition, detailed analyses of the silicon IGBT, as well as the silicon carbide MOSFET and IGBT, are provided for comparison purposes. Throughout the book, analytical models are generated to give a better understanding of the physics of operation for all the structures. This book provides readers with: The first comprehensive treatment of high voltage (over 5000-volts) power devices suitable for the power distribution, traction, and motor-control markets;  Analytical formulations for all the device ...

Minimization of the external heating power by long fusion power rise-up time for self-ignition access in the helical reactor FFHR2m

International Nuclear Information System (INIS)

Mitarai, O.; Sagara, A.; Chikaraishi, H.; Imagawa, S.; Shishkin, A.A.; Motojima, O.

2006-10-01

Minimization of the external heating power to access self-ignition is advantageous to increase the reactor design flexibility and to reduce the capital and operating costs of the plasma heating device in a helical reactor. In this work we have discovered that a larger density limit leads to a smaller value of the required confinement enhancement factor, lower density limit margin reduces the external heating power, and over 300 s of the fusion power rise-up time makes it possible to reach a minimized heating power. While the fusion power rise-up time in a tokamak is limited by the OH transformer flux or the current drive capability, any fusion power rise-up time can be employed in a helical reactor for reducing the thermal stresses of the blanket and shields, because the confinement field is generated by the external helical coils. (author)

A High Power Density Integrated Charger for Electric Vehicles with Active Ripple Compensation

OpenAIRE

Pan, Liwen; Zhang, Chengning

2015-01-01

This paper suggests a high power density on-board integrated charger with active ripple compensation circuit for electric vehicles. To obtain a high power density and high efficiency, silicon carbide devices are reported to meet the requirement of high-switching-frequency operation. An integrated bidirectional converter is proposed to function as AC/DC battery charger and to transfer energy between battery pack and motor drive of the traction system. In addition, the conventional H-bridge cir...

Performance evaluation of a high power DC-DC boost converter for PV applications using SiC power devices

Science.gov (United States)

Almasoudi, Fahad M.; Alatawi, Khaled S.; Matin, Mohammad

2016-09-01

The development of Wide band gap (WBG) power devices has been attracted by many commercial companies to be available in the market because of their enormous advantages over the traditional Si power devices. An example of WBG material is SiC, which offers a number of advantages over Si material. For example, SiC has the ability of blocking higher voltages, reducing switching and conduction losses and supports high switching frequency. Consequently, SiC power devices have become the affordable choice for high frequency and power application. The goal of this paper is to study the performance of 4.5 kW, 200 kHz, 600V DC-DC boost converter operating in continuous conduction mode (CCM) for PV applications. The switching behavior and turn on and turn off losses of different switching power devices such as SiC MOSFET, SiC normally ON JFET and Si MOSFET are investigated and analyzed. Moreover, a detailed comparison is provided to show the overall efficiency of the DC-DC boost converter with different switching power devices. It is found that the efficiency of SiC power switching devices are higher than the efficiency of Si-based switching devices due to low switching and conduction losses when operating at high frequencies. According to the result, the performance of SiC switching power devices dominate the conventional Si power devices in terms of low losses, high efficiency and high power density. Accordingly, SiC power switching devices are more appropriate for PV applications where a converter of smaller size with high efficiency, and cost effective is required.

Fusion devices

International Nuclear Information System (INIS)

Fowler, T.K.

1977-01-01

Three types of thermonuclear fusion devices currently under development are reviewed for an electric utilities management audience. Overall design features of laser fusion, tokamak, and magnetic mirror type reactors are described and illustrated. Thrusts and trends in current research on these devices that promise to improve performance are briefly reviewed. Twenty photographs and drawings are included

APEX and ALPS, high power density technology programs in the U.S

International Nuclear Information System (INIS)

Wong, C.P.C.; Berk, S.; Abdou, M.; Mattas, R.

1999-02-01

In fiscal year (FY) 1998 two new fusion technology programs were initiated in the US, with the goal of making marked progress in the scientific understanding of technologies and materials required to withstand high plasma heat flux and neutron wall loads. APEX is exploring new and revolutionary concepts that can provide the capability to extract heat efficiently from a system with high neutron and surface heat loads while satisfying all the fusion power technology requirements and achieving maximum reliability, maintainability, safety, and environmental acceptability. ALPS program is evaluating advanced concepts including liquid surface limiters and divertors on the basis of such factors as their compatibility with fusion plasma, high power density handling capabilities, engineering feasibility, lifetime, safety and R and D requirements. The APEX and ALPS are three-year programs to specify requirements and evaluate criteria for revolutionary approaches in first wall, blanket and high heat flux component applications. Conceptual design and analysis of candidate concepts are being performed with the goal of selecting the most promising first wall, blanket and high heat flux component designs that will provide the technical basis for the initiation of a significant R and D effort beginning in FY2001. These programs are also considering opportunities for international collaborations

The Roles and Developments needed for Diagnostics in the ITER Fusion Device

Energy Technology Data Exchange (ETDEWEB)

Walsh, Michael [ITER Organization, Route de Vinon-sur-Verdon - CS 90046, 13067 St Paul-lez-Durance Cedex (France)

2015-07-01

Harnessing the power from Fusion on earth is an important and challenging task. Excellent work has been carried out in this area over the years with several demonstrations of the ability to produce power. Now, a new large device is being constructed in the south of France. This is called ITER. ITER is a large-scale scientific experiment that aims to demonstrate a possibility to produce commercial energy from fusion. This project is now well underway with the many teams working on the construction and completing various aspects of the design. This device will carry up to 15 MA of plasma current and produce about 500 MW of power, 400 MW approximately in high energy neutrons. The typical temperatures of the electrons inside this device are in the region of a few hundred million Kelvin. It is maintained using a magnetic field. This device is pushing several boundaries from those currently existing. As a result of this, several technologies need to be developed or extended. This is especially true for the systems or diagnostics that measure the performance and provide the control signals for this device. A diagnostic set will be installed on the ITER machine to provide the measurements necessary to control, evaluate and optimize plasma performance in ITER and to further the understanding of plasma physics. These include amongst others, measurements of the plasma shape, temperature, density, impurity concentration, and particle and energy confinement times. The system will comprise about 45 individual measuring systems drawn from the full range of modern plasma diagnostic techniques, including magnetics, lasers, X-rays, neutron cameras, impurity monitors, particle spectrometers, radiation bolometers, pressure and gas analysis, and optical fibres. These devices will have to be made to work in the new and challenging environment inside the vacuum vessel. These systems will have to cope with a range of phenomena that extend the current knowledge in the Fusion field. One

High-density and high-ρR fuel assembly for fast-ignition inertial confinement fusion

International Nuclear Information System (INIS)

Betti, R.; Zhou, C.

2005-01-01

Scaling relations to optimize implosion parameters for fast-ignition inertial confinement fusion are derived and used to design high-gain fast-ignition targets. A method to assemble thermonuclear fuel at high densities, high ρR, and with a small-size hot spot is presented. Massive cryogenic shells can be imploded with a low implosion velocity V I on a low adiabat α using the relaxation-pulse technique. While the low V I yields a small hot spot, the low α leads to large peak values of the density and areal density. It is shown that a 750 kJ laser can assemble fuel with V I ≅1.7x10 7 cm/s, α≅0.7, ρ≅400 g/cc, ρR≅3 g/cm 2 , and a hot-spot volume of less than 10% of the compressed core. If fully ignited, this fuel assembly can produce high gains of interest to inertial fusion energy applications

Fast-imploding-linear fusion power

International Nuclear Information System (INIS)

Moses, R.W.; Krakowski, R.A.; MIller, R.L.

1978-01-01

A Fast-Liner Reactor (FLR) conceptual design is summarized. The FLR is a pulsed D-T fusion concept that envisages the implosion of a small, cylindrical (0.2-m radius, 0.2-m length), metallic shell onto an initially warm plasma to achieve net energy production by means of rapid but adiabatic compression to thermonuclear temperature. The primary purpose of this study is to examine by means of detailed computer models the physical processes and constraints which may limit this unique approach to high-density fusion power. On the basis of an optimized physics operating point, a conceptual reactor embodiment is described

High-temperature and high-power-density nanostructured thermoelectric generator for automotive waste heat recovery

International Nuclear Information System (INIS)

Zhang, Yanliang; Cleary, Martin; Wang, Xiaowei; Kempf, Nicholas; Schoensee, Luke; Yang, Jian; Joshi, Giri; Meda, Lakshmikanth

2015-01-01

Highlights: • A thermoelectric generator (TEG) is fabricated using nanostructured half-Heusler materials. • The TE unicouple devices produce superior power density above 5 W/cm"2. • A TEG system with over 1 kW power output is demonstrated by recovering automotive waste heat. - Abstract: Given increasing energy use as well as decreasing fossil fuel sources worldwide, it is no surprise that interest in promoting energy efficiency through waste heat recovery is also increasing. Thermoelectric generators (TEGs) are one of the most promising pathways for waste heat recovery. Despite recent thermoelectric efficiency improvement in nanostructured materials, a variety of challenges have nevertheless resulted in few demonstrations of these materials for large-scale waste heat recovery. Here we demonstrate a high-performance TEG by combining high-efficiency nanostructured bulk materials with a novel direct metal brazing process to increase the device operating temperature. A unicouple device generates a high power density of 5.26 W cm"−"2 with a 500 °C temperature difference between hot and cold sides. A 1 kW TEG system is experimentally demonstrated by recovering the exhaust waste heat from an automotive diesel engine. The TEG system operated with a 2.1% heat-to-electricity efficiency under the average temperature difference of 339 °C between the TEG hot- and cold-side surfaces at a 550 °C exhaust temperature. The high-performance TEG reported here open up opportunities to use TEGs for energy harvesting and power generation applications.

Inherent/passive safety in fusion power plants

International Nuclear Information System (INIS)

Piet, S.J.; Crocker, J.G.

1986-01-01

The concept of inherent or passive safety for fusion energy is explored, defined, and partially quantified. Four levels of safety assurance are defined, which range from true inherent safety to passive safety to protection via active engineered safeguard systems. Fusion has the clear potential for achieving inherent or passive safety, which should be an objective of fusion research and design. Proper material choice might lead to both inherent/passive safety and high mass power density, improving both safety and economics. When inherent or passive safety is accomplished, fusion will be well on the way to achieving its ultimate potential and to be a truly superior energy source for the future

A 380 V High Efficiency and High Power Density Switched-Capacitor Power Converter using Wide Band Gap Semiconductors

DEFF Research Database (Denmark)

Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

2018-01-01

. This paper presents such a high voltage low power switched-capacitor DC-DC converter with an input voltage upto 380 V (compatible with rectified European mains) and an output power experimentally validated up to 21.3 W. The wideband gap semiconductor devices of GaN switches and SiC diodes are combined...... to compose the proposed power stage. Their switching and loss characteristics are analyzed with transient waveforms and thermal images. Different isolated driving circuits are compared and a compact isolated halfbridge driving circuit is proposed. The full-load efficiencies of 98.3% and 97.6% are achieved......State-of-the-art switched-capacitor DC-DC power converters mainly focus on low voltage and/or high power applications. However, at high voltage and low power levels, new designs are anticipated to emerge and a power converter that has both high efficiency and high power density is highly desirable...

Design of power control system using SMES and SVC for fusion power plant

International Nuclear Information System (INIS)

Niiyama, K; Yagai, T; Tsuda, M; Hamajima, T

2008-01-01

A SMES (Superconducting Magnetic Energy Storage System) system with converter composed of self-commutated valve devices such as GTO and IGBT is available to control active and reactive power simultaneously. A SVC (Static Var Compensators) or STATCOM (Static Synchronous Compensator) is widely employed to reduce reactive power in power plants and substations. Owing to progress of power electronics technology using GTO and IGBT devices, power converters in the SMES system and the SVC can easily control power flow in few milliseconds. Moreover, since the valve devices for the SMES are equivalent to those for the SVC, the device cost must be reduced. In this paper the basic control system combined with the SMES and SVC is designed for large pulsed loads of a nuclear fusion power plant. This combined system largely expands the reactive power control region as well as the active one. The simulation results show that the combined system is effective and prospective for the nuclear fusion power plant

Power balancing of multibeam laser fusion lasers

International Nuclear Information System (INIS)

Seka, W.; Morse, S.; Letzring, S.; Kremens, R.; Kessler, T.J.; Jaanimagi, P.; Keck, R.; Verdon, C.; Brown, D.

1989-01-01

The success of laser fusion depends to a good degree on the ability to compress the target to very high densities of ≥1000 times liquid DT. To achieve such compressions require that the irradiation nonuniformity must not exceed ∼1% rms over the whole time of the compression, particularly during the early phases of irradiation. The stringent requirements for the irradiation uniformity for laser fusion have been known for quite some time but until recently the energy balance was mistakenly equated to power balance. The authors describe their effort on energy balance and irradiation patterns on the target. They significantly improved the laser performance with respect to overall intensity distributions on target including the implementation of distributed (random) phase plates in each high power beam. However, the slightly varying performance of the third harmonic conversion crystals in the twenty-four beams of their laser system was generally compensated for by appropriately adjusted 1.054μm input laser energy. Computational analysis of the results of the recent high density campaign are shown

Fusion by 1990: the Sandia ion beam program can do it

International Nuclear Information System (INIS)

Stevens, C.B.

1985-01-01

Recent experimental results at Sandia National Laboratories demonstrate that light ion beam accelerator devices can deliver considerably more than the power necessary for achieving high-gain fusion energy - millions of joules at power densities of 10,000 trillion watts/cm 2 . This means that commercial fusion energy with an inertial-confinement fusion device can be realized by the 1990s, despite the general curtailment of the US fusion research budget over the past eight years. Dr. J. Pace VanDevender, pulsed power sciences director at Sandia, and Professor Ravindra N. Sudan, director of the Cornell University Laboratory of Plasma Studies, discussed the experimental and theoretical advances underlying this happy prognosis at the April 17-19 conference at the Rochester University for Laser Energetics. Sudan showed that experiments with high-current ion beam pulses over the past decade have demonstrated that such pulses, instead of diffusing, tend to self-focus nonlinearly to higher power densities. Second, weak magnetic fields do not interact and change the trajectory of such high-current beam pulses. At the Rochester meeting, VanDevender reviewed experiments on Sandia's Proto I device in which 1.5 trillion watts per square centimeter were delivered to a target in May 1984. This spring, Sandia's Particle Beam Fusion Accelerator I, PBFA I, delivered an 8-trillion watt pulse onto a spot 4.0 to 4.5 millimeters in diameter. This demonstrated that the Sandia light ion beam focusing process maintains itself as the current is increased. 3 figures

High performance inertial fusion targets

International Nuclear Information System (INIS)

Nuckolls, J.H.; Bangerter, R.O.; Lindl, J.D.; Mead, W.C.; Pan, Y.L.

1977-01-01

Inertial confinement fusion (ICF) designs are considered which may have very high gains (approximately 1000) and low power requirements (<100 TW) for input energies of approximately one megajoule. These include targets having very low density shells, ultra thin shells, central ignitors, magnetic insulation, and non-ablative acceleration

Study on the impact of the engineering energy gain and the FPC mass power density on the generation cost of fusion power plant

International Nuclear Information System (INIS)

Huang Desuo; Wu Yican

2004-01-01

The impact of the engineering energy gain and the fusion-power-core (FPC) mass power density (MPD) on the generation cost of fusion power plant are analyzed based on the economic elasticity approach in this paper. From the functions describing the relationship of the generation cost with the engineering energy gain and the MPD, the elasticity coefficients of the generation cost with the engineering energy gain and the MPD have been derived respectively to analyze their sensitivity to the generation cost and the MPD to the generation cost decreases with increasing the engineering energy gain or the MPD. (authors)

Electronic DC transformer with high power density

NARCIS (Netherlands)

Pavlovský, M.

2006-01-01

This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

High performance inertial fusion targets

International Nuclear Information System (INIS)

Nuckolls, J.H.; Bangerter, R.O.; Lindl, J.D.; Mead, W.C.; Pan, Y.L.

1978-01-01

Inertial confinement fusion (ICF) target designs are considered which may have very high gains (approximately 1000) and low power requirements (< 100 TW) for input energies of approximately one megajoule. These include targets having very low density shells, ultra thin shells, central ignitors, magnetic insulation, and non-ablative acceleration

Highly efficient red electrophosphorescent devices at high current densities

International Nuclear Information System (INIS)

Wu Youzhi; Zhu Wenqing; Zheng Xinyou; Sun, Runguang; Jiang Xueyin; Zhang Zhilin; Xu Shaohong

2007-01-01

Efficiency decrease at high current densities in red electrophosphorescent devices is drastically restrained compared with that from conventional electrophosphorescent devices by using bis(2-methyl-8-quinolinato)4-phenylphenolate aluminum (BAlq) as a hole and exciton blocker. Ir complex, bis(2-(2'-benzo[4,5-α]thienyl) pyridinato-N,C 3' ) iridium (acetyl-acetonate) is used as an emitter, maximum external quantum efficiency (QE) of 7.0% and luminance of 10000cd/m 2 are obtained. The QE is still as high as 4.1% at higher current density J=100mA/cm 2 . CIE-1931 co-ordinates are 0.672, 0.321. A carrier trapping mechanism is revealed to dominate in the process of electroluminescence

Improved zero dimensional model of a reversed field pinch fusion device

International Nuclear Information System (INIS)

Haynes, K.E.

1987-01-01

A zero-dimensional model has been developed which accurately predicts conditions observed during several runs of the ZT-40M reversed field pinch fusion device at Los Alamos National Laboratory. The model is based on a physical model developed by E.H. Klevans at Penn State University. Improvements made to this model included the use of coronal non-equilibrium equations for predicting impurity effects, the inclusion of an exponentially decaying ion heating term, and the relaxation of the assumption that ion and electron densities are equal in the device. The model has been used to simulate ZT-40M in both flat-top and slowly ramped current modes. Using experimentally measured density and current evolutions, the model accurately predicts observed tau/sub E/, β/sub Θ/, T/sub e/, T/sub i/, Z/sub eff/, and radiated power. The continuing goal of this work is to predict conditions in the ZT-H device, which is under construction. 28 refs., 18 figs

Research on high energy density plasmas and applications

International Nuclear Information System (INIS)

1999-01-01

Recently, technologies on lasers, accelerators, and pulse power machines have been significantly advanced and input power density covers the intensity range from 10 10 W/cm 2 to higher than 10 20 W/cm 2 . As the results, high pressure gas and solid targets can be heated up to very high temperature to create hot dense plasmas which have never appeared on the earth. The high energy density plasmas opened up new research fields such as inertial confinement fusion, high brightness X-ray radiation sources, interiors of galactic nucleus,supernova, stars and planets, ultra high pressure condensed matter physics, plasma particle accelerator, X-ray laser, and so on. Furthermore, since these fields are intimately connected with various industrial sciences and technologies, the high energy density plasma is now studied in industries, government institutions, and so on. This special issue of the Journal of Plasma Physics and Nuclear Fusion Research reviews the high energy density plasma science for the comprehensive understanding of such new fields. In May, 1998, the review committee for investigating the present status and the future prospects of high energy density plasma science was established in the Japan Society of Plasma Science and Nuclear Fusion Research. We held three committee meetings to discuss present status and critical issues of research items related to high energy density plasmas. This special issue summarizes the understandings of the committee. This special issue consists of four chapters: They are Chapter 1: Physics important in the high energy density plasmas, Chapter 2: Technologies related to the plasma generation; drivers such as lasers, pulse power machines, particle beams and fabrication of various targets, Chapter 3: Plasma diagnostics important in high energy density plasma experiments, Chapter 4: A variety of applications of high energy density plasmas; X-ray radiation, particle acceleration, inertial confinement fusion, laboratory astrophysics

High Power Density Power Electronic Converters for Large Wind Turbines

DEFF Research Database (Denmark)

Senturk, Osman Selcuk

. For these VSCs, high power density is required due to limited turbine nacelle space. Also, high reliability is required since maintenance cost of these remotely located wind turbines is quite high and these turbines operate under harsh operating conditions. In order to select a high power density and reliability......In large wind turbines (in MW and multi-MW ranges), which are extensively utilized in wind power plants, full-scale medium voltage (MV) multi-level (ML) voltage source converters (VSCs) are being more preferably employed nowadays for interfacing these wind turbines with electricity grids...... VSC solution for wind turbines, first, the VSC topology and the switch technology to be employed should be specified such that the highest possible power density and reliability are to be attained. Then, this qualitative approach should be complemented with the power density and reliability...

Electric power from laser fusion: the HYLIFE concept

International Nuclear Information System (INIS)

Monsler, M.; Blink, J.; Hovingh, J.; Meier, W.; Walker, P.; Maniscalco, J.

1978-06-01

A high yield lithium injection fusion energy chamber is described which can conceptually be operated with pulsed yields of several thousand megajoules a few times a second, using less than one percent of the gross thermal power to circulate the lithium. Because a one meter thick blanket of lithium protects the structure, no first wall replacement is envisioned for the life of the power plant. The induced radioactivity is reduced by an order of magnitude over solid blanket concepts. The design calls for the use of common ferritic steels and a power density approaching that of a LWR, promising shortened development times over other fusion concepts and reactor vessel costs comparable to a LMFBR

High-field, high-density tokamak power reactor

International Nuclear Information System (INIS)

Cohn, D.R.; Cook, D.L.; Hay, R.D.; Kaplan, D.; Kreischer, K.; Lidskii, L.M.; Stephany, W.; Williams, J.E.C.; Jassby, D.L.; Okabayashi, M.

1977-11-01

A conceptual design of a compact (R 0 = 6.0 m) high power density (average P/sub f/ = 7.7 MW/m 3 ) tokamak demonstration power reactor has been developed. High magnetic field (B/sub t/ = 7.4 T) and moderate elongation (b/a = 1.6) permit operation at the high density (n(0) approximately 5 x 10 14 cm -3 ) needed for ignition in a relatively small plasma, with a spatially-averaged toroidal beta of only 4%. A unique design for the Nb 3 Sn toroidal-field magnet system reduces the stress in the high-field trunk region, and allows modularization for simpler disassembly. The modest value of toroidal beta permits a simple, modularized plasma-shaping coil system, located inside the TF coil trunk. Heating of the dense central plasma is attained by the use of ripple-assisted injection of 120-keV D 0 beams. The ripple-coil system also affords dynamic control of the plasma temperature during the burn period. A FLIBE-lithium blanket is designed especially for high-power-density operation in a high-field environment, and gives an overall tritium breeding ratio of 1.05 in the slowly pumped lithium

Management of water leaks on Tore Supra actively cooled fusion device

International Nuclear Information System (INIS)

Hatchressian, J.C.; Gargiulo, L.; Samaille, F.; Soler, B.

2005-01-01

Up to now, Tore Supra is the only fusion device fully equipped with actively cooled Plasma Facing Components (PFCs). In case of abnormal events during a plasma discharge, the PFCs could be submitted to a transient high power density (run away electrons) or to a continuous phenomena as local thermal flux induced by trapped suprathermal electrons or ions). It could lead to a degradation of the PFC integrity and in the worst case to a water leak occurrence. Such water leak has important consequence on the tokamak operation that concerns PFCs themselves, monitoring equipment located in the vacuum vessel or connected to the ports as RF antennas, diagnostics or pumping systems. Following successive water leak events (the most important water leak, that occurred in September 2002, is described in the paper), a large feedback experience has been gained on Tore supra since more than 15 years that could be useful to actively cooled next devices as W7X and ITER. (authors)

Optimization of fusion power density in the two-energy-component tokamak reactor

International Nuclear Information System (INIS)

Jassby, D.L.

1974-10-01

The optimal plasma conditions for maximizing fusion power density P/sub f/ in a beam-driven D--T tokamak reactor (TCT) are considered. Given T/sub e/ = T/sub i/ and fixed total plasma pressure, there is an optimal n/sub e/tau/sub E/ for maximizing P/sub f/, viz. n/sub e/tau/sub E/ = 4 x 10 12 to 2 x 10 13 cm -3 sec for T/sub e/ = 3--15 keV and 200-keV D beams. The corresponding anti GAMMA equals (beam pressure/bulk-plasma pressure) is 0.96 to 0.70. P/sub fmax/ increases as T/sub e/ is reduced and can be an order of magnitude larger than the maximum P/sub f/ of a thermal reactor of the same beta, at any temperature. A lower practical limit to T/sub e/ may be set by requiring a minimum beam power multiplication Q/sub b/. For the purpose of fissile breeding, the minimum Q/sub b/ approximately 0.6, requiring T/sub e/ greater than or equal to 3 keV if Z = 1. The optimal operating conditions of a TCT for obtaining P/sub fmax/ are considerably different from those for enhancing Q/sub b/. Maximizing P/sub f/ requires restricting both T/sub e/ and n/sub e/tau/sub E/, maintaining a bulk plasma markedly enriched in tritium, and spoiling confinement of fusion alphas. Considerable impurity content can be tolerated without seriously degrading P/sub fmax/, and high-Z impurity radiation may be useful for regulating tau/sub E/. (auth)

High density linear systems for fusion power

International Nuclear Information System (INIS)

Ellis, W.R.; Krakowski, R.A.

1975-01-01

The physics and technological limitations and uncertainties associated with the linear theta pinch are discussed in terms of a generalized energy balance, which has as its basis the ratio (Q/sub E/) of total electrical energy generated to net electrical energy consumed. Included in this total is the virtual energy of bred fissile fuel, if a hybrid blanket is used, as well as the actual of real energy deposited in the blanket by the fusion neutron. The advantages and disadvantages of the pulsed operation demanded by the linear theta pinch are also discussed

Philosophy and physics of predemonstration fusion devices

International Nuclear Information System (INIS)

Clarke, J.F.

1976-01-01

A PDFD will operate in the 1980's and must provide the plasma and plasma support technology information necessary to warrant design, construction, and operation of succeeding experimental power reactors and then the demonstration plant. The PDFD must be prototypical of economic fusion devices to justify its cost. Therefore, development of the fusion core will be the focus of the PDFD. The physics performance, power production objectives, and characteristics of the PDFD, and their relationship to the research and development needs to achieve them are outlined. The design criteria for a PDFD which satisfied these constraints will be established

Transmission line pulse system for avalanche characterization of high power semiconductor devices

Science.gov (United States)

Riccio, Michele; Ascione, Giovanni; De Falco, Giuseppe; Maresca, Luca; De Laurentis, Martina; Irace, Andrea; Breglio, Giovanni

2013-05-01

Because of the increasing in power density of electronic devices for medium and high power application, reliabilty of these devices is of great interest. Understanding the avalanche behaviour of a power device has become very important in these last years because it gives an indication of the maximum energy ratings which can be seen as an index of the device ruggedness. A good description of this behaviour is given by the static IV blocking characteristc. In order to avoid self heating, very relevant in high power devices, very short pulses of current have to be used, whose value can change from few milliamps up to tens of amps. The most used method to generate short pulses is the TLP (Transmission Line Pulse) test, which is based on charging the equivalent capacitance of a transmission line to high value of voltage and subsequently discharging it onto a load. This circuit let to obtain very short square pulses but it is mostly used for evaluate the ESD capability of semiconductor and, in this environment, it generates pulses of low amplitude which are not high enough to characterize the avalanche behaviour of high power devices . Advanced TLP circuit able to generate high current are usually very expensive and often suffer of distorption of the output pulse. In this article is proposed a simple, low cost circuit, based on a boosted-TLP configuration, which is capable to produce very square pulses of about one hundreds of nanosecond with amplitude up to some tens of amps. A prototype is implemented which can produce pulses up to 20A of amplitude with 200 ns of duration which can characterize power devices up to 1600V of breakdown voltage. Usage of microcontroller based logic make the circuit very flexible. Results of SPICE simulation are provided, together with experimental results. To prove the effectiveness of the circuit, the I-V blocking characteristics of two commercial devices, namely a 600V PowerMOS and a 1200V Trench-IGBT, are measured at different

The ITER fusion reactor and its role in the development of a fusion power plant

International Nuclear Information System (INIS)

McLean, A.

2002-01-01

Energy from nuclear fusion is the future source of sustained, full life-cycle environmentally benign, intrinsically safe, base-load power production. The nuclear fusion process powers our sun, innumerable other stars in the sky, and some day, it will power the Earth, its cities and our homes. The International Thermonuclear Experimental Reactor, ITER, represents the next step toward fulfilling that promise. ITER will be a test bed for key steppingstones toward engineering feasibility of a demonstration fusion power plant (DEMO) in a single experimental step. It will establish the physics basis for steady state Tokamak magnetic containment fusion reactors to follow it, exploring ion temperature, plasma density and containment time regimes beyond the breakeven power condition, and culminating in experimental fusion self-ignition. (author)

Generation of high-power-density atmospheric pressure plasma with liquid electrodes

International Nuclear Information System (INIS)

Dong Lifang; Mao Zhiguo; Yin Zengqian; Ran Junxia

2004-01-01

We present a method for generating atmospheric pressure plasma using a dielectric barrier discharge reactor with two liquid electrodes. Four distinct kinds of discharge, including stochastic filaments, regular square pattern, glow-like discharge, and Turing stripe pattern, are observed in argon with a flow rate of 9 slm. The electrical and optical characteristics of the device are investigated. Results show that high-power-density atmospheric pressure plasma with high duty ratio in space and time can be obtained. The influence of wall charges on discharge power and duty ratio has been discussed

Physics of laser fusion. Volume III. High-power pulsed lasers

International Nuclear Information System (INIS)

Holzrichter, J.F.; Eimerl, D.; George, E.V.; Trenholme, J.B.; Simmons, W.W.; Hunt, J.T.

1982-09-01

High-power pulsed lasers can deliver sufficient energy on inertial-confinement fusion (ICF) time scales (0.1 to 10 ns) to heat and compress deuterium-tritium fuel to fusion-reaction conditions. Several laser systems have been examined, including Nd:glass, CO 2 , KrF, and I 2 , for their ICF applicability. A great deal of developmental effort has been applied to the Nd:glass laser and the CO 2 gas laser systems; these systems now deliver > 10 4 J and 20 x 10 12 W to ICF targets. We are constructing the Nova Nd:glass laser at LLNL to provide > 100 kJ and > 100 x 10 12 W of 1-μm radiation for fusion experimentation in the mid-1980s. For ICF target gain > 100 times the laser input, we expect that the laser driver must deliver approx. 3 to 5 MJ of energy on a time scale of 10 to 20 ns. In this paper we review the technological status of fusion-laser systems and outline approaches to constructing high-power pulsed laser drivers

US Heavy Ion Beam Research for Energy Density Physics Applications and Fusion

International Nuclear Information System (INIS)

Davidson, R.C.; Logan, B.G.; Barnard, J.J.; Bieniosek, F.M.; Briggs, R.J.; Callahan D.A.; Kireeff Covo, M.; Celata, C.M.; Cohen, R.H.; Coleman, J.E.; Debonnel, C.S.; Grote, D.P.; Efthimiom, P.C.; Eylon, S.; Friedman, A.; Gilson, E.P.; Grisham, L.R.; Henestroza, E.; Kaganovich, I.D.; Kwan, J.W.; Lee, E.P.; Lee, W.W.; Leitner, M.; Lund, S.M.; Meier, W.R.; Molvik, A.W.; Olson, C.L.; Penn, G.E.; Qin, H.; Roy, P.K.; Rose, D.V.; Sefkow, A.; Seidl, P.A.; Sharp, W.M.; Startsev, E.A.; Tabak, M.; Thoma, C.; Vay, J-L; Wadron, W.L.; Wurtele, J.S.; Welch, D.R.; Westenskow, G.A.; Yu, S.S.

2005-01-01

Key scientific results from recent experiments, modeling tools, and heavy ion accelerator research are summarized that explore ways to investigate the properties of high energy density matter in heavy-ion-driven targets, in particular, strongly-coupled plasmas at 0.01 to 0.1 times solid density for studies of warm dense matter, which is a frontier area in high energy density physics. Pursuit of these near-term objectives has resulted in many innovations that will ultimately benefit heavy ion inertial fusion energy. These include: neutralized ion beam compression and focusing, which hold the promise of greatly improving the stage between the accelerator and the target chamber in a fusion power plant; and the Pulse Line Ion Accelerator (PLIA), which may lead to compact, low-cost modular linac drivers

A High Power Density Integrated Charger for Electric Vehicles with Active Ripple Compensation

Directory of Open Access Journals (Sweden)

Liwen Pan

2015-01-01

Full Text Available This paper suggests a high power density on-board integrated charger with active ripple compensation circuit for electric vehicles. To obtain a high power density and high efficiency, silicon carbide devices are reported to meet the requirement of high-switching-frequency operation. An integrated bidirectional converter is proposed to function as AC/DC battery charger and to transfer energy between battery pack and motor drive of the traction system. In addition, the conventional H-bridge circuit suffers from ripple power pulsating at second-order line frequency, and a scheme of active ripple compensation circuit has been explored to solve this second-order ripple problem, in which a pair of power switches shared traction mode, a ripple energy storage capacitor, and an energy transfer inductor. Simulation results in MATLAB/Simulink validated the eligibility of the proposed topology. The integrated charger can work as a 70 kW motor drive circuit or a converter with an active ripple compensation circuit for 3 kW charging the battery. The impact of the proposed topology and control strategy on the integrated charger power losses, efficiency, power density, and thermal performance has also been analysed and simulated.

The ORNL fusion power demonstration study

International Nuclear Information System (INIS)

Shannon, T.E.; Steiner, D.

1978-01-01

In this paper, we review the design approach developed in the ORNL Fusion Power Demonstration Study [1]. The major emphasis of this study is in the application of current and near-term technology as the most logical path to near-term demonstration of tokamak fusion power. In addition we are pursuing a number of concepts to simplify the tokamak reactor to be more acceptable to the utility industry as a future source of energy. The discussion will focus on the areas having the greatest overall impact on reactor feasibility: 1) overall size and power output, 2) remote maintenance considerations, 3) electrical power supplies, 4) blanket design; and 5) economics. The tokamak device, by nature of its configuration and pulsed operation, is an exceptionally complex engineering design problem. We have concluded that innovative design concepts are essential to cope with this basic complexity. We feel that the feasibility of tokamak fusion power has been significantly improved by these design approaches. (author)

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.

Helical-type device and laser fusion. Rivals for tokamak-type device at n-fusion development in Japan

International Nuclear Information System (INIS)

Anon.

1994-01-01

Under the current policy on the research and development of nuclear fusion in Japan, as enunciated by the Atomic Energy Commission of Japan, the type of a prototype fusion reactor will be chosen after 2020 from tokamak, helical or some other type including the inertial confinement fusion using lasers. A prototype fusion reactor is the next step following the tokamak type International Thermonuclear Experimental Reactor (ITER). With the prototype reactor, the feasibility as a power plant will be examined. At present the main research and development of nuclear fusion in Japan are on tokamak type, which have been promoted by Japan Atomic Energy Research Institute (JAERI). As for the other types of nuclear fusion, researches have been carried out on the helical type in Kyoto University and National Institute for Fusion Science (NIFS), the mirror type in Tsukuba University, the tokamak type using superconductive coils in Kyushu University, and the laser fusion in Osaka University. The features and the present state of research and development of the Large Helical Device and the laser fusion which is one step away from the break-even condition are reported. (K.I.)

Fusion Power Deployment

International Nuclear Information System (INIS)

Schmidt, J.A.; Ogden, J.M.

2002-01-01

Fusion power plants could be part of a future portfolio of non-carbon dioxide producing energy supplies such as wind, solar, biomass, advanced fission power, and fossil energy with carbon dioxide sequestration. In this paper, we discuss key issues that could impact fusion energy deployment during the last half of this century. These include geographic issues such as resource availability, scale issues, energy storage requirements, and waste issues. The resource needs and waste production associated with fusion deployment in the U.S. should not pose serious problems. One important feature of fusion power is the fact that a fusion power plant should be locatable within most local or regional electrical distribution systems. For this reason, fusion power plants should not increase the burden of long distance power transmission to our distribution system. In contrast to fusion power, regional factors could play an important role in the deployment of renewable resources such as wind, solar and biomass or fossil energy with CO2 sequestration. We examine the role of these regional factors and their implications for fusion power deployment

Optimization of nonthermal fusion power consistent with channeling of charged fusion product energy

International Nuclear Information System (INIS)

Snyder, P.B.; Herrmann, M.C.; Fisch, N.J.

1994-01-01

If the energy of charged fusion products can be diverted directly to fuel ions, non-Maxwellian fuel ion distributions and temperature differences between species will result. To determine the importance of these nonthermal effects, the fusion power density is optimized at constant-β for non-thermal distributions that are self-consistently maintained by channeling of energy from charged fusion products. For D-T and D- 3 He reactors, with 75% of charged fusion product power diverted to fuel ions, temperature differences between electrons and ions increase the reactivity by 40-70%, while non-Maxwellian fuel ion distributions and temperature differences between ionic species increase the reactivity by an additional 3-15%

Towards assembly completion and preparation of experimental campaigns of Wendelstein 7-X in the perspective of a path to a stellarator fusion power plant

Energy Technology Data Exchange (ETDEWEB)

Klinger, T., E-mail: thomas.klinger@ipp.mpg.de; Baylard, C.; Beidler, C.D.; Boscary, J.; Bosch, H.S.; Dinklage, A.; Hartmann, D.; Helander, P.; Maßberg, H.; Peacock, A.; Pedersen, T.S.; Rummel, T.; Schauer, F.; Wegener, L.; Wolf, R.

2013-10-15

superconducting current leads, one pair for each coil type; and (c) assembly of the device periphery including diagnostics and heating systems. In the second part we report on the present status of planning for the first operation phase (5–10 s discharge duration at 8 MW heating power), the completion and hardening of the device for full power steady-state operation, and the second operation phase (up to 30 min discharge duration at 10 MW heating power). It is the ultimate goal of operation phase one to develop credible and robust discharge scenarios for the high-power steady-state operation phase two. Beyond the improved equilibrium, confinement, and stability properties owing to stellarator optimization, this requires density control, impurity control, edge iota control as well as high density microwave heating. Of paramount importance is the operation of the island divertor, which is realized in the first operation phase as an inertially cooled conventional graphite target divertor. It will be replaced later on by the steady-state capable island divertor with its water-cooled carbon fiber reinforced carbon target elements.

Controllers for high-performance nuclear fusion plasmas

NARCIS (Netherlands)

Baar, de M.R.

2012-01-01

A succesful nuclear fusion reactor will confine plasma at hig temperatures and densities, with low thermal losses. The workhorse of the nuclear fusion community is the tokamak, a toroidal device in which plasmas are confined by poloidal and toroidal magnetic fields. Ideally, the confirming magnetic

Fusion power economy of scale

International Nuclear Information System (INIS)

Dolan, T.J.

1993-01-01

In the next 50 yr, the world will need to develop hundreds of gigawatts of non-fossil-fuel energy sources for production of electricity and fuels. Nuclear fusion can probably provide much of the required energy economically, if large single-unit power plants are acceptable. Large power plants are more common than most people realize: There are already many multiple-unit power plants producing 2 to 5 GW(electric) at a single site. The cost of electricity (COE) from fusion energy is predicted to scale as COE ∼ COE 0 (P/P 0 ) -n , where P is the electrical power, the subscript zero denotes reference values, and the exponent n ∼ 0.36 to 0.7 in various designs. The validity ranges of these scalings are limited and need to be extended by future work. The fusion power economy of scale derives from four interrelated effects: improved operations and maintenance costs; scaling of equipment unit costs; a geometric effect that increases the mass power density; and reduction of the recirculating power fraction. Increased plasma size also relaxes the required confinement parameters: For the same neutron wall loading, larger tokamaks can use lower magnetic fields. Fossil-fuel power plants have a weaker economy of scale than fusion because the fuel costs constitute much of their COE. Solar and wind power plants consist of many small units, so they have little economy of scale. Fission power plants have a strong economy of scale but are unable to exploit it because the maximum unit size is limited by safety concerns. Large, steady-state fusion reactors generating 3 to 6 GW(electric) may be able to produce electricity for 4 to 5 cents/kW·h, which would be competitive with other future energy sources. 38 refs., 6 figs., 6 tabs

High to ultra-high power electrical energy storage.

Science.gov (United States)

Sherrill, Stefanie A; Banerjee, Parag; Rubloff, Gary W; Lee, Sang Bok

2011-12-14

High power electrical energy storage systems are becoming critical devices for advanced energy storage technology. This is true in part due to their high rate capabilities and moderate energy densities which allow them to capture power efficiently from evanescent, renewable energy sources. High power systems include both electrochemical capacitors and electrostatic capacitors. These devices have fast charging and discharging rates, supplying energy within seconds or less. Recent research has focused on increasing power and energy density of the devices using advanced materials and novel architectural design. An increase in understanding of structure-property relationships in nanomaterials and interfaces and the ability to control nanostructures precisely has led to an immense improvement in the performance characteristics of these devices. In this review, we discuss the recent advances for both electrochemical and electrostatic capacitors as high power electrical energy storage systems, and propose directions and challenges for the future. We asses the opportunities in nanostructure-based high power electrical energy storage devices and include electrochemical and electrostatic capacitors for their potential to open the door to a new regime of power energy.

Parameter study toward economical magnetic fusion power reactors

International Nuclear Information System (INIS)

Yoshida, Tomoaki; Okano, Kunihiko; Nanahara, Toshiya; Hatayama, Akiyoshi; Yamaji, Kenji; Takuma, Tadashi.

1996-01-01

Although the R and D of nuclear fusion reactors has made a steady progress as seen in ITER project, it has become of little doubt that fusion power reactors require hugeness and enormous amount of construction cost as well as surmounting the physics and engineering difficulties. Therefore, it is one of the essential issues to investigate the prospect of realizing fusion power reactors. In this report we investigated the effects of physics and engineering improvements on the economics of ITER-like steady state tokamak fusion reactors using our tokamak system and costing analysis code. With the results of this study, we considered what is the most significant factor for realizing economical competitive fusion reactors. The results show that with the conventional TF coil maximum field (12T), physics progress in β-value (or Troyon coefficient) has the most considerable effect on the reduction of fusion plant COE (Cost of Electricity) while the achievement of H factor = 2-3 and neutron wall load =∼5MW/m 2 is necessary. The results also show that with the improvement of TF coil maximum field, reactors with a high aspect ratio are economically advantageous because of low plasma current driving power while the improvement of current density in the conductors and yield strength of support structures is indispensable. (author)

Superconducting (radiation hardened) magnets for mirror fusion devices

International Nuclear Information System (INIS)

Henning, C.D.; Dalder, E.N.C.; Miller, J.R.; Perkins, J.R.

1983-01-01

Superconducting magnets for mirror fusion have evolved considerably since the Baseball II magnet in 1970. Recently, the Mirror Fusion Test Facility (MFTF-B) yin-yang has been tested to a full field of 7.7 T with radial dimensions representative of a full scale reactor. Now the emphasis has turned to the manufacture of very high field solenoids (choke coils) that are placed between the tandem mirror central cell and the yin-yang anchor-plug set. For MFTF-B the choke coil field reaches 12 T, while in future devices like the MFTF-Upgrade, Fusion Power Demonstration and Mirror Advanced Reactor Study (MARS) reactor the fields are doubled. Besides developing high fields, the magnets must be radiation hardened. Otherwise, thick neutron shields increase the magnet size to an unacceptable weight and cost. Neutron fluences in superconducting magnets must be increased by an order of magnitude or more. Insulators must withstand 10 10 to 10 11 rads, while magnet stability must be retained after the copper has been exposed to fluence above 10 19 neutrons/cm 2

New aspects of high energy density plasma

International Nuclear Information System (INIS)

Hotta, Eiki

2005-10-01

The papers presented at the symposium on 'New aspects of high energy density plasma' held at National Institute for Fusion Science are collected in this proceedings. The papers reflect the present status and recent progress in the experiments and theoretical works on high energy density plasma produced by pulsed power technology. The 13 of the presented papers are indexed individually. (J.P.N.)

Protective coatings for in-vessel fusion devices

International Nuclear Information System (INIS)

Brossa, F.

1984-01-01

Coatings of Al/Si, SAP (Sintered Aluminium Powder), Al 2 O 3 , TiC (low-Z material) and Ta have been developed for in-vessel component protection. Anodic oxidation, vapor depositions, reactive sputtering, chemical vapor deposition (CVD) and plasma spray have been the coating formation methods studied. AISI 316, 310, 304, Inconel 600 and Mo were adopted as base materials. the coatings were characterized in terms of composition, structure and connection with the supporting material. The behavior of coatings under H + , D + and He + irradiation in the energy range 100 eV-8 keV was tested and compared to the solid massive samples. TiC and Ta coatings were tested with thermal shock under power density pulses of 1 kW/cm 2 generated by an electron beam gun. Temperature-dependence of the erosion of TiC by vacuum arcs in a magnetic field was also studied. TiC coatings have low sputtering values, good resistance to arcing and a high chemical stability. TiC and Ta, CVD and plasma spray coatings are thermal-shock resistant. High thermal loads produce cracks but no spalling. Destruction occurred only after melting of the base material. The plasma spray coating method seems to be most appropriate for developing remote handling applications in fusion devices. (orig.)

High-density fusion and the Z-pinch

International Nuclear Information System (INIS)

Hartman, C.W.; Eddleman, J.L.; Munger, R.H.

1975-01-01

The formation of a Z-pinch in dense gas is investigated using numerical modeling in one and two dimensions. Hot, dense Z-pinches are calculated with n approximately 2 x 10 21 cm 3 and T = 10 keV. Relaxation by sausage instability of an unstable pinch profile to a marginally stable one is calculated along with end losses in 2 dimensions to show that, if plasma is confined for N = 50 to 200 sound transits across the radius a, pinches with length L = Na are of interest for fusion power. A conceptual, ''no-wall'' fusion reactor is discussed. (author)

Ultrathin Coaxial Fiber Supercapacitors Achieving High Energy and Power Densities.

Science.gov (United States)

Shen, Caiwei; Xie, Yingxi; Sanghadasa, Mohan; Tang, Yong; Lu, Longsheng; Lin, Liwei

2017-11-15

Fiber-based supercapacitors have attracted significant interests because of their potential applications in wearable electronics. Although much progress has been made in recent years, the energy and power densities, mechanical strength, and flexibility of such devices are still in need of improvement for practical applications. Here, we demonstrate an ultrathin microcoaxial fiber supercapacitor (μCFSC) with high energy and power densities (2.7 mW h/cm 3 and 13 W/cm 3 ), as well as excellent mechanical properties. The prototype with the smallest reported overall diameter (∼13 μm) is fabricated by successive coating of functional layers onto a single micro-carbon-fiber via a scalable process. Combining the simulation results via the electrochemical model, we attribute the high performance to the well-controlled thin coatings that make full use of the electrode materials and minimize the ion transport path between electrodes. Moreover, the μCFSC features high bending flexibility and large tensile strength (more than 1 GPa), which make it promising as a building block for various flexible energy storage applications.

Laser fusion and high energy density science

International Nuclear Information System (INIS)

Kodama, Ryosuke

2005-01-01

High-power laser technology is now opening a variety of new fields of science and technology using laser-produced plasmas. The laser plasma is now recognized as one of the important tools for the investigation and application of matter under extreme conditions, which is called high energy density science. This chapter shows a variety of applications of laser-produced plasmas as high energy density science. One of the more attractive industrial and science applications is the generation of intense pulse-radiation sources, such as the generation of electro-magnetic waves in the ranges of EUV (Extreme Ultra Violet) to gamma rays and laser acceleration of charged particles. The laser plasma is used as an energy converter in this regime. The fundamental science applications of high energy density physics are shown by introducing laboratory astrophysics, the equation of state of high pressure matter, including warm dense matter and nuclear science. Other applications are also presented, such as femto-second laser propulsion and light guiding. Finally, a new systematization is proposed to explore the possibility of the high energy density plasma application, which is called high energy plasma photonics''. This is also exploration of the boundary regions between laser technology and beam optics based on plasma physics. (author)

Oscillatory vapour shielding of liquid metal walls in nuclear fusion devices

NARCIS (Netherlands)

van Eden, G.G.; Kvon, V.; Van De Sanden, M.C.M.; Morgan, T.W.

2017-01-01

Providing an efficacious plasma facing surface between the extreme plasma heat exhaust and the structural materials of nuclear fusion devices is a major challenge on the road to electricity production by fusion power plants. The performance of solid plasma facing surfaces may become critically

Panel discussion on prospects for fusion power

International Nuclear Information System (INIS)

Sheffield, J.

1986-01-01

Although substantial progress is made every year in fusion research, the projected time to realize the ultimate goal of commercial fusion always seems to be 25 to 30 years away. This shifting schedule reflects the underlying difficulty of developing fusion. Every new technology improves the prospects for success, yet as each fusion mountain is scaled, it serves mainly to bring a better view of the next mountain. Two questions are considered: (1) why are so many configurations studied, and (2) what constitutes an economic power density

Evaluation of divertor conceptual designs for a fusion power plant

International Nuclear Information System (INIS)

Ferrari, M.; Giancarli, L.; Kleefeldt, K.; Nardi, C.; Roedig, M.; Reimann, J.; Salavy, J.F.

2001-01-01

In the frame of the preliminary study of plants suitable for the energy production from the fusion power, particular emphasis has been given on the divertor studies. Since a significant percentage of the power generated from the fusion process is absorbed in the divertor, the thermal efficiency of the power conversion cycle requires a high coolant outlet temperature of the divertor, leading to solutions that are different from those adopted for the present experimental fusion plants. Therefore, copper alloys having extremely high thermal conductivity, cannot be used as structural material for this kind of devices. The most suitable coolants to be used in the divertor are water, helium and liquid metals. A conceptual design study has been developed for each of these three fluids, with the aim to evaluate the maximum allowable thermal flux at the divertor target plate and the R and D requirements for each solution. While a water-cooled divertor can be designed with a limited R and D effort, the development of helium or liquid metal cooled divertors requires a more engaging R and D program

Neutral particle kinetics in fusion devices

International Nuclear Information System (INIS)

Tendler, M.; Heifetz, D.

1986-05-01

The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub α/ emission rates, plenum pressures, and charge-exchange emission spectra

Neutral particle kinetics in fusion devices

Energy Technology Data Exchange (ETDEWEB)

Tendler, M.; Heifetz, D.

1986-05-01

The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub ..cap alpha../ emission rates, plenum pressures, and charge-exchange emission spectra.

Technology breakthroughs in high performance metal-oxide-semiconductor devices for ultra-high density, low power non-volatile memory applications

Science.gov (United States)

Hong, Augustin Jinwoo

Non-volatile memory devices have attracted much attention because data can be retained without power consumption more than a decade. Therefore, non-volatile memory devices are essential to mobile electronic applications. Among state of the art non-volatile memory devices, NAND flash memory has earned the highest attention because of its ultra-high scalability and therefore its ultra-high storage capacity. However, human desire as well as market competition requires not only larger storage capacity but also lower power consumption for longer battery life time. One way to meet this human desire and extend the benefits of NAND flash memory is finding out new materials for storage layer inside the flash memory, which is called floating gate in the state of the art flash memory device. In this dissertation, we study new materials for the floating gate that can lower down the power consumption and increase the storage capacity at the same time. To this end, we employ various materials such as metal nanodot, metal thin film and graphene incorporating complementary-metal-oxide-semiconductor (CMOS) compatible processes. Experimental results show excellent memory effects at relatively low operating voltages. Detailed physics and analysis on experimental results are discussed. These new materials for data storage can be promising candidates for future non-volatile memory application beyond the state of the art flash technologies.

Conceptual designs of two petawatt-class pulsed-power accelerators for high-energy-density-physics experiments

Directory of Open Access Journals (Sweden)

W. A. Stygar

2015-11-01

(MHD simulations suggest Z 300 will deliver 4.3 MJ to the liner, and achieve a yield on the order of 18 MJ. Z 800 is 52 m in diameter and stores 130 MJ. This accelerator generates 890 TW at the output of its LTD system, and delivers 65 MA in 113 ns to a MagLIF target. The peak electrical power at the MagLIF liner is 2500 TW. The principal goal of Z 800 is to achieve high-yield thermonuclear fusion; i.e., a yield that exceeds the energy initially stored by the accelerator’s capacitors. 2D MHD simulations suggest Z 800 will deliver 8.0 MJ to the liner, and achieve a yield on the order of 440 MJ. Z 300 and Z 800, or variations of these accelerators, will allow the international high-energy-density-physics community to conduct advanced inertial-confinement-fusion, radiation-physics, material-physics, and laboratory-astrophysics experiments over heretofore-inaccessible parameter regimes.

Fusion power

International Nuclear Information System (INIS)

Hancox, R.

1981-01-01

The principles of fusion power, and its advantages and disadvantages, are outlined. Present research programmes and future plans directed towards the development of a fusion power reactor, are summarized. (U.K.)

Suggestions for an updated fusion power program

International Nuclear Information System (INIS)

Clarke, J.F.

1976-02-01

This document contains suggestions for a revised CTR Program strategy which should allow us to achieve equivalent goals while operating within the above constraints. The revised program is designed around three major facilities. The first is an upgrading of the present TFTR facility which will provide a demonstration of the generation of tens of megawatts electric equivalent originally envisioned for the 1985 EPR. The second device is the TTAP which will allow the integration and optimization of the plasma physics results obtained from the next generation of plasma physics experiments. The improvement in tokamak reactor operation resulting from this optimization of fusion plasma performance will enable an EPR to be designed which will produce several hundred megawatts of electric power by 1990. This will move the fusion program much closer to its goal of commercial fusion power by the turn of the century. In addition to this function the TTAP will serve as a prototype of the 1990 EPR system, thus making more certain the successful operation of this device. The third element of this revised program is an intense radiation damage facility which will provide the radiation damage information necessary for the EPR and subsequent fusion reactor facilities. The sum total of experience gained from reacting plasma experiments on TFTR, reactor grade plasma optimization and technological prototyping on TTAP, and end of life radiation damage results from the intense neutron facility will solve all of the presently foreseen problems associated with a tokamak fusion power reactor except those associated with the external nuclear systems. These external system problems such as tritium breeding and optimal power recovery can be developed in parallel on the 1990 EPR

Overview of the Fusion Engineering Device (FED) design

International Nuclear Information System (INIS)

Steiner, D.; Flanagan, C.A.

1981-01-01

The device has a major radius of 5.0 m with a plasma minor radius of 1.3 m elongated by 1.6. Capability is provided for operating the toroidal field coils up to 10 T, but the bulk of the operations are designed for 8 T. At 8-T conditions the fusion power is approx. 180 MW (neutron wall loading approx. 0.4 MW/m 2 ) and a plasma Q of approx. 5 is expected. At 10-T conditions, which are expected to be limited to about 10% of the total operations, the fusion power is approx. 450 MW (approx. 1.0 MW/m 2 ) and ignition is expected

Overview of the fusion engineering device (FED) design

International Nuclear Information System (INIS)

Steiner, D.; Flanagan, C.A.

1981-10-01

The device has a major radius of 5.0 m with a plasma minor radius of 1.3 m elongated by 1.6. Capability is provided for operating the toroidal field coils up to 10 T, but the bulk of the operations are designed for 8 T. At 8-T conditions, the fusion power is approx. 180 MW (neutron wall loading approx. 0.4 MW/m 2 ) and a plasma Q of approx. 5 is expected. At 10-T conditions, which are expected to be limited to about 10% of the total operations, the fusion power is approx. 450 MW (approx. 1.0 MW/m 2 ) and ignition is expected

High temperature superconductors for fusion magnets -influence of neutron irradiation

International Nuclear Information System (INIS)

Chudy, M.; Eisterer, M.; Weber, H. W.

2010-01-01

In this work authors present the results of study of influence of neutron irradiation of high temperature superconductors for fusion magnets. High temperature superconductors (type of YBCO (Yttrium-Barium-Copper-Oxygen)) are strong candidates to be applied in the next step of fusion devices. Defects induced by fast neutrons are effective pinning centres, which can significantly improve critical current densities and reduce J c anisotropy. Due to induced lattice disorder, T c is reduced. Requirements for ITER (DEMO) are partially achieved at 64 K.

Impurity studies in fusion devices using laser-fluorescence-spectroscopy

International Nuclear Information System (INIS)

Husinsky, W.R.

1980-08-01

Resonance fluorescence excitation of neutral atoms using tunable radiation from dye lasers offers a number of unique advantages for impurity studies in fusion devices. Using this technique, it is possible to perform local, time-resolved measurements of the densities and velocity distributions of metallic impurities in fusion devices without disturbing the plasma. Velocities are measured by monitoring the fluorescence intensity while tuning narrow bandwidth laser radiation through the Doppler - broadened absorbtion spectrum of the transition. The knowledge of the velocity distribution of neutral impurities is particularly useful for the determination of impurity introduction mechanisms. The laser fluorescence technique will be described in terms of its application to metallic impurities in fusion devices and related laboratory experiments. Particular attention will be given to recent results from the ISX-B tokamak using pulsed dye lasers where detection sensitivities for neutral Fe of 10 6 atoms/cm 3 with a velocity resolution of 600 m/sec (0.1 eV) have been achieved. Techniques for exciting plasma particles (H,D) will also be discussed

High power density yeast catalyzed microbial fuel cells

Science.gov (United States)

Ganguli, Rahul

Microbial fuel cells leverage whole cell biocatalysis to convert the energy stored in energy-rich renewable biomolecules such as sugar, directly to electrical energy at high efficiencies. Advantages of the process include ambient temperature operation, operation in natural streams such as wastewater without the need to clean electrodes, minimal balance-of-plant requirements compared to conventional fuel cells, and environmentally friendly operation. These make the technology very attractive as portable power sources and waste-to-energy converters. The principal problem facing the technology is the low power densities compared to other conventional portable power sources such as batteries and traditional fuel cells. In this work we examined the yeast catalyzed microbial fuel cell and developed methods to increase the power density from such fuel cells. A combination of cyclic voltammetry and optical absorption measurements were used to establish significant adsorption of electron mediators by the microbes. Mediator adsorption was demonstrated to be an important limitation in achieving high power densities in yeast-catalyzed microbial fuel cells. Specifically, the power densities are low for the length of time mediator adsorption continues to occur. Once the mediator adsorption stops, the power densities increase. Rotating disk chronoamperometry was used to extract reaction rate information, and a simple kinetic expression was developed for the current observed in the anodic half-cell. Since the rate expression showed that the current was directly related to microbe concentration close to the electrode, methods to increase cell mass attached to the anode was investigated. Electrically biased electrodes were demonstrated to develop biofilm-like layers of the Baker's yeast with a high concentration of cells directly connected to the electrode. The increased cell mass did increase the power density 2 times compared to a non biofilm fuel cell, but the power density

Pulsed power accelerators for particle beam fusion

International Nuclear Information System (INIS)

Martin, T.H.; Barr, G.W.; VanDevender, J.P.; White, R.A.; Johnson, D.L.

1980-01-01

Sandia National Laboratories is completing the construction phase of the Particle Beam Fusion Accelerator-I (PBFA-I). Testing of the 36 module, 30 TW, 1 MJ output accelerator is in the initial stages. The 4 MJ, PBFA Marx generator has provided 3.6 MA into water-copper sulfate load resistors with a spread from first to last Marx firing between 15 to 25 ns and an output power of 5.7 TW. This accelerator is a modular, lower voltage, pulsed power device that is capable of scaling to power levels exceeding 100 TW. The elements of the PBFA technology and their integration into an accelerator system for particle beam fusion will be discussed

STAR Power, an Interactive Educational Fusion CD with a Dynamic, Shaped Tokamak Power Plant Simulator

Science.gov (United States)

Leuer, J. A.; Lee, R. L.; Kellman, A. G.; Chapman Nutt, G. C., Jr.; Holley, G.; Larsen, T. A.

2000-10-01

We describe an interactive, educational fusion adventure game developed within our fusion education program. The theme of the adventure is start-up of a state-of-the-art fusion power plant. To gain access to the power plant control room, the student must complete several education modules, including topics on building an atom, fusion reactions, charged particle motion in electric and magnetic fields, and building a power plant. Review questions, a fusion video, library material and glossary provide additional resources. In the control room the student must start-up a complex, dynamic fusion power plant. The simulation model contains primary elements of a tokamak based device, including a magnetic shaper capable of producing limited and diverted elongated plasmas. A zero dimensional plasma model based on ITER scaling and containing rate based conservation equations provides dynamic feedback through major control parameters such as toroidal field, fueling rate and heating. The game is available for use on PC and Mac. computers. Copies will be available at the conference.

Compact approach to fusion power reactors

International Nuclear Information System (INIS)

Hagenson, R.L.; Krakowski, R.A.; Bathke, C.G.; Miller, R.L.

1984-01-01

The potential of the Reversed-Field Pinch (RFP) for development into an efficient, compact, copper-coil fusion reactor has been quantified by comprehensive parametric tradeoff studies. These compact systems promise to be competitive in size, power density, and cost to alternative energy sources. Conceptual engineering designs that largely substantiate these promising results have since been completed. This 1000-MWe(net) design is described along with a detailed rationale and physics/technology assessment for the compact approach to fusion

Sub-micrometer-thick all-solid-state supercapacitors with high power and energy densities

Energy Technology Data Exchange (ETDEWEB)

Meng, Fanhui [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, and School of Chemistry and Chemical Engineering, Shandong University, Jinan 250061 (China); Ding, Yi [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, and School of Chemistry and Chemical Engineering, Shandong University, Jinan 250061 (China); Shandong Applied Research Center for Gold Technology (Au-SDARC), Yantai 264005 (China)

2011-09-15

A sub-micrometer-thick, flexible, all-solid-state supercapacitor is fabricated. Through simultaneous realization of high dispersity of pseudocapacitance materials and quick electrode response, the hybrid nanostructures show enhanced volumetric capacitance and excellent stability, as well as very high power and energy densities. This suggests their potential as next-generation, high-performance energy conversion and storage devices for wearable electronics. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

ARC: A compact, high-field, fusion nuclear science facility and demonstration power plant with demountable magnets

Energy Technology Data Exchange (ETDEWEB)

Sorbom, B.N., E-mail: bsorbom@mit.edu; Ball, J.; Palmer, T.R.; Mangiarotti, F.J.; Sierchio, J.M.; Bonoli, P.; Kasten, C.; Sutherland, D.A.; Barnard, H.S.; Haakonsen, C.B.; Goh, J.; Sung, C.; Whyte, D.G.

2015-11-15

Highlights: • ARC reactor designed to have 500 MW fusion power at 3.3 m major radius. • Compact, simplified design allowed by high magnetic fields and jointed magnets. • ARC has innovative plasma physics solutions such as inboardside RF launch. • High temperature superconductors allow high magnetic fields and jointed magnets. • Liquid immersion blanket and jointed magnets greatly simplify tokamak reactor design. - Abstract: The affordable, robust, compact (ARC) reactor is the product of a conceptual design study aimed at reducing the size, cost, and complexity of a combined fusion nuclear science facility (FNSF) and demonstration fusion Pilot power plant. ARC is a ∼200–250 MWe tokamak reactor with a major radius of 3.3 m, a minor radius of 1.1 m, and an on-axis magnetic field of 9.2 T. ARC has rare earth barium copper oxide (REBCO) superconducting toroidal field coils, which have joints to enable disassembly. This allows the vacuum vessel to be replaced quickly, mitigating first wall survivability concerns, and permits a single device to test many vacuum vessel designs and divertor materials. The design point has a plasma fusion gain of Q{sub p} ≈ 13.6, yet is fully non-inductive, with a modest bootstrap fraction of only ∼63%. Thus ARC offers a high power gain with relatively large external control of the current profile. This highly attractive combination is enabled by the ∼23 T peak field on coil achievable with newly available REBCO superconductor technology. External current drive is provided by two innovative inboard RF launchers using 25 MW of lower hybrid and 13.6 MW of ion cyclotron fast wave power. The resulting efficient current drive provides a robust, steady state core plasma far from disruptive limits. ARC uses an all-liquid blanket, consisting of low pressure, slowly flowing fluorine lithium beryllium (FLiBe) molten salt. The liquid blanket is low-risk technology and provides effective neutron moderation and shielding, excellent

An Electrochemical Capacitor with Applicable Energy Density of 7.4 Wh/kg at Average Power Density of 3000 W/kg.

Science.gov (United States)

Zhai, Teng; Lu, Xihong; Wang, Hanyu; Wang, Gongming; Mathis, Tyler; Liu, Tianyu; Li, Cheng; Tong, Yexiang; Li, Yat

2015-05-13

Electrochemical capacitors represent a new class of charge storage devices that can simultaneously achieve high energy density and high power density. Previous reports have been primarily focused on the development of high performance capacitor electrodes. Although these electrodes have achieved excellent specific capacitance based on per unit mass of active materials, the gravimetric energy densities calculated based on the weight of entire capacitor device were fairly small. This is mainly due to the large mass ratio between current collector and active material. We aimed to address this issue by a 2-fold approach of minimizing the mass of current collector and increasing the electrode performance. Here we report an electrochemical capacitor using 3D graphene hollow structure as current collector, vanadium sulfide and manganese oxide as anode and cathode materials, respectively. 3D graphene hollow structure provides a lightweight and highly conductive scaffold for deposition of pseudocapacitive materials. The device achieves an excellent active material ratio of 24%. Significantly, it delivers a remarkable energy density of 7.4 Wh/kg (based on the weight of entire device) at the average power density of 3000 W/kg. This is the highest gravimetric energy density reported for asymmetric electrochemical capacitors at such a high power density.

Development of MW gyrotrons for fusion devices by University of Tsukuba

International Nuclear Information System (INIS)

Minami, R.; Kariya, T.; Imai, T.; Numakura, T.; Endo, Y.; Nakabayashi, H.; Eguchi, T.; Shimozuma, T.; Kubo, S.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Mutoh, T.; Ito, S.; Idei, H.; Zushi, H.; Yamaguchi, Y.; Sakamoto, Keishi; Mitsunaka, Y.

2012-11-01

Over-1 MW power gyrotrons for electron cyclotron heating (ECH) have been developed in the joint program of NIFS and University of Tsukuba. The obtained maximum outputs are 1.9 MW for 0.1 s on the 77 GHz Large Helical Device (LHD) tube and 1.0 MW for 1 ms on the 28 GHz GAMMA 10 one, which are new records in these frequency ranges. In long pulse operation, 300 kW for 40 min at 77 GHz and 540 kW for 2 s at 28 GHz were achieved. A new program of 154 GHz 1 MW development has started for high density plasma heating in LHD and the first tube has been fabricated. These lower frequency tubes like 77 GHz or 28 GHz one are also important for advanced magnetic fusion devices, which use Electron Bernstein Wave (EBW) heating / current drive. As a next activity of 28 GHz gyrotron, we have already started the development of over-1.5 MW gyrotron and a new design study of 28 GHz / 35 GHz dual frequency gyrotron, which indicates the practicability of the multi-purpose gyrotron. (author)

The role of fusion as a future power source

International Nuclear Information System (INIS)

Kintner, E.E.; Hirsch, R.L.

1977-01-01

Nations of western Europe, Japan, the Soviet Union, and the United States are working together to demonstrate the practicality of fusion power early in the 21st century. Many difficult engineering problems make fusion development one of the most formidable scientific and technological challenges ever attempted. However, the outlook is promising for achieving an inexhaustible energy source that is safe, economic, and with acceptable environmental effects. The United States magnetic fusion power development program aims at producing fusion energy experimentally in the early 1980's and demonstrating power production on a commercial scale before 2000. This prognosis reflects the confidence gained in scientific successes of the late 1960's through the present. However, many physics problems remain to be solved and many complex engineering problems without obvious solutions await attention. In response to experimental successes and the perceived importance of the fusion energy alternative, the United States effort has grown rapidly. Scientific investigations of plasma physics continue while planned engineering studies lead toward the practical goal of a commercial technology that will take a prominent place among available energy sources of the next century. Development of laser and electron beam fusion proceeds. Alternative fusion devices are investigated for their potential feasibility while the tokamak configuration is used for principal experimental devices. A national program plan and budget coordinates the efforts of federal laboratories, universities and industry. The utilities industry conducts an independent program which is increasingly coordinated with government-sponsored activity. Fusion energy programs of several nations benefit one another and should cooperate more closely in specific problem areas. Achievement of practical fusion power could be advanced through more effective mutually supporting fusion development programs. The economic and technical

Overview of the TITAN-II reversed-field pinch aqueous fusion power core design

Energy Technology Data Exchange (ETDEWEB)

Wong, C.P.C.; Creedon, R.L.; Grotz, S.; Cheng, E.T.; Sharafat, S.; Cooke, P.I.H.

1988-03-01

TITAN-II is a compact, high power density Reversed-Field Pinch fusion power reactor design based on the aqueous lithium solution fusion power core concept. The selected breeding and structural materials are LiNO/sub 3/ and 9-C low activation ferritic steel, respectively. TITAN-II is a viable alternative to the TITAN-I lithium self-cooled design for the Reversed-Field Pinch reactor to operate at a neutron wall loading of 18 MWm/sup 2/. Submerging the complete fusion power core and the primary loop in a large pool of cool water will minimize the probability of radioactivity release. Since the protection of the large pool integrity is the only requirement for the protection of the public, TITAN-II is a passive safety assurance design. 13 refs., 3 figs., 1 tab.

Overview of the TITAN-II reversed-field pinch aqueous fusion power core design

Energy Technology Data Exchange (ETDEWEB)

Wong, C.P.C.; Creedon, R.L.; Cheng, E.T. (General Atomic Co., San Diego, CA (USA)); Grotz, S.P.; Sharafat, S.; Cooke, P.I.H. (California Univ., Los Angeles (USA). Dept. of Mechanical, Aerospace and Nuclear Engineering; California Univ., Los Angeles, CA (USA). Inst. for Plasma and Fusion Research); TITAN Research Group

1989-04-01

TITAN-II is a compact, high-power-density Reversed-Field Pinch fusion power reactor design based on the aqueous lithium solution fusion power core concept. The selected breeding and structural materials are LiNO/sub 3/ and 9-C low activation ferritic steel, respectively. TITAN-II is a viable alternative to the TITAN-I lithium self-cooled design for the Reversed-Field Pinch reactor to operate at a neutron wall loading of 18 MW/m/sup 2/. Submerging the complete fusion power core and the primary loop in a large pool of cool water will minimize the probability of radioactivity release. Since the protection of the large pool integrity is the only requirement for the protection of the public, TITAN-II is a level 2 of passive safety assurance design. (orig.).

Optimization of nonthermal fusion power consistent with energy channeling

International Nuclear Information System (INIS)

Snyder, P.B.; Herrmann, M.C.; Fisch, N.J.

1995-02-01

If the energy of charged fusion products can be diverted directly to fuel ions, non-Maxwellian fuel ion distributions and temperature differences between species will result. To determine the importance of these nonthermal effects, the fusion power density is optimized at constant-β for nonthermal distributions that are self-consistently maintained by channeling of energy from charged fusion products. For D-T and D- 3 He reactors, with 75% of charged fusion product power diverted to fuel ions, temperature differences between electrons and ions increase the reactivity by 40-70%, while non- Maxwellian fuel ion distributions and temperature differences between ionic species increase the reactivity by an additional 3-15%

Study of lower hybrid current drive system in tokamak fusion devices

International Nuclear Information System (INIS)

Maebara, Sunao

2001-01-01

This report describes R and D of a high-power klystron, RF vacuum window, low-outgassing antenna and a front module for a plasma-facing antenna aiming the 5 GHz Lower Hybrid Current Drive (LHCD) system for the next Tokamak Fusion Device. 5 GHz klystron with a low-perveances of 0.7 μP is designed for a high-power and a high-efficiency, the output-power of 715 kW and the efficiency of 63%, which are beyond the conventional design scaling of 450 kW-45%, are performed using the prototype klystron which operates at the pulse duration of 15 μsec. A new pillbox window, which has an oversized length in both the axial and the radial direction, are designed to reduce the RF power density and the electric field strength at the ceramics. It is evaluated that the power capability by cooling edge of ceramics is 1 MW with continuous-wave operation. The antenna module using Dispersion Strengthened Copper which combines high mechanical property up to 500degC with high thermal conductivity, are developed for a low-outgassing antenna in a steady state operation. It is found that the outgassing rate is in the lower range of 4x10 -6 Pam 3 /sm 2 at the module temperature of 300degC, which requires no active vacuum pumping of the LHCD antenna. A front module using Carbon Fiber Composite (CFC) are fabricated and tested for a plasma facing antenna which has a high heat-resistive. Stationary operation of the CFC module with water cooling is performed at the RF power of 46 MWm -2 (about 2 times higher than the design value) during 1000 sec, it is found that the outgassing rate is less than 10 -5 Pam 3 /sm 2 which is low enough for an antenna material. (author)

Dust in fusion devices-a multi-faceted problem connecting high- and low-temperature plasma physics

International Nuclear Information System (INIS)

Winter, J

2004-01-01

Small particles with sizes between a few nanometers and a few 10 μm (dust) are formed in fusion devices by plasma-surface interaction processes. Though it is not a major problem today, dust is considered a problem that could arise in future long pulse fusion devices. This is primarily due to its radioactivity and due to its very high chemical reactivity. Dust formation is particularly pronounced when carbonaceous wall materials are used. Dust particles can be transported in the tokamak over significant distances. Radioactivity leads to electrical charging of dust and to its interaction with plasmas and electric fields. This may cause interference with the discharge but may also result in options for particle removal. This paper discusses some of the multi-faceted problems using information both from fusion research and from low-temperature dusty plasma work

Power matching for pellet fusion

International Nuclear Information System (INIS)

Martin, R.L.; Arnold, R.C.

1976-01-01

The number of beams required for optimum power transfer from a given power source to the surface of a pellet is derived. The result is valid for linear optical systems, hence, for pellet fusion by laser or high energy ion beams. The optimum number of beams turns out to be inconceivably large for any practical system. Practical pellet fusion by lasers or high energy heavy ion beams must thus compromise physical principles in favor of reduced cost and optical complexity

Towards upper power levels: thermonuclear fusion

International Nuclear Information System (INIS)

Vedel, Jean

1983-01-01

This paper is a brief introduction to the use of power lasers to achieve controlled thermonuclear fusion. After shortly describing thermonuclear fusion and the conditions of temperature, density and duration required it is showed how the laser enables such conditions to be created. The neodymium-doped glass laser NOVA that is being installed at the Livermore laboratory in the USA is described; at the time of its completion in 1984, this laser will be the most powerful in the world. In comparison, the OCTAL laser in operation at the Limeil establishment ''Centre d'Etudes'' of ''Commissariat Francais a l'Energie Atomique'' (the French atomic energy authority) is more modest; it is presented here [fr

High-power microwave transmission and launching systems for fusion plasma heating systems

International Nuclear Information System (INIS)

Bigelow, T.S.

1989-01-01

Microwave power in the 30- to 300-GHz frequency range is becoming widely used for heating of plasma in present-day fusion energy magnetic confinement experiments. Microwave power is effective in ionizing plasma and heating electrons through the electron cyclotron heating (ECH) process. Since the power is absorbed in regions of the magnetic field where resonance occurs and launching antennas with narrow beam widths are possible, power deposition location can be highly controlled. This is important for maximizing the power utilization efficiency and improving plasma parameters. Development of the gyrotron oscillator tube has advanced in recent years so that a 1-MW continuous-wave, 140-GHz power source will soon be available. Gyrotron output power is typically in a circular waveguide propagating a circular electric mode (such as TE 0,2 ) or a whispering-gallery mode (such as TE 15,2 ), depending on frequency and power level. An alternative high-power microwave source currently under development is the free-electron laser (FEL), which may be capable of generating 2-10 MW of average power at frequencies of up to 500 GHz. The FEL has a rectangular output waveguide carrying the TE 0,1 mode. Because of its higher complexity and cost, the high-average-power FEL is not yet as extensively developed as the gyrotron. In this paper, several types of operating ECH transmission systems are discussed, as well systems currently being developed. The trend in this area is toward higher power and frequency due to the improvements in plasma density and temperature possible. Every system requires a variety of components, such as mode converters, waveguide bends, launchers, and directional couplers. Some of these components are discussed here, along with ongoing work to improve their performance. 8 refs

Fast power cycle for fusion reactors

International Nuclear Information System (INIS)

Powell, J.; Fillo, J.; Makowitz, H.

1978-01-01

The unique, deep penetration capability of 14 MeV neutrons produced in DT fusion reactions allows the generation of very high temperature working fluid temperatures in a thermal power cycle. In the FAST (Fusion Augmented Steam Turbine) power cycle steam is directly superheated by the high temperature ceramic refractory interior of the blanket, after being generated by heat extracted from the relatively cool blanket structure. The steam is then passed to a high temperature gas turbine for power generation. Cycle studies have been carried out for a range of turbine inlet temperatures [1600 0 F to 3000 0 F (870 to 1650 0 C)], number of reheats, turbine mechanical efficiency, recuperator effectiveness, and system pressure losses. Gross cycle efficiency is projected to be in the range of 55 to 60%, (fusion energy to electric power), depending on parameters selected. Turbine inlet temperatures above 2000 0 F, while they do increase efficiency somewhat, are not necessarily for high cycle efficiency

Applications of Skyrme energy-density functional to fusion reactions spanning the fusion barriers

International Nuclear Information System (INIS)

Liu Min; Wang, Ning; Li Zhuxia; Wu Xizhen; Zhao Enguang

2006-01-01

The Skyrme energy density functional has been applied to the study of heavy-ion fusion reactions. The barriers for fusion reactions are calculated by the Skyrme energy density functional with proton and neutron density distributions determined by using restricted density variational (RDV) method within the same energy density functional together with semi-classical approach known as the extended semi-classical Thomas-Fermi method. Based on the fusion barrier obtained, we propose a parametrization of the empirical barrier distribution to take into account the multi-dimensional character of real barrier and then apply it to calculate the fusion excitation functions in terms of barrier penetration concept. A large number of measured fusion excitation functions spanning the fusion barriers can be reproduced well. The competition between suppression and enhancement effects on sub-barrier fusion caused by neutron-shell-closure and excess neutron effects is studied

Alternate applications of fusion power: development of a high-temperature blanket for synthetic-fuel production

International Nuclear Information System (INIS)

Howard, P.A.; Mattas, R.F.; Krajcinovic, D.; DePaz, J.; Gohar, Y.

1981-11-01

This study has shown that utilization of the unique features of a fusion reactor can result in a novel and potentially economical method of decomposing steam into hydrogen and oxygen. Most of the power of fusion reactors is in the form of energetic neutrons. If this power could be used to produce high temperature uncontaminated steam, a large fraction of the energy needed to decomposee the steam could be supplied as thermal energy by the fusion reaction. Proposed high temperature electrolysis processes require steam temperature in excess of 1000 0 C for high efficiency. The design put forth in this study details a system that can accomplish that end

High Energy Density Sciences with High Power Lasers at SACLA

Science.gov (United States)

Kodama, Ryosuke

2013-10-01

One of the interesting topics on high energy density sciences with high power lasers is creation of extremely high pressures in material. The pressures of more than 0.1 TPa are the energy density corresponding to the chemical bonding energy, resulting in expectation of dramatic changes in the chemical reactions. At pressures of more than TPa, most of material would be melted on the shock Hugoniot curve. However, if the temperature is less than 1eV or lower than a melting point at pressures of more than TPa, novel solid states of matter must be created through a pressured phase transition. One of the interesting materials must be carbon. At pressures of more than TPa, the diamond structure changes to BC and cubic at more than 3TPa. To create such novel states of matter, several kinds of isentropic-like compression techniques are being developed with high power lasers. To explore the ``Tera-Pascal Science,'' now we have a new tool which is an x-ray free electron laser as well as high power lasers. The XFEL will clear the details of the HED states and also efficiently create hot dense matter. We have started a new project on high energy density sciences using an XFEL (SACLA) in Japan, which is a HERMES (High Energy density Revolution of Matter in Extreme States) project.

Advanced fusion in ICRF injected plasmas

International Nuclear Information System (INIS)

Carpignano, F.; Coppi, B.; Detragiache, P.; Migliuolo, S.; Nassi, M.; Rogers, B.

1994-01-01

Fusion burning of a D- 3 He mixture in a high density, high magnetic field, compact toroidal experiment (Ignitor) with a high injected power density at the ion cyclotron frequency (ICRF) is investigated. A superthermal tail (with energies exceeding 1 MeV in the central part of the plasma column) is induced in the distribution of the minority 3 He population ( 0 20 m -3 ). This stems from the high value of the peak RF power density absorbed by the minority species (ρ RF ∼ 60 MW/m 3 ) that should be obtained in Ignitor when the total injected power is about 18 MW. This experiment is suitable to begin the study of advanced fusion burning, because of the high plasma currents (I p 3 He fusion powers of the order of 1 MW should be attained. (author) 8 refs., 3 figs

Development of superconducting equipment for fusion device

International Nuclear Information System (INIS)

Konno, Masayuki; Ueda, Toshio; Hiue, Hisaaki; Ohgushi, Kouzou

1993-01-01

At Fuji Electric Co., Ltd., the development of superconductivity was started from 1960, and superconducting equipment for fusion device has been developed for ten years. The superconducting equipment, which is developed for fusion by Fuji Electric Co., Ltd., are able to be grouped in three categories which are current lead, superconducting coil and superconducting bus-line. The current lead is an electrical feeder between a superconducting coil and an electrical power supply. The rated current of developed current lead is 30kA at continuous use and 100kA at short time use respectively. The advanced disk type coil is developed for the toroidal field coil and some coils are developed for critical current measurement. Superconductor is applied to the superconducting bus-line between the superconducting coils and the current leads, and the bus-line is being developed for the Large Helical Device. This report describes an abstract of these equipment. (author)

High precision measurement of fuel density profiles in nuclear fusion plasmas

NARCIS (Netherlands)

Svensson, J.; von Hellermann, M.; Konig, R.

2002-01-01

This paper presents a method for deducing fuel density profiles of nuclear fusion plasmas in realtime during an experiment. A Multi Layer Perceptron (MLP) neural network is used to create a mapping between plasma radiation spectra and indirectly deduced hydrogen isotope densities. By combining

The economic viability of fusion power

International Nuclear Information System (INIS)

Ward, D.J.; Cook, I.; Lechon, Y.; Saez, R.

2005-01-01

Although fusion power is being developed because of its large resource base, low environmental impact and high levels of intrinsic safety, it is important to investigate the economics of a future fusion power plant to check that the electricity produced can, in fact, have a market. The direct cost of electricity of a fusion power plant and its key dependencies on the physics and technology assumptions, are calculated, as are the materials requirements. The other important aspect of costs, the external costs which can arise from effects such as pollution, accidents and waste are also given. Fusion is found to offer the prospect of a new energy source with acceptable direct costs and very low external costs. This places fusion in a strong position in a future energy market, especially one in which environmental constraints become increasingly important

High density plasmas formation in Inertial Confinement Fusion and Astrophysics

International Nuclear Information System (INIS)

Martinez-Val, J. M.; Minguez, E.; Velarde, P.; Perlado, J. M.; Velarde, G.; Bravo, E.; Eliezer, S.; Florido, R.; Garcia Rubiano, J.; Garcia-Senz, D.; Gil de la Fe, J. M.; Leon, P. T.; Martel, P.; Ogando, F.; Piera, M.; Relano, A.; Rodriguez, R.; Garcia, C.; Gonzalez, E.; Lachaise, M.; Oliva, E.

2005-01-01

In inertially confined fusion (ICF), high densities are required to obtain high gains. In Fast Ignition, a high density, low temperature plasma can be obtained during the compression. If the final temperature reached is low enough, the electrons of the plasma can be degenerate. In degenerate plasmas. Bremsstrahlung emission is strongly suppressed an ignition temperature becomes lower than in classical plasmas, which offers a new design window for ICF. The main difficulty of degenerate plasmas in the compression energy needed for high densities. Besides that, the low specific heat of degenerate electrons (as compared to classical values) is also a problem because of the rapid heating of the plasma. Fluid dynamic evolution of supernovae remnants is a very interesting problem in order to predict the thermodynamical conditions achieved in their collision regions. Those conditions have a strong influence in the emission of light and therefore the detection of such events. A laboratory scale system has been designed reproducing the fluid dynamic field in high energy experiments. The evolution of the laboratory system has been calculated with ARWEN code, 2D Radiation CFD that works with Adaptive Mesh Refinement. Results are compared with simulations on the original system obtained with a 3D SPH astrophysical code. New phenomena at the collision plane and scaling of the laboratory magnitudes will be described. Atomic physics for high density plasmas has been studied with participation in experiments to obtain laser produced high density plasmas under NLTE conditions, carried out at LULI. A code, ATOM3R, has been developed which solves rate equations for optically thin plasmas as well as for homogeneous optically thick plasmas making use of escape factors. New improvements in ATOM3R are been done to calculate level populations and opacities for non homogeneous thick plasmas in NLTE, with emphasis in He and H lines for high density plasma diagnosis. Analytical expression

Fusion Engineering Device design description

International Nuclear Information System (INIS)

Flanagan, C.A.; Steiner, D.; Smith, G.E.

1981-12-01

The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein

Fusion engineering device design description

Energy Technology Data Exchange (ETDEWEB)

Flanagan, C.A.; Steiner, D.; Smith, G.E.

1981-12-01

The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein.

Fusion engineering device design description

International Nuclear Information System (INIS)

Flanagan, C.A.; Steiner, D.; Smith, G.E.

1981-12-01

The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein

Graphene-based in-plane micro-supercapacitors with high power and energy densities.

Science.gov (United States)

Wu, Zhong-Shuai; Parvez, Khaled; Feng, Xinliang; Müllen, Klaus

2013-01-01

Micro-supercapacitors are important on-chip micro-power sources for miniaturized electronic devices. Although the performance of micro-supercapacitors has been significantly advanced by fabricating nanostructured materials, developing thin-film manufacture technologies and device architectures, their power or energy densities remain far from those of electrolytic capacitors or lithium thin-film batteries. Here we demonstrate graphene-based in-plane interdigital micro-supercapacitors on arbitrary substrates. The resulting micro-supercapacitors deliver an area capacitance of 80.7 μF cm⁻² and a stack capacitance of 17.9 F cm⁻³. Further, they show a power density of 495 W cm⁻³ that is higher than electrolytic capacitors, and an energy density of 2.5 mWh cm⁻³ that is comparable to lithium thin-film batteries, in association with superior cycling stability. Such microdevices allow for operations at ultrahigh rate up to 1,000 V s⁻¹, three orders of magnitude higher than that of conventional supercapacitors. Micro-supercapacitors with an in-plane geometry have great promise for numerous miniaturized or flexible electronic applications.

Graphene-based in-plane micro-supercapacitors with high power and energy densities

Science.gov (United States)

Wu, Zhong–Shuai; Parvez, Khaled; Feng, Xinliang; Müllen, Klaus

2013-01-01

Micro-supercapacitors are important on-chip micro-power sources for miniaturized electronic devices. Although the performance of micro-supercapacitors has been significantly advanced by fabricating nanostructured materials, developing thin-film manufacture technologies and device architectures, their power or energy densities remain far from those of electrolytic capacitors or lithium thin-film batteries. Here we demonstrate graphene-based in-plane interdigital micro-supercapacitors on arbitrary substrates. The resulting micro-supercapacitors deliver an area capacitance of 80.7 μF cm−2 and a stack capacitance of 17.9 F cm−3. Further, they show a power density of 495 W cm−3 that is higher than electrolytic capacitors, and an energy density of 2.5 mWh cm−3 that is comparable to lithium thin-film batteries, in association with superior cycling stability. Such microdevices allow for operations at ultrahigh rate up to 1,000 V s−1, three orders of magnitude higher than that of conventional supercapacitors. Micro-supercapacitors with an in-plane geometry have great promise for numerous miniaturized or flexible electronic applications. PMID:24042088

High density high performance plasma with internal diffusion barrier in Large Helical Device

International Nuclear Information System (INIS)

Sakamoto, R.; Kobayashi, M.; Miyazawa, J.

2008-10-01

A attractive high density plasma operational regime, namely an internal diffusion barrier (IDB), has been discovered in the intrinsic helical divertor configuration on the Large Helical Device (LHD). The IDB which enables core plasma to access a high density/high pressure regime has been developed. It is revealed that the IDB is reproducibly formed by pellet fueling in the magnetic configurations shifted outward in major radius. Attainable central plasma density exceeds 1x10 21 m -3 . Central pressure reaches 1.5 times atmospheric pressure and the central β value becomes fairly high even at high magnetic field, i.e. β(0)=5.5% at B t =2.57 T. (author)

EMP Fusion

OpenAIRE

KUNTAY, Isık

2010-01-01

This paper introduces a novel fusion scheme, called EMP Fusion, which has the promise of achieving breakeven and realizing commercial fusion power. The method is based on harnessing the power of an electromagnetic pulse generated by the now well-developed flux compression technology. The electromagnetic pulse acts as a means of both heating up the plasma and confining the plasma, eliminating intermediate steps. The EMP Fusion device is simpler compared to other fusion devices and this reduces...

Fueling requirements of super-high-density plasmas towards innovative ignition regime

International Nuclear Information System (INIS)

Sakamoto, Ryuichi; Yamada, Hiroshi

2014-01-01

Highlights: • Self-burning scenario with internal diffusion barrier is investigated. • Peaked density profiles allow to sustain self-burning plasma at lower temperature. • Core fueling beyond internal diffusion barrier is essential to sustain peaked density. • Acceptable pellet size becomes small to prevent fusion out perturbation. • Very high velocity pellet injection beyond 10 km/s is inevitable for this scenario. - Abstract: Super-high-density plasma with an internal diffusion barrier which is observed in the Large Helical Device has been extrapolated to a fusion reactor grade plasma to explore an innovative ignition regime and to clarify essential requirements for pellet fueling. The peaked density profiles due to the internal diffusion barrier formation allow reduction in the required minimum temperature to sustain a self-burning plasma down to 10 keV. Direct core fueling beyond the internal diffusion barrier is essential to sustain the peaked density profile. Furthermore, the acceptable pellet size becomes small in terms of fusion output perturbation because the effective volume of the burning plasma becomes small with the peaked density profile. In order to sustain a self-burning plasma with an internal diffusion barrier, therefore, extremely high velocity pellet injection beyond 10 km/s is inevitable unless another solution to the core fueling is found

Design aspects of a multipurpose fusion power plant for desalination and agrochemical processes

International Nuclear Information System (INIS)

Sabri, Z.A.

1975-02-01

A description is given of the skeletal structure of a multipurpose fusion power plant, designed for desalination and agrochemicals production. The plant is a complex that comprises dual purpose power and desalination units, separation and processing units for recovery of soluble salts in the effluent of the desalination unit, mariculture units for production of algae for food and as food for shrimp and other fish species. The electrical power unit is a two-component fusion device that burns deuterium and helium-3 utilizing a fast fusion cycle

The TITAN Reversed-Field Pinch fusion reactor study

International Nuclear Information System (INIS)

1988-03-01

The TITAN Reversed-Field Pinch (RFP) fusion reactor study is a multi-institutional research effort to determine the technical feasibility and key developmental issues of an RFP fusion reactor, especially at high power density, and to determine the potential economics, operations, safety, and environmental features of high-mass-power-density fusion systems. The TITAN conceptual designs are DT burning, 1000 MWe power reactors based on the RFP confinement concept. The designs are compact, have a high neutron wall loading of 18 MW/m 2 and a mass power density of 700 kWe/tonne. The inherent characteristics of the RFP confinement concept make fusion reactors with such a high mass power density possible. Two different detailed designs have emerged: the TITAN-I lithium-vanadium design, incorporating the integrated-blanket-coil concept; and the TITAN-II aqueous loop-in-pool design with ferritic steel structure. This report contains a collection of 16 papers on the results of the TITAN study which were presented at the International Symposium on Fusion Nuclear Technology. This collection describes the TITAN research effort, and specifically the TITAN-I and TITAN-II designs, summarizing the major results, the key technical issues, and the central conclusions and recommendations. Overall, the basic conclusions are that high-mass power-density fusion reactors appear to be technically feasible even with neutron wall loadings up to 20 MW/m 2 ; that single-piece maintenance of the FPC is possible and advantageous; that the economics of the reactor is enhanced by its compactness; and the safety and environmental features need not to be sacrificed in high-power-density designs. The fact that two design approaches have emerged, and others may also be possible, in some sense indicates the robustness of the general findings

Neutronic analysis of fusion tokamak devices by PHITS

International Nuclear Information System (INIS)

Sukegawa, Atsuhiko M.; Takiyoshi, Kouji; Amano, Toshio; Kawasaki, Hiromitsu; Okuno, Koichi

2011-01-01

A complete 3D neutronic analysis by PHITS (Particle and Heavy Ion Transport code System) has been performed for fusion tokamak devices such as JT-60U device and JT-60 Superconducting tokamak device (JT-60 Super Advanced). The mono-energetic neutrons (E n =2.45 MeV) of the DD fusion devices are used for the neutron source in the analysis. The visual neutron flux distribution for the estimation of the port streaming and the dose rate around the fusion tokamak devices has been calculated by the PHITS. The PHITS analysis makes it clear that the effect of the port streaming of superconducting fusion tokamak device with the cryostat is crucial and the calculated neutron spectrum results by PHITS agree with the MCNP-4C2 results. (author)

Fusion power plant studies in Europe

International Nuclear Information System (INIS)

Maisonnier, D.

2007-01-01

The European fusion programme is reactor oriented and it is aimed at the successive demonstration of the scientific, the technological and the economic feasibility of fusion power. For a reactor-oriented fusion development programme, it is essential to have a clear idea of the ultimate goal of the programme, namely a series of models of fusion power plants, in order to define the correct strategy and to assess the pertinence of the on-going activities. The European Power Plant Conceptual Study (PPCS) has been a study of conceptual designs for commercial fusion power plants. It focused on five power plant models, named PPCS A, B, AB, C and D, which are illustrative of a wider spectrum of possibilities. They are all based on the tokamak concept and they have approximately the same net electrical power output, 1500 MWe. These span a range from relatively near-term, based on limited technology and plasma physics extrapolations, to an advanced conception. All five PPCS plant models differ substantially from the models that formed the basis of earlier European studies. They also differ from one another, which lead to differences in economic performance and in the details of safety and environmental impacts. The main emphasis of the PPCS was on system integration. Systems analyses were used to produce self-consistent plant parameter sets with approximately optimal economic characteristics for all models. In the PPCS models, the favourable, inherent, features of fusion have been exploited to provide substantial safety and environmental advantages. The broad features of the safety and environmental conclusions of previous studies have been confirmed and demonstrated with increased confidence. The PPCS study highlighted the need for specific design and R and D activities, in addition to those already underway within the European long term R and D programme, as well as the need to clarify the concept of DEMO, the device that will bridge the gap between ITER and the first

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

Science.gov (United States)

Sharafat, Shahram; Ghoniem, Nasr M.; Anderson, Michael; Williams, Brian; Blanchard, Jake; Snead, Lance; HAPL Team

2005-12-01

The high average power laser program is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first wall (FW) will be subject to high energy density radiation and high doses of high energy helium implantation. Tungsten has been identified as the candidate material for a FW armor. The fundamental concern is long term thermo-mechanical survivability of the armor against the effects of high temperature pulsed operation and exfoliation due to the retention of implanted helium. Even if a solid tungsten armor coating would survive the high temperature cyclic operation with minimal failure, the high helium implantation and retention would result in unacceptable material loss rates. Micro-engineered materials, such as castellated structures, plasma sprayed nano-porous coatings and refractory foams are suggested as a first wall armor material to address these fundamental concerns. A micro-engineered FW armor would have to be designed with specific geometric features that tolerate high cyclic heating loads and recycle most of the implanted helium without any significant failure. Micro-engineered materials are briefly reviewed. In particular, plasma-sprayed nano-porous tungsten and tungsten foams are assessed for their potential to accommodate inertial fusion specific loads. Tests show that nano-porous plasma spray coatings can be manufactured with high permeability to helium gas, while retaining relatively high thermal conductivities. Tungsten foams where shown to be able to overcome thermo-mechanical loads by cell rotation and deformation. Helium implantation tests have shown, that pulsed implantation and heating releases significant levels of implanted helium. Helium implantation and release from tungsten was modeled using an expanded kinetic rate theory, to include the effects of pulsed implantations and thermal cycles. Although, significant challenges remain micro-engineered materials are shown to constitute potential

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

International Nuclear Information System (INIS)

Sharafat, Shahram; Ghoniem, Nasr M.; Anderson, Michael; Williams, Brian; Blanchard, Jake; Snead, Lance

2005-01-01

The high average power laser program is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first wall (FW) will be subject to high energy density radiation and high doses of high energy helium implantation. Tungsten has been identified as the candidate material for a FW armor. The fundamental concern is long term thermo-mechanical survivability of the armor against the effects of high temperature pulsed operation and exfoliation due to the retention of implanted helium. Even if a solid tungsten armor coating would survive the high temperature cyclic operation with minimal failure, the high helium implantation and retention would result in unacceptable material loss rates. Micro-engineered materials, such as castellated structures, plasma sprayed nano-porous coatings and refractory foams are suggested as a first wall armor material to address these fundamental concerns. A micro-engineered FW armor would have to be designed with specific geometric features that tolerate high cyclic heating loads and recycle most of the implanted helium without any significant failure. Micro-engineered materials are briefly reviewed. In particular, plasma-sprayed nano-porous tungsten and tungsten foams are assessed for their potential to accommodate inertial fusion specific loads. Tests show that nano-porous plasma spray coatings can be manufactured with high permeability to helium gas, while retaining relatively high thermal conductivities. Tungsten foams where shown to be able to overcome thermo-mechanical loads by cell rotation and deformation. Helium implantation tests have shown, that pulsed implantation and heating releases significant levels of implanted helium. Helium implantation and release from tungsten was modeled using an expanded kinetic rate theory, to include the effects of pulsed implantations and thermal cycles. Although, significant challenges remain micro-engineered materials are shown to constitute potential

Prospect of laser fusion power generation

International Nuclear Information System (INIS)

Nakai, Sadao

1998-01-01

Inertial fusion ignition, burn and energy gain are expected to be achieved within the first decade of next century with new Megajoule laser facilities which are under construction in the USA and France. Fusion reactor design studies indicate that Inertial Fusion Energy(IFE) power plants are technically feasible and have attractive safety and environmental features. The recent progress on implosion physics and relevant technologies require us to consider a strategic approach toward IFE development. The design study for a laser fusion power plant KOYO has been conducted as a joint program of universities, national laboratories and industries in Japan and also with international collaborations. The progress of high power laser technology gives us feasible project toward a laser driven IFE Power Plant. The technical breakthrough in the field of diode pumped solid state laser (DPSSL) has opened wide application of power laser to industrial technologies. Laser fusion energy development will be proceeded jointly with industrial photonics research and development. International collaborations are also promoted for efficient progress and activation of R and D on advanced technologies which are required for IFE and also useful for modern industries. (author). 7 refs., 1 tab., 7 figs

Inertial fusion with ultra-powerful lasers

International Nuclear Information System (INIS)

Tabak, M.; Hammer, J.; Glinsky, M.; Kruer, W.; Wilks, S.; Woodworth, J.; Campbell, E.M.; Perry, M.D.; Mason, R.

1993-10-01

Ultra-high intensity lasers can be used to ignite ICF capsules with a few tens of kilojoules of light and can lead to high gain with as little as 100 kilojoules of incident laser light. We propose a scheme with three phases. First, a capsule is imploded as in the conventional approach to inertial fusion to assemble a high density fuel configuration. Second, a hole is bored through capsule corona composed of ablated material, pushing critical density close to the high density core of the capsule, by employing the ponderomotive force associated with high intensity laser light. Finally, the fuel is ignited by suprathermal electrons, produced in the high intensity laser plasma interactions, which propagate from critical density to this high density core. This paper reviews two models of energy gain in ICF capsules and explains why ultra-high intensity lasers allow access to the model producing the higher gains. This new scheme also drastically reduces the difficulty of the implosion and thereby allows lower quality fabrication and less stringent beam quality and symmetry requirements from the implosion driver. The difficulty of the fusion scheme is transferred to the technological difficulty of producing the ultra-high-intensity laser and of transporting this energy to the fuel

Protector in a nuclear fusion device

International Nuclear Information System (INIS)

Furukawa, Masayuki; Yamane, Katsumi; Niwa, Sadahiko; Ogata, Fumio; Masuda, Jun-ichi.

1975-01-01

Object: To block an abnormal voltage, which shifts from plasma to coil or power supply by means of action of mutual induction, by a circuit utilizing non-linear impedance elements. Structure: The nuclear fusion device includes a current transformer coil, a vertical field coil and a plasma circuit, with a non-linear impedance element disposed in parallel with at least the current transformer coil, said impedance element being disposed in parallel with a short-circuiting switch, relative to the abnormal voltage moving from the plasma by means of action of mutual induction. (Kamimura, M.)

Inertial fusion energy power plant design using the Compact Torus Accelerator: HYLIFE-CT

International Nuclear Information System (INIS)

Moir, R.W.; Hammer, J.H.; Hartman, C.W.; Leber, R.L.; Logan, B.G.; Petzoldt, R.W.; Tabak, M.; Tobin, M.T.; Bieri, R.L.; Hoffman, M.A.

1992-01-01

The Compact Torus Accelerator (CTA), under development at Lawrence Livermore National Laboratory, offers the promise of a low-cost, high-efficiency, high energy, high-power-density driver for ICF and MICF (Magnetically Insulated ICF) type fusion systems. A CTA with 100 MJ driver capacitor bank energy is predicted to deliver ∼30 MJ CT kinetic energy to a 1 cm 2 target in several nanoseconds for a power density of ∼10 16 watts/cm 2 . The estimated cost of delivered energy is ∼3$/Joule, or $100M for 30 MJ. This driver appears to be cost-effective and, in this regard, is virtually alone among IFE drivers. We discuss indirect-drive ICF with a DT fusion energy gain Q = 70 for a total yield of 2 GJ. The CT can be guided to the target inside a several-meter-long disposable cone made of frozen Li 2 BeF 4 , the same material as the coolant. We have designed a power plant including CT injection, target emplacement, containment, energy recovery, and tritium breeding. The cost of electricity is predicted to be 4.8 cents/kWh, which is competitive with future coal and nuclear costs

The fusion-FEM: 0,75 MW of mm-wave power

Energy Technology Data Exchange (ETDEWEB)

Smeets, P.H.M.; Bongers, W.A.; Brons, S.; Geer, C.A.J. van der; Lingier, K.L.; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Sterk, A.B.; Verhoeven, A.G.A.; Urbanus, W.H. [FOM Inst. voor Plasmafysica ' Rijnhuizen' , Nieuwegein (Netherlands); Bratman, V.L.; Denisov, G.G.; Savilov, A.V. [Inst. of Applied Physics, Nizhny Novgorod (Russian Federation); Caplan, M. [Lawrence Livermore National Lab., CA (United States); Varfolomeev, A.A. [Russian Research Center ' Kurchatov Inst.' , Moscow (Russian Federation)

1998-07-01

The free-electron maser for fusion applications (Fusion-FEM) is the prototype for a high power, rapid tunable mm-wave source. The basic parameters such as frequency range (130 - 260 GHz) and output power (1 MW) are dedicated to Electron Cyclotron Resonance applications on future plasma fusion research devices, such as ITER. In October 1996 the electron beam was successfully accelerated and transported through the undulator and the mm-wave cavity. Loss currents are below 0.05 %. In October 1997 first lasing was achieved. The mm-wave output power has been measured at various frequencies and for various electron beam currents and energies. The highest output power reached so far is 730 kW at 205 GHz, for an electron beam of 7.2 A and 1.77 MeV. Both output power and start-up time correspond well with simulation results. The output beam has a Gaussian mode content of more than 99.8 % for all operating frequencies. So far, the pulse length was limited to 12{mu}s, because the electron beam recovery system was not yet installed. This system, an electron decelerator and a 3-stage depressed collector, is presently under construction. It serves to recover the charge and energy of the spend electron beam. In this paper we will address some aspects of the design of the collector. (author)

The fusion-FEM: 0,75 MW of mm-wave power

International Nuclear Information System (INIS)

Smeets, P.H.M.; Bongers, W.A.; Brons, S.; Geer, C.A.J. van der; Lingier, K.L.; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Sterk, A.B.; Verhoeven, A.G.A.; Urbanus, W.H.; Bratman, V.L.; Denisov, G.G.; Savilov, A.V.; Caplan, M.; Varfolomeev, A.A.

1998-01-01

The free-electron maser for fusion applications (Fusion-FEM) is the prototype for a high power, rapid tunable mm-wave source. The basic parameters such as frequency range (130 - 260 GHz) and output power (1 MW) are dedicated to Electron Cyclotron Resonance applications on future plasma fusion research devices, such as ITER. In October 1996 the electron beam was successfully accelerated and transported through the undulator and the mm-wave cavity. Loss currents are below 0.05 %. In October 1997 first lasing was achieved. The mm-wave output power has been measured at various frequencies and for various electron beam currents and energies. The highest output power reached so far is 730 kW at 205 GHz, for an electron beam of 7.2 A and 1.77 MeV. Both output power and start-up time correspond well with simulation results. The output beam has a Gaussian mode content of more than 99.8 % for all operating frequencies. So far, the pulse length was limited to 12μs, because the electron beam recovery system was not yet installed. This system, an electron decelerator and a 3-stage depressed collector, is presently under construction. It serves to recover the charge and energy of the spend electron beam. In this paper we will address some aspects of the design of the collector. (author)

Transport analysis of high radiation and high density plasmas in the ASDEX Upgrade tokamak

Directory of Open Access Journals (Sweden)

Casali L.

2014-01-01

Full Text Available Future fusion reactors, foreseen in the “European road map” such as DEMO, will operate under more demanding conditions compared to present devices. They will require high divertor and core radiation by impurity seeding to reduce heat loads on divertor target plates. In addition, DEMO will have to work at high core densities to reach adequate fusion performance. The performance of fusion reactors depends on three essential parameters: temperature, density and energy confinement time. The latter characterizes the loss rate due to both radiation and transport processes. The DEMO foreseen scenarios described above were not investigated so far, but are now addressed at the ASDEX Upgrade tokamak. In this work we present the transport analysis of such scenarios. Plasma with high radiation by impurity seeding: transport analysis taking into account the radiation distribution shows no change in transport during impurity seeding. The observed confinement improvement is an effect of higher pedestal temperatures which extend to the core via stiffness. A non coronal radiation model was developed and compared to the bolometric measurements in order to provide a reliable radiation profile for transport calculations. High density plasmas with pellets: the analysis of kinetic profiles reveals a transient phase at the start of the pellet fuelling due to a slower density build up compared to the temperature decrease. The low particle diffusion can explain the confinement behaviour.

Workshop on High Power ICH Antenna Designs for High Density Tokamaks

Science.gov (United States)

Aamodt, R. E.

1990-02-01

A workshop in high power ICH antenna designs for high density tokamaks was held to: (1) review the data base relevant to the high power heating of high density tokamaks; (2) identify the important issues which need to be addressed in order to ensure the success of the ICRF programs on CIT and Alcator C-MOD; and (3) recommend approaches for resolving the issues in a timely realistic manner. Some specific performance goals for the antenna system define a successful design effort. Simply stated these goals are: couple the specified power per antenna into the desired ion species; produce no more than an acceptable level of RF auxiliary power induced impurities; and have a mechanical structure which safely survives the thermal, mechanical and radiation stresses in the relevant environment. These goals are intimately coupled and difficult tradeoffs between scientific and engineering constraints have to be made.

Inertial Fusion Power Plant Concept of Operations and Maintenance

Energy Technology Data Exchange (ETDEWEB)

Anklam, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knutson, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dunne, A. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kasper, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sheehan, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lang, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Roberts, V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mau, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-01-15

Parsons and LLNL scientists and engineers performed design and engineering work for power plant pre-conceptual designs based on the anticipated laser fusion demonstrations at the National Ignition Facility (NIF). Work included identifying concepts of operations and maintenance (O&M) and associated requirements relevant to fusion power plant systems analysis. A laser fusion power plant would incorporate a large process and power conversion facility with a laser system and fusion engine serving as the heat source, based in part on some of the systems and technologies advanced at NIF. Process operations would be similar in scope to those used in chemical, oil refinery, and nuclear waste processing facilities, while power conversion operations would be similar to those used in commercial thermal power plants. While some aspects of the tritium fuel cycle can be based on existing technologies, many aspects of a laser fusion power plant presents several important and unique O&M requirements that demand new solutions. For example, onsite recovery of tritium; unique remote material handling systems for use in areas with high radiation, radioactive materials, or high temperatures; a five-year fusion engine target chamber replacement cycle with other annual and multi-year cycles anticipated for major maintenance of other systems, structures, and components (SSC); and unique SSC for fusion target waste recycling streams. This paper describes fusion power plant O&M concepts and requirements, how O&M requirements could be met in design, and how basic organizational and planning issues can be addressed for a safe, reliable, economic, and feasible fusion power plant.

Study of lower hybrid current drive system in tokamak fusion devices

Energy Technology Data Exchange (ETDEWEB)

Maebara, Sunao [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-01-01

This report describes R and D of a high-power klystron, RF vacuum window, low-outgassing antenna and a front module for a plasma-facing antenna aiming the 5 GHz Lower Hybrid Current Drive (LHCD) system for the next Tokamak Fusion Device. 5 GHz klystron with a low-perveances of 0.7 {mu}P is designed for a high-power and a high-efficiency, the output-power of 715 kW and the efficiency of 63%, which are beyond the conventional design scaling of 450 kW-45%, are performed using the prototype klystron which operates at the pulse duration of 15 {mu}sec. A new pillbox window, which has an oversized length in both the axial and the radial direction, are designed to reduce the RF power density and the electric field strength at the ceramics. It is evaluated that the power capability by cooling edge of ceramics is 1 MW with continuous-wave operation. The antenna module using Dispersion Strengthened Copper which combines high mechanical property up to 500degC with high thermal conductivity, are developed for a low-outgassing antenna in a steady state operation. It is found that the outgassing rate is in the lower range of 4x10{sup -6} Pam{sup 3}/sm{sup 2} at the module temperature of 300degC, which requires no active vacuum pumping of the LHCD antenna. A front module using Carbon Fiber Composite (CFC) are fabricated and tested for a plasma facing antenna which has a high heat-resistive. Stationary operation of the CFC module with water cooling is performed at the RF power of 46 MWm{sup -2} (about 2 times higher than the design value) during 1000 sec, it is found that the outgassing rate is less than 10{sup -5} Pam{sup 3}/sm{sup 2} which is low enough for an antenna material. (author)

Reinvestigation of the charge density distribution in arc discharge fusion system

Energy Technology Data Exchange (ETDEWEB)

Sheng, Lin Horng; Yee, Lee Kim; Nan, Phua Yeong; Thung, Yong Yun; Khok, Yong Thian; Rahman, Faidz Abd [Centre of Photonics and Advance Material, Universiti Tunku Abdul Rahman Kuala Lumpur (Malaysia)

2015-04-24

A continual arc discharge system has been setup and the light intensity of arc discharge has been profiled. The mathematical model of local energy density distribution in arc discharge fusion has been simulated which is in good qualitative agreement with light intensity profile of arc discharge in the experiments. Eventually, the local energy density distribution of arc discharge system is able to be precisely manipulated to act as heat source in the fabrication of fused fiber devices.

Reinvestigation of the charge density distribution in arc discharge fusion system

International Nuclear Information System (INIS)

Sheng, Lin Horng; Yee, Lee Kim; Nan, Phua Yeong; Thung, Yong Yun; Khok, Yong Thian; Rahman, Faidz Abd

2015-01-01

A continual arc discharge system has been setup and the light intensity of arc discharge has been profiled. The mathematical model of local energy density distribution in arc discharge fusion has been simulated which is in good qualitative agreement with light intensity profile of arc discharge in the experiments. Eventually, the local energy density distribution of arc discharge system is able to be precisely manipulated to act as heat source in the fabrication of fused fiber devices

Parameter scaling toward high-energy density in a quasi-steady flow Z-pinch

Science.gov (United States)

Hughes, M. C.; Shumlak, U.; Nelson, B. A.; Golingo, R. P.; Claveau, E. L.; Doty, S. A.; Forbes, E. G.; Kim, B.; Ross, M. P.

2016-10-01

Sheared axial flows are utilized by the ZaP Flow Z-Pinch Experiment to stabilize MHD instabilities. The pinches formed are 50 cm long with radii ranging from 0.3 to 1.0 cm. The plasma is generated in a coaxial acceleration region, similar to a Marshall gun, which provides a steady supply of plasma for approximately 100 us. The power to the plasma is partially decoupled between the acceleration and pinch assembly regions through the use of separate power supplies. Adiabatic scaling of the Bennett relation gives targets for future devices to reach high-energy density conditions or fusion reactors. The applicability of an adiabatic assumption is explored and work is done experimentally to clarify the plasma compression process, which may be more generally polytropic. The device is capable of a much larger parameter space than previous machine iterations, allowing flexibility in the initial conditions of the compression process to preserve stability. This work is supported by DoE FES and NNSA.

High-energy power capacitors, their applied technology and the trends

International Nuclear Information System (INIS)

2012-01-01

High-voltage and high-energy-density power capacitors called high-power ones such as film or electrolytic capacitors, have been used in large quantities for the pulse power technology such as an impulse current or voltage generator and a laser power supply, and for the power electronics one with progress of the power semiconductor device and the inverter technology. Recently, electric double layer capacitors (EDLC) with remarkable technical progress have been applied for the equipments of electric power and industrial field for the purpose of energy saving or electric power quality improvement, which have come to link to the electric power system. Thus, using a lot of high-power capacitors near our life would require to know the structure, the principle and the characteristic of capacitors, and also to consider suitable directions for use, maintenance and safety and so on, when carrying out a system and a facility design. In the technical report, while describing the dielectric and the feature of some high-power capacitors, and introducing the application examples to the laser-fusion power supply and some systems with EDLC, the trend of standardization of EDLC and the directivity of the examination about installation and maintenance of the applied equipments are described. (author)

Powerful lasers for thermonuclear fusion

International Nuclear Information System (INIS)

Basov, N.; Krokhin, O.; Sklizkov, G.; Fedotov, S.

1977-01-01

The parameters are discussed of the radiation of powerful lasers (internal energy of the plasma determined by the volume, density and temperature of the plasma, duration of the heating pulse, focusing of the laser pulse energy in a small volume of matter, radiation contrast) for attaining an effective thermonuclear fusion at minimum microexplosion energy. A survey is given of the methods of shaping laser pulses with limit parameters, and the principle of the construction of powerful laser systems is described. The general diagram and parameters are given of the Delfin thermonuclear apparatus and a diagram is presented of the focusing system of high luminosity for spherical plasma heating using spherical mirrors. A diagram is presented of the vacuum chamber and of the complex diagnostic apparatus for determining the basic parameters of thermonuclear plasma in the Delfin apparatus. The prospects are indicated of the further development of thermonuclear laser apparatus with neodymium and CO 2 lasers. (B.S.)

Workshop on high power ICH antenna designs for high density tokamaks

International Nuclear Information System (INIS)

Aamodt, R.E.

1990-01-01

A workshop in high power ICH antenna designs for high density tokamaks was held in Boulder, Colorado on January 31 through February 2, 1990. The purposes of the workshop were to: (1) review the data base relevant to the high power heating of high density tokamaks; (2) identify the important issues which need to be addressed in order to ensure the success of the ICRF programs on CIT and Alcator C-MOD; and (3) recommend approaches for resolving the issues in a timely realistic manner. Some specific performance goals for the antenna system define a successful design effort. Simply stated these goals are: couple the specified power per antenna into the desired ion species; produce no more than an acceptable level of rf auxiliary power induced impurities; and have a mechanical structure which safely survives the thermal, mechanical and radiation stresses in the relevant environment. These goals are intimately coupled and difficult tradeoffs between scientific and engineering constraints have to be made

3D macroporous graphene frameworks for supercapacitors with high energy and power densities.

Science.gov (United States)

Choi, Bong Gill; Yang, Minho; Hong, Won Hi; Choi, Jang Wook; Huh, Yun Suk

2012-05-22

In order to develop energy storage devices with high power and energy densities, electrodes should hold well-defined pathways for efficient ionic and electronic transport. Herein, we demonstrate high-performance supercapacitors by building a three-dimensional (3D) macroporous structure that consists of chemically modified graphene (CMG). These 3D macroporous electrodes, namely, embossed-CMG (e-CMG) films, were fabricated by using polystyrene colloidal particles as a sacrificial template. Furthermore, for further capacitance boost, a thin layer of MnO(2) was additionally deposited onto e-CMG. The porous graphene structure with a large surface area facilitates fast ionic transport within the electrode while preserving decent electronic conductivity and thus endows MnO(2)/e-CMG composite electrodes with excellent electrochemical properties such as a specific capacitance of 389 F/g at 1 A/g and 97.7% capacitance retention upon a current increase to 35 A/g. Moreover, when the MnO(2)/e-CMG composite electrode was asymmetrically assembled with an e-CMG electrode, the assembled full cell shows remarkable cell performance: energy density of 44 Wh/kg, power density of 25 kW/kg, and excellent cycle life.

Micro/Nano Fabricated Solid-State Thermoelectric Generator Devices for Integrated High Voltage Power Sources

Science.gov (United States)

Fleurial, J.-P.; Ryan, M. A.; Snyder, G. J.; Huang, C.-K.; Whitacre, J. F.; Patel, J.; Lim, J.; Borshchevsky, A.

2002-01-01

Deep space missions have a strong need for compact, high power density, reliable and long life electrical power generation and storage under extreme temperature conditions. Except for electrochemical batteries and solar cells, there are currently no available miniaturized power sources. Conventional power generators devices become inefficient in extreme environments (such as encountered in Mars, Venus or outer planet missions) and rechargeable energy storage devices can only be operated in a narrow temperature range thereby limiting mission duration. The planned development of much smaller spacecrafts incorporating a variety of micro/nanodevices and miniature vehicles will require novel, reliable power technologies. It is also expected that such micro power sources could have a wide range of terrestrial applications, in particular when the limited lifetime and environmental limitations of batteries are key factors. Advanced solid-state thermoelectric combined with radioisotope or waste heat sources and low profile energy storage devices are ideally suited for these applications. The Jet Propulsion Laboratory has been actively pursuing the development of thermoelectric micro/nanodevices that can be fabricated using a combination of electrochemical deposition and integrated circuit processing techniques. Some of the technical challenges associated with these micro/nanodevice concepts, their expected level of performance and experimental fabrication and testing results to date are presented and discussed.

Optimization of power and energy densities in supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Robinson, David B. [Sandia National Laboratories, PO Box 969 MS 9291, Livermore, CA 94551 (United States)

2010-06-01

Supercapacitors use nanoporous electrodes to store large amounts of charge on their high surface areas, and use the ions in electrolytes to carry charge into the pores. Their high power density makes them a potentially useful complement to batteries. However, ion transport through long, narrow channels still limits power and efficiency in these devices. Proper design can mitigate this. Current collector geometry must also be considered once this is done. Here, De Levie's model for porous electrodes is applied to quantitatively predict device performance and to propose optimal device designs for given specifications. Effects unique to nanoscale pores are considered, including that pores may not have enough salt to fully charge. Supercapacitors are of value for electric vehicles, portable electronics, and power conditioning in electrical grids with distributed renewable sources, and that value will increase as new device fabrication methods are developed and proper design accommodates those improvements. Example design outlines for vehicle applications are proposed and compared. (author)

High-Z plasma facing components in fusion devices: boundary conditions and operational experiences

Science.gov (United States)

Neu, R.

2006-04-01

In present day fusion devices optimization of the performance and experimental freedom motivates the use of low-Z plasma facing materials (PFMs). However, in a future fusion reactor, for economic reasons, a sufficient lifetime of the first wall components is essential. Additionally, tritium retention has to be small to meet safety requirements. Tungsten appears to be the most realistic material choice for reactor plasma facing components (PFCs) because it exhibits the lowest erosion. But besides this there are a lot of criteria which have to be fulfilled simultaneously in a reactor. Results from present day devices and from laboratory experiments confirm the advantages of high-Z PFMs but also point to operational restrictions, when using them as PFCs. These are associated with the central impurity concentration, which is determined by the sputtering yield, the penetration of the impurities and their transport within the confined plasma. The restrictions could exclude successful operation of a reactor, but concomitantly there exist remedies to ameliorate their impact. Obviously some price has to be paid in terms of reduced performance but lacking of materials or concepts which could substitute high-Z PFCs, emphasis has to be put on the development and optimization of reactor-relevant scenarios which incorporate the experiences and measures.

High-Z plasma facing components in fusion devices: boundary conditions and operational experiences

International Nuclear Information System (INIS)

Neu, R.

2006-01-01

In present day fusion devices optimization of the performance and experimental freedom motivates the use of low-Z plasma facing materials (PFMs). However, in a future fusion reactor, for economic reasons, a sufficient lifetime of the first wall components is essential. Additionally, tritium retention has to be small to meet safety requirements. Tungsten appears to be the most realistic material choice for reactor plasma facing components (PFCs) because it exhibits the lowest erosion. But besides this there are a lot of criteria which have to be fulfilled simultaneously in a reactor. Results from present day devices and from laboratory experiments confirm the advantages of high-Z PFMs but also point to operational restrictions, when using them as PFCs. These are associated with the central impurity concentration, which is determined by the sputtering yield, the penetration of the impurities and their transport within the confined plasma. The restrictions could exclude successful operation of a reactor, but concomitantly there exist remedies to ameliorate their impact. Obviously some price has to be paid in terms of reduced performance but lacking of materials or concepts which could substitute high-Z PFCs, emphasis has to be put on the development and optimization of reactor-relevant scenarios which incorporate the experiences and measures

Towards fusion power

International Nuclear Information System (INIS)

Venkataraman, G.

1975-01-01

An attempt has been made to present general but broad review of the recent developments in the field of plasma physics and its application to fusion power. The first chapter describes the fusion reactions and fusion power systems. The second chapter deals in detail with production and behaviour of plasma, screening, oscillations, instability, energy losses, temperature effects, etc. Magnetic confinements, including pinch systems, toroidal systems such as Tokamac and stellarator, minor machine, etc. are discussed in detail in chapter III. Laser produced plasma, laser implosion and problems associated with it and future prospects are explained in chapter IV. Chapter V is devoted entirely to the various aspects of hybrid systems. The last chapter throws light on problems of fusion technology, such as plasma heating, vacuum requirements, radiation damage, choice of materials, blanket problems, hazards of fusion reactions, etc. (K.B.)

A high power, tunable free electron maser for fusion

Energy Technology Data Exchange (ETDEWEB)

Urbanus, W.H.; Bratman, V.L.; Bongers, W.A.; Caplan, M.; Denisov, G.G.; Geer, C.A.J. van der; Manintveld, P.; Militsyn, B.; Oomens, A.A.M.; Poelman, A.J.; Plomp, J.; Pluygers, J.; Savilov, A.V.; Smeets, P.H.M.; Sterk, A.B.; Verhoeven, A.G.A

2001-01-01

The Fusion-FEM experiment, a high-power, electrostatic free-electron maser being built at the FOM-Institute for Plasma Physics 'Rijnhuizen', is operated at various frequencies. So far, experiments were done without a depressed collector, and the pulse length was limited to 12 {mu}s. Nevertheless, many aspects of generation of mm-wave power have been explored, such as the dependency on the electron beam energy and beam current, and cavity settings such as the feedback coefficient. An output power of 730 kW at 206 GHz is generated with a 7.2 A, 1.77 MeV electron beam, and 360 kW at 167 GHz is generated with a 7.4 A, 1.61 MeV electron beam. It is shown experimentally and by simulations that, depending on the electron beam energy, the FEM can operate in single-frequency regime. The next step of the FEM experiment is to reach a pulse length of 100 ms. The major part of the beam line, the high voltage systems, and the collector have been completed. The undulator and mm-wave cavity are now at high voltage (2 MV). The new mm-wave transmission line, which transports the mm-wave output power from the high-voltage terminal to ground and outside the pressure tank, has been tested at low power.

High power laser exciter accelerators

International Nuclear Information System (INIS)

Martin, T.H.

1975-01-01

Recent developments in untriggered oil and water switching now permit the construction of compact, high energy density pulsed power sources for laser excitation. These accelerators, developed principally for electron beam fusion studies, appear adaptable to laser excitation and will provide electron beams of 10 13 to 10 14 W in the next several years. The accelerators proposed for e-beam fusion essentially concentrate the available power from the outside edge of a disk into the central region where the electron beam is formed. One of the main problem areas, that of power flow at the vacuum diode insulator, is greatly alleviated by the multiplicity of electron beams that are allowable for laser excitation. A proposal is made whereby the disk-shaped pulsed power sections are stacked vertically to form a series of radially flowing electron beams to excite the laser gas volume. (auth)

System constitution of plasma high frequency heating device and element equipment

International Nuclear Information System (INIS)

Nagashima, Takashi

1988-01-01

On the high frequency heating device used for nuclear fusion experiment, the system constitution and the main items of development for the element equipment are described. As for the high frequency heating device, large technical progress was observed in the past 10 years as the second stage heating for tokamaks and one of the main means of current drive. At present, three frequency zones are regarded as promising for plasma high frequency heating in large nuclear fusion devices, and the experiment of 10 MW class is in progress at JT-60, JET and so on. There are electron cyclotron heating, lower hybrid resonance frequency heating and ion cyclotron range of frquency heating. The basic constitution of these heating devices includes a high frequency source, a transmission system, a connection system, and a common system for control, cooling, record and others. The ECH device using gyrotrons of several tens GHz, the LHRF heating device using large power klystrons up to several GHz and the ICRF heating device up to 200 MHz are briefly explained. The main element equipments composing the high frequency heating systems of several tens MW are discussed. (Kako, I.)

Engineering challenges encountered in the design of the ELMO BUMPY TORUS proof-of-principle fusion device

International Nuclear Information System (INIS)

Dillow, C.F.; Imster, H.F.

1982-01-01

This paper first provides a summary of the history and current status of the Elmo Bumpy Torus (EBT) fusion concept. A brief description of the EBT-P is then provided in which the many unique features of this fusion device are highlighted. This description will provide the technical background for the following discussions of some of the more challenging mechanical engineering problems encountered to date in the evolution of the EBT-P design. The problems discussed are: optimization of the device primary structure design, optimization of the superconducting magnet x-ray shield design, design of the liquid helium supply and distribution system, and selection of high vacuum seals and pumps and their protection from the high power microwave environment. The common challenge in each of these design issues was to assure adequate performance at minimum cost

The development of controlled nuclear fusion

International Nuclear Information System (INIS)

Pease, R.S.

1978-01-01

The high temperature conditions needed in a controlled nuclear fusion reactor are now being approached in experiments using magnetic fields to confine and isolate the plasma, especially in systems of the tokamak type. The underlying reasons for the successes are discussed and it is concluded that the remaining advances needed in temperature and thermal insulation may well be achieved in new large tokamak experiments now under construction. Comparable progress is being made also in inertial confinement systems; key experiments on achieving the required super-high densities with high-powered pulsed laser systems are about to commence. To achieve fusion reactors will require the combination of three major disciplines: plasma physics, electromechanical engineering and nuclear engineering. Proposals have been made for an international study group to be set up under the IAEA auspices to consider technical objectives and the nature of the next large fusion device which could be constructed internationally, and in which this synthesis could be attempted. (author)

On the role of turbulence on momentum redistribution in fusion devices

International Nuclear Information System (INIS)

Hidalgo, C.

2005-01-01

The mechanisms underlying the generation of plasma flows play a crucial role in understanding key issues on transport in magnetically confined plasmas. It is well known the importance of driving shear in plasma rotation in the development of transport barriers. Rotation can be driven by external forces such as momentum from Neutral Beam Injection (NBI). However, in large scale devices like ITER (where the available NBI power is limited and the energy of injected neutrals must be high to reach the core plasma region) the NBI driven rotation will be limited. Then, it is important to study the possible role of other mechanisms which can drive plasma rotation. The amplitude of parallel flow measured in the scrape-off layer (SOL) is significantly larger than those resulting from simulations. Recent experiments have pointed out the possible influence of turbulence in explaining a component of the anomalous flows observed in the plasma boundary region. In the plasma core region, evidence of anomalous toroidal momentum transport has been reported. Different mechanisms have been proposed to explain these results, including neoclassical effects, turbulence driven models and fast particle effects. The response of toroidal rotation to near-perpendicular NB injection on JT-60U has been interpreted on the basis of the influence of loss of high-energy particles. The flow reversal observed in the CHS stellarator can be explained by the spontaneous flow driven by large radial electric fields. Neoclassical effects can also play an import role. Recent experiments in the TJ-II stellarator have shown that the generation of spontaneous perpendicular sheared flows requires a minimum plasma density. Near this critical density, the level of edge turbulent transport and the turbulent kinetic energy significantly increases in the plasma edge. Experimental results also show significant turbulent parallel forces at plasma densities above the threshold value to trigger perpendicular ExB sheared

Revised assessments of the economics of fusion power

International Nuclear Information System (INIS)

Han, W.E.; Ward, D.J.

2009-01-01

Although fusion power is being developed because of its large resource base, low environmental impact and high levels of intrinsic safety, it is also important to investigate the economics of a future fusion power plant in order to assess the potential market for the electricity produced. As part of the PPCS (Power Plant Conceptual Study) in Europe, published in 2005, an assessment was made of the likely economic performance of the range of fusion power plant concepts studied. Since that time, new work has been carried out, within the fusion programme, and particularly in the EU DEMO study, that changes a number of the important assumptions made in the PPCS. These changes allow either reduced cost versions of the PPCS plant models or, alternatively, plants with less ambitious technical assumptions at constant cost. The impact of the new results, emerging from the EU DEMO studies, on the role of fusion in the future energy market is described. A new energy economics model is employed to analyse the potential market performance of fusion power in a range of future energy scenarios and this shows that there can be a significant role for fusion in a future energy market.

High-power corrugates waveguide components for mm-wave fusion heating systems

International Nuclear Information System (INIS)

Olstad, R.A.; Doane, J.L.; Moeller, C.P.; O'Neill, R.C.; Di Martino, M.

1996-10-01

Considerable progress has been made over the last year in the U.S., Japan, Russia, and Europe in developing high power long pulse gyrotrons for fusion plasma heating and current drive. These advanced gyrotrons typically operate at a frequency in the range 82 GHz to 170 GHz at nearly megawatt power levels for pulse lengths up to 5 s. To take advantage of these new microwave sources for fusion research, new and improved transmission line components are needed to reliably transmit microwave power to plasmas with minimal losses. Over the last year, General Atomics and collaborating companies (Spinner GmbH in Europe and Toshiba Corporation in Japan) have developed a wide variety of new components which meet the demanding power, pulse length, frequency, and vacuum requirements for effective utilization of the new generation of gyrotrons. These components include low-loss straight corrugated waveguides, miter bends, miter bend polarizers, power monitors, waveguide bellows, de breaks, waveguide switches, dummy loads, and distributed windows. These components have been developed with several different waveguide diameters (32, 64, and 89 mm) and frequency ranges (82 GHz to 170 GHz). This paper describes the design requirements of selected components and their calculated and measured performance characteristics

Thermal energy and bootstrap current in fusion reactor plasmas

International Nuclear Information System (INIS)

Becker, G.

1993-01-01

For DT fusion reactors with prescribed alpha particle heating power P α , plasma volume V and burn temperature i > ∼ 10 keV specific relations for the thermal energy content, bootstrap current, central plasma pressure and other quantities are derived. It is shown that imposing P α and V makes these relations independent of the magnitudes of the density and temperature, i.e. they only depend on P α , V and shape factors or profile parameters. For model density and temperature profiles analytic expressions for these shape factors and for the factor C bs in the bootstrap current formula I bs ∼ C bs (a/R) 1/2 β p I p are given. In the design of next-step devices and fusion reactors, the fusion power is a fixed quantity. Prescription of the alpha particle heating power and plasma volume results in specific relations which can be helpful for interpreting computer simulations and for the design of fusion reactors. (author) 5 refs

Fusion power: the transition from fundamental science to fusion reactor engineering

International Nuclear Information System (INIS)

Post, R.F.

1975-01-01

The historical development of fusion research is outlined. The basics of fusion power along with fuel cost and advantages of fusion are discussed. Some quantitative requirements for fusion power are described. (MOW)

Optimizing MEMS-Based Storage Devices for Mobile Battery-Powered Systems

NARCIS (Netherlands)

Khatib, M.G.; Hartel, Pieter H.

An emerging storage technology, called MEMS-based storage, promises nonvolatile storage devices with ultrahigh density, high rigidity, a small form factor, and low cost. For these reasons, MEMS-based storage devices are suitable for battery-powered mobile systems such as PDAs. For deployment in such

High power density carbonate fuel cell

Energy Technology Data Exchange (ETDEWEB)

Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

1996-12-31

Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

EDITORIAL: Safety aspects of fusion power plants

Science.gov (United States)

Kolbasov, B. N.

2007-07-01

importance for the fusion power plant research programmes. The objective of this Technical Meeting was to examine in an integrated way all the safety aspects anticipated to be relevant to the first fusion power plant prototype expected to become operational by the middle of the century, leading to the first generation of economically viable fusion power plants with attractive S&E features. After screening by guest editors and consideration by referees, 13 (out of 28) papers were accepted for publication. They are devoted to the following safety topics: power plant safety; fusion specific operational safety approaches; test blanket modules; accident analysis; tritium safety and inventories; decommissioning and waste. The paper `Main safety issues at the transition from ITER to fusion power plants' by W. Gulden et al (EU) highlights the differences between ITER and future fusion power plants with magnetic confinement (off-site dose acceptance criteria, consequences of accidents inside and outside the design basis, occupational radiation exposure, and waste management, including recycling and/or final disposal in repositories) on the basis of the most recent European fusion power plant conceptual study. Ongoing S&E studies within the US inertial fusion energy (IFE) community are focusing on two design concepts. These are the high average power laser (HAPL) programme for development of a dry-wall, laser-driven IFE power plant, and the Z-pinch IFE programme for the production of an economically-attractive power plant using high-yield Z-pinch-driven targets. The main safety issues related to these programmes are reviewed in the paper `Status of IFE safety and environmental activities in the US' by S. Reyes et al (USA). The authors propose future directions of research in the IFE S&E area. In the paper `Recent accomplishments and future directions in the US Fusion Safety & Environmental Program' D. Petti et al (USA) state that the US fusion programme has long recognized that the S

Ceramics for fusion devices

International Nuclear Information System (INIS)

Clinard, F.W. Jr.

1984-01-01

Ceramics are required for a number of applications in fusion devices, among the most critical of which are magnetic coil insulators, windows for RF heating systems, and structural uses. Radiation effects dominate consideration of candidate materials, although good pre-irradiation properties are a requisite. Materials and components can be optimized by careful control of chemical and microstructural content, and application of brittle material design and testing techniques. Future directions for research and development should include further extension of the data base in the areas of electrical, structural, and thermal properties; establishment of a fission neutron/fusion neutron correlation including transmutation gas effects; and development of new materials tailored to meet the specific needs of fusion reactors

High-energy density physics at Los Alamos

International Nuclear Information System (INIS)

Byrnes, P.; Younger, S.M.

1993-03-01

This brochure describes the facilities of the Above Ground Experiments II (AGEX II) and the Inertial Confinement Fusion (ICF) programs at Los Alamo. Combined, these programs represent, an unparalleled capability to address important issues in high-energy density physics that are critical to the future defense, energy, and research needs of th e United States. The mission of the AGEX II program at Los Alamos is to provide additional experimental opportunities for the nuclear weapons program. For this purpose we have assembled at Los Alamos the broadest array of high-energy density physics facilities of any laboratory in the world. Inertial confinement fusion seeks to achieve thermonuclear burn on a laboratory scale through the implosion of a small quantity of deuterium and tritium fuel to very high Pressure and temperature.The Los Alamos ICF program is focused on target physics. With the largest scientific computing center in the world, We can perform calculations of unprecedented sophistication and precision. We field experiments at facilities worldwide-including our own Trident and Mercury lasers-to confirm our understanding and to provide the necessary data base to proceed toward the historic goal of controlled fusion in the laboratory. In addition to direct programmatic high-energy density physics is a nc scientific endeavor in itself. The ultrahigh magnetic fields produced in our high explosive pulsed-power generators can be used in awide variety of solid state physics and temperature superconductor studies. The structure and dynamics of planetary atmospheres can be simulated through the compression of gas mixtures

Confinement studies of a high current density RFP in the Extrap T1 Upgrade device

International Nuclear Information System (INIS)

Drake, J.R.; Brzozowski, J.H.; Brunsell, P.; Hellblom, G.; Karlsson, P.; Mazur, S.; Nordlund, P.; Welander, A.; Zastrow, K.D.

1992-01-01

Confinement studies have been carried out on the Extrap T1 device operated in the reversed field pinch (RFP) mode. Extrap T1 is a small device with a major radius of R=0.5 m and a high aspect ratio, R/a=8.9. For these experiments, the device has been operated with a resistive shell with measured, toroidally-averaged flux penetration times of τ sv = 500μs (vertical) and τ sR =300μs (radial). The pulse lengths are about 600 μs, which is slightly longer than the shell penetration time. The purpose of these experiments is to study energy confinement in a high aspect-ratio, high current-density RFP device with a resistive shell. The device can be operated with high current densities which exceed 20 MAm -2 on axis. For these discharges, the average electron density is relatively high, ≅ 1x10 20 m -3 . Therefore, although the average current density exceeds 5 MAm -2 , the important parameter / ≅ I/N is maintained less than 1x10 -13 Am, where N is the line density. The plasma diagnostics for the device include a single chord CO 2 laser interferometer ( ), single point Thomson scattering (T e , n o ), VUV and visible spectroscopy (T e , Z eff ) surface barrier diodes for soft X-ray measurements (T e ), bolometry (P rad ), surface probes (Γ p ,T i ) and comprehensive magnetic diagnostics for both equilibrium and magnetic fluctuation studies. (author) 5 refs., 1 fig., 1 tab

Magnetic cusp and electric nested- or single-well configurations for high density antihydrogen and fusion nonneutral plasma applications

International Nuclear Information System (INIS)

Ordonez, C. A.

1999-01-01

Malmberg-Penning traps have had limited uses for applications that require high density nonneutral plasma confinement. For such traps, the density is severely limited because a magnetic field is used to provide a radially inward force to balance both self-electric and centrifugal radially outward forces. A possible way to confine higher density nonneutral plasmas is to use a magnetic cusp configuration. An annular nonneutral plasma would be confined in the radial magnetic field of a magnetic cusp such that radial confinement is provided by an externally produced electric potential well while axial confinement is provided by the magnetic field. In addition, a radial electric potential profile having a nested-well configuration can be used to simultaneously confine two oppositely signed plasma species (e.g., positrons and antiprotons) that overlap. In the work reported, various aspects of using magnetic cusp configurations and electric nested-well configurations are considered. Plasma confinement with these configurations may be useful for obtaining fast antihydrogen recombination and trapping rates and for achieving practical fusion power production

Magnetic Cusp and Electric Nested- or Single-Well Configurations for High Density Antihydrogen and Fusion Nonneutral Plasma Applications

International Nuclear Information System (INIS)

C.A. Ordonez

1999-01-01

Malmberg-Penning traps have had limited uses for applications that require high density nonneutral plasma confinement. For such traps, the density is severely limited because a magnetic field is used to provide a radially inward force to balance both self-electric and centrifugal radially outward forces. A possible way to confine higher density nonneutral plasmas is to use a magnetic cusp configuration. An annular nonneutral plasma would be confined in the radial magnetic field of a magnetic cusp such that radial confinement is provided by an externally produced electric potential well while axial confinement is provided by the magnetic field. In addition, a radial electric potential profile having a nested-well configuration can be used to simultaneously confine two oppositely signed plasma species (e.g., positrons and antiprotons) that overlap. In the work reported, various aspects of using magnetic cusp configurations and electric nested-well configurations are considered. Plasma confinement with these configurations may be useful for obtaining fast antihydrogen recombination and trapping rates and for achieving practical fusion power production

Construction of a dog training device with high frequency and high power pulses

International Nuclear Information System (INIS)

Viaud Trejos, Rafael Alfonso

2013-01-01

An electronic device is built to produce high frequency and high power sound. The device is used in training and control of dogs. Commercial ultrasonic devices used for dog training are analyzed. The best strategies and components of the design are determined from an electronic device to produce sounds in frequency from 15kHz to 50Khz. Effectiveness tests are performed to establish the adequate design of the ultrasonic electronic device. The test results are analyzed to find opportunities of improvement in the design or construction of the device [es

OVERVIEW OF NEUTRON MEASUREMENTS IN JET FUSION DEVICE.

Science.gov (United States)

Batistoni, P; Villari, R; Obryk, B; Packer, L W; Stamatelatos, I E; Popovichev, S; Colangeli, A; Colling, B; Fonnesu, N; Loreti, S; Klix, A; Klosowski, M; Malik, K; Naish, J; Pillon, M; Vasilopoulou, T; De Felice, P; Pimpinella, M; Quintieri, L

2017-10-05

The design and operation of ITER experimental fusion reactor requires the development of neutron measurement techniques and numerical tools to derive the fusion power and the radiation field in the device and in the surrounding areas. Nuclear analyses provide essential input to the conceptual design, optimisation, engineering and safety case in ITER and power plant studies. The required radiation transport calculations are extremely challenging because of the large physical extent of the reactor plant, the complexity of the geometry, and the combination of deep penetration and streaming paths. This article reports the experimental activities which are carried-out at JET to validate the neutronics measurements methods and numerical tools used in ITER and power plant design. A new deuterium-tritium campaign is proposed in 2019 at JET: the unique 14 MeV neutron yields produced will be exploited as much as possible to validate measurement techniques, codes, procedures and data currently used in ITER design thus reducing the related uncertainties and the associated risks in the machine operation. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The effects of electrode cleaning and conditioning on the performance of high-energy, pulsed-power devices

Energy Technology Data Exchange (ETDEWEB)

Cuneo, M.E.

1998-09-01

High-energy pulsed-power devices routinely access field strengths above those at which broad-area, cathode-initiated, high-voltage vacuum-breakdown occur (> 1e7--3e7 V/m). Examples include magnetically-insulated-transmission-lines and current convolutes, high-current-density electron and ion diodes, high-power microwave devices, and cavities and other structures for electrostatic and RF accelerators. Energy deposited in anode surfaces may exceed anode plasma thermal-desorption creation thresholds on the time-scale of the pulse. Stimulated desorption by electron or photon bombardment can also lead to plasma formation on electrode or insulator surfaces. Device performance is limited above these thresholds, particularly in pulse length and energy, by the formation and expansion of plasmas formed primarily from electrode contaminants. In-situ conditioning techniques to modify and eliminate the contaminants through multiple high-voltage pulses, low base pressures, RF discharge cleaning, heating, surface coatings, and ion- and electron-beam surface treatment allow access to new regimes of performance through control of plasma formation and modification of the plasma properties. Experimental and theoretical progress from a variety of devices and small scale experiments with a variety of treatment methods will be reviewed and recommendations given for future work.

High-throughput deterministic single-cell encapsulation and droplet pairing, fusion, and shrinkage in a single microfluidic device

NARCIS (Netherlands)

Schoeman, R.M.; Kemna, Evelien; Wolbers, F.; van den Berg, Albert

In this article, we present a microfluidic device capable of successive high-yield single-cell encapsulation in droplets, with additional droplet pairing, fusion, and shrinkage. Deterministic single-cell encapsulation is realized using Dean-coupled inertial ordering of cells in a Yin-Yang-shaped

Progress in pulsed power fusion

Energy Technology Data Exchange (ETDEWEB)

Quintenz, J P; Adams, R G; Bailey, J E [Sandia Labs., Albuquerque, NM (United States); and others

1997-12-31

Pulsed power offers an efficient, high energy, economical source of x-rays for inertial confinement fusion (ICF) research. Two main approaches to ICF driven with pulsed power accelerators are pursued: intense light ion beams and z-pinches. Recent progress in each approach and plans for future development is described. (author). 2 figs., 10 refs.

Progress in pulsed power fusion

International Nuclear Information System (INIS)

Quintenz, J.P.; Adams, R.G.; Bailey, J.E.

1996-01-01

Pulsed power offers an efficient, high energy, economical source of x-rays for inertial confinement fusion (ICF) research. Two main approaches to ICF driven with pulsed power accelerators are pursued: intense light ion beams and z-pinches. Recent progress in each approach and plans for future development is described. (author). 2 figs., 10 refs

Physics and technology of large plasma focus devices

International Nuclear Information System (INIS)

Herold, H.

1990-01-01

This paper reports on the plasma focus (PF) which produces a high temperature (0,5 to 1 keV), high density (5 · 10 18 cm -3 ), short living (up to 500 ns) fusion plasma in a very simple and cheap device. In the focus plasma, fusion processes take place with an energy efficiency which is not surpassed even by large Tokamak or Inertial Confinement Fusion devices. But this fusion efficiency and the high fusion neutron yield are not the only impetus to PF research. Due to the high energy density in the focus plasma (j ≥ 10 6 A/cm 2 exclamation point), many very interesting, mostly nonlinear phenomena take place which led to high intensity electron, ion and radiation emission. Micro- and macro instabilities, turbulence and selforganization processes develop. Most of these phenomena are not or only poorly understood

High energy density capacitors fabricated by thin film technology

International Nuclear Information System (INIS)

Barbee, T W; Johnson, G W; Wagner, A V.

1999-01-01

Low energy density in conventional capacitors severely limits efforts to miniaturize power electronics and imposes design limitations on electronics in general. We have successfully applied physical vapor deposition technology to greatly increase capacitor energy density. The high dielectric breakdown strength we have achieved in alumina thin films allows high energy density to be achieved with this moderately low dielectric constant material. The small temperature dependence of the dielectric constant, and the high reliability, high resistivity, and low dielectric loss of Al 2 O 3 , make it even more appealing. We have constructed single dielectric layer thin film capacitors and shown that they can be stacked to form multilayered structures with no loss in yield for a given capacitance. Control of film growth morphology is critical for achieving the smooth, high quality interfaces between metal and dielectric necessary for device operation at high electric fields. Most importantly, high rate deposition with extremely low particle generation is essential for achieving high energy storage at a reasonable cost. This has been achieved by reactive magnetron sputtering in which the reaction to form the dielectric oxide has been confined to the deposition surface. By this technique we have achieved a yield of over 50% for 1 cm 2 devices with an energy density of 14 J per cubic centimeter of Al 2 O 3 dielectric material in 1.2 kV, 4 nF devices. By further reducing defect density and increasing the dielectric constant of the material, we will be able to increase capacitance and construct high energy density devices to meet the requirements of applications in power electronics

Simulation, measurement, and emulation of photovoltaic modules using high frequency and high power density power electronic circuits

Science.gov (United States)

Erkaya, Yunus

system variables so that any PV module can be emulated as the design requires. A non-synchronous buck converter is proposed for the emulation of a single, high-power PV module using traditional silicon devices. With the proof-of-concept working and improvements in efficiency, power density and steady-state errors made, dynamic tests were performed using an inverter connected to the PV emulator. In order to improve the dynamic characteristics, a synchronous buck converter topology is proposed along with the use of advanced GaNFET devices which resulted in very high power efficiency and improved dynamic response characteristics when emulating PV modules.

Final Technical Report for "Nuclear Technologies for Near Term Fusion Devices"

Energy Technology Data Exchange (ETDEWEB)

Wilson, Paul P.H. [Univ. of Wisconsin, Madison, WI (United States); Sawan, Mohamed E. [Univ. of Wisconsin, Madison, WI (United States); Davis, Andrew [Univ. of Wisconsin, Madison, WI (United States); Bohm, Tim D. [Univ. of Wisconsin, Madison, WI (United States)

2017-09-05

Over approximately 18 years, this project evolved to focus on a number of related topics, all tied to the nuclear analysis of fusion energy systems. For the earliest years, the University of Wisconsin (UW)’s effort was in support of the Advanced Power Extraction (APEX) study to investigate high power density first wall and blanket systems. A variety of design concepts were studied before this study gave way to a design effort for a US Test Blanket Module (TBM) to be installed in ITER. Simultaneous to this TBM project, nuclear analysis supported the conceptual design of a number of fusion nuclear science facilities that might fill a role in the path to fusion energy. Beginning in approximately 2005, this project added a component focused on the development of novel radiation transport software capability in support of the above nuclear analysis needs. Specifically, a clear need was identified to support neutron and photon transport on the complex geometries associated with Computer-Aided Design (CAD). Following the initial development of the Direct Accelerated Geoemtry Monte Carlo (DAGMC) capability, additional features were added, including unstructured mesh tallies and multi-physics analysis such as the Rigorous 2-Step (R2S) methodology for Shutdown Dose Rate (SDR) prediction. Throughout the project, there were also smaller tasks in support of the fusion materials community and for the testing of changes to the nuclear data that is fundamental to this kind of nuclear analysis.

Progress of research and development of nuclear fusion and development of large nuclear fusion device technology

International Nuclear Information System (INIS)

1994-01-01

In the last several years, the results of tokamak experiments were conspicuous, and the progress of plasma confinement performance, transport mechanism, divertors and impurities, helium transport and exhaust, electric current drive, magnetic field ripple effect and high speed particle transport and DT experiment are reported. The other confinement methods than tokamak, the related theories and reactor technology are described. The conceptual design of ITER was carried out by the cooperation of Japan, USA, EC and the former USSR. The projects of developing nuclear fusion in various countries, the design and the required research and development of ITER, the reconstruction and the required research and development of JT-60, JET and TFTR, the design and the required research and development of large helical device, the state of research and development of laser nuclear fusion and inversion magnetic field pinch nuclear fusion, the activities and roles of industrial circles in large nuclear fusion device technology, and the long term perspective of the technical development of nuclear fusion are described. (K.I.)

Proceedings of US/Japan workshop, Q219 on high heat flux components and plasma surface interactions for next fusion devices

Energy Technology Data Exchange (ETDEWEB)

Ulrickson, M.A.; Stevens, P.L.; Hino, T.; Hirohata, Y. [eds.

1996-12-01

This report contains the viewgraphs from the proceedings of US/Japan Workshop on High Heat Flux Components and Plasma Surface Interactions for Next Fusion Devices. Some of the general topics covered by this report are: PFC/PSI in tokamak and helical devices; development of high heat flux components; PSIS and plasma facing materials;tritium; and material damage.

Proceedings of US/Japan workshop, Q219 on high heat flux components and plasma surface interactions for next fusion devices

International Nuclear Information System (INIS)

Ulrickson, M.A.; Stevens, P.L.; Hino, T.; Hirohata, Y.

1996-12-01

This report contains the viewgraphs from the proceedings of US/Japan Workshop on High Heat Flux Components and Plasma Surface Interactions for Next Fusion Devices. Some of the general topics covered by this report are: PFC/PSI in tokamak and helical devices; development of high heat flux components; PSIS and plasma facing materials;tritium; and material damage

Controlled thermonuclear fusion reactors

International Nuclear Information System (INIS)

Walstrom, P.L.

1976-01-01

Controlled production of energy by fusion of light nuclei has been the goal of a large portion of the physics community since the 1950's. In order for a fusion reaction to take place, the fuel must be heated to a temperature of 100 million degrees Celsius. At this temperature, matter can exist only in the form of an almost fully ionized plasma. In order for the reaction to produce net power, the product of the density and energy confinement time must exceed a minimum value of 10 20 sec m -3 , the so-called Lawson criterion. Basically, two approaches are being taken to meet this criterion: inertial confinement and magnetic confinement. Inertial confinement is the basis of the laser fusion approach; a fuel pellet is imploded by intense laser beams from all sides and ignites. Magnetic confinement devices, which exist in a variety of geometries, rely upon electromagnetic forces on the charged particles of the plasma to keep the hot plasma from expanding. Of these devices, the most encouraging results have been achieved with a class of devices known as tokamaks. Recent successes with these devices have given plasma physicists confidence that scientific feasibility will be demonstrated in the next generation of tokamaks; however, an even larger effort will be required to make fusion power commercially feasible. As a result, emphasis in the controlled thermonuclear research program is beginning to shift from plasma physics to a new branch of nuclear engineering which can be called fusion engineering, in which instrumentation and control engineers will play a major role. Among the new problem areas they will deal with are plasma diagnostics and superconducting coil instrumentation

Spatial and temporal instabilities in high voltage power devices

Energy Technology Data Exchange (ETDEWEB)

Milady, Saeed

2010-01-29

Dynamic avalanche can occur during the turn-off process of high voltage bipolar devices, e.g. IGBTs and p{sup +}n{sup -}n{sup +} power diodes, that may result in spatial instabilities of the homogeneous current density distribution across the device and the formation of current filaments. Filaments may cause the destruction of the device, mainly because of the high local temperatures. The first part of this work is dedicated to the current filament behavior. The positive feedback mechanisms caused by the transient current flow through the gate capacitance of an IGBT operating under short circuit conditions may result in oscillations and temporal instabilities of the IGBT current. The oscillations may cause electromagnetic interference (EMI). Furthermore, the positive feedback mechanism may accelerate the over-heating of the device and result in a thermal run-away. This is the subject of the second part of this work. In the first part of this work using the device simulation results of power diodes the underlying physical mechanisms of the filament dynamic is investigated. Simulation results of diode structures with evenly distributed doping inhomogeneities show that, the filament motion gets smoother as the distance between the inhomogeneities decreases. Hopping to faraway inhomogeneities turns into the hopping to neighboring ones and finally a smooth motion. In homogeneous structures the slow inhibitory effect of the electron-hole plasma extraction and the fast activation, due to hole current flowing along the filament, result in a smooth filament motion. An analytical model for the filament velocity under isothermal conditions is presented that can reproduce the simulation data satisfactorily. The influence of the boundary conditions on the filament behavior is discussed. The positive beveled edge termination prohibits a long stay of the filament at the edge reducing the risk of filament pinning. Self-heating effects may turn the initially electrically triggered

Structural materials challenges for fusion power systems

International Nuclear Information System (INIS)

Kurtz, Richard J.

2009-01-01

Full text: Structural materials in a fusion power system must function in an extraordinarily demanding environment that includes various combinations of high temperatures, reactive chemicals, time-dependent thermal and mechanical stresses, and intense damaging radiation. The fusion neutron environment produces displacement damage equivalent to displacing every atom in the material about 150 times during its expected service life, and changes in chemical composition by transmutation reactions, which includes creation of reactive and insoluble gases. Fundamental materials challenges that must be resolved to effectively harness fusion power include (1) understanding the relationships between material strength, ductility and resistance to cracking, (2) development of materials with extraordinary phase stability, high-temperature strength and resistance to radiation damage, (3) establishment of the means to control corrosion of materials exposed to aggressive environments, (4) development of technologies for large-scale fabrication and joining, and (5) design of structural materials that provide for an economically attractive fusion power system while simultaneously achieving safety and environmental acceptability goals. The most effective approach to solve these challenges is a science-based effort that couples development of physics-based, predictive models of materials behavior with key experiments to validate the models. The U.S. Fusion Materials Sciences program is engaged in an integrated effort of theory, modeling and experiments to develop structural materials that will enable fusion to reach its safety, environmental and economic competitiveness goals. In this presentation, an overview of recent progress on reduced activation ferritic/martensitic steels, nanocomposited ferritic alloys, and silicon carbide fiber reinforced composites for fusion applications will be given

Flexible GaN for High Performance, Strainable Radio Frequency Devices (Postprint)

Science.gov (United States)

2017-11-02

wireless systems where consumers will benefit significantly from the high power densities achievable in GaN devices.[8] Further complicating the...future strainable and conformal devices for transmission of radio-frequency (RF) signals over large distances for more efficient wireless communication... power density of traditional RF amplifier materials at different frequencies and wireless generation bands, as well as an image of the flexible GaN

Summary of the 16th IAEA Technical Meeting on 'Research using Small Fusion Devices'

International Nuclear Information System (INIS)

Gribkov, V.; Oost, G. van; Malaquias, A.; Herrera, J.

2006-01-01

Common research topics that are being studied in small, medium and large devices such as H-mode like or improved confinement, turbulence and transport are reported. These included modelling and diagnostic developments for edge and core, to characterize plasma density, temperature, electric potential, plasma flows, turbulence scale, etc. Innovative diagnostic methods were designed and implemented which could be used to develop experiments in small devices (in some cases not possible in large devices due to higher power deposition) to allow a better understanding of plasma edge and core properties. Reports are given addressing research in linear devices that can be used to study particular plasma physics topics relevant for other magnetic confinement devices such as the radial transport and the modelling of self-organized plasma jets involved in spheromak-like plasma formation. Some aspects of the work presented are of interest to the astrophysics community since they are believed to shed light on the basis of the physics of stellar jets. On the dense magnetized plasmas (DMP) topic, the present status of research, operation of new devices, plasma dynamics modelling and diagnostic developments is reported. The main devices presented belong to the class of Z-pinches, mostly plasma foci, and several papers were presented under this topic. The physics of DMP is important both for the main-stream fusion investigations as well as for providing the basis for elaboration of new concepts. New high-current technology introduced in the DMP devices design and construction make these devices nowadays more reliably fitted to various applications and give the possibility to widen the energy range used by them in both directions-to the multi-MJ level facilities and down to miniature plasma focus devices with energy of just a few J. (conference report)

Power Requirements Determined for High-Power-Density Electric Motors for Electric Aircraft Propulsion

Science.gov (United States)

Johnson, Dexter; Brown, Gerald V.

2005-01-01

Future advanced aircraft fueled by hydrogen are being developed to use electric drive systems instead of gas turbine engines for propulsion. Current conventional electric motor power densities cannot match those of today s gas turbine aircraft engines. However, if significant technological advances could be made in high-power-density motor development, the benefits of an electric propulsion system, such as the reduction of harmful emissions, could be realized.

Pulsed power for fusion

International Nuclear Information System (INIS)

Martin, T.H.

1976-01-01

A review which traces the development of high power pulsed accelerators from the original inception at the Atomic Weapons Research Establishment, Aldermaston, England, for Bremsstrahlung output, through the low impedance accelerators, to the double-sided accelerators for fusion will be given. Proto II is presently being assembled at Sandia and preliminary testing on the Marx has been completed. Examples of various techniques will be shown from Sandia accelerators. Requirements for accelerators capable of achieving fusion levels will be developed and problem areas outlined. The diode insulator flashover problem presently limits the maximum current available from the accelerators

Fusion power production from TFTR plasmas fueled with deuterium and tritium

International Nuclear Information System (INIS)

Strachan, J.D.; Adler, H.; Alling, P.

1994-03-01

Peak fusion power production of 6.2 ± 0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total power of 29.5 MW. These plasmas have an inferred central fusion alpha particle density of 1.2 x 10 17 m -3 without the appearance of either disruptive MHD events or detectable changes in Alfven wave activity. The measured loss rate of energetic alpha particles agreed with the approximately 5% losses expected from alpha particles which are born on unconfined orbits

Simulations of alpha parameters in a TFTR DT supershot with high fusion power

International Nuclear Information System (INIS)

Budny, R.V.; Bell, M.G.; Janos, A.C.

1995-07-01

A TFTR supershot with a plasma current of 2.5 MA, neutral beam heating power of 33.7 MW, and a peak DT fusion power of 7.5 MW is studied using the TRANSP plasma analysis code. Simulations of alpha parameters such as the alpha heating, pressure, and distributions in energy and v parallel /v are given. The effects of toroidal ripple and mixing of the fast alpha particles during the sawteeth observed after the neutral beam injection phase are modeled. The distributions of alpha particles on the outer midplane are peaked near forward and backward v parallel /v. Ripple losses deplete the distributions in the vicinity of v parallel /v ∼-0.4. Sawtooth mixing of fast alpha particles is computed to reduce their central density and broaden their width in energy

Block Ignition Inertial Confinement Fusion (ICF) with Condensed Matter Cluster Type Targets for p-B11 Powered Space Propulsion

International Nuclear Information System (INIS)

Miley, George H.; Hora, H.; Badziak, J.; Wolowski, J.; Sheng Zhengming; Zhang Jie; Osman, F.; Zhang Weiyan; Tuhe Xia

2009-01-01

The use of laser-driven Inertial Confinement Fusion (ICF) for space propulsion has been the subject of several earlier conceptual design studies, (see: Orth, 1998; and other references therein). However, these studies were based on older ICF technology using either 'direct' or 'in-direct x-ray driven' type target irradiation. Important new directions have opened for laser ICF in recent years following the development of 'chirped' lasers capable of ultra short pulses with powers of TW up to few PW which leads to the concept of 'fast ignition (FI)' to achieve higher energy gains from target implosions. In a recent publication the authors showed that use of a modified type of FI, termed 'block ignition' (Miley et al., 2008), could meet many of the requirements anticipated (but not then available) by the designs of the Vehicle for Interplanetary Space Transport Applications (VISTA) ICF fusion propulsion ship (Orth, 2008) for deep space missions. Subsequently the first author devised and presented concepts for imbedding high density condensed matter 'clusters' of deuterium into the target to obtain ultra high local fusion reaction rates (Miley, 2008). Such rates are possible due to the high density of the clusters (over an order of magnitude above cryogenic deuterium). Once compressed by the implosion, the yet higher density gives an ultra high reaction rate over the cluster volume since the fusion rate is proportional to the square of the fuel density. Most recently, a new discovery discussed here indicates that the target matrix could be composed of B 11 with proton clusters imbedded. This then makes p-B 11 fusion practical, assuming all of the physics issues such as stability of the clusters during compression are resolved. Indeed, p-B 11 power is ideal for fusion propulsion since it has a minimum of unwanted side products while giving most of the reaction energy to energetic alpha particles which can be directed into an exhaust (propulsion) nozzle. Power plants

Block Ignition Inertial Confinement Fusion (ICF) with Condensed Matter Cluster Type Targets for p-B11 Powered Space Propulsion

Science.gov (United States)

Miley, George H.; Hora, H.; Badziak, J.; Wolowski, J.; Sheng, Zheng-Ming; Zhang, Jie; Osman, F.; Zhang, Weiyan; tu He, Xia

2009-03-01

The use of laser-driven Inertial Confinement Fusion (ICF) for space propulsion has been the subject of several earlier conceptual design studies, (see: Orth, 1998; and other references therein). However, these studies were based on older ICF technology using either "direct "or "in-direct x-ray driven" type target irradiation. Important new directions have opened for laser ICF in recent years following the development of "chirped" lasers capable of ultra short pulses with powers of TW up to few PW which leads to the concept of "fast ignition (FI)" to achieve higher energy gains from target implosions. In a recent publication the authors showed that use of a modified type of FI, termed "block ignition" (Miley et al., 2008), could meet many of the requirements anticipated (but not then available) by the designs of the Vehicle for Interplanetary Space Transport Applications (VISTA) ICF fusion propulsion ship (Orth, 2008) for deep space missions. Subsequently the first author devised and presented concepts for imbedding high density condensed matter "clusters" of deuterium into the target to obtain ultra high local fusion reaction rates (Miley, 2008). Such rates are possible due to the high density of the clusters (over an order of magnitude above cryogenic deuterium). Once compressed by the implosion, the yet higher density gives an ultra high reaction rate over the cluster volume since the fusion rate is proportional to the square of the fuel density. Most recently, a new discovery discussed here indicates that the target matrix could be composed of B11 with proton clusters imbedded. This then makes p-B11 fusion practical, assuming all of the physics issues such as stability of the clusters during compression are resolved. Indeed, p-B11 power is ideal for fusion propulsion since it has a minimum of unwanted side products while giving most of the reaction energy to energetic alpha particles which can be directed into an exhaust (propulsion) nozzle. Power plants using p

Which are the competitors for a fusion power plant?

International Nuclear Information System (INIS)

Miller, Ronald L.

2000-01-01

The (future) competitive position of central-station fusion power will depend on the resolution of several broad public-policy issues, including the provision of adequate electrical energy to a growing world population and the interaction of economic and environmental considerations meeting evolving standards of public acceptance and regulatory compliance. Candidate baseload central-station power plants, fusion or other, will be expected to contend for preferential market penetration against an evolving set of performance indicators or metrics (e.g. cost of electricity) reflecting societal 'customer preferences' for abundant, affordable, safe, reliable, and environmentally benign sources. This competition is enhanced by transitions to price-deregulated regimes, overlaid by nuclear uncertainites and evolution beyond carbon-based fuels toward more renewables in the energy mix. From these top-level considerations, quantifiable attributes, including plant size (output), system power density, surface heat flux, recirculating power fraction, power-conversion efficiency, waste streams, and forced- and planned-outage rates emerge

Mirror Fusion Test Facility: an intermediate device to a mirror fusion reactor

International Nuclear Information System (INIS)

Karpenko, V.N.

1983-01-01

The Mirror Fusion Test Facility (MFTF-B) now under construction at Lawrence Livermore National Laboratory represents more than an order-of-magnitude step from earlier magnetic-mirror experiments toward a future mirror fusion reactor. In fact, when the device begins operating in 1986, the Lawson criteria of ntau = 10 14 cm -3 .s will almost be achieved for D-T equivalent operation, thus signifying scientific breakeven. Major steps have been taken to develop MFTF-B technologies for tandem mirrors. Steady-state, high-field, superconducting magnets at reactor-revelant scales are used in the machine. The 30-s beam pulses, ECRH, and ICRH will also introduce steady-state technologies in those systems

Macron Formed Liner Compression as a Practical Method for Enabling Magneto-Inertial Fusion

Energy Technology Data Exchange (ETDEWEB)

Slough, John

2011-12-10

The entry of fusion as a viable, competitive source of power has been stymied by the challenge of finding an economical way to provide for the confinement and heating of the plasma fuel. The main impediment for current nuclear fusion concepts is the complexity and large mass associated with the confinement systems. To take advantage of the smaller scale, higher density regime of magnetic fusion, an efficient method for achieving the compressional heating required to reach fusion gain conditions must be found. The very compact, high energy density plasmoid commonly referred to as a Field Reversed Configuration (FRC) provides for an ideal target for this purpose. To make fusion with the FRC practical, an efficient method for repetitively compressing the FRC to fusion gain conditions is required. A novel approach to be explored in this endeavor is to remotely launch a converging array of small macro-particles (macrons) that merge and form a more massive liner inside the reactor which then radially compresses and heats the FRC plasmoid to fusion conditions. The closed magnetic field in the target FRC plasmoid suppresses the thermal transport to the confining liner significantly lowering the imploding power needed to compress the target. With the momentum flux being delivered by an assemblage of low mass, but high velocity macrons, many of the difficulties encountered with the liner implosion power technology are eliminated. The undertaking to be described in this proposal is to evaluate the feasibility achieving fusion conditions from this simple and low cost approach to fusion. During phase I the design and testing of the key components for the creation of the macron formed liner have been successfully carried out. Detailed numerical calculations of the merging, formation and radial implosion of the Macron Formed Liner (MFL) were also performed. The phase II effort will focus on an experimental demonstration of the macron launcher at full power, and the demonstration

Poloidal variations in toroidal fusion reactor wall power loadings

International Nuclear Information System (INIS)

Carroll, M.C.; Miley, G.H.

1985-01-01

A geometric formulation is developed by the authors for determining poloidal variations in bremmstrahlung, cyclotron radiation, and neutron wall power loadings in toroidal fusion devices. Assuming toroidal symmetry and utilizing a numerical model which partitions the plasma into small cells, it was generally found that power loadings are highest on the outer surface of the torus, although variations are not as large as some have predicted. Results are presented for various plasma power generation configurations, plasma volume fractions, and toroidal aspect ratios, and include plasma and wall blockage effects

A microfabricated low cost enzyme-free glucose fuel cell for powering low-power implantable devices

Science.gov (United States)

Oncescu, Vlad; Erickson, David

In the past decade the scientific community has showed considerable interest in the development of implantable medical devices such as muscle stimulators, neuroprosthetic devices, and biosensors. Those devices have low power requirements and can potentially be operated through fuel cells using reactants present in the body such as glucose and oxygen instead of non-rechargeable lithium batteries. In this paper, we present a thin, enzyme-free fuel cell with high current density and good stability at a current density of 10 μA cm -2. A non-enzymatic approach is preferred because of higher long term stability. The fuel cell uses a stacked electrode design in order to achieve glucose and oxygen separation. An important characteristic of the fuel cell is that it has no membrane separating the electrodes, which results in low ohmic losses and small fuel cell volume. In addition, it uses a porous carbon paper support for the anodic catalyst layer which reduces the amount of platinum or other noble metal catalysts required for fabricating high surface area electrodes with good reactivity. The peak power output of the fuel cell is approximately 2 μW cm -2 and has a sustainable power density of 1.5 μW cm -2 at 10 μA cm -2. An analysis on the effects of electrode thickness and inter electrode gap on the maximum power output of the fuel cell is also performed.

Ohmic heating coil power supply using thyristor circuit breaker in a thermonuclear fusion device

International Nuclear Information System (INIS)

Tani, Keiji; Shimada, Ryuichi; Tamura, Sanae; Yabuno, Kohei; Koseki, Shoichiro.

1982-01-01

In a large scale Tokamak thermonuclear fusion device such as the critical plasma testing facility (JT60) presently under construction, mechanical breakers such as vacuum and air breakers are mostly used for interrupting DC heavy current which is supplied to the ohmic heating coils of inductive energy accumulation method. The practical use of the DC breakers employing thyristors has just been started because the history of thyristor development is short and thristors are still expensive, in spite of the advantages. In this paper, the circuit is investigated in which the excellent high speed controllability of thyristors is fully utilized, while the economy is taken into accout, and the experiment carried out with a unit model is described. It was found that a thyristor switch, which was constructed by connecting the high speed thyristors of peak off-state voltage rating 2,000 V and mean current rating 500 A in direct parallel, was able to interrupt 12.7 kA current in the power supply circuit of ohmic heating coils developed this time. In addition, the switch configuration was able to be greatly simplified. When the multistage raising of plasma current is required, the raise can be performed with a single thyristor breaker because it can make high speed control. Therefore, the capacity of the breaker can be doubly and drastically reduced. Also, if current unbalance might occur between thyristor switch units, it gives no problem since the time of reverse voltage after current interruption dispersed smaller as current increased. (Wakatsuki, Y.)

The NIF: An international high energy density science and inertial fusion user facility

Directory of Open Access Journals (Sweden)

Moses E.I.

2013-11-01

Full Text Available The National Ignition Facility (NIF, a 1.8-MJ/500-TW Nd:Glass laser facility designed to study inertial confinement fusion (ICF and high-energy-density science (HEDS, is operational at Lawrence Livermore National Laboratory (LLNL. A primary goal of NIF is to create the conditions necessary to demonstrate laboratory-scale thermonuclear ignition and burn. NIF experiments in support of indirect-drive ignition began late in FY2009 as part of the National Ignition Campaign (NIC, an international effort to achieve fusion ignition in the laboratory. To date, all of the capabilities to conduct implosion experiments are in place with the goal of demonstrating ignition and developing a predictable fusion experimental platform in 2012. The results from experiments completed are encouraging for the near-term achievement of ignition. Capsule implosion experiments at energies up to 1.6 MJ have demonstrated laser energetics, radiation temperatures, and symmetry control that scale to ignition conditions. Of particular importance is the demonstration of peak hohlraum temperatures near 300 eV with overall backscatter less than 15%. Important national security and basic science experiments have also been conducted on NIF. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of laser-driven Inertial Fusion Energy (IFE. This paper will describe the results achieved so far on the path toward ignition, the beginning of fundamental science experiments and the plans to transition NIF to an international user facility providing access to HEDS and fusion energy researchers around the world.

The NIF: An international high energy density science and inertial fusion user facility

Science.gov (United States)

Moses, E. I.; Storm, E.

2013-11-01

The National Ignition Facility (NIF), a 1.8-MJ/500-TW Nd:Glass laser facility designed to study inertial confinement fusion (ICF) and high-energy-density science (HEDS), is operational at Lawrence Livermore National Laboratory (LLNL). A primary goal of NIF is to create the conditions necessary to demonstrate laboratory-scale thermonuclear ignition and burn. NIF experiments in support of indirect-drive ignition began late in FY2009 as part of the National Ignition Campaign (NIC), an international effort to achieve fusion ignition in the laboratory. To date, all of the capabilities to conduct implosion experiments are in place with the goal of demonstrating ignition and developing a predictable fusion experimental platform in 2012. The results from experiments completed are encouraging for the near-term achievement of ignition. Capsule implosion experiments at energies up to 1.6 MJ have demonstrated laser energetics, radiation temperatures, and symmetry control that scale to ignition conditions. Of particular importance is the demonstration of peak hohlraum temperatures near 300 eV with overall backscatter less than 15%. Important national security and basic science experiments have also been conducted on NIF. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of laser-driven Inertial Fusion Energy (IFE). This paper will describe the results achieved so far on the path toward ignition, the beginning of fundamental science experiments and the plans to transition NIF to an international user facility providing access to HEDS and fusion energy researchers around the world.

Bridge between fusion plasma and plasma processing

International Nuclear Information System (INIS)

Ohno, Noriyasu; Takamura, Shuichi

2008-01-01

In the present review, relationship between fusion plasma and processing plasma is discussed. From boundary-plasma studies in fusion devices new applications such as high-density plasma sources, erosion of graphite in a hydrogen plasma, formation of helium bubbles in high-melting-point metals and the use of toroidal plasmas for plasma processing are emerging. The authors would like to discuss a possibility of knowledge transfer from fusion plasmas to processing plasmas. (T. Ikehata)

The European Fusion Energy Research Programme towards the realization of a fusion demonstration reactor

International Nuclear Information System (INIS)

Gasparotto, M.; Laesser, R.

2006-01-01

Since its inception, the European Fusion Programme has been orientated towards the establishment of the knowledge base needed for the definition of a reactor to be used for power production. Its ultimate goal is then to demonstrate the scientific and the technological feasibility of fusion power while incorporating the assessment of the safety, environmental, social and economic features of this type of energy source. At present, the JET device, the largest tokamak in the world, and the other medium-sized experimental machines are contributing essentially to the basic scientific phase of this development path. Their successful operation greatly contributed to support the design basis of ITER, the next step in fusion, which will aim to demonstrate the scientific and technical feasibility of fusion power production by achieving extended D-T burning plasma operation. Following ITER, the conception and construction of the DEMO device is planned. DEMO will be a demonstration power plant which will be the first fusion device to generate a significant amount of electrical power from fusion. This paper describes the status of fusion research and the European strategy for achievement of the ultimate goal of construction of a prototype reactor. (author)

All 2D materials as electrodes for high power hybrid energy storage applications

Science.gov (United States)

Kato, Keiko; Sayed, Farheen N.; Babu, Ganguli; Ajayan, Pulickel M.

2018-04-01

Achieving both high energy and power densities from energy storage devices is a core strategy to meet the increasing demands of high performance portable electronics and electric transportation systems. Li-ion capacitor is a promising hybrid technology that strategically exploits high energy density from a Li-ion battery electrode and high power density from a supercapacitor electrode. However, the performance and safety of hybrid devices are still major concerns due to the use of graphite anodes which form passivation layers with organic electrolytes at lower potentials. Here, we explore 2D nanosheets as both anode and cathode electrodes to build a high power system without compromising energy density. Owing to the high electrical conductivity and multivalent redox activity at higher potentials, the Li-ion intercalation electrode is capable of maintaining large energy density at higher current rates with less safety risk than conventional systems. Hybrid devices consisting of all in all 2D electrodes deliver energy density as high as 121 Wh g-1 (at 240 W kg-1) and retains 29 Wh g-1 at high power density of 3600 W kg-1.

Propulsion and Power Generation Capabilities of a Dense Plasma Focus (DPF) Fusion System for Future Military Aerospace Vehicles

International Nuclear Information System (INIS)

Knecht, Sean D.; Mead, Franklin B.; Thomas, Robert E.; Miley, George H.; Froning, David

2006-01-01

The objective of this study was to perform a parametric evaluation of the performance and interface characteristics of a dense plasma focus (DPF) fusion system in support of a USAF advanced military aerospace vehicle concept study. This vehicle is an aerospace plane that combines clean 'aneutronic' dense plasma focus (DPF) fusion power and propulsion technology, with advanced 'lifting body'-like airframe configurations utilizing air-breathing MHD propulsion and power technology within a reusable single-stage-to-orbit (SSTO) vehicle. The applied approach was to evaluate the fusion system details (geometry, power, T/W, system mass, etc.) of a baseline p-11B DPF propulsion device with Q = 3.0 and thruster efficiency, ηprop = 90% for a range of thrust, Isp and capacitor specific energy values. The baseline details were then kept constant and the values of Q and ηprop were varied to evaluate excess power generation for communication systems, pulsed-train plasmoid weapons, ultrahigh-power lasers, and gravity devices. Thrust values were varied between 100 kN and 1,000 kN with Isp of 1,500 s and 2,000 s, while capacitor specific energy was varied from 1 - 15 kJ/kg. Q was varied from 3.0 to 6.0, resulting in gigawatts of excess power. Thruster efficiency was varied from 0.9 to 1.0, resulting in hundreds of megawatts of excess power. Resulting system masses were on the order of 10's to 100's of metric tons with thrust-to-weight ratios ranging from 2.1 to 44.1, depending on capacitor specific energy. Such a high thrust/high Isp system with a high power generation capability would allow military versatility in sub-orbital space, as early as 2025, and beyond as early as 2050. This paper presents the results that coincide with a total system mass between 15 and 20 metric tons

The first operation of the superconducting optimized stellarator fusion device Wendelstein 7-X

Energy Technology Data Exchange (ETDEWEB)

Klinger, Thomas [Max-Planck-Institut fuer Plasmaphysik, Greifswald (Germany); Ernst-Moritz-Arndt Universitaet, Greifswald (Germany)

2016-07-01

The confinement of a high-temperature plasma by a suitable magnetic field is the most promising path to master nuclear fusion of Deuterium and Tritium on the scale of a reasonable power station. The two leading confinement concepts are the tokamak and the stellarator. Different from a tokamak, the stellarator does not require a strong current in the plasma but generates the magnetic field by external coils only. This has significant advantages, e.g. better stability properties and inherent steady-state capability. But stellarators need optimization, since ad hoc chosen magnetic field geometries lead to insufficient confinement properties, unfavourable plasma equilibria, and loss of fast particles. Wendelstein 7-X is a large (plasma volume 30 m{sup 3}) stellarator device with shaped superconducting coils that were determined via pure physics optimization criteria. After 19 years of construction, Wendelstein 7-X has now started operation. This talk introduces into the stellarator concept as a candidate for a future fusion power plant, summarizes the optimization principles, and presents the first experimental results with Helium and Hydrogen high temperature plasmas. An outlook on the physics program and the main goals of the project is given, too.

Development step toward fusion power plant and role of experimental reactor ITER

International Nuclear Information System (INIS)

Hiwatari, Ryouji; Asaoka, Yoshiyuki; Okano, Kunihiko

2005-01-01

The development of fusion energy is going into the experimental reactor stage, and the thermal energy from the fusion reaction will be generated in a plant scale through the ITER (International Thermonuclear Experimental Reactor) project. The remaining critical issue toward the realization of fusion energy is to map out the development strategy. Recently early realization approach as for the fusion energy development is being discussed in Japan, Europe, and the United States. This approach implies that the devices for a Demo reactor and a proto-type reactor as seen in the fast breeder reactor are combined into a single device in order to advance the fusion energy development. On the other hand, a clear development road map for fusion energy hasn't been suggested yet, and whether that early realization approach is feasible or not is still ambiguous. In order to realize the fusion energy as an user-friendly energy system, the suggestion of the development missions and the road map from the user-side point of view is instructive not only to Japanese but also to other country's development policy after the ITER project. In this report, first of all, the development missions from the user's point of view have been structured. Second, the development target required to demonstrate net electric generation and to introduce the fusion energy into the market is investigated, respectively. This investigation reveals that the completion of the ITER reference operation gives the outlook toward the demonstration of net electric generation and that the completion of the ITER advanced operation gives the possibility to introduce the fusion energy into the market. At last, the electric demonstration power plant Demo-CREST and the commercial power plant CREST are proposed to construct the development road map for fusion energy. (author)

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.

A study of hydrogen isotopes fuel control by wall effect in magnetic fusion devices

Energy Technology Data Exchange (ETDEWEB)

Motevalli, S.M., E-mail: motavali@umz.ac.ir; Safari, M.

2016-11-15

Highlights: • A particle balance model for the main plasma and wall inventory in magnetic fusion device has been represented. • The dependence of incident particles energy on the wall has been considered in 10–300 eV for the sputtering yield and recycling coefficient. • The effect of fueling methods on plasma density behavior has been studied. - Abstract: Determination of plasma density behavior in magnetic confinement system needs to study the plasma materials interaction in the facing components such as first wall, limiter and divertor. Recycling of hydrogen isotope is an effective parameter in plasma density rate and plasma fueling. Recycling coefficient over the long pulse operation, gets to the unity, so it has a significant effect on steady state in magnetic fusion devices. Typically, sputtered carbon atoms from the plasma facing components form hydrocarbons and they redeposit on the wall. In this case little rate of hydrogen loss occurs. In present work a zero dimensional particle equilibrium model has been represented to determine particles density rate in main plasma and wall inventory under recycling effect and codeposition of hydrogen in case of continues and discontinues fueling methods and effective parameters on the main plasma decay has been studied.

AxiaLIF system: minimally invasive device for presacral lumbar interbody spinal fusion.

Science.gov (United States)

Rapp, Steven M; Miller, Larry E; Block, Jon E

2011-01-01

Lumbar fusion is commonly performed to alleviate chronic low back and leg pain secondary to disc degeneration, spondylolisthesis with or without concomitant lumbar spinal stenosis, or chronic lumbar instability. However, the risk of iatrogenic injury during traditional anterior, posterior, and transforaminal open fusion surgery is significant. The axial lumbar interbody fusion (AxiaLIF) system is a minimally invasive fusion device that accesses the lumbar (L4-S1) intervertebral disc spaces via a reproducible presacral approach that avoids critical neurovascular and musculoligamentous structures. Since the AxiaLIF system received marketing clearance from the US Food and Drug Administration in 2004, clinical studies of this device have reported high fusion rates without implant subsidence, significant improvements in pain and function, and low complication rates. This paper describes the design and approach of this lumbar fusion system, details the indications for use, and summarizes the clinical experience with the AxiaLIF system to date.

Maximum neutron yeidls in experimental fusion devices

International Nuclear Information System (INIS)

Jassby, D.L.

1979-02-01

The optimal performances of 12 types of fusion devices are compared with regard to neutron production rate, neutrons per pulse, and fusion energy multiplication, Q/sub p/ (converted to the equivalent value in D-T operation). The record values in all categories are held by the beam-injected tokamak plasma, followed by other beam-target systems. The achieved values of Q/sub p/ for nearly all laboratory plasma fusion devices (magnetically or inertially confined) are found to roughly satisfy a common empirical scaling, Q/sub p/ approx. 10 -6 E/sub in//sup 3/2/, where E/sub in/ is the energy (in kilojoules) injected into the plasma during one or two energy confinement times, or the total energy delivered to the target for inertially confined systems. Fusion energy break-even (Q/sub p/ = 1) in any system apparently requires E/sub in/ approx. 10,000 kJ

Energetic Combustion Devices for Aerospace Propulsion and Power

Science.gov (United States)

Litchford, Ron J.

2000-01-01

Chemical reactions have long been the mainstay thermal energy source for aerospace propulsion and power. Although it is widely recognized that the intrinsic energy density limitations of chemical bonds place severe constraints on maximum realizable performance, it will likely be several years before systems based on high energy density nuclear fuels can be placed into routine service. In the mean time, efforts to develop high energy density chemicals and advanced combustion devices which can utilize such energetic fuels may yield worthwhile returns in overall system performance and cost. Current efforts in this vein are being carried out at NASA MSFC under the direction of the author in the areas of pulse detonation engine technology development and light metals combustion devices. Pulse detonation engines are touted as a low cost alternative to gas turbine engines and to conventional rocket engines, but actual performance and cost benefits have yet to be convincingly demonstrated. Light metal fueled engines also offer potential benefits in certain niche applications such as aluminum/CO2 fueled engines for endo-atmospheric Martian propulsion. Light metal fueled MHD generators also present promising opportunities with respect to electric power generation for electromagnetic launch assist. This presentation will discuss the applications potential of these concepts with respect to aero ace propulsion and power and will review the current status of the development efforts.

Physics, systems analysis and economics of fusion power plants

International Nuclear Information System (INIS)

Ward, D.J.

2006-01-01

Fusion power is being developed because of its large resource base, low environmental impact and high levels of intrinsic safety. It is important, however, to investigate the economics of a future fusion power plant to check that the electricity produced can, in fact, have a market. Using systems code analysis, including costing algorithms, this paper gives the cost of electricity expected from a range of fusion power plants, assuming that they are brought into successful operation. Although this paper does not purport to show that a first generation of fusion plants is likely to be the cheapest option for a future energy source, such plants look likely to have a market in some countries even without taking account of fusion's environmental advantages. With improved technological maturity fusion looks likely to have a widespread potential market particularly if the value of its environmental advantages are captured, for instance through avoiding a carbon tax. (author)

Analysis and Design Considerations of a High-Power Density, Dual Air Gap, Axial-Field Brushless, Permanent Magnet Motor.

Science.gov (United States)

Cho, Chahee Peter

1995-01-01

Until recently, brush dc motors have been the dominant drive system because they provide easily controlled motor speed over a wide range, rapid acceleration and deceleration, convenient control of position, and lower product cost. Despite these capabilities, the brush dc motor configuration does not satisfy the design requirements for the U.S. Navy's underwater propulsion applications. Technical advances in rare-earth permanent magnet materials, in high-power semiconductor transistor technology, and in various rotor position-sensing devices have made using brushless permanent magnet motors a viable alternative. This research investigates brushless permanent magnet motor technology, studying the merits of dual-air gap, axial -field, brushless, permanent magnet motor configuration in terms of power density, efficiency, and noise/vibration levels. Because the design objectives for underwater motor applications include high-power density, high-performance, and low-noise/vibration, the traditional, simplified equivalent circuit analysis methods to assist in meeting these goals were inadequate. This study presents the development and verification of detailed finite element analysis (FEA) models and lumped parameter circuit models that can calculate back electromotive force waveforms, inductance, cogging torque, energized torque, and eddy current power losses. It is the first thorough quantification of dual air-gap, axial -field, brushless, permanent magnet motor parameters and performance characteristics. The new methodology introduced in this research not only facilitates the design process of an axial field, brushless, permanent magnet motor but reinforces the idea that the high-power density, high-efficiency, and low-noise/vibration motor is attainable.

Overview on the high power excimer laser technology

Science.gov (United States)

Liu, Jingru

2013-05-01

High power excimer laser has essential applications in the fields of high energy density physics, inertial fusion energy and industry owing to its advantages such as short wavelength, high gain, wide bandwidth, energy scalable and repetition operating ability. This overview is aimed at an introduction and evaluation of enormous endeavor of the international high power excimer laser community in the last 30 years. The main technologies of high power excimer laser are reviewed, which include the pumping source technology, angular multiplexing and pulse compressing, beam-smoothing and homogenous irradiation, high efficiency and repetitive operation et al. A high power XeCl laser system developed in NINT of China is described in detail.

High power densities from high-temperature material interactions. [in thermionic energy conversion and metallic fluid heat pipes

Science.gov (United States)

Morris, J. F.

1981-01-01

Thermionic energy conversion (TEC) and metallic-fluid heat pipes (MFHPs), offering unique advantages in terrestrial and space energy processing by virtue of operating on working-fluid vaporization/condensation cycles that accept great thermal power densities at high temperatures, share complex materials problems. Simplified equations are presented that verify and solve such problems, suggesting the possibility of cost-effective applications in the near term for TEC and MFHP devices. Among the problems discussed are: the limitation of alkali-metal corrosion, protection against hot external gases, external and internal vaporization, interfacial reactions and diffusion, expansion coefficient matching, and creep deformation.

Structure Design and Analysis of High-Voltage Power Supply for ECRH

International Nuclear Information System (INIS)

Wang Lei; Huang Yiyun; Zhao Yanping; Zhang Jian; Yang Lei; Guo Wenjun

2014-01-01

In order to develop a high-voltage power supply (HVPS) with high quality parameters, not only its electrical circuit but also its structure should be studied in detail. In this paper, the structure design of the collector power supply for gyrotron is discussed first. Then the electrical field and potential simulations of its main devices are analyzed. Finally, relevant calculations and conclusions are given. (fusion engineering)

Controlled thermonuclear fusion power apparatus and method

International Nuclear Information System (INIS)

Bussard, R.W.; Coppi, B.

1982-01-01

This invention provides a modular fusion reactor system containing several fusion power cores, each of relatively small size and low cost. Energy from the cores is absorbed in the core structure and within a surrounding blanket, and the cores themselves may be individually removed from the blanket and replaced as they deteriorate from high radiation flux damage

Thulium heat source for high-endurance and high-energy density power systems

International Nuclear Information System (INIS)

Walter, C.E.; Kammeraad, J.E.; Van Konynenburg, R.; VanSant, J.H.

1991-05-01

We are studying the performance characteristics of radioisotope heat source designs for high-endurance and high-energy-density power systems that use thulium-170. Heat sources in the power range of 5--50 kW th coupled with a power conversion efficiency of ∼30%, can easily satisfy current missions for autonomous underwater vehicles. New naval missions will be possible because thulium isotope power systems have a factor of one-to-two hundred higher endurance and energy density than chemical and electrochemical systems. Thulium-170 also has several other attractive features, including the fact that it decays to stable ytterbium-170 with a half-life of four months. For terrestrial applications, refueling on that time scale should be acceptable in view of the advantage of its benign decay. The heat source designs we are studying account for the requirements of isotope production, shielding, and integration with power conversion components. These requirements are driven by environmental and safety considerations. Thulium is present in the form of thin refractory thulia disks that allow power conversion at high peak temperature. We give estimates of power system state points, performance, mass, and volume characteristics. Monte Carlo radiation analysis provides a detailed assessment of shield requirements and heat transfer under normal and distressed conditions is also considered. 11 refs., 7 figs., 4 tabs

Tritium inventory and recovery in next-step fusion devices

International Nuclear Information System (INIS)

Causey, R.A.; Brooks, J.N.; Federici, G.

2002-01-01

Future fusion devices will use tritium and deuterium fuel. Because tritium is both radioactive and expensive, it is absolutely necessary that there be an understanding of the tritium retention characteristics of the materials used in these devices as well as how to recover the tritium. There are three materials that are strong candidates for plasma-facing-material use in next-step fusion devices. These are beryllium, tungsten, and carbon. While beryllium has the disadvantage of high sputtering and low melting point (which limits its power handling capabilities in divertor areas), it has the advantages of being a low-Z material with a good thermal conductivity and the ability to get oxygen from the plasma. Due to beryllium's very low solubility for hydrogen, implantation of beryllium with deuterium and tritium results in a saturated layer in the very near-surface with limited inventory (J. Nucl. Mater. 273 (1999) 1). Unfortunately, there are nuclear reactions generated by neutrons that will breed tritium and helium in the material bulk (J. Nucl. Mater. 179 (1991) 329). This process will lead to a substantial tritium inventory in the bulk of the beryllium after long-term neutron exposure (i.e. well beyond the operation life time of a next-step reactor like ITER). Tungsten is a high-Z material that will be used in the divertor region of next-step devices (e.g. ITER) and possibly as a first wall material in later devices. The divertor is the preferred location for tungsten use because net erosion is very low there due to low sputtering and high redeposition. While experiments are still continuing on tritium retention in tungsten, present data suggest that relatively low tritium inventories will result with this material (J. Nucl. Mater. 290-293 (2001) 505). For tritium inventories, carbon is the problem material. Neutron damage to the graphite can result in substantial bulk tritium retention (J. Nucl. Mater. 191-194 (1992) 368), and codeposition of the sputtered carbon

Biopolymer-nanocarbon composite electrodes for use as high-energy high-power density electrodes

Science.gov (United States)

Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Zhu, Jingyi; Podila, Ramakrishna; Rao, Apparao

2014-03-01

Supercapacitors (SCs) address our current energy storage and delivery needs by combining the high power, rapid switching, and exceptional cycle life of a capacitor with the high energy density of a battery. Although activated carbon is extensively used as a supercapacitor electrode due to its inexpensive nature, its low specific capacitance (100-120 F/g) fundamentally limits the energy density of SCs. We demonstrate that a nano-carbon based mechanically robust, electrically conducting, free-standing buckypaper electrode modified with an inexpensive biorenewable polymer, viz., lignin increases the electrode's specific capacitance (~ 600-700 F/g) while maintaining rapid discharge rates. In these systems, the carbon nanomaterials provide the high surface area, electrical conductivity and porosity, while the redox polymers provide a mechanism for charge storage through Faradaic charge transfer. The design of redox polymers and their incorporation into nanomaterial electrodes will be discussed with a focus on enabling high power and high energy density electrodes. Research supported by US NSF CMMI Grant 1246800.

Filter and window assemblies for high power insertion device synchrotron radiation sources

International Nuclear Information System (INIS)

Khounsary, A.M.; Viccaro, P.J.; Kuzay, T.M.

1992-01-01

The powerful beams of x-ray radiation generated by insertion devices at high power synchrotron facilities deposit substantial amounts of localized heat in the front end and optical components that they intercept. X-ray beams from undulator sources, in particular, are confined to very narrow solid angles and therefore impose very high absorbed heat fluxes. This paper is devoted to a detailed study of the design of windows for the Advanced Photon Source undulators and wigglers, emphasizing alternative design concepts, material considerations, and cooling techniques necessary for handling the high heat load of the insertion devices. Various designs are thermally and structurally analyzed by numerically simulating full-power operating conditions. This analysis also has relevance to the design and development of other beam line components which are subjected to the high heat loads of insertion devices

A broadband high-efficiency Doherty power amplifier using symmetrical devices

Science.gov (United States)

Cheng, Zhiqun; Zhang, Ming; Li, Jiangzhou; Liu, Guohua

2018-04-01

This paper proposes a method for broadband and high-efficiency amplification of Doherty power amplifier (DPA) using symmetric devices. In order to achieve the perfect load modulation, the carrier amplifier output circuit total power length is designed to odd multiple of 90°, and the peak amplifier output total power length is designed to even multiple of 180°. The proposed method is demonstrated by designing a broadband high-efficiency DPA using identical 10-W packaged GaN HEMT devices. Measurement results show that over 51% drain efficiency is achieved at 6-dB back-off power, over the frequency band of 1.9–2.4 GHz. Project supported by the National Natural Science Foundation of China (No. 60123456), the Zhejiang Provincial Natural Science Foundation of China (No. LZ16F010001), and the Zhejiang Provincial Public Technology Research Project (No. 2016C31070).

Monitoring device for the reactor power distribution

International Nuclear Information System (INIS)

Uematsu, Hitoshi; Tsuiki, Makoto

1982-01-01

Purpose: To enable accurate monitoring for the power distribution in a short time, as well as independent detection for in-core neutron flux detectors in abnormal operation due to failures or like other causes to thereby surely provide reliable substitute values. Constitution: Counted values are inputted from a reactor core present status data detector by a power distribution calculation device to calculate the in-core neutron flux density and the power distribution based on previously stored physical models. While on the other hand, counted value from the in-core neutron detectors and the neutron flux distribution and the power distribution calculated from the power distribution calculation device are inputted from a BCF calculation device to compensate the counting errors incorporated in the counted value from the in-core neutron flux detectors and the calculation errors incorporated in the power distribution calculated in the power distribution calculation device respectively and thereby calculate the power distribution in the reactor core. Further, necessary data are inputted to the power distribution calculation device by an input/output device and the results calculated in the BCF calculation device are displayed. (Aizawa, K.)

High-power density miniscale power generation and energy harvesting systems

International Nuclear Information System (INIS)

Lyshevski, Sergey Edward

2011-01-01

This paper reports design, analysis, evaluations and characterization of miniscale self-sustained power generation systems. Our ultimate objective is to guarantee highly-efficient mechanical-to-electrical energy conversion, ensure premier wind- or hydro-energy harvesting capabilities, enable electric machinery and power electronics solutions, stabilize output voltage, etc. By performing the advanced scalable power generation system design, we enable miniscale energy sources and energy harvesting technologies. The proposed systems integrate: (1) turbine which rotates a radial- or axial-topology permanent-magnet synchronous generator at variable angular velocity depending on flow rate, speed and load, and, (2) power electronic module with controllable rectifier, soft-switching converter and energy storage stages. These scalable energy systems can be utilized as miniscale auxiliary and self-sustained power units in various applications, such as, aerospace, automotive, biotechnology, biomedical, and marine. The proposed systems uniquely suit various submersible and harsh environment applications. Due to operation in dynamic rapidly-changing envelopes (variable speed, load changes, etc.), sound solutions are researched, proposed and verified. We focus on enabling system organizations utilizing advanced developments for various components, such as generators, converters, and energy storage. Basic, applied and experimental findings are reported. The prototypes of integrated power generation systems were tested, characterized and evaluated. It is documented that high-power density, high efficiency, robustness and other enabling capabilities are achieved. The results and solutions are scalable from micro (∼100 μW) to medium (∼100 kW) and heavy-duty (sub-megawatt) auxiliary and power systems.

Performance and reliability of TPE-2 device with pulsed high power source

International Nuclear Information System (INIS)

Sato, Y.; Takeda, S.; Kiyama, S.

1987-01-01

The performance and the reliability of TPE-2 device with pulsed high power sources are described. To obtain the stable high beta plasma, the reproducibility and the reliability of the pulsed power sources must be maintained. A new power crowbar system with high efficiency and the switches with low jitter time are adopted to the bank system. A monitor system which always watches the operational states of the switches is developed too, and applied for the fast rising capacitor banks of TPE-2 device. The reliable operation for the bank has been realized, based on the data of switch monitor system

Particle and impurity control in toroidal fusion devices

International Nuclear Information System (INIS)

Wootton, A.J.

1986-01-01

A review of working particle and impurity control techniques used in and proposed for magnetic fusion devices is presented. The requirements of both present-day machines and envisaged fusion reactors are considered. The various techniques which have been proposed are characterized by whether they affect sources, sinks, or fluxes; in many cases a particular method or device can appear in more than one category. Examples are drawn from published results. The solutions proposed for the large devices which will be operating during the next 5 years are discussed

Utilization of a Network of Small Magnetic Confinement Fusion Devices for Mainstream Fusion Research. Report of a Coordinated Research Project 2011–2016

International Nuclear Information System (INIS)

2016-12-01

The IAEA actively promotes the development of controlled fusion as a source of energy. Through its coordinated research activities, the IAEA helps Member States to exchange and establish scientific and technical knowledge required for the design, construction and operation of a fusion reactor. Due to their compactness, flexibility and low operation costs, small fusion devices are a great resource for supporting and accelerating the development of mainstream fusion research on large fusion devices such as the International Thermonuclear Experimental Reactor. They play an important role in investigating the physics of controlled fusion, developing innovative technologies and diagnostics, testing new materials, training highly qualified personnel for larger fusion facilities, and supporting educational programmes for young scientists. This publication reports on the research work accomplished within the framework of the Coordinated Research Project (CRP) on Utilization of the Network of Small Magnetic Confinement Fusion Devices for Mainstream Fusion Research, organized and conducted by the IAEA in 2011–2016. The CRP has contributed to the coordination of a network of research institutions, thereby enhancing international collaboration through scientific visits, joint experiments and the exchange of information and equipment. A total of 16 institutions and 14 devices from 13 Member States participated in this CRP (Belgium, Bulgaria, Canada, China, Costa Rica, the Czech Republic, the Islamic Republic of Iran, Kazakhstan, Pakistan, Portugal, the Russian Federation, Ukraine and the United Kingdom).

Radio-frequency-assisted current startup in the Fusion Engineering Device

International Nuclear Information System (INIS)

Borowski, S.K.; Kammash, T.; Martin Peng, Y.K.

1984-01-01

Auxiliary radio-frequency (RF) heating of electrons before and during the current rise phase of a large tokamak, such as the Fusion Engineering Device (FED) (R 0 = 4.8 m, a = 1.3 m, sigma = 1.6, B(R 0 ) = 3.62 T), is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at about90 GHz is used to create a small volume of high conductivity plasma (T /sub e/ approx. = 100 eV, n /sub e/ approx. = 10 19 m -3 ) near the upper hybrid resonance (UHR) region. This plasma conditioning, referred to as preheating, permits a small radius (a 0 approx. = 0.2 to 0.4 m) current channel to be established with a relatively low initial loop voltage (less than or equal to 25 V as opposed to about 100 V without rf assist). During the subsequent plasma expansion and current rise phase, a combination of rf heating (up to 5 MW) and linear current ramping leads to a substantial savings in voltseconds by (a) minimizing the resistive flux consumption and (b) producing broad current density profiles. (With such broad profiles, the internal flux requirements are maintained at or near the flat profile limit.)

Properties of plasma sheath with ion temperature in magnetic fusion devices

International Nuclear Information System (INIS)

Liu Jinyuan; Wang Feng; Sun Jizhong

2011-01-01

The plasma sheath properties in a strong magnetic field are investigated in this work using a steady state two-fluid model. The motion of ions is affected heavily by the strong magnetic field in fusion devices; meanwhile, the effect of ion temperature cannot be neglected for the plasma in such devices. A criterion for the plasma sheath in a strong magnetic field, which differs from the well-known Bohm criterion for low temperature plasma sheath, is established theoretically with a fluid model. The fluid model is then solved numerically to obtain detailed sheath information under different ion temperatures, plasma densities, and magnetic field strengths.

Fast optical shutters for Nova, a high power fusion laser

International Nuclear Information System (INIS)

Bradley, L.P.; Gagnon, W.L.; Carder, B.M.

1977-01-01

Preliminary design and performance test results for fast optical shutters intended for use in the Nova high power fusion laser system are briefly described. Both an opening shutter to protect the pellet target from amplified spontaneous emission (ASE), and a closing shutter to protect the laser from light reflected back from the target are discussed. Faraday rotators, synchronized by a 400 Hz oscillator, provide an opening shutter mechanism with an opening time of approximately 10 μs. A plasma closing shutter, employing electrical sublimation of a foil, provide a shutter closing time of 70 ns +- 20 ns. Energy for foil sublimation is provided by discharge of a 42 J capacitor bank. Implementation of these shutter techniques in the Nova system is anticipated to improve laser output power and efficiency

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)

Inertial fusion commercial power plants

International Nuclear Information System (INIS)

Logan, B.G.

1994-01-01

This presentation discusses the motivation for inertial fusion energy, a brief synopsis of five recently-completed inertial fusion power plant designs, some general conclusions drawn from these studies, and an example of an IFE hydrogen synfuel plant to suggest that future fusion studies consider broadening fusion use to low-emission fuels production as well as electricity

A high frequency, high power CARM proposal for the DEMO ECRH system

International Nuclear Information System (INIS)

Mirizzi, Francesco; Spassovsky, Ivan; Ceccuzzi, Silvio; Dattoli, Giuseppe; Di Palma, Emanuele; Doria, Andrea; Gallerano, Gianpiero; Lampasi, Alessandro; Maffia, Giuseppe; Ravera, GianLuca; Sabia, Elio; Tuccillo, Angelo Antonio; Zito, Pietro

2015-01-01

Highlights: • ECRH system for DEMO. • Cyclotron Auto-Resonance Maser (CARM) devices. • Relativistic electron beams. • Bragg reflectors. • High voltage pulse modulators. - Abstract: ECRH&CD systems are extensively used on tokamak plasmas due to their capability of highly tailored power deposition, allowing very localised heating and non-inductive current drive, useful for MHD and profiles control. The high electron temperatures expected in DEMO will require ECRH systems with operating frequency in the 200–300 GHz range, equipped with a reasonable number of high power (P ≥ 1 MW) CW RF sources, for allowing central RF power deposition. In this frame the ENEA Fusion Department (Frascati) is coordinating a task force aimed at the study and realisation of a suitable high power, high frequency reliable source.

A high frequency, high power CARM proposal for the DEMO ECRH system

Energy Technology Data Exchange (ETDEWEB)

Mirizzi, Francesco, E-mail: francesco.mirizzi@enea.it [Consorzio CREATE, Via Claudio 21, I-80125 Napoli (Italy); Spassovsky, Ivan [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Ceccuzzi, Silvio [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Dattoli, Giuseppe; Di Palma, Emanuele; Doria, Andrea; Gallerano, Gianpiero [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Lampasi, Alessandro; Maffia, Giuseppe; Ravera, GianLuca [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Sabia, Elio [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Tuccillo, Angelo Antonio; Zito, Pietro [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy)

2015-10-15

Highlights: • ECRH system for DEMO. • Cyclotron Auto-Resonance Maser (CARM) devices. • Relativistic electron beams. • Bragg reflectors. • High voltage pulse modulators. - Abstract: ECRH&CD systems are extensively used on tokamak plasmas due to their capability of highly tailored power deposition, allowing very localised heating and non-inductive current drive, useful for MHD and profiles control. The high electron temperatures expected in DEMO will require ECRH systems with operating frequency in the 200–300 GHz range, equipped with a reasonable number of high power (P ≥ 1 MW) CW RF sources, for allowing central RF power deposition. In this frame the ENEA Fusion Department (Frascati) is coordinating a task force aimed at the study and realisation of a suitable high power, high frequency reliable source.

Design study of an indirect cooling superconducting magnet for a fusion device

International Nuclear Information System (INIS)

Mito, Toshiyuki; Hemmi, Tsutomu

2009-01-01

The design study of superconducting magnets adapting a new coil winding scheme of an indirect cooling method is reported. The superconducting magnet system for the spherical tokamak (ST), which is proposed to study the steady state plasma experiment with Q - equiv-1, requires high performances with a high current density compared to the ordinal magnet design because of its tight spatial restriction. The superconducting magnet system for the fusion device has been used in the condition of high magnetic field, high electromagnetic force, and high heat load. The pool boiling liquid helium cooling outside of the conductor or the forced flow of supercritical helium cooling inside of the conductor, such as cable-in-conduit conductors, were used so far for the cooling method of the superconducting magnet for a fusion application. The pool cooling magnet has the disadvantages of low mechanical rigidities and low withstand voltages of the coil windings. The forced flow cooling magnet with cable-in-conduit conductors has the disadvantages of the restriction of the coil design because of the path of the electric current must be the same as that of the cooling channel for refrigerant. The path of the electric current and that of the cooling channel for refrigerant can be independently designed by adopting the indirect cooling method that inserts the independent cooling panel in the coil windings and cools the conductor from the outside. Therefore the optimization of the coil windings structure can be attempted. It was shown that the superconducting magnet design of the high current density became possible by the indirect cooling method compared with those of the conventional cooling scheme. (author)

Laser fusion and precision engineering

International Nuclear Information System (INIS)

Nakai, Sadao

1989-01-01

The development of laser nuclear fusion energy for attaining the self supply of energy in Japan and establishing the future perspective as the nation is based in the wide fields of high level science and technology. Therefore to its promotion, large expectation is placed as the powerful traction for the development of creative science and technology which are particularly necessary in Japan. The research on laser nuclear fusion advances steadily in the elucidation of the physics of pellet implosion which is its basic concept and compressed plasma parameters. In September, 1986, the number of neutron generation 10 13 , and in October, 1988, the high density compression 600 times as high as solid density have been achieved. Based on these results, now the laser nuclear fusion is in the situation to begin the attainment of ignition condition for nuclear fusion and the realization of break even. The optical components, high power laser technology, fuel pellet production, high resolution measurement, the simulation of implosion using a supercomputer and so on are closely related to precision engineering. In this report, the mechanism of laser nuclear fusion, the present status of its research, and the basic technologies and precision engineering are described. (K.I.)

Radiation control in fusion plasmas by magnetic confinement

International Nuclear Information System (INIS)

Dachicourt, R.

2012-10-01

The present work addresses two important issues for the industrial use of fusion: plasma radiation control, as a part of the more general power handling issue, and high density tokamak operation. These two issues will be most critical in the demonstration reactor, called DEMO, intermediate step between ITER and a future commercial reactor. For DEMO, the need to radiate a large fraction of the power so as to limit the peak power load on the divertor will be a key constraint. High confinement will have to be combined with high radiated power fraction, and the required level of plasma purity. The main achievement of this thesis is to have shown experimental evidence of the existence of a stable plasma regime meeting the most critical requirements of a DEMO scenario: an electron density up to 40% above the Greenwald value, together with a fraction of radiated power close to 80%, with a good energy confinement and limited dilution. The plasma is additionally heated with ion cyclotron waves in a central electron heating scenario, featuring alpha particle heating. The original observations reported in this work bring highly valuable new pieces of information both to the physics of the tokamak edge layer and to the construction of an 'integrated operational scenario' required to successfully operate fusion devices. In the way for getting high density plasmas, the new observations involve the following topics. First, the formation of a poloidal asymmetry in the edge electron density profile, with a maximum density located close to toroidal pumped limiter. This asymmetry occurs inside the separatrix, with a constant plasma pressure on magnetic surfaces. Secondly, a correlative decrease of the electron temperature in the same edge region. Thirdly, the excellent coupling capabilities of the ICRH waves, up to a central line averaged electron density of 1.4 times the Greenwald density. Fourthly, a poloidally asymmetric edge radiation region, providing the dissipation of 80% of

Mechanical Property Characteristics of Butt-Fusion Joint of High Density Polyethylene Pipe for NPP Safety Class Application

International Nuclear Information System (INIS)

Oh, Youngjin; Kim, Kyoungsu; Lee, Seunggun; Park, Heungbae; Yu, Jeongho; Kim, Jongsung; Kim, Jeonghyun; Jang, Changheui; Choi, Sunwoong

2013-01-01

Several NPPs in United States replaced parts of sea water or raw water system pipes to HDPE (high density polyethylene) pipes, which have outstanding resistance for oxidation and seismic loading. ASME B and PV code committee developed Code Case N-755, which describes rules for the construction of Safety Class 3 polyethylene pressure piping components. Several NPP's in US proposed relief requests in order to apply Code Case N-755. Although US NRC permitted using Code Case N-755 and HDPE materials for Class 3 buried piping, their permission was limited to only 10 years because of several concerns for material performance of HDPE. US NRC's major concerns are about material properties and the quality of fusion zone of HDPE. In this study, material property tests for HDPE fusion zone are conducted with varying standard fusion procedures. Mechanical property tests for fused material for HDPE pipes were conducted. Fused material shows lower toughness than base material and fused material of lower fusion pressure shows higher toughness than that of higher fusion pressure

High current density M-type cathodes for vacuum electron devices

International Nuclear Information System (INIS)

Li Ji; Yu Zhiqiang; Shao Wensheng; Zhang Ke; Gao Yujuan; Yuan Haiqing; Wang Hui; Huang Kaizhi; Chen Qilue; Yan Suqiu; Cai Shaolun

2005-01-01

We investigated high current density emission capabilities of M-type cathodes used for vacuum electron devices (VEDs). The experimental results of emission and lifetime evaluating in both close-spaced diode structure and electron gun testing vehicles are given. Emission current densities measured in the diode structure at 1020 deg. C Br in the CW mode were above 10 A/cm 2 ; while in electron gun testing vehicles, emission current densities were above 8 A/cm 2 in CW mode and above 32 A/cm 2 in pulsed mode, respectively. The current density above 94 A/cm 2 has been acquired in no. 0306 electron gun vehicle while the practical temperature is 1060 deg. C Br . For a comparison some of the data from I-scandate cathodes are presented. Finally, several application examples in practical travelling wave tubes (TWTs) and multi beam klystrons (MBKs) are also reported

Muon catalyzed fusion under compressive conditions

International Nuclear Information System (INIS)

Cripps, G.; Goel, B.; Harms, A.A.

1991-01-01

The viability of a symbiotic combination of Muon Catalyzed Fusion (μCF) and high density generation processes has been investigated. The muon catalyzed fusion reaction rates are formulated in the temperature and density range found under moderate compressive conditions. Simplified energy gain and power balance calculations indicate that significant energy gain occurs only if standard type deuterium-tritium (dt) fusion is ignited. A computer simulation of the hydrodynamics and fusion kinetics of a spherical deuterium-tritium pellet implosion including muons is performed. Using the muon catalyzed fusion reaction rates formulated and under ideal conditions, the pellet ignites (and thus has a significant energy gain) only if the initial muon concentration is approximately 10 17 cm -3 . The muons need to be delivered to the pellet within a very short-time (≅ 1 ns). The muon pulse required in order to make the high density and temperature muon catalyzed fusion scheme viable is beyond the present technology for muon production. (orig.) [de

High Power Density Motors

Science.gov (United States)

Kascak, Daniel J.

2004-01-01

With the growing concerns of global warming, the need for pollution-free vehicles is ever increasing. Pollution-free flight is one of NASA's goals for the 21" Century. , One method of approaching that goal is hydrogen-fueled aircraft that use fuel cells or turbo- generators to develop electric power that can drive electric motors that turn the aircraft's propulsive fans or propellers. Hydrogen fuel would likely be carried as a liquid, stored in tanks at its boiling point of 20.5 K (-422.5 F). Conventional electric motors, however, are far too heavy (for a given horsepower) to use on aircraft. Fortunately the liquid hydrogen fuel can provide essentially free refrigeration that can be used to cool the windings of motors before the hydrogen is used for fuel. Either High Temperature Superconductors (HTS) or high purity metals such as copper or aluminum may be used in the motor windings. Superconductors have essentially zero electrical resistance to steady current. The electrical resistance of high purity aluminum or copper near liquid hydrogen temperature can be l/lOO* or less of the room temperature resistance. These conductors could provide higher motor efficiency than normal room-temperature motors achieve. But much more importantly, these conductors can carry ten to a hundred times more current than copper conductors do in normal motors operating at room temperature. This is a consequence of the low electrical resistance and of good heat transfer coefficients in boiling LH2. Thus the conductors can produce higher magnetic field strengths and consequently higher motor torque and power. Designs, analysis and actual cryogenic motor tests show that such cryogenic motors could produce three or more times as much power per unit weight as turbine engines can, whereas conventional motors produce only 1/5 as much power per weight as turbine engines. This summer work has been done with Litz wire to maximize the current density. The current is limited by the amount of heat it

Characterization of high temperature superconductor cables for magnet toroidal field coils of the DEMO fusion power plant

CERN Document Server

Bayer, Christoph M

2017-01-01

Nuclear fusion is a key technology to satisfy the basic demand for electric energy sustainably. The official EUROfusion schedule foresees a first industrial DEMOnstration Fusion Power Plant for 2050. In this work several high temperature superconductor sub-size cables are investigated for their applicability in large scale DEMO toroidal field coils. Main focus lies on the electromechanical stability under the influence of high Lorentz forces at peak magnetic fields of up to 12 T.

Characterization of high temperature superconductor cables for magnet toroidal field coils of the DEMO fusion power plant

Energy Technology Data Exchange (ETDEWEB)

Bayer, Christoph M.

2017-05-01

Nuclear fusion is a key technology to satisfy the basic demand for electric energy sustainably. The official EUROfusion schedule foresees a first industrial DEMOnstration Fusion Power Plant for 2050. In this work several high temperature superconductor sub-size cables are investigated for their applicability in large scale DEMO toroidal field coils. Main focus lies on the electromechanical stability under the influence of high Lorentz forces at peak magnetic fields of up to 12 T.

Institute for Fusion Research and Large Helical Device program

International Nuclear Information System (INIS)

Iiyoshi, Atsuo

1989-01-01

In the research on nuclear fusion, the final objective is to materialize nuclear fusion reactors, and for the purpose, it is necessary to cause nuclear combustion by making the plasma of higher than 100 million deg and confine it for a certain time. So far in various universities, the researches on diversified fusion processes have been advanced, but in February, 1986, the Science Council issued the report 'Nuclear fusion research in universities hereafter'. As the next large scale device, an external conductor system helical device was decided, and it is desirable to found the organization for joint utilization by national universities to promote the project. The researches on the other processes are continued by utilizing the existing facilitie. The reason of selecting a helical device is the data base of the researches carried out so far can be utilized sufficiently, it is sufficiently novel even after 10 years from now, and many researchers can be collected. The place of the research is Toki City, Gifu Prefecture, where the Institute of Plasma Physics, Nagoya University, is to be moved. The basic concept of the superconducting helical device project, the trend of nuclear fusion development in the world, the physical research using a helical system and so on are reported. (Kako, I.)

Comparison of nuclear irradiation parameters of fusion breeder materials in high flux fission test reactors and a fusion power demonstration reactor

International Nuclear Information System (INIS)

Fischer, U.; Herring, S.; Hogenbirk, A.; Leichtle, D.; Nagao, Y.; Pijlgroms, B.J.; Ying, A.

2000-01-01

Nuclear irradiation parameters relevant to displacement damage and burn-up of the breeder materials Li 2 O, Li 4 SiO 4 and Li 2 TiO 3 have been evaluated and compared for a fusion power demonstration reactor and the high flux fission test reactor (HFR), Petten, the advanced test reactor (ATR, INEL) and the Japanese material test reactor (JMTR, JAERI). Based on detailed nuclear reactor calculations with the MCNP Monte Carlo code and binary collision approximation (BCA) computer simulations of the displacement damage in the polyatomic lattices with MARLOWE, it has been investigated how well the considered HFRs can meet the requirements for a fusion power reactor relevant irradiation. It is shown that a breeder material irradiation in these fission test reactors is well suited in this regard when the neutron spectrum is well tailored and the 6 Li-enrichment is properly chosen. Requirements for the relevant nuclear irradiation parameters such as the displacement damage accumulation, the lithium burn-up and the damage production function W(T) can be met when taking into account these prerequisites. Irradiation times in the order of 2-3 full power years are necessary for the HFR to achieve the peak values of the considered fusion power Demo reactor blanket with regard to the burn-up and, at the same time, the dpa accumulation

High-power density miniscale power generation and energy harvesting systems

Energy Technology Data Exchange (ETDEWEB)

Lyshevski, Sergey Edward [Department of Electrical and Microelectronics Engineering, Rochester Institute of Technology, Rochester, NY 14623-5603 (United States)

2011-01-15

This paper reports design, analysis, evaluations and characterization of miniscale self-sustained power generation systems. Our ultimate objective is to guarantee highly-efficient mechanical-to-electrical energy conversion, ensure premier wind- or hydro-energy harvesting capabilities, enable electric machinery and power electronics solutions, stabilize output voltage, etc. By performing the advanced scalable power generation system design, we enable miniscale energy sources and energy harvesting technologies. The proposed systems integrate: (1) turbine which rotates a radial- or axial-topology permanent-magnet synchronous generator at variable angular velocity depending on flow rate, speed and load, and, (2) power electronic module with controllable rectifier, soft-switching converter and energy storage stages. These scalable energy systems can be utilized as miniscale auxiliary and self-sustained power units in various applications, such as, aerospace, automotive, biotechnology, biomedical, and marine. The proposed systems uniquely suit various submersible and harsh environment applications. Due to operation in dynamic rapidly-changing envelopes (variable speed, load changes, etc.), sound solutions are researched, proposed and verified. We focus on enabling system organizations utilizing advanced developments for various components, such as generators, converters, and energy storage. Basic, applied and experimental findings are reported. The prototypes of integrated power generation systems were tested, characterized and evaluated. It is documented that high-power density, high efficiency, robustness and other enabling capabilities are achieved. The results and solutions are scalable from micro ({proportional_to}100 {mu}W) to medium ({proportional_to}100 kW) and heavy-duty (sub-megawatt) auxiliary and power systems. (author)

Modelling of surface evolution of rough surface on divertor target in fusion devices

International Nuclear Information System (INIS)

Dai, Shuyu; Liu, Shengguang; Sun, Jizhong; Kirschner, A.; Kawamura, G.; Tskhakaya, D.; Ding, Rui; Luo, Guangnan; Wang, Dezhen

2015-01-01

Highlights: • We study the surface evolution of rough surface on divertor target in fusion devices. • The effects of gyration motion and E × B drift affect 3D angular distribution. • A larger magnetic field angle leads to a reduced net eroded areal density. • The rough surface evolution affects the physical sputtering yield. - Abstract: The 3D Monte-Carlo code SURO has been used to study the surface evolution of rough surface on the divertor target in fusion devices. The edge plasma at divertor region is modelled by the SDPIC code and used as input data for SURO. Coupled with SDPIC, SURO can perform more sophisticated simulations to calculate the local angle and surface evolution of rough surface. The simulation results show that the incident direction of magnetic field, gyration and E × B force has a significant impact on 3D angular distribution of background plasma and accordingly on the erosion of rough surface. The net eroded areal density of rough surface is studied by varying the magnetic field angle with surface normal. The evolution of the microscopic morphology of rough surface can lead to a significant change in the physical sputtering yield

Conceptual radiation shielding design of superconducting tokamak fusion device by PHITS

International Nuclear Information System (INIS)

Sukegawa, Atsuhiko M.; Kawasaki, Hiromitsu; Okuno, Koichi

2010-01-01

A complete 3D neutron and photon transport analysis by Monte Carlo transport code system PHITS (Particle and Heavy Ion Transport code System) have been performed for superconducting tokamak fusion device such as JT-60 Super Advanced (JT-60SA). It is possible to make use of PHITS in the port streaming analysis around the devices for the tokamak fusion device, the duct streaming analysis in the building where the device is installed, and the sky shine analysis for the site boundary. The neutron transport analysis by PHITS makes it clear that the shielding performance of the superconducting tokamak fusion device with the cryostat is improved by the graphical results. From the standpoint of the port streaming and the duct streaming, it is necessary to calculate by 3D Monte Carlo code such as PHITS for the neutronics analysis of superconducting tokamak fusion device. (author)

High energy and power density asymmetric supercapacitors using electrospun cobalt oxide nanowire anode

Science.gov (United States)

Vidyadharan, Baiju; Aziz, Radhiyah Abd; Misnon, Izan Izwan; Anil Kumar, Gopinathan M.; Ismail, Jamil; Yusoff, Mashitah M.; Jose, Rajan

2014-12-01

Electrochemical materials are under rigorous search for building advanced energy storage devices. Herein, supercapacitive properties of highly crystalline and ultrathin cobalt oxide (Co3O4) nanowires (diameter ∼30-60 nm) synthesized using an aqueous polymeric solution based electrospinning process are reported. These nanowire electrodes show a specific capacitance (CS) of ∼1110 F g-1 in 6 M KOH at a current density of 1 A g-1 with coulombic efficiency ∼100%. Asymmetric supercapacitors (ASCs) (CS ∼175 F g-1 at 2 A g-1 galvanostatic cycling) are fabricated using the Co3O4 as anode and commercial activated carbon (AC) as cathode and compared their performance with symmetric electrochemical double layer capacitors (EDLCs) fabricated using AC (CS ∼31 F g-1 at 2 A g-1 galvanostatic cycling). The Co3O4//AC ASCs deliver specific energy densities (ES) of 47.6, 35.4, 20 and 8 Wh kg-1 at specific power densities (PS) 1392, 3500, 7000 and 7400 W kg-1, respectively. The performance of ASCs is much superior to the control EDLCs, which deliver ES of 9.2, 8.9, 8.4 and 6.8 Wh kg-1 at PS 358, 695, 1400 and 3500 W kg-1, respectively. The ASCs show nearly six times higher energy density (∼47.6 Wh kg-1) than EDLC (8.4 Wh kg-1) without compromising its power density (∼1400 W kg-1) at similar galvanostatic cycling conditions (2 A g-1).

Fusion power plant for water desalination and reuse

International Nuclear Information System (INIS)

Borisov, A.A.; Desjatov, A.V.; Izvolsky, I.M.; Serikov, A.G.; Smirnov, V.P.; Smirnov, Yu.N.; Shatalov, G.E.; Sheludjakov, S.V.; Vasiliev, N.N.; Velikhov, E.P.

2001-01-01

Development of industry and agriculture demands a huge fresh water consumption. Exhaust of water sources together with pollution arises a difficult problem of population, industry, and agriculture water supply. Request for additional water supply in next 50 years is expected from industrial and agricultural sectors of many countries in the world. The presented study of fusion power plant for water desalination and reuse is aimed to widen a range of possible fusion industrial applications. Fusion offers a safe, long-term source of energy with abundant resources and major environmental advantages. Thus fusion can provide an attractive energy option to society in the next century. Fusion power tokamak reactor based on RF DEMO-S project [Proc. ISFNT-5 (2000) in press; Conceptual study of RF DEMO-S fusion reactor (2000)] was chosen as an energy source. A steady state operation mode is considered with thermal power of 4.0 GW. The reactor has to operate in steady-state plasma mode with high fraction of bootstrap current. Average plant availability of ∼0.7 is required. A conventional type of water cooled blanket is the first choice, helium or lithium coolants are under consideration. Desalination plant includes two units: reverse osmosis and distillation. Heat to electricity conversion schemes is optimized fresh water production and satisfy internal plant electricity demand The plant freshwater capacity is ∼6000000 m 3 per day. Fusion power plant of this capacity can provide a region of a million populations with fresh water, heat and electricity

Fusion power plant for water desalination and reuse

Energy Technology Data Exchange (ETDEWEB)

Borisov, A.A.; Desjatov, A.V.; Izvolsky, I.M.; Serikov, A.G.; Smirnov, V.P.; Smirnov, Yu.N.; Shatalov, G.E.; Sheludjakov, S.V.; Vasiliev, N.N. E-mail: vasiliev@nfi.kiae.ru; Velikhov, E.P

2001-11-01

Development of industry and agriculture demands a huge fresh water consumption. Exhaust of water sources together with pollution arises a difficult problem of population, industry, and agriculture water supply. Request for additional water supply in next 50 years is expected from industrial and agricultural sectors of many countries in the world. The presented study of fusion power plant for water desalination and reuse is aimed to widen a range of possible fusion industrial applications. Fusion offers a safe, long-term source of energy with abundant resources and major environmental advantages. Thus fusion can provide an attractive energy option to society in the next century. Fusion power tokamak reactor based on RF DEMO-S project [Proc. ISFNT-5 (2000) in press; Conceptual study of RF DEMO-S fusion reactor (2000)] was chosen as an energy source. A steady state operation mode is considered with thermal power of 4.0 GW. The reactor has to operate in steady-state plasma mode with high fraction of bootstrap current. Average plant availability of {approx}0.7 is required. A conventional type of water cooled blanket is the first choice, helium or lithium coolants are under consideration. Desalination plant includes two units: reverse osmosis and distillation. Heat to electricity conversion schemes is optimized fresh water production and satisfy internal plant electricity demand The plant freshwater capacity is {approx}6000000 m{sup 3} per day. Fusion power plant of this capacity can provide a region of a million populations with fresh water, heat and electricity.

LiWall Fusion - The New Concept of Magnetic Fusion

International Nuclear Information System (INIS)

Zakharov, L.E.

2011-01-01

Utilization of the outstanding abilities of a liquid lithium layer in pumping hydrogen isotopes leads to a new approach to magnetic fusion, called the LiWall Fusion. It relies on innovative plasma regimes with low edge density and high temperature. The approach combines fueling the plasma by neutral injection beams with the best possible elimination of outside neutral gas sources, which cools down the plasma edge. Prevention of cooling the plasma edge suppresses the dominant, temperature gradient related turbulence in the core. Such an approach is much more suitable for controlled fusion than the present practice, relying on high heating power for compensating essentially unlimited turbulent energy losses.

High power gyrotrons: a close perspective

International Nuclear Information System (INIS)

Kartikeyan, M.V.

2012-01-01

Gyrotrons and their variants, popularly known as gyrodevices are millimetric wave sources provide very high powers ranging from long pulse to continuous wave (CW) for various technological, scientific and industrial applications. From their conception (monotron-version) in the late fifties until their successful development for various applications, these devices have come a long way technologically and made an irreversible impact on both users and developers. The possible applications of high power millimeter and sub-millimeter waves from gyrotrons and their variants (gyro-devices) span a wide range of technologies. The plasma physics community has already taken advantage of the recent advances of gyrotrons in the areas of RF plasma production, heating, non-inductive current drive, plasma stabilization and active plasma diagnostics for magnetic confinement thermonuclear fusion research, such as lower hybrid current drive (LHCD) (8 GHz), electron cyclotron resonance heating (ECRH) (28-170-220 GHz), electron cyclotron current drive (ECCD), collective Thomson scattering (CTS), heat-wave propagation experiments, and space-power grid (SPG) applications. Other important applications of gyrotrons are electron cyclotron resonance (ECR) discharges for the generation of multi- charged ions and soft X-rays, as well as industrial materials processing and plasma chemistry. Submillimeter wave gyrotrons are employed in high frequency, broadband electron paramagnetic resonance (EPR) spectroscopy. Additional future applications await the development of novel high power gyro-amplifiers and devices for high resolution radar ranging and imaging in atmospheric and planetary science as well as deep space and specialized satellite communications, RF drivers for next generation high gradient linear accelerators (supercolliders), high resolution Doppler radar, radar ranging and imaging in atmospheric and planetary science, drivers for next-generation high-gradient linear accelerators

Blanket options for high-efficiency fusion power

International Nuclear Information System (INIS)

Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

1980-01-01

The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

Fusion blankets for high-efficiency power cycles

International Nuclear Information System (INIS)

Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

1980-01-01

The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

Fusion blanket for high-efficiency power cycles

International Nuclear Information System (INIS)

Usher, J.L.; Powell, J.R.; Fillo, J.A.; Horn, F.L.; Lazareth, O.W.; Taussig, R.

1980-01-01

The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperature (500 0 C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by Ar) utilizing Li 2 O for tritium breeding. In this design, approx. 60% of the fusion energy is deposited in the high-temperature interior. The maximum Ar temperature is 2230 0 C leading to an overall efficiency estimate of 55 to 60% for this reference case

Fusion blankets for high-efficiency power cycles

International Nuclear Information System (INIS)

Usher, J.L.; Lazareth, O.W.; Fillo, J.A.; Horn, F.L.; Powell, J.R.

1981-01-01

The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 deg C) of conventional structural materials such as stainless steels. In this project 'two-zone' blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO 2 interior (cooled by argon) utilizing Li 2 O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230 deg C leading to an overall efficiency estimate of 55 to 60% for this reference case. (author)

Sr-doped Lanthanum Nickelate Nanofibers for High Energy Density Supercapacitors

International Nuclear Information System (INIS)

Cao, Yi; Lin, Baoping; Sun, Ying; Yang, Hong; Zhang, Xueqin

2015-01-01

Highlights: • The electrode made by LNF-0.7 possessed excellent performance (719 F g −1 ) at Na 2 SO 4 electrolyte • LNF-0.7//LNF-0.7 symmetric supercapacitor device were firstly prepared • The maximum energy density of 81.4 Wh·kg −1 are achieved at a power density of 500W·kg −1 • This symmetric supercapacitor also shows an excellent cycling life - Abstract: The series La x Sr 1−x NiO 3−δ (0.3≤x≤1) nanofibers (LNF-x) samples are prepared by using electrospun method. We investigate the structure and the electrochemical properties of LNF-x in detail. As a result, LNF-x nanofibers present a perovskite structure, and the LNF-0.7 sample with high specific surface area display remarkable performance as an electrode material for supercapacitors. The maximum specific capacitance value of 719 F·g −1 at a current density of 2 A·g −1 , which retains 505 F·g −1 at a high current density of 20 A·g −1 , is obtained for LNF-0.7 electrode in 1 M Na 2 SO 4 aqueous electrolyte. Moreover, the LNF-0.7//LNF-0.7 symmetric supercapacitor device using 1 M Na 2 SO 4 aqueous solution is successfully demonstrated. The capacitor device can operate at a cell voltage as high as 2 V, and it exhibits an energy density of 30.5 Wh·kg −1 at a high power density of 10 kW·kg −1 and a high energy density of 81.4 Wh·kg −1 at a low power density of 500 W·kg −1 . More importantly, this symmetric supercapacitor also shows an excellent cycling performance with 90% specific capacitance retention after 2000 charging and discharging cycles. Those results offer a suitable design of electrode materials for high-performance supercapacitors

Characterization of a segmented plasma torch assisted High Heat Flux (HHF) system for performance evaluation of plasma facing components in fusion devices

International Nuclear Information System (INIS)

Ngangom, Aomoa; Sarmah, Trinayan; Sah, Puspa; Kakati, Mayur; Ghosh, Joydeep

2015-01-01

A wide variety of high heat and particle flux test facilities are being used by the fusion community to evaluate the thermal performance of plasma facing materials/components, which includes electron beam, ion beam, neutral beam and thermal plasma assisted sources. In addition to simulate heat loads, plasma sources have the additional advantage of reproducing exact fusion plasma like conditions, in terms of plasma density, temperature and particle flux. At CPP-IPR, Assam, we have developed a high heat and particle flux facility using a DC, non-transferred, segmented thermal plasma torch system, which can produce a constricted, stabilized plasma jet with high ion density. In this system, the plasma torch exhausts into a low pressure chamber containing the materials to be irradiated, which produces an expanded plasma jet with more uniform profiles, compared to plasma torches operated at atmospheric pressure. The heat flux of the plasma beam was studied by using circular calorimeters of different diameters (2 and 3 cm) for different input power (5-55 kW). The effect of the change in gas (argon) flow rate and mixing of gases (argon + hydrogen) was also studied. The heat profile of the plasma beam was also studied by using a pipe calorimeter. From this, the radial heat flux was calculated by using Abel inversion. It is seen that the required heat flux of 10 MW/m 2 is achievable in our system for pure argon plasma as well as for plasma with gas mixtures. The plasma parameters like the temperature, density and the beam velocity were studied by using optical emission spectroscopy. For this, a McPherson made 1.33 meter focal length spectrometer; model number 209, was used. A plane grating with 1800 g/mm was used which gave a spectral resolution of 0.007 nm. A detailed characterization with respect to these plasma parameters for different gas (argon) flow rate and mixing of gases (argon+hydrogen) for different input power will be presented in this paper. The plasma

Migrational polarization in high-current density molten salt electrochemical devices

Energy Technology Data Exchange (ETDEWEB)

Braunstein, J.; Vallet, C.E.

1977-01-01

Electrochemical flux equations based on the thermodynamics of irreversible processes have been derived in terms of experimental transport coefficients for binary molten salt mixtures analogous to those proposed for high temperature batteries and fuel cells. The equations and some numerical solutions indicate steady state composition gradients of significant magnitude. The effects of migrational separation must be considered along with other melt properties in the characterization of electrode behavior, melt composition, operating temperatures and differences of phase stability, wettability and other physicochemical properties at positive and negative electrodes of high current density devices with mixed electrolytes.

Progress in the pulsed power Inertial Confinement Fusion program

International Nuclear Information System (INIS)

Quintenz, J.P.; Matzen, M.K.; Mehlhorn, T.A.

1996-01-01

Pulsed power accelerators are being used in Inertial Confinement Fusion (ICF) research. In order to achieve our goal of a fusion yield in the range of 200 - 1000 MJ from radiation-driven fusion capsules, it is generally believed that ∼10 MJ of driver energy must be deposited within the ICF target in order to deposit ∼1 MJ of radiation energy in the fusion capsule. Pulsed power represents an efficient technology for producing both these energies and these radiation environments in the required short pulses (few tens of ns). Two possible approaches are being developed to utilize pulsed power accelerators in this effort: intense beams of light ions and z- pinches. This paper describes recent progress in both approaches. Over the past several years, experiments have successfully answered many questions critical to ion target design. Increasing the ion beam power and intensity are our next objectives. Last year, the Particle Beam Fusion Accelerator H (PBFA II) was modified to generate ion beams in a geometry that will be required for high yield applications. This 2048 modification has resulted in the production of the highest power ion beam to be accelerated from an extraction ion diode. We are also evaluating fast magnetically-driven implosions (z-pinches) as platforms for ICF ablator physics and EOS experiments. Z-pinch implosions driven by the 20 TW Saturn accelerator have efficiently produced high x- ray power (> 75 TW) and energy (> 400 kJ). Containing these x-ray sources within a hohlraum produces a unique large volume (> 6000 mm 3 ), long lived (>20 ns) radiation environment. In addition to studying fundamental ICF capsule physics, there are several concepts for driving ICF capsules with these x-ray sources. Progress in increasing the x-ray power on the Saturn accelerator and promise of further increases on the higher power PBFA II accelerator will be described

The reversed-field pinch: a compact approach to fusion power

International Nuclear Information System (INIS)

Hagenson, R.L.; Krakowski, R.A.; Bathke, C.G.; Miller, R.L.

1985-01-01

The potential of the reversed-field pinch (RFP) for development into an efficient, compact, copper-coil fusion reactor has been quantified by comprehensive parametric tradeoff studies. This compact system promises to be competitive in size, power density, and cost to alternative energy sources. Conceptual engineering designs that substantiate these promising results have been completed. This 1000 MW(e) (net) design is described along with a detailed rationale and physics/technology assessment for the compact approach to fusion. The RFP presents a robust plasma confinement system capable of providing a range of reactor systems that are compact in both physical size and/or net power output while ensuring acceptable cost and engineering feasibility for a range of assumed physics performance. (author)

Inertial confinement fusion

International Nuclear Information System (INIS)

Nuckolls, J.H.; Wood, L.L.

1988-01-01

Edward Teller has been a strong proponent of harnessing nuclear explosions for peaceful purposes. There are two approaches: Plowshare, which utilizes macro- explosions, and inertial confinement fusion, which utilizes microexplosions. The development of practical fusion power plants is a principal goal of the inertial program. It is remarkable that Teller's original thermonuclear problem, how to make super high yield nuclear explosions, and the opposite problem, how to make ultra low yield nuclear explosions, may both be solved by Teller's radiation implosion scheme. This paper reports on the essential physics of these two thermonuclear domains, which are separated by nine orders of magnitude in yield, provided by Teller's similarity theorem and its exceptions. Higher density makes possible thermonuclear burn of smaller masses of fuel. The leverage is high: the scale of the explosion diminishes with the square of the increase in density. The extraordinary compressibility of matter, first noticed by Teller during the Los Alamos atomic bomb program, provides an almost incredible opportunity to harness fusion. The energy density of thermonuclear fuels isentropically compressed to super high-- -densities---even to ten thousand times solid density---is small compared to the energy density at thermonuclear ignition temperatures. In small masses of fuel imploded to these super high matter densities, the energy required to achieve ignition may be greatly reduced by exploiting thermonuclear propagation from a relatively small hot spot

Diagnostics Development towards Steady State Operation in Fusion Devices

Energy Technology Data Exchange (ETDEWEB)

Burhenn, R.; Baldzuhn, J.; Dreier, H.; Endler, M.; Hartfuss, H.J.; Hildebrandt, D.; Hirsch, M.; Koenig, R.; Kornejev, P.; Krychowiak, M.; Laqua, H.P.; Laux, M.; Oosterbeek, J.W.; Pasch, E.; Schneider, W.; Thomsen, H.; Weller, A.; Werner, A.; Wolf, R.; Zhang, D. [Max-Planck-Institute fuer Plasmaphysik, EURATOM Association, D-17491 Greifswald (Germany); Biel, W. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich GmbH EURATOM Association, Trilateral Euregio Cluster, D-52425 Juelich (Germany)

2011-07-01

The stellarator Wendelstein 7-X (W7-X) is being presently under construction and is already equipped with superconducting coil systems and principally is capable of quasi-continuous operation. However, W7-X is faced with new enhanced technical requirements which have to be met by plasma facing components as well as the diagnostic systems in general. Depending on the available heating power, the continuous heat flux to plasma facing components during long pulse operation might lead to unacceptable local thermal overload and necessitates sufficient but often complicate active cooling precautions. Fusion devices with electron cyclotron frequency heating (ECRH) are concerned with significant stray radiation, depending on the chosen heating scheme and the plasma parameters. The required shielding is often not compatible with optimal UHV-consistent design and high intensity throughput. For machine safety, diagnostics are required which are able to identify enhanced plasma wall interaction on a fast time scale in order to prevent damage in time. For W7-X, video camera systems covering most of the inner wall, fast IR-camera systems with coating-resistant pinhole-optics for the observation of the divertor surface temperature and spectrometers with large spectral survey covering relevant spectral lines of all intrinsic impurities with sufficient spectral resolution and sensitivity are necessary. In combination with energy integrating but spatially resolving diagnostics like bolometers and soft-X cameras slow impurity accumulation phenomena on a time scale much larger than flat-top times typically achieved in short-pulse operation can be identified and a radiative plasma collapse possibly be avoided by counteractive measures. Longer port dimensions due to thermal insulation of the cryogenic coil system and high density operation with strong density gradients necessitate the choice of shorter wavelengths for interferometer laser beams. This complicates the avoidance of fringe

ICC Experiment Performance Improvement through Advanced Feedback Controllers for High-Power Low-Cost Switching Power Amplifiers

International Nuclear Information System (INIS)

Nelson, Brian A.

2006-01-01

Limited resources force most smaller fusion energy research experiments to have little or no feedback control of their operational parameters, preventing achievement of their full operational potential. Recent breakthroughs in high-power switching technologies have greatly reduced feedback-controlled power supply costs, primarily those classified as switching power amplifiers. However, inexpensive and flexible controllers for these power supplies have not been developed. A uClinux-based micro-controller (Analog Devices Blackfin BF537) was identified as having the capabilities to form the base of a digital control system for switching power amplifiers. A control algorithm was created, and a Linux character device driver was written to realize the algorithm. The software and algorithm were successfully tested on a switching power amplifier and magnetic field coil using University of Washington (subcontractor) resources

Fusion power core engineering for the ARIES-ST power plant

International Nuclear Information System (INIS)

Tillack, M.S.; Wang, X.R.; Pulsifer, J.; Malang, S.; Sze, D.K.; Billone, M.; Sviatoslavsky, I.

2003-01-01

ARIES-ST is a 1000 MWe fusion power plant based on a low aspect ratio 'spherical torus' (ST) plasma. The ARIES-ST power core was designed to accommodate the unique features of an ST power plant, to meet the top-level requirements of an attractive fusion energy source, and to minimize extrapolation from the fusion technology database under development throughout the world. The result is an advanced helium-cooled ferritic steel blanket with flowing PbLi breeder and tungsten plasma-interactive components. Design improvements, such as the use of SiC inserts in the blanket to extend the outlet coolant temperature range were explored and the results are reported here. In the final design point, the power and particle loads found in ARIES-ST are relatively similar to other advanced tokamak power plants (e.g. ARIES-RS [Fusion Eng. Des. 38 (1997) 3; Fusion Eng. Des. 38 (1997) 87]) such that exotic technologies were not required in order to satisfy all of the design criteria. Najmabadi and the ARIES Team [Fusion Eng. Des. (this issue)] provide an overview of ARIES-ST design. In this article, the details of the power core design are presented together with analysis of the thermal-hydraulic, thermomechanical and materials behavior of in-vessel components. Detailed engineering analysis of ARIES-ST TF and PF systems, nuclear analysis, and safety are given in the companion papers

Power source system for nuclear fusion

International Nuclear Information System (INIS)

Nakagawa, Satoshi.

1975-01-01

Object: When using an external system power source and an exclusive power source in a power source circuit for supplying power to the coils of a nuclear fusion apparatus, to minimize the capacity of the exclusive power source and provide an economical power source circuit construction. Structure: In the initial stage of the power supply, rectifying means provided in individual blocks are connected in parallel on the AC side, and power is supplied to the coils of the nuclear fusion apparatus from an external system power source with the exclusive power source held in the disconnected state. Further, at an instant when the limit of permissible input is reached, the afore-mentioned parallel circuit consisting of rectifying means is disconnected, while at the same time the exclusive power source is connected to the input side of the rectifying means provided in a block corresponding to the exclusive power source side, thereby supplying power to the coils of the nuclear fusion apparatus from both the external system power source and exclusive power source. (Kamimura, M.)

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...

Room-temperature vertically-aligned copper oxide nanoblades synthesized by electrochemical restructuring of copper hydroxide nanorods: An electrode for high energy density hybrid device

Science.gov (United States)

Zhang, Xuetao; Zhou, Jinyuan; Dou, Wei; Wang, Junya; Mu, Xuemei; Zhang, Yue; Abas, Asim; Su, Qing; Lan, Wei; Xie, Erqing; Zhang, Chuanfang (John)

2018-04-01

The fast growing of portable electronics has greatly stimulated the development of energy storage materials, such as transition metal oxides (TMOs). However, TMOs usually involve harsh synthesis conditions, such as high temperature. Here we take advantage of the metastable nature of Cu(OH)2 and grow CuO nanoblades (NBs) on Cu foam under the electric field at room temperature. The electrochemical polarization accelerates the dissolution of Cu(OH)2 nanorods, guides the deposition of the as-dissolved Cu(OH)42- species and eventually leads to the phase transformation of CuO NBs. The unique materials architecture render the vertically-aligned CuO NBs with enhanced electronic and ionic diffusion kinetics, high charge storage (∼779 mC cm-2 at 1 mA cm-2), excellent rate capability and long-term cycling performances. Further matching with activated carbon electrode results in high-performance hybrid device, which displays a wide voltage window (1.7 V) in aqueous electrolyte, high energy density (0.17 mWh cm-2) and power density (34 mW cm-2) coupled with long lifetime, surpassing the best CuO based device known. The hybrid device can be randomly connected and power several light-emitting diodes. Importantly, such an electrochemical restructuring approach is cost-effective, environmentally green and universal, and can be extended to synthesize other metastable hydroxides to in-situ grow corresponding oxides.

ICAN: High power neutral beam generation

International Nuclear Information System (INIS)

Moustaizis, S.D.; Lalousis, P.; Perrakis, K.; Auvray, P.; Larour, J.; Ducret, J.E.; Balcou, P.

2015-01-01

During the last few years there is an increasing interest on the development of alternative high power new negative ion source for Tokamak applications. The proposed new neutral beam device presents a number of advantages with respect to: the density current, the acceleration voltage, the relative compact dimension of the negative ion source, and the coupling of a high power laser beam for photo-neutralization of the negative ion beam. Here we numerically investigate, using a multi- fluid 1-D code, the acceleration and the extraction of high power ion beam from a Magnetically Insulated Diode (MID). The diode configuration will be coupled to a high power device capable of extracting a current up to a few kA with an accelerating voltage up to MeV. An efficiency of up to 92% of the coupling of the laser beam, is required in order to obtain a high power, up to GW, neutral beam. The new high energy, high average power, high efficiency (up to 30%) ICAN fiber laser is proposed for both the plasma generation and the photo-neutralizer configuration. (authors)

Pulsed power for angular multiplexed laser fusion drivers

International Nuclear Information System (INIS)

Eninger, J.E.

1983-01-01

The feasibility of using rare gas-halide lasers, in particular the KrF laser, as inertial confinement fusion (ICF) drivers has been assessed. These lasers are scalable to the required high energy (approx. =1-5 MJ) in a short pulse (approx. =10 ns) by optical angular multiplexing, and integration of the output from approx. =100 kJ laser amplifier subsystems. The e-beam current density (approx. =50A/cm 2 ) and voltage (approx. =800 kV) required for these power amplifiers lead to an e-beam impedance of approx. =0.2Ω for approx. =300 ns pump time. This impedance level requires modularization of the large area e-gun, a) to achieve a diode inductance consistent with fast current risetime, b) to circumvent dielectric breakdown constraints in the pulse forming lines, and c) to reduce the requirement for guide magnetic fields. Pulsed power systems requirements, design concepts, scalability, tradeoffs, and performance projections are discussed in this paper

Fusion Engineering Device. Volume II. Design description

International Nuclear Information System (INIS)

1981-10-01

This volume summarizes the design of the FED. It includes a description of the major systems and subsystems, the supporting plasma design analysis, a projected device cost and associated construction schedule, and a description of the facilities to house and support the device. This effort represents the culmination of the FY81 studies conducted at the Fusion Engineering Design Center (FEDC). Unique in these design activities has been the collaborative involvement of the Design Center personnel and numerous resource physicists from the fusion community who have made significant contributions in the physics design analysis as well as the physics support of the engineering design of the major FED systems and components

Spatial heterogeneity of tungsten transmutation in a fusion device

Science.gov (United States)

Gilbert, M. R.; Sublet, J.-Ch.; Dudarev, S. L.

2017-04-01

Accurately quantifying the transmutation rate of tungsten (W) under neutron irradiation is a necessary requirement in the assessment of its performance as an armour material in a fusion power plant. The usual approach of calculating average responses, assuming large, homogenised material volumes, is insufficient to capture the full complexity of the transmutation picture in the context of a realistic fusion power plant design, particularly for rhenium (Re) production from W. Combined neutron transport and inventory simulations for representative spatially heterogeneous high-resolution models of a fusion power plant show that the production rate of Re is strongly influenced by the surrounding local spatial environment. Localised variation in neutron moderation (slowing down) due to structural steel and coolant, particularly water, can dramatically increase Re production because of the huge cross sections of giant resolved resonances in the neutron-capture reaction of 186W at low neutron energies. Calculations using cross section data corrected for temperature (Doppler) effects suggest that temperature may have a relatively lesser influence on transmutation rates.

High power density reactors based on direct cooled particle beds

Science.gov (United States)

Powell, J. R.; Horn, F. L.

Reactors based on direct cooled High Temperature Gas Cooled Reactor (HTGR) type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out along the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBRs) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed.

AxiaLIF system: minimally invasive device for presacral lumbar interbody spinal fusion

Directory of Open Access Journals (Sweden)

Rapp SM

2011-08-01

Full Text Available Steven M Rapp1, Larry E Miller2,3, Jon E Block31Michigan Spine Institute, Waterford, MI, USA; 2Miller Scientific Consulting Inc, Biltmore Lake, NC, USA; 3Jon E. Block, Ph.D., Inc., San Francisco, CA, USAAbstract: Lumbar fusion is commonly performed to alleviate chronic low back and leg pain secondary to disc degeneration, spondylolisthesis with or without concomitant lumbar spinal stenosis, or chronic lumbar instability. However, the risk of iatrogenic injury during traditional anterior, posterior, and transforaminal open fusion surgery is significant. The axial lumbar interbody fusion (AxiaLIF system is a minimally invasive fusion device that accesses the lumbar (L4–S1 intervertebral disc spaces via a reproducible presacral approach that avoids critical neurovascular and musculoligamentous structures. Since the AxiaLIF system received marketing clearance from the US Food and Drug Administration in 2004, clinical studies of this device have reported high fusion rates without implant subsidence, significant improvements in pain and function, and low complication rates. This paper describes the design and approach of this lumbar fusion system, details the indications for use, and summarizes the clinical experience with the AxiaLIF system to date.Keywords: AxiaLIF, fusion, lumbar, minimally invasive, presacral

A proposal of nuclear fusion power plant equipped with SMES

International Nuclear Information System (INIS)

Natsukawa, Tatsuya; Makamura, Hirokazu; Molinas, Marta; Nomura, Shinichi; Tsuji-Iio, Shunji; Shimada, Ryuichi

2000-01-01

When we intend to operate the nuclear fusion power plant (NFPP) under the economically efficient conditions as an independent power plant, it is desirable that the generated electric power should be sent to network according to the power demand. With such strategy being expanded, some energy storage system is available. In this paper, NFPP equipped with the superconducting magnetic energy storage system (SMES) as electric power storage device is proposed. The advantages of NFPP equipped with SMES are discussed and a case study of 500 MW NFPP equipped with 6 GWh SMES is done with estimating its operational value. For SMES coil, the concept of Force Balanced Coil (FBC) is applied and 6 GWh class FBC is briefly designed

Integrative Multi-Spectral Sensor Device for Far-Infrared and Visible Light Fusion

Science.gov (United States)

Qiao, Tiezhu; Chen, Lulu; Pang, Yusong; Yan, Gaowei

2018-06-01

Infrared and visible light image fusion technology is a hot spot in the research of multi-sensor fusion technology in recent years. Existing infrared and visible light fusion technologies need to register before fusion because of using two cameras. However, the application effect of the registration technology has yet to be improved. Hence, a novel integrative multi-spectral sensor device is proposed for infrared and visible light fusion, and by using the beam splitter prism, the coaxial light incident from the same lens is projected to the infrared charge coupled device (CCD) and visible light CCD, respectively. In this paper, the imaging mechanism of the proposed sensor device is studied with the process of the signals acquisition and fusion. The simulation experiment, which involves the entire process of the optic system, signal acquisition, and signal fusion, is constructed based on imaging effect model. Additionally, the quality evaluation index is adopted to analyze the simulation result. The experimental results demonstrate that the proposed sensor device is effective and feasible.

LTCC magnetic components for high density power converter

Science.gov (United States)

Lebourgeois, Richard; Labouré, Eric; Lembeye, Yves; Ferrieux, Jean-Paul

2018-04-01

This paper deals with multilayer magnetic components for power electronics application and specifically for high frequency switching. New formulations based on nickel-zinc-copper spinel ferrites were developed for high power and high frequency applications. These ferrites can be sintered at low temperature (around 900°C) which makes them compatible with the LTCC (Low Temperature Co-fired Ceramics) technology. Metallic parts of silver or gold can be fully integrated inside the ferrite while guaranteeing the integrity of both the ferrite and the metal. To make inductors or transformers with the required properties, it is mandatory to have nonmagnetic parts between the turns of the winding. Then it is essential to find a dielectric material, which can be co-sintered both with the ferrite and the metal. We will present the solution we found to this problem and we will describe the results we obtained for a multilayer co-sintered transformer. We will see that these new components have good performance compared with the state of the art and are very promising for developing high density switching mode power supplies.

From Swords to Plowshares: The US/Russian Collaboration in High Energy Density Physics Using Pulsed Power

International Nuclear Information System (INIS)

Younger, S.M.; Fowler, C.M.; Lindemuth, I.; Chernyshev, V.K.; Mokhov, V.N.; Pavlovskii, A.I.

1999-01-01

Since 1992, the All-Russian Scientific Research Institute of Experimental Physics and the Los Alamos National Laboratory, the institutes that designed the first nuclear weapons of the Soviet Union and the US, respectively, have been working together in fundamental research related to pulsed power and high energy density science. This collaboration has enabled scientists formerly engaged in weapons activities to redirect their attention to peaceful pursuits of wide benefit to the technical community. More than thirty joint experiments have been performed at Sarov and Los Alamos in areas as diverse as solid state physics in high magnetic fields, fusion plasma formation, isentropic compression of noble gases, and explosively driven-high current generation technology. Expanding on the introductory comments of the conference plenary presentation, this paper traces the origins of this collaboration and briefly reviews the scientific accomplishments. Detailed reports of the scientific accomplishments can be found in other papers in these proceedings and in other publications

Power source device for thermonuclear device

International Nuclear Information System (INIS)

Ozaki, Akira.

1992-01-01

The present invention provides a small sized and economical power source device for a thermonuclear device. That is, the device comprises a conversion device having a rated power determined by a power required during a plasma current excitation period and a conversion device having a rated power determined by a power required during a plasma current maintaining period, connected in series to each other. Then, for the former conversion device, power is supplied from an electric power generator and, for the latter, power is supplied from a power system. With such a constitution, during the plasma electric current maintaining period for substantially continuous operation, it is possible to conduct bypassing paired operation for the former conversion device while the electric power generator is put under no load. Further, since a short period rated power may be suffice for the former conversion device and the electric power generator having the great rated power required for the plasma electric current excitation period, they can be reduced in the size and made economical. On the other hand, since the power required for the plasma current maintaining period is relatively small, the capacity of the continuous rated conversion device may be small, and the power can be received from the power system. (I.S.)

Nuclear engineering questions: power, reprocessing, waste, decontamination, fusion

International Nuclear Information System (INIS)

Walton, R.D. Jr.

1979-01-01

This volume contains papers presented at the chemical engineering symposium on nuclear questions. Specific questions addressed by the speakers included: nuclear power - why and how; commercial reprocessing - permanent death or resurrection; long-term management of commercial high-level wastes; long-term management of defense high-level waste; decontamination and decommissioning of nuclear facilities, engineering aspects of laser fusion I; and engineering aspects of laser fusion II. Individual papers have been input to the Energy Data Base previously

Large power supply facilities for fusion research

International Nuclear Information System (INIS)

Miyahara, Akira; Yamamoto, Mitsuyoshi.

1976-01-01

The authors had opportunities to manufacture and to operate two power supply facilities, that is, 125MVA computer controlled AC generator with a fly wheel for JIPP-T-2 stellerator in Institute of Plasma Physics, Nagoya University and 3MW trial superconductive homopolar DC generator to the Japan Society for Promotion of Machine Industry. The 125MVA fly-wheel generator can feed both 60MW (6kV x 10kA) DC power for toroidal coils and 20MW (0.5kV x 40kA) DC power for helical coils. The characteristic features are possibility of Bung-Bung control based on Pontrjagin's maximum principle, constant current control or constant voltage control for load coils, and cpu control for routine operation. The 3MW (150V-20000A) homopolar generator is the largest in the world as superconductive one, however, this capacity is not enough for nuclear fusion research. The problems of power supply facilities for large Tokamak devices are discussed

High power density reactors based on direct cooled particle beds

International Nuclear Information System (INIS)

Powell, J.R.; Horn, F.L.

1985-01-01

Reactors based on direct cooled HTGR type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out long the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBR's) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed. 12 figs

NASA Glenn Research Center Program in High Power Density Motors for Aeropropulsion

Science.gov (United States)

Brown, Gerald V.; Kascak, Albert F.; Ebihara, Ben; Johnson, Dexter; Choi, Benjamin; Siebert, Mark; Buccieri, Carl

2005-01-01

Electric drive of transport-sized aircraft propulsors, with electric power generated by fuel cells or turbo-generators, will require electric motors with much higher power density than conventional room-temperature machines. Cryogenic cooling of the motor windings by the liquid hydrogen fuel offers a possible solution, enabling motors with higher power density than turbine engines. Some context on weights of various systems, which is required to assess the problem, is presented. This context includes a survey of turbine engine weights over a considerable size range, a correlation of gear box weights and some examples of conventional and advanced electric motor weights. The NASA Glenn Research Center program for high power density motors is outlined and some technical results to date are presented. These results include current densities of 5,000 A per square centimeter current density achieved in cryogenic coils, finite element predictions compared to measurements of torque production in a switched reluctance motor, and initial tests of a cryogenic switched reluctance motor.

Nonlinear dielectric thin films for high-power electric storage with energy density comparable with electrochemical supercapacitors.

Science.gov (United States)

Yao, Kui; Chen, Shuting; Rahimabady, Mojtaba; Mirshekarloo, Meysam Sharifzadeh; Yu, Shuhui; Tay, Francis Eng Hock; Sritharan, Thirumany; Lu, Li

2011-09-01

Although batteries possess high energy storage density, their output power is limited by the slow movement of charge carriers, and thus capacitors are often required to deliver high power output. Dielectric capacitors have high power density with fast discharge rate, but their energy density is typically much lower than electrochemical supercapacitors. Increasing the energy density of dielectric materials is highly desired to extend their applications in many emerging power system applications. In this paper, we review the mechanisms and major characteristics of electric energy storage with electrochemical supercapacitors and dielectric capacitors. Three types of in-house-produced ferroic nonlinear dielectric thin film materials with high energy density are described, including (Pb(0.97)La(0.02))(Zr(0.90)Sn(0.05)Ti(0.05))O(3) (PLZST) antiferroelectric ceramic thin films, Pb(Zn(1/3)Nb(2/3))O(3-)Pb(Mg(1/3)Nb(2/3))O(3-)PbTiO(3) (PZN-PMN-PT) relaxor ferroelectric ceramic thin films, and poly(vinylidene fluoride) (PVDF)-based polymer blend thin films. The results showed that these thin film materials are promising for electric storage with outstandingly high power density and fairly high energy density, comparable with electrochemical supercapacitors.

High speed and high functional inverter power supplies for plasma generation and control, and their performance

International Nuclear Information System (INIS)

Uesugi, Yoshihiko; Razzak, Mohammad A.; Kondo, Kenji; Kikuchi, Yusuke; Takamura, Shuichi; Imai, Takahiro; Toyoda, Mitsuhiro

2003-01-01

The Rapid development of high power and high speed semiconductor switching devices has led to their various applications in related plasma fields. Especially, a high speed inverter power supply can be used as an RF power source instead of conventional linear amplifiers and a power supply to control the magnetic field in a fusion plasma device. In this paper, RF thermal plasma production and plasma heating experiments are described emphasis placed on using a static induction transistor inverter at a frequency range between 200 kHz and 2.5 MHz as an RF power supply. Efficient thermal plasma production is achieved experimentally by using a flexible and easily operated high power semiconductor inverter power supply. Insulated gate bipolar transistor (IGBT) inverter power supplies driven by a high speed digital signal processor are applied as tokamak joule coil and vertical coil power supplies to control plasma current waveform and plasma equilibrium. Output characteristics, such as the arbitrary bipolar waveform generation of a pulse width modulation (PWM) inverter using digital signal processor (DSP) can be successfully applied to tokamak power supplies for flexible plasma current operation and fast position control of a small tokamak. (author)

The Role of Electrode Contamination and the Effects of Cleaning and Conditioning on the Performance of High-Energy, Pulsed-Power Devices

Energy Technology Data Exchange (ETDEWEB)

Cuneo, M.E.

1998-11-10

High-energy pulsed-power devices routinely access field strengths above those at which broad-area, cathode-initiated, high-voltage vacuum-breakdown occur. Examples include magnetically-insulated-transmission lines and current convolutes, high-current-density electron and ion diodes, high-power microwave devices, and cavities and other structures for electrostatic and RF accelerators. Energy deposited in anode surfaces may exceed anode plasma thermal-desorption creation thresholds on the time-scale of the pulse. Stimulated resorption by electron or photon bombardment can also lead to plasma formation on electrode or insulator surfaces. Device performance is limited above these thresholds, particularly impulse length and energy, by the formation and expansion of neutral and plasma layers formed, primarily from electrode contaminants. In-situ conditioning tech&ques to modify and eliminate the contaminants through multiple high-voltage pukes, low base pressures, RF discharge cleaning, heating, surface coatings, and ion- and electron-beam surface treatment allow access to new regimes of performance through control of plasma formation and modification of the plasma properties. Experimental and theoretical progress from a variety of devices and small scale experiments with a variety of treatment methods will be reviewed and recommendations given for future work.

TASKA-M - a low cost, near term tandem mirror device for fusion technology testing

International Nuclear Information System (INIS)

Badger, B.; Corradini, M.L.; El-Guebaly, L.; Emmert, G.A.; Kulcinski, G.L.; Larsen, E.M.; Maynard, C.W.; Perkins, L.J.; Peterson, R.R.; Plute, K.E.; Santarius, J.F.; Sawan, M.E.; Scharer, J.E.; Sviatoslavsky, I.N.; Sze, D.K.; Vogelsang, W.F.; Wittenberg, L.J.; Leppelmeier, G.W.; Grover, J.M.; Opperman, E.K.; Vogel, M.A.; Borie, E.; Taczanowski, S.; Arendt, F.; Dittrich, H.G.; Fett, T.; Haferkamp, B.; Heinz, W.; Hoelzchen, E.; Kleefeldt, K.; Klingelhoefer, R.; Komarek, P.; Kuntze, M.; Leiste, H.G.; Link, W.; Malang, S.; Manes, B.M.; Maurer, W.; Michael, I.; Mueller, R.A.; Neffe, G.; Schramm, K.; Suppan, A.; Weinberg, D.

1984-04-01

TASKA-M (Modifizierte Tandem Spiegelmaschine Karlsruhe) is a study of a dedicated fusion technology device based on the mirror principle, in continuation of the 1981/82 TASKA study. The main objective is to minimize cost while retaining key requirements of neutron flux and fluence for blanket and material development and for component testing in a nuclear environment. Direct costs are reduced to about 400 M$ by dropping reactor-relevant aspects not essential to technology testing: No thermal barrier and electrostatic plugging of the plasma; fusion power of 7 MW at an injected power of 44 MW; tritium supply from external sources. All technologies for operating the machine are expected to be available by 1990; the plasma physics relies on microstabilization in a sloshing ion population. (orig.) [de

Perspectives of fusion power

International Nuclear Information System (INIS)

Jensen, V.O.

1984-01-01

New and practically inexhaustible sources of energy must be developed for the period when oil, coal and uranium will become scarce and expensive. Nuclear fusion holds great promise as one of these practically inexhaustible energy sources. Based on the deuteriumtritium reaction with tritium obtained from naturally occuring lithium, which is also widely available in Europe, the accessible energy resources in the world are 3.10 12 to 3.10 16 toe; based on the deuterium-deuterium reaction, the deuterium content of the oceans corresponds to 10 20 toe. It is presently envisaged that in order to establish fusion as a large-scale energy source, three major thresholds must be reached: - Scientific feasibility, - Technical feasibility, i.e. the proof that the basic technical problems of the fusion reactor can be solved. - Commercial feasibility, i.e. proof that fusion power reactors can be built on an industrial scale, can be operated reliably and produce usable energy at prices competitive with other energy sources. From the above it is clear that the route to commercial fusion will be long and costly and involve the solution of extremely difficult technical problems. In view of the many steps which have to be taken, it appears unlikely that commercial fusion power will be in general use within the next 50 years and by that time world-wide expenditure on research, development and demonstration may well have exceeded 100 Bio ECU. (author)

Developmental validation of the PowerPlex(®) Fusion 6C System.

Science.gov (United States)

Ensenberger, Martin G; Lenz, Kristy A; Matthies, Learden K; Hadinoto, Gregory M; Schienman, John E; Przech, Angela J; Morganti, Michael W; Renstrom, Daniel T; Baker, Victoria M; Gawrys, Kori M; Hoogendoorn, Marlijn; Steffen, Carolyn R; Martín, Pablo; Alonso, Antonio; Olson, Hope R; Sprecher, Cynthia J; Storts, Douglas R

2016-03-01

The PowerPlex(®) Fusion 6C System is a 27-locus, six-dye, multiplex that includes all markers in the expanded CODIS core loci and increases overlap with STR database standards throughout the world. Additionally, it contains two, rapidly mutating, Y-STRs and is capable of both casework and database workflows, including direct amplification. A multi-laboratory developmental validation study was performed on the PowerPlex(®) Fusion 6C System. Here, we report the results of that study which followed SWGDAM guidelines and includes data for: species specificity, sensitivity, stability, precision, reproducibility and repeatability, case-type samples, concordance, stutter, DNA mixtures, and PCR-based procedures. Where appropriate we report data from both extracted DNA samples and direct amplification samples from various substrates and collection devices. Samples from all studies were separated on both Applied Biosystems 3500 series and 6-dye capable 3130 series Genetic Analyzers and data is reported for each. Together, the data validate the design and demonstrate the performance of the PowerPlex(®) Fusion 6C System. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Development of a current-type PWM converter with high power factor. 1

International Nuclear Information System (INIS)

Miura, Yushi; Matsukawa, Makoto; Miyachi, Kengo; Kimura, Toyoaki

1998-01-01

A power supply system for superconducting poloidal field coils of a next generation tokamak-type fusion device can be operated on the relatively low voltage for the duration of discharge except the plasma initiation. In the case of the conventional phase-controlled thyristor converters are adopted in such a system, the input power factor would be low in average, and a reactive power fluctuation caused by the change of DC output voltage may produce serious effects on the commercial transmission line. From the above viewpoint, a current-type PWM (Pulse Width Modulation) converter, which can work with the power factor of unity for the input power, is regarded as one of the promising candidates of the converters for the power supplies of next generation fusion devices. Hence, a 100kW-class current-type PWM converter has been developed by using IGBT (Insulated Gate Bipolar Transistor) as switching devices. In this development, the basic performance has been preliminary investigated whether this converter is applicable to the power supply for the next generation fusion device. In addition, two different PWM control methods were examined whether these methods can realize a unit power factor and suppress the transient oscillation of converter input current at the same time in case that the reference of DC output current is changed rapidly. (author)

HYFIRE: fusion-high temperature electrolysis system

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Dang, V.D.; Horn, F.; Isaacs, H.; Lazareth, O.; Makowitz, H.; Usher, J.

1980-01-01

The Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constitutents, H 2 and O 2 , electrical input is required. Power cycle efficiencies of approx. 40% require He cooling for steam superheat. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices

Science.gov (United States)

Gamzina, Diana

Diana Gamzina March 2016 Mechanical and Aerospace Engineering Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices Abstract A methodology for performing thermo-mechanical design and analysis of high frequency and high average power vacuum electron devices is presented. This methodology results in a "first-pass" engineering design directly ready for manufacturing. The methodology includes establishment of thermal and mechanical boundary conditions, evaluation of convective film heat transfer coefficients, identification of material options, evaluation of temperature and stress field distributions, assessment of microscale effects on the stress state of the material, and fatigue analysis. The feature size of vacuum electron devices operating in the high frequency regime of 100 GHz to 1 THz is comparable to the microstructure of the materials employed for their fabrication. As a result, the thermo-mechanical performance of a device is affected by the local material microstructure. Such multiscale effects on the stress state are considered in the range of scales from about 10 microns up to a few millimeters. The design and analysis methodology is demonstrated on three separate microwave devices: a 95 GHz 10 kW cw sheet beam klystron, a 263 GHz 50 W long pulse wide-bandwidth sheet beam travelling wave tube, and a 346 GHz 1 W cw backward wave oscillator.

Reactor power control device

International Nuclear Information System (INIS)

Doi, Kazuyori.

1981-01-01

Purpose: To automatically control the BWR type reactor power by simple and short-time searching the load pattern nearest to the required pattern at a nuclear power plant side. Constitution: The reactor power is automatically regulated by periodical modifying of coefficients fitting to a reactor core model, according as a required load pattern. When a load requirement pattern is given, a simulator estimates the total power change and the axial power distribution change from a xenon density change output calculated by a xenon dynamic characteristic estimating device, and a load pattern capable of being realized is searched. The amount to be recirculated is controlled on the basis of the load patteren thus searched, and the operation of the BWR type reactor is automatically controlled at the side of the nuclear power plant. (Kamimura, M.)

Net energy balance of tokamak fusion power plants

International Nuclear Information System (INIS)

Buende, R.

1983-01-01

The net energy balance for a tokamak fusion power plant of present day design is determined by using a PWR power plant as reference system, replacing the fission-specific components by fusion-specific components and adjusting the non-reactor-specific components to altered conditions. For determining the energy input to the fusion plant a method was developed that combines the advantages of the energetic input-output method with those of process chain analysis. A comparison with PWR, HTR, FBR, and coal-fired power plants is made. As a result the energy expenditures of the fusion power plant turn out to be lower than that of an LWR, HTR, or coal-fired power plant of equal net electric power output and nearly in the same range as FBR power plants. (orig.)

Net energy balance of tokamak fusion power plants

International Nuclear Information System (INIS)

Buende, R.

1981-10-01

The net energy balance for a tokamak fusion power plant was determined by using a PWR power plant as reference system, replacing the fission-specific components by fusion-specific components and adjusting the non-reactor-specific components to altered conditions. For determining the energy input to the fusion plant a method was developed that combines the advantages of the energetic input-output method with those of process chain analysis. A comparison with PWR, HTR, FBR, and coal-fired power plants is made. As a result the net energy balance of the fusion power plant turns out to be more advantageous than that of an LWR, HTR or coal-fired power plant and nearly in the same range as FBR power plants. (orig.)

Electron beam gun with kinematic coupling for high power RF vacuum devices

Science.gov (United States)

Borchard, Philipp

2016-11-22

An electron beam gun for a high power RF vacuum device has components joined by a fixed kinematic coupling to provide both precise alignment and high voltage electrical insulation of the components. The kinematic coupling has high strength ceramic elements directly bonded to one or more non-ductile rigid metal components using a high temperature active metal brazing alloy. The ceramic elements have a convex surface that mates with concave grooves in another one of the components. The kinematic coupling, for example, may join a cathode assembly and/or a beam shaping focus electrode to a gun stem, which is preferably composed of ceramic. The electron beam gun may be part of a high power RF vacuum device such as, for example, a gyrotron, klystron, or magnetron.

Hybrid fission-fusion nuclear reactors

International Nuclear Information System (INIS)

Zucchetti, Massimo

2011-01-01

A fusion-fission hybrid could contribute to all components of nuclear power - fuel supply, electricity production, and waste management. The idea of the fusion-fission hybrid is many decades old. Several ideas, both new and revisited, have been investigated by hybrid proponents. These ideas appear to have attractive features, but they require various levels of advances in plasma science and fusion and nuclear technology. As a first step towards the development of hybrid reactors, fusion neutron sources can be considered as an option. Compact high-field tokamaks can be a candidate for being the neutron source in a fission-fusion hybrid, essentially due to their design characteristics, such as compact dimensions, high magnetic field, flexibility of operation. This study presents the development of a tokamak neutron source for a material testing facility using an Ignitor-based concept. The computed values show the potential of this neutron-rich device for fusion materials testing. Some full-power months of operation are sufficient to obtain relevant radiation damage values in terms of dpa. (Author)

Current fusion power plant design concepts

International Nuclear Information System (INIS)

Gore, B.F.; Murphy, E.S.

1976-09-01

Nine current U.S. designs for fusion power plants are described in this document. Summary tabulations include a tenth concept, for which the design document was unavailable during preparation of the descriptions. The information contained in the descriptions was used to define an envelope of fusion power plant characteristics which formed the basis for definition of reference first commercial fusion power plant design. A brief prose summary of primary plant features introduces each of the descriptions contained in the body of this document. In addition, summary tables are presented. These tables summarize in side-by-side fashion, plant parameters, processes, combinations of materials used, requirements for construction materials, requirements for replacement materials during operation, and production of wastes

Data-Acquisition Systems for Fusion Devices

NARCIS (Netherlands)

van Haren, P. C.; Oomens, N. A.

1993-01-01

During the last two decades, computerized data acquisition systems (DASs) have been applied at magnetic confinement fusion devices. Present-day data acquisition is done by means of distributed computer systems and transient recorders in CAMAC systems. The development of DASs has been technology

R and D toward highly repetitive laser fusion demonstration

International Nuclear Information System (INIS)

Satoh, Nakahiro; Matsukado, Koji; Watari, Takeshi; Sekine, Takashi; Takeuchi, Yasuki; Kawashima, Toshiyuki

2017-01-01

Hamamatsu Photonics conducts research on a unique continuous neutron generation method by integrating and utilizing elemental technologies such as laser, target, and measurement for laser nuclear fusion research. In addition, in collaboration with the Graduate School for the Creation of New Photonics Industries, Toyota Motor Corporation, and others, it is conducting research on laser fusion. As a high power laser of element technology, it constructed an ultrahigh intensity laser system by combining glass slab laser KURE-I and ultrahigh intensity femtosecond laser MATSU-I equipped with titanium sapphire transmitter, and achieved a peak output of 20 TW, It plans to further increase this to 100 TW. As other element technologies, it is also considering nuclear fusion fuel - target technology and light - high energy particle measurement technology. Regarding the demonstration of continuous generation of laser fusion neutrons, it performed 100 times of continuous laser beam irradiation at 1 Hz, and actually measured the number of neutrons generated. It measured 4.5x10 4 pieces of neutrons on average (maximum 10 5 ) with a frequency of 98%. Since 100% of neutron generation should occur in principle, in the future it will be necessary to enhancing laser collecting intensity and to improve solid particle number density in order to put this process into practical use as a neutron source. (A.O.)

Future with fusion power

International Nuclear Information System (INIS)

Hirschfeld, F.

1977-01-01

This article reviews several current approaches to the development of nuclear fusion power sources by the year 2000. First mentioned is the only project to develop a nonpolluting, radiation-free source by using only natural and nonradioactive isotopes (nuclei of deuterium, helium 3 and boron) as ''advanced'' fuels. This system will also be capable of direct conversion of the released energy into electricity. Next described is the PACER concept, in which thermonuclear burning of deuterium occurs in fusion explosion taking place underground (e.g., in a salt dome). The released energy is absorbed in high-pressure steam which is then piped to a surface heat exchanger to provide steam for a turbogenerator. After filtration, the steam is returned. The PACER system also produces fissionable fuel. The balance of the article reviews three ''magnetic fusion'' approaches. Tokamak, mirror and theta pinch systems utilize magnetic fields to confine a plasma for either pulsed or steady-state operation. The tokamak and theta pinch are toroidal in shape, while the mirror can be thought of as a magnetic field configuration of roughly tubular shape that confines the plasma by means of higher fields at the ends than at its center. The tokamak approach accounts for about 65 percent of the magnetic fusion research and development, while theta pinches and mirrors represent about 15 percent each. Refs

Fusion power plant availability study

International Nuclear Information System (INIS)

Ladra, D.; Sanguinetti, G.P.; Stube, E.

2001-01-01

The consideration of fusion as an alternative energy source will need to demonstrate that Fusion Power Plant (FPP) design, operating and maintenance characteristics meet the electrical market requirements forecast for the second half of this century. Until now, fusion has been developed in the framework of research and development programmes following natural technological trends. To bring a greater sense of realism to commercial viability and to guarantee that technology-driven fusion development responds to the demands of the market, a conceptual study of future commercial FPPs has been performed with a Power Plant Availability (PPA) study aimed at identifying the aspects affecting the availability and generating costs of FPPs. EFET, who has also been involved in the study, can visualise it from two different points of view; that of the industry (ANSALDO, IBERTEF, SIEMENS, NNC) and that of the utilities (BELGATOM, FRAMATOME, FORTUM). The work carried out covered the following points: socio-economic forecasting; safety and licensing; operation and maintenance; waste and decommissioning; availability and reliability. The following are the most relevant findings, conclusions and recommendations for all these aspects: Demonstrate definitively that the physical principles of nuclear fusion have been validated by means of experiments; Establish a European Industrial Group to support the demonstration phases; Create the financial and contracting framework required to construct these installations. Secure the necessary budgets for the European Union's 5th and 6th Research Programmes. Look for supplementary long term financing sources; The existing Regulatory Bodies should combine to form a single Working Group with responsibility for fusion reactor safety and licensing activities, working on the harmonisation of the regulatory processes, developing FPP safety criteria and guidelines and reviewing industry standards; To be competitive, FPPs should have high availability

From Data Acquisition to Data Fusion: A Comprehensive Review and a Roadmap for the Identification of Activities of Daily Living Using Mobile Devices

Directory of Open Access Journals (Sweden)

Ivan Miguel Pires

2016-02-01

Full Text Available This paper focuses on the research on the state of the art for sensor fusion techniques, applied to the sensors embedded in mobile devices, as a means to help identify the mobile device user’s daily activities. Sensor data fusion techniques are used to consolidate the data collected from several sensors, increasing the reliability of the algorithms for the identification of the different activities. However, mobile devices have several constraints, e.g., low memory, low battery life and low processing power, and some data fusion techniques are not suited to this scenario. The main purpose of this paper is to present an overview of the state of the art to identify examples of sensor data fusion techniques that can be applied to the sensors available in mobile devices aiming to identify activities of daily living (ADLs.

From Data Acquisition to Data Fusion: A Comprehensive Review and a Roadmap for the Identification of Activities of Daily Living Using Mobile Devices

Science.gov (United States)

Pires, Ivan Miguel; Garcia, Nuno M.; Pombo, Nuno; Flórez-Revuelta, Francisco

2016-01-01

This paper focuses on the research on the state of the art for sensor fusion techniques, applied to the sensors embedded in mobile devices, as a means to help identify the mobile device user’s daily activities. Sensor data fusion techniques are used to consolidate the data collected from several sensors, increasing the reliability of the algorithms for the identification of the different activities. However, mobile devices have several constraints, e.g., low memory, low battery life and low processing power, and some data fusion techniques are not suited to this scenario. The main purpose of this paper is to present an overview of the state of the art to identify examples of sensor data fusion techniques that can be applied to the sensors available in mobile devices aiming to identify activities of daily living (ADLs). PMID:26848664

Fusion power plant simulations: a progress report

International Nuclear Information System (INIS)

Cook, J.M.; Pattern, J.S.; Amend, W.E.

1976-01-01

The objective of the fusion systems analysis at ANL is to develop simulations to compare alternative conceptual designs of magnetically confined fusion power plants. The power plant computer simulation progress is described. Some system studies are also discussed

Pinch me - I'm fusing. Fusion Power - what is it? What is a z pinch? And why are z-pinches a promising fusion power technology?

International Nuclear Information System (INIS)

DERZON, MARK S.

2000-01-01

The process of combining nuclei (the protons and neutrons inside an atomic nucleus) together with a release of kinetic energy is called fusion. This process powers the Sun, it contributes to the world stockpile of weapons of mass destruction and may one day generate safe, clean electrical power. Understanding the intricacies of fusion power, promised for 50 years, is sometimes difficult because there are a number of ways of doing it. There is hot fusion, cold fusion and con-fusion. Hot fusion is what powers suns through the conversion of mass energy to kinetic energy. Cold fusion generates con-fusion and nobody really knows what it is. Even so, no one is generating electrical power for you and me with either method. In this article the author points out some basic features of the mainstream approaches taken to hot fusion power, as well as describe why z pinches are worth pursuing as a driver for a power reactor and how it may one day generate electrical power for mankind

Utility requirements for fusion power

International Nuclear Information System (INIS)

DeBellis, R.J.

1977-03-01

A four-man month study was undertaken to identify utility requirements of fusion power and define a role for the utilities in the fusion development process during the 1980s. This report, preliminary in nature, serves mainly as a planning document for future requirements analyses. A requirements organization was defined to consist of three major chronological phases: research and development, plant installation, and plant operation. Thirty-seven requirements were identified, covering all categories. In addition, training, environment, safety, licensing, and utility model were identified as five matrix-type requirements. As the requirement definition process continued during the study period, comments received from utility representatives revealed a consistency of key issues in the fusion development process. These issues form the basis for the eventual establishment of definitive roles for the utilities during the 1980s. The issues are not meant to reflect a negative view of fusion, but are items that must be solved before fusion can be introduced commercially as an electrical power source. As a result of this requirements study, preliminary candidate roles for the utilities in the fusion development process during the 1980s were identified as public education, commercialization studies, industry investment analyses, training plan implementation, alternate reactor concept development, ERDA concept design review, and requirements refinement

Health physics appraisal guidelines for fusion/confinement devices

International Nuclear Information System (INIS)

Neeson, P.M.

1987-01-01

Several types of fusion/confinement devices have been developed for a variety of research applications. The health physics considerations for these devices can vary, depending on a number of parameters. This paper presents guidelines for health physics appraisal of such devices, which can be tailored to apply to specific systems. The guidelines can also be useful for establishing ongoing health physics programs for safe operation of the devices

Structural materials requirements for in-vessel components of fusion power plants

International Nuclear Information System (INIS)

Schaaf, B. van der

2000-01-01

The economic production of fusion energy is determined by principal choices such as using magnetic plasma confinement or generating inertial fusion energy. The first generation power plants will use deuterium and tritium mixtures as fuel, producing large amounts of highly energetic neutrons resulting in radiation damage in materials. In the far future the advanced fuels, 3 He or 11 B, determine power plant designs with less radiation damage than in the first generation. The first generation power plants design must anticipate radiation damage. Solid sacrificing armour or liquid layers could limit component replacements costs to economic levels. There is more than radiation damage resistance to determine the successful application of structural materials. High endurance against cyclic loading is a prominent requirement, both for magnetic and inertial fusion energy power plants. For high efficiency and compactness of the plant, elevated temperature behaviour should be attractive. Safety and environmental requirements demand that materials have low activation potential and little toxic effects under both normal and accident conditions. The long-term contenders for fusion power plant components near the plasma are materials in the range from innovative steels, such as reduced activation ferritic martensitic steels, to highly advanced ceramic composites based on silicon carbide, and chromium alloys. The steels follow an evolutionary path to basic plant efficiencies. The competition on the energy market in the middle of the next century might necessitate the riskier but more rewarding development of SiCSiC composites or chromium alloys

Three-dimensional Core Design of a Super Fast Reactor with a High Power Density

International Nuclear Information System (INIS)

Cao, Liangzhi; Oka, Yoshiaki; Ishiwatari, Yuki; Ikejiri, Satoshi; Ju, Haitao

2010-01-01

The SuperCritical Water-cooled Reactor (SCWR) pursues high power density to reduce its capital cost. The fast spectrum SCWR, called a super fast reactor, can be designed with a higher power density than thermal spectrum SCWR. The mechanism of increasing the average power density of the super fast reactor is studied theoretically and numerically. Some key parameters affecting the average power density, including fuel pin outer diameter, fuel pitch, power peaking factor, and the fraction of seed assemblies, are analyzed and optimized to achieve a more compact core. Based on those sensitivity analyses, a compact super fast reactor is successfully designed with an average power density of 294.8 W/cm 3 . The core characteristics are analyzed by using three-dimensional neutronics/thermal-hydraulics coupling method. Numerical results show that all of the design criteria and goals are satisfied

The impact of hybrid energy storage on power quality, when high power pulsed DC loads are operated on a microgrid testbed

Science.gov (United States)

Kelley, Jay Paul

As the Navy's demands for high power transient loads evolves, so too does the need for alternative energy sources to back-up the more traditional power generation. Such applications in need of support include electrical grid backup and directed energy weapon systems such as electromagnetic launchers, laser systems, and high power microwave generators, among others. Among the alternative generation sources receiving considerable attention are energy storage devices such as rechargeable electrochemical batteries and capacitors. In such applications as those mentioned above, these energy storage devices offer the ability to serve a dual role as both a power source to the various loads as well high power loads themselves to the continual generation when the high power transient loads are in periods of downtime. With the recent developments in electrochemical energy storage, lithium-ion batteries (LIBs) seem like the obvious choice, but previous research has shown that the elevated rates of charging can be detrimental to both the cycle life and the operational life span of the device. In order to preserve the batteries, their charge rate must be limited. One proposed method to accomplish the dual role task mentioned above, while preserving the life of the batteries, is by combining high energy density LIBs with high power density electric double layer capacitors (EDLCs) or lithium-ion capacitors (LICs) using controllable power electronics to adjust the flow of power to and from each device. Such a configuration is typically referred to as hybrid energy storage module (HESM). While shipboard generators start up, the combined high energy density and high power density of the HESM provides the capability to source critical loads for an extended period of time at the high rates they demand. Once the generator is operationally efficient, the HESM can act as a high energy reservoir to harvest the energy from the generator while the loads are in short periods of inactivity

Inertial fusion and energy production

International Nuclear Information System (INIS)

Holzrichter, J.F.

1982-01-01

Inertial-confinement fusion (ICF) is a technology for releasing nuclear energy from the fusion of light nuclei. For energy production, the most reactive hydrogen isotopes (deuterium (D) and tritium (T)) are commonly considered. The energy aplication requires the compression of a few milligrams of a DT mixture to great density, approximately 1000 times its liquid-state density, and to a high temperature, nearly 100 million 0 K. Under these conditions, efficient nuclear-fusion reactions occur, which can result in over 30% burn-up of the fusion fuel. The high density and temperature can be achieved by focusing very powerful laser or ion beams onto the target. The resultant ablation of the outer layers of the target compresses the fuel in the target, DT ignition occurs, and burn-up of the fuel results as the thermonuclear burn wave propagates outward. The DT-fuel burn-up occurs in about 199 picoseconds. On this short time scale, inertial forces are sufficiently strong to prevent target disassembly before fuel burn-up occurs. The energy released by the DT fusion is projected to be several hundred times greater than the energy delivered by the driver. The present statuds of ICF technology is described

Study of novel plasma devices generated by high power lasers coupled with a micro-pulse power technology

International Nuclear Information System (INIS)

Nishida, A; Chen, Z L; Jin, Z; Kondo, K; Nakagawa, M; Kodama, R; Arima, H; Yoneda, H

2008-01-01

The authors have proposed introducing a micro pulse power technology in high power laser plasma experiments to boost up the return current, resulting in efficiently guiding of energetic electrons. High current pulse power generators with a pulse laser trigger system generate high-density plasma that is well conductor. To efficiently guiding by using a micro pulse power, we estimated parameter of a micro pulse power system that is voltage of rise time, current, charging voltage and capacitance

Theory of high density laser fusion

International Nuclear Information System (INIS)

Zimmerman, G.B.; Nuckolls, J.H.

1975-01-01

A basic laser fusion scheme is presented. Some of its subtleties are described and the theoretical difficulties which now appear to be the major obstacles are considered. Interpretations of some recent laser compression experiments are given. (U.S.)

Studies in High Current Density Ion Sources for Heavy Ion Fusion Applications

Energy Technology Data Exchange (ETDEWEB)

Chacon-Golcher, Edwin [Univ. of California, Berkeley, CA (United States)

2002-06-01

This dissertation develops diverse research on small (diameter ~ few mm), high current density (J ~ several tens of mA/cm²) heavy ion sources. The research has been developed in the context of a programmatic interest within the Heavy Ion Fusion (HIF) Program to explore alternative architectures in the beam injection systems that use the merging of small, bright beams. An ion gun was designed and built for these experiments. Results of average current density yield () at different operating conditions are presented for K⁺ and Cs⁺ contact ionization sources and potassium aluminum silicate sources. Maximum values for a K⁺ beam of ~90 mA/cm² were observed in 2.3 μs pulses. Measurements of beam intensity profiles and emittances are included. Measurements of neutral particle desorption are presented at different operating conditions which lead to a better understanding of the underlying atomic diffusion processes that determine the lifetime of the emitter. Estimates of diffusion times consistent with measurements are presented, as well as estimates of maximum repetition rates achievable. Diverse studies performed on the composition and preparation of alkali aluminosilicate ion sources are also presented. In addition, this work includes preliminary work carried out exploring the viability of an argon plasma ion source and a bismuth metal vapor vacuum arc (MEVVA) ion source. For the former ion source, fast rise-times (~ 1 μs), high current densities (~ 100 mA/cm⁺) and low operating pressures (< 2 mtorr) were verified. For the latter, high but acceptable levels of beam emittance were measured (ε_n ≤ 0.006 π· mm · mrad) although measured currents differed from the desired ones (I ~ 5mA) by about a factor of 10.

An approach to next step device optimisation

International Nuclear Information System (INIS)

Salpietro, E.

2000-01-01

The requirements for ITER EDA were to achieve ignition with a good safety margin, and controlled long inductive burn. These requirements lead to a big device, which requested a too ambitious step to be undertaken by the world fusion community. More realistic objectives for a next step device shall be to demonstrate the net production of energy with a high energy gain factor (Q) and a high boot strap current fraction (>60%) which is required for a Fusion Power Plant (FPP). The Next Step Device (NSD) shall also allow operation flexibility in order to explore a large range of plasma parameters to find out the optimum concept for the fusion power plant prototype. These requirements could be too demanding for one single device and could probably be better explored in a strongly integrated world programme. The cost of one or more devices is the decisive factor for the choice of the fusion power development programme strategy. The plasma elongation and triangularity have a strong impact in the cost of the device and are limited by the plasma vertical position control issue. The distance between plasma separatrix and the toroidal field conductor does not vary a lot between devices. It is determined by the sum of the distance between first wall-plasma sepratrix and the thickness of the nuclear shield required to protect the toroidal field coil insultation. The thickness of the TF coil is determined by the allowable stresses and superconducting characteristics. The outer radius of the central solenoid is the result of an optimisation to provide the magnetic flux to inductively drive the plasma. Therefore, in order to achieve the objectives for Q and boot-strap current fractions at the minimum cost, the plasma aspect ratio and magnetic field value shall be determined. The paper will present the critical issues for the next device and will make considerations on the optimal way to proceed towards the realisation of the fusion power plant

Potential for use of high-temperature superconductors in fusion reactors

International Nuclear Information System (INIS)

Hull, J.R.

1991-01-01

The present rate of development of high-temperature superconductors (HTSs) is sufficiently rapid that there may be opportunities for their use in contemporary fusion devices such as the International Thermonuclear Experimental Reactor (ITER). The most likely 1application is for delivering power to the superconducting magnets, especially in substituting for the current leads between the temperatures of 4 K and 77K. A second possible application of HTSs is as a liquid-nitrogen-cooled power bus, connecting the power supplies to the magnets, thus reducing the ohmic heating losses over these relatively long cables. A third potential application of HTSs is as an inner high-field winding of the toroidal field coils that would operate at ∼20 K. While the use of higher temperature magnets offers significant advantages to the reactor system, it is unlikely that tested conductors of this type will be available within the ITER time frame. 23 refs., 2 figs

Compact fusion energy based on the spherical tokamak

Science.gov (United States)

Sykes, A.; Costley, A. E.; Windsor, C. G.; Asunta, O.; Brittles, G.; Buxton, P.; Chuyanov, V.; Connor, J. W.; Gryaznevich, M. P.; Huang, B.; Hugill, J.; Kukushkin, A.; Kingham, D.; Langtry, A. V.; McNamara, S.; Morgan, J. G.; Noonan, P.; Ross, J. S. H.; Shevchenko, V.; Slade, R.; Smith, G.

2018-01-01

Tokamak Energy Ltd, UK, is developing spherical tokamaks using high temperature superconductor magnets as a possible route to fusion power using relatively small devices. We present an overview of the development programme including details of the enabling technologies, the key modelling methods and results, and the remaining challenges on the path to compact fusion.

DD fusion neutron production at UW-Madison using IEC devices

Science.gov (United States)

Fancher, Aaron; Michalak, Matt; Kulcinski, Gerald; Santarius, John; Bonomo, Richard

2017-10-01

An inertial electrostatic confinement (IEC) device using spherical, gridded electrodes at high voltage accelerates deuterium ions, allowing for neutrons to be produced within the device from DD fusion reactions. The effects of the device cathode voltage (30-170 kV), current (30-100 mA), and pressure (0.15-1.25 mTorr) on the neutron production rate have been measured. New high voltage capabilities have resulted in the achievement of a steady state neutron production rate of 3.3x108 n/s at 175 kV, 100 mA, and 1.0 mTorr of deuterium. Applications of IEC devices include the production of DD neutrons to detect chemical explosives and special nuclear materials using active interrogation methods. Research supported by US Dept. of Homeland Security Grant 2015-DN-077-AR1095 and the Grainger Foundation.

Pulsed power ion accelerators for inertially confined fusion