Fusion Energy Postdoctoral Research Program, Professional Development Program: FY 1987 annual report

International Nuclear Information System (INIS)

1988-01-01

In FY 1986, Oak Ridge Associated Universities (ORAU) initiated two programs for the US Department of Energy (DOE), Office of Fusion Energy (OFE): the Fusion Energy Postdoctoral Research Program and the Fusion Energy Professional Development Program. These programs provide opportunities to conduct collaborative research in magnetic fusion energy research and development programs at DOE laboratories and contractor sites. Participants become trained in advanced fusion energy research, interact with outstanding professionals, and become familiar with energy-related national issues while making personal contributions to the search for solutions to scientific problems. Both programs enhance the national fusion energy research and development effort by providing channels for the exchange of scientists and engineers, the diffusion of ideas and knowledge, and the transfer of relevant technologies. These programs, along with the Magnetic Fusion Energy Science and Technology Fellowship Programs, compose the fusion energy manpower development programs administered by ORAU for DOE/OFE

Near-Barrier Fusion of Heavy Nuclei. Coupling of the Channels

CERN Document Server

Zagrebaev, V I

2003-01-01

The problem of quantum description of near-barrier fusion of heavy nuclei taking place under strong coupling of relative motion with rotation of deformed nuclei and with dynamic deformations of their surfaces is studied in the paper. A new effective method is proposed for numerical solution of a set of coupled Schrodinger equations with boundary conditions corresponding to a full absorption of the flux penetrated through the multi-dimensional Coulomb barrier. The method has no limitation on the number of coupled channels and allows one to calculate fusion cross-sections of very heavy nuclei used for synthesis of super-heavy elements. A combined analysis of the multi-dimensional potential energy surface relief and the multi-channel wave function in the vicinity of the Coulomb barrier gives a clear interpretation of near-barrier fusion dynamics. Comparison with experimental data and with semi-empirical model calculations is performed. The computing codes are allocated at the web-server http://nrv.jinr.ru/nrv/ w...

Small suppression of the complete fusion of {sup 6}Li + {sup 28}Si reaction at near barrier energies

Energy Technology Data Exchange (ETDEWEB)

Sinha, Mandira [Bose Institute, Department of Physics, Kolkata (India); Lubian, J. [Universidade Federal Fluminense, Instituto de Fisica, Niteroi, Rio de Janeiro (Brazil)

2017-11-15

The incomplete fusion cross section of the {sup 6}Li + {sup 28}Si weakly bound system at above barrier energies was deduced from the measured γ-ray cross sections. The complete fusion cross section was estimated from the measured total fusion and incomplete fusion cross section and is found to be 85-100% of the total fusion cross section. The coupled channel calculation has been performed considering ground and first excited states of {sup 28}Si target. The fusion cross section estimated from coupled channel calculation shows good agreement with measured total fusion cross section at higher energies. The suppression of about 15% of the fusion cross section predicted by coupled channel calculation shows good agreement with the complete fusion cross section. The effect of the channel couplings on the elastic scattering angular distribution is also investigated. (orig.)

Fusion energy 2000. Fusion energy 1998 (2001 Edition). Proceedings

International Nuclear Information System (INIS)

2001-01-01

This CD-ROM contains the Proceedings of 18th International Conference on Fusion Energy. It also contains an updated version of the Fusion Energy Conference 1998 Proceedings (38 additional papers included) as well as information on how to use this CD-ROM. The 18th International Atomic Energy Agency Fusion Energy Conference (FEC-2000) was held in Sorrento, Italy, 4-10 October 2000. 573 participants from over thirty countries and three international organizations took part in this Conference. The Conference was organized by the IAEA in co-operation with the Italian National Agency for New Technology, Energy and Environment (ENEA). Around 400 papers were presented in 22 oral and 8 poster sessions on magnetic confinement experiments, inertial fusion energy, plasma heating and current drive, ITER engineering design activities, magnetic confinement theory, innovative concepts, fusion technology, and safety and environment aspects. The 17th International Atomic Energy Agency (IAEA) Fusion Energy Conference was held in Yokohama, Japan, 19-24 October 1999. This 6-day conference, which was attended by 835 participants from over 30 countries and two international organizations, was organized by the IAEA in co-operation with the Japan Atomic Energy Research Institute (JAERI). More than 360 papers plus 5 summary talks were presented in 23 oral and 8 poster sessions on magnetic confinement and experiments, inertial fusion energy, plasma heating and current drive, ITER engineering design activities, magnetic confinement theory, innovative concepts and fusion technology

A simulation of low energy channeling of protons in silicon

International Nuclear Information System (INIS)

Sabin, J.R.

1994-01-01

The authors present early results from the CHANNEL code, which simulates the passage of ionized projectiles through bulk solids. CHANNEL solves the classical equations of motion for the projectile using the force obtained from the gradient of the quantum mechanically derived coulombic potential of the solid (determined via a full potential augmented plane wave FLAPW calculation on the bulk) and a quantum mechanical energy dissipation term, the stopping power, as determined from the local electron density, using the method of Echenique, Nieminen, and Ritchie. The code then generates the trajectory of the ionic projectile for a given initial velocity and a given incident position on the unit cell face. For each incident projectile velocity, the authors generate trajectories for incidence distributed over the channel face. The distribution of ranges generates an implantation profile. In this paper, they report ion (proton) implantation profiles for low energy protons with initial velocity along the (100) and (110) channel directions of diamond structured Silicon

Search for entrance channel effects in fusion reactions via neutron evaporation

International Nuclear Information System (INIS)

Ajay Kumar; Kaur, J.; Kumar, A.; Singh, G.; Govil, I.M.; Rakesh Kumar; Datta, S.K.; Chatterjee, M.B.; Yogi, B.K.

2001-01-01

It is generally expected that the compound nuclei formed at the given excitation energies and the angular momenta follow a statistical decay pattern independent of a particular reaction that led to fusion. In order to search the entrance channel effects in the decay of compound nucleus, the reaction 16 O + 64 Zn at oxygen beam energy of 91 MeV and 95 MeV are investigated

Nuclear fusion ion beam source composed of optimum channel wall

International Nuclear Information System (INIS)

Furukaw, T.

2007-01-01

Full text of publication follows: Numerical and experimental researches of the hall-type beam accelerator was conducted by highlighting both neutral species and material of acceleration channel wall. The hall-type beam accelerator is expected as ion beam source for nuclear fusion since it could product ion beam density over 10 3 times as high as that of electrostatic accelerator, which is used regularly as beam heating device, because it is proven that the beam heating method could accelerate ion to high energy beam by electric field and heat plasma to ultra high temperature of 100 million degrees or more. At high-voltage mode of DC regime that is normal operational condition, however, the various plasma MHD (magneto-hydrodynamic) instabilities are generated. In particular, the large-amplitude and low-frequency plasma MHD instability in the tens of kHz among them has been a serious problem that should be solved to improve the operational stability and the system durability. So, we propose a hall-type beam accelerator with new design concepts; both acquisition of simultaneous solution for reducing the plasma MHD instability and the accelerator core overheating and optimum combination of the acceleration channel wall material. The technologies for this concept are as follows: 1) To increase neutral species velocity-inlet in acceleration channel by preheating propellant through circularly propellant conduit line inside accelerator system could bring about the lower amplitude of the instability. 2) Through this method, the accelerator system is cooled, and the higher thrust and specific-impulse is produced with hardly changing thrust efficiency at the same time. 3) To select BN (Boron- Nitride) and Al 2 O 3 as wall material of ionization- and acceleration-zone in acceleration channel respectively having different secondary-electron emission-coefficient could achieve the higher-efficiency and -durability. The hall-type beam accelerator designed using these technologies

Fusion of 6Li with 159Tb at near-barrier energies

International Nuclear Information System (INIS)

Pradhan, M. K.; Mukherjee, A.; Basu, P.; Goswami, A.; Kshetri, R.; Roy, Subinit; Chowdhury, P. Roy; Sarkar, M. Saha; Palit, R.; Parkar, V. V.; Santra, S.; Ray, M.

2011-01-01

Complete and incomplete fusion cross sections for 6 Li + 159 Tb have been measured at energies around the Coulomb barrier by the γ-ray method. The measurements show that the complete fusion cross sections at above-barrier energies are suppressed by ∼34% compared to coupled-channel calculations. A comparison of the complete fusion cross sections at above-barrier energies with the existing data for 11,10 B + 159 Tb and 7 Li + 159 Tb shows that the extent of suppression is correlated with the α separation energies of the projectiles. It has been argued that the Dy isotopes produced in the reaction 6 Li + 159 Tb at below-barrier energies are primarily due to the d transfer to unbound states of 159 Tb, while both transfer and incomplete fusion processes contribute at above-barrier energies.

Hindrance of O16+Pb208 fusion at extreme sub-barrier energies

Science.gov (United States)

Esbensen, Henning; Mişicu, Şerban

2007-11-01

We analyze the fusion data for O16+Pb208 using coupled-channels calculations. We include couplings to the low-lying surface excitations of the projectile and target and study the effect of the (O16,O17) one-neutron pickup. The hindrance of the fusion data that is observed at energies far below the Coulomb barrier cannot be explained by a conventional ion-ion potential and defining the fusion in terms of ingoing-wave boundary conditions (IWBC). We show that the hindrance can be explained fairly well by applying the M3Y double-folding potential which has been corrected with a calibrated, repulsive term that simulates the effect of nuclear incompressibility. We show that the coupling to one-neutron transfer channels plays a crucial role in improving the fit to the data. The best fit is achieved by increasing the transfer strength by 25% relative to the strength that is required to reproduce the one-neutron transfer data. The larger strength is not unrealistic because the calculated inelastic plus transfer cross section is in good agreement with the measured quasielastic cross section. We finally discuss the problem of reproducing the fusion data at energies far above the Coulomb barrier. Here we do not account for the data when we apply the IWBC but the discrepancy is essentially eliminated by applying the M3Y+repulsion potential and a weak, short-ranged imaginary potential.

Continuous internal channels formed in aluminum fusion welds

Science.gov (United States)

Gault, J.; Sabo, W.

1967-01-01

Process produces continuous internal channel systems on a repeatable basis in 2014-T6 aluminum. Standard machining forms the initial channel, which is filled with tungsten carbide powder. TIG machine fusion welding completes formation of the channel. Chem-mill techniques enlarge it to the desired size.

How does incomplete fusion show up at slightly above barrier energies?

Directory of Open Access Journals (Sweden)

Prasad R.

2012-02-01

Full Text Available Experimental results on the onset of incomplete fusion at slightly above barrier energies are discussed in this paper. Spin-distributions of evaporation residues populated via complete and/or incomplete fusion of 12C,16O (Elab ≈ 4–7 MeV with 169Tm have been measured to probe associated ℓ–values. Particle (Z=1,2 – γ – coincidence technique has been used for channel selection. Entirely different entry state spin populations have been observed during the de-excitation of complete and incomplete composites. The complete fusion residues are found to be strongly fed over a broad spin range. While, a narrow range feeding for only high spin states has been observed in case of incomplete fusion residues. In the present work, incomplete fusion is shown to be a promising tool to populate high spin states in final reaction products. For better insight into the onset and strength of incomplete fusion, the relative contributions of complete and incomplete fusion have been deduced from the analysis of excitation functions and forward recoil ranges. A significant fraction of ICF has been observed even at energy as low as ≈ 7% above the barrier. The relative strengths of complete and incomplete fusion deduced from the analysis of forward-recoil-ranges and excitation functions complement each other. All the available results are discussed in light of the Morgenstern’s mass-asymmetry systematics. Incomplete fusion fraction is found to be large for more mass-asymmetric systems for individual projectiles, which points towards the projectile structure effect on incomplete fusion fraction. Experimentally measured forward ranges of recoils complement the existence of incomplete fusion at slightly above barrier energies, where more than one linear-momentum-transfer components associated with full- and/or partial-fusion of projectile(s have been observed. Present results conclusively demonstrate the possibility to selectively populate high spin states

Channel for Applied Investigations on Low Energy Ion Beams of Cyclotron DC-60

CERN Document Server

Gikal, B N; Borisenko, A N; Fateev, A A; Gulbekyan, G G; Kalagin, I V; Kazacha, V I; Kazarinov, N Yu; Kolesov, I V; Lebedev, N I; Lysukhin, S N; Melnikov, V N

2006-01-01

The channel intended for carrying out applied investigations on the low energy ion beams having the kinetic energy 25 $Z/A$ keV/a.u. and transported from the ECR-source to a target is worked out. The channel structure and parameters of all its optics elements are defined. The calculation results of different ion types transportation are given. It is shown that ions having the ratio of their mass to charge Z/A=2-20 can be transported in the worked out channel with enough high expected efficiency. At that the ion beam diameter on the target is $\\sim$40 mm. The characteristics of the basic optical elements of the channel are also given.

Effect of hyperon channels in low-energy k-d scattering

International Nuclear Information System (INIS)

Schick, L.H.; Gibson, B.F.

1978-01-01

Within the framework of a Faddeev formalism and an implicit hyperon channel approximation, we have calculated K - d elastic, total, and reaction cross sections for incident kaon laboratory momenta up to 120 Mev/c. We have used as input two different (slightly modified) multichannel M matrix fits to low-energy anti KN scattering, each of which contains explicitly the πY channels, as well as a single channel representation of the anti KN interaction in which the hyperon channels appear only through their contributions to the imaginary parts of the anti KN scattering lengths. The K - d cross sections obtained with the single channel anti KN input differ by only some 10% from those for which we used the multichannel anti KN input. The D - d cross sections calculated using anti KN input parameters from each of the two separate M matrix fits differ across the entire momentum range investigated by 25-35%. (orig.) [de

The perspectives of fusion energy: The roadmap towards energy production and fusion energy in a distributed energy system

DEFF Research Database (Denmark)

Naulin, Volker; Juul Rasmussen, Jens; Korsholm, Søren Bang

2014-01-01

at very high temperature where all matter is in the plasma state as the involved energies are orders of magnitude higher than typical chemical binding energies. It is one of the great science and engineering challenges to construct a viable power plant based on fusion energy. Fusion research is a world...... The presentation will discuss the present status of the fusion energy research and review the EU Roadmap towards a fusion power plant. Further the cost of fusion energy is assessed as well as how it can be integrated in the distributed energy system......Controlled thermonuclear fusion has the potential of providing an environmentally friendly and inexhaustible energy source for mankind. Fusion energy, which powers our sun and the stars, is released when light elements, such as the hydrogen isotopes deuterium and tritium, fuse together. This occurs...

Research Needs for Magnetic Fusion Energy Sciences

Energy Technology Data Exchange (ETDEWEB)

Neilson, Hutch

2009-07-01

Nuclear fusion — the process that powers the sun — offers an environmentally benign, intrinsically safe energy source with an abundant supply of low-cost fuel. It is the focus of an international research program, including the ITER fusion collaboration, which involves seven parties representing half the world’s population. The realization of fusion power would change the economics and ecology of energy production as profoundly as petroleum exploitation did two centuries ago. The 21st century finds fusion research in a transformed landscape. The worldwide fusion community broadly agrees that the science has advanced to the point where an aggressive action plan, aimed at the remaining barriers to practical fusion energy, is warranted. At the same time, and largely because of its scientific advance, the program faces new challenges; above all it is challenged to demonstrate the timeliness of its promised benefits. In response to this changed landscape, the Office of Fusion Energy Sciences (OFES) in the US Department of Energy commissioned a number of community-based studies of the key scientific and technical foci of magnetic fusion research. The Research Needs Workshop (ReNeW) for Magnetic Fusion Energy Sciences is a capstone to these studies. In the context of magnetic fusion energy, ReNeW surveyed the issues identified in previous studies, and used them as a starting point to define and characterize the research activities that the advance of fusion as a practical energy source will require. Thus, ReNeW’s task was to identify (1) the scientific and technological research frontiers of the fusion program, and, especially, (2) a set of activities that will most effectively advance those frontiers. (Note that ReNeW was not charged with developing a strategic plan or timeline for the implementation of fusion power.)

Fusion in the energy system

DEFF Research Database (Denmark)

Fusion energy is the fundamental energy source of the Universe, as the energy of the Sun and the stars are produced by fusion of e.g. hydrogen to helium. Fusion energy research is a strongly international endeavor aiming at realizing fusion energy production in power plants on Earth. Reaching...... of integration into the future electricity system and socio-economic studies of fusion energy will be presented, referring to the programme of Socio-Economic Research on Fusion (SERF) under the European Fusion Energy Agreement (EFDA)....

Bi-channel Sensor Fusion for Automatic Sign Language Recognition

DEFF Research Database (Denmark)

Kim, Jonghwa; Wagner, Johannes; Rehm, Matthias

2008-01-01

In this paper, we investigate the mutual-complementary functionality of accelerometer (ACC) and electromyogram (EMG) for recognizing seven word-level sign vocabularies in German sign language (GSL). Results are discussed for the single channels and for feature-level fusion for the bichannel senso......-independent condition, where subjective differences do not allow for high recognition rates. Finally we discuss a problem of feature-level fusion caused by high disparity between accuracies of each single channel classification....

Consistent analysis of peripheral reaction channels and fusion for the 16,18O+58Ni systems

International Nuclear Information System (INIS)

Alves, J.J.S.; Gomes, P.R.S.; Lubian, J.; Chamon, L.C.; Pereira, D.; Anjos, R.M.; Rossi, E.S.; Silva, C.P.; Alvarez, M.A.G.; Nobre, G.P.A.; Gasques, L.R.

2005-01-01

We have measured elastic scattering and peripheral reaction channel cross sections for the 16,18 O+ 58 Ni systems at ELab=46 MeV. The data were analyzed through extensive coupled-channel calculations. It was investigated the consistency of the present analysis with a previous one at sub-barrier energies. Experimental fusion cross sections for these systems are also compared with the corresponding predictions of the coupled-channel calculations

Study of incomplete fusion reaction dynamics in 13C +165 Ho system and its dependence on various entrance channel parameters

Science.gov (United States)

Tali, Suhail A.; Kumar, Harish; Ansari, M. Afzal; Ali, Asif; Singh, D.; Ali, Rahbar; Giri, Pankaj K.; Linda, Sneha B.; Parashari, Siddharth; Kumar, R.; Singh, R. P.; Muralithar, S.

2018-02-01

The excitation functions for the evaporation residues populated in the interaction of 13C +165 Ho system have been measured at projectile energies ≈ 4-7 MeV/nucleon. Stacked foil activation technique followed by off-line γ-ray spectroscopy have been employed in the present work. The experimentally measured cross-sections are analyzed in the frame work of statistical model code PACE4, which takes into account only the complete fusion reaction cross-sections. The evaporation residues populated via xn and pxn channels were found to be in good agreement with the PACE4 predictions, while a significant enhancement in the measured cross-sections over PACE4 predictions is observed in case of α-emitting channels, which may be attributed to the incomplete fusion process. For the better understanding of incomplete fusion dynamics, the incomplete fusion fraction has also been deduced and its sensitivity with various entrance channel parameters like: projectile energy, mass-asymmetry, projectile structure in terms of Qα-value and Coulomb effect has been studied in the present work. The incomplete fusion fraction is found to increase with increasing the projectile energy and a strong projectile structure dependent mass-asymmetry systematic is also observed. The incomplete fusion fraction is also found to be small for more negative Qα-value projectile (13C) induced reactions as compared to less negative Qα-value projectiles (12C, 16O and 20Ne) induced reactions with the same target nucleus 165Ho. An interesting trend is obtained on further investigation of incomplete fusion dependence on Coulomb effect (ZPZT).

Coupled-channels analyses for 9,11Li + 208Pb fusion reactions with multi-neutron transfer couplings

Science.gov (United States)

Choi, Ki-Seok; Cheoun, Myung-Ki; So, W. Y.; Hagino, K.; Kim, K. S.

2018-05-01

We discuss the role of two-neutron transfer processes in the fusion reaction of the 9,11Li + 208Pb systems. We first analyze the 9Li + 208Pb reaction by taking into account the coupling to the 7Li + 210Pb channel. To this end, we assume that two neutrons are directly transferred to a single effective channel in 210Pb and solve the coupled-channels equations with the two channels. By adjusting the coupling strength and the effective Q-value, we successfully reproduce the experimental fusion cross sections for this system. We then analyze the 11Li + 208Pb reaction in a similar manner, that is, by taking into account three effective channels with 11Li + 208Pb, 9Li + 210Pb, and 7Li + 212Pb partitions. In order to take into account the halo structure of the 11Li nucleus, we construct the potential between 11Li and 208Pb with a double folding procedure, while we employ a Woods-Saxon type potential with the global Akyüz-Winther parameters for the other channels. Our calculation indicates that the multiple two-neutron transfer process plays a crucial role in the 11Li + 208Pb fusion reaction at energies around the Coulomb barrier.

Diagnostics of discharge channels for neutralized chamber transport in heavy ion fusion

International Nuclear Information System (INIS)

Niemann, C.; Penache, D.; Tauschwitz, A.; Rosmej, F.B.; Neff, S.; Birkner, R.; Constantin, C.; Knobloch, R.; Presura, R.; Yu, S.S.; Sharp, W.M.; Ponce, D.M.; Hoffmann, D.H.H.

2002-01-01

The final beam transport in the reactor chamber for heavy ion fusion in preformed plasma channels offers many attractive advantages compared to other transport modes. In the past few years, experiments at the Gesellschaft fuer Schwerionenforschung (GSI) accelerator facility have addressed the creation and investigation of discharge plasmas, designed for the transport of intense ion beams. Stable, self-standing channels of 50 cm length with currents up to 55 kA were initiated in low-pressure ammonia gas by a CO 2 -laser pulse along the channel axis before the discharge is triggered. The channels were characterized by several plasma diagnostics including interferometry and spectroscopy. We also present first experiments on laser-guided intersecting discharges

LIFE: The Case for Early Commercialization of Fusion Energy

International Nuclear Information System (INIS)

Anklam, T.; Simon, A.J.; Powers, S.; Meier, W.R.

2011-01-01

This paper presents the case for early commercialization of laser inertial fusion energy (LIFE). Results taken from systems modeling of the US electrical generating enterprise quantify the benefits of fusion energy in terms of carbon emission, nuclear waste and plutonium production avoidance. Sensitivity of benefits-gained to timing of market-entry is presented. These results show the importance of achieving market entry in the 2030 time frame. Economic modeling results show that fusion energy can be competitive with other low-carbon energy sources. The paper concludes with a description of the LIFE commercialization path. It proposes constructing a demonstration facility capable of continuous fusion operations within 10 to 15 years. This facility will qualify the processes and materials needed for a commercial fusion power plant.

Stored energy in fusion magnet materials irradiated at low temperatures

International Nuclear Information System (INIS)

Chaplin, R.L.; Kerchner, H.R.; Klabunde, C.E.; Coltman, R.R.

1989-08-01

During the power cycle of a fusion reactor, the radiation reaching the superconducting magnet system will produce an accumulation of immobile defects in the magnet materials. During a subsequent warm-up cycle of the magnet system, the defects will become mobile and interact to produce new defect configurations as well as some mutual defect annihilations which generate heat-the release of stored energy. This report presents a brief qualitative discussion of the mechanisms for the production and release of stored energy in irradiated materials, a theoretical analysis of the thermal response of irradiated materials, theoretical analysis of the thermal response of irradiated materials during warm-up, and a discussion of the possible impact of stored energy release on fusion magnet operation 20 refs

Smooth transition from sudden to adiabatic states in heavy-ion fusion reactions at deep-subbarrier incident energies

International Nuclear Information System (INIS)

Takatoshi, Ichikawa; Kouichi, Hagino; Akira, Iwamoto

2011-01-01

We propose a novel extension of the standard coupled-channel (CC) model in order to account for the steep falloff of fusion cross sections at deep-subbarrier incident energies. We introduce a damping factor in the coupling potential in the CC model, simulating smooth transitions from sudden to adiabatic states in deep- subbarrier fusion reactions. The CC model extended with the damping factor can reproduce well not only the steep falloff of the fusion cross section but also the saturation of the logarithmic derivatives for the fusion cross sections at deep-subbarrier energies for the 16 O+ 208 Pb, 64 Ni+ 64 Ni, and 58 Ni+ 58 Ni reactions at the deep-subbarrier energies. The important point in our model is that the transition takes place at different places for each Eigen channel. We conclude that the smooth transition from the two-body to the adiabatic one-body potential is responsible for the steep falloff of the fusion cross section

Determination of extra-push energies for fusion from differential fission cross-section measurements

International Nuclear Information System (INIS)

Ramamurthy, V.S.; Kapoor, S.S.

1993-01-01

Apparent discrepancies between values of extra-push energies for fusion of two heavy nuclei derived through measurements of fusion evaporation residue cross sections and of differential fission cross sections have been reported by Keller et al. We show here that with the inclusion of the recently proposed preequilibrium fission decay channel in the analysis, there is no inconsistency between the two sets of data in terms of the deduced extra-push energies

Magnetic fusion energy

International Nuclear Information System (INIS)

Anon.

1978-01-01

The efforts of the Chemical Technology Division in the area of fusion energy include fuel handling, processing, and containment. These studies are closely coordinated with the ORNL Fusion Energy Division. Current experimental studies are concerned with the development of vacuum pumps for fusion reactors, the evaluation and development of techniques for recovering tritium (fuel) from either solid or liquid lithium containing blankets, and the use of deep beds of sorbents as roughing pumps and/or transfer operations. In addition, a small effort is devoted to the support of the ORNL design of The Next Step (TNS) in tokamak reactor development. The more applied studies--vacuum pump development and TNS design--are funded by the DOE/Magnetic Fusion Energy, and the more fundamental studies--blanket recovery and sorption in deep beds--are funded by the DOE/Basic Energy Sciences

Fusion energy - an abundant energy source for the future

DEFF Research Database (Denmark)

Fusion energy is the fundamental energy source of the Universe, as the energy of the Sun and the stars are produced by fusion of e.g. hydrogen to helium. Fusion energy research is a strongly international endeavor aiming at realizing fusion energy production in power plants on Earth. Reaching...... this goal, mankind will have a sustainable base load energy source with abundant resources, having no CO2 release, and with no longlived radioactive waste. This presentation will describe the basics of fusion energy production and the status and future prospects of the research. Considerations...... of integration into the future electricity system and socio-economic studies of fusion energy will be presented, referring to the programme of Socio-Economic Research on Fusion (SERF) under the European Fusion Energy Agreement (EFDA)....

Indirect Study of the 16O+16O Fusion Reaction Toward Stellar Energies by the Trojan Horse Method

Directory of Open Access Journals (Sweden)

Hayakawa S.

2016-01-01

Full Text Available The 16O+16O fusion reaction is important in terms of the explosive oxygen burning process during late evolution stage of massive stars as well as understanding of the mechanism of low-energy heavy-ion fusion reactions. We aim to determine the excitation function for the most major exit channels, α+28Si and p+31P, toward stellar energies indirectly by the Trojan Horse Method via the 16O(20Ne, α28Siα and 16O(20Ne, p31Pα three-body reactions. We report preliminary results involving reaction identification, and determination of the momentum distribution of α-16O intercluster motion in the projectile 20Ne nucleus.

Fusion Energy Advisory Committee report on program strategy for US magnetic fusion energy research

International Nuclear Information System (INIS)

Conn, R.W.; Berkner, K.H.; Culler, F.L.; Davidson, R.C.; Dreyfus, D.A.; Holdren, J.P.; McCrory, R.L.; Parker, R.R.; Rosenbluth, M.N.; Siemon, R.E.; Staudhammer, P.; Weitzner, H.

1992-09-01

The Fusion Energy Advisory Committee (FEAC) was charged by the Department of Energy (DOE) with developing recommendations on how best to pursue the goal of a practical magnetic fusion reactor in the context of several budget scenarios covering the period FY 1994-FY 1998. Four budget scenarios were examined, each anchored to the FY 1993 figure of $337.9 million for fusion energy (less $9 million for inertial fusion energy which is not examined here)

The alpha channeling effect

Science.gov (United States)

Fisch, N. J.

2015-12-01

Alpha particles born through fusion reactions in a tokamak reactor tend to slow down on electrons, but that could take up to hundreds of milliseconds. Before that happens, the energy in these alpha particles can destabilize on collisionless timescales toroidal Alfven modes and other waves, in a way deleterious to energy confinement. However, it has been speculated that this energy might be instead be channeled into useful energy, so as to heat fuel ions or to drive current. Such a channeling needs to be catalyzed by waves Waves can produce diffusion in energy of the alpha particles in a way that is strictly coupled to diffusion in space. If these diffusion paths in energy-position space point from high energy in the center to low energy on the periphery, then alpha particles will be cooled while forced to the periphery. The energy from the alpha particles is absorbed by the wave. The amplified wave can then heat ions or drive current. This process or paradigm for extracting alpha particle energy collisionlessly has been called alpha channeling. While the effect is speculative, the upside potential for economical fusion is immense. The paradigm also operates more generally in other contexts of magnetically confined plasma.

Heat of Fusion Storage with High Solar Fraction for Solar Low Energy Buildings

DEFF Research Database (Denmark)

Schultz, Jørgen Munthe; Furbo, Simon

2006-01-01

to achieve 100% coverage of space heating and domestic hot water in a low energy house in a Danish climate with a solar heating system with 36 m² flat plate solar collector and approximately 10 m³ storage with sodium acetate. A traditional water storage solution aiming at 100% coverage will require a storage...... of the storage to cool down below the melting point without solidification preserving the heat of fusion energy. If the supercooled storage reaches the surrounding temperature no heat loss will take place until the supercooled salt is activated. The investigation shows that this concept makes it possible...

Fusion: Energy for the future

International Nuclear Information System (INIS)

1991-05-01

Fusion, which occurs in the sun and the stars, is a process of transforming matter into energy. If we can harness the fusion process on Earth, it opens the way to assuring that future generations will not want for heat and electric power. The purpose of this booklet is to introduce the concept of fusion energy as a viable, environmentally sustainable energy source for the twenty-first century. The booklet presents the basic principles of fusion, the global research and development effort in fusion, and Canada's programs for fusion research and development

Inertial fusion energy; L'energie de fusion inertielle

Energy Technology Data Exchange (ETDEWEB)

Decroisette, M.; Andre, M.; Bayer, C.; Juraszek, D. [CEA Bruyeres-le-Chatel, Dir. des Systemes d' Information (CEA/DIF), 91 (France); Le Garrec, B. [CEA Centre d' Etudes Scientifiques et Techniques d' Aquitaine, 33 - Le Barp (France); Deutsch, C. [Paris-11 Univ., 91 - Orsay (France); Migus, A. [Institut d' Optique Centre scientifique, 91 - Orsay (France)

2005-07-01

We first recall the scientific basis of inertial fusion and then describe a generic fusion reactor with the different components: the driver, the fusion chamber, the material treatment unit, the target factory and the turbines. We analyse the options proposed at the present time for the driver and for target irradiation scheme giving the state of art for each approach. We conclude by the presentation of LMJ (laser Megajoule) and NIF (national ignition facility) projects. These facilities aim to demonstrate the feasibility of laboratory DT ignition, first step toward Inertial Fusion Energy. (authors)

Estimating Total Fusion Cross Sections by Using a Coupled-Channel Method

Energy Technology Data Exchange (ETDEWEB)

Choi, Ki-Seok; Cheoun, Myung-Ki [Soongsil University, Seoul (Korea, Republic of); Kim, K. S. [Korea Aerospace University, Koyang (Korea, Republic of); Kim, T. H.; So, W. Y. [Kangwon National University at Dogye, Samcheok (Korea, Republic of)

2017-01-15

We calculate the total fusion cross sections for the {sup 6}He + {sup 209}Bi, {sup 6}Li + {sup 209}Bi,{sup 9}Be + {sup 208}Pb, {sup 10}Be + {sup 209}Bi, and {sup 11}Li + {sup 208}Pb systems by using a coupled-channel (CC) method and compare the results with the experimental data. In the CC approach for the total fusion cross sections, we exploit a globally determined Wood-Saxon potential with Aky¨uz-Winther parameters and couplings of the ground state to the low-lying excited states in the projectile and the target nuclei. The total fusion cross sections obtained with the CC are compared with those obtained without the CC couplings. The latter approach is tantamount to a one-dimensional barrier penetration model. Finally, our approach is applied to understand new data for the {sup 11}Li+{sup 208}Pb system. Possible ambiguities inherent in those approaches are discussed in detail for further applications to the fusion system of halo and/or neutron-rich nuclei.

Fusion as an energy option

International Nuclear Information System (INIS)

Steiner, D.

1976-01-01

The environmental issues, alternative fusion fuels, the economic potential, and the time scale of fusion power are assessed. It is common for the advocate of a long-term energy source to claim his source (fission, fusion, solar, etc.) as the ultimate solution to man's energy needs. The author does not believe that such a stance will lead to a rational energy policy. Dr. Steiner encourages a long-term energy policy that has as its goal the development of fission breeders, fusion, and solar energy--not be totally reliant on a single source. He does advocate vigorous funding for fusion, not because it is a guarantee for ''clean, limitless, and cheap power,'' but because it may provide an important energy option for the next century

Energy dependence of fusion evaporation-residue cross sections in the 28Si+12C reaction

International Nuclear Information System (INIS)

Vineyard, M.F.; Mateja, J.F.; Beck, C.; Atencio, S.E.; Dennis, L.C.; Frawley, A.D.; Henderson, D.J.; Janssens, R.V.F.; Kemper, K.W.; Kovar, D.G.; Maguire, C.F.; Padalino, S.J.; Prosser, F.W.; Stephans, G.S.F.; Tiede, M.A.; Wilkins, B.D.; Zingarelli, R.A.

1993-01-01

Fusion evaporation-residue cross sections for the 28 Si+ 12 C reaction have been measured in the energy range 18≤E c.m. ≤136 MeV using time-of-flight techniques. Velocity distributions of mass-identified reaction products were used to identify evaporation residues and to determine the complete-fusion cross sections at high energies. The data are in agreement with previously established systematics which indicate an entrance-channel mass-asymmetry dependence of the incomplete-fusion evaporation-residue process. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with earlier measurements and the predictions of existing models

Multi-channel motor evoked potential monitoring during anterior cervical discectomy and fusion

Directory of Open Access Journals (Sweden)

Dong-Gun Kim

Full Text Available Objectives: Anterior cervical discectomy and fusion (ACDF surgery is the most common surgical procedure for the cervical spine with low complication rate. Despite the potential prognostic benefit, intraoperative neurophysiological monitoring (IONM, a method for detecting impending neurological compromise, is not routinely used in ACDF surgery. The present study aimed to identify the potential benefits of monitoring multi-channel motor evoked potentials (MEPs during ACDF surgery. Methods: We retrospectively reviewed 200 consecutive patients who received IONM with multi-channel MEPs and somatosensory evoked potentials (SSEPs. On average, 9.2 muscles per patient were evaluated under MEP monitoring. Results: The rate of MEP change during surgery in the multi-level ACDF group was significantly higher than the single-level group. Two patients from the single-level ACDF group (1.7% and four patients from the multi-level ACDF group (4.9% experienced post-operative motor deficits. Multi-channel MEPs monitoring during single and multi-level ACDF surgery demonstrated higher sensitivity, specificity, positive predictive and negative predictive value than SSEP monitoring. Conclusions: Multi-channel MEP monitoring might be beneficial for the detection of segmental injury as well as long tract injury during single- and multi-level ACDF surgery. Significance: This is first large scale study to identify the usefulness of multi-channel MEPs in monitoring ACDF surgery. Keywords: Disc disease, Somatosensory evoked potentials, Intraoperative neurophysiological monitoring, Motor evoked potentials, Anterior cervical discectomy and fusion

Recent developments in heavy-ion fusion reactions around the Coulomb barrier

Directory of Open Access Journals (Sweden)

Hagino K.

2016-01-01

Full Text Available The nuclear fusion is a reaction to form a compound nucleus. It plays an important role in several circumstances in nuclear physics as well as in nuclear astrophysics, such as synthesis of superheavy elements and nucleosynthesis in stars. Here we discuss two recent theoretical developments in heavy-ion fusion reactions at energies around the Coulomb barrier. The first topic is a generalization of the Wong formula for fusion cross sections in a single-channel problem. By introducing an energy dependence to the barrier parameters, we show that the generalized formula leads to results practically indistinguishable from a full quantal calculation, even for light symmetric systems such as 12C+12C, for which fusion cross sections show an oscillatory behavior. We then discuss a semi-microscopic modeling of heavy-ion fusion reactions, which combine the coupled-channels approach to the state-of-the-art nuclear structure calculations for low-lying collective motions. We apply this method to subbarrier fusion reactions of 58Ni+58Ni and 40Ca+58Ni systems, and discuss the role of anharmonicity of the low-lying vibrational motions.

ROK-PRC Cooperation on Laser Fusion Energy

International Nuclear Information System (INIS)

Rhee, Yong Joo; Han, J. M.; Lee, S. M.; Nam, S. M.; Kwan, D. H.; Cha, Y. H.; Baek, S. H.

2009-03-01

International treaties on the reduction of green-house gases are now being established worldwide and Korea is supposed to join these treaties in a near future. Meanwhile the energy production via fission reactors proposed as a solution to this global environmental contamination has still inherent problems in that it also produces long-life radioactive nuclear waste in the long run, causing many serious social issues. Now the ultimate solution in this situation is believed to be the production of energy by the nuclear fusion reaction. In this project, the collaboration regarding high energy laser fusion has been carried out mainly at the Chinese facility such as ShengGuang II (SG II) laser facility, and ultrahigh intensity laser system of KAERI has been used for the small scale laser fusion and production of fast neutrons. Thomson scattering experiment to analyze the fusion plasma, opacity measurement to understand and develop the computer simulation techniques have been carried out at SG II facility, and experiments on implosion reaction which is basic to laser fusion as well as that of X-ray absorption and transmission have been done at the GEKKO XII facility of ILE, Japan. Satisfactory results both for Korea and China have been deduced by the strategy of project such that different approaches for high energy laser fusion and low energy laser fusion were applied. That is, Korean partner could get opportunities of doing experiments at the large laser facilities to get plasma diagnostic technologies and high density simulation technologies, besides the opportunity to participate in the K-C-J collaborative experiments of implosion and X-ray spectroscopy. And Chinese partner could solve their problem related to the laser fusion and neutron generation which were not successful even with their far high 300TW laser system

Fusion energy division computer systems network

International Nuclear Information System (INIS)

Hammons, C.E.

1980-12-01

The Fusion Energy Division of the Oak Ridge National Laboratory (ORNL) operated by Union Carbide Corporation Nuclear Division (UCC-ND) is primarily involved in the investigation of problems related to the use of controlled thermonuclear fusion as an energy source. The Fusion Energy Division supports investigations of experimental fusion devices and related fusion theory. This memo provides a brief overview of the computing environment in the Fusion Energy Division and the computing support provided to the experimental effort and theory research

Energy by nuclear fusion

International Nuclear Information System (INIS)

Buende, R.; Daenner, W.; Herold, H.; Raeder, J.

1976-12-01

This report reviews the state of knowledge in a number of fields of fusion research up to autumn 1976. Section 1 gives a very brief presentation of the elementary fusion reactions, the energies delivered by them and the most basic energy balances leading to Lawson-type diagrams. Section 2 outlines the reserves and cost of lithium and deuterium, gives estimates of the total energy available from DT fusion and comments on production technology, availlability and handling of the fuels. In section 3 a survey is given of the different concepts of magnetic confinement (stellarators, tokamaks, toroidal pinches, mirror machines, two-component plasmas), of confinement by walls, gas blankets and imploding liners and, finally, of the concepts of interial confinement (laser fusion, beam fusion). The reactors designed or outlined on the basis of the tokamak, high-β, mirror, and laser fusion concepts are presented in section 4, which is followed in section 5 by a discussion of the key problems of fusion power plants. The present-day knowledge of the cost structure of fusion power plants and the sensitivity of this structure with respect to the physical and technical assumptions made is analysed in section 6. Section 7 and 8 treat the aspects of safety and environment. The problems discussed include the hazard potentials of different designs (radiological, toxicological, and with respect to stored energies), release of radioactivity, possible kinds of malfunctioning, and the environmental impact of waste heat, radiation and radioactive waste (orig.) [de

Fusion Energy Update

International Nuclear Information System (INIS)

Whitson, M.O.

1982-01-01

Fusion Energy Update (CFU) provides monthly abstracting and indexing coverage of current scientific and technical reports, journal articles, conference papers and proceedings, books, patents, theses, and monographs for all sources on fusion energy. All information announced in CFU, plus additional backup information, is included in the energy information data base of the Department of Energy's Technical Information Center. The subject matter covered by CFU includes plasma physics, the physics and engineering of blankets, magnet coils and fields, power supplies and circuitry, cooling systems, fuel systems, radiation hazards, power conversion systems, inertial confinement systems, and component development and testing

Economic evaluations of fusion-based energy storage systems in an electric utility

International Nuclear Information System (INIS)

Hwang, W.G.

1977-01-01

The feasibility of introducing a fusion energy storage system, which consists of a fusion-fission reactor and a water-splitting process, in an electric utility was investigated. The fusion energy storage system was assumed to be run during off-peak periods in order to make use of unused, low fuel cost capacity of an electric utility. The fusion energy storage system produces both fissile fuel and hydrogen. The produced hydrogen was assumed to be transmitted through and stored in existing natural gas trunklines for later use during peak-load hours. The peaking units in the utility were assumed to burn the hydrogen. Reserve power is usually cheap on systems with heavy nuclear fission reactor installation. The system studied utilizes this cheap energy for producing expensive fuel. The thermochemical water-splitting process was employed to recover thermal energy from the fusion-fission reactor system. The cost of fusion energy storage systems as well as the value of produced fuel were calculated. In order to simulate the operations of the fusion energy storage system for a multi-year planning period, a computer program, FESUT (Fusion Energy Simulation at the University of Texas), was developed for the present study. Two year utility simulations with the fusion energy storage system were performed

Applications of Fusion Energy Sciences Research - Scientific Discoveries and New Technologies Beyond Fusion

International Nuclear Information System (INIS)

Wendt, Amy; Callis, Richard; Efthimion, Philip; Foster, John; Keane, Christopher; Onsager, Terry; O'Shea, Patrick

2015-01-01

Since the 1950s, scientists and engineers in the U.S. and around the world have worked hard to make an elusive goal to be achieved on Earth: harnessing the reaction that fuels the stars, namely fusion. Practical fusion would be a source of energy that is unlimited, safe, environmentally benign, available to all nations and not dependent on climate or the whims of the weather. Significant resources, most notably from the U.S. Department of Energy (DOE) Office of Fusion Energy Sciences (FES), have been devoted to pursuing that dream, and significant progress is being made in turning it into a reality. However, that is only part of the story. The process of creating a fusion-based energy supply on Earth has led to technological and scientific achievements of far-reaching impact that touch every aspect of our lives. Those largely unanticipated advances, spanning a wide variety of fields in science and technology, are the focus of this report. There are many synergies between research in plasma physics (the study of charged particles and fluids interacting with self-consistent electric and magnetic fields), high-energy physics, and condensed matter physics dating back many decades. For instance, the formulation of a mathematical theory of solitons, solitary waves which are seen in everything from plasmas to water waves to Bose-Einstein Condensates, has led to an equal span of applications, including the fields of optics, fluid mechanics and biophysics. Another example, the development of a precise criterion for transition to chaos in Hamiltonian systems, has offered insights into a range of phenomena including planetary orbits, two-person games and changes in the weather. Seven distinct areas of fusion energy sciences were identified and reviewed which have had a recent impact on fields of science, technology and engineering not directly associated with fusion energy: Basic plasma science; Low temperature plasmas; Space and astrophysical plasmas; High energy density

Applications of Fusion Energy Sciences Research - Scientific Discoveries and New Technologies Beyond Fusion

Energy Technology Data Exchange (ETDEWEB)

Wendt, Amy [Univ. of Wisconsin, Madison, WI (United States); Callis, Richard [General Atomics, San Diego, CA (United States); Efthimion, Philip [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Foster, John [Univ. of Michigan, Ann Arbor, MI (United States); Keane, Christopher [Washington State Univ., Pullman, WA (United States); Onsager, Terry [National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States); O' Shea, Patrick [Univ. of Maryland, College Park, MD (United States)

2015-09-01

Since the 1950s, scientists and engineers in the U.S. and around the world have worked hard to make an elusive goal to be achieved on Earth: harnessing the reaction that fuels the stars, namely fusion. Practical fusion would be a source of energy that is unlimited, safe, environmentally benign, available to all nations and not dependent on climate or the whims of the weather. Significant resources, most notably from the U.S. Department of Energy (DOE) Office of Fusion Energy Sciences (FES), have been devoted to pursuing that dream, and significant progress is being made in turning it into a reality. However, that is only part of the story. The process of creating a fusion-based energy supply on Earth has led to technological and scientific achievements of far-reaching impact that touch every aspect of our lives. Those largely unanticipated advances, spanning a wide variety of fields in science and technology, are the focus of this report. There are many synergies between research in plasma physics (the study of charged particles and fluids interacting with self-consistent electric and magnetic fields), high-energy physics, and condensed matter physics dating back many decades. For instance, the formulation of a mathematical theory of solitons, solitary waves which are seen in everything from plasmas to water waves to Bose-Einstein Condensates, has led to an equal span of applications, including the fields of optics, fluid mechanics and biophysics. Another example, the development of a precise criterion for transition to chaos in Hamiltonian systems, has offered insights into a range of phenomena including planetary orbits, two-person games and changes in the weather. Seven distinct areas of fusion energy sciences were identified and reviewed which have had a recent impact on fields of science, technology and engineering not directly associated with fusion energy: Basic plasma science; Low temperature plasmas; Space and astrophysical plasmas; High energy density

Energy from inertial fusion

International Nuclear Information System (INIS)

1995-03-01

This book contains 22 articles on inertial fusion energy (IFE) research and development written in the framework of an international collaboration of authors under the guidance of an advisory group on inertial fusion energy set up in 1991 to advise the IAEA. It describes the actual scientific, engineering and technological developments in the field of inertial confinement fusion (ICF). It also identifies ways in which international co-operation in ICF could be stimulated. The book is intended for a large audience and provides an introduction to inertial fusion energy and an overview of the various technologies needed for IFE power plants to be developed. It contains chapters on (i) the fundamentals of IFE; (ii) inertial confinement target physics; (iii) IFE power plant design principles (requirements for power plant drivers, solid state laser drivers, gas laser drivers, heavy ion drivers, and light ion drivers, target fabrication and positioning, reaction chamber systems, power generation and conditioning and radiation control, materials management and target materials recovery), (iv) special design issues (radiation damage in structural materials, induced radioactivity, laser driver- reaction chamber interfaces, ion beam driver-reaction chamber interfaces), (v) inertial fusion energy development strategy, (vi) safety and environmental impact, (vii) economics and other figures of merit; (viii) other uses of inertial fusion (both those involving and not involving implosions); and (ix) international activities. Refs, figs and tabs

Inertial fusion energy

International Nuclear Information System (INIS)

Decroisette, M.; Andre, M.; Bayer, C.; Juraszek, D.; Le Garrec, B.; Deutsch, C.; Migus, A.

2005-01-01

We first recall the scientific basis of inertial fusion and then describe a generic fusion reactor with the different components: the driver, the fusion chamber, the material treatment unit, the target factory and the turbines. We analyse the options proposed at the present time for the driver and for target irradiation scheme giving the state of art for each approach. We conclude by the presentation of LMJ (laser Megajoule) and NIF (national ignition facility) projects. These facilities aim to demonstrate the feasibility of laboratory DT ignition, first step toward Inertial Fusion Energy. (authors)

Social assessment on fusion energy technology

International Nuclear Information System (INIS)

Nemoto, Kazuyasu

1981-01-01

In regard to the research and development for fusion energy technologies which are still in the stage of demonstrating scientific availability, it is necessary to accumulate the demonstrations of economic and environmental availability through the demonstration of technological availability. The purpose of this report is to examine how the society can utilize the new fusion energy technology. The technical characteristics of fusion energy system were analyzed in two aspects, namely the production techniques of thermal energy and electric energy. Also on the social characteristics in the fuel cycle stage of fusion reactors, the comparative analysis with existing fission reactors was carried out. Then, prediction and evaluation were made what change of social cycle fusion power generation causes on the social system formalized as a socio-ecological model. Moreover, the restricting factors to be the institutional obstacles to the application of fusion energy system to the society were analyzed from three levels of the decision making on energy policy. Since the convertor of fusion energy system is steam power generation system similar to existing system, the contents and properties of the social cycle change in the American society to which such new energy technology is applied are not much different even if the conversion will be made in future. (Kako, I.)

The economic value of fusion energy

International Nuclear Information System (INIS)

Kim, S.H.; Clarke, J.; Edmonds, J.

1996-01-01

The potential economic benefit of fusion energy technology is significant and could dwarf the world's total expenditure on fusion energy research and development. However, the realization of these benefits will depend on the economic competitiveness of electricity generation from fusion energy technologies relative to that from other existing fossil fueled and renewable technologies, as well as the time in which fusion energy technologies are available for commercial operation. Utilizing the Second Generation Model, a long-term energy/economics model, the potential economic benefit of fusion energy technology for the United States was assessed. Model scenarios with hypothetical fusion power technologies based on the International Thermonuclear Experimental Reactor (ITER) design with varying cost and time of availability showed that significant economic benefit exists from a competitive fusion technology with cost of electricity (COE) of 0.06 $/kWhr and available in the year 2025. The fusion technology with these characteristics resulted in a total discounted GDP benefit of $105 billion from the year 1995 to 2100. On the other hand, uncompetitive fusion technologies with higher COE of 0.12 and 0.09 $/kWhr had little economic benefits. Moreover, delaying the introduction of all fusion technologies from 2025 to 2050 reduced the economic benefits of fusion technologies by more than 60 percent. Aside from the economic benefit of fusion technologies operating in the United States, the potential economic value of international trade in fusion technologies is likely to be even greater. If the United States could capture just a portion of the global electricity market, the export value of the fusion technology could amount to hundreds of billions of dollars, whereas the cost of importing the technology to the United States will erase any benefits derived from GDP increases

Evaluation of the energy required for constructing and operating a fusion power plant

International Nuclear Information System (INIS)

Buende, R.

1982-09-01

The energy required for constructing and operating a tokamak fusion power plant is appraised with respect to the energy output during the lifetime of the plant. A harvesting factor is deduced as a relevant figure of energetic merit and is used for a comparison between fusion, fission, and coal-fired power plants. Because fusion power plants involve considerable uncertainties the comparison is supplemented by a sensitivity analysis. In comparison with Light Water Reactor plants fusion power plants appear to be rather favourable in this respect. The energy required for providing the fuel is relatively low for fusion plants, thus overcompensating the considerable higher amount of energy necessary for constructing the fusion power plant. (orig.)

Systematic continuum-discretized coupled-channels calculations of total fusion for 6Li with targets 28Si, 59Co, 96Zr, 198Pt, and 209Bi: Effect of resonance states

Science.gov (United States)

Gómez Camacho, A.; Wang, Bing; Zhang, H. Q.

2018-05-01

Continuum discretized coupled-channel (CDCC) calculations of total fusion cross sections for reactions induced by the weakly bound nucleus 6Li with targets 28Si, 59Co, 96Zr, 198Pt, and 209Bi at energies around the Coulomb barrier are presented. In the cluster structure frame of 6Li→α +d , short-range absorption potentials are considered for the interactions between the α and d fragments with the targets. The effect of resonance (l =2 , Jπ=3+,2+,1+ ) and nonresonance states of 6Li on fusion is studied by using two approaches: (1) by omitting the resonance states from the full discretized CDCC breakup space and (2) by considering only the resonance subspace. A systematic analysis of the effect on fusion from resonance breakup couplings is carried out from light to heavy mass targets. Among other things, it is found that resonance breakup states produce strong repulsive polarization potentials that lead to fusion suppression. Couplings from nonresonance states give place to weak repulsive potentials at high energies; however, these become attractive for the heavier targets at low energies.

HEDP and new directions for fusion energy

Science.gov (United States)

Kirkpatrick, Ronald C.

2010-06-01

Magnetic-confinement fusion energy and inertia-confinement fusion energy (IFE) represent two extreme approaches to the quest for the application of thermonuclear fusion to electrical energy generation. Blind pursuit of these extreme approaches has long delayed the achievement of their common goal. We point out the possibility of an intermediate approach that promises cheaper, and consequently more rapid development of fusion energy. For example, magneto-inertial fusion appears to be possible over a broad range of parameter space. It is further argued that imposition of artificial constraints impedes the discovery of physics solutions for the fusion energy problem.

Ch. 37, Inertial Fusion Energy Technology

International Nuclear Information System (INIS)

Moses, E.

2010-01-01

Nuclear fission, nuclear fusion, and renewable energy (including biofuels) are the only energy sources capable of satisfying the Earth's need for power for the next century and beyond without the negative environmental impacts of fossil fuels. Substantially increasing the use of nuclear fission and renewable energy now could help reduce dependency on fossil fuels, but nuclear fusion has the potential of becoming the ultimate base-load energy source. Fusion is an attractive fuel source because it is virtually inexhaustible, widely available, and lacks proliferation concerns. It also has a greatly reduced waste impact, and no danger of runaway reactions or meltdowns. The substantial environmental, commercial, and security benefits of fusion continue to motivate the research needed to make fusion power a reality. Replicating the fusion reactions that power the sun and stars to meet Earth's energy needs has been a long-sought scientific and engineering challenge. In fact, this technological challenge is arguably the most difficult ever undertaken. Even after roughly 60 years of worldwide research, much more remains to be learned. the magnitude of the task has caused some to declare that fusion is 20 years away, and always will be. This glib criticism ignores the enormous progress that has occurred during those decades, progress inboth scientific understanding and essential technologies that has enabled experiments producing significant amounts of fusion energy. For example, more than 15 megawatts of fusion power was produced in a pulse of about half a second. Practical fusion power plants will need to produce higher powers averaged over much longer periods of time. In addition, the most efficient experiments to date have required using about 50% more energy than the resulting fusion reaction generated. That is, there was no net energy gain, which is essential if fusion energy is to be a viable source of electricity. The simplest fusion fuels, the heavy isotopes of

76 FR 49757 - Fusion Energy Sciences Advisory Committee

Science.gov (United States)

2011-08-11

... DEPARTMENT OF ENERGY Fusion Energy Sciences Advisory Committee AGENCY: Office of Science... Services Administration, notice is hereby given that the Fusion Energy Sciences Advisory Committee will be... science, fusion science, and fusion technology related to the Fusion Energy Sciences program. Additionally...

EURATOM strategy towards fusion energy

International Nuclear Information System (INIS)

Varandas, C.

2007-01-01

Research and development (Research and Development) activities in controlled thermonuclear fusion have been carried out since the 60's of the last century aiming at providing a new clean, powerful, practically inexhaustive, safe, environmentally friend and economically attractive energy source for the sustainable development of our society.The EURATOM Fusion Programme (EFP) has the leadership of the magnetic confinement Research and Development activities due to the excellent results obtained on JET and other specialized devices, such as ASDEX-Upgrade, TORE SUPRA, FTU, TCV, TEXTOR, CASTOR, ISTTOK, MAST, TJ-II, W7-X, RFX and EXTRAP. JET is the largest tokamak in operation and the single device that can use deuterium and tritium mixes. It has produced 16 MW of fusion power, during 3 seconds, with an energy amplification of 0.6. The next steps of the EFP strategy towards fusion energy are ITER complemented by a vigorous Accompanying Programme, DEMO and a prototype of a fusion power plant. ITER, the first experimental fusion reactor, is a large-scale project (35-year duration, 10000 MEuros budget), developed in the frame of a very broad international collaboration, involving EURATOM, Japan, Russia Federation, United States of America, Korea, China and India. ITER has two main objectives: (i) to prove the scientific and technical viability of fusion energy by producing 500 MW, during 300 seconds and a energy amplification between 10 and 20; and (ii) to test the simultaneous and integrated operation of the technologies needed for a fusion reactor. The Accompanying Programme aims to prepare the ITER scientific exploitation and the DEMO design, including the development of the International Fusion Materials Irradiation Facility (IFMIF). A substantial part of this programme will be carried out in the frame of the Broader Approach, an agreement signed by EURATOM and Japan. The main goal of DEMO is to produce electricity, during a long time, from nuclear fusion reactions. The

Fusion energy

International Nuclear Information System (INIS)

Anon.

1979-01-01

The efforts of the Chemical Technology Division in fusion energy include the areas of fuel handling, processing, and containment. Current studies are concerned largely with the development of vacuum pumps for fusion reactors and experiments and with development and evaluation of techniques for recovering tritium from solid or liquid breeding blankets. In addition, a small effort is devoted to support of the ORNL design of a major Tokamak experiment, The Next Step (TNS)

Magnetic fusion energy. Progress report, January--June 1976

International Nuclear Information System (INIS)

Doran, D.G.; Yoshikawa, H.H.

1976-01-01

Brief descriptions are given of progress in the Irradiation Effects Analysis and Mechanical Performance of Magnetic Fusion Energy (MFE) Materials programs and in related programs. The objective of the Irradiation Effects Analysis program is the correlation of effects produced in neutron and charged particle irradiations in order to apply them to fusion reactor environments. Low energy displacement cascades--of intrinsic interest and the least understood component of high energy cascades--are being simulated by computer codes of the dynamical (D), quasi-dynamical (Q-D), and binary collision (BC) types. Fair agreement has been found between D and Q-D for low index focused replacement sequences; substantial differences appeared for a 250 eV high index event. The objective of the Mechanical Performance of MFE Materials program is to establish the effects of fusion reactor irradiation environments on the mechanical properties of candidate first wall materials. A Precision Torsional Creep Apparatus is being developed to permit accelerator studies of irradiation creep and behavior under cyclic conditions. This apparatus has demonstrated the required strain sensitivity, stress control, and thermal stability for long term thermal testing, and that it can be used for cyclic testing

Fusion with projectiles from carbon to argon at energies between 20A MeV and 60A MeV

International Nuclear Information System (INIS)

Galin, J.

1986-01-01

Fusion reactions are known to be the dominant reaction channel at low bombarding energies and can now be investigated with a large variety of projectiles at several tens of MeV per nucleon. The gross characteristics of the fusion process can be studied by measuring global quantities, such as the linear momentum transferred from projectile to target and the dissipated energy of the reaction. The strong correlation between these two quantities is demonstrated at moderate bombarding energies, with a Ne projectile on a U target. It is expected that light particle (charged or neutron) multiplicity measurements can be extended to this higher energy domain and be used to selectively filter these collisions, according to their degree of violence. A review of the linear momentum transfer is made, considering essentially heavy targets and two important parameters in the entrance channel: the projectile energy and its mass. Over a broad mass range, and for energies up to 30A MeV, the momentum transfer scales with the mass of the projectile. At 30A MeV, the most probable value of projectile momentum transferred to the fused system is 80%, and this represents roughly 180 MeV/c per projectile nucleon. At higher bombarding energies, the momentum distribution in the fused systems, as observed from binary fission events, seems to depend on the mass of the projectile. Further studies are still needed to understand this behavior. Finally, the decay of highly excited (E* similarly ordered 500-800 MeV) fused systems, with masses close to 270 amu, is studied from the characteristics of both fusion fragments and light charged particles. It is shown that thermal equilibrium is reached before fission, even for such high energy deposition. However, the decay sequence is sensitive to dynamical effects and does not depend only on available phase space

Observed side feeding in incomplete fusion dynamics in 16O + 160Gd reaction at energy ∼5.6 MeV/A: Spin distribution measurements

Science.gov (United States)

Ali, Rahbar; Afzal Ansari, M.; Singh, D.; Kumar, Rakesh; Singh, D. P.; Sharma, M. K.; Gupta, Unnati; Singh, B. P.; Shidling, P. D.; Negi, Dinesh; Muralithar, S.; Singh, R. P.; Bhowmik, R. K.

2017-12-01

Spin distributions of various residues populated via complete fusion (CF) and incomplete fusion (ICF) reactions in the interaction of 16O with 160Gd at the projectile energy Eproj ∼ 5.6 MeV/A have been studied. The experimentally measured spin distributions of the residues associated with the ICF reactions are found to be distinctly different from those populated via the CF reactions. An attempt has been made to extract the side-feeding pattern from the spin distributions of CF and ICF reaction products. It has been observed that the CF products are strongly fed over a broad spin range. But, no side-feeding takes place in the low observed spins as low partial waves are strongly hindered in the fast α-emission channels (associated with ICF) in the forward direction. It has also been observed that the mean input angular momentum for direct α-emitting (ICF) channels is relatively higher than evaporation α-emitting (CF) channels, and it increases with direct α-multiplicity in forward direction.

Accelerated plan to develop magnetic fusion energy

International Nuclear Information System (INIS)

Fowler, T.K.

1986-01-01

We have shown that, despite funding delays since the passage of the Magnetic Fusion Engineering Act of 1980, fusion development could still be carried to the point of a demonstration plant by the year 2000 as called for in the Act if funding, now about $365 million per year, were increased to the $1 billion range over the next few years (see Table I). We have also suggested that there may be an economic incentive for the private sector to become in accelerating fusion development on account of the greater stability of energy production costs from fusion. Namely, whereas fossil fuel prices will surely escalate in the course of time, fusion fuel will always be abundantly available at low cost; and fusion technology poses less future risk to the public and the investor compared to conventional nuclear power. In short, once a fusion plant is built, the cost of generating electricity mainly the amortization of the plant capital cost - would be relatively fixed for the life of the plant. In Sec. V, we found that the projected capital cost of fusion plants ($2000 to $4000 per KW/sub e/) would probably be acceptable if fusion plants were available today

Direct energy conversion for IEC fusion for space applications

International Nuclear Information System (INIS)

Momota, Hiromu; Nadler, Jon; Miley, George H.

2000-08-01

The paper describes a concept of extracting fusion power from D- 3 He fueled IEC (Inertia Electrostatic Configuration) devices. The fusion system consists of a series of fusion modules and direct energy converters at an end or at both ends. This system of multiple units is linear and is connected by a magnetic field. A pair of coils anti-parallel to the magnetic field yields a field-null domain at the center of each unit as required for IEC operation. A stabilizing coil installed between the coil pairs eliminates the strong attractive force between the anti-parallel coils. Accessible regions for charged particle trajectories are essentially isolated from the coil structure. Thus, charged particles are directed along magnetic field lines to the direct energy converter without appreciable losses. A direct energy converter unit designed to be compatible to this unique system is also described. It basically consists of a separator and a traveling wave converter. A separator separates low energy ions and electron from the 14.7 MeV fusion protons and then converts their energy into electricity. In the traveling wave direct energy converter, fusion protons are modulated to form bunches. It couples with a transmission line to couple AC power out. The overall conversion efficiency of this system, combined with E- 3 He IEC cores, is estimated as high as 60%. (author)

Direct energy conversion for IEC fusion for space applications

Energy Technology Data Exchange (ETDEWEB)

Momota, Hiromu; Nadler, Jon [National Inst. for Fusion Science, Toki, Gifu (Japan); Miley, George H. [Fusion Studies Laboratory, Urbana, IL (United States)

2000-08-01

The paper describes a concept of extracting fusion power from D-{sup 3}He fueled IEC (Inertia Electrostatic Configuration) devices. The fusion system consists of a series of fusion modules and direct energy converters at an end or at both ends. This system of multiple units is linear and is connected by a magnetic field. A pair of coils anti-parallel to the magnetic field yields a field-null domain at the center of each unit as required for IEC operation. A stabilizing coil installed between the coil pairs eliminates the strong attractive force between the anti-parallel coils. Accessible regions for charged particle trajectories are essentially isolated from the coil structure. Thus, charged particles are directed along magnetic field lines to the direct energy converter without appreciable losses. A direct energy converter unit designed to be compatible to this unique system is also described. It basically consists of a separator and a traveling wave converter. A separator separates low energy ions and electron from the 14.7 MeV fusion protons and then converts their energy into electricity. In the traveling wave direct energy converter, fusion protons are modulated to form bunches. It couples with a transmission line to couple AC power out. The overall conversion efficiency of this system, combined with E-{sup 3}He IEC cores, is estimated as high as 60%. (author)

Sausage instability of Z-discharged plasma channel in LIB-fusion device

International Nuclear Information System (INIS)

Murakami, H.; Kawata, S.; Niu, K.

1982-07-01

Current-carring plasma channels have been proposed for transporting intense ion beams from diodes to a target in a LIB-fusion device. In this paper, the growth rate of the most dangerous surface mode, that is, axisymmetric sausage instability is examined for the plasma channel. The growth rate is shown to be smaller than that of the plasma channel with no fluid motion in a sharp boundary. It is concluded that the stable plasma channel can be formed. (author)

Inertial Fusion Energy

Energy Technology Data Exchange (ETDEWEB)

Mima, K

2012-09-15

In 1917, Albert Einstein suggested the theory of stimulated emission of light that led to the development of the laser. The first laser, based on Einstein's theory, was demonstrated by the Maiman experiment in 1960. In association with the invention and developments of the laser, N.G. Basov, A. Prokorov and C.H. Towns received the Nobel prize for physics in 1963. On the other hand, it had been recognized that nuclear fusion energy is the energy source of our universe. It is the origin of the energy in our sun and in the stars. Right after the laser oscillation experiment, it was suggested by J. Nuckolls, E. Teller and S. Colgate in the USA and A. Sakharov in the USSR that nuclear fusion induced by lasers be used to solve the energy problem. Following the suggestion, the pioneering works for heating plasmas to a thermonuclear temperature with a laser were published by N. Basov, O.N. Krohin, J.M. Dawson, C.R. Kastler, H. Hora, F. Flux and S. Eliezer. The new concept of fusion ignition and burn by laser 'implosion' was proposed by J. Nuckolls, which extended the spherically imploding shock concept discovered by G. Guderley to the laser fusion concept. Since then, laser fusion research has started all over the world. For example, many inertial fusion energy (IFE) facilities have been constructed for investigating implosion physics: Lasers: GEKKO I, GEKKO II, GEKKO IV, GEKKO MII and GEKKO xII at ILE, Osaka University, Japan; JANUS, CYCLOPS, ARUGUS, SHIVA and NOVA at Lawrence Livermore National Laboratory (LLNL), USA; OMEGA at the Laboratory for Laser Energetics (LLE), University of Rochester, USA; PHEBUS at Limeil, Paris, France; the ASTERIx iodine laser at the Max-Planck-Institut fuer Plasmaphysik (IPP), Garching, Germany; MPI, GLECO at the Laboratoire d'Utilisation des Lasers Intenses (LULI), ecole Polytecnique, France; HELIOS at Los Alamos National Laboratory, USA; Shengan II at the Shanghai Institute of Optics and Fine Mechanics, China; VULCAN at the Rutherford

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

Direct conversion of fusion energy

International Nuclear Information System (INIS)

Johansson, Markus

2003-03-01

Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D- 3 He reaction and the p- 11 B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger βB 2 0 to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high β values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D- 3 He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D 3 He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D 3 He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion or liquid metal MHD conversion (LMMHD). For a D

Direct conversion of fusion energy

Energy Technology Data Exchange (ETDEWEB)

Johansson, Markus

2003-03-01

Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D-{sup 3}He reaction and the p-{sup 11}B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger {beta}B{sup 2}{sub 0} to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high {beta} values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D-{sup 3}He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D{sub 3} He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D{sub 3} He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion

Dynamics of complete and incomplete fusion of 6,7Li, 15N and 16O with a 209Bi target

International Nuclear Information System (INIS)

Gautam, Manjeet Singh; Vinod, K.; Khatri, Hitender

2017-01-01

The dynamics of complete and incomplete fusion of 6,7 Li, 15 N and 16 O with a common target ( 209 Bi) around the Coulomb barrier are analyzed within the context of the coupled channel formulation and the energy dependent Woods-Saxon potential (EDWSP) model. The calculated results are compared with experimental fusion cross-sections and it has been shown that complete fusion (CF) data of weakly bound projectile with a heavy target ( 209 Bi) gets suppressed at above barrier energies. In the case of the 6 Li + 209 Bi ( 7 Li + 209 Bi) reaction, the CF data at above barrier energies is reduced by 34% (26%) with reference to the expectations of the coupled channel approach. However, the theoretical estimations due to the EDWSP model can minimize the suppression factor by 9% with respect to the reported value and consequently the portion of above barrier CF cross-section data of 6 Li + 209 Bi ( 7 Li + 209 Bi) reaction is suppressed by 25% (17%) when compared with the present model calculations. This fusion inhibition can be correlated with the low breakup threshold of projectile which in turn breaks up into two fragments in the entrance channel prior to fusion barrier. The total fusion (TF) data, which is sum of complete fusion (CF) data and incomplete fusion (ICF) data, is not suppressed when compared with the predictions of the theoretical approaches and thus breakup channel has very little influence on the total fusion cross-sections. Although the breakup fragments appeared in both reactions, the enhanced suppression effects observed for the lighter projectile can be correlated with its low binding energy associated with the α-breakup channel. Further the outcomes of the EDWSP model reasonably explained the ICF contribution appeared in the fusion of 6,7 Li + 209 Bi reactions. In contrast to this, the observed fusion dynamics of 15 N + 209 Bi and 16 O + 209 Bi reactions, wherein the collective excitations such as two phonon, three phonon vibrational states contribute

Recent experimental results in sub- and near-barrier heavy-ion fusion reactions

Energy Technology Data Exchange (ETDEWEB)

Montagnoli, Giovanna [Dipartimento di Fisica e Astronomia, Universita di Padova (Italy); INFN Sezione di Padova (Italy); Stefanini, Alberto M. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy)

2017-08-15

Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus is mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations overpredict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars. (orig.)

Need for research and development in fusion: Economical energy for a sustainable future with low environmental impact

International Nuclear Information System (INIS)

Logan, B.G.; Perkins, L.J.; Moir, R.W.; Ryutov, D.D.

1995-01-01

Fusion, advanced fission, and solar-electric plants are the only unlimited nonfossil options for a sustainable energy future for the world. Fusion poses the only indigenous fuel reserve that will last as long as the earth itself lasts. However, continued innovation and diversity in fusion R ampersand D will be required to meet its economic goal. The long-term nature of fusion research means that the required R ampersand D investment will not come from the private sector. However, once fusion is realized commercially, the dividend for humanity will be profound in terms of the welfare of the global community. We should also not underestimate the huge potential export opportunities that would then open up for industry. Federal energy R ampersand D at nearly 1% of U.S. energy costs is prudent and justified to allow pursuit of all three primary energy options for a sustainable energy future. Multiple parallel paths are essential to ensure success. The projected timescale for significant shortfalls in world energy supply to become apparent is nearly 30 to 40 yr depending on assumptions. The time to develop fusion from near-term R ampersand D through significant commercial market penetration is at least of the same order, so its development must not be delayed. 6 refs., 2 figs

Fusion-fission of superheavy nuclei at low excitation energies

International Nuclear Information System (INIS)

Itkis, M.G.; Oganesyan, Yu.Ts.; Kozulin, E.M.

2000-01-01

The process of fusion-fission of superheavy nuclei with Z = 102 -122 formed in the reactions with 22 Ne, 26 Mg, 48 Ca, 58 Fe and 86 Kr ions at energies near and below the Coulomb barrier has been studied. The experiments were carried out at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR) using a time-of-flight spectrometer of fission fragments CORSET and a neutron multi-detector DEMON. As a result of the experiments, mass and energy distributions of fission fragments, fission and quasi-fission cross sections, multiplicities of neutrons and gamma-rays and their dependence on the mechanism of formation and decay of compound superheavy systems have been studied

Economic effect of fusion in energy market. Economic impact of fusion deployment in energy market

International Nuclear Information System (INIS)

Konishi, Satoshi

2002-01-01

Energy model analysis estimates the significant contribution of fusion in the latter half of the century under the global environment constraints if it will be successfully developed and introduced into the market. The total possible economical impact of fusion is investigated from the aspect of energy cost savings, sales, and its effects on Gross Domestic Products. Considerable economical possibility will be found in the markets for fusion related devices, of currently developing countries, and for synthesized fuel. The value of fusion development could be evaluated from these possible economic impact in comparison with its necessary investment. (author)

21. IAEA fusion energy conference. Book of abstracts

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

Recognizing the prominent role that nuclear energy plays in the world, and based on the expectation that nuclear fusion will be able to provide an abundant source of energy, the International Atomic Energy Agency (IAEA) supports the exchange of scientific and technical information on fusion research through conferences, meetings and projects. The 21st IAEA Fusion Energy Conference (FEC 2006) provided a forum for presenting and discussing the progress that is being made in fusion experiments, theory and technological developments. It is expected that the progress in the establishment of ITER since the last Fusion Energy Conference will put more emphasis on the physics and technology R and D aspects in the realization of fusion as a clean and lasting energy source. FEC 2006 covered the following topics: OV Overviews; EX Magnetic Confinement Experiments; TH Magnetic Confinement Theory and Modelling; IT ITER Activities; IF Inertial Fusion Experiments and Theory; IC Innovative Concepts; FT Fusion Technology and Power Plant Design; SE Safety, Environmental and Economic Aspects of Fusion. At the same time, a series of satellite meetings and fusion related exhibitions took place.

Fusion the energy of the universe

CERN Document Server

McCracken, Garry

2012-01-01

Fusion: The Energy of the Universe, 2e is an essential reference providing basic principles of fusion energy from its history to the issues and realities progressing from the present day energy crisis. The book provides detailed developments and applications for researchers entering the field of fusion energy research. This second edition includes the latest results from the National Ignition Facility at the Lawrence Radiation Laboratory at Livermore, CA, and the progress on the International Thermonuclear Experimental Reactor (ITER) tokamak programme at Caderache, France.

The fusion-hydrogen energy system

International Nuclear Information System (INIS)

Williams, L.O.

1994-01-01

This paper will describe the structure of the system, from energy generation and hydrogen production through distribution to the end users. It will show how stationary energy users will convert to hydrogen and will outline ancillary uses of hydrogen to aid in reducing other forms of pollution. It will show that the adoption of the fusion hydrogen energy system will facilitate the use of renewable energy such as wind and solar. The development of highly efficient fuel cells for production of electricity near the user and for transportation will be outlined. The safety of the hydrogen fusion energy system is addressed. This paper will show that the combination of fusion generation combined with hydrogen distribution will provide a system capable of virtually eliminating the negative impact on the environment from the use of energy by humanity. In addition, implementation of the energy system will provide techniques and tools that can ameliorate environmental problems unrelated to energy use. (Author)

World progress toward fusion energy

International Nuclear Information System (INIS)

Clarke, J.F.

1989-09-01

This paper will describe the progress in fusion science and technology from a world perspective. The paper will cover the current technical status, including the understanding of fusion's economic, environmental, and safety characteristics. Fusion experiments are approaching the energy breakeven condition. An energy gain (Q) of 30 percent has been achieved in magnetic confinement experiments. In addition, temperatures required for an ignited plasma (Ti = 32 KeV) and energy confinements about 75 percent of that required for ignition have been achieved in separate experiments. Two major facilities have started the experimental campaign to extend these results and achieve or exceed Q = 1 plasma conditions by 1990. Inertial confinement fusion experiments are also approaching thermonuclear conditions and have achieved a compression factor 100-200 times liquid D-T. Because of this progress, the emphasis in fusion research is turning toward questions of engineering feasibility. Leaders of the major fusion R and D programs in the European Community (EC), Japan, the United States, and the U.S.S.R. have agreed on the major steps that are needed to reach the point at which a practical fusion system can be designed. The United States is preparing for an experiment to address the last unexplored scientific issue, the physics of an ignited plasma, during the late 1990's. The EC, Japan, U.S.S.R., and the United States have joined together under the auspices of the International Atomic Energy Agency (IAEA) to jointly design and prepare the validating R and D for an international facility, the International Thermonuclear Experimental Reactor (ITER), to address all the remaining scientific issues and to explore the engineering technology of fusion around the turn of the century. In addition, a network of international agreements have been concluded between these major parties and a number of smaller fusion programs, to cooperate on resolving a complete spectrum of fusion science and

Magnetic-fusion energy and computers

International Nuclear Information System (INIS)

Killeen, J.

1982-01-01

The application of computers to magnetic fusion energy research is essential. In the last several years the use of computers in the numerical modeling of fusion systems has increased substantially. There are several categories of computer models used to study the physics of magnetically confined plasmas. A comparable number of types of models for engineering studies are also in use. To meet the needs of the fusion program, the National Magnetic Fusion Energy Computer Center has been established at the Lawrence Livermore National Laboratory. A large central computing facility is linked to smaller computer centers at each of the major MFE laboratories by a communication network. In addition to providing cost effective computing services, the NMFECC environment stimulates collaboration and the sharing of computer codes among the various fusion research groups

Magnetic fusion energy and computers

International Nuclear Information System (INIS)

Killeen, J.

1982-01-01

The application of computers to magnetic fusion energy research is essential. In the last several years the use of computers in the numerical modeling of fusion systems has increased substantially. There are several categories of computer models used to study the physics of magnetically confined plasmas. A comparable number of types of models for engineering studies are also in use. To meet the needs of the fusion program, the National Magnetic Fusion Energy Computer Center has been established at the Lawrence Livermore National Laboratory. A large central computing facility is linked to smaller computer centers at each of the major MFE laboratories by a communication network. In addition to providing cost effective computing services, the NMFECC environment stimulates collaboration and the sharing of computer codes among the various fusion research groups

Z-Pinch Fusion for Energy Applications

Energy Technology Data Exchange (ETDEWEB)

SPIELMAN,RICK B.

2000-01-01

Z pinches, the oldest fusion concept, have recently been revisited in light of significant advances in the fields of plasma physics and pulsed power engineering. The possibility exists for z-pinch fusion to play a role in commercial energy applications. We report on work to develop z-pinch fusion concepts, the result of an extensive literature search, and the output for a congressionally-mandated workshop on fusion energy held in Snowmass, Co July 11-23,1999.

Z-Pinch Fusion for Energy Applications

International Nuclear Information System (INIS)

SPIELMAN, RICK B.

2000-01-01

Z pinches, the oldest fusion concept, have recently been revisited in light of significant advances in the fields of plasma physics and pulsed power engineering. The possibility exists for z-pinch fusion to play a role in commercial energy applications. We report on work to develop z-pinch fusion concepts, the result of an extensive literature search, and the output for a congressionally-mandated workshop on fusion energy held in Snowmass, Co July 11-23,1999

Neutronics issues and inertial fusion energy: a summary of findings

International Nuclear Information System (INIS)

Latkowski, J.F.

1998-01-01

We have analyzed and compared five major inertial fusion energy (IFE) and two representative magnetic fusion energy (MFE) power plant designs for their environment, safety, and health (ES ampersand H) characteristics. Our work has focussed upon the neutronics of each of the designs and the resulting radiological hazard indices. The calculation of a consistent set of hazard indices allows comparisons to be made between the designs. Such comparisons enable identification of trends in fusion ES ampersand H characteristics and may be used to increase the likelihood of fusion achieving its full potential with respect to ES ampersand H characteristics. The present work summarizes our findings and conclusions. This work emphasizes the need for more research in low-activation materials and for the experimental measurement of radionuclide release fractions under accident conditions

ITER and the road map towards fusion energy

International Nuclear Information System (INIS)

Tran, M.Q.

2005-01-01

Outlined is a fusion as a sustainable energy, the conditions and challenges for the realisation of fusion energy. Given is electricity generating power plant conceptual study and the rule of fusion energy in future energy scenarios

Challenges and the future of the fusion energy

International Nuclear Information System (INIS)

Gross, R.A.

1982-01-01

The need to develop new large energy resources is discussed. One of three inexhaustible energy resource possibilities is fusion energy, whose history and scientific goals are described. The current world-wide research and development program for fusion is outlined. As an example of today's perception of what fusion energy will be like, a commercial tokamak fusion electric powerplant is described. Special attention is devoted to some of the challenging material problems that face fusion power development. (Author) [pt

High spin spectroscopy near the N=Z line: Channel selection and excitation energy systematics

Energy Technology Data Exchange (ETDEWEB)

Svensson, C.E.; Cameron, J.A.; Flibotte, S. [McMaster Univ., Ontario (Canada)] [and others

1996-12-31

The total {gamma}-ray and charged-particle energies emitted in fusion-evaporation reactions leading to N=Z compound systems in the A = 50-70 mass region have been measured with the 8{pi} {gamma}-ray spectrometer and the miniball charged-particle detector array. A new method of channel selection has been developed which combines particle identification with these total energy measurements and greatly improves upon the selectivity possible with particle detection alone. In addition, the event by event measurement of total {gamma}-ray energies using the BGO ball of the 8{pi} spectrometer has allowed a determination of excitation energies following particle evaporation for a large number of channels in several different reactions. The new channel selection procedure and excitation energy systematics are illustrated with data from the reaction of {sup 24}Mg on {sup 40}Ca at E{sub lab} = 80MeV.

Color-to-grayscale conversion through weighted multiresolution channel fusion

NARCIS (Netherlands)

Wu, T.; Toet, A.

2014-01-01

We present a color-to-gray conversion algorithm that retains both the overall appearance and the discriminability of details of the input color image. The algorithm employs a weighted pyramid image fusion scheme to blend the R, G, and B color channels of the input image into a single grayscale

Proton channeling in Au at low energies; Canalizacion de protones en Au a bajas energias

Energy Technology Data Exchange (ETDEWEB)

Valdes, J E; Vargas, P [Chile Univ., Santiago (Chile). Dept. de Fisica

1997-12-31

The electronic energy loss for low velocity protons channeled in the <100> direction single crystal Au is calculated. The spatial distribution of valence electronic density in Au is calculated using Tight Binding Linear Muffin Tin Method. The proton trajectories are determined by numerical integration of the classical motion equation, and the energy loss is evaluated using the calculated valence electronic density in the friction term. The results allow to describe qualitatively the non linear behavior of energy loss with ion velocity observed experimentally. (author). 14 refs., 4 figs.

Fusion power in a future low carbon global electricity system

DEFF Research Database (Denmark)

Cabal, H.; Lechón, Y.; Bustreo, C.

2017-01-01

Fusion is one of the technologies that may contribute to a future, low carbon, global energy supply system. In this article we investigate the role that it may play under different scenarios. The global energy model ETM (originally EFDA TIMES Model) has been used to analyse the participation...

Magnetic fusion energy. Part VI

International Nuclear Information System (INIS)

Anon.

1982-01-01

The first chapter of this part describes briefly the DOE policy for fusion energy. Subsequent chapters include: FY 1980 overview - activities of the Office of Fusion Energy; subactivity descriptions (confinement systems, development and technology, applied plasma physics, and reactor projects); field activities (DOE laboratories, educational institutions, nonprofit organizations, and commercial firms); commercialization; environmental implications; regional activities; and international programs

World progress toward fusion energy

International Nuclear Information System (INIS)

Davies, N.A.

1989-01-01

The author discusses international progress in fusion research during the last three years. Much of the technical progress has been achieved through international collaboration in magnetic fusion research. This progress has stimulated political interest in a multinational effort, aimed at designing and possibly constructing the world's first experimental fusion reactor. This interest was reflected in recent summit-level discussions involving President Mitterand, General Secretary Gorbachev, and President Reagan. Most recently, the European Community (EC), Japan, the United States, and the U.S.S.R. have decided to begin serious preparation for taking the next step toward practical fusion energy. These parties have agreed to begin the design and supporting R and D for an International Thermonuclear Experimental Reactor (ITER) under the auspices of the International Atomic Energy Agency (IAEA). The initiation of this international program to prepare for a fusion test reactor is discussed

Fusion energy research for ITER and beyond

International Nuclear Information System (INIS)

Romanelli, Francesco; Laxaaback, Martin

2011-01-01

The achievement in the last two decades of controlled fusion in the laboratory environment is opening the way to the realization of fusion as a source of sustainable, safe and environmentally responsible energy. The next step towards this goal is the construction of the International Thermonuclear Experimental Reactor (ITER), which aims to demonstrate net fusion energy production on the reactor scale. This paper reviews the current status of magnetic confinement fusion research in view of the ITER project and provides an overview of the main remaining challenges on the way towards the realization of commercial fusion energy production in the second half of this century. (orig.)

Energy balance of controlled thermonuclear fusion

International Nuclear Information System (INIS)

Hashmi, M.; Staudenmaier, G.

2000-01-01

It is shown that a discrepancy and incompatibility persist between basic physics and fusion-literature regarding the radiation losses from a thermonuclear plasma. Whereas the fusion-literature neglects the excitation or line radiation completely, according to basic physics it depends upon the prevailing conditions and cannot be neglected in general. Moreover, for a magnetized plasma, while the fusion-literature assumes a self-absorption or reabsorption of cyclotron or synchrotron radiation emitted by the electrons spiraling along the magnetic field, the basic physics does not allow any effective reabsorption of cyclotron or synchrotron radiation. As is demonstrated, fallacious assumptions and notions, which somehow or other crept into the fusion-literature, are responsible for this discrepancy. In the present work, the theory is corrected. On the grounds of basic physics, a complete energy balance of magnetized and non-magnetized plasmas is presented for pulsed, stationary and self-sustaining operations by taking into account the energy release by reactions of light nuclei as well as different kinds of diffusive (conduction) and radiative (bremsstrahlung, cyclotron or synchrotron radiation and excitation radiation) energy losses. Already the energy losses by radiation make the energy balance negative. Hence, a fusion reactor-an energy producing device-seems to be beyond the realms of realization. (orig.)

On Korean strategy and plan for fusion energy

International Nuclear Information System (INIS)

Kim, H.J.; Choi, W-J.; Park, C.; Kim, H.C.

2012-01-01

In developing KSTAR (Korean Superconducting Tokamak Advanced Research), Korea had initiated a mid-entry strategy to catch up with the technologies required for the development of a fusion reactor, based on the tokamak magnetic confinement concept. Upon joining ITER (International Thermonuclear Experimental Reactor), Korean government enacted a promotional law for the fusion energy development. Under this promotional law the national promotional plans for developing fusion energy have been established. The National Fusion Research Institute (NFRI) developed the strategy and plan for a fusion DEMO program to realize the magnetic fusion energy. (author)

On Korean strategy and plan for fusion energy

Energy Technology Data Exchange (ETDEWEB)

Kim, H.J. [National Fusion Research Inst., Daejeon (Korea, Republic of); Choi, W-J. [Chungnam National Univ., Daejeon (Korea, Republic of); Park, C. [POSTECH, Pohang (Korea, Republic of); Kim, H.C. [National Fusion Research Inst., Daejeon (Korea, Republic of)

2012-07-01

In developing KSTAR (Korean Superconducting Tokamak Advanced Research), Korea had initiated a mid-entry strategy to catch up with the technologies required for the development of a fusion reactor, based on the tokamak magnetic confinement concept. Upon joining ITER (International Thermonuclear Experimental Reactor), Korean government enacted a promotional law for the fusion energy development. Under this promotional law the national promotional plans for developing fusion energy have been established. The National Fusion Research Institute (NFRI) developed the strategy and plan for a fusion DEMO program to realize the magnetic fusion energy. (author)

Fusion energy. What Canada can do

International Nuclear Information System (INIS)

Weller, J.A.

1988-01-01

As Canada's fusion programs have grown, Canadian capabilities in fusion science and technology have grown and matured with them. The fusion capabilities described in this booklet have come from a coordinated national effort. The Government of Canada is committed to continuing its fusion energy program, and to supporting global fusion efforts. These first pages provide an overview of Canada's fusion work and its underlying basis of science and technology

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

Direct energy conversion of radiation energy in fusion reactor

International Nuclear Information System (INIS)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned. (author)

Direct energy conversion of radiation energy in fusion reactor

Science.gov (United States)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned.

Direct energy conversion of radiation energy in fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1993-11-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generates electricity by temperature gradient in conductors. A strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy conversion are mentioned. (author).

Direct energy conversion of radiation energy in fusion reactor

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S. [National Inst. for Fusion Science, Nagoya (Japan); Ohnishi, M.; Onozuka, M.; Uenosono, C.

1994-12-31

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generate electricity by temperature gradient in conductors. A Strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy converter are mentioned. (author).

Direct energy conversion of radiation energy in fusion reactor

International Nuclear Information System (INIS)

Yamaguchi, S.; Iiyoshi, A.; Motojima, O.; Okamoto, M.; Sudo, S.; Ohnishi, M.; Onozuka, M.; Uenosono, C.

1994-01-01

Direct energy conversion from plasma heat flux has been studied. Since major parts of fusion energy in the advanced fusion reactor are radiation and charged particle energies, the flexible design of the blanket is possible. We discuss the potentiality of the thermoelectric element that generate electricity by temperature gradient in conductors. A Strong magnetic field is used to confine the fusion plasma, therefore, it is appropriate to consider the effect of the magnetic field. We propose a new element which is called Nernst element. The new element needs the magnetic field and the temperature gradient. We compare the efficiency of these two elements in a semiconductor model. Finally, a direct energy converter are mentioned. (author)

HEDP and new directions for fusion energy

International Nuclear Information System (INIS)

Kirkpatrick, Ronald C.

2009-01-01

The Quest for fusion energy has a long history and the demonstration of thermonuclear energy release in 1951 represented a record achievement for high energy density. While this first demonstration was in response to the extreme fears of mankind, it also marked the beginning of a great hope that it would usher in an era of boundless cheap energy. In fact, fusion still promises to be an enabling technology that can be compared to the prehistoric utilization of fire. Why has the quest for fusion energy been so long on promises and so short in fulfillment? This paper briefly reviews past approaches to fusion energy and suggests new directions. By putting aside the old thinking and vigorously applying our experimental, computational and theoretical tools developed over the past decades we should be able to make rapid progress toward satisfying an urgent need. Fusion not only holds the key to abundant green energy, but also promises to enable deep space missions and the creation of rare elements and isotopes for wide-ranging industrial applications and medical diagnostics.

Graphite for fusion energy applications

International Nuclear Information System (INIS)

Eatherly, W.P.; Clausing, R.E.; Strehlow, R.A.; Kennedy, C.R.; Mioduszewski, P.K.

1987-03-01

Graphite is in widespread and beneficial use in present fusion energy devices. This report reflects the view of graphite materials scientists on using graphite in fusion devices. Graphite properties are discussed with emphasis on application to fusion reactors. This report is intended to be introductory and descriptive and is not intended to serve as a definitive information source

Heavy-ion fusion: Channel-coupling effects, the barrier penetration model, and the threshold anomaly for heavy-ion potentials

International Nuclear Information System (INIS)

Satchler, G.R.; Nagarajan, M.A.; Lilley, J.S.; Thompson, I.J.

1987-01-01

We study the formal structure of the influence of channel coupling on near- and sub-barrier fusion. The reduction to a one-channel description is studied, with emphasis on the channel-coupling effects being manifest primarily as an energy dependence (the ''threshold anomaly'') of the real nuclear potential. The relation to the barrier penetration model is examined critically. The results of large-scale coupled-channel calculations are used as ''data'' to illustrate the discussion. Particular emphasis is placed on the importance of reproducing correctly the partial-wave (or ''spin'') distributions. The simple barrier penetration model is found to be adequate to exhibit the strong enhancements due to channel couplings when the threshold anomaly is taken into account, although there may be important corrections due to the long-ranged peripheral absorption, especially from Coulomb excitation. copyright 1987 Academic Press, Inc

ITER, a major step toward nuclear fusion energy; ITER, une etape majeure vers l'energie de fusion

Energy Technology Data Exchange (ETDEWEB)

Ikeda, K.; Holtkamp, N.; Pick, M.; Gauche, F.; Garin, P.; Bigot, B.; Luciani, J.F.; Mougniot, J.C.; Watteau, J.P.; Saoutic, B.; Becoulet, A.; Libeyre, P.; Beaumont, B.; Simonin, A.; Giancarli, L.; Rosenvallon, S.; Gastaldi, O.; Marbach, G.; Boudot, C.; Ioki, K.; Mitchell, N.; Girard, J.Ph.; Giraud, B.; Lignini, F.; Giguet, E.; Bofusch, E.; Friconneau, J.P.; Di Pace, L.; Pampin, R.; Cook, I.; Maisonnier, D.; Campbell, D.; Hayward, J.; Li Puma, A.; Norajitra, P.; Sardain, P.; Tran, M.Q.; Ward, D.; Moslang, A.; Carre, F.; Serpantie, J.P

2007-01-15

This document gathers together a series of articles dedicated to ITER. They are organized into 5 parts. The first part describes the potential of fusion as a source of energy that will be able to face the challenge of a continuously increasing demand. After a reminder of the main fusion reactions and the conditions to obtain fusion, the second part focuses on the magnetic fusion based concepts with a special emphasis on the tokamak configuration. In the third part the main components of ITER are described: first the plasma facing components, then the vacuum vessel, the superconducting magnets and the heating systems. In the fourth part short papers concerning ITER safety, the maintenance through remote handling systems, the tritium breeding blanket, are given, along with a full article on the waste management. It is interesting to notice that the nuclear wastes will represent: -) between 1600 and 3800 tons of housekeeping and process wastes produced during the 20 years of operation of ITER (20% very low level waste, 75% low or medium activity with short life and 5% medium activity with long life), -) about 750 tons from component replacement during ITER active operation, and -) about 30000 tons from the decommissioning of ITER. The last part presents the European concepts for a power plant based on a fusion reactor. A basic design is given along with a state of the art of the research on the materials that will be used for the structures. It is highlighted that synergies between fission and fusion technologies exist in at least 4 areas: nuclear design code system, high temperature materials, safety approach, and in-service inspection, maintenance and dismantling. (A.C.)

17. IAEA fusion energy conference. Extended synopses

International Nuclear Information System (INIS)

1998-01-01

Book of extended synopses of the papers, accepted by a international programme committee for presentation at the 17th IAEA Fusion Energy Conference in Yokohama, Japan. The subjects covered are magnetic confinement experiments, plasma heating and current drive, ITER EDA, inertial fusion energy, innovative concepts, fusion technology and theory

Blue energy - The story of thermonuclear fusion energy

International Nuclear Information System (INIS)

Laval, G.

2007-01-01

The author has written a story of thermonuclear fusion as a future source of energy. This story began about 50 years ago and its last milestone has been the decision of building the ITER machine. This decision has been taken by an international collaboration including a large part of the humanity which shows how great are the expectations put on fusion and that fusion deserves confidence now. For long years fusion energy has been the subject of large controversy due to the questioning about the overcoming of huge theoretical and technological difficulties. Different machines have been built to assess new theoretical developments and to prepare the next step. The physics of hot plasmas has been understood little by little at the pace of the discovery of new instabilities taking place in fusion plasmas. The 2 unique today options: the tokamak-type machine and the laser-driven inertial confinement machine took the lead relatively quickly. (A.C.)

Charged particle accelerators for inertial fusion energy

International Nuclear Information System (INIS)

Humphries, S. Jr.

1991-01-01

The long history of successful commercial applications of charged-particle accelerators is largely a result of initiative by private industry. The Department of Energy views accelerators mainly as support equipment for particle physicists rather than components of an energy generation program. In FY 91, the DOE spent over 850 M$ on building and supporting accelerators for physics research versus 5 M$ on induction accelerators for fusion energy. The author believes this emphasis is skewed. One must address problems of long-term energy sources to preserve the possibility of basic research by future generations. In this paper, the author reviews the rationale for accelerators as inertial fusion drivers, emphasizing that these devices provide a viable path of fusion energy from viewpoints of both physics and engineering. In this paper, he covered the full range of accelerator fusion applications. Because of space limitations, this paper concentrates on induction linacs for ICF, an approach singled out in recent reports by the National Academy of Sciences and the Fusion Policy Advisory Committee as a promising path to long-term fusion power production. Review papers by Cook, Leung, Franzke, Hofmann and Reiser in these proceedings give details on light ion fusion and RF accelerator studies

Chamber technology concepts for inertial fusion energy: Three recent examples

International Nuclear Information System (INIS)

Meier, W.R.; Moir, R.W.; Abdou, M.A.

1997-01-01

The most serious challenges in the design of chambers for inertial fusion energy (IFE) are 1) protecting the first wall from fusion energy pulses on the order of several hundred megajoules released in the form of x rays, target debris, and high energy neutrons, and 2) operating the chamber at a pulse repetition rate of 5-10 Hz (i.e., re-establishing, the wall protection and chamber conditions needed for beam propagation to the target between pulses). In meeting these challenges, designers have capitalized on the ability to separate the fusion burn physics from the geometry and environment of the fusion chamber. Most recent conceptual designs use gases or flowing liquids inside the chamber. Thin liquid layers of molten salt or metal and low pressure, high-Z gases can protect the first wall from x rays and target debris, while thick liquid layers have the added benefit of protecting structures from fusion neutrons thereby significantly reducing the radiation damage and activation. The use of thick liquid walls is predicted to 1) reduce the cost of electricity by avoiding the cost and down time of changing damaged structures, and 2) reduce the cost of development by avoiding the cost of developing a new, low-activation material. Various schemes have been proposed to assure chamber clearing and renewal of the protective features at the required pulse rate. Representative chamber concepts are described, and key technical feasibility issues are identified for each class of chamber. Experimental activities (past, current, and proposed) to address these issues and technology research and development needs are discussed

Effect of breakup on near barrier fusion

International Nuclear Information System (INIS)

Dasgupta, M.; Berriman, A.C.; Butt, R.D.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

2000-01-01

Full text: Unstable neutron-rich nuclei having very weakly bound neutrons exhibit characteristic features such as a neutron halo extending to large radii, and a low energy threshold for breakup. These features may dramatically affect fusion and other reaction processes. It is well accepted that the extended nuclear matter distribution will lead to an enhancement in fusion cross-sections over those for tightly bound nuclei. The effect of couplings to channels which act as doorways to breakup is, however, controversial, with model predictions differing in the relative magnitudes of enhancement and suppression. To investigate the effect on fusion of couplings specific to unstable neutron-rich nuclei, it is necessary to understand (and then predict) the cross-sections expected for their stable counterparts. This requires knowledge of the energy of the average fusion barrier, and information on the couplings. Experimentally all this information can be obtained from precisely measured fusion cross-sections. Such precision measurements of complete fusion cross-sections for 9 Be + 208 Pb and 6 Li, 7 Li + 209 Bi systems have been done at the Australian National University. The distribution of fusion barriers extracted from these data were used to reliably predict the expected fusion cross-sections. Comparison of the theoretical expectations with the experimentally measured cross-sections show conclusively that complete fusion, at above barrier energies, for all three systems is suppressed (by about 30%) compared with the fusion of more tightly bound nuclei. These measurements, in conjunction with incomplete fusion cross-sections, which were also measured, should encourage a complete theoretical description of fusion and breakup

Prospect for inertial fusion energy

International Nuclear Information System (INIS)

Yamanaka, C.

1994-01-01

This paper presents recent inertial fusion experiments at Osaka. The inertial fusion energy reactor used for these experiments was designed according to some principles based on environmental, social and safety considerations. (TEC). 1 fig., 1 ref

A Plan for the Development of Fusion Energy. Final Report to Fusion Energy Sciences Advisory Committee, Fusion Development Path Panel

Energy Technology Data Exchange (ETDEWEB)

None, None

2003-03-05

This report presents a plan for the deployment of a fusion demonstration power plant within 35 years, leading to commercial application of fusion energy by mid-century. The plan is derived from the necessary features of a demonstration fusion power plant and from the time scale defined by President Bush. It identifies critical milestones, key decision points, needed major facilities and required budgets.

17. IAEA fusion energy conference. Extended synopses

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-12-31

Book of extended synopses of the papers, accepted by a international programme committee for presentation at the 17th IAEA Fusion Energy Conference in Yokohama, Japan. The subjects covered are magnetic confinement experiments, plasma heating and current drive, ITER EDA, inertial fusion energy, innovative concepts, fusion technology and theory Refs, figs, tabs

Snowmass 2002: The Fusion Energy Sciences Summer Study

International Nuclear Information System (INIS)

Sauthoff, N.; Navratil, G.; Bangerter, R.

2002-01-01

The Fusion Summer Study 2002 will be a forum for the critical technical assessment of major next-steps in the fusion energy sciences program, and will provide crucial community input to the long-range planning activities undertaken by the DOE [Department of Energy] and the FESAC [Fusion Energy Sciences Advisory Committee]. It will be an ideal place for a broad community of scientists to examine goals and proposed initiatives in burning plasma science in magnetic fusion energy and integrated research experiments in inertial fusion energy. This meeting is open to every member of the fusion energy science community and significant international participation is encouraged. The objectives of the Fusion Summer Study are three: (1) Review scientific issues in burning plasmas to establish the basis for the following two objectives and to address the relations of burning plasma in tokamaks to innovative magnetic fusion energy (MFE) confinement concepts and of ignition in inertial fusion energy (IFE) to integrated research facilities. (2) Provide a forum for critical discussion and review of proposed MFE burning plasma experiments (e.g., IGNITOR, FIRE, and ITER) and assess the scientific and technological research opportunities and prospective benefits of these approaches to the study of burning plasmas. (3) Provide a forum for the IFE community to present plans for prospective integrated research facilities, assess present status of the technical base for each, and establish a timetable and technical progress necessary to proceed for each. Based on significant preparatory work by the fusion community prior to the July Snowmass meeting, the Snowmass working groups will prepare a draft report that documents the scientific and technological benefits of studies of burning plasmas. The report will also include criteria by which the benefits of each approach to fusion science, fusion engineering/technology, and the fusion development path can be assessed. Finally, the report

Z-pinch driven fusion energy

International Nuclear Information System (INIS)

Slutz, Stephen A.; Olson, Craig L.; Rochau, Gary E.; Dezon, Mark S.; Peterson, P.F.; Degroot, J.S.; Jensen, N.; Miller, G.

2000-01-01

The Z machine at Sandia National Laboratories (SNL) is the most powerful multi-module synchronized pulsed-power accelerator in the world. Rapid development of z-pinch loads on Z has led to outstanding progress in the last few years, resulting in radiative powers of up to 280 TW in 4 ns and a total radiated x-ray energy of 1.8 MJ. The present goal is to demonstrate single-shot, high-yield fusion capsules. Pulsed power is a robust and inexpensive technology, which should be well suited for Inertial Fusion Energy, but a rep-rated capability is needed. Recent developments have led to a viable conceptual approach for a rep-rated z-pinch power plant for IFE. This concept exploits the advantages of going to high yield (a few GJ) at low rep-rate (approximately 0.1 Hz), and using a Recyclable Transmission Line (RTL) to provide the necessary standoff between the fusion target and the power plant chamber. In this approach, a portion of the transmission line near the capsule is replaced after each shot. The RTL should be constructed of materials that can easily be separated from the liquid coolant stream and refabricated for a subsequent shots. One possibility is that most of the RTL is formed by casting FLiBe, a salt composed of fluorine, lithium, and beryllium, which is an attractive choice for the reactor coolant, with chemically compatible lead or tin on the surface to provide conductivity. The authors estimate that fusion yields greater than 1 GJ will be required for efficient generation of electricity. Calculations indicate that the first wall will have an acceptable lifetime with these high yields if blast mitigation techniques are used. Furthermore, yields above 5 GJ may allow the use of a compact blanket direct conversion scheme

Low energy RBS-channeling measurement system with the use of a time-of-flight scattered ion detector

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Masataka; Kobayashi, Naoto; Hayashi, Nobuyuki [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)

1996-07-01

We have developed a low energy Rutherford backscattering spectrometry-ion channeling measurement system for the analysis of thin films and solid surfaces with the use of several tens keV hydrogen ions and a time-of-flight particle energy spectrometer. For the detection of the scattered ions new TOF spectrometer has been developed, which consists of two micro-channel-plate detectors. The pulsing of the primary ion beam is not necessary for this type of TOF measurement, and it is possible to observe continues scattered ion beams. The dimension of whole system is very compact compared to the conventional RBS-channeling measurement system with the use of MeV He ions. The energy resolution, {delta} E/E, for 25 keV H{sup +} was 4.1%, which corresponds to the depth resolution of 4.8 nm for silicon. The depth resolution of our system is better than that of conventional RBS system with MeV helium ions and solid state detectors. We have demonstrated the ion channeling measurement by this system with 25 keV hydrogen ions. The system can be available well to the analysis of thin films and solid surfaces with the use of the ion channeling effect. The observation of the reaction between Fe and hydrogen terminated silicon surface was also demonstrated. (J.P.N.)

Overview of US Fusion Energy Programs: January 1993

International Nuclear Information System (INIS)

Crandall, D.H.

1994-01-01

The US Fusion Program is in open-quotes Transition.close quotes This happens so infrequently that no one knows exactly what to expect; it makes everyone a little skittish. Program leadership does make a difference; Secretary Watkins was a positive force for fusion. Energy Research Director Happer remains in his position and is a positive force for scientific quality. Secretary O'Leary has stated that open-quotes Fusion energy holds great promise as an element of the nation's long-term energy supply.close quotes While new leaders may seek new directions with important implications for fusion, it seems reasonable to expect that, for fusion, such changes are likely to emerge slowly. Thus the assumption now is that the fusion priorities remain unchanged. In the spirit of optimism surrounding the new administration, the Fusion Energy Program's intention is to make as much progress as possible on the course presently established

The quest for fusion energy

International Nuclear Information System (INIS)

Johnson, J.L.

1997-10-01

A brief history of the magnetic fusion program from the point of view of a stellarator enthusiast who worked at a major tokamak laboratory. The reason that success in the magnetic fusion energy program is essential is presented. (author)

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

Nuclear fusion - Inexhaustible source of energy for tomorrow

International Nuclear Information System (INIS)

Leiser, M.; Demchenko, V.

1989-09-01

The purpose of this paper is to provide a general description of nuclear fusion as an energy option for the future and to clarify to some extent the various issues - scientific, technological, economic and environmental - which are likely to be relevant to controlled thermonuclear fusion. Section 1 describes the world energy problem and some advantages of nuclear fusion compared to other energy options. Sections 2 and 3 describe the fundamentals of fusion energy, plasma confinement, heating and technological aspects of fusion researches. Some plasma confinement schemes (tokamak, stellarator, inertial confinement fusion) are described. The main experimental results and parameter devices are cited to illustrate the state of the art as of 1989. Various engineering problems associated with reactor design, magnetic systems, materials, plasma purity, fueling, blankets, environment, economics and safety are discussed. A description of both bilateral and multilateral efforts in fusion research under the auspices of the IAEA is presented in Section 4. (author). 11 refs, 4 figs, 1 tab

Fusion energy science: Clean, safe, and abundant energy through innovative science and technology

International Nuclear Information System (INIS)

2001-01-01

Fusion energy science combines the study of the behavior of plasmas--the state of matter that forms 99% of the visible universe--with a vision of using fusion--the energy source of the stars--to create an affordable, plentiful, and environmentally benign energy source for humankind. The dual nature of fusion energy science provides an unfolding panorama of exciting intellectual challenge and a promise of an attractive energy source for generations to come. The goal of this report is a comprehensive understanding of plasma behavior leading to an affordable and attractive fusion energy source

Risk considerations for fusion energy

International Nuclear Information System (INIS)

Kazimi, M.S.

1983-01-01

An assessment is made of the public and occupational health effects implied in the utilization of fusion reactors as a source of electricity. Three conceptual designs for TOKAMAK fusion reactors are used in the assessment. It was assumed in this analysis that a fusion plant will release 10 Ci/day of tritium to the atmosphere. Risk from waste management and accidents are estimated relative to risk of LWR's energy cycle. Comparison of the fusion occupational and public risk from coal, LWR, solar thermal and solar-photovoltaic plants has been undertaken. It is concluded that, compared to other fuel cycles, fusion can potentially have a favorable position with respect to risk

Iterative Fusion of Distributed Decisions over the Gaussian Multiple-Access Channel Using Concatenated BCH-LDGM Codes

Directory of Open Access Journals (Sweden)

Crespo PedroM

2011-01-01

Full Text Available This paper focuses on the data fusion scenario where nodes sense and transmit the data generated by a source to a common destination, which estimates the original information from more accurately than in the case of a single sensor. This work joins the upsurge of research interest in this topic by addressing the setup where the sensed information is transmitted over a Gaussian Multiple-Access Channel (MAC. We use Low Density Generator Matrix (LDGM codes in order to keep the correlation between the transmitted codewords, which leads to an improved received Signal-to-Noise Ratio (SNR thanks to the constructive signal addition at the receiver front-end. At reception, we propose a joint decoder and estimator that exchanges soft information between the LDGM decoders and a data fusion stage. An error-correcting Bose, Ray-Chaudhuri, Hocquenghem (BCH code is further applied suppress the error floor derived from the ambiguity of the MAC channel when dealing with correlated sources. Simulation results are presented for several values of and diverse LDGM and BCH codes, based on which we conclude that the proposed scheme outperforms significantly (by up to 6.3 dB the suboptimum limit assuming separation between Slepian-Wolf source coding and capacity-achieving channel coding.

Perspective on the fusion-fission energy concept

International Nuclear Information System (INIS)

Liikala, R.C.; Perry, R.T.; Teofilo, V.L.

1978-01-01

A concept which has potential for near-term application in the electric power sector of our energy economy is combining fusion and fission technology. The fusion-fission system, called a hybrid, is distinguished from its pure fusion counterpart by incorporation of fertile materials (uranium or thorium) in the blanket region of a fusion machine. The neutrons produced by the fusion process can be used to generate energy through fission events in the blanket or produce fuel for fission reactors through capture events in the fertile material. The performance requirements of the fusion component of hybrids is perceived as being less stringent than those for pure fusion electric power plants. The performance requirements for the fission component of hybrids is perceived as having been demonstrated or could be demonstrated with a modest investment of research and development funds. This paper presents our insights and observations of this concept in the context of why and where it might fit into the picture of meeting our future energy needs. A bibliography of hybrid research is given

Laser for fusion energy

International Nuclear Information System (INIS)

Holzrichter, J.F.

1995-01-01

Solid state lasers have proven to be very versatile tools for the study and demonstration of inertial confinement fusion principles. When lasers were first contemplated to be used for the compression of fusion fuel in the late 1950s, the laser output energy levels were nominally one joule and the power levels were 10 3 watts (pulse duration's of 10 -3 sec). During the last 25 years, lasers optimized for fusion research have been increased in power to typically 100,000 joules with power levels approaching 10 14 watts. As a result of experiments with such lasers at many locations, DT target performance has been shown to be consistent with high gain target output. However, the demonstration of ignition and gain requires laser energies of several megajoules. Laser technology improvements demonstrated over the past decade appear to make possible the construction of such multimegajoule lasers at affordable costs. (author)

Additional gleaning of fusion energy development

International Nuclear Information System (INIS)

Yamamoto, Kenzo; Koizumi, Koichi

2002-09-01

This report summarizes the major topics in the history of fusion energy development in Japan from its dawn to the tokamak fusion experimental reactor, ITER. The domestic circumstances and situation in foreign countries in those days, and the details of each decision and discussion, are described. Since my previous writing, 'Forty years for Nuclear Fusion Energy Development - Big Science in Japan (1997, ERC Press. Co. Ltd.)', was a book which briefly summarize a large quantity of documents on the history, there are many points, which require additional detail explanation. This time, I selected and extracted major topics in the fusion research history, and added additional descriptions and my comments so as to supplement my previous writing. (author)

Strategic plan for the restructured US fusion energy sciences program

International Nuclear Information System (INIS)

1996-08-01

This plan reflects a transition to a restructured fusion program, with a change in focus from an energy technology development program to a fusion energy sciences program. Since the energy crisis of the early 1970's, the U.S. fusion program has presented itself as a goal- oriented fusion energy development program, with milestones that required rapidly increasing budgets. The Energy Policy Act of 1992 also called for a goal-oriented development program consistent with the Department's planning. Actual funding levels, however, have forced a premature narrowing of the program to the tokamak approach. By 1995, with no clear, immediate need driving the schedule for developing fusion energy and with enormous pressure to reduce discretionary spending, Congress cut fusion program funding for FY 1996 by one-third and called for a major restructuring of the program. Based on the recommendations of the Fusion Energy Advisory Committee (FEAC), the Department has decided to pursue a program that concentrates on world-class plasma, science, and on maintaining an involvement in fusion energy science through international collaboration. At the same time, the Japanese and Europeans, with energy situations different from ours, are continuing with their goal- oriented fusion programs. Collaboration with them provides a highly leveraged means of continued involvement in fusion energy science and technology, especially through participation in the engineering and design activities of the International Thermonuclear Experimental Reactor program, ITER. This restructured fusion energy sciences program, with its focus on fundamental fusion science and technology, may well provide insights that lead to more attractive fusion power plants, and will make use of the scientific infrastructure that will allow the United States to launch a fusion energy development program at some future date

Fusion energy 1998. Proceedings. V. 1-4

International Nuclear Information System (INIS)

1999-01-01

The 17-th International Atomic Energy Agency (IAEA) Fusion Energy Conference was held in Yokohama, Japan, 19-24 October 1999. This 6-day conference, which was attended by 835 participants from over 30 countries and two international organizations was organized by the IAEA in co-operation with the Japan Atomic Energy Research Institute (JAERI). More than 360 papers plus 5 summary talks were presented in 23 oral and 8 poster sessions on magnetic confinement and experiments, inertial fusion energy, plasma heating and current drive, ITER engineering design activities, magnetic confinement theory, innovative concepts and fusion technology

Fusion energy 1998. Proceedings. V. 1-4

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-12-01

The 17-th International Atomic Energy Agency (IAEA) Fusion Energy Conference was held in Yokohama, Japan, 19-24 October 1999. This 6-day conference, which was attended by 835 participants from over 30 countries and two international organizations was organized by the IAEA in co-operation with the Japan Atomic Energy Research Institute (JAERI). More than 360 papers plus 5 summary talks were presented in 23 oral and 8 poster sessions on magnetic confinement and experiments, inertial fusion energy, plasma heating and current drive, ITER engineering design activities, magnetic confinement theory, innovative concepts and fusion technology.

Dynamics of complete and incomplete fusion of {sup 6,7}Li, {sup 15}N and {sup 16}O with a {sup 209}Bi target

Energy Technology Data Exchange (ETDEWEB)

Gautam, Manjeet Singh; Vinod, K. [Indus Degree College, Department of Physics, Kinana, Jind, Haryana (India); Khatri, Hitender [Dr. B.R. Ambedekar Institute of Technology, Department of Physics, Port Blair, Andaman and Nicobar (India)

2017-10-15

The dynamics of complete and incomplete fusion of {sup 6,7}Li, {sup 15}N and {sup 16}O with a common target ({sup 209}Bi) around the Coulomb barrier are analyzed within the context of the coupled channel formulation and the energy dependent Woods-Saxon potential (EDWSP) model. The calculated results are compared with experimental fusion cross-sections and it has been shown that complete fusion (CF) data of weakly bound projectile with a heavy target ({sup 209}Bi) gets suppressed at above barrier energies. In the case of the {sup 6}Li + {sup 209}Bi ({sup 7}Li + {sup 209}Bi) reaction, the CF data at above barrier energies is reduced by 34% (26%) with reference to the expectations of the coupled channel approach. However, the theoretical estimations due to the EDWSP model can minimize the suppression factor by 9% with respect to the reported value and consequently the portion of above barrier CF cross-section data of {sup 6}Li + {sup 209}Bi ({sup 7}Li + {sup 209}Bi) reaction is suppressed by 25% (17%) when compared with the present model calculations. This fusion inhibition can be correlated with the low breakup threshold of projectile which in turn breaks up into two fragments in the entrance channel prior to fusion barrier. The total fusion (TF) data, which is sum of complete fusion (CF) data and incomplete fusion (ICF) data, is not suppressed when compared with the predictions of the theoretical approaches and thus breakup channel has very little influence on the total fusion cross-sections. Although the breakup fragments appeared in both reactions, the enhanced suppression effects observed for the lighter projectile can be correlated with its low binding energy associated with the α-breakup channel. Further the outcomes of the EDWSP model reasonably explained the ICF contribution appeared in the fusion of {sup 6,7}Li + {sup 209}Bi reactions. In contrast to this, the observed fusion dynamics of {sup 15}N + {sup 209}Bi and {sup 16}O + {sup 209}Bi reactions, wherein

Spin distribution of evaporation residues formed in complete and incomplete fusion in 16O+154Sm system

Science.gov (United States)

Singh, D.; Linda, Sneha B.; Giri, Pankaj K.; Mahato, Amritraj; Tripathi, R.; Kumar, Harish; Afzal Ansari, M.; Sathik, N. P. M.; Ali, Rahbar; Kumar, Rakesh; Muralithar, S.; Singh, R. P.

2017-11-01

Spin distributions for several evaporation residues populated in the 16O+154Sm system have been measured at projectile energy ≈ 6.2 MeV/A by using the charged particle-γ-coincidence technique. The measured spin distributions of the evaporation residues populated through incomplete fusion associated with 'fast' α and 2α-emission channels are found to be entirely different from fusion-evaporation channels. It is observed that the mean input angular momentum for the evaporation residues formed in incomplete fusion channel is relatively higher than that observed for evaporation residues in complete fusion channels. The feeding intensity profile of evaporation residues populated through complete fusion and incomplete fusion have also been studied. The incomplete fusion channels are found to have narrow range feeding only for high spin states, while complete fusion channels are strongly fed over a broad spin range and widely populated. Comparison of present results with earlier data suggests that the mean input angular momentum values are relatively smaller for spherical target than that of deformed target using the same projectile and incident energy highlighting the role of target deformation in incomplete fusion dynamics.

Investigation of the influence of incomplete fusion on complete fusion of {sup 12}C-induced reactions at {approx} 4-7.2 MeV/nucleon

Energy Technology Data Exchange (ETDEWEB)

Amanuel, F.K. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy); Zelalem, B.; Chaubey, A.K. [Addis Ababa University, Department of Physics, P.O.Box 1176, Addis Ababa (Ethiopia); Agarwal, Avinash [Bareilly College, Department of Physics, Bareilly (India); Rizvi, I.A.; Maheshwari, Anjana; Ahmed, Tauseef [Aligarh Muslim University, Department of Physics, Aligarh (India)

2011-12-15

In this paper, we present the results of our investigation of reaction dynamics leading to incomplete fusion of heavy ions at moderate excitation energies, especially the influence of incomplete fusion on complete fusion of {sup 12}C -induced reactions at specific energies {approx} 4-7.2M eV/nucleon. Excitation functions of various reaction products populated via complete and/or incomplete fusions of a {sup 12}C projectile with {sup 93}Nb, {sup 59}Co and {sup 52}Cr targets were measured at several specific energies {approx} 4-7.2 MeV/nucleon, using a recoil catcher technique, followed by off-line {gamma}-ray spectrometry. The measured excitation functions were compared with theoretical values obtained using the PACE4 statistical model code. For representative non-{alpha}-emitting channels in the {sup 12}C + {sup 93}Nb system, the experimentally measured excitation functions were, in general, found to be in good agreement with the theoretical predictions. However, for {alpha}-emitting channels in the {sup 12}C + {sup 93}Nb, {sup 12}C + {sup 59}Co, and {sup 12}C + {sup 52}Cr systems, the measured excitation functions were higher than the predictions of the theoretical model code, which may be credited to incomplete fusion reactions at these energies. An attempt was made to estimate the incomplete fusion fraction for the present systems, which revealed that the fraction was sensitive to the projectile energy and mass asymmetry of the entrance channel. (orig.)

Low-energy d+d fusion reactions via the Trojan Horse Method

Energy Technology Data Exchange (ETDEWEB)

Tumino, A., E-mail: tumino@lns.infn.it [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Universita degli Studi di Enna ' Kore' , Enna (Italy); Spitaleri, C. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Mukhamedzhanov, A.M. [Cyclotron Institute Texas A and M University, College Station, TX (United States); Typel, S. [Excellence Cluster Universe, Technische Universitaet Muenchen, Garching (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH - Theorie, Darmstadt (Germany); Aliotta, M. [School of Physics and Astronomy, University of Edinburgh, Edinburgh, Scotland (United Kingdom); Scottish Universities Physics Alliance (United Kingdom); Burjan, V. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); Gimenez del Santo, M. [Departamento de Fisica Nuclear, Universitade de Sao Paulo, Sao Paulo (Brazil); Kiss, G.G. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); ATOMKI, Debrecen (Hungary); Kroha, V.; Hons, Z. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); La Cognata, M.; Lamia, L. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Mrazek, J. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); Pizzone, R.G. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Piskor, S. [Nuclear Physics Institute of ASCR, Rez (Czech Republic); Rapisarda, G.G.; Romano, S.; Sergi, M.L.; Sparta, R. [Laboratori Nazionali del Sud, INFN, and Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy)

2011-06-06

The bare nucleus S(E) factors for the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions have been measured for the first time via the Trojan Horse Method off the proton in {sup 3}He from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4{+-}1.8 MeVb for {sup 3}H+p and 60.1{+-}1.9 MeVb for {sup 3}He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

Low-energy d+d fusion reactions via the Trojan Horse Method

International Nuclear Information System (INIS)

Tumino, A.; Spitaleri, C.; Mukhamedzhanov, A.M.; Typel, S.; Aliotta, M.; Burjan, V.; Gimenez del Santo, M.; Kiss, G.G.; Kroha, V.; Hons, Z.; La Cognata, M.; Lamia, L.; Mrazek, J.; Pizzone, R.G.; Piskor, S.; Rapisarda, G.G.; Romano, S.; Sergi, M.L.; Sparta, R.

2011-01-01

The bare nucleus S(E) factors for the 2 H(d,p) 3 H and 2 H(d,n) 3 He reactions have been measured for the first time via the Trojan Horse Method off the proton in 3 He from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre-Main-Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from available direct data with new S(0) values of 57.4±1.8 MeVb for 3 H+p and 60.1±1.9 MeVb for 3 He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

78 FR 15937 - Fusion Energy Sciences Advisory Committee

Science.gov (United States)

2013-03-13

... DEPARTMENT OF ENERGY Fusion Energy Sciences Advisory Committee AGENCY: Department of Energy, Office of Science. ACTION: Notice of open meeting. SUMMARY: This notice announces a meeting of the Fusion Energy Sciences Advisory Committee. The Federal Advisory Committee Act requires that public notice of...

19. IAEA fusion energy conference. Book of abstracts

International Nuclear Information System (INIS)

2002-01-01

Book of abstracts of the papers, accepted by an international programme committee for presentation at the 19th IAEA Fusion Energy Conference in Lyon, France. The subjects covered are magnetic confinement experiments, plasma heating and current drive, ITER EDA, inertial fusion energy, innovative concepts, fusion technology and theory

Net energy gain from DT fusion

International Nuclear Information System (INIS)

Buende, R.

1985-01-01

The net energy which can be gained from an energy raw material by means of a certain conversion system is deduced as the figure-of-merit which adequately characterizes the net energy balance of utilizing an energy source. This potential net energy gain is determined for DT fusion power plants. It is represented as a function of the degree of exploitation of the energy raw material lithium ore and is compared with the net energy which can be gained with LW and FBR power plants by exploiting uranium ore. The comparison clearly demonstrates the net energetic advantage of DT fusion. A sensitivity study shows that this holds even if the energy expenditure for constructing and operating is drastically increased

Theoretical ion implantation profiles for low energy protons under channeling conditions

International Nuclear Information System (INIS)

Nobel, J.A.; Sabin, J.R.; Trickey, S.B.

1994-01-01

The authors present early results from the CHANNEL code, which simulates the passage of ionized projectiles through bulk solids. CHANNEL solves the classical equations of motion for the projectile using a force obtained from the gradient of the quantum mechanically derived coulombic potential of the solid (determined via a full potential augmented plane wave (FLAPW) calculation on the bulk) and a quantum mechanical energy dissipation term, the stopping power, as determined from the method of Echenique, Neiminen, and Ritchie. The code then generates the trajectory of the ionic projectile for a given incident position on the unit cell face and an initial velocity. The authors use CHANNEL to generate an ion (proton) implantation profile for the test case of simple cubic hydrogen with the projectile's initial velocity parallel to the (100) channel. Further preliminary results for ion implantation profiles of protons in diamond structure Si, with initial velocity along the (100) and (110) channels, are given

75 FR 8685 - Fusion Energy Sciences Advisory Committee

Science.gov (United States)

2010-02-25

... DEPARTMENT OF ENERGY Fusion Energy Sciences Advisory Committee AGENCY: Department of Energy, Office of Science. ACTION: Notice of open meeting. SUMMARY: This notice announces a meeting of the Fusion Energy Sciences Advisory Committee. The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770...

76 FR 40714 - Fusion Energy Sciences Advisory Committee

Science.gov (United States)

2011-07-11

... DEPARTMENT OF ENERGY Fusion Energy Sciences Advisory Committee AGENCY: Department of Energy, Office of Science. ACTION: Notice of open meeting. SUMMARY: This notice announces a meeting of the Fusion Energy Sciences Advisory Committee. The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770...

Towards fusion energy as a sustainable energy source: Activities at DTU Physics

DEFF Research Database (Denmark)

Rasmussen, Jesper; Christensen, Alexander Simon; Dam, Magnus

2014-01-01

a fusion plasma) and to confine it within magnetic fields. Learning how such plasmas behave and can be controlled is a crucial step towards realizing fusion as a sustainable energy source.At the Plasma Physics and Fusion Energy (PPFE) section at DTU Physics, we are exploring these issues,focusing on areas...

Reaction mechanisms in heavy ion fusion

Directory of Open Access Journals (Sweden)

Lubian J.

2011-10-01

Full Text Available We discuss the reaction mechanisms involved in heavy ion fusion. We begin with collisions of tightly bound systems, considering three energy regimes: energies above the Coulomb barrier, energies just below the barrier and deep sub-barrier energies. We show that channel coupling effects may influence the fusion process at above-barrier energies, increasing or reducing the cross section predicted by single barrier penetration model. Below the Coulomb barrier, it enhances the cross section, and this effect increases with the system’s size. It is argued that this behavior can be traced back to the increasing importance of Coulomb coupling with the charge of the collision partners. The sharp drop of the fusion cross section observed at deep sub-barrier energies is addressed and the theoretical approaches to this phenomenon are discussed. We then consider the reaction mechanisms involved in fusion reactions of weakly bound systems, paying particular attention to the calculations of complete and incomplete fusion available in the literature.

Robust Frame Synchronization for Low Signal-to-Noise Ratio Channels Using Energy-Corrected Differential Correlation

Directory of Open Access Journals (Sweden)

Kim Pansoo

2009-01-01

Full Text Available Recent standards for wireless transmission require reliable synchronization for channels with low signal-to-noise ratio (SNR as well as with a large amount of frequency offset, which necessitates a robust correlator structure for the initial frame synchronization process. In this paper, a new correlation strategy especially targeted for low SNR regions is proposed and its performance is analyzed. By utilizing a modified energy correction term, the proposed method effectively reduces the variance of the decision variable to enhance the detection performance. Most importantly, the method is demonstrated to outperform all previously reported schemes by a significant margin, for SNRs below 5 dB regardless of the existence of the frequency offsets. A variation of the proposed method is also presented for further enhancement over the channels with small frequency errors. The particular application considered for the performance verification is the second generation digital video broadcasting system for satellites (DVB-S2.

Capacity of Fading Channels in the Low Power Regime

KAUST Repository

Benkhelifa, Fatma

2013-01-01

The low power regime has attracted various researchers in the information theory and communication communities to understand the performance limits of wireless systems. Indeed, the energy consumption is becoming one of the major limiting factors in wireless systems. As such, energy-efficient wireless systems are of major importance to the next generation wireless systems designers. The capacity is a metric that measures the performance limit of a wireless system. The study of the ergodic capacity of some fading channels in the low power regime is the main subject of this thesis. In our study, we consider that the receiver has always a full knowledge of the channel state information. However, we assume that the transmitter has possibly imperfect knowledge of the channel state information, i.e. he knows either perfectly the channel or only an estimated version of the channel. Both radio frequency and free space optical communication channel models are considered. The main contribution of this work is the explicit characterization of how the capacity scales as function of the signal-to-noise ratio in the low power regime. This allows us to characterize the gain due to the perfect knowledge compared to no knowledge of the channel state information at the transmitter. In particular, we show that the gain increases logarithmically for radio frequency communication. However, the gain increases as log2(Pavg) or log4(Pavg) for free-space optical communication, where Pavg is the average power constraint imposed to the input. Furthermore, we characterize the capacity of cascaded fading channels and we applied the result to Rayleigh-product fading channel and to a free-space optical link over gamma-gamma atmospheric turbulence in the presence of pointing errors. Finally, we study the capacity of Nakagami-m fading channel under quality of service constraints, namely the effective capacity. We have shown that the effective capacity converges to Shannon capacity in the very low

Snowmass 2002: The Fusion Energy Sciences Summer Study; TOPICAL

International Nuclear Information System (INIS)

N. Sauthoff; G. Navratil; R. Bangerter

2002-01-01

The Fusion Summer Study 2002 will be a forum for the critical technical assessment of major next-steps in the fusion energy sciences program, and will provide crucial community input to the long-range planning activities undertaken by the DOE[Department of Energy] and the FESAC[Fusion Energy Sciences Advisory Committee]. It will be an ideal place for a broad community of scientists to examine goals and proposed initiatives in burning plasma science in magnetic fusion energy and integrated research experiments in inertial fusion energy. This meeting is open to every member of the fusion energy science community and significant international participation is encouraged. The objectives of the Fusion Summer Study are three: (1) Review scientific issues in burning plasmas to establish the basis for the following two objectives and to address the relations of burning plasma in tokamaks to innovative magnetic fusion energy (MFE) confinement concepts and of ignition in inertial fusion energy (IFE) to integrated research facilities. (2) Provide a forum for critical discussion and review of proposed MFE burning plasma experiments (e.g., IGNITOR, FIRE, and ITER) and assess the scientific and technological research opportunities and prospective benefits of these approaches to the study of burning plasmas. (3) Provide a forum for the IFE community to present plans for prospective integrated research facilities, assess present status of the technical base for each, and establish a timetable and technical progress necessary to proceed for each. Based on significant preparatory work by the fusion community prior to the July Snowmass meeting, the Snowmass working groups will prepare a draft report that documents the scientific and technological benefits of studies of burning plasmas. The report will also include criteria by which the benefits of each approach to fusion science, fusion engineering/technology, and the fusion development path can be assessed. Finally, the report will

Coupled-channel calculation for cross section of fusion and barrier distribution of {}^{16,17,18}O + {}^{16}O reactions

Science.gov (United States)

Fereidonnejad, R.; Sadeghi, H.; Ghambari, M.

2018-03-01

In this work, the effect of multi-phonon excitation on heavy-ion fusion reactions has been studied and fusion barrier distributions of energy intervals near and below the Coulomb barrier have been studied for 16,17,18O + 16O reactions. The structure and deformation of nuclear projectiles have been studied. Given the adaptation of computations to experimental data, our calculations predict the behavior of reactions in intervals of energy in which experimental measurements are not available. In addition the S-factor for these reactions has been calculated. The results showed that the structure and deformation of a nuclear projectile are important factors. The S-factor, obtained in the coupled-channel calculations for the {}^{16}O + {}^{16}O, {}^{17}O +{}^{16}O and {}^{18}O +{}^{16}O reactions, showed good agreement with the experimental data and had a maximum value at an energy near 5, 4.5 and 4 MeV, respectively.

Spin distribution of evaporation residues formed in complete and incomplete fusion in 16O+154Sm system

Directory of Open Access Journals (Sweden)

D. Singh

2017-11-01

Full Text Available Spin distributions for several evaporation residues populated in the 16O+154Sm system have been measured at projectile energy ≈ 6.2 MeV/A by using the charged particle–γ-coincidence technique. The measured spin distributions of the evaporation residues populated through incomplete fusion associated with ‘fast’ α and 2α-emission channels are found to be entirely different from fusion–evaporation channels. It is observed that the mean input angular momentum for the evaporation residues formed in incomplete fusion channel is relatively higher than that observed for evaporation residues in complete fusion channels. The feeding intensity profile of evaporation residues populated through complete fusion and incomplete fusion have also been studied. The incomplete fusion channels are found to have narrow range feeding only for high spin states, while complete fusion channels are strongly fed over a broad spin range and widely populated. Comparison of present results with earlier data suggests that the mean input angular momentum values are relatively smaller for spherical target than that of deformed target using the same projectile and incident energy highlighting the role of target deformation in incomplete fusion dynamics.

Overview of safety and environmental issues for inertial fusion energy

International Nuclear Information System (INIS)

Piet, S.J.; Brereton, S.J.; Tanaka, S.

1996-01-01

This paper summarizes safety and environmental issues of Inertial Fusion Energy (IFE): inventories, effluents, maintenance, accident safety, waste management, and recycling. The fusion confinement approach among inertial and magnetic options affects how the fusion reaction is maintained and which materials surround the reaction chamber. The target fill technology has a major impact on the target factory tritium inventory. IFE fusion reaction chambers usually employ some means to protect the first structural wall from fusion pulses. This protective fluid or granular bed also moderates and absorbs most neutrons before they reach the first structural wall. Although the protective fluid activates, most candidate fluids have low activation hazard. Hands-on maintenance seems practical for the driver, target factory, and secondary coolant systems; remote maintenance is likely required for the reaction chamber, primary coolant, and vacuum exhaust cleanup systems. The driver and fuel target facility are well separated from the main reaction chamber

ITER, a major step toward nuclear fusion energy

International Nuclear Information System (INIS)

Ikeda, K.; Holtkamp, N.; Pick, M.; Gauche, F.; Garin, P.; Bigot, B.; Luciani, J.F.; Mougniot, J.C.; Watteau, J.P.; Saoutic, B.; Becoulet, A.; Libeyre, P.; Beaumont, B.; Simonin, A.; Giancarli, L.; Rosenvallon, S.; Gastaldi, O.; Marbach, G.; Boudot, C.; Ioki, K.; Mitchell, N.; Girard, J.Ph.; Giraud, B.; Lignini, F.; Giguet, E.; Bofusch, E.; Friconneau, J.P.; Di Pace, L.; Pampin, R.; Cook, I.; Maisonnier, D.; Campbell, D.; Hayward, J.; Li Puma, A.; Norajitra, P.; Sardain, P.; Tran, M.Q.; Ward, D.; Moslang, A.; Carre, F.; Serpantie, J.P.

2007-01-01

This document gathers together a series of articles dedicated to ITER. They are organized into 5 parts. The first part describes the potential of fusion as a source of energy that will be able to face the challenge of a continuously increasing demand. After a reminder of the main fusion reactions and the conditions to obtain fusion, the second part focuses on the magnetic fusion based concepts with a special emphasis on the tokamak configuration. In the third part the main components of ITER are described: first the plasma facing components, then the vacuum vessel, the superconducting magnets and the heating systems. In the fourth part short papers concerning ITER safety, the maintenance through remote handling systems, the tritium breeding blanket, are given, along with a full article on the waste management. It is interesting to notice that the nuclear wastes will represent: -) between 1600 and 3800 tons of housekeeping and process wastes produced during the 20 years of operation of ITER (20% very low level waste, 75% low or medium activity with short life and 5% medium activity with long life), -) about 750 tons from component replacement during ITER active operation, and -) about 30000 tons from the decommissioning of ITER. The last part presents the European concepts for a power plant based on a fusion reactor. A basic design is given along with a state of the art of the research on the materials that will be used for the structures. It is highlighted that synergies between fission and fusion technologies exist in at least 4 areas: nuclear design code system, high temperature materials, safety approach, and in-service inspection, maintenance and dismantling. (A.C.)

Starpower: the US and the international quest for fusion energy

International Nuclear Information System (INIS)

1987-10-01

This report, requested by the House Committee on Science, Space, and Technology and endorsed by the Senate Committee on Energy and Natural Resources, reviews the status of magnetic-confinement fusion research and compares its progress with the requirements for development of a useful energy technology. The report does not analyze inertial-confinement fusion research, which is overseen by the House and Senate Armed Services Committees. Contents include: Executive Summary; Introduction and overview; History of fusion research; Fusion science and technology; Fusion as an energy program; Fusion as a research program; Fusion as an international program; Future paths for the magnetic-fusion program; Appendixes--(Non-electric applications for fusion, Other approaches to fusion, Data for figures, List of acronyms and glossary)

Fusion: The Energy of the Universe

International Nuclear Information System (INIS)

Lister, J

2006-01-01

This book outlines the quest for fusion energy. It is presented in a form which is accessible to the interested layman, but which is precise and detailed for the specialist as well. The book contains 12 detailed chapters which cover the whole of the intended subject matter with copious illustrations and a balance between science and the scientific and political context. In addition, the book presents a useful glossary and a brief set of references for further non-specialist reading. Chapters 1 to 3 treat the underlying physics of nuclear energy and of the reactions in the sun and in the stars in considerable detail, including the creation of the matter in the universe. Chapter 4 presents the fusion reactions which can be harnessed on earth, and poses the fundamental problems of realising fusion energy as a source for our use, explaining the background to the Lawson criterion on the required quality of energy confinement, which 50 years later remains our fundamental milestone. Chapter 5 presents the basis for magnetic confinement, introducing some early attempts as well as some straightforward difficulties and treating linear and circular devices. The origins of the stellarator and of the tokamak are described. Chapter 6 is not essential to the mission of usefully harnessing fusion energy, but nonetheless explains to the layman the difference between fusion and fission in weapons, which should help the readers understand the differences as sources of peaceful energy as well, since this popular confusion remains a problem when proposing fusion with the 'nuclear' label. Chapter 7 returns to energy sources with laser fusion, or inertial confinement fusion, which constitutes both military and civil research, depending on the country. The chapter provides a broad overview of the progress right up to today's hopes for fast ignition. The difficulty of harnessing fusion energy by magnetic or inertial confinement has created a breeding ground for what the authors call 'false

Fusion: an energy source for synthetic fuels

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J; Steinberg, M.

1980-01-01

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approx. 50 to 70% are projected for fusion reactors using high temperature blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion

Energy payback and CO2 gas emissions from fusion and solar photovoltaic electric power plants. Final report to Department of Energy, Office of Fusion Energy Sciences

International Nuclear Information System (INIS)

Kulcinski, G.L.

2002-01-01

A cradle-to-grave net energy and greenhouse gas emissions analysis of a modern photovoltaic facility that produces electricity has been performed and compared to a similar analysis on fusion. A summary of the work has been included in a Ph.D. thesis titled ''Life-cycle assessment of electricity generation systems and applications for climate change policy analysis'' by Paul J. Meier, and a synopsis of the work was presented at the 15th Topical meeting on Fusion Energy held in Washington, DC in November 2002. In addition, a technical note on the effect of the introduction of fusion energy on the greenhouse gas emissions in the United States was submitted to the Office of Fusion Energy Sciences (OFES)

Assessment of the Fusion Energy Sciences Program. Final Report

International Nuclear Information System (INIS)

2001-01-01

An assessment of the Office of Fusion Energy Sciences (OFES) program with guidance for future program strategy. The overall objective of this study is to prepare an independent assessment of the scientific quality of the Office of Fusion Energy Sciences program at the Department of Energy. The Fusion Science Assessment Committee (FuSAC) has been appointed to conduct this study

Spatial distribution of ion energy related on electron density in a plasma channel generated in gas clusters by a femtosecond laser

International Nuclear Information System (INIS)

Nam, S. M.; Han, J. M.; Cha, Y. H.; Lee, Y. W.; Rhee, Y. J.; Cha, H. K.

2008-01-01

Neutron generation through Coulomb explosion of deuterium contained gas clusters is known as one of the very effective methods to produce fusion neutrons using a table top terawatt laser. The energy of ions produced through Coulomb explosions is very important factor to generate neutrons efficiently. Until the ion energy reaches around∼MeV level, the D D fusion reaction probability increases exponentially. The understanding of laser beam propagation and laser energy deposition in clusters is very important to improve neutron yields. As the laser beam propagates through clusters medium, laser energy is absorbed in clusters by ionization of molecules consisting clusters. When the backing pressure of gas increases, the average size of clusters increases and which results in higher energy absorption and earlier termination of laser propagation. We first installed a Michelson interferometer to view laser beam traces in a cluster plume and to measure spatial electron density profiles of a plasma channel which was produced by a laser beam. And then we measured the energy of ions distributed along the plasma channel with a translating slit to select ions from narrow parts of a plasma channel. In our experiments, methane gas was used to produce gas clusters at a room temperature and the energy distribution of proton ions for different gas backing pressure were measured by the time of flight method using dual micro channel plates. By comparing the distribution of ion energies and electron densities, we could understand the condition for effective laser energy delivery to clusters

Subbarrier fusion of 16O+112Cd: Cross sections and mean angular momenta

International Nuclear Information System (INIS)

Ackermann, D.; Corradi, L.; Napoli, D.R.; Petrache, C.M.; Spolaore, P.; Stefanini, A.M.; Scarlassara, F.; Beghini, S.; Montagnoli, G.; Segato, G.F.; Signorini, C.

1994-01-01

Fusion cross sections and mean angular momenta have been measured for 16 O+ 112 Cd around the Coulomb barrier. The experimental results are well reproduced by coupled-channels calculations, confirming the validity of this model for mass-asymmetric systems. The predicted asymptotic behaviour of the mean angular momentum at low energies has been observed. ((orig.))

Cluster expression in fission and fusion in high-dimensional macroscopic-microscopic calculations

International Nuclear Information System (INIS)

Iwamoto, Akira; Ichikawa, Takatoshi; Moller, Peter; Sierk, Arnold J.

2004-01-01

We discuss the relation between the fission-fusion potential-energy surfaces of very heavy nuclei and the formation process of these nuclei in cold-fusion reactions. In the potential-energy surfaces, we find a pronounced valley structure, with one valley corresponding to the cold-fusion reaction, the other to fission. As the touching point is approached in the cold-fusion entrance channel, an instability towards dynamical deformation of the projectile occurs, which enhances the fusion cross section. These two 'cluster effects' enhance the production of superheavy nuclei in cold-fusion reactions, in addition to the effect of the low compound-system excitation energy in these reactions. Heavy-ion fusion reactions have been used extensively to synthesize heavy elements beyond actinide nuclei. In order to proceed further in this direction, we need to understand the formation process more precisely, not just the decay process. The dynamics of the formation process are considerably more complex than the dynamics necessary to interpret the spontaneous-fission decay of heavy elements. However, before implementing a full dynamical description it is useful to understand the basic properties of the potential-energy landscape encountered in the initial stages of the collision. The collision process and entrance-channel landscape can conveniently be separated into two parts, namely the early-stage separated system before touching and the late-stage composite system after touching. The transition between these two stages is particularly important, but not very well understood until now. To understand better the transition between the two stages we analyze here in detail the potential energy landscape or 'collision surface' of the system both outside and inside the touching configuration of the target and projectile. In Sec. 2, we discuss calculated five-dimensional potential-energy landscapes inside touching and identify major features. In Sec. 3, we present calculated

Review of the Inertial Fusion Energy Program

Energy Technology Data Exchange (ETDEWEB)

none,

2004-03-29

Igniting fusion fuel in the laboratory remains an alluring goal for two reasons: the desire to study matter under the extreme conditions needed for fusion burn, and the potential of harnessing the energy released as an attractive energy source for mankind. The inertial confinement approach to fusion involves rapidly compressing a tiny spherical capsule of fuel, initially a few millimeters in radius, to densities and temperatures higher than those in the core of the sun. The ignited plasma is confined solely by its own inertia long enough for a significant fraction of the fuel to burn before the plasma expands, cools down and the fusion reactions are quenched. The potential of this confinement approach as an attractive energy source is being studied in the Inertial Fusion Energy (IFE) program, which is the subject of this report. A complex set of interrelated requirements for IFE has motivated the study of novel potential solutions. Three types of “drivers” for fuel compression are presently studied: high-averagepower lasers (HAPL), heavy-ion (HI) accelerators, and Z-Pinches. The three main approaches to IFE are based on these drivers, along with the specific type of target (which contains the fuel capsule) and chamber that appear most promising for a particular driver.

Review of the Inertial Fusion Energy Program

International Nuclear Information System (INIS)

2004-01-01

Igniting fusion fuel in the laboratory remains an alluring goal for two reasons: the desire to study matter under the extreme conditions needed for fusion burn, and the potential of harnessing the energy released as an attractive energy source for mankind. The inertial confinement approach to fusion involves rapidly compressing a tiny spherical capsule of fuel, initially a few millimeters in radius, to densities and temperatures higher than those in the core of the sun. The ignited plasma is confined solely by its own inertia long enough for a significant fraction of the fuel to burn before the plasma expands, cools down and the fusion reactions are quenched. The potential of this confinement approach as an attractive energy source is being studied in the Inertial Fusion Energy (IFE) program, which is the subject of this report. A complex set of interrelated requirements for IFE has motivated the study of novel potential solutions. Three types of @@@drivers@@@ for fuel compression are presently studied: high-averagepower lasers (HAPL), heavy-ion (HI) accelerators, and Z-Pinches. The three main approaches to IFE are based on these drivers, along with the specific type of target (which contains the fuel capsule) and chamber that appear most promising for a particular driver.

Path E alloys: ferritic material development for magnetic fusion energy applications

International Nuclear Information System (INIS)

Holmes, J.J.

1980-09-01

The application of ferritic materials in irradiation environments has received greatly expanded attention in the last few years, both internationally and in the United States. Ferritic materials are found to be resistant to irradiation damage and have in many cases superior properties to those of AISI 316. It has been shown that for magnetic fusion energy applications the low thermal expansion behavior of the ferritic alloy class will result in lower thermal stresses during reactor operation, leading to significantly longer ETF operating lifetimes. The Magnetic Fusion Energy Program therefore now includes a ferritic alloy option for alloy selection and this option has been designated Path E

Fusion energy and Canada's role

International Nuclear Information System (INIS)

Drolet, T.S.

1992-01-01

Fusion is the process of releasing energy from matter which occurs in our sun. Canada is contributing to the development of technology which will permit this process to be harnessed and made available on earth. The international effort has increased from a modest beginning in the 1950s to a level of approximately two billion dollars annually in the 1980s. The purpose of this booklet is to introduce the concept of fusion energy as a technology which should make an important addition to the mix of energy sources for our future. Through a co-ordinated approach, Canada has established several projects which will contribute significantly to the development of technologies in specific areas leading to opportunities now for Canadian industry in the international effort

Public acceptance of fusion energy and scientific feasibility of a fusion reactor. Design of inductively driven long pulse tokamak reactors: IDLT

International Nuclear Information System (INIS)

Ogawa, Yuichi

1998-01-01

Based on scientific data based adopted for designing ITER plasmas and on the advancement of fusion nuclear technology from the recent R and D program, the scientific feasibility of inductively-driven tokamak fusion reactors is studied. A low wall-loading DEMO fusion reactor is designed, which utilizes an austenitic stainless steel in conjunction with significant data bases and operating experiences, since we have given high priority to the early and reliable realization of a tokamak fusion plasma over the cost performance. Since the DEMO reactor with the relatively large volume (i.e., major radius of 10 m) is employed, plasma ignition is achievable with a low fusion power of 0.8 GW, and an operation period of 4 - 5 hours is available only with inductive current drive. Disadvantages of pulsed operation in commercial fusion reactors include fatigue in structural materials and the necessity of an energy storage system to compensate the electric power during the dwell time. To overcome these disadvantages, a pulse length is prolonged up to about 10 hours, resulting in the remarkable reduction of the total cycle number to 10 4 during the life of the fusion plant. (author)

Resonance amplification of the nuclear reaction X(a,b)Y near the a+X channel threshold

International Nuclear Information System (INIS)

Melezhik, V.S.

1991-01-01

Deviation of the cross section for the nuclear reaction X(a,b)Y from the Gamow formula due to an interaction additional to the Coulomb one in the entrance channel has been analyzed. It is shown that the reaction cross section has an oscillating structure at low energies. If the maximum of the first oscillation is close to the threshold of the channel a+X, it has a resonance behaviour. The peculiarity of the cross sections leads to the resonance amplification of the rate for a muon-catalyzed fusion reaction ('in flight' fusion) tμ+d→ 4 He+n+μ at the energy =76 eV and may influence the μ-capture rate in a dense mixture of hydrogen isotopes. 26 refs.; 4 figs

Influence of projectile α-breakup threshold on complete fusion

International Nuclear Information System (INIS)

Mukherjee, A.; Subinit Roy; Pradhan, M.K.; Saha Sarkar, M.; Basu, P.; Dasmahapatra, B.; Bhattacharya, T.; Bhattacharya, S.; Basu, S.K.; Chatterjee, A.; Tripathi, V.; Kailas, S.

2006-01-01

Complete fusion excitation functions for B11,10+Tb159 have been measured at energies around the respective Coulomb barriers, and the existing complete fusion measurements for Li7+Tb159 have been extended to higher energies. The measurements show significant reduction of complete fusion cross sections at above-barrier energies for both the reactions, B10+Tb159 and Li7+Tb159, when compared to those for B11+Tb159. The comparison shows that the extent of suppression of complete fusion cross sections is correlated with the α-separation energies of the projectiles. Also, the two reactions, B10+Tb159 and Li7+Tb159 were found to produce incomplete fusion products at energies near the respective Coulomb barriers, with the α-particle emitting channel being the favoured incomplete fusion process in both the cases

Nuclear fusion, an energy source of the future

International Nuclear Information System (INIS)

Koeppendoerfer, W.

1994-01-01

The paper discusses the possibility to obtain energy by nuclear fusion. It deals successively with: The physical bases of nuclear fusion, research and development with a view to harnessing nuclear fusion, properties of a fusion reactor, and programme and timetable to economic exploitation. (orig./UA) [de

Fusion: The Energy of the Universe

Energy Technology Data Exchange (ETDEWEB)

Lister, J [Ecole Polytechnique Federale de Lausanne (Switzerland)

2006-05-15

This book outlines the quest for fusion energy. It is presented in a form which is accessible to the interested layman, but which is precise and detailed for the specialist as well. The book contains 12 detailed chapters which cover the whole of the intended subject matter with copious illustrations and a balance between science and the scientific and political context. In addition, the book presents a useful glossary and a brief set of references for further non-specialist reading. Chapters 1 to 3 treat the underlying physics of nuclear energy and of the reactions in the sun and in the stars in considerable detail, including the creation of the matter in the universe. Chapter 4 presents the fusion reactions which can be harnessed on earth, and poses the fundamental problems of realising fusion energy as a source for our use, explaining the background to the Lawson criterion on the required quality of energy confinement, which 50 years later remains our fundamental milestone. Chapter 5 presents the basis for magnetic confinement, introducing some early attempts as well as some straightforward difficulties and treating linear and circular devices. The origins of the stellarator and of the tokamak are described. Chapter 6 is not essential to the mission of usefully harnessing fusion energy, but nonetheless explains to the layman the difference between fusion and fission in weapons, which should help the readers understand the differences as sources of peaceful energy as well, since this popular confusion remains a problem when proposing fusion with the 'nuclear' label. Chapter 7 returns to energy sources with laser fusion, or inertial confinement fusion, which constitutes both military and civil research, depending on the country. The chapter provides a broad overview of the progress right up to today's hopes for fast ignition. The difficulty of harnessing fusion energy by magnetic or inertial confinement has created a breeding ground for what the

Energy loss and charge exchange processes of high energy heavy ions channeled in crystals

International Nuclear Information System (INIS)

Poizat, J.C.; Andriamonje, S.; Anne, R.; Faria, N.V.d.C.; Chevallier, M.; Cohen, C.; Dural, J.; Farizon-Mazuy, B.; Gaillard, M.J.; Genre, R.; Hage-Ali, M.; Kirsch, R.; L'hoir, A.; Mory, J.; Moulin, J.; Quere, Y.; Remillieux, J.; Schmaus, D.; Toulemonde, M.

1990-01-01

The interaction of moving ions with single crystals is very sensitive to the orientation of the incident beam with respect to the crystalline directions of the target. Our experiments show that high energy heavy ion channeling deeply modifies their slowing down and charge exchange processes. This is due to the fact that channeled ions interact only with outershell target electrons, which means that the electron density they experience is very low and that the binding energy, and then the momentum distribution of these electrons, are quite different from the corresponding average values associated to random incidence. The two experimental studies presented here show the reduction of the energy loss rate for fast channeled heavy ions and illustrate the two aspects of channeling effects on charge exchange, the reduction of electron loss on one hand, and of electron capture on the other hand

Fusion-product energy loss in inertial confinement fusion plasmas with applications to target burns

International Nuclear Information System (INIS)

Harris, D.B.; Miley, G.H.

1984-01-01

Inertial confinement fusion (ICF) has been proposed as a competitor to magnetic fusion in the drive towards energy production, but ICF target performance still contains many uncertainties. One such area is the energy-loss rate of fusion products. This situation is due in part to the unique plasma parameters encountered in ICF plasmas which are compressed to more than one-thousand times solid density. The work presented here investigates three aspects of this uncertainty

Fusion of 48Ti+58Fe and 58Ni+54Fe below the Coulomb barrier

Science.gov (United States)

Stefanini, A. M.; Montagnoli, G.; Corradi, L.; Courtin, S.; Bourgin, D.; Fioretto, E.; Goasduff, A.; Grebosz, J.; Haas, F.; Mazzocco, M.; Mijatović, T.; Montanari, D.; Pagliaroli, M.; Parascandolo, C.; Scarlassara, F.; Strano, E.; Szilner, S.; Toniolo, N.; Torresi, D.

2015-12-01

Background: No data on the fusion excitation function of 48Ti+58Fe in the energy region near the Coulomb barrier existed prior to the present work, while fusion of 58Ni+54Fe was investigated in detail some years ago, down to very low energies, and clear evidence of fusion hindrance was noticed at relatively high cross sections. 48Ti and 58Fe are soft and have a low-lying quadrupole excitation lying at ≈800 -900 keV only. Instead, 58Ni and 54Fe have a closed shell (protons and neutrons, respectively) and are rather rigid. Purpose: We aim to investigate (1) the possible influence of the different structures of the involved nuclei on the fusion excitation functions far below the barrier and, in particular, (2) whether hindrance is observed in 48Ti+58Fe , and to compare the results with current coupled-channels models. Methods: 48Ti beams from the XTU Tandem accelerator of INFN-Laboratori Nazionali di Legnaro were used. The experimental setup was based on an electrostatic beam separator, and fusion-evaporation residues (ERs) were detected at very forward angles. Angular distributions of ERs were measured. Results: Fusion cross sections of 48Ti+58Fe have been obtained in a range of nearly six orders of magnitude around the Coulomb barrier, down to σ ≃2 μ b . The sub-barrier cross sections of 48Ti+58Fe are much larger than those of 58Ni+54Fe . Significant differences are also observed in the logarithmic derivatives and astrophysical S factors. No evidence of hindrance is observed, because coupled-channels calculations using a standard Woods-Saxon potential are able to reproduce the data in the whole measured energy range. Analogous calculations for 58Ni+54Fe predict clearly too large cross sections at low energies. The two fusion barrier distributions are wide and display a complex structure that is only qualitatively fit by calculations. Conclusions: It is pointed out that all these different trends originate from the dissimilar low-energy nuclear structures of

Log-Gabor Energy Based Multimodal Medical Image Fusion in NSCT Domain

Directory of Open Access Journals (Sweden)

Yong Yang

2014-01-01

Full Text Available Multimodal medical image fusion is a powerful tool in clinical applications such as noninvasive diagnosis, image-guided radiotherapy, and treatment planning. In this paper, a novel nonsubsampled Contourlet transform (NSCT based method for multimodal medical image fusion is presented, which is approximately shift invariant and can effectively suppress the pseudo-Gibbs phenomena. The source medical images are initially transformed by NSCT followed by fusing low- and high-frequency components. The phase congruency that can provide a contrast and brightness-invariant representation is applied to fuse low-frequency coefficients, whereas the Log-Gabor energy that can efficiently determine the frequency coefficients from the clear and detail parts is employed to fuse the high-frequency coefficients. The proposed fusion method has been compared with the discrete wavelet transform (DWT, the fast discrete curvelet transform (FDCT, and the dual tree complex wavelet transform (DTCWT based image fusion methods and other NSCT-based methods. Visually and quantitatively experimental results indicate that the proposed fusion method can obtain more effective and accurate fusion results of multimodal medical images than other algorithms. Further, the applicability of the proposed method has been testified by carrying out a clinical example on a woman affected with recurrent tumor images.

Direct energy conversion system for D-3He fusion

International Nuclear Information System (INIS)

Tomita, Y.; Shu, L.Y.; Momota, H.

1993-11-01

A novel and highly efficient direct energy conversion system is proposed for utilizing D- 3 He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to 'LINAC.' The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DECs bring about the high efficient fusion plant. (author)

Low SNR capacity for MIMO Rician and Rayleigh-product fading channels with single co-channel interferer and noise

KAUST Repository

Zhong, Caijun

2010-09-01

This paper studies the ergodic capacity of multiple-input multiple-output (MIMO) systems with a single co-channel interferer in the low signal-to-noise-ratio (SNR) regime. Two MIMO models namely Rician and Rayleigh-product channels are investigated. Exact analytical expressions for the minimum energy per information bit, {Eb/N0min, and wideband slope, S0, are derived for both channels. Our results show that the minimum energy per information bit is the same for both channels while their wideband slopes differ significantly. Further, the impact of the numbers of transmit and receive antennas, the Rician K factor, the channel mean matrix and the interference-to-noise-ratio (INR) on the capacity, is addressed. Results indicate that interference degrades the capacity by increasing the required minimum energy per information bit and reducing the wideband slope. Simulation results validate our analytical results. © 2010 IEEE.

A rationale for large inertial fusion plants producing hydrogen for powering low emission vehicles

International Nuclear Information System (INIS)

Logan, B.G.

1993-01-01

Inertial Fusion Energy (IFE) has been identified in the 1991 National Energy Strategy, along with Magnetic Fusion Energy (MFE), as one of only three inexhaustible energy sources for long term energy supply (past 2025), the other alternatives being fission and solar energy. Fusion plants, using electrolysis, could also produce hydrogen to power low emission vehicles in a potentially huge future US market: > 500 GWe would be needed for example, to replace all foreign oil imports with equal-energy hydrogen, assuming 70%-efficient electrolysis. Any inexhaustible source of electricity, including IFE and MFE reactors, can thus provide a long term renewable source of hydrogen as well as solar, wind and biomass sources. Hydrogen production by both high temperature thermochemical cycles and by electrolysis has been studied for MFE, but avoiding trace tritium contamination of the hydrogen product would best be assured using electrolysis cells well separated from any fusion coolant loops. The motivations to consider IFE or MFE producing renewable hydrogen are: (1) reducing US dependence on foreign oil imports and the associated trade deficient; (2) a hydrogen-based transportation system could greatly mitigate future air pollution and greenhouse gases; (3) investments in hydrogen pipelines, storage, and distribution systems could be used for a variety of hydrogen sources; (4) a hydrogen pipeline system could access and buffer sufficiently large markets that temporary outages of large (>> 1 GWe size) fusion hydrogen units could be tolerated

Review of the Fusion Theory and Computing Program. Fusion Energy Sciences Advisory Committee (FESAC)

International Nuclear Information System (INIS)

Antonsen, Thomas M.; Berry, Lee A.; Brown, Michael R.; Dahlburg, Jill P.; Davidson, Ronald C.; Greenwald, Martin; Hegna, Chris C.; McCurdy, William; Newman, David E.; Pellegrini, Claudio; Phillips, Cynthia K.; Post, Douglass E.; Rosenbluth, Marshall N.; Sheffield, John; Simonen, Thomas C.; Van Dam, James

2001-01-01

At the November 14-15, 2000, meeting of the Fusion Energy Sciences Advisory Committee, a Panel was set up to address questions about the Theory and Computing program, posed in a charge from the Office of Fusion Energy Sciences (see Appendix A). This area was of theory and computing/simulations had been considered in the FESAC Knoxville meeting of 1999 and in the deliberations of the Integrated Program Planning Activity (IPPA) in 2000. A National Research Council committee provided a detailed review of the scientific quality of the fusion energy sciences program, including theory and computing, in 2000.

Fusion energy

International Nuclear Information System (INIS)

Gross, R.A.

1984-01-01

This textbook covers the physics and technology upon which future fusion power reactors will be based. It reviews the history of fusion, reaction physics, plasma physics, heating, and confinement. Descriptions of commercial plants and design concepts are included. Topics covered include: fusion reactions and fuel resources; reaction rates; ignition, and confinement; basic plasma directory; Tokamak confinement physics; fusion technology; STARFIRE: A commercial Tokamak fusion power plant. MARS: A tandem-mirror fusion power plant; and other fusion reactor concepts

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.)

Fire hazard analysis for fusion energy experiments

International Nuclear Information System (INIS)

Alvares, N.J.; Hasegawa, H.K.

1979-01-01

The 2XIIB mirror fusion facility at Lawrence Livermore Laboratory (LLL) was used to evaluate the fire safety of state-of-the-art fusion energy experiments. The primary objective of this evaluation was to ensure the parallel development of fire safety and fusion energy technology. Through fault-tree analysis, we obtained a detailed engineering description of the 2XIIB fire protection system. This information helped us establish an optimum level of fire protection for experimental fusion energy facilities as well as evaluate the level of protection provided by various systems. Concurrently, we analyzed the fire hazard inherent to the facility using techniques that relate the probability of ignition to the flame spread and heat-release potential of construction materials, electrical and thermal insulations, and dielectric fluids. A comparison of the results of both analyses revealed that the existing fire protection system should be modified to accommodate the range of fire hazards inherent to the 2XIIB facility

Plasma lens focusing and plasma channel transport for heavy ion fusion

International Nuclear Information System (INIS)

Tauschwitz, A.; Yu, S.S.; Bangerter, R.O.

1996-01-01

The final focus lens in an ion beam driven inertial confinement fusion reactor is important since it sets limiting requirements for the quality of the driver beam. Improvements of the focusing capabilities can facilitate the construction of the driver significantly. A focusing system that is of interest both for heavy ion and for light ion drivers is an adiabatic, current carrying plasma lens. This lens is characterized by the fact that it can slowly (adiabatically) reduce the envelope radius of a beam over several betatron oscillations by increasing the focusing magnetic field along a tapered high current discharge. A reduction of the beam diameter by a factor of 3 to 5 seems feasible with this focusing scheme. Such a lens can be used for an ignition test facility where it can be directly coupled to the fusion target. For use in a repetitively working reactor chamber the lens has to be located outside of the reactor and the tightly focused but strongly divergent beam must be confined in a high current transport channel from the end of the lens into the immediate vicinity of the target. Laser preionization of a background gas is an efficient means to direct and stabilize such a channel. Experiments have been started to test both, the principle of adiabatic focusing, and the stability of laser preionized high current discharge channels. (author). 4 figs., 7 refs

Plasma lens focusing and plasma channel transport for heavy ion fusion

Energy Technology Data Exchange (ETDEWEB)

Tauschwitz, A; Yu, S S; Bangerter, R O [Lawrence Berkeley Lab., CA (United States); and others

1997-12-31

The final focus lens in an ion beam driven inertial confinement fusion reactor is important since it sets limiting requirements for the quality of the driver beam. Improvements of the focusing capabilities can facilitate the construction of the driver significantly. A focusing system that is of interest both for heavy ion and for light ion drivers is an adiabatic, current carrying plasma lens. This lens is characterized by the fact that it can slowly (adiabatically) reduce the envelope radius of a beam over several betatron oscillations by increasing the focusing magnetic field along a tapered high current discharge. A reduction of the beam diameter by a factor of 3 to 5 seems feasible with this focusing scheme. Such a lens can be used for an ignition test facility where it can be directly coupled to the fusion target. For use in a repetitively working reactor chamber the lens has to be located outside of the reactor and the tightly focused but strongly divergent beam must be confined in a high current transport channel from the end of the lens into the immediate vicinity of the target. Laser preionization of a background gas is an efficient means to direct and stabilize such a channel. Experiments have been started to test both, the principle of adiabatic focusing, and the stability of laser preionized high current discharge channels. (author). 4 figs., 7 refs.

The prospect of laser fusion energy

International Nuclear Information System (INIS)

Yamanaka, C.

2000-01-01

The inertial confinement fusion research has developed remarkably in these 30 years, which enables us to scope the inertial fusion energy in the next century. The recent progress in the ICF is briefly reviewed. The GEKKO XII n d glass laser has succeeded to get the long cherished world's purpose that was to compress a D-T fuel up to 1000 times the normal density. The neutron yield was some what less than the expected value. The MJ laser system is under construction expecting to ignite and bum a fuel. The alternative way is to use a PW short pulse laser for the fast ignition. The inertial fusion energy strategy is described with economic overviews on IFE power plants. Various applications of IFE are summarized. (author)

Understanding and accepting fusion as an alternative energy source

Energy Technology Data Exchange (ETDEWEB)

Goerz, D.A.

1987-12-10

Fusion, the process that powers our sun, has long promised to be a virtually inexhaustible source of energy for mankind. No other alternative energy source holds such bright promise, and none has ever presentd such formidable scientific and engineering challenges. Serious research efforts have continued for over 30 years in an attempt to harness and control fusion here on earth. Scientists have made considerable progress in the last decade toward achieving the conditions required for fusion power, and recent experimental results and technological progress have made the scientific feasibility of fusion a virtual certainty. With this knowledge and confidence, the emphasis can now shift toward developing power plants that are practical and economical. Although the necessary technology is not in hand today, the extension to an energy producing system in 20 years is just as attainable as was putting a man on the moon. In the next few decades, the world's population will likely double while the demand for energy will nearly quadruple. Realistic projections show that within the next generation a significant fraction of our electric power must come from alternative energy sources. Increasing environmental concerns may further accelerate this timetable in which new energy sources must be introduced. The continued development of fusion systems to help meet the energy needs of the future will require greater public understanding and support of this technology. The fusion community must do more to make the public aware of the fact that energy is a critical international issue and that fusion is a viable and necessary energy technology that will be safe and economical. 12 refs., 8 figs.

Understanding and accepting fusion as an alternative energy source

International Nuclear Information System (INIS)

Goerz, D.A.

1987-01-01

Fusion, the process that powers our sun, has long promised to be a virtually inexhaustible source of energy for mankind. No other alternative energy source holds such bright promise, and none has ever presentd such formidable scientific and engineering challenges. Serious research efforts have continued for over 30 years in an attempt to harness and control fusion here on earth. Scientists have made considerable progress in the last decade toward achieving the conditions required for fusion power, and recent experimental results and technological progress have made the scientific feasibility of fusion a virtual certainty. With this knowledge and confidence, the emphasis can now shift toward developing power plants that are practical and economical. Although the necessary technology is not in hand today, the extension to an energy producing system in 20 years is just as attainable as was putting a man on the moon. In the next few decades, the world's population will likely double while the demand for energy will nearly quadruple. Realistic projections show that within the next generation a significant fraction of our electric power must come from alternative energy sources. Increasing environmental concerns may further accelerate this timetable in which new energy sources must be introduced. The continued development of fusion systems to help meet the energy needs of the future will require greater public understanding and support of this technology. The fusion community must do more to make the public aware of the fact that energy is a critical international issue and that fusion is a viable and necessary energy technology that will be safe and economical. 12 refs., 8 figs

Near and sub-barrier fusion studies with radioactive nuclei: an overview

International Nuclear Information System (INIS)

Majumdar, Harashit

2004-01-01

Full text: Understanding of the reaction mechanism with radioactive nuclei, e.g., halo nuclei, at near barrier energies appears to be a challenging problem at present. Recent experimental and theoretical investigations of fusion of exotic nuclei with stable targets have yielded new insights into the structure of these nuclei and its effects on the fusion reaction dynamics. One interesting and intriguing result of this type of study is the controversy over fusion enhancement in the presence of strong break-up channels. Other novel information include an increase of break-up cross-sections and weakening or absence of threshold anomaly, related to energy dependence of optical model potentials, in the neighbourhood of the barrier. It is believed that the coupling of the entrance channel to different non-elastic channels (including break-up) is responsible for the above phenomena and these aspects are more prominent in the near barrier region. An overview of the experimental studies of fusion excitation function with RIB will be presented

Near and sub-barrier fusion studies with radioactive nuclei: an overview

International Nuclear Information System (INIS)

Majumdar, Harashit

2004-01-01

Full Text: Understanding of the reaction mechanism with radioactive nuclei, e.g., halo nuclei, at near barrier energies appears to be a challenging problem at present. Recent experimental and theoretical investigations of fusion of exotic nuclei with stable targets have yielded new insights into the structure of these nuclei and its effects on the fusion reaction dynamics. One interesting and intriguing result of this type of study is the controversy over fusion enhancement in the presence of strong break-up channels. Other novel information include an increase of break-up cross-sections and weakening or absence of threshold anomaly, related to energy dependence of optical model potentials, in the neighbourhood of the barrier. It is believed that the coupling of the entrance channel to different non-elastic channels (including break-up) is responsible for the above phenomena and these aspects are more prominent in the near barrier region. An overview of the experimental studies of fusion excitation function with RIB will be presented

New approach to information fusion for Lipschitz classifiers ensembles: Application in multi-channel C-OTDR-monitoring systems

Energy Technology Data Exchange (ETDEWEB)

Timofeev, Andrey V.; Egorov, Dmitry V. [LPP “EqualiZoom”, Astana, 010000 (Kazakhstan)

2016-06-08

This paper presents new results concerning selection of an optimal information fusion formula for an ensemble of Lipschitz classifiers. The goal of information fusion is to create an integral classificatory which could provide better generalization ability of the ensemble while achieving a practically acceptable level of effectiveness. The problem of information fusion is very relevant for data processing in multi-channel C-OTDR-monitoring systems. In this case we have to effectively classify targeted events which appear in the vicinity of the monitored object. Solution of this problem is based on usage of an ensemble of Lipschitz classifiers each of which corresponds to a respective channel. We suggest a brand new method for information fusion in case of ensemble of Lipschitz classifiers. This method is called “The Weighing of Inversely as Lipschitz Constants” (WILC). Results of WILC-method practical usage in multichannel C-OTDR monitoring systems are presented.

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.)

Heavy ion reactions at low energies

International Nuclear Information System (INIS)

Nemes, M.C.

1985-01-01

Some general features of the heavy ion reactions at low energies are presented. Some kinds of processes are studied, such as: elastic scattering, peripherical reactions, deep inelastic collisions and fusion. Both, theoretical and experimental perspectives on this field are discussed. (L.C.) [pt

Nuclear fusion as new energy option in a global single-regional energy system model

International Nuclear Information System (INIS)

Eherer, C.; Baumann, M.; Dueweke, J.; Hamacher, T.

2005-01-01

Is there a window of opportunity for fusion on the electricity market under 'business as usual' conditions, and if not, how do the boundary conditions have to look like to open such a window? This question is addressed within a subtask of the Socio-Economic Research on Fusion (SERF) programme of the European Commission. The most advanced energy-modelling framework, the TIMES model generator developed by the Energy Technology System Analysis Project group of the IEA (ETSAP) has been used to implement a global single-regional partial equilibrium energy model. Within the current activities the potential role of fusion power in various future energy scenarios is studied. The final energy demand projections of the baseline of the investigations are based on IIASA-WEC Scenario B. Under the quite conservative baseline assumptions fusion only enters the model solution with 35 GW in 2100 and it can be observed that coal technologies dominate electricity production in 2100. Scenario variations show that the role of fusion power is strongly affected by the availability of GEN IV fission breeding technologies as energy option and by CO 2 emission caps. The former appear to be a major competitor of fusion power while the latter open a window of opportunity for fusion power on the electricity market. An interesting outcome is furthermore that the possible share of fusion electricity is more sensitive to the potential of primary resources like coal, gas and uranium, than to the share of solar and wind power in the system. This indicates that both kinds of technologies, renewables and fusion power, can coexist in future energy systems in case of CO 2 emission policies and/or resource scarcity scenarios. It is shown that Endogenous Technological Learning (ETL), a more consistent description of technological progress than mere time series, has an impact on the model results. (author)

U. S. Fusion Energy Future

International Nuclear Information System (INIS)

Schmidt, John A.; Jassby, Dan; Larson, Scott; Pueyo, Maria; Rutherford, Paul H.

2000-01-01

Fusion implementation scenarios for the US have been developed. The dependence of these scenarios on both the fusion development and implementation paths has been assessed. A range of implementation paths has been studied. The deployment of CANDU fission reactors in Canada and the deployment of fission reactors in France have been assessed as possible models for US fusion deployment. The waste production and resource (including tritium) needs have been assessed. The conclusion that can be drawn from these studies is that it is challenging to make a significant impact on energy production during this century. However, the rapid deployment of fission reactors in Canada and France support fusion implementation scenarios for the US with significant power production during this century. If the country can meet the schedule requirements then the resource needs and waste production are found to be manageable problems

24. IAEA Fusion Energy Conference. Programme and Book of Abstracts

International Nuclear Information System (INIS)

2012-09-01

The International Atomic Energy Agency (IAEA) fosters the exchange of scientific and technical results in nuclear fusion research through its series of Fusion Energy Conferences. The 24th IAEA Fusion Energy Conference (FEC 2012) aims to provide a forum for the discussion of key physics and technology issues as well as innovative concepts of direct relevance to fusion as a source of nuclear energy. With a number of next-step fusion devices currently being implemented - such as the International Thermonuclear Experimental Reactor (ITER) in Cadarache, France, and the National Ignition Facility (NIF) in Livermore, USA - and in view of the concomitant need to demonstrate the technological feasibility of fusion power plants as well as the economical viability of this method of energy production, the fusion community is now facing new challenges. The resolution of these challenges will dictate research orientations in the present and coming decades. The scientific scope of FEC 2012 is, therefore, intended to reflect the priorities of this new era in fusion energy research. The conference aims to be a platform for sharing the results of research and development efforts in both national and international fusion experiments that have been shaped by these new priorities, and thereby help in pinpointing worldwide advances in fusion theory, experiments, technology, engineering, safety and socio-economics. Furthermore, the conference will also set these results against the backdrop of the requirements for a net energy producing fusion device and a fusion power plant in general, and will thus help in defining the way forward. With the participation of international organizations such as the ITER International Organization and EURATOM, as well as the collaboration of more than forty countries and several research institutes, including those working on smaller plasma devices, it is expected that this conference will, as in the past, serve to identify possibilities and means for a

Extricate of incomplete fusion reactions at 4-7 MeV/A System:19F+159Tb

International Nuclear Information System (INIS)

Unnati; Mandal, S.K.; Yadav, A.; Singh, D.P.; Goswami, S.; Singh, B.P.; Sharma, M.K.

2015-01-01

Probing of heavy ion interactions and extricating of incomplete fusion (ICF) reactions at low energy regime is a topic of current interest. The main points of such studies is to explore the effect of various entrance channel parameters, viz., (i) the projectile energy, (ii) the mass asymmetry of interacting partners, and (iii) the input angular momenta imparted into the system. It is also pointed out that a separation of CF (Complete Fusion) from ICF is important for meaningful interpretation towards the splitting of nuclei. Further, considerable efforts are being employed to synthesize super heavy nuclei, the presence of various competing channels may add complexity to the synthesis of super heavy nuclei and obstruct the formation of such nuclei. Although, it is now possible to investigate reaction mechanism involved in formation of such nuclei but experimental studies are limited

Studies on nuclear fusion energy potential based on a long-term world energy and environment model

International Nuclear Information System (INIS)

Tokimatsu, K.; Fujino, J.; Asaoka, Y.

2001-01-01

This study investigates introduction conditions and potential of nuclear fusion energy as energy supply and CO 2 mitigation technologies in the 21st century. Time horizon of the 21st century, 10 regionally allocated world energy/environment model (Linearized Dynamic New Earth 21) is used for this study. Following nuclear fusion technological data are taken into consideration: cost of electricity (COE) in nuclear fusion introduction year, annual COE reduction rates, regional introduction year, and maximum regional plant capacity constraints by maximum plant construction speed. We made simulation under a constraint of atmospheric CO 2 concentration of 550 parts per million by volume (ppmv) targeted at year 2100, assuming that sequestration technologies and unknown innovative technologies for CO 2 reduction are available. The results indicate that under the 550ppm scenario with nuclear fusion within maximum construction speed, 66mill/kWh is required for introducing nuclear fusion in 2050, 92 mill/kWh in 2060, and 106 mill/kWh in 2070. Therefore, tokamak type nuclear fusion reactors of present several reactor cost estimates are expected to be introduced between 2060 and 2070, and electricity generation fraction by nuclear fusion will go around 20% in 2100 if nuclear fusion energy growth is limited only by the maximum construction speed. CO 2 reduction by nuclear fusion introduced in 2050 from business-as-usual (BAU) scenario without nuclear fusion is about 20% of total reduction amount in 2100. In conclusion, nuclear fusion energy is revealed to be one of the candidates of energy supply technologies and CO 2 mitigation technologies. Cost competitiveness and removal of capacity constraint factors are desired for use of nuclear fusion energy in a large scale. (author)

Cold fusion valleys for the synthesis of Z=118 isotopes

International Nuclear Information System (INIS)

Gherghescu, R.

2005-01-01

Cold fusion reactions are investigated with the goal to synthesize Z=118 isotopes with neutron numbers N=162, 168, 172, 176. Potential energy surfaces are calculated as the result of dynamic minimization with independent deformations of the target and projectile, small semi-axis of the projectile and distance between centers as degrees of freedom. An advanced binary macroscopic-microscopic method is used to obtain the deformation energy and the Werner-Wheeler approximation yield the mass tensor. Charge asymmetry is varied for the same mass asymmetry channel which belongs to a given energy valley. The highest penetrability values are obtained for cold fusion channels with Sn, Te and Xe isotopes as projectiles

Fusion for Energy: The European joint undertaking for ITER and the development of fusion energy

International Nuclear Information System (INIS)

Diegele, E.

2009-01-01

Materials development in nuclear fusion for in-vessel components, i.e. for breeder blankets and divertors, has a history of more than two decades. It is the specific in-service and loading conditions and the consequentially required properties in combination with safety standards and social-economic demands that create a unique set of specifications. Objectives of Fusion for Energy (F4E) include: 1) To provide Europe's contribution to the ITER international fusion energy project; 2) To implement the Broader Approach agreement between Euratom and Japan; 3) To prepare for the construction and demonstration of fusion reactors (DEMO). Consequently, activities in F4E focus on structural materials for the first generations of breeder blankets, i.e. ITER Test Blanket Modules (TBM) and DEMO, whereas a Fusion Materials Topical Group implemented under EFDA coordinates R and D on physically based modelling of irradiation effects and R and D in the longer term (new and /or higher risk materials). The paper focuses on martensitic-ferritic steels and (i) reviews briefly the challenges and the rationales for the decisions taken in the past, (ii) analyses the status of the main activities of development and qualification, (iii) indicates unresolved issues, and (iv) outlines future strategies and needs and their implications. Due to the exposure to intense high energy neutron flux, the main issue for breeder materials is high radiation resistance. The First Wall of a breeder blanket should survive 3-5 full power years or, respectively in terms of irradiation damage, typically 50-70 dpa for DEMO and double figures for a power plant. Even though the objective is to have the materials and key fabrication technologies needed for DEMO fully developed and qualified within the next two decades, a major part of the task has to be completed much earlier. Tritium breeding test blanket modules will be installed in ITER with the objective to test DEMO relevant technologies in fusion

Fusion and reactions of exotic nuclei

Directory of Open Access Journals (Sweden)

Sánchez-Benítez A.M.

2011-10-01

Full Text Available Close to the drip lines, the scattering cross sections of halo nuclei show a different behaviour as compared to the tightly bound projectiles of the stability line. Several experiments carried out in the last decade have been dedicated to investigate the competition between transfer, breakup and fusion channels at energies around and below the Coulomb barrier. The rather complex scenario gives rise to conflicting conclusions concerning the effect of breakup and transfer on reaction dynamics and the sub-barrier fusion process. In this work we discuss recent experimental findings in fusion and reactions of 6He halo nucleus at energies around the Coulomb barrier.

Correlation functions with fusion-channel multiplicity in W3 Toda field theory

International Nuclear Information System (INIS)

Belavin, Vladimir; Estienne, Benoit; Foda, Omar; Santachiara, Raoul

2016-01-01

Current studies of W N Toda field theory focus on correlation functions such that the W N highest-weight representations in the fusion channels are multiplicity-free. In this work, we study W 3 Toda 4-point functions with multiplicity in the fusion channel. The conformal blocks of these 4-point functions involve matrix elements of a fully-degenerate primary field with a highest-weight in the adjoint representation of sl 3 , and a fully-degenerate primary field with a highest-weight in the fundamental representation of sl 3 . We show that, when the fusion rules do not involve multiplicities, the matrix elements of the fully-degenerate adjoint field, between two arbitrary descendant states, can be computed explicitly, on equal footing with the matrix elements of the semi-degenerate fundamental field. Using null-state conditions, we obtain a fourth-order Fuchsian differential equation for the conformal blocks. Using Okubo theory, we show that, due to the presence of multiplicities, this differential equation belongs to a class of Fuchsian equations that is different from those that have appeared so far in W N theories. We solve this equation, compute its monodromy group, and construct the monodromy-invariant correlation functions. This computation shows in detail how the ambiguities that are caused by the presence of multiplicities are fixed by requiring monodromy-invariance.

Fusion: A necessary component of US energy policy

International Nuclear Information System (INIS)

Correll, D.L. Jr.

1989-01-01

US energy policy must ensure that its security, its economy, or its world leadership in technology development are not compromised by failure to meet the nation's electrical energy needs. Increased concerns over the greenhouse effect from fossil-fuel combustion mean that US energy policy must consider how electrical energy dependence on oil and coal can be lessened by conservation, renewable energy sources, and advanced energy options (nuclear fission, solar energy, and thermonuclear fusion). In determining how US energy policy is to respond to these issues, it will be necessary to consider what role each of the three advanced energy options might play, and to determine how these options can complement one another. This paper reviews and comments on the principal US studies and legislation that have addressed fusion since 1980, and then suggests a research, development, and demonstration program that is consistent with the conclusions of those prior authorities and that will allow us to determine how fusion technology can fit into a US energy policy that takes a balanced, long term view of US needs. 17 refs

Pathways to Energy from Inertial Fusion. An Integrated Approach. Report of a Coordinated Research Project 2006-2010

International Nuclear Information System (INIS)

2013-04-01

The IAEA has continuously demonstrated its commitment to supporting the development of safe and environmentally clean nuclear fusion energy. Statistics show that at the current rate of energy consumption, fusion energy would remain an inexhaustible energy source for humankind for millions of years. Furthermore, some of the existing and foreseen risks - such as nuclear waste disposal and rising greenhouse gas emissions from the use of fossil fuels - can also be reduced. In the quest for fusion energy, two main lines of research and development are currently being pursued worldwide, namely the inertial and the magnetic confinement fusion concepts. For both approaches, the IAEA has conducted coordinated research activities focusing on specific physics and technological issues relevant the establishment of the knowledge base and foundation for the design and construction of fusion power plants. This report describes the recent research and technological developments and challenges in inertial fusion energy within the framework of such a coordinated research effort. The coordinated research project on Pathways to Energy from Inertial Fusion: An Integrated Approach was initiated in 2006 and concluded in 2010. The project involved experts and institutions from 16 Member States, addressing issues relevant to advancing inertial fusion energy research and development in its practical applications. The key topics addressed include: (i) high repetition rate, low cost, high efficiency ignition drivers; (ii) beam-matter/beam-plasma interaction related to inertial fusion target physics; (iii) target fusion chamber coupling and interface; and (iv) integrated inertial fusion power plant design. Participants in this coordinated research project have contributed 17 detailed research and technology progress reports of work performed at national and international levels. This report compiles all these reports while highlighting the various achievements.

Magnetic fusion energy technology fellowship: Report on survey of institutional coordinators

International Nuclear Information System (INIS)

1993-02-01

In 1980, the Magnetic Fusion Energy Technology (MFET) Fellowship program was established by the US Department of Energy, Office of Fusion Energy, to encourage outstanding students interested in fusion energy technology to continue their education at a qualified graduate school. The basic objective of the MFET Fellowship program is to ensure an adequate supply of scientists in this field by supporting graduate study, training, and research in magnetic fusion energy technology. The program also supports the broader objective of advancing fusion toward the realization of commercially viable energy systems through the research by MFET fellows. The MFET Fellowship program is administered by the Science/Engineering Education Division of Oak Ridge Institute for Science and Education. Guidance for program administration is provided by an academic advisory committee

Influence of the entrance channel in the fusion reaction 318 MeV 74Ge+74Ge

International Nuclear Information System (INIS)

Zhu, L.H.; Cinausero, M.; Angelis, G. de; De Poli, M.; Fioretto, E.; Gadea, A.; Napoli, D.R.; Prete, G.; Lucarelli, F.

1998-01-01

Entrance channel effects in the fusion of heavy ions have been studied by using the 74 Ge+ 74 Ge reaction at 318 MeV. The population of the yrast superdeformed band in 144 Gd shows an increase when compared with the results obtained in the more asymmetric 48 Ti+ 100 Mo reaction at 215 MeV. The relative yields of the different evaporation residues produced in the 74 Ge+ 74 Ge and in the 48 Ti+ 100 Mo reactions are very similar, with the exception of the 145,144 Gd residual nuclei (3n and 4n decay channels) which are populated with a larger yield in the symmetric reaction. Statistical model calculations reproduce qualitatively such effect if a fission delay is explicitly taken into account. Effects related to fusion barrier fluctuations seem to be important in determining the spin distributions of the compound nucleus. The spectra of the high energy γ-rays emitted in the 74 Ge+ 74 Ge reaction have been measured as a function of the γ-ray multiplicity as well as in coincidence with selected evaporation residues. They are reproduced by standard statistical model calculations with GDR parameters taken from systematics, demonstrating that, in agreement with dynamical model prediction, the emission of γ-rays from the dinucleus formed in the earlier stage of the collision is unimportant. (orig.)

20th IAEA fusion energy conference 2004. Conference proceedings

International Nuclear Information System (INIS)

2005-01-01

The 20th International Atomic Energy Agency (IAEA) Fusion Energy Conference (FEC) was held in Vilamoura, Portugal, from 1 to 6 November 2004. The Instituto Superior Tecnico through the Centro de Fusao Nuclear on behalf of the Portuguese Government and the Association EURATOM/IST hosted the conference. The IAEA wishes to express its gratitude to the host. More than 600 delegates representing 33 countries and three international organizations attended the Fusion Energy Conference 2004. The Programme Committee accepted a total of some 437 papers for presentation at the conference. The scientific experimental and theoretical papers have been grouped with respect to the following themes: Overview on magnetic and inertial fusion; Advanced Scenarios and Steady State; Edge Localized Modes; Fusion Technology; Transport Theory; Beta Limits; Hybrid Scenarios; H-mode and Transport; ITER; Alfven Modes and Wave Heating; Operational Limits and Momentum Transport; Energetic Particles and Stability; Neoclassical Tearing Modes; Transport and Turbulence; Inertial Fusion; Configuration Effects and Transport; and Plasma-wall Interaction. The conference adjourned with the announcement of the next IAEA Fusion Energy Conference, which will be held for the first time in the People's Republic of China, in the city of Chengdu, October 16-22, 2006

Proceedings of the Second Fusion-Fission Energy Systems Review Meeting

Energy Technology Data Exchange (ETDEWEB)

None

1977-11-02

The agenda of the meeting was developed to address, in turn, the following major areas: specific problem areas in nuclear energy systems for application of fusion-fission concepts; current and proposed fusion-fission programs in response to the identified problem areas; target costs and projected benefits associated with fusion-fission energy systems; and technical problems associated with the development of fusion-fission concepts. The greatest emphasis was placed on the characteristics of and problems, associated with fuel producing fusion-fission hybrid reactors.

Fusion technologies for Laser Inertial Fusion Energy (LIFE∗

Directory of Open Access Journals (Sweden)

Kramer K.J.

2013-11-01

Full Text Available The Laser Inertial Fusion-based Energy (LIFE engine design builds upon on going progress at the National Ignition Facility (NIF and offers a near-term pathway to commercial fusion. Fusion technologies that are critical to success are reflected in the design of the first wall, blanket and tritium separation subsystems. The present work describes the LIFE engine-related components and technologies. LIFE utilizes a thermally robust indirect-drive target and a chamber fill gas. Coolant selection and a large chamber solid-angle coverage provide ample tritium breeding margin and high blanket gain. Target material selection eliminates the need for aggressive chamber clearing, while enabling recycling. Demonstrated tritium separation and storage technologies limit the site tritium inventory to attractive levels. These key technologies, along with the maintenance and advanced materials qualification program have been integrated into the LIFE delivery plan. This describes the development of components and subsystems, through prototyping and integration into a First Of A Kind power plant.

Formation of a dinuclear complex in collisions between light nuclei and entrance channel limitations to fusion

International Nuclear Information System (INIS)

Shapira, D.; Shivakumar, B.; Ayik, S.; Harmon, B.A.

1986-01-01

A model for fusion of light nuclei has been proposed recently wherein fusion progresses through nucleus-nucleus capture via a dinuclear stage which acts as a doorway to fusion. While this model accounts for the fusion cross sections, it makes no attempt at predicting observables associated with the non-fusion part of the captured flux. A study of products from the decay of the dinuclear complex into non-fusion channels can provide a stringent test for such a model. In this contribution a model which addresses both the binary decay and the fusion of a dinuclear complex formed in the collision is described and model predictions are compared with data. Accompanying contributions discuss the formalism which is used to describe the evolution of the dinuclear complex and present new data which provide information that helps justify the approximations made in applying this model

Fusion energy and nuclear liability considerations

International Nuclear Information System (INIS)

Fork, William E.; Peterson, Charles H.

2014-01-01

For over 60 years, fusion energy has been recognised as a promising technology for safe, secure and environmentally-sustainable commercial electrical power generation. Over the past decade, research and development programmes across the globe have shown progress in developing critical underlying technologies. Approaches ranging from high-temperature plasma magnetic confinement fusion to inertial confinement fusion are increasingly better understood. As scientific research progresses in its aim to achieve fusion 'ignition', where nuclear fusion becomes self-sustaining, the international legal community should consider how fusion power technologies fit within the current nuclear liability legal framework. An understanding of the history of the civil nuclear liability regimes, along with the different risks associated with fusion power, will enable nations to consider the proper legal conditions needed to deploy and commercialise fusion technologies for civil power generation. This note is divided into three substantive parts. It first provides background regarding fusion power and describes the relatively limited risks of fusion technologies when compared with traditional nuclear fission technologies. It then describes the international nuclear liability regime and analyses how fusion power fits within the text of the three leading conventions. Finally, it examines how fusion power may fall within the international nuclear liability framework in the future, a discussion that includes possible amendments to the relevant international liability conventions. It concludes that the unique nature of the current civil nuclear liability regime points towards the development of a more tailored liability solution because of the reduced risks associated with fusion power. (authors)

Unichannel description of the fusion reactions

International Nuclear Information System (INIS)

Franzin, V.L.M.

1987-01-01

Using an effective one channel model which contains channel coupling effects through the presence of an inclusive energy - dependent polarization potential it was studied sub-barrier fusion of the systems A1 Ni+ A2 N1 and 16 O+ A Sm. The consistency of this method is checked by comparing this empirical polarization potential with the one determined from the explicit consideration of a specific channel coupling. (A.C.A.S.) [pt

Double-Pionic Fusion of Nuclear Systems and the ''ABC'' Effect: Approaching a Puzzle by Exclusive and Kinematically Complete Measurements

International Nuclear Information System (INIS)

Bashkanov, M.; Clement, H.; Doroshkevich, E.; Khakimova, O.; Kren, F.; Meier, R.; Pricking, A.; Skorodko, T.; Wagner, G. J.; Bargholtz, C.; Geren, L.; Lindberg, K.; Tegner, P.-E.; Zartova, I.; Berlowski, M.; Stepaniak, J.; Bogoslawsky, D.; Ivanov, G.; Jiganov, E.; Morosov, B.

2009-01-01

The ABC effect--a puzzling low-mass enhancement in the ππ invariant mass spectrum, first observed by Abashian, Booth, and Crowe--is well known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on the first exclusive and kinematically complete measurements of the most basic double-pionic fusion reaction pn→dπ 0 π 0 at beam energies of 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a (ππ) I=L=0 channel phenomenon associated with both a resonancelike energy dependence in the integral cross section and the formation of a ΔΔ system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data

The High Field Path to Practical Fusion Energy

Science.gov (United States)

Mumgaard, Robert; Whyte, D.; Greenwald, M.; Hartwig, Z.; Brunner, D.; Sorbom, B.; Marmar, E.; Minervini, J.; Bonoli, P.; Irby, J.; Labombard, B.; Terry, J.; Vieira, R.; Wukitch, S.

2017-10-01

We propose a faster, lower cost development path for fusion energy enabled by high temperature superconductors, devices at high magnetic field, innovative technologies and modern approaches to technology development. Timeliness, scale, and economic-viability are the drivers for fusion energy to combat climate change and aid economic development. The opportunities provided by high-temperature superconductors, innovative engineering and physics, and new organizational structures identified over the last few years open new possibilities for realizing practical fusion energy that could meet mid-century de-carbonization needs. We discuss re-factoring the fusion energy development path with an emphasis on concrete risk retirement strategies utilizing a modular approach based on the high-field tokamak that leverages the broader tokamak physics understanding of confinement, stability, and operational limits. Elements of this plan include development of high-temperature superconductor magnets, simplified immersion blankets, advanced long-leg divertors, a compact divertor test tokamak, efficient current drive, modular construction, and demountable magnet joints. An R&D plan culminating in the construction of an integrated pilot plant and test facility modeled on the ARC concept is presented.

Ball lightning as a route to fusion energy

International Nuclear Information System (INIS)

Roth, J.R.

1989-01-01

The reality of ball lightning is attested to by observations reported in surveys of large populations, which are the subject of several books. These observations indicate that its characteristics may be relevant to fusion energy applications. Ball lightning can have a diameter up to several meters, a lifetime of over 100 seconds, an energy content in excess of 10 megajoules, and an energy density and a kinetic pressure greater than that of a reacting DT plasma. This paper reviews some of the properties of ball lightning which commend it to the attention of the fusion community, and it discusses some potential advantages and applications of ball lightning fusion reactors. 11 refs., 6 figs., 1 tab

Fusion utilization projections in the United States energy economy

International Nuclear Information System (INIS)

Powell, J.R.; Fillo, J.A.

1979-11-01

The following topics are discussed in some detail in this report: (1) applications of fusion energy, (2) fusion implementation in the US energy system, (3) reactor performance requirements, (4) technology for electric applications, and (5) technology for synthetic fuel/chemical applications

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

The National Ignition Facility. The path to ignition and inertial fusion energy

International Nuclear Information System (INIS)

Eric Storm

2010-01-01

Complete text of publication follows. The National Ignition Facility (NIF), the world's largest and most energetic laser system built for studying inertial confinement fusion (ICF) and high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). NIF's 192 beams are capable of producing 1.8 MJ and 500 TW of ultraviolet light and are configured to create pressures as high as 100 GB, matter temperatures approaching 10 9 and densities over 1000 g/cm 3 . With these capabis70lities, the NIF will enable exploring scientific problems in strategic defense, basic science and fusion energy. One of the early NIF campaigns is focusing on demonstrating laboratory-scale thermonuclear ignition and burn to produce net fusion energy gains of 10-20 with 1.2 to 1.4 MJ of 0.35 μm light. NIF ignition experiments began late in FY2009 as part of the National Ignition Campaign (NIC). Participants of NIC include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory, and the University of Rochester Laboratory for Energetics (LLE) as well as variety of national and international collaborators. The results from these initial experiments show great promise for the relatively near-term achievement of ignition. Capsule implosion experiments at energies up to 1.2 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 low overall backscatter less than 10%. Cryogenic target capability and additional diagnostics are being installed in preparation for layered target deuterium-tritium implosions to be conducted later in 2010. The goal for NIC is to demonstrate a predictable fusion experimental platform by the end of 2012. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of Inertial Fusion Energy (IFE) and

Nuclear Propulsion through Direct Conversion of Fusion Energy: The Fusion Driven Rocket

Science.gov (United States)

Slough, John; Pancotti, Anthony; Kirtley, David; Pihl, Christopher; Pfaff, Michael

2012-01-01

The future of manned space exploration and development of space depends critically on the creation of a dramatically more proficient propulsion architecture for in-space transportation. A very persuasive reason for investigating the applicability of nuclear power in rockets is the vast energy density gain of nuclear fuel when compared to chemical combustion energy. Current nuclear fusion efforts have focused on the generation of electric grid power and are wholly inappropriate for space transportation as the application of a reactor based fusion-electric system creates a colossal mass and heat rejection problem for space application.

High-energy krypton fluoride lasers for inertial fusion.

Science.gov (United States)

Obenschain, Stephen; Lehmberg, Robert; Kehne, David; Hegeler, Frank; Wolford, Matthew; Sethian, John; Weaver, James; Karasik, Max

2015-11-01

Laser fusion researchers have realized since the 1970s that the deep UV light from excimer lasers would be an advantage as a driver for robust high-performance capsule implosions for inertial confinement fusion (ICF). Most of this research has centered on the krypton-fluoride (KrF) laser. In this article we review the advantages of the KrF laser for direct-drive ICF, the history of high-energy KrF laser development, and the present state of the art and describe a development path to the performance needed for laser fusion and its energy application. We include descriptions of the architecture and performance of the multi-kilojoule Nike KrF laser-target facility and the 700 J Electra high-repetition-rate KrF laser that were developed at the U.S. Naval Research Laboratory. Nike and Electra are the most advanced KrF lasers for inertial fusion research and energy applications.

Fusion--fission energy systems, some utility perspectives

International Nuclear Information System (INIS)

Huse, R.A.; Burger, J.M.; Lotker, M.

1974-01-01

Some of the issues that are important in assessing fusion-- fission energy systems from a utility perspective are discussed. A number of qualitative systems-oriented observations are given along with some economic quantification of the benefits from fusion--fission hybrids and their allowed capital cost. (U.S.)

The prospect for fusion energy with light ions

International Nuclear Information System (INIS)

Mehlhorn, T.A.; Adams, R.G.; Bailey, J.E.

1998-01-01

Intense ion beams may be the best option for an Inertial Fusion Energy (IFE) driver. While light ions may be the long-term pulsed power approach to IFE, the current economic climate is such that there is no urgency in developing fusion energy sources. Research on light ion beams at Sandia will be suspended at the end of this fiscal year in favor of z-pinches studying ICF target physics, high yield fusion, and stewardship issues. The authors document the status of light ion research and the understanding of the feasibility of scaling light ions to IFE

Determination of lattice orientation in aluminium alloy grains by low energy gallium ion-channelling

Energy Technology Data Exchange (ETDEWEB)

Silk, Jonathan R. [Aerospace Metal Composites Ltd., RAE Road, Farnborough, GU14 6XE (United Kingdom); Dashwood, Richard J. [WMG, University of Warwick, Coventry, CV4 7AL (United Kingdom); Chater, Richard J., E-mail: r.chater@imperial.ac.u [Department of Materials, Imperial College, London SW7 2AZ (United Kingdom)

2010-06-15

Polished sections of a fine-grained aluminium, silicon carbide metal matrix composite (MMC) alloy were prepared by sputtering using a low energy gallium ion source and column (FIB). The MMC had been processed by high temperature extrusion. Images of the polished surface were recorded using the ion-induced secondary electron emission. The metal matrix grains were distinguished by gallium ion-channelling contrast from the silicon carbide component. The variation of the contrast from the aluminium grains with tilt angle can be recorded and used to determine lattice orientation with the contrast from the silicon carbide (SiC) component as a reference. This method is rapid and suits site-specific investigations where classical methods of sample preparation fail.

Magnetic fusion energy research and development

International Nuclear Information System (INIS)

1984-02-01

This report on the Department of Energy's Magnetic Fusion Program was requested by the Secretary of Energy. The Panel finds that substantial progress has been made in the three years since the previous ERAB review, although budget constraints have precluded the engineering initiatives recommended in that review and authorized in the Magnetic Fusion Energy Engineering Act of 1980 (the Act). Recognizing that the goals of the Act cannot now be met, the Panel recommends that the engineering phase be further postponed in favor of a strong base program in physics and technology, including immediate commitment to a major new tokamak-based device for the investigation of an ignited long-pulse plasma designated in this report as the Burning Core Experiment or BCX. Resources to design such a device could be obtained from within the existing program by redirecting work toward to BCX. At this time it is not possible to assess accurately the potential economic viability of fusion power in the future. The Panel strongly recommends expansion of international collaboration, particularly the joint construction and operation of major new unique facilities, such as the proposed BCX

Z-inertial fusion energy: power plant final report FY 2006.

Energy Technology Data Exchange (ETDEWEB)

Anderson, Mark (University of Wisconsin, Madison, WI); Kulcinski, Gerald (University of Wisconsin, Madison, WI); Zhao, Haihua (University of California, Berkeley, CA); Cipiti, Benjamin B.; Olson, Craig Lee; Sierra, Dannelle P.; Meier, Wayne (Lawrence Livermore National Laboratories); McConnell, Paul E.; Ghiaasiaan, M. (Georgia Institute of Technology, Atlanta, GA); Kern, Brian (Georgia Institute of Technology, Atlanta, GA); Tajima, Yu (University of California, Los Angeles, CA); Campen, Chistopher (University of California, Berkeley, CA); Sketchley, Tomas (University of California, Los Angeles, CA); Moir, R (Lawrence Livermore National Laboratories); Bardet, Philippe M. (University of California, Berkeley, CA); Durbin, Samuel; Morrow, Charles W.; Vigil, Virginia L (University of Wisconsin, Madison, WI); Modesto-Beato, Marcos A.; Franklin, James Kenneth (University of California, Berkeley, CA); Smith, James Dean; Ying, Alice (University of California, Los Angeles, CA); Cook, Jason T.; Schmitz, Lothar (University of California, Los Angeles, CA); Abdel-Khalik, S. (Georgia Institute of Technology, Atlanta, GA); Farnum, Cathy Ottinger; Abdou, Mohamed A. (University of California, Los Angeles, CA); Bonazza, Riccardo (University of Wisconsin, Madison, WI); Rodriguez, Salvador B.; Sridharan, Kumar (University of Wisconsin, Madison, WI); Rochau, Gary Eugene; Gudmundson, Jesse (University of Wisconsin, Madison, WI); Peterson, Per F. (University of California, Berkeley, CA); Marriott, Ed (University of Wisconsin, Madison, WI); Oakley, Jason (University of Wisconsin, Madison, WI)

2006-10-01

This report summarizes the work conducted for the Z-inertial fusion energy (Z-IFE) late start Laboratory Directed Research Project. A major area of focus was on creating a roadmap to a z-pinch driven fusion power plant. The roadmap ties ZIFE into the Global Nuclear Energy Partnership (GNEP) initiative through the use of high energy fusion neutrons to burn the actinides of spent fuel waste. Transmutation presents a near term use for Z-IFE technology and will aid in paving the path to fusion energy. The work this year continued to develop the science and engineering needed to support the Z-IFE roadmap. This included plant system and driver cost estimates, recyclable transmission line studies, flibe characterization, reaction chamber design, and shock mitigation techniques.

Z-inertial fusion energy: power plant final report FY 2006

International Nuclear Information System (INIS)

Anderson, Mark; Kulcinski, Gerald; Zhao, Haihua; Cipiti, Benjamin B.; Olson, Craig Lee; Sierra, Dannelle P.; Meier, Wayne; McConnell, Paul E.; Ghiaasiaan, M.; Kern, Brian; Tajima, Yu; Campen, Chistopher; Sketchley, Tomas; Moir, R; Bardet, Philippe M.; Durbin, Samuel; Morrow, Charles W.; Vigil, Virginia L.; Modesto-Beato, Marcos A.; Franklin, James Kenneth; Smith, James Dean; Ying, Alice; Cook, Jason T.; Schmitz, Lothar; Abdel-Khalik, S.; Farnum, Cathy Ottinger; Abdou, Mohamed A.; Bonazza, Riccardo; Rodriguez, Salvador B.; Sridharan, Kumar; Rochau, Gary Eugene; Gudmundson, Jesse; Peterson, Per F.; Marriott, Ed; Oakley, Jason

2006-01-01

This report summarizes the work conducted for the Z-inertial fusion energy (Z-IFE) late start Laboratory Directed Research Project. A major area of focus was on creating a roadmap to a z-pinch driven fusion power plant. The roadmap ties ZIFE into the Global Nuclear Energy Partnership (GNEP) initiative through the use of high energy fusion neutrons to burn the actinides of spent fuel waste. Transmutation presents a near term use for Z-IFE technology and will aid in paving the path to fusion energy. The work this year continued to develop the science and engineering needed to support the Z-IFE roadmap. This included plant system and driver cost estimates, recyclable transmission line studies, flibe characterization, reaction chamber design, and shock mitigation techniques

Magnetic Fusion Energy Technology Fellowship Program: Summary of program activities for calendar year 1985

International Nuclear Information System (INIS)

1985-01-01

This report summarizes the activities of the US Department of Energy (DOE) Magnetic Fusion Energy Technology Fellowship program (MFETF) for the 1985 calendar year. The MFETF program has continued to support the mission of the Office of Fusion Energy (OFE) and its Division of Development and Technology (DDT) by ensuring the availability of appropriately trained engineering manpower needed to implement the OFE/DDT magnetic fusion energy agenda. This program provides training and research opportunities to highly qualified students at DOE-designated academic, private sector, and government magnetic fusion energy institutions. The objectives of the Magnetic Fusion Energy Technology Fellowship program are: (1) to provide support for graduate study, training, and research in magnetic fusion energy technology; (2) to ensure an adequate supply of appropriately trained manpower to implement the nation's magnetic fusion energy agenda; (3) to raise the visibility of careers in magnetic fusion energy technology and to encourage students to pursue such careers; and (4) to make national magnetic fusion energy facilities available for manpower training

Trans-complex formation by proteolipid channels in the terminal phase of membrane fusion

DEFF Research Database (Denmark)

Peters, C; Bayer, M J; Bühler, S

2001-01-01

-complex formation occurs downstream from trans-SNARE pairing, and depends on both the Rab-GTPase Ypt7 and calmodulin. The maintenance of existing complexes and completion of fusion are independent of trans-SNARE pairs. Reconstituted proteolipids form sealed channels, which can expand to form aqueous pores in a Ca2...

Centralized supercomputer support for magnetic fusion energy research

International Nuclear Information System (INIS)

Fuss, D.; Tull, G.G.

1984-01-01

High-speed computers with large memories are vital to magnetic fusion energy research. Magnetohydrodynamic (MHD), transport, equilibrium, Vlasov, particle, and Fokker-Planck codes that model plasma behavior play an important role in designing experimental hardware and interpreting the resulting data, as well as in advancing plasma theory itself. The size, architecture, and software of supercomputers to run these codes are often the crucial constraints on the benefits such computational modeling can provide. Hence, vector computers such as the CRAY-1 offer a valuable research resource. To meet the computational needs of the fusion program, the National Magnetic Fusion Energy Computer Center (NMFECC) was established in 1974 at the Lawrence Livermore National Laboratory. Supercomputers at the central computing facility are linked to smaller computer centers at each of the major fusion laboratories by a satellite communication network. In addition to providing large-scale computing, the NMFECC environment stimulates collaboration and the sharing of computer codes and data among the many fusion researchers in a cost-effective manner

Fusion Energy for Hydrogen Production

Energy Technology Data Exchange (ETDEWEB)

Fillo, J. A.; Powell, J. R.; Steinberg, M.; Salzano, F.; Benenati, R.; Dang, V.; Fogelson, S.; Isaacs, H.; Kouts, H.; Kushner, M.; Lazareth, O.; Majeski, S.; Makowitz, H.; Sheehan, T. V.

1978-09-01

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approximately 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approximately 50 to 70% are projected for fusion reactors using high temperature blankets.

Low-energy nuclear reactions with double-solenoid- based ...

Indian Academy of Sciences (India)

solenoids to produce low-energy radioactive nuclear beams. In these systems the ... For many years, the disadvantage in these investigations ... fusion or breakup reaction, preferred with large forward-peaked cross-sections. To transfer the ...

Sausage instabilities stabilized by radial motion in Z-discharged plasma channel for beam propagation in LIB-fusion

International Nuclear Information System (INIS)

Murakami, Hiroyuki; Kawata, Shigeo; Niu, Keishiro.

1983-01-01

The stability of current-carrying plasma channels, which have been proposed for transporting intense ion beams from the diodes to the target in LIB-fusion devices, is discussed. The growth rate of the most dangerous surface mode, that is, the axisymmetric sausage instabilities, are examined for plasma channels with or without radial fluid motion. The growth rate of the channel with radial fluid motion is shown to be far smaller than that of the channel with no fluid motion. It is concluded that a stable plasma channel can be formed by radial fluid motion. (author)

Low Energy Nuclear Reactions: 2007 Update

Science.gov (United States)

Krivit, Steven B.

2007-03-01

This paper presents an overview of low energy nuclear reactions, a subset of the field of condensed matter nuclear science. Condensed matter nuclear science studies nuclear effects in and/or on condensed matter, including low energy nuclear reactions, an entirely new branch of science that gained widespread attention and notoriety beginning in 1989 with the announcement of a previously unrecognized source of energy by Martin Fleischmann and Stanley Pons that came to be known as cold fusion. Two branches of LENR are recognized. The first includes a set of reactions like those observed by Fleischmann and Pons that use palladium and deuterium and yield excess heat and helium-4. Numerous mechanisms have been proposed to explain these reactions, however there is no consensus for, or general acceptance of, any of the theories. The claim of fusion is still considered speculative and, as such, is not an ideal term for this work. The other branch is a wide assortment of nuclear reactions that may occur with either hydrogen or deuterium. Anomalous nuclear transmutations are reported that involve light as well as heavy elements. The significant questions that face this field of research are: 1) Are LENRs a genuine nuclear reaction? 2) If so, is there a release of excess energy? 3) If there is, is the energy release cost-effective?

Applying alpha-channeling to mirror machines

Energy Technology Data Exchange (ETDEWEB)

Zhmoginov, A. I.; Fisch, N. J. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544 (United States)

2012-05-15

The {alpha}-channeling effect entails the use of radio-frequency waves to expel and cool high-energetic {alpha} particles born in a fusion reactor; the device reactivity can then be increased even further by redirecting the extracted energy to fuel ions. Originally proposed for tokamaks, this technique has also been shown to benefit open-ended fusion devices. Here, the fundamental theory and practical aspects of {alpha} channeling in mirror machines are reviewed, including the influence of magnetic field inhomogeneity and the effect of a finite wave region on the {alpha}-channeling mechanism. For practical implementation of the {alpha}-channeling effect in mirror geometry, suitable contained weakly damped modes are identified. In addition, the parameter space of candidate waves for implementing the {alpha}-channeling effect can be significantly extended through the introduction of a suitable minority ion species that has the catalytic effect of moderating the transfer of power from the {alpha}-channeling wave to the fuel ions.

Novel Role of Superfluidity in Low-Energy Nuclear Reactions.

Science.gov (United States)

Magierski, Piotr; Sekizawa, Kazuyuki; Wlazłowski, Gabriel

2017-07-28

We demonstrate, within symmetry unrestricted time-dependent density functional theory, the existence of new effects in low-energy nuclear reactions which originate from superfluidity. The dynamics of the pairing field induces solitonic excitations in the colliding nuclear systems, leading to qualitative changes in the reaction dynamics. The solitonic excitation prevents collective energy dissipation and effectively suppresses the fusion cross section. We demonstrate how the variations of the total kinetic energy of the fragments can be traced back to the energy stored in the superfluid junction of colliding nuclei. Both contact time and scattering angle in noncentral collisions are significantly affected. The modification of the fusion cross section and possibilities for its experimental detection are discussed.

Correlation functions with fusion-channel multiplicity in W{sub 3} Toda field theory

Energy Technology Data Exchange (ETDEWEB)

Belavin, Vladimir [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky Avenue 53, 119991 Moscow (Russian Federation); Department of Quantum Physics, Institute for Information Transmission Problems,Bolshoy Karetny per. 19, 127994 Moscow (Russian Federation); Estienne, Benoit [LPTHE, CNRS and Université Pierre et Marie Curie,Sorbonne Universités, 4 Place Jussieu, 75252 Paris Cedex 05 (France); Foda, Omar [School of Mathematics and Statistics, University of Melbourne,Parkville, Victoria 3010 (Australia); Santachiara, Raoul [LPTMS, CNRS (UMR 8626), Université Paris-Saclay,15 rue Georges Clémenceau, 91405 Orsay (France)

2016-06-22

Current studies of W{sub N} Toda field theory focus on correlation functions such that the W{sub N} highest-weight representations in the fusion channels are multiplicity-free. In this work, we study W{sub 3} Toda 4-point functions with multiplicity in the fusion channel. The conformal blocks of these 4-point functions involve matrix elements of a fully-degenerate primary field with a highest-weight in the adjoint representation of sl{sub 3}, and a fully-degenerate primary field with a highest-weight in the fundamental representation of sl{sub 3}. We show that, when the fusion rules do not involve multiplicities, the matrix elements of the fully-degenerate adjoint field, between two arbitrary descendant states, can be computed explicitly, on equal footing with the matrix elements of the semi-degenerate fundamental field. Using null-state conditions, we obtain a fourth-order Fuchsian differential equation for the conformal blocks. Using Okubo theory, we show that, due to the presence of multiplicities, this differential equation belongs to a class of Fuchsian equations that is different from those that have appeared so far in W{sub N} theories. We solve this equation, compute its monodromy group, and construct the monodromy-invariant correlation functions. This computation shows in detail how the ambiguities that are caused by the presence of multiplicities are fixed by requiring monodromy-invariance.

Opportunities in the Fusion Energy Sciences Program. Appendix C: Topical Areas Characterization

Energy Technology Data Exchange (ETDEWEB)

None

1999-06-30

Recent years have brought dramatic advances in the scientific understanding of fusion plasmas and in the generation of fusion power in the laboratory. Today, there is little doubt that fusion energy production is feasible. The challenge is to make fusion energy practical. As a result of the advances of the last few years, there are now exciting opportunities to optimize fusion systems so that an attractive new energy source will be available when it may be needed in the middle of the next century. The risk of conflicts arising from energy shortages and supply cutoffs, as well as the risk of severe environmental impacts from existing methods of energy production, are among the reasons to pursue these opportunities.

Experimental measurement of 12C+16O fusion at stellar energies

Science.gov (United States)

Fang, X.; Tan, W. P.; Beard, M.; deBoer, R. J.; Gilardy, G.; Jung, H.; Liu, Q.; Lyons, S.; Robertson, D.; Setoodehnia, K.; Seymour, C.; Stech, E.; Vande Kolk, B.; Wiescher, M.; deSouza, R. T.; Hudan, S.; Singh, V.; Tang, X. D.; Uberseder, E.

2017-10-01

The total cross section of the 12C+16O fusion reaction has been measured at low energies to investigate the role of this reaction during late stellar evolution burning phases. A high-intensity oxygen beam, produced by the 5 MV pelletron accelerator at the University of Notre Dame, impinged on a thick, ultrapure graphite target. Protons and γ rays were simultaneously measured in the center-of-mass energy range from 3.64 to 5.01 MeV for singles and from 3.73 to 4.84 MeV for coincidence events, using silicon and Ge detectors. Statistical model calculations were employed to interpret the experimental results. The emergence of a new resonance-like broad structure and a decreasing trend in the S -factor data towards lower energies (opposite to previous data) are found for the 12C+16O fusion reaction. Based on these results the uncertainty range of the reaction rate within the temperature range of late stellar burning environments is discussed.

Nuclear phenomena in low-energy nuclear reaction research.

Science.gov (United States)

Krivit, Steven B

2013-09-01

This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

Fusion Energy Division: Annual progress report, period ending December 31, 1987

Energy Technology Data Exchange (ETDEWEB)

Morgan, O.B. Jr.; Berry, L.A.; Sheffield, J.

1988-11-01

The Fusion Program of Oak Ridge National Laboratory (ORNL), a major part of the national fusion program, carries out research in nearly all areas of magnetic fusion. Collaboration among staff from ORNL, Martin Marietta Energy Systems, Inc., private industry, the academic community, and other fusion laboratories, in the United States and abroad, is directed toward the development of fusion as an energy source. This report documents the program's achievements during 1987. Issued as the annual progress report of the ORNL Fusion Energy Division, it also contains information from components of the Fusion Program that are external to the division (about 15% of the program effort). The areas addressed by the Fusion Program include the following: experimental and theoretical research on magnetic confinement concepts, engineering and physics of existing and planned devices, development and testing of diagnostic tools and techniques in support of experiments, assembly and distribution to the fusion community of databases on atomic physics and radiation effects, development and testing of technologies for heating and fueling fusion plasmas, development and testing of superconducting magnets for containing fusion plasmas, and development and testing of materials for fusion devices. Highlights from program activities are included in this report. 126 figs., 15 tabs.

Fusion Energy Division: Annual progress report, period ending December 31, 1987

International Nuclear Information System (INIS)

Morgan, O.B. Jr.; Berry, L.A.; Sheffield, J.

1988-11-01

The Fusion Program of Oak Ridge National Laboratory (ORNL), a major part of the national fusion program, carries out research in nearly all areas of magnetic fusion. Collaboration among staff from ORNL, Martin Marietta Energy Systems, Inc., private industry, the academic community, and other fusion laboratories, in the United States and abroad, is directed toward the development of fusion as an energy source. This report documents the program's achievements during 1987. Issued as the annual progress report of the ORNL Fusion Energy Division, it also contains information from components of the Fusion Program that are external to the division (about 15% of the program effort). The areas addressed by the Fusion Program include the following: experimental and theoretical research on magnetic confinement concepts, engineering and physics of existing and planned devices, development and testing of diagnostic tools and techniques in support of experiments, assembly and distribution to the fusion community of databases on atomic physics and radiation effects, development and testing of technologies for heating and fueling fusion plasmas, development and testing of superconducting magnets for containing fusion plasmas, and development and testing of materials for fusion devices. Highlights from program activities are included in this report. 126 figs., 15 tabs

ITER session at the IAEA fusion energy conference

International Nuclear Information System (INIS)

Stewart, M.J.

2003-01-01

A highlight of this year's Fusion Energy Conference, held in Lyon, France, on 14-19 October, was the participation by the ITER Parties in both a Special ITER Informal Session and in the Fusion Institute Exhibition at the Paella's des Congres de Lyon. These gave conference participants an opportunity to hear the latest on this collaborative international fusion energy research and development project, and to speak with the experts from each of the four sites being offered for the construction of ITER. The Special ITER Informal Session was held on the evening of 16 October and it was very well attended, with approximately 350 conference participants attending

A Bluetooth Low Energy Indoor Positioning System with Channel Diversity, Weighted Trilateration and Kalman Filtering

Science.gov (United States)

Cantón Paterna, Vicente; Paradells Aspas, Josep; Pérez Bullones, María Alejandra

2017-01-01

Indoor Positioning Systems (IPS) using Bluetooth Low Energy (BLE) technology are currently becoming real and available, which has made them grow in popularity and use. However, there are still plenty of challenges related to this technology, especially in terms of Received Signal Strength Indicator (RSSI) fluctuations due to the behaviour of the channels and the multipath effect, that lead to poor precision. In order to mitigate these effects, in this paper we propose and implement a real Indoor Positioning System based on Bluetooth Low Energy, that improves accuracy while reducing power consumption and costs. The three main proposals are: frequency diversity, Kalman filtering and a trilateration method what we have denominated “weighted trilateration”. The analysis of the results proves that all the proposals improve the precision of the system, which goes up to 1.82 m 90% of the time for a device moving in a middle-size room and 0.7 m for static devices. Furthermore, we have proved that the system is scalable and efficient in terms of cost and power consumption. The implemented approach allows using a very simple device (like a SensorTag) on the items to locate. The system enables a very low density of anchor points or references and with a precision better than existing solutions. PMID:29258195

BOOK REVIEW: Fusion: The Energy of the Universe

Science.gov (United States)

Lister, J.

2006-05-01

This book outlines the quest for fusion energy. It is presented in a form which is accessible to the interested layman, but which is precise and detailed for the specialist as well. The book contains 12 detailed chapters which cover the whole of the intended subject matter with copious illustrations and a balance between science and the scientific and political context. In addition, the book presents a useful glossary and a brief set of references for further non-specialist reading. Chapters 1 to 3 treat the underlying physics of nuclear energy and of the reactions in the sun and in the stars in considerable detail, including the creation of the matter in the universe. Chapter 4 presents the fusion reactions which can be harnessed on earth, and poses the fundamental problems of realising fusion energy as a source for our use, explaining the background to the Lawson criterion on the required quality of energy confinement, which 50 years later remains our fundamental milestone. Chapter 5 presents the basis for magnetic confinement, introducing some early attempts as well as some straightforward difficulties and treating linear and circular devices. The origins of the stellarator and of the tokamak are described. Chapter 6 is not essential to the mission of usefully harnessing fusion energy, but nonetheless explains to the layman the difference between fusion and fission in weapons, which should help the readers understand the differences as sources of peaceful energy as well, since this popular confusion remains a problem when proposing fusion with the `nuclear' label. Chapter 7 returns to energy sources with laser fusion, or inertial confinement fusion, which constitutes both military and civil research, depending on the country. The chapter provides a broad overview of the progress right up to today's hopes for fast ignition. The difficulty of harnessing fusion energy by magnetic or inertial confinement has created a breeding ground for what the authors call `false

An Extra Push from Entrance-Channel Effects

International Nuclear Information System (INIS)

Grar, Nabila; Rowley, Neil

2006-01-01

The fusion probability for heavy symmetric systems is known to show certain very specific features. Apart from the large variance of the fusion barrier distribution, it is found that the energy at which the s-wave transmission is 0.5 is shifted to an energy significantly higher than the nominal (e.g. Bass) Coulomb barrier. This last feature is referred to in the literature as the 'extra push' effect. Many models have been devised to explain the origin of these findings. It is worth noting, however, that despite the extra push, the capture cross section is still greatly enhanced at the very lowest energies. This fact cannot be explained within the framework of macroscopic theories involving conditional saddle points or frictional forces. We have performed full coupled-channel calculations for heavy, symmetric systems treating correctly the long-range Coulomb excitations of the collective quadrupole- and octupole-phonon states in the target and projectile. The results obtained show that the extra push and the overall shape of the fusion probability are simply explained by these entrance-channel effects

Systematics of threshold incident energy for deep sub-barrier fusion hindrance

International Nuclear Information System (INIS)

Ichikawa, Takatoshi; Hagino, Kouichi; Iwamoto, Akira

2007-01-01

We systematically evaluate the potential energy at the touching configuration for heavy-ion reactions using various potential models. We point out that the energy at the touching point, especially that estimated with the Krappe-Nix-Sierk (KNS) potential, strongly correlates with the threshold incident energy for steep falloff of fusion cross sections observed recently for several systems at extremely low energies. This clearly indicates that the steep fall-off phenomenon can be attributed to the dynamics after the target and projectile touch with each other, e.g., the tunneling process and the nuclear saturation property in the overlap region

On the path to fusion energy. Teller lecture 2005

International Nuclear Information System (INIS)

Tabak, M.

2007-01-01

There is a need to develop alternate energy sources in the coming century because fossil fuels will become depleted and their use may lead to global climate change. Inertial fusion can become such an energy source, but significant progress must be made before its promise is realized. The high-density approach to inertial fusion suggested by Nuckolls et al. leads reaction chambers compatible with civilian power production. Methods to achieve the good control of hydrodynamic stability and implosion symmetry required to achieve these high fuel densities will be discussed. Fast Ignition, a technique that achieves fusion ignition by igniting fusion fuel after it is assembled, will be described along with its gain curves. Fusion costs of energy for conventional hotspot ignition will be compared with those of Fast Ignition and their capital costs compared with advanced fission plants. Finally, techniques that may improve possible Fast Ignition gains by an order of magnitude and reduce driver scales by an order of magnitude below conventional ignition requirements are described. (author)

Combined diversity and improved energy detection in cooperative spectrum sensing with faded reporting channels

Directory of Open Access Journals (Sweden)

Srinivas Nallagonda

2016-04-01

Full Text Available In this paper we evaluate the performance of cooperative spectrum sensing (CSS where each cognitive radio (CR employs an improved energy detector (IED with multiple antennas and uses selection combining (SC for detecting the primary user (PU in noisy and faded sensing (S channels. We derive an expression for the probability of false alarm and expressions for probability of missed detection in non-faded (AWGN and Rayleigh faded sensing environments in terms of cumulative distribution function (CDF. Each CR transmits its decision about PU via noisy and faded reporting (R channel to fusion center (FC. In this paper we assume that S-channels are noisy and Rayleigh faded while several cases of fading are considered for R-channels such as: (i Hoyt (or Nakagami-q, (ii Rayleigh, (iii Rician (or Nakagami-n, and (iv Weibull. A Binary Symmetric channel (BSC with a fixed error probability (r in the R-channel is also considered. The impact of fading in R-channel, S-channel and several network parameters such as IED parameter, normalized detection threshold, number of CRs, and number of antennas on missed detection and total error probability is assessed. The effects of Hoyt, Rician, and Weibull fading parameters on overall performance of IED-CSS are also highlighted.

Multiple sampling ionization chamber (MUSIC) for investigation of fusion induced by halo nuclei

International Nuclear Information System (INIS)

Petrascu, H.; Kumagai, H.; Tanihata, I.; Fueloep, Zs.; Petrascu, M.

1999-01-01

A high resolution MUSIC for low and medium energy ions up to ∼ 20 AMeV, for investigation of fusion processes induced by halo nuclei, has been achieved. The chamber was used in the first experiments, aiming at investigating fusion processes induced by 9,11 Li with light targets. In these experiments MUSIC was used for the identification of the inclusive evaporation residues produced in the Si detector target, mounted inside the chamber. By using MUSIC it was possible to separate the inclusive spectra corresponding to the fusion processes, from the background due to the energy degraded beam particles. In principle such a chamber could be also used for investigation of particular fusion channels produced in the entrance window. In this case one could obtain the fusion product trajectory angle with the horizontal plane, by coupling each anode pad to a TDC. The chamber was also provided by a position grid, mounted between the Frisch grid and the anode pads. The energy loss distribution widths were measured using α particles. The chamber was filled with P-10 gas at pressures between 200 and 300 torr. The obtained resolution corresponding to a single pad, is close to the limit derived from the theory of Badhwar. (authors)

Effects of reaction channels in subbarrier fusion reactions

International Nuclear Information System (INIS)

Dasso, C.H.

1984-01-01

In this lecture we consider some aspects of fusion reactions between heavy ions at bombarding energies which are below or close to that of the Coulomb barrier. This problem has been traditionally confronted with simple barrier penetration calculations. So we start with a very brief review of what we can call the ''conventional'' procedure. (orig.)

Elastic scattering, fusion, and breakup of light exotic nuclei

Energy Technology Data Exchange (ETDEWEB)

Kolata, J.J. [University of Notre Dame, Physics Department, Notre Dame, IN (United States); Guimaraes, V. [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo, SP (Brazil); Aguilera, E.F. [Instituto Nacional de Investigaciones Nucleares, Departamento de Aceleradores, Mexico, Distrito Federal (Mexico)

2016-05-15

The present status of fusion reactions involving light (A< 20) radioactive projectiles at energies around the Coulomb barrier (E<10 MeV per nucleon) is reviewed, emphasizing measurements made within the last decade. Data on elastic scattering (providing total reaction cross section information) and breakup channels for the involved systems, demonstrating the relationship between these and the fusion channel, are also reviewed. Similarities and differences in the behavior of fusion and total reaction cross section data concerning halo nuclei, weakly-bound but less exotic projectiles, and strongly-bound systems are discussed. One difference in the behavior of fusion excitation functions near the Coulomb barrier seems to emerge between neutron-halo and proton-halo systems. The role of charge has been investigated by comparing the fusion excitation functions, properly scaled, for different neutron- and proton-rich systems. Possible physical explanations for the observed differences are also reviewed. (orig.)

Wave heating and the U.S. magnetic fusion energy program

International Nuclear Information System (INIS)

Staten, H.S.

1985-01-01

The U.S. Government's support of the fusion program is predicated upon the long-term need for the fusion option in our energy future, as well as the near-term benefits associated with developments on the frontier of science and high technology. As a long-term energy option, magnetic fusion energy has the potential to provide an inexpensive, vast, and secure fuel reserve, to be environmentally clean and safe. It has many potential uses, which include production of central station electricity, fuel for fission reactors, synthetic fuels, and process heat for such applications as desalination of sea water. This paper presents an overview of the U.S. Government program for magnetic fusion energy. The goal and objectives of the U.S. program are reviewed followed by a summary of plasma experiments presently under way and the application of wave heating to these experiments

The international magnetic fusion energy program

International Nuclear Information System (INIS)

Fowler, T.K.

1988-01-01

In May of 1988, the long tradition of international cooperation in magnetic fusion energy research culminated in the initiation of design work on the International Thermonuclear Experimental Reactor (ITER). If eventually constructed in the 1990s, ITER would be the world's first magnetic fusion reactor. This paper discusses the background events that led to ITER and the present status of the ITER activity. This paper presents a brief summary of the technical, political, and organizational activities that have led to the creation of the ITER design activity. The ITER activity is now the main focus of international cooperation in magnetic fusion research and one of the largest international cooperative efforts in all of science. 2 refs., 12 figs

Feasibility Studies of Alpha-Channeling in Mirror Machines

International Nuclear Information System (INIS)

Zhmoginov, A.I.; Fisch, N.J.

2010-01-01

The linear magnetic trap is an attractive concept both for fusion reactors and for other plasma applications due to its relative engineering simplicity and high-beta operation. Applying the α-channeling technique to linear traps, such as mirror machines, can benefit this concept by efficiently redirecting α particle energy to fuel ion heating or by otherwise sustaining plasma confinement, thus increasing the effective fusion reactivity. To identify waves suitable for α-channeling a rough optimization of the energy extraction rate with respect to the wave parameters is performed. After the optimal regime is identified, a systematic search for modes with similar parameters in mirror plasmas is performed, assuming quasi-longitudinal or quasi-transverse wave propagation. Several modes suitable for α particle energy extraction are identified for both reactor designs and for proof- of-principle experiments.

Measurement of fusion excitation functions in the system {sup 78}Kr + {sup 100}Mo

Energy Technology Data Exchange (ETDEWEB)

Rehm, K.E.; Jiang, C.L.; Esbensen, H. [and others

1995-08-01

Earlier measurements of fusion reactions involving {sup 78}Kr and {sup 100}Mo projectiles and Ni-targets showed surprisingly large fusion yields at low energies which could not be explained by coupled-channels calculations. The main difference to similar measurements involving the neighboring {sup 86}Kr and {sup 92}Mo isotopes was the different slope of the excitation functions at sub-barrier energies. An analysis of a variety of experiments showed a correlation between the nuclear structure and the slope of the excitation functions, with the {open_quotes}soft{close_quotes} transitional nuclei ({sup 78}Kr, {sup 100}Mo) exhibiting shallower slopes than the {open_quotes}stiff{close_quotes} nuclei ({sup 86}Kr, {sup 92}Mo) measured at the same energies with respect to the barrier. In this experiment we studied the fusion excitation function involving two transitional nuclei {sup 78}Kr + {sup 100}Mo. The measurements were performed with {sup 78}Kr beams from the ECR source at energies between 285-370 MeV. Separation of the evaporation nucleus from the elastically scattered particles was achieved by measuring time-of-flight and magnetic rigidity in the gas-filled spectrograph. The data were completely analyzed. A comparison of the cross sections with measurements for the system {sup 86}Kr + {sup 92}Mo populating the same compound nucleus {sup 178}Pt. It shows good agreement at the highest energies, but quite different falloffs of the excitation functions toward lower energies. Coupled-channels calculations, including multi-phonon excitation for the two systems, are being performed.

Measurement and analysis of excitation functions and observation of mass-asymmetry effect on incomplete fusion dynamics

Directory of Open Access Journals (Sweden)

Rashid M.H.

2011-10-01

Full Text Available Excitation functions for sixteen evaporation residues produced in the interaction of 20Ne with 165Ho have been measured in the projectile energy range ≈88-164 MeV, using catcher foil activation technique followed by gamma-ray spectrometry. It has been found in general that the excitation functions of evaporation residues produced via xn/pxn channels satisfactorily reproduced with the statistical model code PACE-2 after subtraction of precursor decay contribution. The significant enhancement in the measured excitation functions for the residues produced in alpha emission channels over the PACE-2 predictions has been observed. These alpha emission channels are attributed to incomplete fusion reaction process. The results indicate the occurrence of incomplete fusion involving break-up of projectile 20Ne into 4He + 16O and /or 8Be + 12C followed by fusion of one of the fragments with target nucleus 165Ho. The analysis of the present data suggest that probability of incomplete fusion increases with projectile energy. The ICF fraction FICF also increases with increasing mass-asymmetry of the entrance channel.

Bounds on Minimum Energy per Bit for Optical Wireless Relay Channels

Directory of Open Access Journals (Sweden)

A. D. Raza

2014-09-01

Full Text Available An optical wireless relay channel (OWRC is the classical three node network consisting of source, re- lay and destination nodes with optical wireless connectivity. The channel law is assumed Gaussian. This paper studies the bounds on minimum energy per bit required for reliable communication over an OWRC. It is shown that capacity of an OWRC is concave and energy per bit is monotonically increasing in square of the peak optical signal power, and consequently the minimum energy per bit is inversely pro- portional to the square root of asymptotic capacity at low signal to noise ratio. This has been used to develop upper and lower bound on energy per bit as a function of peak signal power, mean to peak power ratio, and variance of channel noise. The upper and lower bounds on minimum energy per bit derived in this paper correspond respectively to the decode and forward lower bound and the min-max cut upper bound on OWRC capacity

Development of Strategic Technology Road map for Establishing Safety Infrastructure of Fusion Energy

International Nuclear Information System (INIS)

Han, B. S.; Cho, S. H.; Kam, S. C.; Kim, K. T.

2009-01-01

The Korean Government established an 'Act for the Promotion of Fusion Energy Development (APFED)' and formulated a 'Strategy Promotion Plan for Fusion Energy Development.' KINS has carried out a safety review of KSTAR (Korea Superconducting Tokamak Advanced Research), for which an application for use was received in 2002 and the license was issued in August 2007. With respect to the APFED, 'Atomic Energy Acts (AEAs)' shall apply in the fusion safety regulation. However the AEAs are not applicable because they aim for dealing with nuclear energy. In this regard, this study was planned to establish safety infrastructure for fusion energy and to develop technologies necessary for verifying the safety. The purpose of this study is to develop a 'Strategic Technology Roadmap (STR) for establishing safety infrastructure of the fusion energy', which displays the content and development schedule and strategy for developing the laws, safety goals and principles, and safety standards applicable for fusion safety regulation, and core technology required for safety regulation of fusion facilities

Role of supercomputers in magnetic fusion and energy research programs

International Nuclear Information System (INIS)

Killeen, J.

1985-06-01

The importance of computer modeling in magnetic fusion (MFE) and energy research (ER) programs is discussed. The need for the most advanced supercomputers is described, and the role of the National Magnetic Fusion Energy Computer Center in meeting these needs is explained

Fusion Energy Sciences Program at LANL

Energy Technology Data Exchange (ETDEWEB)

Leeper, Ramon J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-10-15

This presentation provides a strategic plan and description of investment areas; LANL vision for existing programs; FES portfolio and other specifics related to the Fusion Energy Sciences program at LANL.

78 FR 2259 - Fusion Energy Sciences Advisory Committee

Science.gov (United States)

2013-01-10

... DEPARTMENT OF ENERGY Fusion Energy Sciences Advisory Committee AGENCY: Office of Science... Energy Sciences Advisory Committee. The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770... Energy Sciences; U.S. Department of Energy; 1000 Independence Avenue SW.; Washington, DC 20585-1290...

Approximation of the economy of fusion energy

Czech Academy of Sciences Publication Activity Database

Entler, Slavomír; Horáček, Jan; Dlouhý, T.; Dostál, V.

2018-01-01

Roč. 152, June (2018), s. 489-497 ISSN 0360-5442 Grant - others:AV ČR(CZ) StrategieAV21/2 Program:StrategieAV Institutional support: RVO:61389021 Keywords : Nuclear fusion * Fusion energy * Economy * NPV * LCOE * External costs Subject RIV: JF - Nuclear Energetics OBOR OECD: Thermodynamics Impact factor: 4.520, year: 2016 https://www.sciencedirect.com/science/article/pii/S0360544218305395

Alpha Channeling in a Rotating Plasma

International Nuclear Information System (INIS)

Abraham J. Fetterman; Nathaniel J. Fisch

2008-01-01

The wave-particle α-channeling effect is generalized to include rotating plasma. Specifically, radio frequency waves can resonate with α particles in a mirror machine with E x B rotation to diffuse the α particles along constrained paths in phase space. Of major interest is that the α-particle energy, in addition to amplifying the RF waves, can directly enhance the rotation energy which in turn provides additional plasma confinement in centrifugal fusion reactors. An ancillary benefit is the rapid removal of alpha particles, which increases the fusion reactivity

α Channeling in a Rotating Plasma

International Nuclear Information System (INIS)

Fetterman, Abraham J.; Fisch, Nathaniel J.

2008-01-01

The wave-particle α-channeling effect is generalized to include rotating plasma. Specifically, radio frequency waves can resonate with α particles in a mirror machine with ExB rotation to diffuse the α particles along constrained paths in phase space. Of major interest is that the α-particle energy, in addition to amplifying the rf waves, can directly enhance the rotation energy which in turn provides additional plasma confinement in centrifugal fusion reactors. An ancillary benefit is the rapid removal of alpha particles, which increases the fusion reactivity

Birth to death analysis of the energy payback ratio and CO2 gas emission rates from coal, fission, wind, and DT-fusion electrical power plants

International Nuclear Information System (INIS)

White, Scott W.; Kulcinski, Gerald L.

2000-01-01

The amount of electrical energy produced over the lifetime of coal, LWR fission, UP fusion, and wind power plants is compared to the total amount of energy required to procure the fuel, build, operate, and decommission the power plants. The energy payback ratio varies from a low of 11 for coal plants to a high of 27 for DT-fusion plants. The magnitude of the energy investment and the source of the various energy inputs determine the CO 2 emission factor. This number varies from a low of 9 to a high of 974 tonnes of CO 2 per GW e h for DT-fusion and coal plants, respectively

Enhancements to the Low-Energy Ion Facility at SUNY Geneseo

Science.gov (United States)

Barfield, Zachariah; Kostick, Steven; Nagasing, Ethan; Fletcher, Kurt; Padalino, Stephen

2017-10-01

The Low Energy Ion Facility at SUNY Geneseo is used for detector development and characterization for inertial confinement fusion diagnostics. The system has been upgraded to improve the ion beam quality by reducing contaminant ions. In the new configuration, ions produced by the Peabody Scientific duoplasmatron ion source are accelerated through a potential, focused into a new NEC analyzing magnet and directed to an angle of 30°. A new einzel lens on the output of the magnet chamber focuses the beam into a scattering chamber with a water-cooled target mount and rotatable detector mount plates. The analyzing magnet has been calibrated for deuteron, 4He+, and 4He2+ ion beams at a range of energies, and no significant hysteresis has been observed. The system can accelerate deuterons to energies up to 25 keV to initiate d-d fusion using a deuterated polymer target. Charged particle spectra with protons, tritons, and 3He ions from d-d fusion have been measured at scattering angles ranging from 55° to 135°. A time-of-flight beamline has been designed to measure the energies of ions elastically scattered at 135°. CEM detectors initiate start and stop signals from secondary electrons produced when low energy ions pass through very thin carbon foils. Funded in part by the U.S. Department of Energy through the Laboratory for Laser Energetics.

High-Yield Lithium-Injection Fusion-Energy (HYLIFE) reactor

International Nuclear Information System (INIS)

Blink, J.A.; Hogam, W.J.; Hovingh, J.; Meier, E.R.; Pitts, J.H.

1985-01-01

The High-Yield Lithium-Injection Fusion Energy (HYLIFE) concept to convent inertial confinement fusion energy into electric power has undergone intensive research and refinement at LLNL since 1978. This paper reports on the final HYLIFE design, focusing on five major areas: the HYLIFE reaction chamber (which includes neutronics, liquid-metal jet-array hydrocynamics, and structural design), supporting systems, primary steam system and balance of plant, safety and environmental protection, and costs. An annotated bibliography of reports applicable to HYLIFE is also provided. We conclude that HYLIFE is a particularly viable concept for the safe, clean production of electrical energy. The liquid-metal jet array, HYLIFE's key design feature, protects the surrounding structural components from x-rays, fusion fuel-pellet debris, neutron damage and activation, and high temperatures and stresses, allowing the structure to last for the plant's entire 30-year lifetime without being replaced. 127 refs., 18 figs

Fusion barrier distributions in 28,30Si + 124Sn reactions

International Nuclear Information System (INIS)

Danu, L.S.; Nayak, B.K.; Biswas, D.C.; Saxena, A.; Thomas, R.G.; Mirgule, E.T.; Choudhury, R.K.

2009-01-01

The coupling of various degrees of freedom such as static deformation, inelastic excitation and nucleon transfer with the relative motion gives rise to a distribution of barrier in heavy ion induced fusion reactions. The barrier distribution is a fingerprint of the reaction characterizing the important channel couplings. The relative importance of various couplings in fusion reaction is of topical interest. In an earlier study with deformed projectiles 28,30 Si on 115 In target, it was observed that the barrier distributions get affected due to coulomb reorientation of the deformed projectile nuclei in the field of target nucleus thus giving rise to fusion hindrance at sub-barrier energies. In that study, we considered deformed projectile rotational and positive Q-value transfer channel couplings to relative motion in fusion for investigation of Coulomb reorientation and no inelastic coupling of the 115 In target was considered. In the present work, we have extended the measurements with 124 Sn target and inelastic coupling of target has been considered in the coupled channel calculations. The fusion barrier distributions for 28,30 Si + 124 Sn systems have been obtained by quasi-elastic scattering measurements at backward angles and the results compared with the predictions of coupled channel calculations

Fusion energy research with lasers, direct drive targets, and dry wall chambers

International Nuclear Information System (INIS)

Sethian, J.D.; Obenschain, S.P.; Myers, M.

2003-01-01

We are carrying out a coordinated, focused effort to develop Laser Inertial Fusion Energy. The key components are developed in concert with one another and the science and engineering issues are addressed concurrently. Significant progress has been made in this program: We are evaluating target designs that show it could be possible to achieve the high gains (>100) needed for a practical fusion system. These have a low density CH foam that is wicked with solid DT, and over coated with a thin high-Z layer. Significant advances have been made with the two types of laser are being developed: Krypton Fluoride (KrF) gas lasers and Diode Pumped Solid State Lasers (DPPSL). Both have the potential to meet the fusion energy requirements for rep-rate, efficiency, durability and cost. This paper also presents the advances in development of chamber operating windows (target survival plus no wall erosion), final optics (aluminum at grazing incidence has high reflectivity and exceeds required laser damage threshold), target fabrication (advanced foams and high Z overcoats), and target injection (new facility for target injection and tracking studies). (author)

Fusion Energy Division progress report, 1 January 1990--31 December 1991

International Nuclear Information System (INIS)

Sheffield, J.; Baker, C.C.; Saltmarsh, M.J.

1994-03-01

The Fusion Program of the Oak Ridge National Laboratory (ORNL), a major part of the national fusion program, encompasses nearly all areas of magnetic fusion research. The program is directed toward the development of fusion as an economical and environmentally attractive energy source for the future. The program involves staff from ORNL, Martin Marietta Energy systems, Inc., private industry, the academic community, and other fusion laboratories, in the US and abroad. Achievements resulting from this collaboration are documented in this report, which is issued as the progress report of the ORNL Fusion Energy Division; it also contains information from components for the Fusion Program that are external to the division (about 15% of the program effort). The areas addressed by the Fusion Program include the following: experimental and theoretical research on magnetic confinement concepts; engineering and physics of existing and planned devices, including remote handling; development and testing of diagnostic tools and techniques in support of experiments; assembly and distribution to the fusion community of databases on atomic physics and radiation effects; development and testing of technologies for heating and fueling fusion plasmas; development and testing of superconducting magnets for containing fusion plasmas; development and testing of materials for fusion devices; and exploration of opportunities to apply the unique skills, technology, and techniques developed in the course of this work to other areas (about 15% of the Division's activities). Highlights from program activities during 1990 and 1991 are presented

Fusion Energy Division progress report, 1 January 1990--31 December 1991

Energy Technology Data Exchange (ETDEWEB)

Sheffield, J.; Baker, C.C.; Saltmarsh, M.J.

1994-03-01

The Fusion Program of the Oak Ridge National Laboratory (ORNL), a major part of the national fusion program, encompasses nearly all areas of magnetic fusion research. The program is directed toward the development of fusion as an economical and environmentally attractive energy source for the future. The program involves staff from ORNL, Martin Marietta Energy systems, Inc., private industry, the academic community, and other fusion laboratories, in the US and abroad. Achievements resulting from this collaboration are documented in this report, which is issued as the progress report of the ORNL Fusion Energy Division; it also contains information from components for the Fusion Program that are external to the division (about 15% of the program effort). The areas addressed by the Fusion Program include the following: experimental and theoretical research on magnetic confinement concepts; engineering and physics of existing and planned devices, including remote handling; development and testing of diagnostic tools and techniques in support of experiments; assembly and distribution to the fusion community of databases on atomic physics and radiation effects; development and testing of technologies for heating and fueling fusion plasmas; development and testing of superconducting magnets for containing fusion plasmas; development and testing of materials for fusion devices; and exploration of opportunities to apply the unique skills, technology, and techniques developed in the course of this work to other areas (about 15% of the Division`s activities). Highlights from program activities during 1990 and 1991 are presented.

Decomposition of incomplete fusion

International Nuclear Information System (INIS)

Sobotka, L.B.; Sarantities, D.G.; Stracener, D.W.; Majka, Z.; Abenante, V.; Semkow, T.M.; Hensley, D.C.; Beene, J.R.; Halbert, M.L.

1989-01-01

The velocity distribution of fusion-like products formed in the reaction 701 MeV 28 Si+ 100 Mo is decomposed into 26 incomplete fusion channels. The momentum deficit of the residue per nonevaporative mass unit is approximately equal to the beam momentum per nucleon. The yields of the incomplete fusion channels correlate with the Q-value for projectile fragmentation rather than that for incomplete fusion. The backward angle multiplicities of light particles and heavy ions increase with momentum transfer, however, the heavy ion multiplicities also depend on the extent of the fragmentation of the incomplete fusion channel. These data indicate that at fixed linear momentum transfer, increased fragmentation of the unfused component is related to a reduced transferred angular momentum. 22 refs., 6 figs., 1 tab

Laser fusion and future energy sources - some recent results

International Nuclear Information System (INIS)

Hora, H.

1979-01-01

While the laser fusion is at present producing more genuine fusion neutrons than the tokamak with magnetic confinement, if use of short laser pulses is preferred, the then appearing nonlinear effect causes considerable complications. Nonlinear processes for the preferred geometry of perpendicular incidence can avoid the problems of resonance absorption, while parametric instabilities have no quantitative influence on the energy balance. The early stages of interaction show the generation of thick 'cold' compressing plasma blocks which can be used for a nonlinear force fast pusher compression of high efficiency (low entropy production). A short time interaction results in a fast thermalization of the plasma corona by soliton decay and this provides the necessary condition for Nuckolls' gasdynamic ablation compression. For longer duration of high intensity irradiation, a pulsation of reflectivity and thermalization will complicate the interaction

The National Ignition Facility (NIF): A path to fusion energy

International Nuclear Information System (INIS)

Moses, Edward I.

2008-01-01

Fusion energy has long been considered a promising, clean, nearly inexhaustible source of energy. Power production by fusion micro-explosions of inertial confinement fusion (ICF) targets has been a long-term research goal since the invention of the first laser in 1960. The National Ignition Facility (NIF) is poised to take the next important step in the journey by beginning experiments researching ICF ignition. Ignition on NIF will be the culmination of over 30 years of ICF research on high-powered laser systems such as the Nova laser at Lawrence Livermore National Laboratory (LLNL) and the OMEGA laser at the University of Rochester, as well as smaller systems around the world. NIF is a 192-beam Nd-glass laser facility at LLNL that is more than 90% complete. The first cluster of 48 beams is operational in the laser bay, the second cluster is now being commissioned, and the beam path to the target chamber is being installed. The Project will be completed in 2009, and ignition experiments will start in 2010. When completed, NIF will produce up to 1.8 MJ of 0.35-μm light in highly shaped pulses required for ignition. It will have beam stability and control to higher precision than any other laser fusion facility. Experiments using one of the beams of NIF have demonstrated that NIF can meet its beam performance goals. The National Ignition Campaign (NIC) has been established to manage the ignition effort on NIF. NIC has all of the research and development required to execute the ignition plan and to develop NIF into a fully operational facility. NIF will explore the ignition space, including direct drive, 2ω ignition, and fast ignition, to optimize target efficiency for developing fusion as an energy source. In addition to efficient target performance, fusion energy requires significant advances in high-repetition-rate lasers and fusion reactor technology. The Mercury laser at LLNL is a high-repetition-rate Nd-glass laser for fusion energy driver development. Mercury

The national ignition facility (NIF) : A path to fusion energy

International Nuclear Information System (INIS)

Moses, E. I.

2007-01-01

Fusion energy has long been considered a promising clean, nearly inexhaustible source of energy. Power production by fusion micro-explosions of inertial confinement fusion (ICF) targets has been a long term research goal since the invention of the first laser in 1960. The NIF is poised to take the next important step in the journey by beginning experiments researching ICF ignition. Ignition on NIF will be the culmination of over thirty years of ICF research on high-powered laser systems such as the Nova laser at LLNL and the OMEGA laser at the University of Rochester as well as smaller systems around the world. NIF is a 192 beam Nd-glass laser facility at LLNL that is more than 90% complete. The first cluster of 48 beams is operational in the laser bay, the second cluster is now being commissioned, and the beam path to the target chamber is being installed. The Project will be completed in 2009 and ignition experiments will start in 2010. When completed NIF will produce up to 1.8 MJ of 0.35 μm light in highly shaped pulses required for ignition. It will have beam stability and control to higher precision than any other laser fusion facility. Experiments using one of the beams of NIF have demonstrated that NIF can meet its beam performance goals. The National Ignition Campaign (NIC) has been established to manage the ignition effort on NIF. NIC has all of the research and development required to execute the ignition plan and to develop NIF into a fully operational facility. NIF will explore the ignition space, including direct drive, 2ω ignition, and fast ignition, to optimize target efficiency for developing fusion as an energy source. In addition to efficient target performance, fusion energy requires significant advances in high repetition rate lasers and fusion reactor technology. The Mercury laser at LLNL is a high repetition rate Nd-glass laser for fusion energy driver development. Mercury uses state-o-the art technology such as ceramic laser slabs and light

The international magnetic fusion energy program

Energy Technology Data Exchange (ETDEWEB)

Fowler, T.K.

1988-10-06

In May of 1988, the long tradition of international cooperation in magnetic fusion energy research culminated in the initiation of design work on the International Thermonuclear Experimental Reactor (ITER). If eventually constructed in the 1990s, ITER would be the world's first magnetic fusion reactor. This paper discusses the background events that led to ITER and the present status of the ITER activity. This paper presents a brief summary of the technical, political, and organizational activities that have led to the creation of the ITER design activity. The ITER activity is now the main focus of international cooperation in magnetic fusion research and one of the largest international cooperative efforts in all of science. 2 refs., 12 figs.

Evaluation of DD and DT fusion fuel cycles for different fusion-fission energy systems

International Nuclear Information System (INIS)

Gohar, Y.

1980-01-01

A study has been carried out in order to investigate the characteristics of an energy system to produce a new source of fissile fuel for existing fission reactors. The denatured fuel cycles were used because it gives additional proliferation resistance compared to other fuel cycles. DT and DD fusion drivers were examined in this study with a thorium or uranium blanket for each fusion driver. Various fuel cycles were studied for light-water and heavy-water reactors. The cost of electricity for each energy system was calculated

Radio-frequency energy in fusion power generation

International Nuclear Information System (INIS)

Lawson, J.Q.; Becraft, W.R.; Hoffman, D.J.

1983-01-01

The history of radio-frequency (rf) energy in fusion experiments is reviewed, and the status of current efforts is described. Potential applications to tasks other than plasma heating are described, as are the research and development needs of rf energy technology

Office of Fusion Energy Sciences. A ten-year perspective (2015-2025)

Energy Technology Data Exchange (ETDEWEB)

None

2015-12-01

The vision described here builds on the present U.S. activities in fusion plasma and materials science relevant to the energy goal and extends plasma science at the frontier of discovery. The plan is founded on recommendations made by the National Academies, a number of recent studies by the Fusion Energy Sciences Advisory Committee (FESAC), and the Administration’s views on the greatest opportunities for U.S. scientific leadership.This report highlights five areas of critical importance for the U.S. fusion energy sciences enterprise over the next decade: 1) Massively parallel computing with the goal of validated whole-fusion-device modeling will enable a transformation in predictive power, which is required to minimize risk in future fusion energy development steps; 2) Materials science as it relates to plasma and fusion sciences will provide the scientific foundations for greatly improved plasma confinement and heat exhaust; 3) Research in the prediction and control of transient events that can be deleterious to toroidal fusion plasma confinement will provide greater confidence in machine designs and operation with stable plasmas; 4) Continued stewardship of discovery in plasma science that is not expressly driven by the energy goal will address frontier science issues underpinning great mysteries of the visible universe and help attract and retain a new generation of plasma/fusion science leaders; 5) FES user facilities will be kept world-leading through robust operations support and regular upgrades. Finally, we will continue leveraging resources among agencies and institutions and strengthening our partnerships with international research facilities.

ITER implementation and fusion energy research in China

International Nuclear Information System (INIS)

Zhao, Jing; Feng, Zhaoliang; Yang, Changchun

2015-01-01

ITER Project is jointly implemented by China, EU, India, Japan, Korea, Russian Federation and USA, under the coordination of Center Team of ITER International Fusion Energy Organization (IO-CT). Chinese fusion research related institutes and industrial enterprises are fully involved in the implementation of China contribution to the project under the leadership of ITER China Domestic Agency (CN-DA), together with IO-CT. The progresses of Procurement Packages (PA) allocated to China and the technical issues, especially on key technology development and schedule, QA/QC issues, are highlighted in this report. The specific enterprises carrying out different PAs are identified in order to make the increasing international manufactures and producers to ITER PAs know each other well for the successful implementation of ITER project. The participation of China to the management of IO-CT is also included, mainly from the governmental aspect and staff recruited from China. On the other hand, the domestic fusion researches, including upgrade of EAST, HL-2A Tokamaks in China, TBM program, the next step design activities for fusion energy power plant, namely, CFETR and training in this area, are also introduced for global cooperation for international fusion community. (author)

Opportunities in the Fusion Energy Sciences Program [Includes Appendix C: Topical Areas Characterization

Energy Technology Data Exchange (ETDEWEB)

None

1999-06-01

Recent years have brought dramatic advances in the scientific understanding of fusion plasmas and in the generation of fusion power in the laboratory. Today, there is little doubt that fusion energy production is feasible. The challenge is to make fusion energy practical. As a result of the advances of the last few years, there are now exciting opportunities to optimize fusion systems so that an attractive new energy source will be available when it may be needed in the middle of the next century. The risk of conflicts arising from energy shortages and supply cutoffs, as well as the risk of severe environmental impacts from existing methods of energy production, are among the reasons to pursue these opportunities.

Cold fusion, Alchemist's dream

International Nuclear Information System (INIS)

Clayton, E.D.

1989-09-01

In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D 2 molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D 2 fusion at low energies; fusion of deuterons into 4 He; secondary D+T fusion within the hydrogenated metal lattice; 3 He to 4 He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of 3 He/ 4 He

Sub-barrier fusion of Si+Si systems

Science.gov (United States)

Colucci, G.; Montagnoli, G.; Stefanini, A. M.; Bourgin, D.; Čolović, P.; Corradi, L.; Courtin, S.; Faggian, M.; Fioretto, E.; Galtarossa, F.; Goasduff, A.; Haas, F.; Mazzocco, M.; Scarlassara, F.; Stefanini, C.; Strano, E.; Urbani, M.; Szilner, S.; Zhang, G. L.

2017-11-01

The near- and sub-barrier fusion excitation function has been measured for the system 30Si+30Si at the Laboratori Nazionali di Legnaro of INFN, using the 30Si beam of the XTU Tandem accelerator in the energy range 47 - 90 MeV. A set-up based on a beam electrostatic deflector was used for detecting fusion evaporation residues. The measured cross sections have been compared to previous data on 28Si+28Si and Coupled Channels (CC) calculations have been performed using M3Y+repulsion and Woods-Saxon potentials, where the lowlying 2+ and 3- excitations have been included. A weak imaginary potential was found to be necessary to reproduce the low energy 28Si+28Si data. This probably simulates the effect of the oblate deformation of this nucleus. On the contrary, 30Si is a spherical nucleus, 30Si+30Si is nicely fit by CC calculations and no imaginary potential is needed. For this system, no maximum shows up for the astrophysical S-factor so that we have no evidence for hindrance, as confirmed by the comparison with CC calculations. The logarithmic derivative of the two symmetric systems highlights their different low energy trend. A difference can also be noted in the two barrier distributions, where the high-energy peak present in 28Si+28Si is not observed for 30Si+30Si, probably due to the weaker couplings in last case.

Sub-barrier fusion of Si+Si systems

Directory of Open Access Journals (Sweden)

Colucci G.

2017-01-01

Full Text Available The near- and sub-barrier fusion excitation function has been measured for the system 30Si+30Si at the Laboratori Nazionali di Legnaro of INFN, using the 30Si beam of the XTU Tandem accelerator in the energy range 47 - 90 MeV. A set-up based on a beam electrostatic deflector was used for detecting fusion evaporation residues. The measured cross sections have been compared to previous data on 28Si+28Si and Coupled Channels (CC calculations have been performed using M3Y+repulsion and Woods-Saxon potentials, where the lowlying 2+ and 3− excitations have been included. A weak imaginary potential was found to be necessary to reproduce the low energy 28Si+28Si data. This probably simulates the effect of the oblate deformation of this nucleus. On the contrary, 30Si is a spherical nucleus, 30Si+30Si is nicely fit by CC calculations and no imaginary potential is needed. For this system, no maximum shows up for the astrophysical S-factor so that we have no evidence for hindrance, as confirmed by the comparison with CC calculations. The logarithmic derivative of the two symmetric systems highlights their different low energy trend. A difference can also be noted in the two barrier distributions, where the high-energy peak present in 28Si+28Si is not observed for 30Si+30Si, probably due to the weaker couplings in last case.

The restructured fusion program and the role of alternative fusion concepts

International Nuclear Information System (INIS)

Perkins, L.J.

1996-01-01

This testimony to the subcommittee on Energy and the Environment of the U.S. House of Representatives's Committee on Science pushes for about 25% of the fusion budget to go to alternative fusion concepts. These concepts are: low density magnetic confinement, inertial confinement fusion, high density magnetic confinement, and non- thermonuclear and miscellaneous programs. Various aspects of each of these concepts are outlined

Fusion energy development at McDonnell Douglas: why and how

International Nuclear Information System (INIS)

Ard, W.B.

1985-01-01

The McDonnell Douglas Astronautics Company started a development program in fusion energy in 1974. This paper discusses the rationale for an industrial program in fusion energy and gives a brief account of the major activities that the company has been involved in during the course of this effort

Integrated Chamber Design for the Laser Inertial Fusion Energy (LIFE) Engine

International Nuclear Information System (INIS)

Latkowski, J.F.; Kramer, K.J.; Abbott, R.P.; Morris, K.R.; DeMuth, J.; Divol, L.; El-Dasher, B.; Lafuente, A.; Loosmore, G.; Reyes, S.; Moses, G.A.; Fratoni, M.; Flowers, D.; Aceves, S.; Rhodes, M.; Kane, J.; Scott, H.; Kramer, R.; Pantano, C.; Scullard, C.; Sawicki, R.; Wilks, S.; Mehl, M.

2010-01-01

The Laser Inertial Fusion Energy (LIFE) concept is being designed to operate as either a pure fusion or hybrid fusion-fission system. A key component of a LIFE engine is the fusion chamber subsystem. The present work details the chamber design for the pure fusion option. The fusion chamber consists of the first wall and blanket. This integrated system must absorb the fusion energy, produce fusion fuel to replace that burned in previous targets, and enable both target and laser beam transport to the ignition point. The chamber system also must mitigate target emissions, including ions, x-rays and neutrons and reset itself to enable operation at 10-15 Hz. Finally, the chamber must offer a high level of availability, which implies both a reasonable lifetime and the ability to rapidly replace damaged components. An integrated LIFE design that meets all of these requirements is described herein.

Integrated Chamber Design for the Laser Inertial Fusion Energy (LIFE) Engine

Energy Technology Data Exchange (ETDEWEB)

Latkowski, J F; Kramer, K J; Abbott, R P; Morris, K R; DeMuth, J; Divol, L; El-Dasher, B; Lafuente, A; Loosmore, G; Reyes, S; Moses, G A; Fratoni, M; Flowers, D; Aceves, S; Rhodes, M; Kane, J; Scott, H; Kramer, R; Pantano, C; Scullard, C; Sawicki, R; Wilks, S; Mehl, M

2010-12-07

The Laser Inertial Fusion Energy (LIFE) concept is being designed to operate as either a pure fusion or hybrid fusion-fission system. A key component of a LIFE engine is the fusion chamber subsystem. The present work details the chamber design for the pure fusion option. The fusion chamber consists of the first wall and blanket. This integrated system must absorb the fusion energy, produce fusion fuel to replace that burned in previous targets, and enable both target and laser beam transport to the ignition point. The chamber system also must mitigate target emissions, including ions, x-rays and neutrons and reset itself to enable operation at 10-15 Hz. Finally, the chamber must offer a high level of availability, which implies both a reasonable lifetime and the ability to rapidly replace damaged components. An integrated LIFE design that meets all of these requirements is described herein.

Materials handbook for fusion energy systems

Science.gov (United States)

Davis, J. W.; Marchbanks, M. F.

A materials data book for use in the design and analysis of components and systems in near term experimental and commercial reactor concepts has been created by the Office of Fusion Energy. The handbook is known as the Materials Handbook for Fusion Energy Systems (MHFES) and is available to all organizations actively involved in fusion related research or system designs. Distribution of the MHFES and its data pages is handled by the Hanford Engineering Development Laboratory (HEDL), while its direction and content is handled by McDonnell Douglas Astronautics Company — St. Louis (MDAC-STL). The MHFES differs from other handbooks in that its format is geared more to the designer and structural analyst than to the materials scientist or materials engineer. The format that is used organizes the handbook by subsystems or components rather than material. Within each subsystem is information pertaining to material selection, specific material properties, and comments or recommendations on treatment of data. Since its inception a little more than a year ago, over 80 copies have been distributed to over 28 organizations consisting of national laboratories, universities, and private industries.

Fusion-supported decentralized nuclear energy system

International Nuclear Information System (INIS)

Jassby, D.L.

1979-04-01

A decentralized nuclear energy system is proposed comprising mass-produced pressurized water reactors in the size range 10 to 300 MW (thermal), to be used for the production of process heat, space heat, and electricity in applications where petroleum and natural gas are presently used. Special attention is given to maximizing the refueling interval with no interim batch shuffling in order to minimize fuel transport, reactor downtime, and opportunity for fissile diversion. These objectives demand a substantial fissile enrichment (7 to 15%). The preferred fissile fuel is U-233, which offers an order of magnitude savings in ore requirements (compared with U-235 fuel), and whose higher conversion ratio in thermal reactors serves to extend the period of useful reactivity and relieve demand on the fissile breeding plants (compared with Pu-239 fuel). Application of the neutral-beam-driven tokamak fusion-neutron source to a U-233 breeding pilot plant is examined. This scheme can be extended in part to a decentralized fusion energy system, wherein remotely located large fusion reactors supply excess tritium to a distributed system of relatively small nonbreeding D-T reactors

Appropriate bare potentials for studying fusion induced by 6He

International Nuclear Information System (INIS)

Crema, E; Chamon, L.C; Gomes, P.R.S.

2007-01-01

Although there are some recent studies questioning the use of the same optical potential to explain simultaneously fusion and quasi-elastic experimental data [1] or even to explain deep sub-barrier- and above-barrier fusion [2], during the last decades, the bare nuclear interaction between the nuclei at near barrier energies has been widely represented by a frozen potential with a Woods-Saxon shape. Another well established fact is the strong dependence of nuclear reaction calculations on the choice of the primary interaction. Of course, comparison between data and theoretical calculations are strongly potential-dependent. So, the choice of an appropriate nuclear bare interaction between two colliding nuclei, although it is a difficult task, is a crucial step in the data interpretation. As one has not direct access to the true bare potential, some procedures have been developed in order to constrain the choice of the bare potential to be used. The first procedure is the analysis of the elastic scattering data within the context of an optical potential, where an imaginary potential is added to the real potential, in order to take into account the flux deviated from the elastic channel. The optical potential that gives the best fit to the elastic scattering data is then used to describe other reaction channels, even in coupled channel calculations including inelastic and transfer reactions in the coupling matrix. However, this kind of calculation suffers from several inconsistencies. Another procedure that has been widely used to obtain the bare potential is the fit of the high-energy fusion data by a single barrier penetration model (BPM). However this method also has its uncertainties, since there might be channels that hinder the fusion cross section at energies near and above the Coulomb barrier. Hence, the bare potential extracted through this method can be contaminated by different processes. The derivation of experimental barrier distributions probably is the

Correlations between transfer and fusion in heavy ion collisions at the Coulomb barrier

International Nuclear Information System (INIS)

Bellwied, R.

1989-03-01

For the fusion of heavy atomic nuclei the nuclear-charge product exceeds Z 1 Z 2 =1600 in experiments at the Coulomb barrier a dynamical hindrance was detected. For the study of all binary reaction channels first 86 Kr induced reactions with 76 Ge, 104 Ru, and 130 Te were radiochemically studied. The relative to the fusion still unhindered system Kr+Ge shows beside the fusion only the transfer of few nucleons between projectile and target. In the reactions with Ru and Te (onsetting fusion hindrance) goes indeed a certain part (about 20%) of the missing fusion cross section in reactions with large mass flux, on the other hand however a sudden increasing of the quasi-elastic transfer of few nucleons strikes which fits well into the trend of the literature data for lighter and heavier systems and signalizes a sharply localized correlation between the vanishing of the fusion and the increasing of the transfer. In order to study further this threshold behaviour and to get additional kinematical informations on the binary reaction channels the reactions 96 Zr+ 90 Zr and 124 Sn+ 96 Zr were measured at the magnetic spectrometer of the GSI. With the spectrometer it is contrarily to the radiochemical experiments possible to determine fourfold differential cross section distributions. The sudden increasing of the cross section for quasi-elastic transfer at the threshold for fusion hindrance is completely confirmed whereby from measurements of the energy loss in the exit channel follows that (with lower weight) also complex transfer channels with essential energy damping are formed. By these experiments it has been shown for the first time that the dynamical fusion hindrance already onsets before the collisional partners reach the barrier. (orig./HSI) [de

Energy for the long run: fission or fusion

International Nuclear Information System (INIS)

Kulcinski, G.L.; Kessler, G.; Holdren, J.; Haefele, W.

1979-01-01

The alternatives of the most likely and controversial long-range energy sources, fusion and fast-breeder fission, are compared in several areas: potential biological and social hazards, costs of research and development, capital costs, technical complexity, and time factors. It is concluded that from biological and social hazards standpoint, fusion is preferable to fast-breeder fission reactors; however, the LMFBR has already passed on the threshold of scientific and engineering feasibility. It is pointed out that LMFBR should not be compared with short-term energy sources, e.g. coal or oil, but should be compared only with other long-term energy sources, e.g. other types of breeder reactors

Towards a unified description of light ion fusion cross section excitation functions

International Nuclear Information System (INIS)

Zimmer, K.W.

1995-01-01

A description of light heavy-ion fusion, taking into account both entrance-channel characteristics and compound-nucleus properties, is derived within a unified theory of nuclear reactions. The dependence of the imaginary fusion potential on the level density of the compound nucleus is revealed. The 12 C + 12 C, 12 C + 14 N, 10 B + 16 O and 16 O + 16 O fusion cross sections are calculated for E cm ≤ 120 MeV and compared with experimental data. The excitation energy dependence of the level-density parameter of 24 Mg, 26 Al and 32 S is inferred below 5 MeV/A. A realistic nuclear level-density model, describing the experimental level-density parameters of highly excited nuclei, is shown to be consistent with both the global features and details of the fusion cross section. 12 C + 12 C and 16 O + 16 O fusion cross section oscillations are predicted at large excitation energies, reflecting the structure of the level density of the highly excited light compound nuclei. Differences of the 12 C + 14 N and 10 B + 16 O fusion reaction mechanisms are discussed in terms of specific entrance-channel characteristics. (orig.)

Towards a unified description of light ion fusion cross section excitation functions

International Nuclear Information System (INIS)

Zimmer, K.W.; Rebel, H.

1994-10-01

A description of light heavy-ion fusion, taking into account both entrace-channel characteristics and compound-nucleus properties, is derived within a unified theory of nuclear reactions. The dependence of the imaginary fusion potential on the level density of the compound nucleus is revealed. The 12 C+ 12 C, 12 C+ 14 N, 10 B+ 16 O and 16 O+ 16 O fusion cross sections are calculated for E cm ≤120 MeV and compared with experimental data. The excitation energy dependence of the level-density parameter of 24 Mg, 26 Al and 32 S is inferred below 5 MeV/A. A realistic nuclear level-density model, describing the experimental level-density parameters of highly excited nuclei, is shown to be consistent with both the global features and details of the fusion cross section. 12 C+ 12 C and 16 O+ 16 O fusion cross section oscillations are predicted at large excitation energies, reflecting the structure of the level density of the highly excited light compound nuclei. Differences of the 12 C+ 14 N and 10 B+ 16 O fusion reaction mechanisms are discussed in terms of specific entrance-channel characteristics. (orig.)

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

Role of nuclear fusion in future energy systems and the environment under future uncertainties

International Nuclear Information System (INIS)

Tokimatsu, Koji; Fujino, Jun'ichi; Konishi, Satoshi; Ogawa, Yuichi; Yamaji, Kenji

2003-01-01

Debates about whether or not to invest heavily in nuclear fusion as a future innovative energy option have been made within the context of energy technology development strategies. This is because the prospects for nuclear fusion are quite uncertain and the investments therefore carry the risk of quite large regrets, even though investment is needed in order to develop the technology. The timeframe by which nuclear fusion could become competitive in the energy market has not been adequately studied, nor has roles of the nuclear fusion in energy systems and the environment. The present study has two objectives. One is to reveal the conditions under which nuclear fusion could be introduced economically (hereafter, we refer to such introductory conditions as breakeven prices) in future energy systems. The other objective is to evaluate the future roles of nuclear fusion in energy systems and in the environment. Here we identify three roles that nuclear fusion will take on when breakeven prices are achieved: (i) a portion of the electricity market in 2100, (ii) reduction of annual global total energy systems cost, and (iii) mitigation of carbon tax (shadow price of carbon) under CO 2 constraints. Future uncertainties are key issues in evaluating nuclear fusion. Here we treated the following uncertainties: energy demand scenarios, introduction timeframe for nuclear fusion, capacity projections of nuclear fusion, CO 2 target in 2100, capacity utilization ratio of options in energy/environment technologies, and utility discount rates. From our investigations, we conclude that the presently designed nuclear fusion reactors may be ready for economical introduction into energy systems beginning around 2050-2060, and we can confirm that the favorable introduction of the reactors would reduce both the annual energy systems cost and the carbon tax (the shadow price of carbon) under a CO 2 concentration constraint

Contributions of the National Ignition Facility to the development of Inertial Fusion Energy

International Nuclear Information System (INIS)

Tobin, M.; Logan, G.; Diaz De La Rubia, T.; Schrock, V.; Schultz, K.; Tokheim, R.; Abdou, M.; Bangerter, R.

1994-06-01

The Department of Energy is proposing to construct the National Ignition Facility (NIF) to embark on a program to achieve ignition and modest gain in the laboratory early in the next century. The NIF will use a ≥ 1.8-MJ, 0.35-mm laser with 192 independent beams, a fifty-fold increase over the energy of the Nova laser. System performance analyses suggest yields as great as 20 MJ may be achievable. The benefits of a micro-fusion capability in the laboratory include: essential contributions to defense programs, resolution of important Inertial Fusion Energy issues, and unparalleled conditions of energy density for basic science and technology research. We have begun to consider the role the National Ignition Facility will fill in the development of Inertial Fusion Energy. While the achievement of ignition and gain speaks for itself in terms of its impact on developing IFE, we believe there are areas of IFE development such as fusion power technology, IFE target design and fabrication, and understanding chamber dynamics, that would significantly benefit from NIF experiments. In the area of IFE target physics, ion targets will be designed using the NIF laser, and feasibility of high gain targets will be confirmed. Target chamber dynamics experiments will benefit from x-ray and debris energies that mimic in-IFE-chamber conditions. Fusion power technology will benefit from using single-shot neutron yields to measure spatial distribution of neutron heating, activation, and tritium breeding in relevant materials. IFE target systems will benefit from evaluating low-cost target fabrication techniques by testing such targets on NIF. Additionally, we believe it is feasible to inject up to four targets and engage them with the NIF laser by triggering the beams in groups of ∼50 separated in time by ∼0.1 s. Sub-ignition neutron yields would allow an indication of symmetry achieved in such proof-of-principle rep-rate experiments

Inertial fusion energy with krypton fluoride lasers

International Nuclear Information System (INIS)

Sethian, J.D.

2010-01-01

Complete text of publication follows. We are developing the science and technologies needed for a practical fusion energy source using high energy krypton fluoride (KrF) lasers. The physics basis for this work is a family of simulations that exploit the unique advantages of KrF lasers. KrF lasers provide uniform enough laser light to illuminate the capsule directly, greatly improving the laser-target coupling efficiency, as well as simplifying the target design. KrF's shorter wavelength allows higher ablation pressures and helps suppress laser-plasma instabilities. These advantages are being demonstrated on the NRL Nike KrF laser facility. A particularly promising approach is shock ignition, in which a high intensity laser pulse drives an intense shock at peak compression. Simulations with experimentally benchmarked codes predict a 1 MJ KrF laser can produce 200 MJ of pure fusion energy. We have similarly advanced the laser technology. We have developed a KrF laser, using technologies that scale to a reactor beamline, that fires 5 times per second for long duration runs and is projected be efficient enough for a reactor. The science and the technology for the key components are developed at the same time as part of a coherent system. A multi-institutional team from industry, national labs, and universities has developed credible solutions for these components. This includes methods to fabricate the spherical pellets on mass production basis, a means to repetitively inject the capsules into the chamber and precisely hit them with the laser, scaled tests to develop the laser optics, and designs for the reaction vessel. Based on these advances NRL and its collaborators have formulated a three stage plan that could lead to practical fusion energy on a much faster time scale than currently believed. Stage I develops full scale components: a laser beam line, target factory and injector, and chamber technologies. Stage II is the Fusion Test Facility (FTF). Simulations

Coupling of laser energy into plasma channels

International Nuclear Information System (INIS)

Dimitrov, D. A.; Giacone, R. E.; Bruhwiler, D. L.; Busby, R.; Cary, J. R.; Geddes, C. G. R.; Esarey, E.; Leemans, W. P.

2007-01-01

Diffractive spreading of a laser pulse imposes severe limitations on the acceleration length and maximum electron energy in the laser wake field accelerator (LWFA). Optical guiding of a laser pulse via plasma channels can extend the laser-plasma interaction distance over many Rayleigh lengths. Energy efficient coupling of laser pulses into and through plasma channels is very important for optimal LWFA performance. Results from simulation parameter studies on channel guiding using the particle-in-cell (PIC) code VORPAL [C. Nieter and J. R. Cary, J. Comput. Phys. 196, 448 (2004)] are presented and discussed. The effects that density ramp length and the position of the laser pulse focus have on coupling into channels are considered. Moreover, the effect of laser energy leakage out of the channel domain and the effects of tunneling ionization of a neutral gas on the guided laser pulse are also investigated. Power spectral diagnostics were developed and used to separate pump depletion from energy leakage. The results of these simulations show that increasing the density ramp length decreases the efficiency of coupling a laser pulse to a channel and increases the energy loss when the pulse is vacuum focused at the channel entrance. Then, large spot size oscillations result in increased energy leakage. To further analyze the coupling, a differential equation is derived for the laser spot size evolution in the plasma density ramp and channel profiles are simulated. From the numerical solution of this equation, the optimal spot size and location for coupling into a plasma channel with a density ramp are determined. This result is confirmed by the PIC simulations. They show that specifying a vacuum focus location of the pulse in front of the top of the density ramp leads to an actual focus at the top of the ramp due to plasma focusing, resulting in reduced spot size oscillations. In this case, the leakage is significantly reduced and is negligibly affected by ramp length

Fusion energy 1996. V. 1. Proceedings of the 16. international conference

International Nuclear Information System (INIS)

1997-01-01

The sixteenth International Atomic Energy Agency (IAEA) Fusion Energy Conference was held in Montreal, Canada, from 7 to 11 October 1996. The conference, which was attended by some 500 participants from over thirty countries and two international organizations, was organized by the IAEA in cooperation with the Centre canadien de fusion magnetique and the Canadian National Fusion Program. Some 270 papers were presented in 19 oral and 8 poster sessions on magnetic and inertial confinement systems, plasma theory, computer modelling, alternative confinement approaches, fusion technology and future experiments. Refs, figs, tabs

Fusion energy 1996. V. 3. Proceedings of the 16. international conference

International Nuclear Information System (INIS)

1997-01-01

The sixteenth International Atomic Energy Agency (IAEA) Fusion Energy Conference was held in Montreal, Canada, from 7 to 11 October 1996. The conference, which was attended by some 500 participants from over thirty countries and two international organizations, was organized by the IAEA in cooperation with the Centre canadien de fusion magnetique and the Canadian National Fusion Program. Some 270 papers were presented in 19 oral and 8 poster sessions on magnetic and inertial confinement systems, plasma theory, computer modelling, alternative confinement approaches, fusion technology and future experiments

Systems-design and energy-balance considerations for impact fusion

International Nuclear Information System (INIS)

Krakowski, R.A.; Miller, R.L.

1979-01-01

Areas of concern and potential problems for impact fusion are qualitatively considered within an overall systems context. A parametric and qualitative description of the general energy balance and systems considerations for an Impact Fusion Reactor (IFR) design is discussed. Reactor systems design considerations for an IFR are presented. An attempt to assess the IFR viability is made based on highly simplified but limiting projectile-target energy balances and thermonuclear burn models

Comparison of interbody fusion approaches for disabling low back pain.

Science.gov (United States)

Hacker, R J

1997-03-15

This is a study comparing two groups of patients surgically treated for disabling low back pain. One group was treated with lumbar anteroposterior fusion (360 degrees fusion), the other with posterior lumbar interbody fusion and an interbody fixation device. To determine which approach provided the best and most cost-effective outcome using similar patient selection criteria. Others have shown that certain patients with disabling low back pain benefit from lumbar fusion. Although rarely reported, the costs of different surgical treatments appear to vary significantly, whereas the patient outcome may vary little. Since 1991, 75 patients have been treated Starting in 1993, posterior lumbar interbody fusion BAK was offered to patients as an alternative to 360 degrees fusion. The treating surgeon reviewed the cases. The interbody fixation device used (BAK; Spine-Tech, Inc., Minneapolis, MN) was part of a Food and Drug Administration study. Patient selection criteria included examination, response to conservative therapy, imaging, psychological profile, and discography. North American Spine Society outcome questionnaires, BAK investigation data radiographs, chart entries, billing records and patient interviews were the basis for assessment. Age, sex compensable injury history and history of previous surgery were similar. Operative time; blood loss, hospitalization time, and total costs were significantly different. There was a quicker return to work and closure of workers compensation claims for the posterior lumbar interbody fusion-BAK group. Patient satisfaction was comparable at last follow-up. Posterior lumbar interbody fusion-BAK achieves equal patient satisfaction but fiscally surpasses the 360 degrees fusion approach. Today's environment of regulated medical practice requires the surgeon to consider cost effectiveness when performing fusion for low back pain.

Generation of a pulsed low-energy electron beam using the channel spark device

Energy Technology Data Exchange (ETDEWEB)

Elgarhy, M. A. I., E-mail: elgarhy@azhar.edu.eg; Hassaballa, S. E.; Rashed, U. M.; ElSabbagh, M. M.; Saudy, A. H. [Physics Department, Faculty of Science, Al-Azhar University, Cairo (Egypt); Soliman, H. M. [Plasma and Nuclear Fusion Department, Atomic Energy Authority, Enshas (Egypt)

2015-12-15

For the generation of low-energy electron beam, the design and characteristics of channel spark discharge (CSD) operating at a low voltage are presented in this paper. The discharge voltage, discharge current, X-ray emissions, and electron beam current were experimentally determined. The effects of the applied voltage, working gas pressure, and external capacitance on the CSD and beam parameters were measured. At an applied voltage of 11 kV, an oxygen gas pressure of 25 mTorr, and an external capacitance of 16.45 nF, the maximum measured current was 900 A. The discharge current increased with the increase in the pressure and capacitance, while its periodic time decreased with the increase in the pressure. Two types of the discharge were identified and recorded: the hollow cathode discharge and the conduction discharge. A Faraday cup was used to measure the beam current. The maximum measured beam current was 120 A, and the beam signal exhibited two peaks. The increase in both the external capacitance and the applied discharge voltage increased the maximum electron beam current. The electron-beam pulse time decreased with the increase in the gas pressure at a constant voltage and increased with the decrease in the applied discharge voltage. At an applied voltage of 11 kV and an oxygen gas pressure of 15 mTorr, the maximum beam energy was 2.8 keV. The X-ray signal intensity decreased with the increase in the gas pressure and increased with the increase in the capacitance.

Energy-Efficient Channel Estimation in MIMO Systems

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available The emergence of MIMO communications systems as practical high-data-rate wireless communications systems has created several technical challenges to be met. On the one hand, there is potential for enhancing system performance in terms of capacity and diversity. On the other hand, the presence of multiple transceivers at both ends has created additional cost in terms of hardware and energy consumption. For coherent detection as well as to do optimization such as water filling and beamforming, it is essential that the MIMO channel is known. However, due to the presence of multiple transceivers at both the transmitter and receiver, the channel estimation problem is more complicated and costly compared to a SISO system. Several solutions have been proposed to minimize the computational cost, and hence the energy spent in channel estimation of MIMO systems. We present a novel method of minimizing the overall energy consumption. Unlike existing methods, we consider the energy spent during the channel estimation phase which includes transmission of training symbols, storage of those symbols at the receiver, and also channel estimation at the receiver. We develop a model that is independent of the hardware or software used for channel estimation, and use a divide-and-conquer strategy to minimize the overall energy consumption.

Response to FESAC survey, non-fusion connections to Fusion Energy Sciences. Applications of the FES-supported beam and plasma simulation code, Warp

Energy Technology Data Exchange (ETDEWEB)

Friedman, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Grote, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vay, J. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-05-29

The Fusion Energy Sciences Advisory Committee’s subcommittee on non-fusion applications (FESAC NFA) is conducting a survey to obtain information from the fusion community about non-fusion work that has resulted from their DOE-funded fusion research. The subcommittee has requested that members of the community describe recent developments connected to the activities of the DOE Office of Fusion Energy Sciences. Two questions in particular were posed by the subcommittee. This document contains the authors’ responses to those questions.

Fusion energy for the 21st century

International Nuclear Information System (INIS)

Harris, J.H.

1999-01-01

Fusion reactions like those that power the stars have the potential of providing bulk electricity generation with reduced emissions and low radioactive hazard, but pose many challenges in physics and technology. The H-1 Heliac Major National Research Facility now being developed offers Australian scientists and engineers an opportunity to participate in the collaborative international fusion research program. Work on H-1NF contributes not only to the realisation of fusion power, but offers the stimulus and opportunity for advanced training and the development of spin-off technology

Exploring the Inert Doublet Model through the dijet plus missing transverse energy channel at the LHC

Directory of Open Access Journals (Sweden)

P. Poulose

2017-02-01

Full Text Available In this study of the Inert Doublet Model (IDM, we propose that the dijet + missing transverse energy channel at the Large Hadron Collider (LHC will be an effective way of searching for the scalar particles of the IDM. This channel receives contributions from gauge boson fusion, and t-channel production, along with contributions from H+ associated production. We perform the analysis including study of the Standard Model (SM background with assumed systematic uncertainty, and optimise the selection criteria employing suitable cuts on the kinematic variables to maximise the signal significance. We find that with high luminosity option of the LHC, this channel has the potential to probe the IDM in the mass range of up to about 400 GeV, which is not accessible through other leptonic channels. In a scenario with light dark matter of mass about 65 GeV, charged Higgs in the mass range of around 200 GeV provides the best possibility with a signal significance of about 2σ at an integrated luminosity of about 3000 fb−1.

Rugged Packaging for Damage Resistant Inertial Fusion Energy Optics

Energy Technology Data Exchange (ETDEWEB)

Stelmack, Larry

2003-11-17

The development of practical fusion energy plants based on inertial confinement with ultraviolet laser beams requires durable, stable final optics that will withstand the harsh fusion environment. Aluminum-coated reflective surfaces are fragile, and require hard overcoatings resistant to contamination, with low optical losses at 248.4 nanometers for use with high-power KrF excimer lasers. This program addresses the definition of requirements for IFE optics protective coatings, the conceptual design of the required deposition equipment according to accepted contamination control principles, and the deposition and evaluation of diamondlike carbon (DLC) test coatings. DLC coatings deposited by Plasma Immersion Ion Processing were adherent and abrasion-resistant, but their UV optical losses must be further reduced to allow their use as protective coatings for IFE final optics. Deposition equipment for coating high-performance IFE final optics must be designed, constructed, and operated with contamination control as a high priority.

Fusion energy in context: its fitness for the long term

International Nuclear Information System (INIS)

Holdren, J.P.

1978-01-01

Long-term limits to growth in energy will be imposed not by inability to expand supply, but by the rising environmental and social costs of doing so. These costs will therefore be cental issues in choosing long-term options. Fusion, like solar energy, is not one possibility but many, some with very attractive environmental characteristics and others perhaps little better in these regards than fission. None of the fusion options will be cheap, and none is likely to be widely available before the year 2010. The most attractive forms of fusion may require greater investments of time and money to achieve, but they are the real reason for wanting fusion at all

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

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.

The ICRH tokamak fusion test reactor

International Nuclear Information System (INIS)

Perkins, F.W.

1976-01-01

A Tokamak Fusion Test Reactor where the ion are maintained at Tsub(i) approximately 20keV>Tsub(e) approximately 7keV by ion-cyclotron resonance heating is shown to produce an energy amplification of Q>2 provided the principal ion energy loss channel is via collisional transfer to the electrons. Such a reactor produces 19MW of fusion power to the electrons. Such a reactor produces 19MW of fusion power and requires a 50MHz radio-frequency generator capable of 50MW peak power; it is otherwise compatible with the conceptual design for the Princeton TFTR. The required n tausub(E) values for electrons and ions are respectively ntausub(Ee)>1.5.10 13 cm -3 -sec and ntausub(Ei)>4.10 13 cm -3 -sec. The principal areas where research is needed to establish this concept are: tokamak transport calculations, ICRH physics, trapped-particle instability energy losses, tokamak equilibria with high values of βsub(theta), and, of course, impurities

Outline of cold nuclear fusion reaction

International Nuclear Information System (INIS)

Tachikawa, Enzo

1991-01-01

In 2010, as the total supply capacity of primary energy, 666 million liter is anticipated under the measures of thorough energy conservation. The development of energy sources along the energy policy based on environment preservation, safety, the quantity of resources and economy is strongly demanded. The nuclear power generation utilizing nuclear fission has been successfully carried out. As the third means of energy production, the basic research and technical development have been actively advanced on the energy production utilizing nuclear fusion reaction. The main object of the nuclear fusion research being advanced now is D-D reaction and D-T reaction. In order to realize low temperature nuclear fusion reaction, muon nuclear fusion has been studied so far. The cold nuclear fusion reaction by the electrolysis of heavy water has been reported in 1989, and its outline is ixplained in this report. The trend of the research on cold nuclear fusion is described. But the possibility of cold nuclear fusion as an energy source is almost denied. (K.I.)

The effect of low energy helium ion irradiation on tungsten-tantalum (W-Ta) alloys under fusion relevant conditions

Science.gov (United States)

Gonderman, S.; Tripathi, J. K.; Novakowski, T. J.; Sizyuk, T.; Hassanein, A.

2017-08-01

Currently, tungsten remains the best candidate for plasma-facing components (PFCs) for future fusion devices because of its high melting point, low erosion, and strong mechanical properties. However, continued investigation has shown tungsten to undergo severe morphology changes under fusion-like conditions. These results motivate the study of innovative PFC materials which are resistant to surface morphology evolution. The goal of this work is to examine tungsten-tantalum (W-Ta) alloys, a potential PFC material, and their response to low energy helium ion irradiation. Specifically, W-Ta samples are exposed to 100 eV helium irradiations with a flux of 1.15 × 1021 ions m-2 s-1, at 873 K, 1023 K, and 1173 K for 1 h duration. Scanning electron microscopy (SEM) reveals significant changes in surface deterioration due to helium ion irradiation as a function of both temperature and tantalum concentration in W-Ta samples. X-Ray Diffraction (XRD) studies show a slight lattice parameter expansion in W-Ta alloy samples compared to pure W samples. The observed lattice parameter expansion in W-Ta alloy samples (proportional to increasing Ta wt.% concentrations) reflect significant differences observed in the evolution of surface morphology, i.e., fuzz development processes for both increasing Ta wt.% concentration and target temperature. These results suggest a correlation between the observed morphology differences and the induced crystal structure change caused by the presence of tantalum. Shifts in the XRD peaks before and after 100 eV helium irradiation with a flux of 1.15 × 1021 ions m-2 s-1, 1023 K, for 1 h showed a significant difference in the magnitude of the shift. This has suggested a possible link between the atomic spacing of the material and the accumulated damage. Ongoing research is needed on W-Ta alloys and other innovative materials for their application as irradiation resistant materials in future fusion or irradiation environments.

Measurements of fusion cross section for 12C +63,65 Cu systems

International Nuclear Information System (INIS)

Rocha, C.A. da.

1987-01-01

Cross-section measurements for nuclear fusion in the 12 C+ 63.65 Cu system, at 12 C energy range from 0.9 to 1.8 times the Coulomb barrier are presented. In order to detect and to obtain the mass identification of the evaporation residues following the fusion process, the time of flight method was adopted in conjunction with an eletrostatic deflector capable of separating the evaporation residues from the beam particles. The limitation and advantadges of this method of measurement are discussed. The excitation functions were analysed using the unidimensional barrier penetration model with different nuclear potentials. Theoretical fusion cross-section values obtained from this analysis were systematically smaller than our measured values, in the energy region below the Coulomb barrier. In order to discover which channel enhances the fusion cross-section in this region, a coupled channel calculation was performed, with the CCFUS code. The experimental data for the above reactions were compared with the systems 16.18 O+ 63.65 Cu, measured by our group. In this comparison, it was noted that the systems 12 C+ 63.65 Cu, have greater fusion cross section below the Coulomb barrier. The comparison of velocity spectra of the evaporated residues for the two systems shows that 12 C+ 63 Cu has a strong reaction channel that was not present in the 12 C+ 65 Cu system. (author) [pt

Quantum and Private Capacities of Low-Noise Channels

Science.gov (United States)

Leditzky, Felix; Leung, Debbie; Smith, Graeme

2018-04-01

We determine both the quantum and the private capacities of low-noise quantum channels to leading orders in the channel's distance to the perfect channel. It has been an open problem for more than 20 yr to determine the capacities of some of these low-noise channels such as the depolarizing channel. We also show that both capacities are equal to the single-letter coherent information of the channel, again to leading orders. We thus find that, in the low-noise regime, superadditivity and degenerate codes have a negligible benefit for the quantum capacity, and shielding does not improve the private capacity beyond the quantum capacity, in stark contrast to the situation when noisier channels are considered.

Fission, fusion and the energy crisis

Energy Technology Data Exchange (ETDEWEB)

Hunt, S E [Aston Univ., Birmingham (UK)

1980-01-01

The subject is covered in chapters, entitled: living on capital (energy reserves and consumption forecasts); the atom and its nucleus, mass and energy; fission and the bomb; the natural uranium reactor; enriched reactors; control and safety; long-term economics (the breeder reactions and nuclear fuel reserves); short-term economics (cost per kilowatt hour); national nuclear power programmes; nuclear power and the environment (including reprocessing, radioactive waste management, public relations); renewable energy sources; the fusion programme; summary and comment.

Typical performance of regular low-density parity-check codes over general symmetric channels

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Toshiyuki [Department of Electronics and Information Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo 192-0397 (Japan); Saad, David [Neural Computing Research Group, Aston University, Aston Triangle, Birmingham B4 7ET (United Kingdom)

2003-10-31

Typical performance of low-density parity-check (LDPC) codes over a general binary-input output-symmetric memoryless channel is investigated using methods of statistical mechanics. Relationship between the free energy in statistical-mechanics approach and the mutual information used in the information-theory literature is established within a general framework; Gallager and MacKay-Neal codes are studied as specific examples of LDPC codes. It is shown that basic properties of these codes known for particular channels, including their potential to saturate Shannon's bound, hold for general symmetric channels. The binary-input additive-white-Gaussian-noise channel and the binary-input Laplace channel are considered as specific channel models.

Typical performance of regular low-density parity-check codes over general symmetric channels

International Nuclear Information System (INIS)

Tanaka, Toshiyuki; Saad, David

2003-01-01

Typical performance of low-density parity-check (LDPC) codes over a general binary-input output-symmetric memoryless channel is investigated using methods of statistical mechanics. Relationship between the free energy in statistical-mechanics approach and the mutual information used in the information-theory literature is established within a general framework; Gallager and MacKay-Neal codes are studied as specific examples of LDPC codes. It is shown that basic properties of these codes known for particular channels, including their potential to saturate Shannon's bound, hold for general symmetric channels. The binary-input additive-white-Gaussian-noise channel and the binary-input Laplace channel are considered as specific channel models

Fusion Energy Division annual progress report, period ending December 31, 1989

Energy Technology Data Exchange (ETDEWEB)

Sheffield, J.; Baker, C.C.; Saltmarsh, M.J.

1991-07-01

The Fusion Program of Oak Ridge National Laboratory (ORNL) carries out research in most areas of magnetic confinement fusion. The program is directed toward the development of fusion as an energy source and is a strong and vital component of both the US fusion program and the international fusion community. Issued as the annual progress report of the ORNL Fusion Energy Division, this report also contains information from components of the Fusion Program that are carried out by other ORNL organizations (about 15% of the program effort). The areas addressed by the Fusion Program and discussed in this report include the following: Experimental and theoretical research on magnetic confinement concepts, engineering and physics of existing and planned devices, including remote handling, development and testing of diagnostic tools and techniques in support of experiments, assembly and distribution to the fusion community of databases on atomic physics and radiation effects, development and testing of technologies for heating and fueling fusion plasmas, development and testing of superconducting magnets for containing fusion plasmas, development and testing of materials for fusion devices, and exploration of opportunities to apply the unique skills, technology, and techniques developed in the course of this work to other areas. Highlights from program activities are included in this report.

Fusion Energy Division annual progress report, period ending December 31, 1989

International Nuclear Information System (INIS)

Sheffield, J.; Baker, C.C.; Saltmarsh, M.J.

1991-07-01

The Fusion Program of Oak Ridge National Laboratory (ORNL) carries out research in most areas of magnetic confinement fusion. The program is directed toward the development of fusion as an energy source and is a strong and vital component of both the US fusion program and the international fusion community. Issued as the annual progress report of the ORNL Fusion Energy Division, this report also contains information from components of the Fusion Program that are carried out by other ORNL organizations (about 15% of the program effort). The areas addressed by the Fusion Program and discussed in this report include the following: Experimental and theoretical research on magnetic confinement concepts, engineering and physics of existing and planned devices, including remote handling, development and testing of diagnostic tools and techniques in support of experiments, assembly and distribution to the fusion community of databases on atomic physics and radiation effects, development and testing of technologies for heating and fueling fusion plasmas, development and testing of superconducting magnets for containing fusion plasmas, development and testing of materials for fusion devices, and exploration of opportunities to apply the unique skills, technology, and techniques developed in the course of this work to other areas. Highlights from program activities are included in this report

How to improve the irradiation conditions for the International Fusion Materials Irradiation Facility

CERN Document Server

Daum, E

2000-01-01

The accelerator-based intense D-Li neutron source International Fusion Materials Irradiation Facility (IFMIF) provides very suitable irradiation conditions for fusion materials development with the attractive option of accelerated irradiations. Investigations show that a neutron moderator made of tungsten and placed in the IFMIF test cell can further improve the irradiation conditions. The moderator softens the IFMIF neutron spectrum by enhancing the fraction of low energy neutrons. For displacement damage, the ratio of point defects to cascades is more DEMO relevant and for tritium production in Li-based breeding ceramic materials it leads to a preferred production via the sup 6 Li(n,t) sup 4 He channel as it occurs in a DEMO breeding blanket.

Nuclear design of a very-low-activation fusion reactor

International Nuclear Information System (INIS)

Cheng, E.T.; Hopkins, G.R.

1983-06-01

An investigation was conducted to study the nuclear design aspects of using very-low-activation materials, such as SiC, MgO, and aluminum for fusion-reactor first wall, blanket, and shield applications. In addition to the advantage of very-low radioactive inventory, it was found that the very-low-activation fusion reactor can also offer an adequate tritium-breeding ratio and substantial amount of blanket nuclear heating as a conventional-material-structured reactor does. The most-stringent design constraint found in a very-low-activation fusion reactor is the limited space available in the inboard region of a tokamak concept for shielding to protect the superconducting toroidal field coil. A reference design was developed which mitigates the constraint by adopting a removable tungsten shield design that retains the inboard dimensions and gives the same shield performance as the reference STARFIRE tokamak reactor design

Materials studies for magnetic fusion energy applications at low temperatures. VIII. Technical reports

International Nuclear Information System (INIS)

Reed, R.P.

1985-05-01

This report contains results of a research progam to produce material property data that will facilitte design and development of cryogenic structures for the superconducting magnets of magnetic fusion energy power plants and prototypes. Research results for 1984 are summarized in an initial ''Highlights of Results'' section and reported in detail in the technical papers that form the main body of this report. The technical papers are presented under four headings reflecting the main program areas: Welding, Nonmetallics, Structural Alloys, and Technology Transfer. Objectives, approaches, and achievements are summarized in an introduction to each program area

Channeling and dechanneling at high energy

International Nuclear Information System (INIS)

Carrigan, R.A. Jr.

1987-01-01

The possibility of using channeling as a tool for high energy particle physics has now been extensively investigated. Bent crystals have been used as an accelerator extraction element and for particle deflection. Applications as accelerating devices have been discussed but appear remote. The major advantage in using a bent crystal rather than a magnet is the large deflection that can be achieved in a short length. The major disadvantage is the low transmission. A good understanding of dechanneling is important for applications. 43 refs., 1 fig., 3 tabs

Analytic description of the fusion and fission processes through compact quasi-molecular shapes

International Nuclear Information System (INIS)

Royer, G.; Normand, C.; Druet, E.

1997-01-01

Recent studies have shown that the characteristics of the entrance and exit channels through compact quasi-molecular shapes are compatible with the experimental data on fusion, fission and cluster radioactivity when the deformation energy is determined within a generalized liquid drop model. Analytic expressions allowing to calculate rapidly the main characteristics of this deformation path through necked shapes with quasi-spherical ends are presented now; namely formulas for the fusion and fission barrier heights, the fusion barrier radius, the symmetric fission barriers and the proximity energy. (author)

Energy conversion device with support member having pore channels

Science.gov (United States)

Routkevitch, Dmitri [Longmont, CO; Wind, Rikard A [Johnstown, CO

2014-01-07

Energy devices such as energy conversion devices and energy storage devices and methods for the manufacture of such devices. The devices include a support member having an array of pore channels having a small average pore channel diameter and having a pore channel length. Material layers that may include energy conversion materials and conductive materials are coaxially disposed within the pore channels to form material rods having a relatively small cross-section and a relatively long length. By varying the structure of the materials in the pore channels, various energy devices can be fabricated, such as photovoltaic (PV) devices, radiation detectors, capacitors, batteries and the like.

Magnetic Fusion Energy Program of India

International Nuclear Information System (INIS)

Sen, Abhijit

2013-01-01

The magnetic fusion energy program of India started in the early eighties with the construction of an indigenous tokamak device ADITYA at the Institute for Plasma Research in Gandhinagar. The initial thrust was on fundamental studies related to plasma instabilities and turbulence phenomena but there was also a significant emphasis on technology development in the areas of magnetics, high vacuum, radio-frequency heating and neutral beam technology. The program took a major leap forward in the late nineties with the decision to build a state-of-the-art superconducting tokamak (SST-1) that catapulted India into the mainstream of the international tokamak research effort. The SST experience and the associated technological and human resource development has now earned the country a place in the ITER collaboration as an equal partner with other major nations. Keeping in mind the rapidly growing and enormous energy needs of the future the program has also identified and launched key development projects that can lead us to a DEMO reactor and eventually a Fusion Power Plant in a systematic manner. I will give a brief overview of the early origins, the present status and some of the highlights of the future road map of the Indian Fusion Program. (author)

Design and evaluation of a laser fusion energy station for industrial applications

International Nuclear Information System (INIS)

Kok, K.D.; Bates, F.J.; Denning, R.S.; Triplett, M.B.; Waddell, J.D.

1978-01-01

The identification and development of long-term energy options is important in the continued growth of industry in the United States. Fusion and particularly laser fusion is one of the possible options. This paper applies the criteria used by industry in the selection of an energy source to the first of a series of conceptual designs for a laser fusion energy station. Several conclusions are presented including the constraints placed on the design by the criteria

Real options valuation of fusion energy R and D programme

International Nuclear Information System (INIS)

Bednyagin, Denis; Gnansounou, Edgard

2011-01-01

This paper aims to perform a real options valuation of fusion energy R and D programme. Strategic value of thermonuclear fusion technology is estimated here based on the expected cash flows from construction and operation of fusion power plants and the real options value arising due to managerial flexibility and the underlying uncertainty. First, a basic investment option model of Black-Scholes type is being considered. Then, a fuzzy compound real R and D option model is elaborated, which reflects in a better way the multi-stage nature of the programme and takes into account the imprecision of information as one of the components of the overall programme uncertainty. Two different strategies are compared: 'Baseline' corresponding to a relatively moderate pace of fusion research, development, demonstration and deployment activities vs. 'Accelerated' strategy, which assumes a rapid demonstration and massive deployment of fusion. The conclusions are drawn from the model calculations regarding the strategic value of fusion energy R and D and the advantages of accelerated development path. - Research highlights: → Real options analysis of fusion R and D, demonstration and deployment (RDDD) programme. → ENPV of fusion RDDD programme is calculated using stochastic probabilistic simulation. → Fusion RDDD programme exhibits substantial positive real options value: Euro 245 billion. → Fuzzy compound real option valuation method provides more robust results.

Dynamics of anion-molecule reactions at low energy

International Nuclear Information System (INIS)

Mikosch, J.

2007-11-01

Anion-molecule reactions must find their way through deeply bound entrance and exit channel complexes separated by a central barrier. This results in low reaction rates and rich dynamics since direct pathways compete with the formation of transient intermediates. In this thesis we examine the probability of proton transfer to a small anion and transient lifetimes of a thermoneutral bimolecular nucleophilic substitution (S N 2) reaction at well defined variable temperature down to 8 Kelvin in a multipole trap. The observed strong inverse temperature dependence is attributed to the deficit of available quantum states in the entrance channel at decreasing temperature. Furthermore we investigate scattering dynamics of S N 2 reactions at defined relative energy between 0.4 and 10 eV by crossed beam slice imaging. A weakly exothermic reaction with high central barrier proceeds via an indirect, complex-mediated mechanism at low relative energies featuring high internal product excitation in excellent quantitative agreement with a statistical model. In contrast, direct backward scattering prevails for higher energies with product velocities close to the kinematical cutoff. For a strongly exothermic reaction, competing S N 2-, dihalide- and proton transfer-channels are explored which proceed by complex mediation for low energy and various rebound-, grazing- and collision induced bond rupture-mechanisms at higher energy. From our data and a collaboration with theory we identify a new indirect roundabout S N 2 mechanism involving CH 3 -rotation. (orig.)

Dynamics of anion-molecule reactions at low energy

Energy Technology Data Exchange (ETDEWEB)

Mikosch, J.

2007-11-15

Anion-molecule reactions must find their way through deeply bound entrance and exit channel complexes separated by a central barrier. This results in low reaction rates and rich dynamics since direct pathways compete with the formation of transient intermediates. In this thesis we examine the probability of proton transfer to a small anion and transient lifetimes of a thermoneutral bimolecular nucleophilic substitution (S{sub N}2) reaction at well defined variable temperature down to 8 Kelvin in a multipole trap. The observed strong inverse temperature dependence is attributed to the deficit of available quantum states in the entrance channel at decreasing temperature. Furthermore we investigate scattering dynamics of S{sub N}2 reactions at defined relative energy between 0.4 and 10 eV by crossed beam slice imaging. A weakly exothermic reaction with high central barrier proceeds via an indirect, complex-mediated mechanism at low relative energies featuring high internal product excitation in excellent quantitative agreement with a statistical model. In contrast, direct backward scattering prevails for higher energies with product velocities close to the kinematical cutoff. For a strongly exothermic reaction, competing S{sub N}2-, dihalide- and proton transfer-channels are explored which proceed by complex mediation for low energy and various rebound-, grazing- and collision induced bond rupture-mechanisms at higher energy. From our data and a collaboration with theory we identify a new indirect roundabout S{sub N}2 mechanism involving CH{sub 3}-rotation. (orig.)

Reactions with Weakly Bound Nuclei, at near Barrier Energies, and the Breakup and Transfer Influences on the Fusion and Elastic Scattering

International Nuclear Information System (INIS)

Gomes, P. R. S.; Lubian, J.; Mendes-Junior, D. R.; Faria, P. N. de; Linares, R.; Sigaud, L.; Rangel, J.; Ferreira, J. L.; Paes, B.; Cardozo, E. N.; Cortes, M. R.; Canto, L. F.; Ermamatov, M. J.; Otomar, D. R.; Ferioli, E.; Lotti, P.; Hussein, M. S.

2016-01-01

We present a brief review of the reaction mechanisms involved in collisions of weakly bound projectiles with tightly bound targets, at near-barrier energies. We discuss systematic behaviors of the data, with emphasis in fusion, breakup, nucleon transfer and elastic scattering. The dependence of the breakup cross section on the charge and mass of the target is discussed, and the influence of the breakup channel on complete fusion is investigated. For this purpose, we compare reduced fusion cross sections with a benchmark universal curve. The behaviors observed in the comparisons are explained in terms of polarization potentials and of nucleon transfer followed by breakup. The influence of the breakup process on elastic scattering is also discussed. Some apparent contradictions between results of different authors are explained and some perspectives of the field are presented. (author)

Effects of fusion relevant transient energetic radiation, plasma and thermal load on PLANSEE double forged tungsten samples in a low-energy plasma focus device

Science.gov (United States)

Javadi, S.; Ouyang, B.; Zhang, Z.; Ghoranneviss, M.; Salar Elahi, A.; Rawat, R. S.

2018-06-01

Tungsten is the leading candidate for plasma facing component (PFC) material for thermonuclear fusion reactors and various efforts are ongoing to evaluate its performance or response to intense fusion relevant radiation, plasma and thermal loads. This paper investigates the effects of hot dense decaying pinch plasma, highly energetic deuterium ions and fusion neutrons generated in a low-energy (3.0 kJ) plasma focus device on the structure, morphology and hardness of the PLANSEE double forged tungsten (W) samples surfaces. The tungsten samples were provided by Forschungszentrum Juelich (FZJ), Germany via International Atomic Energy Agency, Vienna, Austria. Tungsten samples were irradiated using different number of plasma focus (PF) shots (1, 5 and 10) at a fixed axial distance of 5 cm from the anode top and also at various distances from the top of the anode (5, 7, 9 and 11 cm) using fixed number (5) of plasma focus shots. The virgin tungsten sample had bcc structure (α-W phase). After PF irradiation, the XRD analysis showed (i) the presence of low intensity new diffraction peak corresponding to β-W phase at (211) crystalline plane indicating the partial structural phase transition in some of the samples, (ii) partial amorphization, and (iii) vacancy defects formation and compressive stress in irradiated tungsten samples. Field emission scanning electron microscopy showed the distinctive changes to non-uniform surface with nanometer sized particles and particle agglomerates along with large surface cracks at higher number of irradiation shots. X-ray photoelectron spectroscopy analysis demonstrated the reduction in relative tungsten oxide content and the increase in metallic tungsten after irradiation. Hardness of irradiated samples initially increased for one shot exposure due to reduction in tungsten oxide phase, but then decreased with increasing number of shots due to increasing concentration of defects. It is demonstrated that the plasma focus device provides

Report of the Fusion Energy Sciences Advisory Committee. Panel on Integrated Simulation and Optimization of Magnetic Fusion Systems

International Nuclear Information System (INIS)

Dahlburg, Jill; Corones, James; Batchelor, Donald; Bramley, Randall; Greenwald, Martin; Jardin, Stephen; Krasheninnikov, Sergei; Laub, Alan; Leboeuf, Jean-Noel; Lindl, John; Lokke, William; Rosenbluth, Marshall; Ross, David; Schnack, Dalton

2002-01-01

Fusion is potentially an inexhaustible energy source whose exploitation requires a basic understanding of high-temperature plasmas. The development of a science-based predictive capability for fusion-relevant plasmas is a challenge central to fusion energy science, in which numerical modeling has played a vital role for more than four decades. A combination of the very wide range in temporal and spatial scales, extreme anisotropy, the importance of geometric detail, and the requirement of causality which makes it impossible to parallelize over time, makes this problem one of the most challenging in computational physics. Sophisticated computational models are under development for many individual features of magnetically confined plasmas and increases in the scope and reliability of feasible simulations have been enabled by increased scientific understanding and improvements in computer technology. However, full predictive modeling of fusion plasmas will require qualitative improvements and innovations to enable cross coupling of a wider variety of physical processes and to allow solution over a larger range of space and time scales. The exponential growth of computer speed, coupled with the high cost of large-scale experimental facilities, makes an integrated fusion simulation initiative a timely and cost-effective opportunity. Worldwide progress in laboratory fusion experiments provides the basis for a recent FESAC recommendation to proceed with a burning plasma experiment (see FESAC Review of Burning Plasma Physics Report, September 2001). Such an experiment, at the frontier of the physics of complex systems, would be a huge step in establishing the potential of magnetic fusion energy to contribute to the world's energy security. An integrated simulation capability would dramatically enhance the utilization of such a facility and lead to optimization of toroidal fusion plasmas in general. This science-based predictive capability, which was cited in the

Report of the Fusion Energy Sciences Advisory Committee. Panel on Integrated Simulation and Optimization of Magnetic Fusion Systems

Energy Technology Data Exchange (ETDEWEB)

Dahlburg, Jill [General Atomics, San Diego, CA (United States); Corones, James [Krell Inst., Ames, IA (United States); Batchelor, Donald [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bramley, Randall [Indiana Univ., Bloomington, IN (United States); Greenwald, Martin [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Jardin, Stephen [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Krasheninnikov, Sergei [Univ. of California, San Diego, CA (United States); Laub, Alan [Univ. of California, Davis, CA (United States); Leboeuf, Jean-Noel [Univ. of California, Los Angeles, CA (United States); Lindl, John [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lokke, William [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rosenbluth, Marshall [Univ. of California, San Diego, CA (United States); Ross, David [Univ. of Texas, Austin, TX (United States); Schnack, Dalton [Science Applications International Corporation, Oak Ridge, TN (United States)

2002-11-01

Fusion is potentially an inexhaustible energy source whose exploitation requires a basic understanding of high-temperature plasmas. The development of a science-based predictive capability for fusion-relevant plasmas is a challenge central to fusion energy science, in which numerical modeling has played a vital role for more than four decades. A combination of the very wide range in temporal and spatial scales, extreme anisotropy, the importance of geometric detail, and the requirement of causality which makes it impossible to parallelize over time, makes this problem one of the most challenging in computational physics. Sophisticated computational models are under development for many individual features of magnetically confined plasmas and increases in the scope and reliability of feasible simulations have been enabled by increased scientific understanding and improvements in computer technology. However, full predictive modeling of fusion plasmas will require qualitative improvements and innovations to enable cross coupling of a wider variety of physical processes and to allow solution over a larger range of space and time scales. The exponential growth of computer speed, coupled with the high cost of large-scale experimental facilities, makes an integrated fusion simulation initiative a timely and cost-effective opportunity. Worldwide progress in laboratory fusion experiments provides the basis for a recent FESAC recommendation to proceed with a burning plasma experiment (see FESAC Review of Burning Plasma Physics Report, September 2001). Such an experiment, at the frontier of the physics of complex systems, would be a huge step in establishing the potential of magnetic fusion energy to contribute to the world’s energy security. An integrated simulation capability would dramatically enhance the utilization of such a facility and lead to optimization of toroidal fusion plasmas in general. This science-based predictive capability, which was cited in the FESAC

Heavy cluster in cold nuclear rearrangements in fusion and fission

International Nuclear Information System (INIS)

Armbruster, P.

1997-01-01

The experimental evidence for the appearance of cluster aspects in the dynamics of large rearrangements processes, as fusion and fission, is presented. Clusters in the sense as used in the following are strongly bound, doubly magic neutron rich nuclei as 48 Ca 28 , 78 Ni 50 , 132 Sn 82 , and 208 Pb 126 , the spherical nuclei Z=114 - 126 and N=184, and nuclei with closed shells N=28, 50, 82, and 126, and Z=28, 50, and 82. As with increasing nucleon numbers, the absolute shell corrections to the binding energies increase, the strongest effects are to be observed for the higher shells. The 132 cluster manifests itself in low energy fission (Faissner, H. and Wildermuth, K. Nucl. Phys., 58 (1964) 177). The 208 Pb cluster gave the new radioactivity (Rose, M.J. and Jones G.A., Nature, 307 (1984) 245) and the first superheavy elements (SHE) (Armbruster P., Ann. Rev. Nucl. Part. Sci., 35 (1985) 135-94; Munzenberg, G. Rep. Progr. Phys., 51 (1988) 57). The paper discuss experiments concerning the stability of clusters to intrinsic excitation energy in fusion and fission (Armbruster, P. Lect. Notes Phys., 158 (1982) 1). and the manifestation of clusters in the fusion entrance channel (Armbruster, P., J. Phys. Soc. Jpn., 58 (1989) 232). The importance of compactness of the clustering system seems to be equally decisive in fission and fusion. Finally, it s covered the importance of clusters for the production of SHEs)

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)

Accelerators for heavy ion inertial fusion: Progress and plans

International Nuclear Information System (INIS)

Bangerter, R.O.; Friedman, A.; Herrmannsfeldt, W.B.

1994-08-01

The Heavy Ion Inertial Fusion Program is the principal part of the Inertial Fusion Energy Program in the Office of Fusion Energy of the U.S. Department of Energy. The emphasis of the Heavy Ion Program is the development of accelerators for fusion power production. Target physics research and some elements of fusion chamber development are supported in the much larger Inertial Confinement Fusion Program, a dual purpose (defense and energy) program in the Defense Programs part of the Department of Energy. The accelerator research program will establish feasibility through a sequence of scaled experiments that will demonstrate key physics and engineering issues at low cost compared to other fusion programs. This paper discusses progress in the accelerator program and outlines how the planned research will address the key economic issues of inertial fusion energy

Disentangling complete and incomplete fusion for 9Be+187Re system at near barrier energies

International Nuclear Information System (INIS)

Kharab, Rajesh; Chahal, Rajiv; Rajiv Kumar

2015-01-01

The breakup of projectile before fusion leads to some unusual fusion mechanisms like incomplete fusion (ICF) and sequential complete fusion (SCF). Experimentally, it is not possible to separate SCF events from direct complete fusion (DCF). However, the complete fusion and incomplete fusion can be measured separately. Theoretically it is very difficult to calculate the complete and incomplete fusion cross section separately using different models. Very recently A. Diaz-Torres has developed a computer code platypus based on classical dynamical model wherein the complete and incomplete fusion cross sections are calculated separately. But this model is found to work very well at energies above the barrier energy. Here we have attempted to extrapolate the results of the code platypus by using simple Wong's formula in conjunction with the energy dependent Woods-Saxon potential (EDWSP) in the below barrier energy region

Many-body treatment of subbarrier fusion reactions

Energy Technology Data Exchange (ETDEWEB)

Iwamoto, Akira; Kondratyev, V. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Bonasera, A.

1998-07-01

The subbarrier fusion of heavy-ions at energies around the Coulomb barrier is studied by using semiclassical mean-field theory. The paths connecting entrance and exit subbarrier fusion reaction channels are found by incorporating the Wick transformation into the mean-field kinetic equation. The polarization and deformation of nuclei is shown to lower the barrier height. It is demonstrated that preequilibrium nucleon exchange in classically forbidden region gives rise to the nonlocal effects lowering the effective barrier further at small relative distance. (author)

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

Intelligible seminar on fusion reactors. (12) Next step toward the realization of fusion reactors. Future vision of fusion energy research and development

International Nuclear Information System (INIS)

Okano, Kunihiko; Kurihara, Kenichi; Tobita, Kenji

2006-01-01

In the last session of this seminar the progress of research and development for the realization of fusion reactors and future vision of fusion energy research and development are summarized. The some problems to be solved when the commercial fusion reactors would be realized, (1) production of deuterium as the fuel, (2) why need the thermonuclear reactors, (3) environmental problems, and (4) ITER project, are described. (H. Mase)

Status of tritium technology development for magnetic-fusion energy

International Nuclear Information System (INIS)

Anderson, J.L.

1983-01-01

The development of tritium technology for the magnetic fusion energy program has progressed at a rapid rate over the past two years. The focal points for this development in the United States have been the Tritium Systems Test Assembly at Los Alamos and the FED/INTOR studies supported by the Fusion Engineering Design Center at Oak Ridge. In Canada the Canadian Fusion Fuel Technology Project has been initiated and promises to make significant contributions to the tritium technology program in the next few years. The Japanese government has now approved funding for the Tritium Processing Laboratory at the Japan Atomic Energy Research Institute's Tokai Research Establishment. Construction on this new facility is scheduled to begin in April 1983. This facility will be the center for fusion tritium technology development in Japan. The European Community is currently working on the design of the tritium facility for the Joint European Torus. There is considerable interaction between all of these programs, thus accelerating the overall development of this crucial technology

Observation of strong reflection of electron waves exiting a ballistic channel at low energy

Energy Technology Data Exchange (ETDEWEB)

Vaz, Canute I.; Campbell, Jason P.; Ryan, Jason T.; Gundlach, David; Cheung, Kin. P., E-mail: Kin.Cheung@NIST.gov [National Institute of Standards and Technology, Gaithersburg, MD 20899-8120 (United States); Liu, Changze [National Institute of Standards and Technology, Gaithersburg, MD 20899-8120 (United States); Institute of Microelectronics, Peking University, Beijing 100871 (China); Southwick, Richard G. [National Institute of Standards and Technology, Gaithersburg, MD 20899-8120 (United States); IBM Research, Albany, NY 12205 (United States); Oates, Anthony S. [Taiwan Semiconductor Manufacturing Corporation, Hsinchu 30844, Taiwan (China); Huang, Ru [Institute of Microelectronics, Peking University, Beijing 100871 (China)

2016-06-15

Wave scattering by a potential step is a ubiquitous concept. Thus, it is surprising that theoretical treatments of ballistic transport in nanoscale devices, from quantum point contacts to ballistic transistors, assume no reflection even when the potential step is encountered upon exiting the device. Experiments so far seem to support this even if it is not clear why. Here we report clear evidence of coherent reflection when electron wave exits the channel of a nanoscale transistor and when the electron energy is low. The observed behavior is well described by a simple rectangular potential barrier model which the Schrodinger’s equation can be solved exactly. We can explain why reflection is not observed in most situations but cannot be ignored in some important situations. Our experiment also represents a direct measurement of electron injection velocity - a critical quantity in nanoscale transistors that is widely considered not measurable.

Isotopic effects in sub-barrier fusion of Si + Si systems

Science.gov (United States)

Colucci, G.; Montagnoli, G.; Stefanini, A. M.; Esbensen, H.; Bourgin, D.; Čolović, P.; Corradi, L.; Faggian, M.; Fioretto, E.; Galtarossa, F.; Goasduff, A.; Grebosz, J.; Haas, F.; Mazzocco, M.; Scarlassara, F.; Stefanini, C.; Strano, E.; Szilner, S.; Urbani, M.; Zhang, G. L.

2018-04-01

Background: Recent measurements of fusion cross sections for the 28Si+28Si system revealed a rather unsystematic behavior; i.e., they drop faster near the barrier than at lower energies. This was tentatively attributed to the large oblate deformation of 28Si because coupled-channels (CC) calculations largely underestimate the 28Si+28Si cross sections at low energies, unless a weak imaginary potential is applied, probably simulating the deformation. 30Si has no permanent deformation and its low-energy excitations are of a vibrational nature. Previous measurements of this system reached only 4 mb, which is not sufficient to obtain information on effects that should show up at lower energies. Purpose: The aim of the present experiment was twofold: (i) to clarify the underlying fusion dynamics by measuring the symmetric case 30Si+30Si in an energy range from around the Coulomb barrier to deep sub-barrier energies, and (ii) to compare the results with the behavior of 28Si+28Si involving two deformed nuclei. Methods: 30Si beams from the XTU tandem accelerator of the Laboratori Nazionali di Legnaro of the Istituto Nazionale di Fisica Nucleare were used, bombarding thin metallic 30Si targets (50 μ g /cm2) enriched to 99.64 % in mass 30. An electrostatic beam deflector allowed the detection of fusion evaporation residues (ERs) at very forward angles, and angular distributions of ERs were measured. Results: The excitation function of 30Si+30Si was measured down to the level of a few microbarns. It has a regular shape, at variance with the unusual trend of 28Si+28Si . The extracted logarithmic derivative does not reach the LCS limit at low energies, so that no maximum of the S factor shows up. CC calculations were performed including the low-lying 2+ and 3- excitations. Conclusions: Using a Woods-Saxon potential the experimental cross sections at low energies are overpredicted, and this is a clear sign of hindrance, while the calculations performed with a M3Y + repulsion

L-Type Voltage-Gated Ca2+ Channels Regulate Synaptic-Activity-Triggered Recycling Endosome Fusion in Neuronal Dendrites

Directory of Open Access Journals (Sweden)

Brian G. Hiester

2017-11-01

Full Text Available The repertoire and abundance of proteins displayed on the surface of neuronal dendrites are tuned by regulated fusion of recycling endosomes (REs with the dendritic plasma membrane. While this process is critical for neuronal function and plasticity, how synaptic activity drives RE fusion remains unexplored. We demonstrate a multistep fusion mechanism that requires Ca2+ from distinct sources. NMDA receptor Ca2+ initiates RE fusion with the plasma membrane, while L-type voltage-gated Ca2+ channels (L-VGCCs regulate whether fused REs collapse into the membrane or reform without transferring their cargo to the cell surface. Accordingly, NMDA receptor activation triggered AMPA-type glutamate receptor trafficking to the dendritic surface in an L-VGCC-dependent manner. Conversely, potentiating L-VGCCs enhanced AMPA receptor surface expression only when NMDA receptors were also active. Thus L-VGCCs play a role in tuning activity-triggered surface expression of key synaptic proteins by gating the mode of RE fusion.