Thermonuclear research development

Energy Technology Data Exchange (ETDEWEB)

Velikhov, E

1977-04-01

Tokamak 10, the world's largest thermonuclear facility was commissioned in 1975. Soviet scientists thus achieved enormous success in producing high-temperature plasma and constructing a thermonuclear fusion source. The problems which remain to be solved include finding a method of regenerating the deuterium-tritium fuel mixture and a method of purifying the reacting high-temperature plasma of heavy elements. The project is designed for a more powerful facility, namely the Tokamak 20 whose toroidal chamber will accommodate a current of 5 to 6 MA and whose plasma volume will be 400 m/sup 3/.

First implosion experiments with cryogenic thermonuclear fuel on the National Ignition Facility

International Nuclear Information System (INIS)

Glenzer, Siegfried H; Spears, Brian K; Edwards, M John; Berger, Richard L; Bleuel, Darren L; Bradley, David K; Caggiano, Joseph A; Callahan, Debra A; Castro, Carlos; Choate, Christine; Clark, Daniel S; Cerjan, Charles J; Collins, Gilbert W; Dewald, Eduard L; Di Nicola, Jean-Michel G; Di Nicola, Pascale; Divol, Laurent; Dixit, Shamasundar N; Alger, Ethan T; Casey, Daniel T

2012-01-01

Non-burning thermonuclear fuel implosion experiments have been fielded on the National Ignition Facility to assess progress toward ignition by indirect drive inertial confinement fusion. These experiments use cryogenic fuel ice layers, consisting of mixtures of tritium and deuterium with large amounts of hydrogen to control the neutron yield and to allow fielding of an extensive suite of optical, x-ray and nuclear diagnostics. The thermonuclear fuel layer is contained in a spherical plastic capsule that is fielded in the center of a cylindrical gold hohlraum. Heating the hohlraum with 1.3 MJ of energy delivered by 192 laser beams produces a soft x-ray drive spectrum with a radiation temperature of 300 eV. The radiation field produces an ablation pressure of 100 Mbar which compresses the capsule to a spherical dense fuel shell that contains a hot plasma core 80 µm in diameter. The implosion core is observed with x-ray imaging diagnostics that provide size, shape, the absolute x-ray emission along with bangtime and hot plasma lifetime. Nuclear measurements provide the 14.1 MeV neutron yield from fusion of deuterium and tritium nuclei along with down-scattered neutrons at energies of 10–12 MeV due to energy loss by scattering in the dense fuel that surrounds the central hot-spot plasma. Neutron time-of-flight spectra allow the inference of the ion temperature while gamma-ray measurements provide the duration of nuclear activity. The fusion yield from deuterium–tritium reactions scales with ion temperature, which is in agreement with modeling over more than one order of magnitude to a neutron yield in excess of 10 14 neutrons, indicating large confinement parameters on these first experiments. (paper)

Thermonuclear plasma physic: inertial confinement fusion

International Nuclear Information System (INIS)

Bayer, Ch.; Juraszek, D.

2001-01-01

Inertial Confinement Fusion (ICF) is an approach to thermonuclear fusion in which the fuel contained in a spherical capsule is strongly compressed and heated to achieve ignition and burn. The released thermonuclear energy can be much higher than the driver energy, making energetic applications attractive. Many complex physical phenomena are involved by the compression process, but it is possible to use simple analytical models to analyze the main critical points. We first determine the conditions to obtain fuel ignition. High thermonuclear gains are achieved if only a small fraction of the fuel called hot spot is used to trigger burn in the main fuel compressed on a low isentrope. A simple hot spot model will be described. The high pressure needed to drive the capsule compression are obtained by the ablation process. A simple Rocket model describe the main features of the implosion phase. Several parameters have to be controlled during the compression: irradiation symmetry, hydrodynamical stability and when the driver is a laser, the problems arising from interaction of the EM wave with the plasma. Two different schemes are examined: Indirect Drive which uses X-ray generated in a cavity to drive the implosion and the Fast Ignitor concept using a ultra intense laser beam to create the hot spot. At the end we present the Laser Megajoule (LMJ) project. LMJ is scaled to a thermonuclear gain of the order of ten. (authors)

Effect of spatial nonuniformity of heating on compression and burning of a thermonuclear target under direct multibeam irradiation by a megajoule laser pulse

Energy Technology Data Exchange (ETDEWEB)

Bel’kov, S. A.; Bondarenko, S. V. [Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (Russian Federation); Vergunova, G. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Garanin, S. G. [Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (Russian Federation); Gus’kov, S. Yu.; Demchenko, N. N.; Doskoch, I. Ya. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Zmitrenko, N. V. [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Kuchugov, P. A., E-mail: pkuchugov@gmail.com; Rozanov, V. B.; Stepanov, R. V.; Yakhin, R. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2017-02-15

Direct-drive fusion targets are considered at present as an alternative to targets of indirect compression at a laser energy level of about 2 MJ. In this approach, the symmetry of compression and ignition of thermonuclear fuel play the major role. We report on the results of theoretical investigation of compression and burning of spherical direct-drive targets in the conditions of spatial nonuniformity of heating associated with a shift of the target from the beam center of focusing and possible laser radiation energy disbalance in the beams. The investigation involves numerous calculations based on a complex of 1D and 2D codes RAPID, SEND (for determining the target illumination and the dynamics of absorption), DIANA, and NUT (1D and multidimensional hydrodynamics of compression and burning of targets). The target under investigation had the form of a two-layer shell (ablator made of inertial material CH and DT ice) filled with DT gas. We have determined the range of admissible variation of compression and combustion parameters of the target depending on the variation of the spatial nonuniformity of its heating by a multibeam laser system. It has been shown that low-mode (long-wavelength) perturbations deteriorate the characteristics of the central region due to less effective conversion of the kinetic energy of the target shell into the internal energy of the center. Local initiation of burning is also observed in off-center regions of the target in the case of substantial asymmetry of irradiation. In this case, burning is not spread over the entire volume of the DT fuel as a rule, which considerably reduces the thermonuclear yield as compared to that in the case of spherical symmetry and central ignition.

On the energy gain enhancement of DT+D3He fuel configuration in nuclear fusion reactor driven by heavy ion beams

Directory of Open Access Journals (Sweden)

S Khoshbinfar

2016-09-01

Full Text Available It is expected that advanced fuels be employed in the second generation of nuclear fusion reactors. Theoretical calculations show that in such a fuel, a high plasma temperature about 100 keV is a requisite for reaction rate improvement of nuclear fusion. However, creating such a temporal condition requires a more powerful driver than we have today. Here, introducing an optimal fuel configuration consisting of DT and D-3He layers, suitable for inertial fusion reactors and driven by heavy ion beams, the optimal energy gain conditions have been simulated and derived for 1.3 MJ system. It was found that, in this new fuel configuration, the ideal energy gain, is 22 percent more comparing with energy gain in corresponding single DT fuel layer. Moreover, the inner DT fuel layer contributed as an ignition trigger, while the outer D3He fuel acts as particle and radiation shielding as well as fuel layer.

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

Investigation of the stationary-thermonuclear-reaction realization possibility in a tokamak device

International Nuclear Information System (INIS)

Kolesnichenko, Ya.I.; Reznik, S.N.; Fursa, A.D.

1976-01-01

The stationary (quasistationary) selfsustaining thermonuclear D-T reaction is shown to be possible in a toroidal device such as 'Tokamak' with large enough plasma radius. The stationary temperature of the plasma can be quite high. Thus when the transport processes are assumed to be neoclassical the temperature of the central part of a plasma colomn of radius approximately 10-200 cm in the stationary state is 70 keV.The stationary temperature distribution is reached spontaneously as a result of the thermal instability development if plasma is preheated to 10 keV. The stationary thermonuclear burning is also possible at lower temperatures if plasma energy balance is controlled

Cryogenic implications for DT

International Nuclear Information System (INIS)

Souers, P.C.

1977-10-01

Cryogenic hydrogen data is being compiled for magnetic fusion engineering. Many physical properties of DT can be extrapolated from H 2 and D 2 values. The phase diagram properties of the D 2 -DT-T 2 mixture are being measured. Three properties which will be greatly affected by tritium should be measured. In order of their perceived importance, they are: (1) solid thermal conductivity, (2) solid mechanical strength, and (3) gaseous electrical conductivity. The most apparent need for DT data is in Tokomak fuel pellet injection. Cryopumping and distillation applications are also considered

Laser fusion experiments at 2 TW. [Argus system; implosion of D-T filled glass microspheres

Energy Technology Data Exchange (ETDEWEB)

Storm, E.K.; Ahlstrom, H.G.; Boyle, M.J.

1976-10-01

The Lawrence Livermore Laboratory Solid State Laser System, Arqus, has successfully performed laser implosion experiments at power levels exceeding 2 TW. D-T filled glass microspheres have been imploded to yield thermonuclear reaction products in excess of 5 x 10/sup 8/ per event. Neutron and ..cap alpha.. time-of-flight measurements indicate that D-T ion temperatures of approximately 5-6 keV and a density confinement time product (n tau) of approximately 1 x 10/sup 12/ were obtained in these experiments. Typically two 40J, 40 psec pulses of 1.06 ..mu..m light were focused on targets using 20 cm aperture f/1 lenses, producing intensities at the target in excess of 10/sup 16/ W/cm/sup 2/. An extensive array of diagnostics routinely monitored the laser performance and the laser target interaction process. Measurements of absorption and asymmetry in both the scattered light distribution and the ion blow off is evidence for non-classical absorption mechanisms and density scale heights of the order of 2 ..mu..m or less. The symmetry of the thermonuclear burn region is investigated by monitoring the ..cap alpha..-particle flux in several directions, and an experiment to image the thermonuclear burn region is in process. These experiments significantly extend our data base and our understanding of laser induced thermonuclear implosions and the basic laser plasma interaction physics from the 0.4 to 0.7 TW level of previous experiments.

A pellet model of DT ignitor and DD fuel for an ICF reactor without tritium breeding blanket

International Nuclear Information System (INIS)

Ido, Shunji; Tazima, Teruhiko.

1983-01-01

A pellet concept of a DT ignitor and DD fuel for an ICF reactor without a tritium breeding blanket is analytically examined under the condition that T is bred through the DD reactions. There is the additional restriction that the tritium breeding ratio in a pellet is unity, including the in situ DT burn in the DD region. Model calculations show that sufficiently high pellet gain can be obtained in a DT-DD pellet, when fuel rhoR increases to --40 g/cm 2 and the fraction of energy released in the DD region becomes dominant. One-dimensional neutronics calculations carried out for a reference pellet model with rhoR --40 g/cm 2 show that the neutron heating in the compressed pellet model is evident and the total energy of the neutrons escaping from the pellet is reduced from --2000 MJ to 330 MJ for a microexplosion of --3000 MJ. (author)

Fissile fuel production and usage of thermal reactor waste fueled with UO2 by means of hybrid reactor system

International Nuclear Information System (INIS)

Ipek, O.

1997-01-01

The use of Fast Breeder Reactors to produce fissile fuel from nuclear waste and the operation of these reactors with a new neutron source are becoming today' topic. In the thermonuclear reactors, it is possible to use 2.45-14.1 MeV - neutrons which can be obtained by D-T, D-D Semicatalyzed (D-D) and other fusion reactions. To be able to do these, Hybrid Reactor System, which still has experimental and theoretical studies, have to be taken into consideration.In this study, neutronic analysis of hybrid blanket with grafit reflector, is performed. D-T driven fusion reaction is surrounded by UO 2 fuel layer and the production of ''2''3''9Pu fissile fuel from waste ''2''3''8U is analyzed. It is also compared to the other possible fusion reactions. The results show that 815.8 kg/year ''2''3''8Pu with D-T reaction and 1431.6 kg/year ''2''3''8Pu with semicatalyzed (D-D) reaction can be produced for 1000 MW fusion power. This means production of 2.8/ year and 4.94/ year LWR respectively. In addition, 1000 MW fusion flower is is multiplicated to 3415 MW and 4274 MW for D-T and semicatalyzed (D-D) reactions respectively. The system works subcritical and these values are 0.4115 and 0.312 in order. The calculations, ANISN-ORNL code, S 16 -P 3 approach and DLC36 data library are used

Control method for thermonuclear plasma

International Nuclear Information System (INIS)

Azuma, Kingo; Oda, Yasushi.

1997-01-01

CT (Compact Troid) is a doughnut-like shaped plasmas having a toroidal current and a poloidal current at the inside and forming a poloidal magnetic fluxes and toroidal magnetic flux. The structure of the CT is collapsed at a time of stationary state, accordingly, when it is injected to thermonuclear plasmas, particles can be supplied locally, and the state of the plasmas to be supplied can be changed by changing the direction of the injection. If a CT which is reverse to the poloidal magnetic fields is injected, plasmas with excessive ions can be supplied locally thereby enabling to form magnetic field in the thermonuclear plasmas. If the magnetic fields are formed in the vicinity of the surface of the thermonuclear plasmas, fast ions which have come over the magnetic field structure can be returned to the central portion of the plasmas. Then, confining performance of thermonuclear plasmas can be greatly improved, the efficiency for fuel supply can be increased, and energy required for ignition can be suppressed. (N.H.)

The Tokamak Fusion Test Reactor D-T modifications and operations

International Nuclear Information System (INIS)

1992-01-01

This Environmental Assessment (EA) was prepared in accordance with the National Environmental Policy Act (NEPA) of 1969, as amended, in support of the Department of Energy's proposal for the Tokamak Fusion Test Reactor (TFTR) D-T program. The objective of the proposed D-T program is to take the initial step in studying the effects of alpha particle heating and transport in a magnetic fusion device. These studies would enable the successful completion of the original TFTR program objectives, and would support the research and development needs of the Burning Plasma Experiment, BPX (formerly the Compact Ignition Tokamak (CIT)) and International Thermonuclear Experimental Reactor (ITER) in the areas of alpha particle physics, tritium retention, alpha particle diagnostic development, and tritium handling

A method and apparatus for the manufacture of glass microspheres adapted to contain a thermonuclear fuel

International Nuclear Information System (INIS)

Budrick, R.G.; Nolen, R.L. Jr.; Solomon, D.E.; King, F.T.

1975-01-01

The invention relates to the manufacture of glass microspheres. It refers to a method according to which a sintered glass-powder, whose particles are calibrated, is introduced into a blow-pipe adapted to project said glass-powder particles into a heated flue, said sintered glass-powder containing a pore-forming agent adapted to expand the glass particles into microspheres which are collected in a chamber situated abode said flue. The method can be applied to the manufacture of microspheres adapted to contain a thermonuclear fuel [fr

Thermonuclear detonation

International Nuclear Information System (INIS)

Feoktistov, L.P.

1998-01-01

The characteristics of, and energy transfer mechanisms involved in, thermonuclear detonation are discussed. What makes the fundamental difference between thermonuclear and chemical detonation is that the former has a high specific energy release and can therefore be employed for preliminary compressing the thermonuclear mixture ahead of the burning wave. Consequently, with moderate (mega joule) initiation energies, a steady-state detonation laboratory experiment with unlimited energy multiplication becomes a possibility

Thermonuclear Runaway model

International Nuclear Information System (INIS)

Sparks, W.M.; Kutter, G.S.; Starrfield, S.; Truran, J.W.

1989-01-01

The nova outburst requires an energy source that is energetic enough to eject material and is able to recur. The Thermonuclear Runaway (TNR) model, coupled with the binary nature of nova systems satisfies these conditions. The white dwarf/red dwarf binary nature of novae was first recognized as a necessary conditions by Kraft. The small separation characteristic of novae systems allows the cool, red secondary to overflow is Roche lobe. In the absence of strong, funneling magnetic fields, the angular momentum of this material prevents it from falling directly onto the primary, and it first forms a disk around the white dwarf. This material is eventually accreted from the disk onto the white dwarf. As the thickness of this hydrogen-rich layer increases, the degenerate matter at the base reaches a temperature that is high enough to initiate thermonuclear fusion of hydrogen. Thermonuclear energy release increases the temperature which in turn increases the energy generation rate. Because the material is degenerate, the pressure does not increase with temperature, which normally allows a star to adjust itself to a steady nuclear burning rate. Thus the temperature and nuclear energy generation increase and a TNR results. When the temperature reaches the Fermi temperature, degeneracy is lifted and the rapid pressure increase causes material expansion. The hydrogen-rich material either is ejected or consumed by nuclear burning, and the white dwarf returns to its pre-outburst state. The external source of hydrogen fuel from the secondary allows the while process to repeat. 43 refs., 8 figs

Thermonuclear detonation

International Nuclear Information System (INIS)

Feoktistov, L P

1998-01-01

The characteristics of, and energy transfer mechanisms involved in, thermonuclear detonation are discussed. What makes the fundamental difference between thermonuclear and chemical detonation is that the former has a high specific energy release and can therefore be employed for preliminarily compressing the thermonuclear mixture ahead of the burning wave. Consequently, with moderate (megajoule) initiation energies, a steady-state detonation laboratory experiment with unlimited energy multiplication becomes a possibility. (from the history of physics)

The scaling of economic and performance parameters of DT and advanced fuel fusion reactors

International Nuclear Information System (INIS)

Roth, J.R.

1983-01-01

In this study, the plasma stability index beta and the fusion power density in the plasma were treated as independent variables to determine how they influenced three economic performance parameters of fusion reactors burning the DT and four advanced fusion fuel cycles. The economic/performance parameters included the total power produced per unit length of reactor; the mass per unit length, and the specific mass in kilograms/kilowatt. The scaling of these parameters with beta and fusion power density was examined for a common set of engineering assumptions on the allowable wall loading limits, the maximum magnetic field existing in the plasma, average blanket mass density, etc. It was found that the power per unit length decreased as the plasma power density and beta increased. This is a consequence of the fact that the first wall is a bottleneck in the energy flow from the plasma to the generating equipment, and the wall power flux will exceed wall loading limits if the plasma radius exceeds a critical value. If one wished to build an engineering test reactor which produced a burning plasma at the lowest possible initial cost, and without regard to whether such a reactor would ultimately produce the cheapest power, then one would minimize the mass per unit length. The mass per unit length decreases with increasing plasma power density and beta, with the DT reaction being the most expensive at a fixed plasma power density (because of its thicker blanket), and the least expensive at a fixed value of beta, at least up to values of beta of 50%. The specific mass, in kg/kw, which is a rough measure of the cost of the power generated by the reactor, shows an opposite trend. It increases with increasing plasma power density and beta. At a given plasma power density and low beta, the DT reaction gives the lowest specific mass, but at a fixed beta above 10%, the advanced fuel cycles have the lowest specific mass

The Influence of Stellar Spin on Ignition of Thermonuclear Runaways

Science.gov (United States)

Galloway, Duncan K.; in ’t Zand, Jean J. M.; Chenevez, Jérôme; Keek, Laurens; Sanchez-Fernandez, Celia; Worpel, Hauke; Lampe, Nathanael; Kuulkers, Erik; Watts, Anna; Ootes, Laura; The MINBAR collaboration

2018-04-01

Runaway thermonuclear burning of a layer of accumulated fuel on the surface of a compact star provides a brief but intense display of stellar nuclear processes. For neutron stars accreting from a binary companion, these events manifest as thermonuclear (type-I) X-ray bursts, and recur on typical timescales of hours to days. We measured the burst rate as a function of accretion rate, from seven neutron stars with known spin rates, using a burst sample accumulated over several decades. At the highest accretion rates, the burst rate is lower for faster spinning stars. The observations imply that fast (>400 Hz) rotation encourages stabilization of nuclear burning, suggesting a dynamical dependence of nuclear ignition on the spin rate. This dependence is unexpected, because faster rotation entails less shear between the surrounding accretion disk and the star. Large-scale circulation in the fuel layer, leading to enhanced mixing of the burst ashes into the fuel layer, may explain this behavior; further numerical simulations are required to confirm this.

Controlled thermonuclear fusion

International Nuclear Information System (INIS)

Rebut, P.H.

1992-01-01

The author gives a chronological account of the research about thermonuclear fusion and presents the principle of JET thermonuclear reactor based upon the magnetic confinement. The problems of heating and confining a thermonuclear plasma may be regarded as solved. They make possible the definition of the size and geometry needed to realize a next-step tokamak (ITER, NET projects)

Diagnosing ignition with DT reaction history

International Nuclear Information System (INIS)

Wilson, D. C.; Bradley, P. A.; Herrmann, H. W.; Cerjan, C. J.; Salmonson, J. D.; Spears, B. K.; Hatchet, S. P. II; Glebov, V. Yu.

2008-01-01

A full range DT reaction history of an ignition capsule, from 10 9 to 10 20 neutrons/ns, offers the opportunity to diagnose fuel conditions hundreds of picoseconds before and during burn. The burn history begins with a sharp rise when the first shock reaches the center of the capsule. The level of this jump reflects the combined shock strength and the adiabat of DT fuel. Changes to the four laser pulses driving the capsule implosion which are large enough to degrade the yield make measurable changes to the reaction history. Low mode asymmetries grow during convergence but change the reaction history during the final ∼100 ps. High mode asymmetry or turbulence mixing affects only the reaction history within ∼50 ps of peak burn rate. A capsule with a tritium fuel layer containing a small amount of deuterium (∼1%) creates a reaction history similar to the ignition capsule, but without the final ignition burn. A combination of gas Cerenkov detectors and the neutron temporal diagnostic could be capable of diagnosing the full history of ignition and tritium rich capsules.

Thermonuclear plasma physic: inertial confinement fusion; Physique des plasmas thermonucleaires: la fusion par confinement inertiel

Energy Technology Data Exchange (ETDEWEB)

Bayer, Ch.; Juraszek, D

2001-07-01

Inertial Confinement Fusion (ICF) is an approach to thermonuclear fusion in which the fuel contained in a spherical capsule is strongly compressed and heated to achieve ignition and burn. The released thermonuclear energy can be much higher than the driver energy, making energetic applications attractive. Many complex physical phenomena are involved by the compression process, but it is possible to use simple analytical models to analyze the main critical points. We first determine the conditions to obtain fuel ignition. High thermonuclear gains are achieved if only a small fraction of the fuel called hot spot is used to trigger burn in the main fuel compressed on a low isentrope. A simple hot spot model will be described. The high pressure needed to drive the capsule compression are obtained by the ablation process. A simple Rocket model describe the main features of the implosion phase. Several parameters have to be controlled during the compression: irradiation symmetry, hydrodynamical stability and when the driver is a laser, the problems arising from interaction of the EM wave with the plasma. Two different schemes are examined: Indirect Drive which uses X-ray generated in a cavity to drive the implosion and the Fast Ignitor concept using a ultra intense laser beam to create the hot spot. At the end we present the Laser Megajoule (LMJ) project. LMJ is scaled to a thermonuclear gain of the order of ten. (authors)

Advanced fuels for nuclear fusion reactors

International Nuclear Information System (INIS)

McNally, J.R. Jr.

1974-01-01

Should magnetic confinement of hot plasma prove satisfactory at high β (16 πnkT//sub B 2 / greater than 0.1), thermonuclear fusion fuels other than D.T may be contemplated for future fusion reactors. The prospect of the advanced fusion fuels D.D and 6 Li.D for fusion reactors is quite promising provided the system is large, well reflected and possesses a high β. The first generation reactions produce the very active, energy-rich fuels t and 3 He which exhibit a high burnup probability in very hot plasmas. Steady state burning of D.D can ensue in a 60 kG field, 5 m reactor for β approximately 0.2 and reflectivity R/sub mu/ = 0.9 provided the confinement time is about 38 sec. The feasibility of steady state burning of 6 Li.D has not yet been demonstrated but many important features of such systems still need to be incorporated in the reactivity code. In particular, there is a need for new and improved nuclear cross section data for over 80 reaction possibilities

Plasma barodiffusion in inertial-confinement-fusion implosions: application to observed yield anomalies in thermonuclear fuel mixtures.

Science.gov (United States)

Amendt, Peter; Landen, O L; Robey, H F; Li, C K; Petrasso, R D

2010-09-10

The observation of large, self-generated electric fields (≥10(9)  V/m) in imploding capsules using proton radiography has been reported [C. K. Li, Phys. Rev. Lett. 100, 225001 (2008)]. A model of pressure gradient-driven diffusion in a plasma with self-generated electric fields is developed and applied to reported neutron yield deficits for equimolar D3He [J. R. Rygg, Phys. Plasmas 13, 052702 (2006)] and (DT)3He [H. W. Herrmann, Phys. Plasmas 16, 056312 (2009)] fuel mixtures and Ar-doped deuterium fuels [J. D. Lindl, Phys. Plasmas 11, 339 (2004)]. The observed anomalies are explained as a mild loss of deuterium nuclei near capsule center arising from shock-driven diffusion in the high-field limit.

Thermonuclear reaction listing

International Nuclear Information System (INIS)

Fukai, Yuzo

1993-01-01

The following 10 elements, including T, are well known as nuclear fusion fuels: p, D, T, 3 He, 4 He, 6 Li, 7 Li, 9 Be, 10 B, 11 B, ( 12 C, 13 C), where 12 C and 13 C are considered only in the calculation of Q value. Accordingly the number of the thermonuclear reactions is 55, and 78, if including carbon elements. The reactions have some branches. For the branches having two and three reaction products, the reaction products, Q value and threshold energy are calculated by using a computer. We have investigated those of the branches having more than three products from the papers of Ajzenberg-Selove and so on. And also, by the same papers, we check whether the above mentioned branch has been observed or not. The results are as follows: (I) the number of reactions which have Q 0 branches only with γ ray production, and Q 0 and neutron production is 36(17), and (IV) that of reactions whose branch with Q > 0 does not produce neutrons is 9(3). The value in the parentheses shows the number of the case of the carbon elements. For 55 thermonuclear reactions induced by lighter nuclides than 11 B, the reaction products, the values of Q and threshold energy, and the papers with reaction cross section data are presented in the tables. (author)

On the Potential Role of Species Separation in DT Fuels on Implosion Performance

Science.gov (United States)

Amendt, Peter; Bellei, Claudio; Wilks, Scott; Haines, Malcolm; Casey, Dan; Li, C. K.; Petrasso, Richard

2012-10-01

The measurement of strong, self-generated electric fields (1-10 GVolts/m) in imploding capsules [1], their attribution to polarized (plasma) shock fronts [2], and the identification of plasma-enhanced binary species diffusion from barodiffusion and electrodiffusion [3] have led to a growing interest in the potential role of species separation in inertial-confinement-fusion (ICF) thermonuclear fuels. The potential for anomalous heating from transient frictional or resistive drag between D and T across a finite thickness shock front will be assessed and applied towards ignition thresholds and understanding some outstanding anomalies in the Omega implosion database.[4pt] [1] J.R. Rygg et al., Science 319, 1223 (2008); C.K. Li et al., Phys. Rev. Lett. 100, 225001 (2008).[0pt] [2] P.A. Amendt, J.L. Milovich, S.C. Wilks, C.K. Li, R.D. Petrasso and F.H. S'eguin, Plasma Phys. Control. Fusion 51, 124048 (2009).[0pt] [3] P. Amendt, C. Bellei and S.C. Wilks, Phys. Rev. Lett. (to appear).

Wetted foam liquid fuel ICF target experiments

International Nuclear Information System (INIS)

Olson, R E; Leeper, R J; Yi, S A; Kline, J L; Zylstra, A B; Peterson, R R; Shah, R; Braun, T; Biener, J; Kozioziemski, B J; Sater, J D; Biener, M M; Hamza, A V; Nikroo, A; Hopkins, L Berzak; Ho, D; LePape, S; Meezan, N B

2016-01-01

We are developing a new NIF experimental platform that employs wetted foam liquid fuel layer ICF capsules. We will use the liquid fuel layer capsules in a NIF sub-scale experimental campaign to explore the relationship between hot spot convergence ratio (CR) and the predictability of hot spot formation. DT liquid layer ICF capsules allow for flexibility in hot spot CR via the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. Our hypothesis is that the predictive capability of hot spot formation is robust and 1D-like for a relatively low CR hot spot (CR∼15), but will become less reliable as hot spot CR is increased to CR>20. Simulations indicate that backing off on hot spot CR is an excellent way to reduce capsule instability growth and to improve robustness to low-mode x-ray flux asymmetries. In the initial experiments, we will test our hypothesis by measuring hot spot size, neutron yield, ion temperature, and burn width to infer hot spot pressure and compare to predictions for implosions with hot spot CR's in the range of 12 to 25. Larger scale experiments are also being designed, and we will advance from sub-scale to full-scale NIF experiments to determine if 1D-like behavior at low CR is retained as the scale-size is increased. The long-term objective is to develop a liquid fuel layer ICF capsule platform with robust thermonuclear burn, modest CR, and significant α-heating with burn propagation. (paper)

Cryogenic-laser-fusion target implosion studies performed with the OMEGA uv-laser system

International Nuclear Information System (INIS)

Marshall, F.J.; Letzring, S.A.; Verdon, C.P.; Skupsky, S.; Keck, R.L.; Knauer, J.P.; Kremens, R.L.; Bradley, D.K.; Kessler, T.; Delettrez, J.; and others.

1989-01-01

A series of direct-drive laser-fusion implosion experiments was performed on cryogenically cooled, DT-filled glass microballoons with the OMEGA 24-beam uv (351-nm) laser system. The targets consisted of glass microballoons having radii of 100 to 150 μm, wall thicknesses of 3 to 7 μm, filled with DT gas at pressures of 75 to 100 atm. The targets were cooled to below the freezing point of DT, in situ, by a cryogenic target system. The targets were irradiated by approximately 1 to 1.2 kJ of uv light in 650-ps Gaussian pulses. The on-target irradiation uniformity was enhanced for these experiments by the use of distributed phase plates, which brought the estimated irradiation nonuniformities to ∼12% (σ rms ). Target performance was diagnosed by an array of x-ray, plasma, and nuclear instruments. The measured target performance showed ∼70% absorption, thermonuclear yields of 10 6 to 10 8 neutrons, and final fuel areal densities of 20 to 40 mg/cm 2 for the optimum targets examined in these experiments. Fuel densities at the time of thermonuclear neutron production, inferred from direct measurements of the fuel areal density, were in the range of 20 to 50 g/cm 3 (100 to 200 times the density of liquid DT) for the optimum targets

Proposal for a decision of the Council concerning the planning of a research- and education-program (1982-1986) on the field of thermonuclear fusion

International Nuclear Information System (INIS)

The thermonuclear fusion is in an early development state and has however in principle possible advantages which could be especially valuable for Europe. The primary fusion fuels (D, Li) are plentiful existent, wide spread and cheap (1 g natural Lithium could generate 15 MHW); both fuels and the end product of the reactions - Helium - are stable. From the nuclear-technological point of view a thermonuclear reactor could be built with high safety; the doubling time for breeding of new fuels in principle could be very short. These potential advantages however are balanced by certain disadvantages, e.g. high costs for the construction of a thermonuclear reactor etc. The research program, other possibilities and the costs are outlined. (orig./HT) [de

Economic comparison of fusion fuel cycles

International Nuclear Information System (INIS)

Brereton, S.J.; Kazimi, M.S.

1987-01-01

The economics of the DT, DD, and DHe fusion fuel cycles are evaluated by comparison on a consistent basis. The designs for the comparison employ HT-9 structure and helium coolant; liquid lithium is used as the tritium breeding material for the DT fuel cycle. The reactors are pulsed, superconducting tokamaks, producing 1200 MW of electric power. The DT and DD designs scan a range of values of plasma beta, assuming first stability scaling laws. The results indicate that on a purely economic basis, the DT fuel cycle is superior to both of the advanced fuel cycles. Geometric factors, materials limitations, and plasma beta were seen to have an impact on the Cost of Electricity (COE). The economics for the DD fuel cycle are more strongly affected by these parameters than is the DT fuel cycle. Fuel costs are a major factor in determining the COE for the DHe fuel cycle. Based on costs directly attributable to the fuel cycle, the DT fuel cycle appears most attractive. Technological advances, improved understanding of physics, or strides in advanced energy conversion schemes may result in altering the economic ranking of the fuel cycles indicated here. 7 refs., 6 figs., 2 tabs

The TFTR 40 MW neutral beam injection system and DT operations

International Nuclear Information System (INIS)

Stevenson, T.; O'Connor, T.; Garzotto, V.

1995-01-01

Since December 1993, TFTR has performed DT experiments using tritium fuel provided mainly by neutral beam injection. Significant alpha particle populations and reactor-like conditions have been achieved at the plasma core, and fusion output power has risen to a record 10.7 MW using a record 40 MW NB heating. Tritium neutral beams have injected into over 480 DT plasmas and greater than 500 kCi have been processed through the neutral beam gas, cryo, and vacuum systems. Beam tritium injections, as well as tritium feedstock delivery and disposal, have now become part of routine operations. Shot reliability with tritium is about 90% and is comparable to deuterium shot reliability. This paper describes the neutral beam DT experience including the preparations, modifications, and operating techniques that led to this high level of success, as well as the critical differences in beam operations encountered during DT operations. Also, the neutral beam maintenance and repair history during DT operations, the corrective actions taken, and procedures developed for handling tritium contaminated components are discussed in the context of supporting a continuous DT program

Epidemiology of a thermonuclear bomb-burst over Nashville, Tennessee: a theoretic study

International Nuclear Information System (INIS)

Quinn, R.W.

1983-01-01

A thermonuclear bomb explosion over any city in the world would have a devastating effect on the population and environment. For those who survive, with or without injuries, life would become primitive with little or no uncontaminated food or water, and with inadequate housing, fuel, and medical care, resulting in a breakdown of family and interpersonal relationships. This theoretic study of the potential outcome of a thermonuclear bomb-burst over Nashville, Tennessee, discusses epidemiologically the wide range of medical and psychologic effects from the direct trauma of blast and fire, widespread epidemics of otherwise controlled disease, long-term chronic illness, genetic damage, and catastrophic environmental havoc

MINBAR: A comprehensive study of 6000+ thermonuclear shell flashes from neutron stars

DEFF Research Database (Denmark)

Galloway, Duncan; in't Zand, J.J.M.; Chenevez, Jérôme

2014-01-01

Thermonuclear (type-I) X-ray bursts have been observed from accreting neutron stars since the early 1970s. These events serve as a valuable diagnostic tool to constrain the source distance; accretion rate; accreted fuel composition, and hence evolutionary status of the donor; and even the neutron...

Stabilization of burn conditions in a thermonuclear reactor using artificial neural networks

Science.gov (United States)

Vitela, Javier E.; Martinell, Julio J.

1998-02-01

In this work we develop an artificial neural network (ANN) for the feedback stabilization of a thermonuclear reactor at nearly ignited burn conditions. A volume-averaged zero-dimensional nonlinear model is used to represent the time evolution of the electron density, the relative density of alpha particles and the temperature of the plasma, where a particular scaling law for the energy confinement time previously used by other authors, was adopted. The control actions include the concurrent modulation of the D-T refuelling rate, the injection of a neutral He-4 beam and an auxiliary heating power modulation, which are constrained to take values within a maximum and minimum levels. For this purpose a feedforward multilayer artificial neural network with sigmoidal activation function is trained using a back-propagation through-time technique. Numerical examples are used to illustrate the behaviour of the resulting ANN-dynamical system configuration. It is concluded that the resulting ANN can successfully stabilize the nonlinear model of the thermonuclear reactor at nearly ignited conditions for temperature and density departures significantly far from their nominal operating values. The NN-dynamical system configuration is shown to be robust with respect to the thermalization time of the alpha particles for perturbations within the region used to train the NN.

Stabilization of burn conditions in a thermonuclear reactor using artificial neural networks

International Nuclear Information System (INIS)

Vitela, J.E.; Martinell, J.J.

1998-01-01

In this work we develop an artificial neural network (ANN) for the feedback stabilization of a thermonuclear reactor at nearly ignited burn conditions. A volume-averaged zero-dimensional nonlinear model is used to represent the time evolution of the electron density, the relative density of alpha particles and the temperature of the plasma, where a particular scaling law for the energy confinement time previously used by other authors, was adopted. The control actions include the concurrent modulation of the D-T refuelling rate, the injection of a neutral He-4 beam and an auxiliary heating power modulation, which are constrained to take values within a maximum and minimum levels. For this purpose a feedforward multilayer artificial neural network with sigmoidal activation function is trained using a back-propagation through-time technique. Numerical examples are used to illustrate the behaviour of the resulting ANN-dynamical system configuration. It is concluded that the resulting ANN can successfully stabilize the nonlinear model of the thermonuclear reactor at nearly ignited conditions for temperature and density departures significantly far from their nominal operating values. The NN-dynamical system configuration is shown to be robust with respect to the thermalization time of the alpha particles for perturbations within the region used to train the NN. (author)

Proposal for a decision of the EC Council concerning the planning of a research- and education-program (1982-1986) on the field of controlled thermonuclear fusion

International Nuclear Information System (INIS)

Anon.

1981-01-01

The thermonuclear fusion is in a early development state and has, however, in principle possible advantages which could be especially valuable for Europe: the primary fusion fuels (D, Li) are plentiful existent, wide spread and cheap (1 g natural Lithium could generate 15 MWh); both fuels and the end product of the reactions - Helium - are stable. From the nuclear-technological point of view a thermonuclear reactor could be built with high safety; the doubling time for breeding of new fuels in principle could be very short. These potential advantages, however, are balanced by certain disadvantages, e.g. high costs for the construction of a thermonuclear reactor etc. The research program, other possibilities and the costs are outlined. (orig./HT) [de

Tritium processing and management during D-T experiments on TFTR

International Nuclear Information System (INIS)

La Marche, P.H.; Anderson, J.L.; Gentile, C.A.; Hawryluk, R.J.; Hosea, J.; Kalish, M.; Kozub, T.; Murray, H.; Nagy, A.; Raftopoulos, S.

1994-11-01

TFTR performance has surpassed many of the previous tokamak records. This has been made possible by the use of tritium as fuel for DT plasma discharges. Stable operations of tritium systems provide for safe, routine DT operation of TFTR. In the preparation for DT operation, in the commissioning of the tritium systems and in the operation of the Nuclear Facility several key lessons have been learned. They include: the facility must take the lead in interpreting the applicable regulations and orders and then seek regulator approval; the use of ultra high vacuum technology in tritium system design and construction simplifies and enhances operations and maintenance; and central facility control under a single supervisory position is crucial to safely orchestrate operational and maintenance activities

Capabilities of a DT tokamak fusion neutron source for driving a spent nuclear fuel transmutation reactor

International Nuclear Information System (INIS)

Stacey, W.M.

2001-01-01

The capabilities of a DT fusion neutron source for driving a spent nuclear fuel transmutation reactor are characterized by identifying limits on transmutation rates that would be imposed by tokamak physics and engineering limitations on fusion neutron source performance. The need for spent nuclear fuel transmutation and the need for a neutron source to drive subcritical fission transmutation reactors are reviewed. The likely parameter ranges for tokamak neutron sources that could produce an interesting transmutation rate of 100s to 1000s of kg/FPY (where FPY stands for full power year) are identified (P fus ∼ 10-100 MW, β N ∼ 2-3, Q p ∼ 2-5, R ∼ 3-5 m, I ∼ 6-10 MA). The electrical and thermal power characteristics of transmutation reactors driven by fusion and accelerator spallation neutron sources are compared. The status of fusion development vis-a-vis a neutron source is reviewed. (author)

TFTR D-T results

International Nuclear Information System (INIS)

Meade, D.M.

1994-01-01

Temperatures, densities and confinement of deuterium plasmas confined in tokamaks have been achieved within the last decade that are approaching those required for a D-T reactor. As a result, the unique phenomena present in a D-T reactor plasma (D-T plasma confinement, alpha confinement, alpha heating and possible alpha driven instabilities) can now be studied in the laboratory. Recent experiments on the Tokamak Fusion Test Reactor (TFTR) have been the first magnetic fusion experiments to study plasmas with reactor fuel concentrations of tritium. The injection of ∼ 20 MW of tritium and 14 MW of deuterium neutral beams into the TFTR produced a plasma with a T/D density ratio of ∼1 and yielded a maximum fusion power of ∼ 9.2 MW. The fusion power density in the core of the plasma was ∼ 1.8 MW m -3 approximating that expected in a D-T fusion reactor. A TFTR plasma with T/D density ratio of ∼ 1 was found to have ∼ 20% higher energy confinement time than a comparable D plasma, indicating a confinement scaling with average ion mass, A, of τ E ∼ A 0.6 . The core ion temperature increased from 30 keV to 37 keV due to a 35% improvement of ion thermal conductivity. Using the electron thermal conductivity from a comparable deuterium plasma, about 50% of the electron temperature increase from 9 keV to 10.6 keV can be attributed to electron heating by the alpha particles. The ∼ 5% loss of alpha particles, as observed on detectors near the bottom edge of the plasma, was consistent with classical first orbit loss without anomalous effects. Initial measurements have been made of the confined energetic alphas and the resultant alpha ash density. At fusion power levels of 7.5 MW, fluctuations at the Toroidal Alfven Eigenmode frequency were observed by the fluctuation diagnostics. However, no additional alpha loss due to the fluctuations was observed

Imaging of High-Energy X-Ray Emission from Cryogenic Thermonuclear Fuel Implosions on the NIF

International Nuclear Information System (INIS)

Ma, T.

2012-01-01

Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide spectrally resolved time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered targets. Using bremsstrahlung assumptions, the measured absolute x-ray brightness allows for the inference of electron temperature, electron density, hot spot mass, mix mass, and pressure. Current inertial confinement fusion (ICF) experiments conducted on the National Ignition Facility (NIF) seek to indirectly drive a spherical implosion, compressing and igniting a deuterium-tritium fuel. This DT fuel capsule is cryogenically prepared as a solid ice layer surrounded by a low-Z ablator material. Ignition will occur when the hot spot approaches sufficient temperature (∼3-4 keV) and ρR (∼0.3 g/cm 2 ) such that alpha deposition can further heat the hot spot and generate a self-sustaining burn wave. During the implosion, the fuel mass becomes hot enough to emit large amounts of x-ray radiation, the spectra and spatial variation of which contains key information that can be used to evaluate the implosion performance. The Ross filter diagnostic employs differential filtering to provide spectrally resolved, time-integrated, absolute x-ray self-emission images of the imploded core of cryogenic layered targets.

Powerful lasers for thermonuclear fusion

International Nuclear Information System (INIS)

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

1977-01-01

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

Divertor, thermonuclear device and method of neutralizing high temperature plasma

International Nuclear Information System (INIS)

Ikegami, Hideo.

1995-01-01

The thermonuclear device comprises a thermonuclear reactor for taking place fusion reactions to emit fusion plasmas, and a divertor made of a hydrogen occluding material, and the divertor is disposed at a position being in contact with the fusion plasmas after nuclear fusion reaction. The divertor is heated by fusion plasmas after nuclear fusion reaction, and hydrogen is released from the hydrogen occluding material as a constituent material. A gas blanket is formed by the released hydrogen to cool and neutralize the supplied high temperature nuclear fusion plasmas. This prevents the high temperature plasmas from hitting against the divertor, elimination of the divertor by melting and evaporation, and solve a problem of processing a divertor activated by neutrons. In addition, it is possible to utilize hydrogen isotopes of fuels effectively and remove unnecessary helium. Inflow of impurities from out of the system can also be prevented. (N.H.)

Thermonuclear land of plenty

Science.gov (United States)

Gasior, P.

2014-11-01

Since the process of energy production in the stars has been identified as the thermonuclear fusion, this mechanism has been proclaimed as a future, extremely modern, reliable and safe for sustaining energetic needs of the humankind. However, the idea itself was rather straightforward and the first attempts to harness thermonuclear reactions have been taken yet in 40s of the twentieth century, it quickly appeared that physical and technical problems of domesticating exotic high temperature medium known as plasma are far from being trivial. Though technical developments as lasers, superconductors or advanced semiconductor electronics and computers gave significant contribution for the development of the thermonuclear fusion reactors, for a very long time their efficient performance was out of reach of technology. Years of the scientific progress brought the conclusions that for the development of the thermonuclear power plants an enormous interdisciplinary effort is needed in many fields of science covering not only plasma physics but also material research, superconductors, lasers, advanced diagnostic systems (e.g. spectroscopy, interferometry, scattering techniques, etc.) with huge amounts of data to be processed, cryogenics, measurement-control systems, automatics, robotics, nanotechnology, etc. Due to the sophistication of the problems with plasma control and plasma material interactions only such a combination of the research effort can give a positive output which can assure the energy needs of our civilization. In this paper the problems of thermonuclear technology are briefly outlined and it is shown why this domain can be a broad field for the experts dealing with electronics, optoelectronics, programming and numerical simulations, who at first glance can have nothing common with the plasma or nuclear physics.

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

Thermonuclear device

International Nuclear Information System (INIS)

Yagi, Yasuomi; Takahashi, Ken; Hashimoto, Hiroshi.

1984-01-01

Purpose: To improve the plasma confining performances by bringing the irregular magnetic fields nearly to zero and decreasing the absolute value of the irregular magnetic fields at every positions. Constitution: The winding direction of a plurality of coil elements, for instance, double pan cake coils of toroidal coils in a torus type or mirror type thermonuclear device are reversed to each other in their laminating direction, whereby the irregular magnetic fields due to the coil-stepped portions in each toroidal coils are brought nearly to zero. This enables to bring the average irregular magnetic fields as a whole in the thermonuclear device nearly to zero, as well as, decrease the absolute value of the irregular magnetic fields in each positions. Thus, the plasma confining performances can be improved. (Moriyama, K.)

MUON DETECTORS: DT

CERN Multimedia

M. Dallavalle

In the past months, the DT electronics has run in a stable and reliable way, demonstrated again through the CRAFT exercise. Operation when the CMS magnetic field was on has been satisfactory. The detector safety control and monitoring is improving constantly as the DT group accumulates running experience. The DT DAQ and DCS systems proved very stable during the intensive CRAFT period. The few issues that were identified by the DCS and on-line monitoring did not prevent the run to continue, so that the record of the DT in the data taking efficiency was very good. The long running period was also used to continue the transition from a system run by experts to one run by shifters, which was in the large part successful. Improvements, mostly in consolidation of error reporting, were identified and will be addressed in the coming shut-down. During the CRAFT data taking, DT triggered about 300 million cosmics with the magnet at 3.8T and the silicon strip tracker in the readout. Although a dedicated configuratio...

Heating and transport in TFTR D-T plasmas

International Nuclear Information System (INIS)

Zarnstorff, M.C.; Scott, S.D.

1994-01-01

The confinement and heating of supershot plasmas are significantly enhanced with tritium beam injection relative to deuterium injection in TFTR. The global energy confinement and local thermal transport are analyzed for deuterium and tritium fueled plasmas to quantify their dependence on the average mass of the hydrogenic ions. The radial profiles of the deuterium and tritium densities are determined from the DT fusion neutron emission profile

Spin-polarized fuel in ICF pellets

International Nuclear Information System (INIS)

Wakuta, Yoshihisa; Emoto, Nobuya; Nakao, Yasuyuki; Honda, Takuro; Honda, Yoshinori; Nakashima, Hideki.

1990-01-01

The use of parallel spin-polarized DT or D 3 He fuel increases the fusion cross-section by 50%. By implosion-burn simulation for inertially confined fusion (ICF) pellets of the spin-polarized fuels, we found that the input energy requirement could be reduced by nearly a fact of two. These pellets taken up here include large-high-aspect-ratio DT target proposed in ILE Osaka University and DT ignitor/D 3 He fuel pellet proposed by our group. We also found that the polarized state could survive during the implosion-burn phase. (author)

Wetted Foam Liquid DT Layer ICF Experiments at the NIF

Science.gov (United States)

Olson, R. E.; Leeper, R. J.; Peterson, R. R.; Yi, S. A.; Zylstra, A. B.; Kline, J. L.; Bradley, P. A.; Yin, L.; Wilson, D. C.; Haines, B. M.; Batha, S. H.

2016-10-01

A key physics issue in indirect-drive ICF relates to the understanding of the limitations on hot spot convergence ratio (CR), principally set by the hohlraum drive symmetry, the capsule mounting hardware (the ``tent''), and the capsule fill tube. An additional key physics issue relates to the complex process by which a hot spot must be dynamically formed from the inner ice surface in a DT ice-layer implosion. These physics issues have helped to motivate the development of a new liquid DT layer wetted foam platform at the NIF that provides an ability to form the hot spot from DT vapor and experimentally study and understand hot spot formation at a variety of CR's in the range of 12hot spot and the low adiabat cold fuel during the stagnation process and can allow for a fundamentally different (and potentially more robust) process of hot spot formation. This new experimental platform is currently being used in a series of experiments to discover a range of CR's at which DT layered implosions will have understandable performance - providing a sound basis from which to determine the requirements for ICF ignition. This work was performed under the auspices of the U. S. DOE by LANL under contract DE-AC52-06NA25396.

Tritium-management requirements for D-T fusion reactors (ETF, INTOR, FED)

International Nuclear Information System (INIS)

Finn, P.A.; Clemmer, R.G.; Misra, B.

1981-10-01

The successful operation of D-T fusion reactors will depend on the development of safe and reliable tritium-containment and fuel-recycle systems. The tritium handling requirements for D-T reactors were analyzed. The reactor facility was then designed from the viewpoint of tritium management. Recovery scenarios after a tritium release were generated to show the relative importance of various scenarios. A fusion-reactor tritium facility was designed which would be appropriate for all types of plants from the Engineering Test Facility (ETF), the International Tokamak Reactor (INTOR), and the Fusion Engineering Device (FED) to the full-scale power plant epitomized by the STARFIRE design

MUON DETECTORS: DT

CERN Multimedia

I. Redondo

2011-01-01

During the second quarter of 2011, the DT system has continued to operate successfully with a high fraction of good channels (>99 %) and causing extremely little downtime to CMS. The high fraction of operated channels did not come for free: DT requested 18 short UXC accesses in the 3 months from March to May 2011. The dominant causes for these interventions were HV related interventions (7), which typically affect a small fraction of a chamber, and interventions for dealing with overheated LV Anderson connectors (7), whose failure could affect larger fractions of the detector (a whole chamber, half a wheel). With respect to the CMS downtime, a successful effort with colleagues from the DT Track Finder of the Level-1 Trigger system allowed to overcome a relatively relevant source of downtime from DTTF FED Out-Of-Sync errors, which would appear randomly during data-taking. The DT group developed a system configuration that would make it possible to reproduce the error without beam, thereby sparing lumin...

Research into thermonuclear fusion

International Nuclear Information System (INIS)

Schumacher, U.

1989-01-01

The experimental and theoretical studies carried out in close international cooperation in the field of thermonuclear fusion by magnetic plasma confinement have achieved such progress towards higher plasma temperatures and densities, longer confinement times and, thus, increased fusion product, that emphasis now begins to be shifted from problems of physics to those of technology as a next major step is being prepared towards a large international project (ITER) to achieve thermonuclear burning. The generation and maintenance of a burning fusion plasma in an experimental physics phase will be followed by a phase of technical materials studies at high fluxes of fusion neutrons. These goals have been pursued since 1983 by an international study group at Garching working on the design of a Next European Torus (NET). Since May 1988, an international study group comprising ten experts each from the USSR, USA, Japan, and the European Community has begun to work on a design draft of ITER (International Thermonuclear Experimental Reactor) in Garching under the auspices of IAEA. (orig.) [de

Controlled thermonuclear fusion

International Nuclear Information System (INIS)

Sakanaka, P.H.

1984-01-01

A simplified review on the status of the controlled thermonuclear fusion research aiming to present the motivation, objective, necessary conditions and adopted methods to reach the objective. (M.C.K.) [pt

Production of ultrapure D-T gas by removal of molecular tritium by selective adsorption

International Nuclear Information System (INIS)

Maienschein, J.L.; Hudson, R.S.; Tsugawa, R.T.; Fearon, E.M.; Souers, P.C.; Collins, G.W.

1992-01-01

Production of molecular deuterium-tritium (D-T) with very low molecular tritium (T 2 ) is necessary for application as a nuclear spin polarized fuel. Selective adsorption of hydrogen isotopes on zeolites or alumina can provide the separation needed to produce D-T with very low T 2 . Use of an absorption column at 20-25 K offers low inventory, compact size, and rapid operation, in comparison with conventional separation techniques such as cryogenic distillation or thermal diffusion. In this paper, the authors discuss principles of absorption, and describe a calculational model of the absorption column and operational implications revealed by it. The authors show experimental proof-of-principle data for removal of T 2 from D-T with an adsorption column operated at 23 K

MUON DETECTORS: DT

CERN Multimedia

Marco Dallavalle

2013-01-01

The DT group is undertaking substantial work both for detector maintenance and for detec-tor upgrade. Maintenance interventions on chambers and minicrates require close collaboration between DT, RPC and HO, and are difficult because they depend on the removal of thermal shields and cables on the front and rear of the chambers in order to gain access. The tasks are particularly critical on the central wheel due to the presence of fixed services. Several interventions on the chambers require extraction of the DT+RPC package: a delicate operation due to the very limited space for handling the big chambers, and the most dangerous part of the DT maintenance campaign. The interventions started in July 2013 and will go on until spring 2014. So far out of the 16 chambers with HV problems, 13 have been already repaired, with a global yield of 217 recovered channels. Most of the observed problems were due to displacement of impurities inside the gaseous volume. For the minicrates and FE, repairs occurred on 22 chambe...

MUON DETECTORS: DT

CERN Multimedia

M. Dallavalle

2012-01-01

  It is three years without access to the chambers and their front-end electronics, and the DT collaboration is preparing for a substantial work of maintenance and upgrade during LS1 in 2013/14. Even though, thanks to the constant care provided by the on-site operation team, the fraction of good channels is still very high at 98.8% and the downtime caused to CMS as a consequence of DT failures is to-date <1%, the original robustness of the system has deteriorated and many small local interventions are needed to restore it. The excellent stability and linearity with luminosity of the DT trigger rates has been
exploited and currently DT rates are published as an additional online luminometer in WBM.
The calibration is calculated from the correlation with pixel luminosity for 2011 data while
a preliminary independent calibration for 2012 data based on the analysis of Van der Meer scan data
 (project of CERN summer student Jessica Turner) has to be refined i...

Review of D-T Experiments Relevant to Burning Plasma Issues

International Nuclear Information System (INIS)

Hawryluk, R.J.

2001-01-01

Progress in the performance of tokamak devices has enabled not only the production of significant bursts of fusion energy from deuterium-tritium (D-T) plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. The TFTR and JET, in conjunction with the worldwide fusion effort, have studied a broad range of topics including magnetohydrodynamic stability, transport, wave-particle interactions, the confinement of energetic particles, and plasma boundary interactions. The D-T experiments differ in three principal ways from previous experiments: isotope effects associated with the use of deuterium-tritium fuel, the presence of fusion-generated alpha particles, and technology issues associated with tritium handling and increased activation. The effect of deuterium-tritium fuel and the presence of alpha particles is reviewed and placed in the perspective of the much large r worldwide database using deuterium fuel and theoretical understanding. Both devices have contributed substantially to addressing the scientific and technical issues associated with burning plasmas. However, future burning plasma experiments will operate with larger ratios of alpha heating power to auxiliary power and will be able to access additional alpha-particle physics issues. The scientific opportunities for extending our understanding of burning plasmas beyond that provided by current experiments is described

Ecological problems of thermonuclear energetics. Review

Energy Technology Data Exchange (ETDEWEB)

Sivintsev, Yu V

1980-01-01

A review of preliminary quantitative estimates of radiation hazard of thermonuclear reactors is presented. Main attention is given to three aspects: nonradiation effect on environment, radionuclide blow-ups at normal operation and emergency situations with their consequences. The given data testify to great radiological advantages of thermonuclear energetics as compared with the modern nuclear energetics with thermal and prospective fast reactors.

Thermonuclear fusion

International Nuclear Information System (INIS)

Weisse, J.

2000-01-01

This document takes stock of the two ways of thermonuclear fusion research explored today: magnetic confinement fusion and inertial confinement fusion. The basic physical principles are recalled first: fundamental nuclear reactions, high temperatures, elementary properties of plasmas, ignition criterion, magnetic confinement (charged particle in a uniform magnetic field, confinement and Tokamak principle, heating of magnetized plasmas (ohmic, neutral particles, high frequency waves, other heating means), results obtained so far (scale laws and extrapolation of performances, tritium experiments, ITER project), inertial fusion (hot spot ignition, instabilities, results (Centurion-Halite program, laser experiments). The second part presents the fusion reactor and its associated technologies: principle (tritium production, heat source, neutron protection, tritium generation, materials), magnetic fusion (superconducting magnets, divertor (role, principle, realization), inertial fusion (energy vector, laser adaptation, particle beams, reaction chamber, stresses, chamber concepts (dry and wet walls, liquid walls), targets (fabrication, injection and pointing)). The third chapter concerns the socio-economic aspects of thermonuclear fusion: safety (normal operation and accidents, wastes), costs (costs structure and elementary comparison, ecological impact and external costs). (J.S.)

Blanket for thermonuclear device

International Nuclear Information System (INIS)

Ozawa, Yoshihiro; Uda, Tatsuhiko; Maki, Koichi.

1993-01-01

The present invention provides a blanket of a thermonuclear device which produces tritium fuels consumed in plasmas while converting neutrons generated in the plasmas into heat energy. That is, zirconium is coated to at least one of neutron breeder pebbles and breeder pebbles, to suppress reaction between them by being in direct contact with each other at a high temperature. Further, fins are attached to a cooling pipe at a pitch smaller than the diameter of both of the pebbles, to prevent direct contact at whole surface of the pebbles and the cooling pipe, which would lower a temperature excessively. The length of the fin is controlled to control the thickness of a helium gas gap. With such constitution, direct contact of neutron breeder pebbles and the breeder pebble which are to be filled and mixed, and tend to react at a high temperature, can be prevented. The temperature of the breeding blanket is reliably prevented from lowering below a tritium emitting temperature. The structure is simplified and the production is facilitated. (I.S.)

Inertial-confinement-fusion targets

International Nuclear Information System (INIS)

Hendricks, C.D.

1982-01-01

Much of the research in laser fusion has been done using simple ball on-stalk targets filled with a deuterium-tritium mixture. The targets operated in the exploding pusher mode in which the laser energy was delivered in a very short time (approx. 100 ps or less) and was absorbed by the glass wall of the target. The high energy density in the glass literally exploded the shell with the inward moving glass compressing the DT fuel to high temperatures and moderate densities. Temperatures achieved were high enough to produce DT reactions and accompanying thermonuclear neutrons and alpha particles. The primary criteria imposed on the target builders were: (1) wall thickness, (2) sphere diameter, and (3) fuel in the sphere

Experimental Investigation of Muon-Catalyzed $dt$ Fusion in Wide Ranges of $D/T$ Mixture Conditions

CERN Document Server

Bom, V R; Demin, D L; van Eijk, C W E; Faifman, M P; Filchenkov, V V; Golubkov, A N; Grafov, N N; Grishenchkin, S K; Gritsaj, K I; Klevtsov, V G; Konin, A D; Kuryakin, A V; Medved', S V; Musyaev, R K; Perevozchikov, V V; Rudenko, A I; Sadetsky, S M; Vinogradov, Yu I; Yukhimchuk, A A; Yukhimchuk, S A; Zinov, V G; Zlatoustovskii, S V

2004-01-01

A vast program of the experimental investigation of muon-catalyzed $dt$ fusion was performed at the JINR Phasotron. Parameters of the $dt$ cycle were obtained in a wide range of $D/T$ mixture conditions: temperatures of $20\\div 800$ K, densities of $0.2\\div1.2$ LHD and tritium concentrations of $15\\div 86\\%$. The results obtained are summarized.

Important problems of future thermonuclear reactors*

Directory of Open Access Journals (Sweden)

Sadowski Marek J.

2015-06-01

Full Text Available This paper concerns important and difficult problems connected with a design and construction of thermonuclear reactors, which have to use nuclear fusion reactions of heavy isotopes of hydrogen, i.e., deuterium (D and tritium (T. There are described conditions in which such reactions can occur, and different methods of a high-temperature plasma generation, i.e., high-current electrical discharges, intense microwave pulses, and injection of energetic neutral atoms (NBI. There are also presented experimental facilities which can contain hot plasma for an appropriate period, and particularly so-called tokamaks. The second part presents the technical problems which must be solved in order to build a thermonuclear reactor, that might be used for energetic purposes. There are considered problems connected with a choice of constructional materials for a vacuum chamber, its internal parts, external windings generating a magnetic field, and necessary shields. The next part considers the handling of radioactive tritium; the using of alpha particles (4He for additional heating of plasma; recuperation of hydrogen isotopes absorbed in the tokamak internal parts, and a removal of a helium excess. There is presented a scheme of a future thermonuclear power plant and critical comments on a road map which should enable the construction of an industrial thermonuclear reactor (DEMO.

Structure of thermonuclear reactor wall

International Nuclear Information System (INIS)

Yamazaki, Seiichiro.

1991-01-01

In a thermonuclear reactor wall, there has been a worry that the brazing material is melted by high temperature heat and particle load, to peel off the joined portion and the protecting material is destroyed by temperature elevation, to expose the heat sink material. Then, in the reactor core structures of a thermonuclear reactor, such as a divertor plate comprising a protecting material made of carbon material and the heat sink material joined by brazing, a plate material made of a so-called refractory metal having a high atomic number such as tungsten, molybdenum or the alloy thereof is embedded or attached to an accurate position of the protecting material. This can prevent the brazing portion from destruction by escaping electrons generated upon occurrence of abnormality in the thermonuclear reactor, and peeling or destroy of the protecting material and the heat sink material. Sufficient characteristics of plasmas can always be maintained by disposing a material having a small atomic number, for example, carbon material, to the position facing to the plasmas. (N.H.)

Comparison of post-contrast 3D-T1-MPRAGE, 3D-T1-SPACE and 3D-T2-FLAIR MR images in evaluation of meningeal abnormalities at 3-T MRI.

Science.gov (United States)

Jeevanandham, Balaji; Kalyanpur, Tejas; Gupta, Prashant; Cherian, Mathew

2017-06-01

This study was to assess the usefulness of newer three-dimensional (3D)-T 1 sampling perfection with application optimized contrast using different flip-angle evolutions (SPACE) and 3D-T 2 fluid-attenuated inversion recovery (FLAIR) sequences in evaluation of meningeal abnormalities. 78 patients who presented with high suspicion of meningeal abnormalities were evaluated using post-contrast 3D-T 2 -FLAIR, 3D-T 1 magnetization-prepared rapid gradient-echo (MPRAGE) and 3D-T 1 -SPACE sequences. The images were evaluated independently by two radiologists for cortical gyral, sulcal space, basal cisterns and dural enhancement. The diagnoses were confirmed by further investigations including histopathology. Post-contrast 3D-T 1 -SPACE and 3D-T 2 -FLAIR images yielded significantly more information than MPRAGE images (p evaluation of meningeal abnormalities and when used in combination have the maximum sensitivity for leptomeningeal abnormalities. The negative-predictive value is nearly 100%, where no leptomeningeal abnormality was detected on these sequences. Advances in knowledge: Post-contrast 3D-T 1 -SPACE and 3D-T 2 -FLAIR images are more useful than 3D-T 1 -MPRAGE images in evaluation of meningeal abnormalities.

Merging White Dwarfs and Thermonuclear Supernovae

OpenAIRE

van Kerkwijk, Marten H.

2012-01-01

Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure, and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and our suggestion that these supernovae instead resul...

Advance in physics of laser thermonuclear fusion

International Nuclear Information System (INIS)

Afanasev, J.; Basov, N.; Gamalij, J.; Krokhin, O.; Rozanov, V.

1977-01-01

A survey is given of current advance in the physics of laser thermonuclear fusion (LTF). The LTF physical model is discussed with regard to the optimal laser-target systems not only for attaining the physical limit but also for future thermonuclear reactors. The basic physical principles of LTF are formulated which make use of the fact that in focusing laser radiation on the surface of a substance a high density may be attained of the energy flux (10 5 to 10 6 J) and thereby also a high velocity of energy release in the substance. A detailed description is given of the processes which take place in laser irradiation of a spherical target. The problem is discussed of hydrodynamic stability in the compression of matter in laser thermonuclear targets, the concept is explained of the physical threshold of a thermonuclear reaction in laser excitation as are the conditions for attaining this threshold. The quantitative criterion is examined of the attainment of the physical threshold of LTF for pulsed systems. (B.S.)

Tokamak Fusion Test Reactor D-T results

International Nuclear Information System (INIS)

Meade, D.M.

1995-01-01

Temperatures, densities and confinement of deuterium plasmas confined in tokamaks have been achieved within the last decade that are approaching those required for a D-T reactor. As a result, the unique phenomena present in a D-T reactor plasma (D-T plasma confinement, α confinement, α heating and possible α-driven instabilities) can now be studied in the laboratory. Recent experiments on the Tokamak Fusion Test Reactor (TFTR) have been the first magnetic fusion experiments to study plasmas with reactor fuel concentrations of tritium. The injection of about 20MW of tritium and 14MW of deuterium neutral beams into the TFTR produced a plasma with a T-to-D density ratio of about 1 and yielding a maximum fusion power of about 9.2MW. The fusion power density in the core of the plasma was about 1.8MWm -3 , approximating that expected in a D-T fusion reactor. A TFTR plasma with a T-to-D density ratio of about 1 was found to have about 20% higher energy confinement time than a comparable D plasma, indicating a confinement scaling with average ion mass A of τ E ∝A 0.6 . The core ion temperature increased from 30 to 37keV owing to a 35% improvement of ion thermal conductivity. Using the electron thermal conductivity from a comparable deuterium plasma, about 50% of the electron temperature increase from 9 to 10.6keV can be attributed to electron heating by the α particles. The approximately 5% loss of α particles, as observed on detectors near the bottom edge of the plasma, was consistent with classical first orbit loss without anomalous effects. Initial measurements have been made of the confined high energy α particles and the resultant α ash density. At fusion power levels of 7.5MW, fluctuations at the toroidal Alfven eigen-mode frequency were observed by the fluctuation diagnostics. However, no additional α loss due to the fluctuations was observed. (orig.)

[International Thermonuclear Experimental Reactor support

International Nuclear Information System (INIS)

Dean, S.O.

1990-01-01

This report summarizes the activities under LLNL Purchase Order B089367, the purpose of which is to ''support the University/Lawrence Livermore National Laboratory Magnetic Fusion Program by evaluating the status of research relative to other national and international programs and assist in long-range plans and development strategies for magnetic fusion in general and for ITER in particular.'' Two specific subtasks are included: ''to review the LLNL Magnet Technology Development Program in the context of the International Thermonuclear Experimental Reactor Design Study'' and to ''assist LLNL to organize and prepare materials for an International Thermonuclear Experimental Reactor Design Study information meeting.''

Controlled thermonuclear fusion

International Nuclear Information System (INIS)

Trocheris, M.

1975-01-01

An outline is given of the present position of research into controlled fusion. After a brief reminder of the nuclear reactions of fusion and the principle of their use as a source of energy, the results obtained by the method of magnetic confinement are summarized. Among the many solutions that have been imagined and tried out to achieve a magnetic containing vessel capable of holding the thermonuclear plasma, the devices of the Tokamak type have a good lead and that is why they are described in greater detail. An idea is then given of the problems that arise when one intends conceiving the thermonuclear reactor based on the principle of the Tokamaks. The last section deals with fusion by lasers which is a new and most attractive alternative, at least from the viewpoint of basis physics. The report concludes with an indication of the stages to be passed through to reach production of energy on an industrial scale [fr

Thermonuclear model for high energy transients

International Nuclear Information System (INIS)

Woosley, S.E.

1982-01-01

The thermonuclear model for x- and γ-ray bursts is discussed. Different regimes of nuclear burning are reviewed, each appropriate to a given range of (steady state) accretion rate. Accretion rates in the range 10 -14 to 10 -8 Msub solar y -1 all appear capable of producing x-ray transients of various durations and intervals. Modifications introduced by radiatively driven mass loss, the thermal inertia of the envelope, different burning mechanisms, and two-dimensional considerations are discussed as are difficulties encountered when the thermonuclear model is confronted with observations of rapidly recurrent bursts (less than or equal to 10 min), and super-Eddington luminosities and temperatures. Results from a numerical simulation of a combined hydrogen-helium runaway initiated at pycnonuclear density are presented for the first time. The thermonuclear model for γ-ray bursts is also reviewed and updated, particularly with regard to the breakdown of the steady state hypothesis employed in previous work. Solely on the basis of nuclear instability, γ-ray bursts of various types appear possible for a very broad variety of accretion rates (approx. 10 -17 to approx. 10 -11 Msub solar y -1 ) although other considerations may restrict this range. The thermonuclear model appears capable of yielding a great diversity of high energy transient phenomena for various accretion rates, magnetic field configurations, and neutron star envelope histories

Advanced-fuel reversed-field pinch reactor (RFPR)

International Nuclear Information System (INIS)

Hagenson, R.L.; Krakowski, R.A.

1981-10-01

The utilization of deuterium-based fuels offers the potential advantages of greater flexibility in blanket design, significantly reduced tritium inventory, potential reduction in radioactivity level, and utilization of an inexhaustible fuel supply. The conventional DT-fueled Reversed-Field Pinch Reactor (RFPR) designs are reviewed, and the recent extension of these devices to advanced-fuel (catalyzed-DD) operation is presented. Attractive and economically competitive DD/RFPR systems are identified having power densities and plasma parameters comparable to the DT systems. Converting an RFP reactor from DT to DD primarily requires increasing the magnetic field levels a factor of two, still requiring only modest magnet coil fields (less than or equal to 4 T). When compared to the mainline tokamak, the unique advantages of the RFP (e.g., high beta, low fields at the coils, high ohmic-heating power densities, unrestricted aspect ratio) are particularly apparent for the utilization of advanced fuels

Demonstration of thermonuclear conditions in magnetized liner inertial fusion experiments

International Nuclear Information System (INIS)

Gomez, M. R.; Slutz, S. A.; Sefkow, A. B.; Hahn, K. D.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Ruiz, C. L.; Sinars, D. B.; Harding, E. C.; Jennings, C. A.; Awe, T. J.; Geissel, M.; Rovang, D. C.; Smith, I. C.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Harvey-Thompson, A. J.; Hess, M. H.

2015-01-01

The magnetized liner inertial fusion concept [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] utilizes a magnetic field and laser heating to relax the pressure requirements of inertial confinement fusion. The first experiments to test the concept [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] were conducted utilizing the 19 MA, 100 ns Z machine, the 2.5 kJ, 1 TW Z Beamlet laser, and the 10 T Applied B-field on Z system. Despite an estimated implosion velocity of only 70 km/s in these experiments, electron and ion temperatures at stagnation were as high as 3 keV, and thermonuclear deuterium-deuterium neutron yields up to 2 × 10 12 have been produced. X-ray emission from the fuel at stagnation had widths ranging from 50 to 110 μm over a roughly 80% of the axial extent of the target (6–8 mm) and lasted approximately 2 ns. X-ray yields from these experiments are consistent with a stagnation density of the hot fuel equal to 0.2–0.4 g/cm 3 . In these experiments, up to 5 × 10 10 secondary deuterium-tritium neutrons were produced. Given that the areal density of the plasma was approximately 1–2 mg/cm 2 , this indicates the stagnation plasma was significantly magnetized, which is consistent with the anisotropy observed in the deuterium-tritium neutron spectra. Control experiments where the laser and/or magnetic field were not utilized failed to produce stagnation temperatures greater than 1 keV and primary deuterium-deuterium yields greater than 10 10 . An additional control experiment where the fuel contained a sufficient dopant fraction to substantially increase radiative losses also failed to produce a relevant stagnation temperature. The results of these experiments are consistent with a thermonuclear neutron source

Controlled thermonuclear fusion

CERN Document Server

Bobin, Jean Louis

2014-01-01

The book is a presentation of the basic principles and main achievements in the field of nuclear fusion. It encompasses both magnetic and inertial confinements plus a few exotic mechanisms for nuclear fusion. The state-of-the-art regarding thermonuclear reactions, hot plasmas, tokamaks, laser-driven compression and future reactors is given.

Blankets for thermonuclear device

International Nuclear Information System (INIS)

Maki, Koichi; Fukumoto, Hideshi.

1986-01-01

Purpose: To produce tritium more than consumed, through thermonuclear reaction. Constitution: The energy spectrum of neutron generated by neutron multiplying reaction in a neutron multiplying blanket and moderated neutrons has a large ratio in a low energy section. In the low-energy absorption region of stainless steel which is a material of cooling pipes constituting a neutron multiplying blanket cooling channel, the neutrons are absorbed, lessening the neutron multiplying effect. To prevent this, the neutron multiplying blanket cooling channel is covered with tritium breeding blankets, thereby enabling the production of a substantially great amount of tritium more than the amount of tritium to be consumed by the thermonuclear reaction by preventing neutron absorption by the component materials of the cooling channel, improving the tritium breeding ratio by 20 to 25 %, and increasing the efficiency of use of neutrons for tritium generation. (Horiuchi, T.)

Control of TFTR during DT operations

International Nuclear Information System (INIS)

Pearson, G.G.; Alling, P.D.; Blanchard, W.; Camp, R.A.; Hawryluk, R.J.; Hosea, J.C.; Nagy, A.

1995-01-01

Since beginning routine D-T operations in December, 1993, there have been more than 500 DT plasmas and approximately 600,000 Ci of tritium processed through TFTR culminating in greater than 10 MW of fusion power produced in a single discharge in November, 1994. These performance levels were achieved while maintaining the highest levels of personnel and equipment safety. Prior to D-T operations, a Chain of Command structure and a TFTR Shift Supervisor (TFTRSS) position were developed for centralized control of the facility with all subsystems reporting to this position. A comprehensive surveillance system was incorporated such that the TFTR SS could easily review the operational readiness of subsystems for D-T operations. A TFTR SS Station was constructed to facilitate monitoring and control of TFTR. This station includes a camera system, FAX, a networked personal computer, a computerized tritium monitor and control system and a hardware interlock system. In the transition from D-D to D-T operations, TFTR's procedures were reviewed/revised and a number of additional procedures developed for control of activities at the facility. This paper details the equipment, administrative and organizational configurations used for controlling TFTR during D-T operations

Development of innovative fuelling systems for fusion energy science

International Nuclear Information System (INIS)

Gouge, M.J.; Baylor, L.R.; Combs, S.K.; Fisher, P.W.

1996-01-01

The development of innovative fueling systems in support of magnetic fusion energy, particularly the International Thermonuclear Experimental Reactor (ITER), is described. The ITER fuelling system will use a combination of deuterium-tritium (D-T) gas puffing and pellet injection to achieve and maintain ignited plasmas. This combination will provide a flexible fuelling source with D-T pellets penetrating beyond the separatrix to sustain the ignited fusion plasma and with deuterium-rich gas fuelling the edge region to meet divertor requirements in a process called isotopic fuelling. More advanced systems with potential for deeper penetration, such as multistage pellet guns and compact toroid injection, are also described

Thermonuclear energy and the power industry in the future

International Nuclear Information System (INIS)

Velikhov, E.P.

1986-01-01

The leader of the USSR thermonuclear program, the vicepresident of the Academy of Science, comrade Velikhov tells about the modern state and perspective of thermonuclear investigations, as well as about the problems on the international cooperation in this field

TFTR DT preparation project status

Energy Technology Data Exchange (ETDEWEB)

Perry, E.D.; Dudek, L.E.

1993-11-01

The Tokamak Fusion Test Reactor (TFTR) research program is preparing to commence the first high power Deuterium-Tritium (DT) experiments of the US Fusion Program. Hardware upgrades to TFTR required for DT operations have been completed. This paper discusses these hardware preparations.

Plasma and controlled thermonuclear reaction

Energy Technology Data Exchange (ETDEWEB)

Kapitsa, P L [AN SSSR, Moscow. Inst. Fizicheskikh Problem

1980-06-01

Two contemporary trends of research are characterized aiming at the thermonuclear reactor, viz., tokamak type equipment and pulsed heating of a deuterium-tritium mixture using focused laser light. There is a third trend based on the use of high-power continuous wave (CW) microwave generators which allow producing a rope discharge. The design is described of an anticipated CW thermonuclear reactor. Using current experimental facilities, a continuous high-frequency discharge can be obtained at a pressure of 25 atm and electron temperature of 50 million K. The major problem involved in the design of a CW reactor is the heating of ions to the same temperature as the electron temperature and the reduction in ion gas thermal conductivity.

MUON DETECTORS: DT

CERN Multimedia

R.Carlin

2010-01-01

DT operation during 2010 LHC collisions, both in proton-proton and heavy ions, has been outstanding. The DT downtime has been below 0.1% throughout the whole year, mainly caused by the manual Resync commands that took around a minute for being processed. An automatic resynchronisation procedure has been enabled by August 27 and since then the downtime has been negligible (though constantly monitored). The need for these Resync commands is related to sporadic noise events that occasionally fill the RO buffers or unlock the readout links. Their rate is low, in the order of a few per week. Besides that, only one pp collisions run (1 hour 30 minutes run) has been marked as bad for DT, because of an incident with a temperature sensor that triggered a false alarm and powered off one wheel. Nevertheless, quite a large number of interventions (>30) have been made in the cavern during the year, in order to keep such a large fraction of the detector operational. Most of those are due to the overheating of the ...

MUON DETECTORS: DT

CERN Multimedia

M. Dallavalle

2013-01-01

  It is three years since the last access to the chambers and their front-end electronics, and the DT collaboration is preparing for substantial maintenance and upgrade work LS1 in 2013-’14. The original robustness of the system has deteriorated and many small local interventions are needed to restore it, even though, thanks to the constant care provided by the on-site operation team, the fraction of good channels has still been very high (98.8%) during the 2012 data taking, and the downtime caused to CMS as a consequence of DT failures is to-date <1%. The upgrade activities planned for the LS1 evolve in good accordance to the schedule, both for the theta Trigger Board (TTRB) replacement and for the Sector Collector (SC) relocation from UXC to USC. The TTRB work aims at reconstituting the stock of spare boards for the long-term operation of the chamber minicrates. With the SC work, data and trigger primitives from each of the 250 DT chambers will be available in USC on optical fi...

MUON DETECTORS: DT

CERN Multimedia

I. Redondo Fernandez

2011-01-01

The DT system has operated successfully during the entire 2011 data-taking: the fraction of good channels was always >99.4 % and the downtime caused to CMS amounts to a few inverse picobarns. This excellent performance does not come without a price: the DT group requested more than 30 short accesses to the underground experimental cavern (UXC).  A large fraction of interventions was for dealing with overheated LV Anderson connectors, whose failure can affect larger sections of the detector (a whole chamber, or half a wheel of the CMS barrel, etc.). A crash programme for reworking those connections will take place during the Year-End Technical Stop. The system of six vd chambers (VDC) that were installed on the DT exhaust gas line have operated successfully. The VDCs are small drift chambers the size of a shoebox that measure the drift velocity every 10 minutes. Possible deviations from the nominal value could be caused by a contamination of the gas mixture or changes in pressure or temperat...

Rates of Thermonuclear Reactions in Dense Plasmas

International Nuclear Information System (INIS)

Tsytovich, V.N.; Bornatici, M.

2000-01-01

The problem of plasma screening of thermonuclear reactions has attracted considerable scientific interest ever since Salpeter's seminal paper, but it is still faced with controversial statements and without any definite conclusion. It is of relevant importance to thermonuclear reactions in dense astrophysical plasmas, for which charge screening can substantially affect the reaction rates. Whereas Salpeter and a number of subsequent investigations have dealt with static screening, Carraro, Schafer, and Koonin have drawn attention to the fact that plasma screening of thermonuclear reactions is an essentially dynamic effect. In addressing the issue of collective plasma effects on the thermonuclear reaction rates, the first critical overview of most of the work carried out so far is presented and the validity of the test particle approach is assessed. In contrast to previous investigations, we base our description on the kinetic equation for nonequilibrium plasmas, which accounts for the effects on the rates of thermonuclear reactions of both plasma fluctuations and screening and allows one to analyze explicitly the effects of the fluctuations on the reaction rates. Such a kinetic formulation is more general than both Salpeter's approach and the recently developed statistical approaches and makes it possible to obtain a more comprehensive understanding of the problem. A noticeable result of the fluctuation approach is that the static screening, which affects both the interaction and the self-energy of the reacting nuclei, does not affect the reaction rates, in contrast with the results obtained so far. Instead, a reduction of the thermonuclear reaction rates is obtained as a result of the effect of plasma fluctuations related to the free self-energy of the reacting nuclei. A simple physical explanation of the slowing down of the reaction rates is given, and the relation to the dynamically screened test particle approach is discussed. Corrections to the reaction rates

Controlled thermonuclear fusion reactors

International Nuclear Information System (INIS)

Walstrom, P.L.

1976-01-01

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

Max dD/Dt: A Novel Parameter to Assess Fetal Cardiac Contractility and a Substitute for Max dP/Dt.

Science.gov (United States)

Fujita, Yasuyuki; Kiyokoba, Ryo; Yumoto, Yasuo; Kato, Kiyoko

2018-07-01

Aortic pulse waveforms are composed of a forward wave from the heart and a reflection wave from the periphery. We focused on this forward wave and suggested a new parameter, the maximum slope of aortic pulse waveforms (max dD/dt), for fetal cardiac contractility. Max dD/dt was calculated from fetal aortic pulse waveforms recorded with an echo-tracking system. A normal range of max dD/dt was constructed in 105 healthy fetuses using linear regression analysis. Twenty-two fetuses with suspected fetal cardiac dysfunction were divided into normal and decreased max dD/dt groups, and their clinical parameters were compared. Max dD/dt of aortic pulse waveforms increased linearly with advancing gestational age (r = 0.93). The decreased max dD/dt was associated with abnormal cardiotocography findings and short- and long-term prognosis. In conclusion, max dD/dt calculated from the aortic pulse waveforms in fetuses can substitute for max dP/dt, an index of cardiac contractility in adults. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

Catalyzed deuterium fueled reversed-field pinch reactor assessment

International Nuclear Information System (INIS)

Dobrott, D.

1985-01-01

This study is part of a Department of Energy supported alternate fusion fuels program at Science Applications International Corporation. The purpose of this portion of the study is to perform an assessment of a conceptual compact reversed-field pinch reactor (CRFPR) that is fueled by the catalyzed-deuterium (Cat-d) fuel cycle with respect to physics, technology, safety, and cost. The Cat-d CRFPR is compared to a d-t fueled fusion reactor with respect to several issues in this study. The comparison includes cost, reactor performance, and technology requirements for a Cat-d fueled CRFPR and a comparable cost-optimized d-t fueled conceptual design developed by LANL

Capacitor requirements for controlled thermonuclear experiments and reactors

International Nuclear Information System (INIS)

Boicourt, G.P.; Hoffman, P.S.

1975-01-01

Future controlled thermonuclear experiments as well as controlled thermonuclear reactors will require substantial numbers of capacitors. The demands on these units are likely to be quite severe and quite different from the normal demands placed on either present energy storage capacitors or present power factor correction capacitors. It is unlikely that these two types will suffice for all necessary Controlled Thermonuclear Research (CTR) applications. The types of capacitors required for the various CTR operating conditions are enumerated. Factors that influence the life, cost and operating abilities of these types of capacitors are discussed. The problems of capacitors in a radiation environment are considered. Areas are defined where future research is needed. Some directions that this research should take are suggested. (U.S.)

Capacitor requirements for controlled thermonuclear experiments and reactors

International Nuclear Information System (INIS)

Boicourt, G.P.; Hoffman, P.S.

1975-01-01

Future controlled thermonuclear experiments as well as controlled thermonuclear reactors will require substantial numbers of capacitors. The demands on these units are likely to be quite severe and quite different from the normal demands placed on either present energy storage capacitors or present power factor correction capacitors. It is unlikely that these two types will suffice for all necessary Controlled Thermonuclear Research (CTR) applications. The types of capacitors required for the various CTR operating conditions are enumerated. Factors that influence the life, cost and operating abilities of these types of capacitors are discussed. The problems of capacitors in a radiation environment are considered. Areas are defined where future research is needed. Some directions that this research should take are suggested

Studies on energy gain of muon catalyzed hybrid D-D Reactor and it comparison to D-T system

International Nuclear Information System (INIS)

Eskandari, M.R.; Hoseine-Motlagh, S.N.; Faghihi, F.

1998-01-01

Regarding the advantages of hybrid fusion reactors, in most recent studies, the energy gain of muon catalyzed D-T hybrid reactors are studied. Knowing advantages of D-D fuel such as availability, not being radio-active, no tritium inventory requirement and transport problems, the muon catalyzed hybrid D-D reactor (μCHDDR) gain is calculated here for a given net reaction by solving its dynamical equations for various deuterium densities. It is shown theμCHDDR has advantages even for previously suggested similar D-T reactor

Thermonuclear investigation development

International Nuclear Information System (INIS)

Pistunovich, V.I.; Solov'ev, N.S.

1975-01-01

The patent situation, based mainly on a study of the situations of Great Britain, USA, France, Federal Republic of Germany and Japan from 1958 to 1974 is reviewed. Applicants have obtained around 300 patents on equipment for control of thermonuclear reactions. In the second half some decrease in the introduction of patents on high-temperature-plasma studies is noted. Multipole magnet systems for holding plasma and toroidal equipment of the takamak type have been developed recently. In the 70s, patents were published on the use of high-energy electrons for stabilization and heating of plasma in toroidal stationary systems. Starting with the mid 60s, considerable attention has been given to heating of plasma with laser radiation and to conversion of thermonuclear energy to electrical. There are 20 domestic patents on laser heating of plasma, and 75 and 45 domestic patents, respectively, on open and composite traps and 120 and 40 such patents abroad. While in the 60s equipment of different types was patented in many directions, part of which has not found further use, today work abroad is being patented basically on laser heating of plasma, toroidal magnetic systems, ion beam interference, and plasma bunching

Inertia thermonuclear device

International Nuclear Information System (INIS)

Madarame, Haruki; Nakamura, Norio; Oomura, Hiroshi.

1983-01-01

Purpose: To enable effective recovery of the thermonuclear reaction energy and effective protection of a cylinder metal against thermal destruction by forming a uniform and stable liquid metal wall to the inside of a cylindrical member. Constitution: Cylindrical body having a lateral axis is rotatably supported so that a liquid metal wall for use in the wet wall type thermonuclear device is formed centrifugally. A liquid metal injection port for injecting the liquid metal to the cylindrical member is disposed to the lateral axis and a liquid metal exit for flowing out the injected liquid metal is disposed to the body of the cylindrical member, so as to form a moving liquid metal layer flowing from the injection port through the inner circumferential surface of the cylindrical member to the liquid metal exit port. Then, the liquid metal is centrifugally forced to the inner surface of the cylindrical body to form a uniform and stable liquid metal wall at the inner surface of the cylindrical body, whereby the reaction energy can effectively be recovered and the cylinder metal can effectively be protected against thermal destruction. (Yoshihara, H.)

Localized thermonuclear runaways and volcanoes on degenerate dwarf stars

Energy Technology Data Exchange (ETDEWEB)

Shara, M.M.

1982-10-15

Practically all studies to date of thermonuclear runaways on degenerate dwarf stars in binary systems have considered only spherically symmetric eruptions. We emphasize that even slightly non-spherically symmetric accretion leads to transverse temperature gradients in the dwarfs' accreted envelopes. Over a rather broad range of parameter space, thermalization time scales in accreted envelopes are much longer than thermonuclear runaway time scales. Thus localized thermonuclear runaways (i.e., runaways much smaller than the host degenerate star) rather than spherically symmetric global eruptions are likely to occur on many degenerate dwarfs. Localized runaways are more likely to occur on more massive and/or hotter dwarfs.

Nuclear Physics Constraints on the Characteristics of Astrophysical Thermonuclear Flashes

International Nuclear Information System (INIS)

Truran, James W

2012-01-01

We review the nuclear physics that is associated with the outbursts of Type Ia (thermonuclear) supernova explosions and with the thermonuclear runaway events that define the outbursts of both classical novae and recurrent novae. We describe how distinguishing characteristics of these two classes of astrophysical explosion are strongly dependent both upon fuel ignition in degenerate matter and upon the rates of critical charged-particle reaction rates and weak interaction rates. In this centennial celebration of the important contributions of Rutherford and his collaborators to our understanding of the structure of the nucleus of an atom, it is quite interesting to note the evolution of the α-particle scattering experiments described in Rutherford's seminal paper (Rutherford 1911) to current studies of α-particle induced reactions and their defining roles in studies of stellar, nova, and supernova nucleosynthesis. We identify and discuss for example: (1) the manner in which (α, p) reactions in proximity to the Z = N line carry the major flows from 12 C and 16 O to 56 Ni in Type Ia supernovae; and (2) the critical role of the 15 O(α, γ) 19 Ne reaction in possibly effecting 'breakout' of the Hot CNO cycles at the highest temperatures achievable in Classical Novae. In this contribution, we first review the current status our understanding of Type Ia supernova events and then that of Classical Novae.

The international thermonuclear reactor project

International Nuclear Information System (INIS)

James, T.R.

1993-01-01

The International Thermonuclear Experimental Reactor Project is a 6-year collaborative effort involving the U.S., Europe, Japan, and the Russian Federation to produce a detailed engineering design for the next-step fusion device

Merging white dwarfs and thermonuclear supernovae.

Science.gov (United States)

van Kerkwijk, M H

2013-06-13

Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure and the disintegration of the whole white dwarf. It is usually thought that fusion is reignited in near-pycnonuclear conditions when the white dwarf approaches the Chandrasekhar mass. I briefly describe two long-standing problems faced by this scenario, and the suggestion that these supernovae instead result from mergers of carbon-oxygen white dwarfs, including those that produce sub-Chandrasekhar-mass remnants. I then turn to possible observational tests, in particular, those that test the absence or presence of electron captures during the burning.

Safety and economic comparison of fusion fuel cycles

International Nuclear Information System (INIS)

Brereton, S.J.; Kazimi, M.S.

1987-08-01

The DT, DD and DHe fusion fuel cycles are compared on the basis of safety and economics. The designs for the comparison employ HT-9 structure and helium coolant; liquid lithium is used as the tritium breeder for the DT fuel cycle. The reactors are pulsed superconducting tokamaks, producing 4000 MW thermal power. The DT and DD designs are developed utilizing a plasma beta of 5%, 10% and 20%, assuming first stability scaling laws; a single value of 10% for beta is used for the DHe design. Modest extrapolations of current day technology are employed, providing a reference point for the relative ranking of the fuel cycles. Technological advances and improved understanding of the physics involved may alter the relative positions from what has been determined here. 92 figs., 59 tabs

Radiation shielding for TFTR DT diagnostics

International Nuclear Information System (INIS)

Ku, L.P.; Johnson, D.W.; Liew, S.L.

1994-01-01

The authors illustrate the designs of radiation shielding for the TFTR DT diagnostics using the ACX and TVTS systems as specific examples. The main emphasis here is on the radiation transport analyses carried out in support of the designs. Initial results from the DT operation indicate that the diagnostics have been functioning as anticipated and the shielding designs are satisfactory. The experience accumulated in the shielding design for the TFTR DT diagnostics should be useful and applicable to future devices, such as TPX and ITER, where many similar diagnostic systems are expected to be used

Thermonuclear astrophysics

International Nuclear Information System (INIS)

Clayton, D.D.; Woosley, S.E.

1974-01-01

We discuss the types of thermonuclear reactions that are of importance to stellar evolution and nucleosynthesis, with particular attention to the explosive ejection of shells of He, C, O, and Si. We present tables of the reactions important in the various burning phases, including the reason for their importance and an estimate of the value of a carefully measured rate. This format is chosen for dual purpose: (1) to clarify the nuclear needs by evaluating the importance of specific reactions within the astronomical settings and (2) by assigning a value scale for cross-section measurements

Isotope effect on confinement in DT plasmas

International Nuclear Information System (INIS)

Fukuyama, A.; Itoh, K.; Itoh, S.; Yagi, M.; Azumi, M.

1994-03-01

Isotope effect on the energy confinement time is discussed for the DT plasma. The transport theory which is based on the ballooning mode turbulence is applied. When the DT plasma is produced under the condition of β p >1, the energy confinement time of DT plasma (50% mixture) is expected to be about 1.2 times better than the D plasma with the same operation condition. (author)

Nuclear microexplosion futurology

International Nuclear Information System (INIS)

Winterberg, F.

1978-01-01

Unlike magnetic confinement fusion which is restricted to the DT thermonuclear reaction, inertial confinement fusion should also be feasible with the DD and perhaps the HB 11 thermonuclear reaction. The ignition energies for the DD and HB 11 reactions though, are much larger than for the DT reaction. Four approaches to ignite the DD and HB 11 reactions are proposed and which are: 1. magnetically insulated multi-stage pulse power driven GeV particle accelerators; 2. bunching of space charge neutralized MeV ion beams; 3. staged microexplosion targets; and 4. autocatalytic thermonuclear detonation waves. The ignition of the HB 11 thermonuclear reaction would make subrelavistic (approximately1/10 velocity of light) interstellar space flight a distant but definite possibility. (orig.) [de

Progress towards a high-gain and robust target design for heavy ion fusion

Energy Technology Data Exchange (ETDEWEB)

Henestroza, Enrique; Grant Logan, B. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2012-07-15

Recently [E. Henestroza et al., Phys. Plasmas 18, 032702 (2011)], a new inertial-fusion target configuration, the X-target, using one-sided axial illumination has been explored. This class of target uses annular and solid-profile heavy ion beams to compress and ignite deuterium-tritium (DT) fuel that fills the interior of metal cases that have side-view cross sections in the shape of an 'X.' X-targets using all-DT-filled metal cases imploded by three annular ion beams resulted in fuel densities of {approx}50 g/cm{sup 3} at peak compression, and fusion gains of {approx}50, comparable to heavy ion driven hohlraum targets [D. A. Callahan-Miller and M. Tabak, Phys. Plasmas 7, 2083 (2000)]. This paper discusses updated X-target configurations that incorporate inside the case a propellant (plastic) and a pusher (aluminum) surrounding the DT fuel. The updated configurations are capable of assembling higher fuel areal densities {approx}2 g/cm{sup 2} using two annular beams to implode the target to peak DT densities {approx}100 g/cm{sup 3}, followed by a fast-ignition solid ion beam which heats the high-density fuel to thermonuclear temperatures in {approx}200 ps to start the burn propagation, obtaining gains of {approx}300. These targets have been modeled using the radiation-hydrodynamics code HYDRA [M. M. Marinak et al., Phys. Plasmas 8, 2275 (2001)] in two- and three- dimensions to study the properties of the implosion as well as the ignition and burn propagation phases. At typical Eulerian mesh resolutions of a few microns, the aluminum-DT interface shows negligible Rayleigh-Taylor (RT) and Richtmyer-Meshkov instability growth; also, the shear flow of the DT fuel as it slides along the metal X-target walls, which drives the RT and Kelvin Helmholtz instabilities, does not have a major effect on the burning rate. An analytic estimate of the RT instability process at the Al-DT interface shows that the aluminum spikes generated during the pusher deceleration phase

Towards upper power levels: thermonuclear fusion

International Nuclear Information System (INIS)

Vedel, Jean

1983-01-01

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

Report on impact fusion workshop, LASL, July 1979

International Nuclear Information System (INIS)

Russell, F.M.

1979-12-01

The concept of power production from thermonuclear fusion caused by inertial confinement of D,T fuel was examined from the standpoints of overall scientific feasibility and present state-of-art in the technologies involved. No defect in principle was found but much R and D work is needed in all aspects and especially that of accelerator devices. So far only one intrinsically stable macro-particle accelerator has been proposed, based on the mixed-μ concept of stability. (author)

Calculations of the Auger deexcitation rate of the dtμ within the muonic quasi-molecule, [(dtμ)dee

International Nuclear Information System (INIS)

Armour, E.A.G.; Lewis, D.M.; Hara, S.

1993-01-01

A key process in muon catalysed fusion is the deexcitation of the dtμ within the resonant muonic quasi-molecule [(dtμ)dee], by emission of an Auger electron. The dtμ in the quasi-molecule is initially in a weakly bound excited state with J = 1 and v = 1. In this paper, calculations taking full account of the molecular nature of the quasi-molecule are carried out of the rate of the dominant deexcitation to the state with J = 0 and v = 1. (orig.)

Temperature measurements in thermonuclear plasmas

International Nuclear Information System (INIS)

Breton, D.

1958-01-01

The temperatures needed to produce thermonuclear reactions are of the order of several million degrees Kelvin. Devising methods for measuring such temperatures has been the subject of research in many countries. In order to present the problem clearly and to demonstrate its importance, the author reviews the various conditions which must be fulfilled in order that reactions may be qualified as thermonuclear. The relationship between the temperature and the cross-section of the reactions is studied, and it is shown that the notion of temperature in the plasmas is complex, which leads to a consideration of the temperature of the ions and that of the electrons. None of the methods for the temperature measurements is completely satisfactory because of the hypotheses which must be made, and which are seldom fulfilled during high-intensity discharges in the plasmas. In practice it is necessary to use several methods simultaneously. (author) [fr

Compound light ion fuel cycles: An approach to optimization

International Nuclear Information System (INIS)

Kernbichler, W.; Heindler, M.

1985-01-01

Together with the relatively high complexity and the low power density anticipated for fusion reactors have produced different attitude towards the long term perspective of fusion as a commercial energy source. The favourite pathway is to trust in optimization aiming at low tritium inventory, the availability of low-activation structure materials, the increase of redundancy, etc. In contrast, a respectable minority suggests turning away from d-t fusion or to envisage fusion as powerful neutron rather than energy source (fusion as fissile fuel or synfuel factory). We here intend to investigate the potentiality of fusion based on alternatives to d-t fuel. Such so called ''advanced fuels'' require higher burn temperatures and advanced reactor concepts (high-beta confinement schemes to compensate for their inherently lower reactivities. The experience that has been gained in fusion oriented plasma research admittedly justifies optimism for advanced fuels to a still lesser extent than for d-t. It can however be argued that it may pay off to choose a developmental direction with higher risk for failure but aiming at a more desirable end product. In order to explore this eventual desirability of advanced fuel fusion, we assume, as has been done in the case of d-t, that the first category of problems can be successfully handled. Our goal is thus to examine the potentiality of advanced fuels with respect to the second category of problems which largely determines the attractivity of utilization in fusion reactors

Tritium Aspects of Fueling and Exhaust Pumping in Magnetic Fusion Energy

Energy Technology Data Exchange (ETDEWEB)

Baylor, Larry R. [ORNL; Meitner, Steven J. [ORNL

2017-04-01

Magnetically confined fusion plasmas generate energy from deuterium-tritium (DT) fusion reactions that produce energetic 3.5 MeV alpha particles and 14 MeV neutrons. Since the DT fusion reaction rate is a strong function of plasma density, an efficient fueling source is needed to maintain high plasma density in such systems. Energetic ions in fusion plasmas are able to escape the confining magnetic fields at a much higher rate than the fusion reactions occur, thus dictating the fueling rate needed. These lost ions become neutralized and need to be pumped away as exhaust gas to be reinjected into the plasma as fuel atoms.The technology to fuel and pump fusion plasmas has to be inherently compatible with the tritium fuel. An ideal holistic solution would couple the pumping and fueling such that the pump exhaust is directly fed back into pellet formation without including impurity gases. This would greatly reduce the processing needs for the exhaust. Concepts to accomplish this are discussed along with the fueling and pumping needs for a DT fusion reactor.

Gungula, DT

African Journals Online (AJOL)

Gungula, DT. Vol 13, No 3 (2007) - Articles The effects of nitrogen rates on phenology and yield components of early maturing maize cultivars. Abstract. ISSN: 1118-0579. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms ...

Thermonuclear reaction rates. III

International Nuclear Information System (INIS)

Harris, M.J.; Fowler, W.A.; Caughlan, G.R.; Zimmerman, B.A.

1983-01-01

Stellar thermonuclear reaction rates are revised and updated, adding a number of new important reaction rates. Several reactions with large negative Q-values are included, and examples of them are discussed. The importance of the decay rates for Mg-26(p,n) exp 26 Al and Al-26(n,p) exp 26 Mg for stellar studies is emphasized. 19 references

Resonant thermonuclear reaction rate

International Nuclear Information System (INIS)

Haubold, H.J.; Mathai, A.M.

1986-01-01

Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms

Magnetohydrodynamics and the thermonuclear problem

Energy Technology Data Exchange (ETDEWEB)

Alfven, H [Department of Electronics, Royal Institute of Technology, Stockholm (Sweden)

1958-07-01

The importance of magnetohydrodynamics and plasma physics for the solution of thermonuclear problem is presented in the paper. Methods for capture of a plasma by a magnetic field are discussed. From the study it is concluded that in principle it is possible to shoot heated plasma into a magnetic field and capture it there. A possible method of capturing plasma which is shot into a magnetic field is illustrated. Magnetohydrodynamic research performed during the last decade in Stockholm is presented. Following a long series of investigations of relatively cool plasmas, it has been started a series of experimental investigations on hot plasmas, concentrating on the fundamental properties of the plasma. New ways of the approach to the thermonuclear problem are analysed. Experiments have been with discharges of a few hundred kiloamps to produce fast-moving magnetized plasmas, in order to investigate whether they could be captured by magnetic fields in the discussed way.

Thermonuclear controlled fusion: international cooperation

International Nuclear Information System (INIS)

Conscience, J.-F.

2001-01-01

This report summarizes the current worldwide status of research in the field of thermonuclear controlled fusion as well as the international research programme planed for the next decades. The two main projects will be the ITER facility (International Thermonuclear Experimental Reactor) that should produce 10 times more energy than the energy injected, and the IFMIF (International Fusion Materials Irradiation Facility) designed to study the reactions of materials under intense neutron fluxes. The future of the pioneering JET facility (Joint European Torus) is also discussed. The engagement of the various countries (USA, Japan, Germany, Russian Federation and Canada) and international organisations (EURATOM and IEA) in terms of investment and research is described. Switzerland is involved in this program through an agreement with EURATOM and is mainly dedicated to experimental studies with the TCV machine in Lausanne and numerical studies of plasma configurations. It will participate to the development of the microwave plasma heating system for the ITER machine

Thermonuclear device

International Nuclear Information System (INIS)

Inoue, Toyokazu; Murata, Toru.

1983-01-01

Purpose: To shield superconducting coils for use in the generation of magnetic field against neutron irradiation thereby preventing tritium contamination. Constitution: The thermonuclear device comprises, in its inside, a vacuum container for containing plasmas, superconducting coils disposed to the outside of the vacuum container and neutron absorbers disposed between the super-conducting coils and the vacuum container. since neutrons issued from the plasma are absorbed by neutron absorbers and not irradiated to the superconducting coils, generation of tritium due to the reaction between 3 He in the liquid helium as the coolants for the super-conducting coils and the neutrons is prevented. (Aizawa, K.)

Introduction to the physics of ICF capsules

International Nuclear Information System (INIS)

Lindl, J.D.

1989-01-01

Inertial Confinement Fusion is an approach to fusion which relies on the inertia of the fuel mass to provide confinement. To achieve conditions under which this confinement is sufficient for efficient thermonuclear burn, high gain ICF targets designed to be imploded directly by laser light. These capsules are generally a spherical shell which is filled with low density DT gas. The shell is composed of an outer region which forms the ablator and an inner region of frozen or liquid DT which forms the main fuel. Energy from the driver is delivered to the ablator which heats up and expands. As the ablator expands and blows outward, the rest of the shell is forced inward to conserve momentum. In this implosion process, several features are important. We define the in-flight-aspect-ratio (IFAR) as the ratio of the shell radius R as it implodes to its thickness ΔR. Hydrodynamic instabilities during the implosion impose limits on this ratio which results in a minimum pressure requirement of about 100 Mbar. The convergence ratio is defined as the ratio of the initial outer radius of the ablator to the final compressed radius of the hot spot. This hot spot is the central region of the compressed fuel which is required to ignite the main fuel in high gain designs. Typical convergence ratios are 30--40. To maintain a nearly spherical shape during the implosion, when convergence ratios are this large, the flux delivered to the capsule must be uniform to a few percent. The remainder of this paper discusses the conditions necessary to achieve thermonuclear ignition in these ICF capsules

Thermonuclear Bursts with Short Recurrence Times from Neutron Stars Explained by Opacity-driven Convection

Energy Technology Data Exchange (ETDEWEB)

Keek, L. [X-ray Astrophysics Laboratory, Astrophysics Science Division, NASA/GSFC, Greenbelt, MD 20771 (United States); Heger, A., E-mail: laurens.keek@nasa.gov [Monash Center for Astrophysics, School of Physics and Astronomy, Monash University, Victoria, 3800 (Australia)

2017-06-20

Thermonuclear flashes of hydrogen and helium accreted onto neutron stars produce the frequently observed Type I X-ray bursts. It is the current paradigm that almost all material burns in a burst, after which it takes hours to accumulate fresh fuel for the next burst. In rare cases, however, bursts are observed with recurrence times as short as minutes. We present the first one-dimensional multi-zone simulations that reproduce this phenomenon. Bursts that ignite in a relatively hot neutron star envelope leave a substantial fraction of the fuel unburned at shallow depths. In the wake of the burst, convective mixing events driven by opacity bring this fuel down to the ignition depth on the observed timescale of minutes. There, unburned hydrogen mixes with the metal-rich ashes, igniting to produce a subsequent burst. We find burst pairs and triplets, similar to the observed instances. Our simulations reproduce the observed fraction of bursts with short waiting times of ∼30%, and demonstrate that short recurrence time bursts are typically less bright and of shorter duration.

Isochoric heating of DT fuels through PW-laser-produced proton beams

International Nuclear Information System (INIS)

Maynard, G.; Barriga-Carrasco, M.D.

2005-01-01

Laser Proton Source (LPS) can generate short bunch of energetic protons with a nearly zero initial emittance. It is thus expected that LPS can deposit a very high density of energy inside dense matter, in particular, in the context of fast ignition of an inertial fusion target. We investigate here one of the factors that can limit the density of deposited energy. It concerns the transverse diffusion, occurring during the transport between the LPS and DT. As the rear surface of LPS should be efficiently protected, the proton along its path has to interact with a substantial amount of high-Z material. Therefore the induced transverse dispersion can become significant. The transport of the proton beam inside a plasma target is calculated using a numerical code, which main features are presented

Isochoric heating of DT fuels through PW-laser-produced proton beams

Energy Technology Data Exchange (ETDEWEB)

Maynard, G. [Laboratoire de Physique des Gaz et des Pasmas, CNRS UMR8578, bat. 210, Universite Paris XI, F-91405, Orsay (France)]. E-mail: gilles.maynard@pgp.u-psud.fr; Barriga-Carrasco, M.D. [Laboratoire de Physique des Gaz et des Pasmas, CNRS UMR8578, bat. 210, Universite Paris XI, F-91405, Orsay (France)

2005-05-21

Laser Proton Source (LPS) can generate short bunch of energetic protons with a nearly zero initial emittance. It is thus expected that LPS can deposit a very high density of energy inside dense matter, in particular, in the context of fast ignition of an inertial fusion target. We investigate here one of the factors that can limit the density of deposited energy. It concerns the transverse diffusion, occurring during the transport between the LPS and DT. As the rear surface of LPS should be efficiently protected, the proton along its path has to interact with a substantial amount of high-Z material. Therefore the induced transverse dispersion can become significant. The transport of the proton beam inside a plasma target is calculated using a numerical code, which main features are presented.

Sticking in muon catalyzed D-T fusion

International Nuclear Information System (INIS)

Petitjean, C.; Sherman, R.H.; Bossy, H.; Daniel, H.; Hartmann, F.J.; Neumann, W.; Schmidt, G.; Egidy, T. von

1986-10-01

The issue of μα sticking after muon catalyzed DT fusion is controversial, since a number of theoretical and experimental results came out recently with sticking values ω s varying over a large range. After a review of this situation, our measurements at SIN and methods of sticking analysis from neutron time structures are presented in detail. The important point is the correct understanding of the experimentally observed time distributions. At high density (liquid DT) we find, after correction for other fusion channels, for DT sticking ω s (0.45 +- 0.05)%, not dependent on tritium concentration c t and in accordance with our X-ray observations. At low density (DT gas, φ 3% - 8%) our preliminary result is 0.50 +- 0.10%, giving a ratio 1.1 +- 0.2 in agreement with conventional theories, but strongly disagreeing with the LAMPF experiment of S.E. Jones et al. Our result sets the maximum fusion output per muon to less than 220 +- 20. (author)

Characterizing the Degree of Fuel Magnetization for MagLIF Using Neutron Diagnostics

Science.gov (United States)

Hahn, K. D.; Chandler, G. A.; Schmit, P. F.; Knapp, P. F.; Hansen, S. B.; Harding, E.; Ruiz, C. L.; Jones, B.; Gomez, M. R.; Ampleford, D. J.; Torres, J. A.; Alberto, P. J.; Cooper, G. W.; Styron, J. D.

2017-10-01

We are studying Magnetized Liner Inertial Fusion sources which utilize deuterium fuel and produce up to 4e12 primary DD and 5e10 secondary DT neutrons. For this concept, magnetizing the fuel can relax the stagnation pressures and densities required for ignition by insulating the hot fuel and confining the charged fusion products. The degree of magnetization of the fuel at stagnation is quantified using secondary DT neutron spectral measurements in the axial and radial directions and is also related to the ratio of the secondary DT yield to the primary DD yield. Measurements have confirmed that charged fusion products are strongly magnetized, as indicated by the product of the magnetic field and the fuel radius, to 0.4 MG-cm. We present new results that compare the degree of fuel magnetization inferred from spectral and yield measurements. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.

Reactor wall in thermonuclear device

International Nuclear Information System (INIS)

Shibui, Masanao.

1988-01-01

Purpose: To always monitor the life of armours in reactor walls and automatically shutdown the reactor if it should be operated in excess of the limit of use. Constitution: Monitoring material of lower melting point than armours (for example beryllium pellets) as one of the reactor wall constituents of a thermonuclear device are embedded in a region leaving the thickness corresponding to the allowable abrasion of the armour. In this structure, if the armours are abrased due to particle loads of a plasma and the abrasion exceeds a predetermined allowable level, the monitoring material is exposed to the plasma and melted and evaporated. Since this can be detected by impurity monitors disposed in the reactor, it is possible to recognize the limit for the working life of the armours. If the thermonuclear reactor should be operated accidentally exceeding the life of the armours, since a great amount of the monitoring materials have been evaporated, they flow into the plasma to increase the plasma radiation loss thereby automatically eliminate the plasma. (K.M.)

Method of producing encapsulated thermonuclear fuel particles

International Nuclear Information System (INIS)

Smith, W.H.; Taylor, W.L.; Turner, H.L.

1976-01-01

A method of producing a fuel particle is disclosed, which comprises forming hollow spheroids which have a mass number greater than 50, immersing said spheroids while under the presence of pressure and heat in a gaseous atmosphere containing an isotope, such as deuterium and tritium, so as to diffuse the gas into the spheroid and thereafter cooling said spheroids up to about 77 0 Kelvin to about 4 0 Kelvin. 4 Claims, 3 Drawing Figures

ICF with momentum-rich beams

Energy Technology Data Exchange (ETDEWEB)

Maschke, A.W.

1982-10-01

A novel approach to obtain thermonuclear ignitions condition is suggested. Utilizing state-of-the-art ion source brightness parameters, and high gradient acceleration columns, it is possible to focus 10 kJ of heavy ions to a few mm spot, using a 1-meter radius spherical ion source. Heavy ion energies of 500 to 1000 keV have the velocity required for volume ignition of DT. The beam mass is typically 10 times greater than that of the DT which is to be burned. A spherical array of ion sources is envisioned, using time-of-flight bunching to achieve the required power density at the central focus. Beam space charge neutralization is assumed to take place in a background plasma. The DT, originally a few mm gas ball, is compressed and heated by the direct transfer of the beam energy to the fuel. The necessary inward mementum is produced directly by the accelerator, not by ablation.

ICF with momentum-rich beams

International Nuclear Information System (INIS)

Maschke, A.W.

1982-01-01

A novel approach to obtain thermonuclear ignitions condition is suggested. Utilizing state-of-the-art ion source brightness parameters, and high gradient acceleration columns, it is possible to focus 10 kJ of heavy ions to a few mm spot, using a 1-meter radius spherical ion source. Heavy ion energies of 500 to 1000 keV have the velocity required for volume ignition of DT. The beam mass is typically 10 times greater than that of the DT which is to be burned. A spherical array of ion sources is envisioned, using time-of-flight bunching to achieve the required power density at the central focus. Beam space charge neutralization is assumed to take place in a background plasma. The DT, originally a few mm gas ball, is compressed and heated by the direct transfer of the beam energy to the fuel. The necessary inward mementum is produced directly by the accelerator, not by ablation

Laser thermonuclear fusion with force confinement of hot plasma

International Nuclear Information System (INIS)

Korobkin, V.V.; Romanovsky, M.Y.

1994-01-01

The possibility of the utilization of laser radiation for plasma heating up to thermonuclear temperatures with its simultaneous confinement by ponderomotive force is investigated. The plasma is located inside a powerful laser beam with a tubelike section or inside a cavity of duct section, formed by several intersecting beams focused by cylindrical lenses. The impact of various physical processes upon plasma confinement is studied and the criteria of plasma confinement and maintaining of plasma temperature are derived. Plasma and laser beam stability is considered. Estimates of laser radiation energy necessary for thermonuclear fusion are presented

MR safety: simultaneous B0, dΦ/dt, and dB/dt measurements on MR-workers up to 7 T.

Science.gov (United States)

Groebner, Jens; Umathum, Reiner; Bock, Michael; Krafft, Axel J; Semmler, Wolfhard; Rauschenberg, Jaane

2011-12-01

The EU directive on safety requirements (2004/40/EC) limits the exposure to time varying magnetic fields to dB /dt=200 mT/s. This action value is not clearly defined as it considers only the temporal change of the magnitude of B. Thus, only the translational motion in the magnet's fringe field is considered and rotations are neglected. A magnetic field probe was constructed to simultaneously record the magnetic flux density B(x, y, z) with a 3-axis Hall sensor and the induced voltage due to movements with a set of three orthogonal coils. Voltages were converted into time-varying magnetic flux d Φ(x, y, z)/dt serving as an exposition parameter for both translations and rotations. To separate the two types of motion, d B/dt was additionally calculated on the basis of the Hall sensor's data. The calibrated probe was attached to the forehead of 8 healthcare workers and 17 MR physicists, and B and dΦ/dt were recorded during standard operating procedures at three different MR systems up to 7 T. The maximum percentage of the translational motion referring the data including both translations and rotations amounts to 32%. During volunteer measurements, maximum exposure values of dΦ/dt=21 mWb/s, dB/dt=1.40 T/s and |B|=2.75 T were found. The findings in this work indicate that both translations and rotations in the vicinity of an MR system should be taken into account, and that a single regulatory action level might not be sufficient.

Thermonuclear device

International Nuclear Information System (INIS)

Tezuka, Masaru.

1993-01-01

Protrusions and recesses are formed to a vacuum vessel and toroidal magnetic coils, and they are engaged. Since the vacuum vessel is generally supported firmly by a rack or the like by support legs, the toroidal magnetic field coils can be certainly supported against tumbling force. Then, there can be attained strong supports for the toroidal magnetic field coils, in addition to support by wedges on the side of inboard and support by share panels on the side of outboard, capable of withstanding great electromagnetic forces which may occur in large-scaled next-generation devices. That is, toroidal magnetic field coils excellent from a view point of deformation and stress can be obtained, to provide a thermonuclear device of higher reliability. (N.H.)

A Game Theoretic Model of Thermonuclear Cyberwar

Energy Technology Data Exchange (ETDEWEB)

Soper, Braden C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-08-23

In this paper we propose a formal game theoretic model of thermonuclear cyberwar based on ideas found in [1] and [2]. Our intention is that such a game will act as a first step toward building more complete formal models of Cross-Domain Deterrence (CDD). We believe the proposed thermonuclear cyberwar game is an ideal place to start on such an endeavor because the game can be fashioned in a way that is closely related to the classical models of nuclear deterrence [4–6], but with obvious modifications that will help to elucidate the complexities introduced by a second domain. We start with the classical bimatrix nuclear deterrence game based on the game of chicken, but introduce uncertainty via a left-of-launch cyber capability that one or both players may possess.

Alpha particle loss in the TFTR DT experiments

International Nuclear Information System (INIS)

Zweben, S.J.; Darrow, D.S.; Herrmann, H.W.

1995-01-01

Alpha particle loss was measured during the TFTR DT experiments using a scintillator detector located at the vessel bottom in the ion grad-B drift direction. The DT alpha particle loss to this detector was consistent with the calculated first-orbit loss over the whole range of plasma current I=0.6-2.7 MA. In particular, the alpha particle loss rate per DT neutron did not increase significantly with fusion power up to 10.7 MW, indicating the absence of any new ''collective'' alpha particle loss processes in these experiments

Application of controlled thermonuclear reactor fusion energy for food production

International Nuclear Information System (INIS)

Dang, V.D.; Steinberg, M.

1975-06-01

Food and energy shortages in many parts of the world in the past two years raise an immediate need for the evaluation of energy input in food production. The present paper investigates systematically (1) the energy requirement for food production, and (2) the provision of controlled thermonuclear fusion energy for major energy intensive sectors of food manufacturing. Among all the items of energy input to the ''food industry,'' fertilizers, water for irrigation, food processing industries, such as beet sugar refinery and dough making and single cell protein manufacturing, have been chosen for study in detail. A controlled thermonuclear power reactor was used to provide electrical and thermal energy for all these processes. Conceptual design of the application of controlled thermonuclear power, water and air for methanol and ammonia synthesis and single cell protein production is presented. Economic analysis shows that these processes can be competitive. (auth)

The ''Dolphin'' power laser installation for spherical thermonuclear target heating

International Nuclear Information System (INIS)

Basov, N.G.; Bykovskij, N.E.; Danilov, A.E.

1978-01-01

12-channel laser installation the ''Dolphin'' for thermonuclear target heating in the radiation spheric geometry has been developed to carry out series of physical investigations of laser-thermonuclear plasma system, optimization of target heating conditions and obtaining a comparatively large value of thermonuclear output in ratio to the energy of absorbed light radiation in the target. The description of installation main elements, consisting of the following components, is given: 1)neodymium laser with the maximum permissible radiation energy of 10kJ, with light pulse duration of 10 -10 /10 -9 c and radiation divergence of approximately 5x10 -4 rad; 2)vacuum chamber, where laser radiation interaction with plasma takes place; 3)diagnostic means of laser and plasma parameters and 4)focus system. The focus system provides a high degree of target spherical radiation symmetry at current maximum density on its surface of approximately 10 15 W/cm 2

Progress Towards Ignition on the National Ignition Facility

Science.gov (United States)

Edwards, John

2012-10-01

Since completion of the National Ignition Facility (NIF) construction project in March 2009, a wide variety of diagnostics, facility infrastructure, and experimental platforms have been commissioned in pursuit of generating the conditions necessary to reach thermonuclear ignition in the laboratory via the inertial confinement approach. NIF's capabilities and infrastructure include over 50 X-ray, optical, and nuclear diagnostics systems and the ability to shoot cryogenic DT layered capsules. There are two main approaches to ICF: direct drive in which laser light impinges directly on a capsule containing a solid layer of DT fuel, and indirect drive in which the laser light is first converted to thermal X-rays. To date NIF has been conducting experiments using the indirect drive approach, injecting up to 1.8MJ of ultraviolet light (0.35 micron) into 1 cm scale cylindrical gold or gold-coated uranium, gas-filled hohlraums, to implode 1mm radius plastic capsules containing solid DT fuel layers. In order to achieve ignition conditions the implosion must be precisely controlled. The National Ignition Campaign (NIC), an international effort with the goal of demonstrating thermonuclear burn in the laboratory, is making steady progress toward this. Utilizing precision pulse-shaping experiments in early 2012 the NIC achieve fuel rhoR of approximately 1.2 gm/cm^2 with densities of around 600-800 g/cm^3 along with neutron yields within about a factor of 5 necessary to enter a regime in which alpha particle heating will become important. To achieve these results, experimental platforms were developed to carefully control key attributes of the implosion. This talk will review NIF's capabilities and the progress toward ignition, as well as the physics of ignition targets on NIF and on other facilities. Acknowledgement: this work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

MUON DETECTORS: DT

CERN Multimedia

C. Fernandez Bedoya and M. Dallavalle

2010-01-01

The DT system operation since the 2010 LHC start up is remarkably smooth.
 All parts of the system have behaved very satisfactorily in the last two months of operation with LHC pp collisions. Disconnected HV channels remain at the level of 0.1%, and the loss in detector acceptance because of failures in the readout and Trigger electronics is about 0.4%. The DT DCS-LHC handshake mechanism, which was strengthened after the short 2009 LHC run, operates without major problems. A problem arose with the opto-receivers of the trigger links connecting the detector to USC; the receivers would unlock from transmission for specific frequencies of the LHC lock, in particular during the LHC ramp. For relocking the TX and RX a “re-synch” command had to be issued. The source of the problem has been isolated and cured in the Opto-RX boards and now the system is stable. The Theta trigger chain also has been commissioned and put in operation. Several interventions on the system have been made, pro...

MUON DETECTORS: DT

CERN Document Server

M. Dallavalle.

The DT system is ready for the LHC start up. The status of detector hardware, control and safety, of the software for calibration and monitoring and of people has been reviewed at several meetings, starting with the CMS Action Matrix Review and with the Muon Barrel Workshop (October 5 to 7). The disconnected HV channels are at a level of about 0.1%. The loss in detector acceptance because of failures in the Read-Out and Trigger electronics is about 0.5%. The electronics failure rate has been lower this year: next year will tell us whether the rate has stabilised and hopefully will confirm that the number of spares is adequate for ten years operation. Although the detector safety control is very accurate and robust, incidents have happened. In particular the DT system suffered from a significant water leak, originated in the top part of YE+1, that generated HV trips in eighteen chambers going transversely down from the top sector in YB+2 to the bottom sector in YB-2. All chambers recovered and all t...

MUON DETECTORS: DT

CERN Multimedia

Marco Dallavalle

The April Muon Barrel Workshop marked the boundary between DT maintenance work and preparation for the LHC run. The thrust of the DT group was then directed, on one side, towards system safety and reliability, and, on the other side, towards enlarging the pool of experts and shifters. Analysis of the 2008 CRAFT data has provided details on the performance and a first set of calibration constants. Improvements to the safety system (both DSS and DCS) have been made: flow-meters inserted in the cooling system provide on-line information; an interlock signal is available from the gas racks; electronics racks have thermostats and fire detection systems; power to the mini-crates is cut when DCS communication is lost. Water leak detection cables were installed on the wheels: they provide an early warning before the HV trips and help in localizing the leak. On April 28, a short circuit in an opto-receiver board recently installed and cabled in USC caused a minor rack fire. This was satisfactorily mastered by the DS...

The scientific case for a JET D-T experiment

International Nuclear Information System (INIS)

Weisen, H.; Sips, A. C. C.; Horton, L. D.; Challis, C. D.; Sharapov, S. E.; Zastrow, K.-D.; Eriksson, L.-G.; Batistoni, P.

2014-01-01

After the first high power D-T experiment in JET in 1997 (DTE1), when JET was equipped with Carbon PFC's, a proposed second high power (up to ∼40MW) D-T campaign (DTE2) in the current Be/W vessel will address essential operational, technical, diagnostics and scientific issues in support of ITER. These experiments are proposed to minimize the risks to ITER by testing strategies for the management of the in-vessel tritium content, by providing the basis for transferring operational scenarios from non-active operation to D-T mixtures and by addressing the issue of the neutron measurement accuracy. Dedicated campaigns with operation in Deuterium, Hydrogen and Tritium before the D-T campaign proper will allow the investigation of isotope scaling of the H-mode transition, pedestal physics, heat, particle, momentum and impurity transport in much greater detail than was possible in DTE1. The D-T campaign proper will include validations of the baseline ELMy H-Mode scenario, of the hybrid H-mode and advanced tokamak scenarios, as well as the investigation of alpha particle physics and the qualification of ICRH scenarios suitable for D-T operation. This paper reviews the scientific goals of DTE2 together with a summary of the results of DTE1

Burn characteristics of compressed fuel pellets for D-3He inertial fusion

International Nuclear Information System (INIS)

Nakao, Y.; Honda, T.; Honda, Y.; Kudo, K.; Nakashima, H.

1992-01-01

In this paper, the feasibility of using D- 3 He fuel in inertial confinement fusion is examined by using a hydrodynamics code that includes neutron and charged-particle transport routines. The use of a small amount of deuterium-tritium (D-T) ignitor is indispensable. Burn simulations are made for quasi-isobaric D-T/D- 3 He pellet models compressed to 5000 times the liquid density. Substantial fuel gains (∼500) are obtained from pellets having parameters ρR D-T = 3 g/cm 2 and ρR total = 14 g/cm 2 and a central spark temperature of 5 keV. The amount of driver energy needed to achieve these gains is estimated to be ∼ 30 MJ when the coupling efficiency is 10%. The driver energy requirement can be reduced by using spin-polarized D-T and D- 3 He fuels

Tritium containment of controlled thermonuclear fusion reactor

International Nuclear Information System (INIS)

Tanaka, Yoshihisa; Tsukumo, Kiyohiko; Suzuki, Tatsushi

1979-01-01

It is well known that tritium is used as the fuel for nuclear fusion reactors. The neutrons produced by the nuclear fusion reaction of deuterium and tritium react with lithium in blankets, and tritium is produced. The blankets reproduce the tritium consumed in the D-T reaction. Tritium circulates through the main cooling system and the fuel supply and evacuation system, and is accumulated. Tritium is a radioactive substance emitting β-ray with 12.6 year half-life, and harmful to human bodies. It is an isotope of hydrogen, and apt to diffuse and leak. Especially at high temperature, it permeates through materials, therefore it is important to evaluate the release of tritium into environment, to treat leaked tritium to reduce its release, and to select the method of containing tritium. The permeability of tritium and its solubility in structural materials are discussed. The typical blanket-cooling systems of nuclear fusion reactors are shown, and the tungsten coating of steam generator tubes and tritium recovery system are adopted for reducing tritium leak. In case of the Tokamak type reactor of JAERI, the tritium recovery system is installed, in which the tritium gas produced in blankets is converted to tritium steam with a Pd-Pt catalytic oxidation tower, and it is dehydrated and eliminated with a molecular sieve tower, then purified and recovered. (Kako, I.)

Measurements of TFTR D-T radiation shielding efficiency

International Nuclear Information System (INIS)

Kugel, H.W.; Ascione, G.; Elwood, S.; Gilbert, J.; Ku, L.P.; Levine, J.; Rule, K.; Azziz, N.; Goldhagen, P.; Hajnal, F.

1994-11-01

Measurements of neutron and gamma dose-equivalents were performed in the Test Cell, at the outer Test Cell wall, in nearby work areas, and out to the nearest property lines at a distance of 180 m. Argon ionization chambers, moderated 3 He proportional counters, and fission chamber detectors were used to obtain measurements of neutron and gamma dose-equivalents per D-T neutron during individual TFTR discharges. These measured neutron and gamma D-T dose-equivalents per TFTR neutron characterize the effects of local variations in material density resulting from the complex asymmetric site geometry. The measured dose-equivalents per TFTR D-T neutron and the cumulative neutron production were used to determine that the planned annual TFTR neutron production of 1 x 10 21 D-T neutrons is consistent with the design objective of limiting the total dose-equivalent at the property line, from all radiation sources and pathways, to less than 10 mrem per year

Probing thermonuclear burning on accreting neutron stars

Science.gov (United States)

Keek, L.

2008-12-01

that the models need to be extended with a new heat source. Another rare phenomenon is the occurrence of bursts with recurrence times of less than 30 minutes. In a long set of observations of the source EXO 0748-676 we find for the first time triple bursts, where three bursts occur within 30 minutes. This time is too short to accrete new fuel for the next burst, which suggests that not all hydrogen and helium is burned during the first burst. Finally, using a hydrodynamic stellar evolution code we create a multi-zone numerical model of the neutron star envelope. For the first time we include mixing due to rotation and a rotationally induced magnetic field. We find that thermonuclear burning proceeds in a stable manner at a lower heat flux of the crust for models including mixing. This may explain the observed transition of stable to unstable burning at a lower mass accretion rate than models previously predicted.

Controlled thermonuclear fusion. Present state and prospective

International Nuclear Information System (INIS)

Consoli, T.

1976-01-01

The interest of thermonuclear fusion for energy production is underlined. The present state of the research in this field is presented, emphasis being given to Tokamak configurations. The problems concerning confinement and additional heating in these devices are presented [fr

Direct conversion of nuclear energy into radiation: New direction in thermonuclear laser fusion

International Nuclear Information System (INIS)

Babaev, Yu.N.; Vedenov, A.A.; Filyukov, A.A.

1995-01-01

In investigations dealing with thermonuclear fusion, a radical new direction appeared some time ago, namely the direct conversion of nuclear and thermonuclear energy into radiation energy. This paper reviews early work on this topic in Russia and the United States and discusses some recent new directions

Fuel enrichment and temperature distribution in nuclear fuel rod in (D-T) driven hybrid reactor system

Energy Technology Data Exchange (ETDEWEB)

Osman, Ypek [Suleyman Demirel Universitesi Muhendislik-Mimarlyk Fakultesi, Isparta (Turkey)

2001-07-01

In this study, melting point of the fuel rod and temperature distribution in nuclear fuel rod are investigated for different coolants under various first wall loads (P{sub w}, =5, 6, 7, 8, 9, and 10 MWm{sup -2}) in Fusion-Fission reactor fueled with 50%LWR +50%CANDU. The fusion source of neutrons of 14.1 MeV is simulated by a movable target along the main axis of cylindrical geometry as a line source. In addition, the fusion chamber was thought as a cylindrical cavity with a diameter of 300 cm that is comparatively small value. The fissile fuel zone is considered to be cooled with four different coolants, gas, flibe (Li{sub 2}BeF{sub 4}), natural lithium (Li), and eutectic lithium (Li{sub 17}Pb{sub 83}). Investigations are observed during 4 years for discrete time intervals of{delta}t= 0.5 month and by a plant factor (PF) of 75%. Volumetric ratio of coolant-to fuel is 1:1, 45.515% coolant, 45.515% fuel, 8.971% clad, in fuel zone. (author)

1D thermonuclear model for x-ray transients

International Nuclear Information System (INIS)

Wallace, R.K.

1982-01-01

The thermonuclear evolution of a 1.41 M solar mass neutron star, with a radius of 14.3 km, accreting various mixtures of hydrogen, helium, and heavy elements at rates of 10 -11 to 10 -10 M solar mass/yr is examined, in conjunction with S.E. Woosley and T.A. Weaver, using a one-dimensional numerical model. We have ignored any effects due to general relativity or magnetic fields. Two cases shall be discussed. In both models, the accretion rate is such that the hydrogen shell burns to helium in steady state, with the hydrogen burning stabilized by the β-limited CNO cycle. A thick helium shell is produced, which is eventually ignited under extremely degenerate conditions, producing a thermonuclear runaway

Use of code DTF-4 for determining the coefficient of back-reflection of the neutron within the thermonuclear plasma of a thermonuclear reactor controlled by the rate of the fission reactions. Pt. 1

International Nuclear Information System (INIS)

Cristea, G.

1975-01-01

The neutron problems are discussed of the thermonuclear reactor controlled by the rate of the fission reactions. The results obtained by rolling the DTF-4 program in a spherical geometry in the case of an ''external source'' problem permit to draw conclusions concerning the problems of the neutronics system of this thermonuclear reactor type. A relation is deduced for estimating the coefficient of back-reflection of the neutrons within the thermonuclear plasma and the focussion system is discussed of the neutronics of this reactor type

Sonoluminescence, shock waves, and micro-thermonuclear fusion

International Nuclear Information System (INIS)

Moss, W.C.; Clarke, D.B.; White, J.W.; Young, D.A.

1995-08-01

We have performed numerical hydrodynamic simulations of the growth and collapse of a sonoluminescing bubble in a liquid. Our calculations show that spherically converging shock waves are generated during the collapse of the bubble. The combination of the shock waves and a realistic equation of state for the gas in the bubble provides an explanation for the measured picosecond optical pulse widths and indicates that the temperatures near the center of the bubble may exceed 3O eV. This leads naturally to speculation about obtaining micro-thermonuclear fusion in a bubble filled with deuterium (D 2 ) gas. Consequently, we performed numerical simulations of the collapse of a D 2 bubble in D 2 0. A pressure spike added to the periodic driving amplitude creates temperatures that may be sufficient to generate a very small, but measurable number of thermonuclear D-D fusion reactions in the bubble

MUON DETECTORS: DT

CERN Multimedia

C. Fernandez Bedova and M. Dallavalle

2010-01-01

After successful operation during the 2009 LHC run, a number of fixes and improvements were carried out on the DT system the winter shutdown. The main concern was related with the impact of the extensive water leak that happened in October in YE+1. Opening of CMS end-caps allowed the DT crew to check if any Minicrates (containing the first level of readout and trigger electronics) in YB+2 and YB-2 were flooded with water. The affected region from top sectors in YB+2 reaches down to the bottom sectors in YB-2 following the water path in the barrel from end to end. No evidence of water penetration was observed, though the passage of water left oxidation and white streaks on the iron and components. In particular, large signs of oxidation have been seen on the YB-2 MB1 top and bottom stations. Review of the impact in YB+1 remains for future openings of CMS wheels, and at present, effort is focused on setting up the water leak detection system in the detector. Another important issue during this shutd...

Shock timing measurements in DT ice layers

Science.gov (United States)

Robey, H. F.; Celliers, P. M.; Moody, J. D.; Sater, J.; Parham, T.; Kozioziemski, B.; Dylla-Spears, R. J.; Ross, J. S.; Lepape, S.; Ralph, J. E.; Berzak Hopkins, L. F.; Kroll, J. J.; Yoxall, B. E.; Hamza, A. V.; Boehly, T. R.; Nikroo, A.; Landen, O. L.; Edwards, M. J.

2013-10-01

Shock timing experiments on the National Ignition Facility (NIF) are routinely conducted using the keyhole target geometry, in which the strength and timing of multiple shocks are measured in a liquid-deuterium (D2) filled capsule interior. These targets have recently been modified to improve the surrogacy to ignition implosions by replacing the standard, continuous liquid D2 capsule fill with a deuterium-tritium (DT) ice layer with a central DT gas fill. These experiments remove any possible material surrogacy difference between D2 and DT as well as incorporating the physics of multiple shock release and recompression events from an ice layer of finite thickness, an effect that is absent in the liquid-filled targets. Experimental results and comparisons with numerical simulation are presented. Prepared by LLNL under Contract DE-AC52-07NA27344.

Insulation structure of thermonuclear device

International Nuclear Information System (INIS)

Suzuki, Takayuki; Usami, Saburo; Tsukamoto, Hideo; Kikuchi, Mitsuru

1998-01-01

The present invention provides an insulating structure of a thermonuclear device, in which insulation materials between toroidal coils are not broken even if superconductive toroidal coils are used. Namely, a tokamak type thermonuclear device of an insulating structure type comprises superconductive toroidal coils for confining plasmas arranged in a circular shape directing the center each at a predetermined angle, and the toroidal coils are insulated from each other. The insulation materials are formed by using a biaxially oriented fiber reinforced plastics. The contact surface of the toroidal coils and the insulating materials are arranged so that they are contact at a woven surface of the fiber reinforced plastics. Either or both of the contact surfaces of the fiber reinforced plastics and the toroidal coils are coated with a high molecular compound having a low friction coefficient. With such a constitution, since the interlayer shearing strength of the biaxially oriented fiber reinforced plastics is about 1/10 of the compression strength, the shearing stress exerted on the insulation material is reduced. Since a static friction coefficient on the contact surface is reduced to provide a structure causing slipping, shearing stress does not exceeds a predetermined limit. As a result, breakage of the insulation materials between the toroidal coils can be prevented. (I.S.)

First wall of thermonuclear device

International Nuclear Information System (INIS)

Kizawa, Makoto; Koizumi, Makoto; Nishihara, Yoshihiro.

1990-01-01

The first wall of a thermonuclear device is constituted with inner wall tiles, e.g. made of graphite and metal substrates for fixing them. However, since the heat expansion coefficient is different between the metal substrates and intermediate metal members, thermal stresses are caused to deteriorate the endurance of the inner wall tiles. In view of the above, low melting metals are disposed at the portion of contact between the inner wall tiles and the metal substrates and, further, a heat pipe structure is incorporated into the metal substrates. Under the thermal load, for example, during operation of the thermonuclear device, the low melting metals at the portion of contact are melted into liquid metals to enhance the state of contact between the inner wall tiles and the metal substrate to reduce the heat resistance and improve the heat conductivity. Even if there is a difference in the heat expansion coefficient between the inner wall tiles and the metal substrates, neither sharing stresses not thermal stresses are caused. Further, since the heat pipe structure is incorporated into the metal substrates, the lateral unevenness of the temperature in the metal substrates can be eliminated. Thus, the durability of the inner wall tiles can be improved. (N.H.)

The laser thermonuclear fusion

International Nuclear Information System (INIS)

Coutant, J.; Dautray, R.; Decroisette, M.; Watteau, J.P.

1987-01-01

Principle of the thermonuclear fusion by inertial confinement: required characteristics of the deuterium-tritium plasma and of the high power lasers to be used Development of high power lasers: active media used; amplifiers; frequency conversion; beam quality; pulse conditioning; existing large systems. The laser-matter interaction: collision and collective interaction of the laser radiation with matter; transport of the absorbed energy; heating and compression of deuterium-tritium; diagnoses and their comparison with the numerical simulation of the experiment; performances. Conclusions: difficulties to overcome; megajoule lasers; other energy source: particles beams [fr

Thermonuclear device

International Nuclear Information System (INIS)

Oosaki, Osamu; Masuda, Kenju.

1980-01-01

Purpose: To provide excellent electric properties and high reliability in a thermonuclear device by improving a current collecting board connected to a coil device. Constitution: A current collecting board element perforated with an opening for enserting a connecting terminal is sized to be inserted into a plating tank, and is surface treated in the plating tank. Only the current collecting board element preferably surface treated is picked up. A plurality of such current collecting board elements are connected and welded to form a large current collecting board. In this manner, the current collecting board having several m 2 to several ten order m 2 in area can be obtained as preferably surface treated at the connecting terminal hole. The current collecting board element can be determined in shape with the existing facility without increasing the size of a surface treating tank. (Kamimura, M.)

HYPERFUSE: a hypervelocity inertial confinement system for fusion energy production and fission waste transmutation

International Nuclear Information System (INIS)

Makowitz, H.; Powell, J.R.; Wiswall, R.

1980-01-01

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs, 90 Sr, 129 I, 99 Tc, etc. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n,2n), (n,α), (n,γ), etc.) that convert the long-lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product. The transmutation parametric studies conclude that the design of the hypervelocity projectiles should emphasize the achievement of high densities in the transmutation regions (greater than the DT fusion fuel density), as well as the DT ignition and burn criterion (rho R=1.0 to 3.0) requirements

MUON DETECTOR: BARREL DRIFT TUBES (DT) AND ALIGNMENT

CERN Multimedia

Marco Dallavalle

After months of cosmics data taking the drift tube (DT) detector is in good shape, ready for LHC beams. Several hundreds of millions of cosmics events have been recorded; out of those, more than 90% were triggered by the DT system. Data integrity analyses have shown a very reliable read-out system, also during high rate tests. With a 98% of the detector operational, only awaiting the arrival of some low voltage modules and for the completion of the DT Track Finder system, data taking is starting to become routine job. These continuous running exercises have been very useful to study performance and reliability of the detector in a medium term period, allowing understanding and fixing failures that have occurred with low frequency. Drift tubes have become a very stable system, becoming a service of muon triggering for the tracker after its final installation. During the last months, major efforts have taken place in synchronization tasks, within the DT system (250 chambers) and also with the rest of the CMS su...

Thermal insulation layer for the vacuum containers of a thermonuclear device

International Nuclear Information System (INIS)

Nishikawa, Masana; Yamada, Masao; Kameari, Akihisa; Niikura, Setsuo.

1980-01-01

Purpose: To prevent temperature rise of a thermal insulation layer for a vacuum container of a thermonuclear device higher than allowable value when irradiated by neutron by constructing the layer of a cooling unit in thermal insulation material. Constitution: A metal plate attached with cooling pipes is buried in a thermal insulation material forming a thermal insulation layer to form the layer provided between a vacuum container of a thermonuclear device and a shield. (Yoshihara, H.)

International research co-operation in the field of controlled thermonuclear fusion

International Nuclear Information System (INIS)

Conscience, J.-F.

2003-01-01

This final report for the Swiss Federal Office of Education and Science presents a review of activities carried out in 2002 within the framework of the International Experimental Thermonuclear Reactor (ITER) project that involves contributions from Canada, Japan, the Russian Federation and the European Union. Further agreements on the development of a fusion reactor with other countries, including Switzerland, the USA and China, are mentioned. The first chapter describes the current state of research on electricity production using nuclear fusion and discusses feasibility, safety, environmental, fuel supply and economic aspects. A second chapter reviews global efforts in the fusion area, including ITER and EURATOM projects and the activities running under the European Fusion Development Agreement EFDA and the JET Implementing Agreement. Finally, a third chapter deals with fusion research activities in Switzerland and the contributions made to international research by Swiss universities and institutes

Laser drivers for inertial confinement fusion

International Nuclear Information System (INIS)

Holzrichter, J.F.

1983-01-01

Inertial Confinement Fusion (ICF) is the technology that we are developing to access the vast stored energy potential of deuterium fuel located in the world's water supply. This form of fusion is accomplished by compressing and heating small volumes of D-T fuel to very high temperatures (greater than 100M 0 C) and to very high densities (greater than 1000 times the normal liquid density). Under these fuel conditions, a thermonuclear reaction can occur, leading to a net energy release compared to the energy used to heat the fuel initially. To accomplish the condition where fusion reactions begin, effective drivers are required. These are lasers or particle beam accelerators which can provide greater than 10 14 W/cm 2 over millimeter scale targets with an appropriately programmed intensity vs time. At present, we are using research lasers to obtain an understanding of the physics and engineering of fuel compression

Prospects for alternative Fusion Fuels

International Nuclear Information System (INIS)

Glancy, J.

1986-01-01

The author has worked on three different magnetic confinement concepts for alternate fusion fueled reactors: tokamaks; tanden mirrors, and reversed field pinches. The focus of this article is on prospects for alternate fusion fuels as the author sees them relative to the other choices: increased numbers of coal plants, fission reactors, renewables, and D-T fusion. Discussion is limited on the consideration of alternate fusion fuels to the catalyzed deuterium-deuterium fuel cycle. Reasons for seeking an alternate energy source are cost, a more secure fuel supply, environmental impact and safety. The technical risks associated with development of fusion are examined briefly

Isotopic hydrology of Berrocal area (Toledo, Spain): I: Tritium in springs with thermonuclear resources

International Nuclear Information System (INIS)

1995-01-01

This book the study on isotopic hydrology in El Berrocal, Toledo (Spain). The special topic was the study about the tritium of springs with thermonuclear source. The study are articulated in 3 chapter: 1.- Chemical analysis of wastes 2.- Tritium with thermonuclear source 3.- Human resources

Thermonuclear device

International Nuclear Information System (INIS)

Kajiura, Soji.

1984-01-01

Purpose: To suppress the generation of electromagnetic forces and improve the strength of a vacuum container for sealing plasmas and of a support frame for covering the coils disposed around the periphery of the vacuum container. Constitution: Either one of the vacuum container or the support frame is made of a composite material, whose first material has low radioactivatability and the second has low radioactivatability and stronger electrical resistance than that of the first; therein, with the first material being disposed on the surface. The damage caused by neutrons resulted from thermonuclear reaction can be extremely small since the constituent is made of the material having the low radioactivatability. Further, eddy current does not occurs in the second material, but in the first material only in case magnetic fields change rapidly, whereby the electromagnetic force resulted in this portion is decreased as a whole. (Moriyama, K.)

Thermonuclear device

International Nuclear Information System (INIS)

Suzuki, Shohei

1988-01-01

Purpose: To obtain high voltage withstanding current introduction terminals not suffering from the effects of the reduction in the creeping voltage withstanding property by the application of magnetic fields. Constitution: This invention concerns a current introduction terminal for supplying electric current to coils for use in a thermonuclear device, etc. The conductor of the current introduction terminal on the side of vacuum is completely covered with solid insulator. This can eliminate the portion of securing the creeping withstanding voltage. The voltage withstanding characteristics of the solid insulator covering the portion of the conductor on the side of vacuum has a constant value irrespective of the atmosphere or the absence or presence of magnetic fields. Accordingly, the voltage withstanding characteristics of the current introduction terminal on the side of vacuum are determined by the property of the solid insulator, which is not reduced by the application of magnetic fields. (Ikeda, J.)

DT results of TFTR's alpha collector

International Nuclear Information System (INIS)

Herrmann, H.W.; Zweben, S.J.; Darrow, D.S.; Timberlake, J.R.; Macaulay-Newcombe, R.G.

1996-01-01

An escaping alpha collector probe has been developed for TFTR's DT phase to complement the results of the lost alpha scintillator detectors which have been operating on TFTR since 1988. Measurements of the energy distribution of escaping alphas have been made by measuring the range of alphas implanted into nickel foils located within the alpha collector. Exposed samples have been analyzed for 4 DT plasma discharges at plasma currents of 1.0 and 1.8 MA. The results at 1.0 MA are in good agreement with predictions for first orbit alpha loss at 3.5 MeV. The 1.8 MA results, however, indicate a large anomalous loss of partially thermalized alphas at an energy ∼30% below the birth energy and at a total fluence nearly an order of magnitude above expected first orbit loss. This anomalous loss is not observed with the lost alpha scintillator detectors in DT plasmas but does resemble the anomalous delayed loss seen in DD plasmas. Several potential explanations for this loss process are examined. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations

Measurements of DT and DD neutron yields by neutron activation on TFTR

International Nuclear Information System (INIS)

Barnes, C.W.; Larson, A.R.; LeMunyan, G.

1994-01-01

A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10 12 to over 10 18 , and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants. and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma,) accuracy of the measurements: also agreeing are yields from silicon foils using the ACTL library cross-section. While the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115 In(n,n) 115m In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments

Measurements of DT and DD neutron yields by neutron activation on TFTR

International Nuclear Information System (INIS)

Barnes, C.W.; Larson, A.R.; LeMunyan, G.

1995-03-01

A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10 12 to over 10 18 , and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants, and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma) accuracy of the measurements; also agreeing are yields from silicon foils using the ACTL library cross-section, while the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115 In(n.n') 115m In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments

Thermonuclear fusion: Current status and future prospects

International Nuclear Information System (INIS)

Bruhns, H.; Maisonnier, Ch.

1992-01-01

Thermonuclear Fusion holds great promises for becoming an important energy source for the future. Fusion research and development is undertaken in al major countries of the world. The European Community pursues fusion in a large programme which embraces all R and D in the field of magnetic confinement fusion in the Member States, and to which Sweden and Switzerland are fully associated. The long-term objective of the programme is the joint creation of safe, environmentally sound prototype reactors. The main R and D line of the Community Fusion Programme is fusion by toroidal magnetic confinement on the basis of the Tokamak concept. Some related concepts are also studied which possibly could offer advantages for a reactor, and keep-in-touch activities exist for other approaches. Several small and medium sized specialised devices in Associated Laboratories have been built by the Community Fusion Programme as well as the Joint European Torus (JET Joint Undertaking) which is the largest and the most successful fusion device in the world. Recently, fusion power in the megawatt range has been achieved in JET. The long timescale and the large effort needed for the development of fusion as an energy source have been important elements to foster international collaboration. Engineering Design Activities for an International Thermonuclear Experimental Reactor (ITER) are undertaken, under the auspices of the IAEA, by the European Community, Japan, the Russian Federation and the United States of America. The objective of ITER is to achieve self-sustained thermonuclear burn and its control under long-pulse operation and to provide basic data for the engineering of a demonstration fusion reactor. (author)

(D,T) Driven thorium hybrid blankets

International Nuclear Information System (INIS)

Al-Kusayer, T.A.; Khan, S.; Sahin, S.

1983-01-01

Recently, a project has started, with the aim to establish the neutronic performance and the basic design of an experimental fusionfission (hybrid) reactor facility, called AYMAN, in cylinderical geometry. The fusion reactor will have to be simulated by a (D,T) neutron generator. Fissile and fertile fuel will have to surround the neutron generator as a cylinderical blanket to simulate the boundary conditions of the hybrid blanket in a proper way. This geometry is consistent with Tandem Mirror Hybrid Blanket design and with most of the ICF blanket designs. A similar experimental installation will become operational around 1984 at the Swiss Federal Institute of Technology in Lausanne, Switzerland known under the project LOTUS. Due to the limited dimensions of the experimental cavity of the LOTUS-hybrid reactor, the LOTUS blankets have to be designed in plane geometry. Also, the bulky form of the Haefely neutron generator of the LOTUS facility obliges one to design a blanket in the plane geometry. This results in a vacuum left boundary conditions for the LOTUS blanket. The importance of a reflecting left boundary condition on the overall neutronic performance of a hybrid blanket has been analyzed in previous work in detail

On the sign of d2H/dt2

International Nuclear Information System (INIS)

Dipankar, R.

1977-11-01

For a system with a given energy that has N different possible states, the H function (of thermodynamics) satisfies d 2 H/dt 2 >0 if N( 2 H/dt 2 may be both positive and negative if N(>=)5. The case of N=4 remains undetermined

Possible applications of a hybrid thermonuclear energy source based on a DPF device in modern energy complexes

International Nuclear Information System (INIS)

Gribkov, V.A.; Tyagunov, M.G.

1983-01-01

A source of thermonuclear energy based on the dense plasma focus (DPF) device in a hybrid fusion-fission version is proposed. In its initial operating phase such a facility would be a net energy consumer and would breed fissile material; as the fissile content in the blanket increases, the installation would become a net energy producer. Under the proposed scheme of blanket operation, up to 50% of the uranium could be burned while maintaining electrical output and without refabrication of fuel elements. If desired, operation could continue after the fuel is almost completely exhausted to burn the nuclear waste. It is thought that the new source could become both technologically and economically feasible in the near future. Smooth control should present no problem and the speed at which the device could be brought up to full load should greatly improve the flexibility of the overall electrical supply system

Pharmacological effects and potential therapeutic targets of DT-13.

Science.gov (United States)

Khan, Ghulam Jilany; Rizwan, Mohsin; Abbas, Muhammad; Naveed, Muhammad; Boyang, Yu; Naeem, Muhammad Ahsan; Khan, Sara; Yuan, Shengtao; Baig, Mirza Muhammad Faran Ashraf; Sun, Li

2018-01-01

DT-13 is an isolated compound from Dwarf lillytruf tuber and currently among active research drugs by National Natural Science foundation of China for its several potential effects. The drug has been reported for its multiple pharmacological actions however no thorough review studies are available on it. Our present study is highlighting the pros and cons of DT-13 focusing on its potential pharmacological actions, therapeutic utilization and further exploration for novel targets. The drug possesses very low toxicity profile, quick onset and long duration of action with slow elimination that combinely makes it favorable for the clinical studies. In vivo and in vitro studies show that the drug regulates multiple cellular functions for its several pharmacological effects including, anti-adhesive effects via regulation of tissue factor and transforming growth factor; anti-migratory effects through indirect regulation of NM-IIA in the tumor microenvironment, Tissue factor, down-regulation of CCR5-CCL5 axis and MMP-2/9 inhibition; anti-metastatic effects via regulation of MMPs and tissue factor; pro-apoptotic effects by modulation of endocytosis of EGF receptor; anti-angiogenic effects via regulation of HIF-1α,ERK, Akt signalling and autophagy inducing characteristics by regulating PI3K/Akt/mTOR signalling pathway. In addition to anti-tumor activities, DT-13 has significant anti-inflammatory, cardioprotective, hepatoprotective and immunomodulating effects. Pharmaceutical dosage form and targeted drug delivery system for DT-13 has not been established yet. Moreover, DT-13, has not been studied for its action on brain, colorectal, hepatic, pancreatic, prostate and blood cancers. Similarly the effects of drug on carbohydrate and glucose metabolism is another niche yet to be explored. In some traditional therapies, crude drug from the plant is used against diabetic and neurological disorders that are not reported in scientific literature, however due to profound effects of

Physics of high performance JET plasmas in D-T

International Nuclear Information System (INIS)

2001-01-01

JET has recently operated with deuterium-tritium (D-T) mixtures, carried out an ITER physics campaign in hydrogen, deuterium, D-T and tritium, installed the Mark IIGB ''Gas Box'' divertor fully by remote handling and started physics experiments with this more closed divertor. The D-T experiments set records for fusion power (16.1 MW), ratio of fusion power to plasma input power (0.62, and 0.95±0.17 if a similar plasma could be obtained in steady-state) and fusion duration (4 MW for 4 s). A large scale tritium supply and processing plant, the first of its kind, allowed the repeated use of the 20 g tritium on site to supply 99.3 g of tritium to the machine. The H-mode threshold power is significantly lower in D-T, but the global energy confinement time is practically unchanged (no isotope effect). Dimensionless scaling ''Wind Tunnel'' experiments in D-T extrapolate to ignition with ITER parameters. The scaling is close to gyroBohm, but the mass dependence is not correct. Separating the thermal plasma energy into core and pedestal contributions could resolve this discrepancy (leading to proper gyroBohm scaling for the core) and also account for confinement degradation at high density and at high radiated power. Four radio frequency heating schemes have been tested successfully in D-T, showing good agreement with calculations. Alpha particle heating has been clearly observed and is consistent with classical expectations. Internal transport barriers have been established in optimised magnetic shear discharges for the first time in D-T and steady-state conditions have been approached with simultaneous internal and edge transport barriers. First results with the newly installed Mark IIGB divertor show that the in/out symmetry of the divertor plasma can be modified using differential gas fuelling, that optimised shear discharges can be produced, and that krypton gas puffing is effective in restoring L-mode edge conditions and establishing an internal transport barrier in

Physics of high performance jet plasmas in D-T

International Nuclear Information System (INIS)

1999-01-01

JET has recently operated with deuterium-tritium (D-T) mixtures, carried out an ITER physics campaign in hydrogen, deuterium, D-T and tritium, installed the Mark IIGB 'Gas Box' divertor fully by remote handling and started physics experiments with this more closed divertor. The D-T experiments set records for fusion power (16.1 MW), ratio of fusion power to plasma input power (0.62, and 0.95±0.17 if a similar plasma could be obtained in steady-state) and fusion duration (4 MW for 4 s). A large scale tritium supply and processing plant, the first of its kind, allowed the repeated use of the 20 g tritium on site to supply 99.3 g of tritium to the machine. The H-mode threshold power is significantly lower in D-T, but the global energy confinement time is practically unchanged (no isotope effect). Dimensionless scaling 'Wind Tunnel' experiments in D-T extrapolate to ignition with ITER parameters. The scaling is close to gyroBohm, but the mass dependence is not correct. Separating the thermal plasma energy into core and pedestal contributions could resolve this discrepancy (leading to proper gyroBohm scaling for the core) and also account for confinement degradation at high density and at high radiated power. Four radio frequency heating schemes have been tested successfully in D-T, showing good agreement with calculations. Alpha particle heating has been clearly observed and is consistent with classical expectations. Internal transport barriers have been established in optimised magnetic shear discharges for the first time in D-T and steady-state conditions have been approached with simultaneous internal and edge transport barriers. First results with the newly installed Mark IIGB divertor show that the in/out symmetry of the divertor plasma can be modified using differential gas fuelling, that optimised shear discharges can be produced, and that krypton gas puffing is effective in restoring L-mode edge conditions and establishing an internal transport barrier in such

Potential role of advanced fuels in inertial confinement fusion

International Nuclear Information System (INIS)

Miley, G.

1981-01-01

The potential importance of developing advanced (non D-T) fuel pellets for inertial confinement is discussed. Reduced radioactivity due to low tritium involvement and less neutron activation, improved blanket flexibility with the removal of tritium breeding requirements, and improved mating of the output energy spectrum with non-electrical applications such as synthetic fuel production could lead to technical advantages and earlier public acceptance. As a possible first step to advanced-fuel pellets, the A-FLINT concept of a D-T core ignited, deuterium pellet is proposed which would offer tritium self-sufficiency. A design is described that uses 0.1-MJ internal energy in a rhoR1--7 gm/cm2'' compressed pellet, giving a tritium breeding ratio of 1--1.0 and an internal pellet gain of 1--700

Study on structural materials used in thermonuclear fusion technology

International Nuclear Information System (INIS)

Billa, R.; Amaral, D.

1995-01-01

The main problem related to the construction of a thermonuclear fusion reactor is the absence of suitable materials for the process, concerning to temperature limits, heat flux and life time. The first wall is the most critical part of the structure, being submitted to radiation effects, ionic corrosion and coolant, besides thermal fatigue and tension produced by cyclical burning. The AISI 316(17-12SPH) stainless steel is used as structural material, which has a wide known database. This work proposes an alternative material study to be used in the future thermonuclear fusion reactors. As a option a study on the utilization of Cr-Mn(Fe-17 Mn-10 Cr-0,1 C) steels and their alloy variations is presented

Alpha particle studies during JET DT experiments

International Nuclear Information System (INIS)

1999-01-01

The 1997 DT experiment (DTE1) at the Joint European Torus included studies of the behaviour of alpha particles in high temperature plasmas. Clear alpha particle heating was observed in a series of otherwise similar 10MW hot-ion H-modes by scanning the DT mixture from 0%T to 93%T. Maxima in central temperature and energy content were obtained which corresponded with the maximum in fusion yield. Alfven Eigenmodes (AEs) have been detected in JET, driven by NBI or ICRH fast ions. However, in agreement with theory, no AE activity was observed in DT plasmas which could be attributed to alpha particle drive, except in the afterglow of some Optimised Shear pulses. Ion Cyclotron Emission (ICE) was detected at harmonics of the alpha particle cyclotron frequency at the outer edge of the plasma. The ICE is interpreted as being close to magnetoacoustic cyclotron instability, driven by inverted alpha distributions at the plasma edge. The high-energy neutral particle spectra showed features, which are ascribed to a mixture of alphas, neutralised by helium-like impurities, and deuterons, born from elastic collisions with alpha particles and neutralised by hydrogen-like impurities. The results of all these studies are consistent with classical alpha particle trapping and slowing-down. Future DT experiments will aim to increase alpha particle pressure, so interactions with plasma instabilities can be studied. The measurement of knock-on neutral triton spectra offers a clean way to determine confined alpha densities in these future experiments. (author)

Alpha particle studies during JET DT experiments

International Nuclear Information System (INIS)

2001-01-01

The 1997 DT experiment (DTE1) at the Joint European Torus included studies of the behaviour of alpha particles in high temperature plasmas. Clear alpha particle heating was observed in a series of otherwise similar 10MW hot-ion H-modes by scanning the DT mixture from 0%T to 93%T. Maxima in central temperature and energy content were obtained which corresponded with the maximum in fusion yield. Alfven Eigenmodes (AEs) have been detected in JET, driven by NBI or ICRH fast ions. However, in agreement with theory, no AE activity was observed in DT plasmas which could be attributed to alpha particle drive, except in the afterglow of some Optimised Shear pulses. Ion Cyclotron Emission (ICE) was detected at harmonics of the alpha particle cyclotron frequency at the outer edge of the plasma. The ICE is interpreted as being close to magnetoacoustic cyclotron instability, driven by inverted alpha distributions at the plasma edge. The high-energy neutral particle spectra showed features, which are ascribed to a mixture of alphas, neutralised by helium-like impurities, and deuterons, born from elastic collisions with alpha particles and neutralised by hydrogen-like impurities. The results of all these studies are consistent with classical alpha particle trapping and slowing-down. Future DT experiments will aim to increase alpha particle pressure, so interactions with plasma instabilities can be studied. The measurement of knock-on neutral triton spectra offers a clean way to determine confined alpha densities in these future experiments. (author)

Design Features of the Neutral Particle Diagnostic System for the ITER Tokamak

Science.gov (United States)

Petrov, S. Ya.; Afanasyev, V. I.; Melnik, A. D.; Mironov, M. I.; Navolotsky, A. S.; Nesenevich, V. G.; Petrov, M. P.; Chernyshev, F. V.; Kedrov, I. V.; Kuzmin, E. G.; Lyublin, B. V.; Kozlovski, S. S.; Mokeev, A. N.

2017-12-01

The control of the deuterium-tritium (DT) fuel isotopic ratio has to ensure the best performance of the ITER thermonuclear fusion reactor. The diagnostic system described in this paper allows the measurement of this ratio analyzing the hydrogen isotope fluxes (performing neutral particle analysis (NPA)). The development and supply of the NPA diagnostics for ITER was delegated to the Russian Federation. The diagnostics is being developed at the Ioffe Institute. The system consists of two analyzers, viz., LENPA (Low Energy Neutral Particle Analyzer) with 10-200 keV energy range and HENPA (High Energy Neutral Particle Analyzer) with 0.1-4.0MeV energy range. Simultaneous operation of both analyzers in different energy ranges enables researchers to measure the DT fuel ratio both in the central burning plasma (thermonuclear burn zone) and at the edge as well. When developing the diagnostic complex, it was necessary to account for the impact of several factors: high levels of neutron and gamma radiation, the direct vacuum connection to the ITER vessel, implying high tritium containment, strict requirements on reliability of all units and mechanisms, and the limited space available for accommodation of the diagnostic hardware at the ITER tokamak. The paper describes the design of the diagnostic complex and the engineering solutions that make it possible to conduct measurements under tokamak reactor conditions. The proposed engineering solutions provide a safe—with respect to thermal and mechanical loads—common vacuum channel for hydrogen isotope atoms to pass to the analyzers; ensure efficient shielding of the analyzers from the ITER stray magnetic field (up to 1 kG); provide the remote control of the NPA diagnostic complex, in particular, connection/disconnection of the NPA vacuum beamline from the ITER vessel; meet the ITER radiation safety requirements; and ensure measurements of the fuel isotopic ratio under high levels of neutron and gamma radiation.

Some safety considerations in laser-controlled thermonuclear reactors. Final report

International Nuclear Information System (INIS)

Botts, T.E.; Breton, D.; Chan, C.K.; Levy, S.I.; Sehnert, M.; Ullman, A.Z.

1978-07-01

A major objective of this study was to identify potential safety questions for laser controlled thermonuclear reactors. From the safety viewpoint, it does not appear that the actual laser controlled thermonuclear reactor conceptual designs present hazards very different than those of magnetically confined fusion reactors. Some aspects seem beneficial, such as small lithium inventories, and the absence of cryogenic devices, while other aspects are new, for example the explosion of pressure vessels and laser hazards themselves. Major aspects considered in this report include: (a) general safety considerations, (b) tritium inventories, (c) system behavior during loss of flow accidents, and (d) safety considerations of laser related penetrations

The comparison of extraction of energy in two-cascade and one-cascade targets

Energy Technology Data Exchange (ETDEWEB)

Dolgoleva, G. V., E-mail: dolgg@list.ru [National Research Tomsk State University, 36, Lenin Ave., 634050, Tomsk (Russian Federation); Ponomarev, I. V., E-mail: wingof17@mail.ru [Moscow State University, Department of Mechanics and Mathematics, 1, Vorobyovy Gory, Moscow,119961 (Russian Federation)

2016-01-15

The paper is devoted to numerical designing of cylindrical microtargets on the basis of shock-free compression. When designing microtargets for the controlled thermonuclear fusion, the core tasks are to select geometry and make-up of layers, and the law of energy embedding as well, which allow receiving of “burning” of deuterium- tritium mix, that is, the existence of thermonuclear reactions of working area. Yet, the energy yield as a result of thermonuclear reactions has to be more than the embedded energy (the coefficient of amplification is more than a unit). So, an important issue is the value of the embedded energy. The purpose of the present paper is to study the extraction of energy by working DT area in one-cascade and two-cascade targets. A bigger extraction of energy will contribute to a better burning of DT mix and a bigger energy yield as a result of thermonuclear reactions. The comparison of analytical results to numerical calculations is carried out. The received results show advantages of a two-cascade target compared to a one-cascade one.

eDT and Model-based Configuration of 12GeV CEBAF

Energy Technology Data Exchange (ETDEWEB)

Turner, Dennison L. [Jefferson Lab, Newport News, VA (United States)

2015-09-01

This poster will discuss model-driven setup of CEBAF for the 12GeV era, focusing on the elegant Download Tool (eDT). eDT is a new operator tool that generates magnet design setpoints for various machine energies and pass configurations. eDT was developed in the effort towards a process for reducing machine configuration time and reproducibility by way of an accurate accelerator model.

Tritium monitoring within the reactor hall of a DT fusion reactor

International Nuclear Information System (INIS)

Jalbert, R.A.

1983-01-01

Monitoring the reactor hall atmosphere of DT-fueled fusion reactors will probably be performed with conventional ion chamber and proportional counter instruments modified as necessry to deal with the background radiation. Background includes external neutron and gamma radiation and internal beta-gamma radiation from the activated atmosphere. Although locating instruments in remote areas of the reactor hall and adding local shielding and electronic compensation may be feasible, placing the instruments in accessible low-background areas outside of the reactor hall and doing remote sampling is preferable and solves most of the radiation problems. The remaining problem of the activated atmosphere may be solved by recently developed instruments in conjunction with the use of semi-permeable membranes currently under development and evaluation

Thermonuclear reactor

International Nuclear Information System (INIS)

Yasutomi, Yoshiyuki; Nakagawa, Moroo; Sawai, Yuichi; Chiba, Akio; Suzuki, Yasutaka.

1997-01-01

Silicon composited with reinforcing metals is used for a divertor cooling substrate having an effect as a cooling tube to provide a silicon base composite material having increased electric resistance and toughness. The blending ratio of reinforcing materials in the form of granules, whiskers or long fibers is controlled in order to control heat conductivity, electric resistivity and mechanical performances. The divertor cooling substrate comprising the silicon base composite material is integrated with a plasma facing material. The production method therefor includes ordinary metal matrix composite forming methods such as powder metallurgy, melting penetration method, high pressure solidification casting method, centrifugal casting method and vacuum casting method. Since the cooling plate is constituted with the light metal and highly electric resistant metal base composite material, sharing force due to eddy current can be reduced, and radiation exposure can be minimized. Accordingly, a cooling structure for a thermonuclear reactor effective for the improvement of environmental problems caused by waste disposal can be attained. (N.H.)

Radiation damages of material surfaces by plasma emission in thermonuclear devices. Methods of study of surface phenomena and simulation effect of thermonuclear plasma

International Nuclear Information System (INIS)

Rybalko, V.F.

1978-01-01

Phenomena that can introduce a controlling contribution into the erosion of the first wall surface in thermonuclear reactor are reviewed. Considered are the main characteristics of the physical disintegration: dependence of the disintegration coefficient upon the energy and the incidence angle of the bombarding particles, upon the atomic number of the material of the target and the type of bombarding particles. Stressed is the lack of reliable data on the disintegration of materials by light ions, which are of a maximum interest in relation to the controlled thermonuclear synthesis. The chemical disintegration and some regularities of it for the carbon-hydrogen and carbon-oxygen systems are discussed briefly. Listed are the main properties of blistering and its contribution to the erosion of crystalline surfaces

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

Catalyzed deuterium fueled tokamak reactors

International Nuclear Information System (INIS)

Southworth, F.H.

1977-01-01

Catalyzed deuterium fuel presents several advantages relative to D-T. These are, freedom from tritium breeding, high charged particle power fraction and lowered neutron energy deposition in the blanket. Higher temperature operation, lower power densities and increased confinement are simultaneously required. However, the present study has developed designs which have capitalized upon the advantages of catalyzed deuterium to overcome the difficulties associated with the fuel while obtaining high efficiency

D-T plasma of self-sustained burning under high performance

International Nuclear Information System (INIS)

Gong Xueyu

2003-01-01

By adopting a Bohm-type thermal diffusion coefficient related to the energy confinement enhancement factor H within the conventional magnetic shear regime, and a mixed Bohm-gyro-Bohm thermal diffusion coefficient related to the shear within the negative central magnetic shear regime, considering the effect of the α particle anomalous diffusion and the dynamic feedback heating, and starting from energy transport of electrons and ions, we have studied the high performance self-sustaining burning deuterium-tritium plasma under a given plasma density profile for the two different kinds of magnetic shear regimes. Some conclusions are obtained: under the conventional shear, only when H≥3, the D-T burning can produce a large power output, and when H is larger than a certain value (H≅4), D-T plasma self-sustained burning can be maintained without the dynamic feedback heating; under the negative central shear, the plasmas have a higher plasma performance and a larger power output than that under conventional shear, and D-T plasma self-sustained burning can be maintained without the dynamic feedback heating power, the suitable alpha particle diffusion is advantage ous to D-T plasma burning under the conventional shear, and D-T self-sustained burning cannot be maintained under a large α particle anomalous diffusion for the negative central shear. The dynamic feedback heating power is important for sustaining D-T plasma burning under the conventional shear

Repairing method and device for thermonuclear device

International Nuclear Information System (INIS)

Sakurai, Akiko; Masumoto, Hiroshi; Tachikawa, Nobuo.

1995-01-01

The present invention provides a method of and a device for repairing a first wall and a divertor disposed in a vacuum vessel of a thermonuclear device. Namely, an armour tile of the divertor secured, by a brazing material, in a vacuum vessel of the thermonuclear device in which high temperature plasmas of deuterium and tritium are confined to cause fusion reaction is induction-heated or heated by microwaves to melt the brazing material. Only the armour tile is thus exchanged by its attachment/detachment. This device comprises, in the vacuum vessel, an armour tile attaching/detaching manipulator and a repairing manipulator comprising a heating manipulator having induction heating coils at the top end thereof. Induction heating coils are connected to an AC power source. According to the present invention, the armour tile is exchanged without taking the divertor out of the vacuum vessel. Therefore, cutting of a divertor cooling tube for taking the divertor out of the vacuum vessel and re-welding of the divertor for attaching it to the vacuum vessel again are no more necessary. (I.S.)

Calculations of the Auger deexcitation rate of dtμ within the muonic quasimolecule (dtμ)dee

Science.gov (United States)

Armour, E. A. G.; Lewis, D. M.; Hara, S.

1992-12-01

A key process in muon-catalyzed fusion is the deexcitation of dtμ within the resonant muonic quasimolecule (dtμ)dee, by emission of an Auger electron. The dtμ in the quasimolecule is initially in a weakly bound excited state with J=1 and v=1. Calculations are carried out of the rate of the dominant transition to the state with J=0 and v=1. Use is made of the dipole matrix element obtained for this transition by Scrinzi and Szalewicz [Phys. Rev. A 39, 2855 (1989)]. Full account is taken of the molecular nature of the quasimolecule. The continuum electronic wave functions for the Auger electron for all four contributing symmetries, i.e., Σ+g, Σ+u, Πu, and Πg, are first obtained by a two-center Coulomb calculation and a static-exchange calculation, extended to include dipole polarization. Comparison is then made with the results of a calculation in which the Σ+μ and Πu wave functions are obtained as in a previous paper by Armour and Lewis [J. Phys. B 23, L25 (1990)] and the Σ+g and Πg wave functions are obtained by the Kohn method. There are significant differences between the contributions from the individual symmetries, but the overall values for the deexcitation rate are all of the same order of magnitude as the results of earlier calculations.

Upgrades of Diagnostic Techniques and Technologies for JET next D-T Campaigns

Energy Technology Data Exchange (ETDEWEB)

Murari, Andrea [Consorzio RFX - CNR, ENEA, INFN, Universita di Padova, Acciaierie Venete SpA,Corso Stati Uniti 4, 35127 Padova (Italy)

2015-07-01

JET next D-T campaign is presently scheduled for the year 2017. The main scientific objectives include the assessment of the isotopic effects on various plasma aspects: mainly on confinement, on the threshold to access the H mode and on ELM behaviour. From a technical point of view, the total yield of the entire D-T phase is expected to be 1.7 1021 neutrons, about a factor of six higher than the previous main D-T campaign on JET, DTE1. Therefore the radiation field will be quite relevant for next step devices, since the neutron flux at the first wall (∼10{sup 16} n/cm{sup 2}s), for example, will be comparable to the one in ITER behind the blanket. From a point of view of diagnostics developments, for many years JET diagnostics have been upgraded in order to provide adequate support for the scientific exploitation of a D-T campaign. The main efforts have concentrated on improving three main aspects of JET measuring capability: 1) the quality of the measurements of the electron and ion fluids to support the plasma physics programme 2) the diagnostic for the fusion products 3) diagnostic technologies for ITER. In terms of general diagnostic capability, compared to the previous DTE1, JET diagnostics have a much better spatial and temporal resolution of both the ion and electron fluid (about one order of magnitude improvement for each parameter). The consistency of the various independent measurements of the same parameters has also increased significantly; the three independent measurements of the electron temperature, for example, agree now within 5%. Moreover, solutions are being addressed to operate some cameras, both visible and IR, even during the full D-T phase to provide imaging of the plasma and the first wall. Various upgrades of neutral particle analysis are being considered, mainly to measure the isotopic composition. A new set of reflectometers is expected to provide valuable information about the changes in the turbulence with the different fuel mixtures

Thermonuclear pulsors engineering

International Nuclear Information System (INIS)

Ramos, Ruben F.

2001-01-01

The neutronic radiation has several applications, such as activation analysis of different substances, neutron radiography, molecular structures study, cancer therapy, humidity detection and materials surface treatment, among others. The main obstacle for these applications is the generation of neutronic beams. Nuclear reactors, isotopic sources and particle accelerators are neutron generators commonly used. They share the disadvantages of being non-portable, and quite expensive. This work is mainly focused on the development of neutron generators suitable to the applications mentioned before, in which traditional generators are non-applicable. The main characteristics should be transportability and to be non-contaminating, which would allow in-situ tests. Plasma focus generators, which produce neutron pulses by thermonuclear fusion reactions, satisfy these requirements and are economically convenient. This last feature would assure competitively in the neutron sources market. (author)

Critical density and disruptions in α-heated thermonuclear Tokamak discharges

International Nuclear Information System (INIS)

Cotsaftis, M.; Firestone, M.; Wang, P.K.C.

1985-02-01

The study of existence of a critical density limit has been extended to the case of thermonuclear α-particle heated regime. To proceed, a 0-D model including sources and sinks affecting the evolution of ion and electron temperatures and of electron and α-particle densities with auxiliary neutral injected power has been developed. It is mainly shown when considering a Tokamak machine adapted for thermonuclear performances that, like in previous case, there is a critical density above which no other equilibrium point than 0 does exist. Temperatures then drop down the 0 past this critical value, leading to disruption. Analytic expression for critical density is given in terme of auxiliary projected power Psup(N). For Psup(N)=0, critical density value is low, but it increases fast enough for small Psup(N) to give a large safety margin once Psup(N) is moderate, much below the power required for reaching thermonuclear regime. So it is only at shutdown power periods that critical density can be crossed. But in this case, the heat content of particles in the discharge can significantly contribute to smooth out the temperature drop off. This typically operates up to the point where, due to change in magnetic islands configuration resulting from profile modification due to energy release at critical density crossing, heat transport doubles. Then on a fast thermal diffusion time scale, temperature drops now to a new equilibrium value, which can be made above the limiting value for which position control system of the plasma cannot forbid the plasma current to drop off itself, which is the important phenomenon of disruption. So on top of controls previously discussed, it is possible to use the α-particles themselves as a new preventive control against disruptions, making this phenomenon less dangerous for thermonuclear regime operation

Tritium inventory control--the experience with DT tokamaks and its relevance for future machines

International Nuclear Information System (INIS)

Bell, A.C.; Gentile, C.A.; Laesser, R.L.K.; Coad, J.P.

2003-01-01

At present, the commercial use of tritium is relatively small scale. The main source of supply is as a by-product of heavy water moderated fission reactors and the products are mainly discrete sources or tracers with activity typically in the GBq range. There are in general no restrictions on the use of tritium other than those, which would normally apply to the use of radioactive material. The future use of tritium as intermediate fuel for a fusion power plant series will involve an increase by several orders of magnitude in the industrial use of tritium and may increase concerns relating to safety, transport and waste disposal. In addition, the use of tritium in fusion power will be unable to be satisfied by current sources of supply and tritium production in future fusion power plants will be essential for the operation of the plants as well as for the start of new ones. Power plant studies have, however, shown that these issues can be satisfactorily addressed. In addition the values for clearance of tritiated materials in a number of countries are consistent with the low environmental impact of disposal of tritiated waste. There are, however, many practical operational and regulatory problems, which will need to be solved in the context of the experimental programmes. The current regulations for control and accountancy of tritium inventory, as applied internationally and in specific countries, are reviewed and their influence on the DT fuel cycle considered. The effect of safety case limits on the need for control of tritium inventory in TFTR, JET and ITER is analysed. The sensitivity of the fuel cycle to tritium inventory is considered. The experience of controlling tritium inventory in TFTR and JET is reviewed and the latest results from JET presented. This takes into account the limits and constraints, the differing requirements for tritium processing, in-vessel retention, the needs for waste management and decommissioning including detritiation, and

Italy, EURATOM and Early Research on Controlled Thermonuclear Fusion (1957-1962)

International Nuclear Information System (INIS)

Curli, Barbara

2017-01-01

This chapter traces the early origins of European collaboration in controlled thermonuclear fusion research, within the larger picture of Cold War nuclear policy in the late 1950s-early 1960s, and as a consequence of the signing of the EURATOM treaty in 1957. It then presents some preliminary findings on the Association contract which was signed in 1960 between EURATOM and Italy, in order to carry out research in controlled thermonuclear fusion at the then newly created 'Laboratori nazionali di Frascati', near Rome, within the framework of the Comitato Nazionale Energia Nucleare (CNEN), the Italian civilian nuclear energy agency.

Branched Lateral Tail Fiber Organization in T5-Like Bacteriophages DT57C and DT571/2 is Revealed by Genetic and Functional Analysis

Directory of Open Access Journals (Sweden)

Alla K. Golomidova

2016-01-01

Full Text Available The T5-like siphoviruses DT57C and DT571/2, isolated from horse feces, are very closely related to each other, and most of their structural proteins are also nearly identical to T5 phage. Their LTFs (L-shaped tail fibers, however, are composed of two proteins, LtfA and LtfB, instead of the single Ltf of bacteriophage T5. In silico and mutant analysis suggests a possible branched structure of DT57C and DT571/2 LTFs, where the LtfB protein is connected to the phage tail via the LtfA protein and with both proteins carrying receptor recognition domains. Such adhesin arrangement has not been previously recognized in siphoviruses. The LtfA proteins of our phages are found to recognize different host O-antigen types: E. coli O22-like for DT57C phage and E. coli O87 for DT571/2. LtfB proteins are identical in both phages and recognize another host receptor, most probably lipopolysaccharide (LPS of E. coli O81 type. In these two bacteriophages, LTF function is essential to penetrate the shield of the host’s O-antigens. We also demonstrate that LTF-mediated adsorption becomes superfluous when the non-specific cell protection by O-antigen is missing, allowing the phages to bind directly to their common secondary receptor, the outer membrane protein BtuB. The LTF independent adsorption was also demonstrated on an O22-like host mutant missing O-antigen O-acetylation, thus showing the biological value of this O-antigen modification for cell protection against phages.

D-T axicell magnet system for MFTF-α+T

International Nuclear Information System (INIS)

Srivastava, V.C.

1983-01-01

The configuration and design of the deuterium-tritium (D-T) axicell superconducting magnets for the Mirror Fusion Test Facility (MFTF-α+T) are described. The MFTF-α+T is an upgrade of the MFTF-B, with new end-plug magnets and a neutron-producing central D-T axicell section. The 4-m long axicell - its length defined by the 12-T peaks in the mirror field - is beam fueled and heated by two beam lines, each with four neutral beam injection ports. Two large superconducting coils (means diameter approx. 3.8 m) located at Z = +-2.40 m, in conjunction with a small copper coil located outside the test volume region, produce the 4.5-T mirror midplane field. This background field is augmented by two copper coils to create the 12-T peak mirror fields at Z = +-2 m. The central region of the axicell accommodates a 1-m-long, replaceable blanket test module. The length (4 m) of the axicell was chosen to provide relatively uniform neutron wall loading over the test module. In many respects, this axicell is less than full scale, but it could be viewed as a short section of a reactor, complete with the support systems and technologies associated with a mirror reactor. The peak field at the superconducting coils is 10.8 T. The coils employ hybrid superconducting winding - Nb 3 Sn conductor in the 8- to 12-T region and NbTi in the 0- to 8-T region. The winding is cryostable and is cooled by a 4.2 K liquid helium bath. The conductor design, the winding design, and the performance analyses for these superconducting coils are described

Atypical Thermonuclear Supernovae from Tidally Crushed White Dwarfs

International Nuclear Information System (INIS)

Rosswog, S.; Ramirez-Ruiz, E.; Hix, William Raphael

2008-01-01

Suggestive evidence has accumulated that intermediate mass black holes (IMBHs) exist in some globular clusters. Some stars will inevitably wander sufficiently close to the hole to suffer a tidal disruption. IMBHs can disrupt not only solar-type stars but also compact white dwarf stars. We investigate the fate of white dwarfs that approach the hole close enough to be disrupted and compressed to such an extent that explosive nuclear burning is triggered. Based on a precise modeling of the gas dynamics together with the nuclear reactions, it is argued that thermonuclear ignition is a natural outcome for white dwarfs of all masses passing well within the tidal radius. A good fraction of the star is accreted, yielding high luminosities that persist for up to a year. A peculiar, underluminous thermonuclear explosion accompanied by a soft X-ray transient signal would, if detected, be a compelling testimony for the presence of an IMBH

28. Zvenigorod conference on the plasma physics and controlled thermonuclear synthesis. Theses of reports

International Nuclear Information System (INIS)

2001-01-01

Theses of reports, presented at the 28th Conference on the plasma physics and controlled thermonuclear synthesis (Zvenigorod, 19-23 February 2001) are published. 246 reports were heard at the following sections: magnetic confinement, theory and experiments; inertial thermonuclear synthesis; plasma processes and physics of gas-discharge plasma; physical bases of plasma technologies. 17 reports had the summarizing character [ru

Nuclear Fusion Fuel Cycle Research Perspectives

International Nuclear Information System (INIS)

Chung, Hongsuk; Koo, Daeseo; Park, Jongcheol; Kim, Yeanjin; Yun, Sei-Hun

2015-01-01

As a part of the International Thermonuclear Experimental Reactor (ITER) Project, we at the Korea Atomic Energy Research Institute (KAERI) and our National Fusion Research Institute (NFRI) colleagues are investigating nuclear fusion fuel cycle hardware including a nuclear fusion fuel Storage and Delivery System (SDS). To have a better knowledge of the nuclear fusion fuel cycle, we present our research efforts not only on SDS but also on the Fuel Supply System (FS), Tokamak Exhaust Processing System (TEP), Isotope Separation System (ISS), and Detritiation System (DS). To have better knowledge of the nuclear fusion fuel cycle, we presented our research efforts not only on SDS but also on the Fuel Supply System (FS), Tokamak Exhaust Processing System (TEP), Isotope Separation System (ISS), and Detritiation System (DS). Our efforts to enhance the tritium confinement will be continued for the development of cleaner nuclear fusion power plants

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

ITER fuel cycle

International Nuclear Information System (INIS)

Leger, D.; Dinner, P.; Yoshida, H.

1991-01-01

Resulting from the Conceptual Design Activities (1988-1990) by the parties involved in the International Thermonuclear Experimental Reactor (ITER) project, this document summarizes the design requirements and the Conceptual Design Descriptions for each of the principal subsystems and design options of the ITER Fuel Cycle conceptual design. The ITER Fuel Cycle system provides for the handling of all tritiated water and gas mixtures on ITER. The system is subdivided into subsystems for fuelling, primary (torus) vacuum pumping, fuel processing, blanket tritium recovery, and common processes (including isotopic separation, fuel management and storage, and processes for detritiation of solid, liquid, and gaseous wastes). After an introduction describing system function and conceptual design procedure, a summary of the design is presented including a discussion of scope and main parameters, and the fuel design options for fuelling, plasma chamber vacuum pumping, fuel cleanup, blanket tritium recovery, and auxiliary and common processes. Design requirements are defined and design descriptions are given for the various subsystems (fuelling, plasma vacuum pumping, fuel cleanup, blanket tritium recovery, and auxiliary/common processes). The document ends with sections on fuel cycle design integration, fuel cycle building layout, safety considerations, a summary of the research and development programme, costing, and conclusions. Refs, figs and tabs

Comparison of DT neutron production codes MCUNED, ENEA-JSI source subroutine and DDT

Energy Technology Data Exchange (ETDEWEB)

Čufar, Aljaž, E-mail: aljaz.cufar@ijs.si [Reactor Physics Department, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Lengar, Igor; Kodeli, Ivan [Reactor Physics Department, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Milocco, Alberto [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Sauvan, Patrick [Departamento de Ingeniería Energética, E.T.S. Ingenieros Industriales, UNED, C/Juan del Rosal 12, 28040 Madrid (Spain); Conroy, Sean [VR Association, Uppsala University, Department of Physics and Astronomy, PO Box 516, SE-75120 Uppsala (Sweden); Snoj, Luka [Reactor Physics Department, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia)

2016-11-01

Highlights: • Results of three codes capable of simulating the accelerator based DT neutron generators were compared on a simple model where only a thin target made of mixture of titanium and tritium is present. Two typical deuteron beam energies, 100 keV and 250 keV, were used in the comparison. • Comparisons of the angular dependence of the total neutron flux and spectrum as well as the neutron spectrum of all the neutrons emitted from the target show general agreement of the results but also some noticeable differences. • A comparison of figures of merit of the calculations using different codes showed that the computational time necessary to achieve the same statistical uncertainty can vary for more than 30× when different codes for the simulation of the DT neutron generator are used. - Abstract: As the DT fusion reaction produces neutrons with energies significantly higher than in fission reactors, special fusion-relevant benchmark experiments are often performed using DT neutron generators. However, commonly used Monte Carlo particle transport codes such as MCNP or TRIPOLI cannot be directly used to analyze these experiments since they do not have the capabilities to model the production of DT neutrons. Three of the available approaches to model the DT neutron generator source are the MCUNED code, the ENEA-JSI DT source subroutine and the DDT code. The MCUNED code is an extension of the well-established and validated MCNPX Monte Carlo code. The ENEA-JSI source subroutine was originally prepared for the modelling of the FNG experiments using different versions of the MCNP code (−4, −5, −X) and was later extended to allow the modelling of both DT and DD neutron sources. The DDT code prepares the DT source definition file (SDEF card in MCNP) which can then be used in different versions of the MCNP code. In the paper the methods for the simulation of the DT neutron production used in the codes are briefly described and compared for the case of a

Brazilian programme for plasma physics and controlled thermonuclear fusion

International Nuclear Information System (INIS)

Chian, A.C.L.; Reusch, M.F.; Nascimento, I.C.; Pantuso-Sudano, J.

1992-01-01

A proposal for a National Programme of Plasma Physics and Controlled Thermonuclear Fusion in Brazil is presented, aimimg the dissemination of the researchers thought in plasma physics for the national authorities and the scientific community. (E.O.)

Fusion performances and alpha heating in future JET D-T plasmas

Energy Technology Data Exchange (ETDEWEB)

Balet, B; Cordey, J G; Gibson, A; Lomas, P; Stubberfield, P M; Thomas, P [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-07-01

The new pump divertor installed at JET should allow high performance pulses of a few seconds duration by both preventing the impurity influx and controlling the density evolution. The TRANSP code has been used in a predictive mode to assess the possible fusion performance of such plasmas fuelled with a 50:50 mixture of D and T, and the effect of alpha particles heating on Te and Ti. Several cases are considered: 50:50 D-T mix; 50:50 D-T mix, no C bloom; 50:50 D-T mix, VH phase, density control; 50:50 D-T mix, VH phase, density control, 6 Ma. The predictions show that if the the bloom and MHD instabilities can be controlled at higher plasma currents using a higher toroidal field to keep a reasonable beta value, then a higher fusion performance steady state plasma with Q{sub DT} superior to 2.5 should be possible. The alpha heating power of 4.9 MW would lead to a 74% increase in Te. 4 refs., 4 figs., 1 tab.

Analysis of induction phenomena in thermonuclear experiments

International Nuclear Information System (INIS)

Deeds, W.E.; Dodd, C.V.

1976-01-01

Many of the problems involving transients induced by changing currents in the large coils of thermonuclear machines are identical to those arising in nondestructive testing by eddy currents. There are three chief methods used for calculating such induction phenomena: analytical boundary-value solutions, relaxation or iteration techniques, and model experiments. Some of the results obtained by each of these methods are described below

Thermonuclear device

International Nuclear Information System (INIS)

Takano, Hirohisa; Nakamoto, Kazunari; Hanai, Satoshi.

1984-01-01

Purpose: To provide coils of high mechanical strength for use at the center of a torus type thermonuclear device. Constitution: A plurality of copper plates having cooling holes and bolt holes and insulation paper sheets of the same shape are prepared. The copper plate is different from the insulation paper sheet only in that the position-phase angle of the opening portion is larger by 15 - 30 0 . The copper plates and the insulation paper sheets are alternately stacked by a required number of turns while displacing the angle, and then clamped by bolts to form a mechanically strong coil with no metallurgical joining. Further, since the insulation paper sheets are not present in the radial direction and only one insulation paper sheet is inserted for each turn in the direction of the coil height, the space occupied by the coil can be decreased. According to this invention, the magnetic flux density at the center of the device can be increased as compared with the conventional case to thereby apply a higher voltage on the side of plasmas. (Moriyama, K.)

The extraordinarily beautiful physical principle of thermonuclear charge design (on the occasion of the 50th anniversary of the test of RDS-37 - the first Soviet two-stage thermonuclear charge)

Energy Technology Data Exchange (ETDEWEB)

Goncharov, German A [Russian Federal Nuclear Center ' All-Russian Scientific Research Institute of Experimental Physics' , Sarov, Nizhnii Novgorod Region (Russian Federation)

2005-11-30

On 22 November 1955, the Semipalatinsk test site saw the test of the first domestic two-stage thermonuclear RDS-37 charge. The charge operation was based on the principle of radiation implosion. The kernel of the principle consists in the radiation generated in a primary A-bomb explosion and confined by the radiation-opaque casing propagating throughout the interior casing volume and flowing around the secondary thermonuclear unit. The secondary unit experiences a strong compression under the irradiation, with a resulting nuclear and thermonuclear explosion. The RDS-37 explosion was the strongest of all those ever realized at the Semipalatinsk test site. It produced an indelible impression on the participants in the test. This document-based paper describes the genesis of the ideas underlying the RDS-37 design and reflects the critical moments in its development. The advent of RDS-37 was an outstanding accomplishment of the scientists and engineers of our country. (from the history of physics)

The extraordinarily beautiful physical principle of thermonuclear charge design (on the occasion of the 50th anniversary of the test of RDS-37 - the first Soviet two-stage thermonuclear charge)

International Nuclear Information System (INIS)

Goncharov, German A

2005-01-01

On 22 November 1955, the Semipalatinsk test site saw the test of the first domestic two-stage thermonuclear RDS-37 charge. The charge operation was based on the principle of radiation implosion. The kernel of the principle consists in the radiation generated in a primary A-bomb explosion and confined by the radiation-opaque casing propagating throughout the interior casing volume and flowing around the secondary thermonuclear unit. The secondary unit experiences a strong compression under the irradiation, with a resulting nuclear and thermonuclear explosion. The RDS-37 explosion was the strongest of all those ever realized at the Semipalatinsk test site. It produced an indelible impression on the participants in the test. This document-based paper describes the genesis of the ideas underlying the RDS-37 design and reflects the critical moments in its development. The advent of RDS-37 was an outstanding accomplishment of the scientists and engineers of our country. (from the history of physics)

A one-dimensional transport code for the simulation of D-T burning tokamak plasma

International Nuclear Information System (INIS)

Tone, Tatsuzo; Maki, Koichi; Kasai, Masao; Nishida, Hidetsugu

1980-11-01

A one-dimensional transport code for D-T burning tokamak plasma has been developed, which simulates the spatial behavior of fuel ions(D, T), alpha particles, impurities, temperatures of ions and electrons, plasma current, neutrals, heating of alpha and injected beam particles. The basic transport equations are represented by one generalized equation so that the improvement of models and the addition of new equations may be easily made. A model of burn control using a variable toroidal field ripple is employed. This report describes in detail the simulation model, numerical method and the usage of the code. Some typical examples to which the code has been applied are presented. (author)

Shock ignition of thermonuclear fuel: principles and modelling

International Nuclear Information System (INIS)

Atzeni, S.; Ribeyre, X.; Schurtz, G.; Schmitt, A.J.; Canaud, B.; Betti, R.; Perkins, L.J.

2014-01-01

Shock ignition is an approach to direct-drive inertial confinement fusion (ICF) in which the stages of compression and hot spot formation are partly separated. The fuel is first imploded at a lower velocity than in conventional ICF. Close to stagnation, an intense laser spike drives a strong converging shock, which contributes to hot spot formation. Shock ignition shows potentials for high gain at laser energies below 1 MJ, and could be tested on the National Ignition Facility or Laser MegaJoule. Shock ignition principles and modelling are reviewed in this paper. Target designs and computer-generated gain curves are presented and discussed. Limitations of present studies and research needs are outlined. (special topic)

Commissioning of a DT fusion reactor without external supply of tritium

International Nuclear Information System (INIS)

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

2001-01-01

Commissioning of a DT fusion reactor without external supply of tritium is discussed. The DD reactions in a DT-oriented fusion reactor with external power injection by neutral beams produce tritium and neutrons. Tritium produced by the DD reaction together with that produced in the blanket by the 2.45 MeV neutron is re-circulated into the plasma. Then, the DT reaction rate increases gradually, as tritium concentration in plasma builds up towards the level of nominal operation. Time required to reach the nominal operational condition, i.e. 50 % tritium in plasma, is estimated with assumptions based on a model of fusion power plant. As a result, the start-up period of a DT fusion reactor without external supply of tritium is estimated to be approximately 55 days, with the plasma parameters of CREST having a high performance blanket and tritium processing systems. Major factors to determine the start-up period are DD and DT reaction rates, net tritium breeding gain of the plant and dead inventory in/on facing materials. Elimination of a constraint for fusion reactor deployment and operation without any tritium transportation in and out of plant through its entire life may be possible. (author)

The LOFT perspective on neutron star thermonuclear bursts

DEFF Research Database (Denmark)

in ’t Zand, J.J.M.; Altamirano, D.; Ballantyne, D. R.

This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of thermonuclear X-ray bursts on accreting neutron stars. For a summary, we refer to the paper....

The chicken B-cell line DT40 proteome, beadome and interactomes

Directory of Open Access Journals (Sweden)

Johanna S. Rees

2015-06-01

Full Text Available In developing a new quantitative AP-MS method for exploring interactomes in the chicken B-cell line DT40, we also surveyed the most abundant proteins in this organism and explored the likely contaminants that bind to a variety of affinity resins that would later be confirmed quantitatively [1]. We present the ‘Top 150 abundant DT40 proteins list’, the DT40 beadomes as well as protein interaction lists for the Phosphatidyl inositol 5-phosphate 4-kinase 2β and Fanconi anaemia protein complexes.

Tokamak hybrid thermonuclear reactor for the production of fissionable fuel and electric power

International Nuclear Information System (INIS)

Velikhov, E.P.; Glukhikh, V.A.; Gur'ev, V.V.

1978-01-01

The results of feasibility studies of a tokamak- based hybrid reactor concept are presented. The system selected has a D-T plasma volume of 575 m 3 with additional plasma heating by injection of fast neutral particles. The method of heating makes it possible to achieve an economical two-component tokamak regime at ntau=(4-6)x10 13 sxcm -3 , i e. far below the Lawson criterion. Plasma and vacuum chamber are surrounded by a blanket where fissionable plutonium is produced and heat transformed into electric power is generated. Major plasma-neutron-physical characteristics of the 6905 MWth (2500 MWe) reactor and its electromagnetic system are presented. Evaluations show that the hybrid reactor can produce about 800 kg of Pu per 1GWth/yr as compared to 70-150 kg of Pu for fast breeder reactors. The increased Pu production rate is the major merit of the concept promising for both power generation and fuelling thermal fission reactions

Measurements of fuel and ablator ρR in Symmetry-Capsule implosions with the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Gatu Johnson, M., E-mail: gatu@psfc.mit.edu; Frenje, J. A.; Li, C. K.; Séguin, F. H.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Bionta, R. M.; Casey, D. T.; Caggiano, J. A.; Hatarik, R.; Khater, H. Y.; Sayre, D. B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Knauer, J. P.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Herrmann, H. W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kilkenny, J. D. [General Atomics, San Diego, California 92186 (United States)

2014-11-15

The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility (NIF) measures the neutron spectrum in the energy range of 4–20 MeV. This paper describes MRS measurements of DT-fuel and CH-ablator ρR in DT gas-filled symmetry-capsule implosions at the NIF. DT-fuel ρR's of 80–140 mg/cm{sup 2} and CH-ablator ρR's of 400–680 mg/cm{sup 2} are inferred from MRS data. The measurements were facilitated by an improved correction of neutron-induced background in the low-energy part of the MRS spectrum. This work demonstrates the accurate utilization of the complete MRS-measured neutron spectrum for diagnosing NIF DT implosions.

Correlation of DT and DD fusion neutron damage in silicon surface barrier detector

International Nuclear Information System (INIS)

Iida, Toshiyuki; Sueyoshi, Yasuhiro; Sunarno; Takahashi, Akito

1994-01-01

In order to examine the correlation of DT and DD fusion neutron damage in Si, a silicon surface barrier detector (Si-SBD) was irradiation with neutrons from a deuteron accelerator. The leakage current increased proportionally with neutron fluence, which determined the neutron damage constant for the Si-SBD. The correlation factor of the DT and DD neutron damage in the Si-SBD was determined from the ratio of the DT and DD neutron damage constants and was found to be 2.3. We also calculated the rate of DT and DD neutron displacement damage for Si by using the TRIM-90 computer program and actual data on neutron reactions in the Si-SBD. The correlation factor of DT and DD neutron damage from the calculation agreed with that from the Si-SBD irradiation experiment. (author)

Simulations of DT experiments in TFTR

International Nuclear Information System (INIS)

Budny, R.; Bell, M.G.; Biglari, H.; Bitter, M.; Bush, C.; Cheng, C.Z.; Fredrickson, E.; Grek, B.; Hill, K.W.; Hsuan, H.; Janos, A.; Jassby, D.L.; Johnson, D.; Johnson, L.C.; LeBlanc, B.; McCune, D.C.; Mikkelsen, D.R.; Park, H.; Ramsey, A.T.; Sabbagh, S.A.; Scott, S.; Schivell, J.; Strachan, J.D.; Stratton, B.C.; Synakowski, E.; Taylor, G.; Zarnstorff, M.C.; Zweben, S.J.

1991-12-01

A transport code (TRANSP) is used to simulate future deuterium-tritium experiments (DT) in TFTR. The simulations are derived from 14 TFTR DD discharges, and the modeling of one supershot is discussed in detail to indicate the degree of accuracy of the TRANSP modeling. Fusion energy yields and α-particle parameters are calculated, including profiles of the α slowing down time, average energy, and of the Alfven speed and frequency. Two types of simulations are discussed. The main emphasis is on the DT equivalent, where an equal mix of D and T is substituted for the D in the initial target plasma, and for the D O in the neutral-beam injection, but the other measured beam and plasma parameters are unchanged. This simulation does not assume that α heating will enhance the plasma parameters, or that confinement will increase with T. The maximum relative fusion yield calculated for these simulations is Q DT ∼ 0.3, and the maximum α contribution to the central toroidal β is β α (0) ∼ 0.5%. The stability of toroidicity-induced Alfven eigenmodes (TAE) and kinetic ballooning modes (KBM) is discussed. The TAE mode is predicted to become unstable for some of the equivalent simulations, particularly after the termination of neutral beam injection. In the second type of simulation, empirical supershot scaling relations are used to project the performance at the maximum expected beam power. The MHD stability of the simulations is discussed

D-T radiation effects on TFTR diagnostics

International Nuclear Information System (INIS)

Ramsey, A.T.

1994-10-01

For a 50%-50% deuterium-tritium plasma, the neutron production is 80x higher and the total energy release is 200x higher than the same plasma composed only of deuterium. With this increase in radiation, diagnostics which see only negligible amounts of noise during DD operation may find themselves overwhelmed during DT. The neutrons are not only more numerous, but have 6x as much energy, which causes the calculated 2.4x increase in the gamma flux per neutron near TFTR. We report here the effects of this increased radiation on the TFTR diagnostic set. The most noticeable effects are luminescence and transmission losses in fiber optic signal cables. In addition, a plastic fiber near the torus became unusably opaque after a few DT discharges. Silicon detectors show signs of neutron interactions as well as gamma response, and microchannel electron multipliers show an increased background due to the gamma flux. Bolometers show n and γ heating, and the Thomson scattering intensifier gate spark gap was unreliable until the gas pressure was adjusted. All of these effects were anticipated, and in some cases shielding or compensation techniques were used. Compensation fibers work satisfactorily at these radiation levels, and the rapid fall-off of the radiation as one moves away from the machine makes relocation of fibers and other sensitive components very useful. Conventional shielding designs worked when streaming through signal penetrations was properly dealt with. In coming DT campaigns and the generation of new tokamaks, such problems will be more severe. JET anticipates higher dose levels per shot during DT; TPX has 1000 s pulses and ITER presents a particularly difficult challenge. We shall discuss the implications of our results for diagnostics on these machines

Tomography of laser fusion plasmas

International Nuclear Information System (INIS)

Ceglio, N.M.

1977-01-01

Experimental programs exist in a number of laboratories throughout the world to test the feasibility of using powerful laser systems to drive the implosion of hydrogen isotope fuel to thermonuclear burn conditions. In a typical experiment multiple laser beams are focused onto a glass microshell (typically 50 μm to 200 μm diameter) filled with an equimolar D-T gas mixture. X-ray and particle emissions from the target provide important information about the hydrodynamic implosion of the glass shell and the associated compression and heating of the D-T fuel. Standard diagnostics for imaging such emissions are the grazing incidence reflection (GIR) x-ray microscope and the pinhole camera. Recently, a particular coded imaging technique, Zone Plate Coded Imaging (ZPCI), has been successfully used for x-ray and particle microscopy of laser fusion plasmas. ZPCI is highly attractive for investigating laser produced plasmas because it possesses a tomographic capability not shared by either the GIR or pinhole imaging techniques. This presentation provides a brief discussion of the tomographic potential of ZPCI. In addition, the first tomographic x-ray images (tomographic resolution approximately 74 μm) of a laser produced plasma are presented

Report based on DT/7 questionnaire

DEFF Research Database (Denmark)

Sørensen, Annette Balle; Kruse, Filip; Thøgersen, Jørn

DT/7-D4 is concerned with which types of communication within academic communities are essential viewed in respect of preservation. The central product is a presentation and an analysis of a questionnaire deployed to researchers at Aarhus University....

Atomic and molecular physics of controlled thermonuclear fusion

International Nuclear Information System (INIS)

Joachain, C.J.; Post, D.E.

1983-01-01

This book attempts to provide a comprehensive introduction to the atomic and molecular physics of controlled thermonuclear fusion, and also a self-contained source from which to start a systematic study of the field. Presents an overview of fusion energy research, general principles of magnetic confinement, and general principles of inertial confinement. Discusses the calculation and measurement of atomic and molecular processes relevant to fusion, and the atomic and molecular physics of controlled thermonuclear research devices. Topics include recent progress in theoretical methods for atomic collisions; current theoretical techniques for electron-atom and electronion scattering; experimental aspects of electron impact ionization and excitation of positive ions; the theory of charge exchange and ionization by heavy particles; experiments on electron capture and ionization by multiply charged ions; Rydberg states; atomic and molecular processes in high temperature, low-density magnetically confined plasmas; atomic processes in high-density plasmas; the plasma boundary region and the role of atomic and molecular processes; neutral particle beam production and injection; spectroscopic plasma diagnostics; and particle diagnostics for magnetic fusion experiments

Power supply for magnetic coils in thermonuclear devices

International Nuclear Information System (INIS)

Shimada, Ryuichi; Tamura, Sanae; Kishimoto, Hiroshi.

1981-01-01

Purpose: To decrease the load fluctuations in an external power supply, as well as to increase the operation efficiency capacity of thermonuclear devices. Constitution: Electrical power with the same frequency as that of a dynamo generator is supplied by a power supply-driving power source including a frequency converter and the like to DC converters for driving plasma-exciting and -controlling coils. At the same time, the electrical power from the frequency converter is supplied to the dynamo generator with flywheel to add accumulate energies to the EC converters. Accordingly, the energy for the great power pulses in a short time comprises the sum of the energy supplied from the dynamo generator with flywheel and the energy supplied continuously from the outside to eliminate the need of providing a stand-by period for the re-acceleration of the dynamo generator with flywheel even if the scale of the thermonuclear device is enlarged and energy consumed in one cycle is increased, whereby the decrease in the operation efficiency can be prevented and the capacity of the flywheel can be reduced. (Yoshino, Y.)

XXXII Zvenigorod conference on the plasma physics and controlled thermonuclear synthesis. Theses of reports

International Nuclear Information System (INIS)

2005-01-01

Theses of the reports, presented at the XXXII International conference on the plasma physics and controlled thermonuclear synthesis (Zvenigorod, 14-18 February 2005) are published. The total number of reports is 322, including 16 summarizing ones. The other reports are distributed by the following sections: magnetic confinement of high-temperature plasma (88 reports), inertial thermonuclear fusion (65), physical processes in low-temperature plasma (99) and physical bases of the plasma and beam technologies (54) [ru

Measurement of TFTR D-T radiation shielding efficiency

International Nuclear Information System (INIS)

Kugel, H.W.; Ascione G.; Elwood, S.

1994-01-01

High power D-T fusion reactor designs presently exhibit complex geometric and material density configurations. Simulations of the radiation shielding required for safe operation and full compliance with all regulatory requirements must include sufficient margin to accommodate uncertainties in material properties and distributions, uncertainties in the final configurations, and uncertainties in approximations employing the homogenization of complex geometries. Measurements of radiation shielding efficiency performed in a realistic D-T tokamak environment can provide empirical guidance for simulating safe, efficient, and cost effective shielding systems for future high power fusion reactors. In this work, the authors present the results of initial measurements of the TFTR radiation shielding efficiency during high power D-T operations with record neutron yields. The TFTR design objective is to limit the total dose-equivalent at the nearest PPPL property lines from all radiation pathways to 10 mrem per calendar year. Compliance with this design objective over a calendar year requires measurements in the presence of typical site backgrounds of about 80 mrem per year

A new noninvasive device for measuring central ejection dP/dt mathematical foundation of cardiac dP/dt measurement using a model for a collapsible artery.

Science.gov (United States)

Gorenberg, Miguel; Rotztein, Hector; Marmor, Alon

2009-03-01

We have developed a novel non-invasive device for the measurement of one of the most sensitive indices of myocardial contractility as represented by the rate of increase of intraventricular pressure (left ventricular dP/dt and arterial dP/dt performance index (dP/dt(ejc)). Up till now, these parameters could be obtained only by invasive catheterization methods. The new technique is based on the concept of applying multiple successive occlusive pressures on the brachial artery from peak systole to diastole using a inflatable cuff and plotting the values against time intervals that leads to the reconstruction of the central aortic pressure noninvasively. The following describes the computer simulator developed for providing a mathematical foundation of the new sensor. At the core of the simulator lies a hemodynamic model of the blood flow on an artery under externally applied pressure. The purpose of the model is to reproduce the experimental results obtained in studies on patients (Gorenberg et al. in Cardiovasc Eng: 305-311, 2004; Gorenberg et al. in Emerg med J 22 (7): 486-489, 2005) and a animal model where ischemia resulted from balloon inflation during coronary catheterization (Gorenberg and Marmor in J Med Eng Technol, 2006) and to describe correlations between the dP/dt(ejc) and other hemodynamic variables. The model has successfully reproduced the trends observed experimentally, providing a solid in-depth understanding of the hemodynamics involved in the new measurement. A high correlation between the dP/dt(ejc) and the rate of pressure rise in the aorta during the ejection phase was observed. dP/dt(ejc) dependence on other hemodynamic parameters was also investigated.

The Genome of the Chicken DT40 Bursal Lymphoma Cell Line

DEFF Research Database (Denmark)

Molnar, Janos; Poti, Adam; Pipek, Orsolya

2014-01-01

The chicken DT40 cell line is a widely used model system in the study of multiple cellular processes due to the efficiency of homologous gene targeting. The cell line was derived from a bursal lymphoma induced by avian leukosis virus infection. In this study we characterized the genome of the cell...... chicken genomes and the Gallus gallus reference genome, we found no unique mutational processes shaping the DT40 genome except for a mild increase in insertion and deletion events, particularly deletions at tandem repeats. We mapped coding sequence mutations that are unique to the DT40 genome; mutations...

Issues for the electric utilities posed by DT tokamak fusion powerplants

International Nuclear Information System (INIS)

Roth, J.R.

1990-01-01

The DT tokamak is the mainline approach to magnetic fusion energy in all industrialized countries with a major commitment to fusion research. It achieved this status largely through historical accident and not as the result of considered choice among alternatives. After twenty-five years of intensive tokamak research, it is appropriate to ask whether the path down which the tokamak concept is leading the fusion community is the way to an acceptable powerplant for the electric utilities, or an aberration which should be replaced with an approach more promising in the long term. Issues surrounding the DT tokamak can be grouped in three broad areas: physics; safety/environmental; and engineering/economic. In addition to these problems, detailed engineering design studies of DT tokamak fusion powerplants over a twenty year period have revealed a number of additional problems. Most of thee are related to the presence of tritium and energetic neutron fluxes, which tend to make the cost of electricity of DT tokamaks higher than that of fossil or fission powerplants. These safety and economic issues of the DT tokamak powerplant also appear to be intractable, and have not been made to go away by twenty years of progressively more detailed and extensive engineering design studies

Thermonuclear device

International Nuclear Information System (INIS)

Suzuki, Shohei.

1980-01-01

Purpose: To improve the plasma confining efficiency in a thermonuclear device having magnet coils using super-conducting wires by decreasing the uneven magnetic field resulted from current supply terminals and wirings. Constitution: Current introduction terminals of magnet coils using superconducting wires are short circuitted with a superconducting short circuit wire. Upon supplying current to the coils, the resistance of the coils is rendered superconductive and the resistance of the short circuit wire is rendered normally conductive heated by a heater and the switch is closed. In this case, most parts of the current are flown through the resistance of the coils and the switch is opened when the current arrives at a predetermined value to render the resistance of the short circuit wire superconductive. Then, the current transfers from the thyristor power source to the resistance of the short circuit wire, whereby the resistance of the coils and that of the short circuit wire from a permanent current loop. In this conditions, since current flows through the short circuit wire and the coils and not to the current introduction terminals, no uniform magnetic field is generated. (Kawakami, Y.)

Thermonuclear device

International Nuclear Information System (INIS)

Honda, Takuro; Maki, Koichi.

1997-01-01

The present invention provides a thermonuclear device, in which integrity of a measuring device is kept, the reactor wall temperature and wear of armour materials are monitored accurately even under intense radiation rays, so that the flow rate of coolants and plasma power can be controlled by using the signals. Infrared rays generated from the surface of the armour materials disposed on a first wall are detected to measure the reactor wall temperature. Coolant flow rate and plasma power are controlled based on the obtained reactor wall temperature. In addition, infrared rays generated from the back of the armour materials are detected to obtain the surface temperature in order to avoid intense radiation rays from plasmas. The coolant flow rate and the plasma power are controlled based on the obtained temperature on the surface of the reactor thereby controlling the temperature of the first wall and the armour material to 300degC or lower in a case of the first wall made of stainless steel and 1000degC or lower in a case of the armour material made of graphite. (I.S.)

Synthetic fuels and fusion

Energy Technology Data Exchange (ETDEWEB)

Fillo, J A; Powell, J; Steinberg, M [Brookhaven National Lab., Upton, NY (USA)

1981-03-01

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. equal to 40-60% and hydrogen production efficiencies by high temperature electrolysis of approx. equal to 50-70% 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.

Production of Medical isotope Technecium-99 from DT Fusion neutrons

Science.gov (United States)

Boguski, John; Gentile, Charles; Ascione, George

2011-10-01

High energy neutrons produced in DT fusion reactors have a secondary application for use in the synthesis of valuable man-made isotopes utilized in industry today. One such isotope is metastable Technecium-99 (Tc99m), a low energy gamma emitter used in ~ 85% of all medical imaging diagnostics. Tc99m is created through beta decay of Molybdenum-99 (Mo99), which itself has only a 66 hour half-life and must be created from a neutron capture by the widely available and stable isotope Molydenum-98. Current worldwide production of Tc99m occurs in just five locations and relies on obtaining the fission byproduct Mo99 from highly enriched Uranium reactors. A Tc99m generator using DT fusion neutrons, however, could potentially be operated at individual hospitals and medical facilities without the use of any fissile material. The neutron interaction of the DT neutrons with Molybdenum in a potential device geometry was modeled using Monte Carlo neutron transport code MCNP. Trial experiments were also performed to test the viability of using DT neutrons to create ample quantities of Tc99m. Modeling and test results will follow.

Experimental measurements of the 15O(alpha,gamma)19Ne reaction rate and the stability of thermonuclear burning on accreting neutron stars

International Nuclear Information System (INIS)

Fisker, J; Tan, W; Goerres, J; Wiescher, M; Cooper, R

2007-01-01

Neutron stars in close binary star systems often accrete matter from their companion stars. Thermonuclear ignition of the accreted material in the atmosphere of the neutron star leads to a thermonuclear explosion which is observed as an X-ray burst occurring periodically between hours and days depending on the accretion rate. The ignition conditions are characterized by a sensitive interplay between the accretion rate of the fuel supply and its depletion rate by nuclear burning in the hot CNO cycle and the rp-process. For accretion rates close to stable burning the burst ignition therefore depends critically on the hot CNO breakout reaction 15 O(α, γ) 19 Ne that regulates the flow between the hot CNO cycle and the rapid proton capture process. Until recently, the 15 O(α, γ) 19 Ne reaction rate was not known experimentally and the theoretical estimates carried significant uncertainties. In this paper we perform a parameter study of the uncertainty of this reaction rate and determine the astrophysical consequences of the first measurement of this reaction rate. Our results corroborate earlier predictions and show that theoretically burning remains unstable up to accretion rates near the Eddington limit, in contrast to astronomical observations

CM-244 as multiplier and breeder in a ThO/sub 2/ hybrid blanket driven by a (D,T) source

International Nuclear Information System (INIS)

Sahin, S.; Al-Kusayer, T.A.

1986-01-01

The safeguard aspects of Cm-244 - a nuclear waste product in LWRs - in a cylindrical hybrid blanket, driven by a (D,T) fusion neutron source have been analyzed. Cm-244 is investigated for two different applications: 1) as a neutron multiplier between the first wall and the fuel zone in a blanket with ThO/sub 2/; and 2) as a component of the mixed fuel, ThO/sub 2/-Cm/sup 244/O/sub 2/, used for power flattening in a hybrid blanket. The calculations show that a relatively small driven with 100 MW/sub th/ fusion power could produce about 5 kg/year Cm-245, enough to provide nuclear fuel for up to 50 explosives. The study suggests an extension of the safe-guarding regulations prior to the commercial introduction of fusion reactors in the energy market

Fabrication of an alumina torus for thermonuclear fusion containment

International Nuclear Information System (INIS)

Hauth, W.E.; Blake, R.D.; Dickinson, J.M.; Rutz, H.L.; Stoddard, S.D.

1978-05-01

A 235-cm-diam torus has been fabricated for plasma containment during thermonuclear fusion experiments. This 30-cm-diam torus consists of sixty 99.5%-alumina segments, 80% of which are assembled by forming vacuum-tight ceramic-to-ceramic seals. Selection of sealing materials and techniques are discussed

Feasibility studies of thermonuclear neutron capture synthesis of SHE

International Nuclear Information System (INIS)

Meldner, H.W.

1978-01-01

A variety of thermonuclear neutron sources and neutron capture targets were investigated for their potential of allowing signigicant production of heavy, perhaps superheavy, isotopes. The neutron sources considered range from inertial confinement microexplosives to (underground) macroexplosives. Optimal capture targets appear to be composites containing uranium and protactinium. 1 figure

Thermonuclear fusion by laser

International Nuclear Information System (INIS)

Delpech, J.-F.; Fabre, Edouard.

1978-01-01

This paper is intended to describe the principle of inetia containment by laser and the research effort undertaken for this purpose. After having enumerated the principal thermonuclear reactions useful for fusion, the authors derive the rhoR criterion that characterizes inertia containment, as well as the Lawson criterion in the case of magnetic containment. The main physics problems involved in inertia containment by laser are enunciated and the article ends with a review of means resorted to in France and abroad for studying this problem. This review also reports C.N.R.S. bustling in this field, within the scope of competence of G.I.L.M. (Groupement de Recherches Coordonnees sur l'Interaction Laser-Matiere = Group for coordinated investigation of matter-laser interaction) established in Paris at the Ecole Polytechnique [fr

What's D&T For? Gathering and Comparing the Values of Design and Technology Academics and Trainee Teachers

Science.gov (United States)

Hardy, Alison

2015-01-01

Some who read and research about Design & Technology (D&T) would say that the concept of value is key to understanding and defining D&T. Closer inspection reveals though that there are two ways in which values are defined in D&T: how values are taught and learnt about in D&T to use them to make judgments in D&T lessons, and…

DT simulation of ICRF heated supershots in TFTR using TRANSP

International Nuclear Information System (INIS)

Goldfinger, R.C.; Batchelor, D.B.; Phillips, C.K.; Budny, R.; Hammett, G.W.; Hosea, J.C.; McCune, D.M.; Stevens, J.E.; Wilson, J.R.

1993-01-01

The principal goal of ion cyclotron range of frequency (ICRF) heating on the Tokamak Fusion Test Reactor (TFTR) is to enhance plasma performance during the deuterium-tritium (DT) physics phase of operations. Strongly centralized ICRF heating may play a critical role in obtaining high Q DT and high β α operation in TFTR, as well as in future fusion reactors. ICRF heating of a dilute minority species leads to the formation of an energetic ion population that, in turn, provides strong central electron heating. The corresponding rise in the central electron temperature translates into an increase in the slowing-down time of either neutral beam or alpha particles in the discharge. Preliminary DT simulations of the experimental results in deuterium-deuterium (DD) plasmas performed with the TRANSP code are presented in this paper

Muon cycling rate in D/T mixture including doubly muonic molecule formation

Directory of Open Access Journals (Sweden)

M. R. Eskandari

2002-06-01

Full Text Available   In the present work, the fundamental behavior of four body molecule formations of pt μμ , pd μμ , dt μμ , tt μμ , and pp μμ in a D/T fusion are considered. Their higher fusion rate, specially the available data for dt μμ , encouraged us to study the muon cycling rate in D/T fusion in the temperature range of (100-1400 K, density and deuterium-tritium concentration ratio. For this purpose, various values for the doubly muonic molecule formation are chosen and with the comparison to the experimental results, the doubly muonic formation rate of 109 s-1 is predicted theoretically. Our calculated cycling rate has shown that having not considered the doubly muonic formation in previous calculations had made no serious changes in the previously calculated values.

HYPERFUSE: a hypervelocity inertial confinement system for fusion energy production and fission waste transmutation

International Nuclear Information System (INIS)

Makowitz, H.; Powell, J.R.; Wiswall, R.

1980-01-01

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from a LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs, 90 Sr, 129 I, 99 Tc, etc. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n,2n), (n,α), (n,γ), etc.) that convert the long-lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product. The transmutation parametric studies conclude that the design of the hypervelocity projectiles should emphasize the achievement of high densities in the transmutation regions (greater than the DT fusion fuel density), as well as the DT ignition and burn criterion (rho R = 1.0 to 3.0) requirements. These studies also indicate that masses on the order of 1.0 g at densities of rho greater than or equal to 500.0 g/cm 3 are required for a practical fusion-based fission product transmutation system

The international thermonuclear reactor (ITER)

International Nuclear Information System (INIS)

Fowler, T.K.; Henning, C.D.

1987-01-01

Four governmental groups, representing Europe, Japan, USSR and U.S. met in March 1987 to consider a new international design of a magnetic fusion device for the 1990's. An interim group was appointed. The author gives a brief synopsis of what might be thought of as a draft charter. The starting point is the objective of the ITER device, which is summarized as demonstrating both scientific and technical feasibility of fusion. The paper presents an update on the current thinking and technical aspects for the International Thermonuclear Experimental Reactor (ITER). This covers not only what is happening in the U.S. but also some reports of preliminary thinking of the last technical work that occurred in Vienna

Radionuclide left ventricular dV/dt for the assessment of cardiac function in patients with coronary disease.

Science.gov (United States)

Bianco, J A; Makey, D G; Laskey, W K; Shafer, R B

1979-01-01

To investigate potential uses of left-ventricular (LV) systolic ejection rate (LV dV/dt) in the evaluation of LV function, we examined the effect of exercise, angiotensin, and leg raising on LV ejection fraction and LV dV/dt in patients with coronary-artery disease. The following observations were made: a) LV ejection fraction and dV/dt changed proportionately, but in opposite directions, during supine exercise; b) LV ejection fraction and dV/dt decreased to a similar extent during angiotensin infusions; and c) LV ejection fraction and dV/dt were unchanged by leg raising. The changes in peak and mean LV dV/dt were similar. Regardless of the physiologic state, peak LV dV/dt occurred during the first third of systole. These data imply that in this population there were no specific advantages of LV dV/dt over LV ejection fraction in the evaluation of LV performance.

Radionuclide left ventricular dV/dt for the assessment of cardiac function in patients with coronary disease

International Nuclear Information System (INIS)

Bianco, J.A.; Makey, D.G.; Laskey, W.K.; Shafer, R.B.

1979-01-01

To investigate potential uses of left-ventricular (LV) systolic ejection rate (LV dV/dt) in the evaluation of LV function, we examined the effect of exercise, angiotensin, and leg raising on LV ejection fraction and LV dV/dt in patients with coronary-artery disease. The following observations were made: (a) LV ejection fraction and dV/dt changed proportionately, but in opposite directions, during supine exercise; (b) LV ejection fraction and dV/dt decreased to a similar extent during angiotensin infusions; and (c) LV ejection fraction and dV/dt were unchanged by leg raising. The changes in peak and mean LV dV/dt were similar. Regardless of the physiologic state, peak LV dV/dt occurred during the first third of systole. These data imply that in this population there were no specific advantages of LV dV/dt over LV ejection fraction in the evaluation of LV performance

Simulation of the dynamics of sausage development in a z pinch with a high rate of thermonuclear heat production

International Nuclear Information System (INIS)

Vikhrev, V.V.; Rozanova, G.A.

1993-01-01

The development of the sausage instability in a z pinch is accompanied by the formulation of a high-temperature plasma. This high-temperature region initiates a wave of thermonuclear burning propagating along the pinch. A numerical solution of the MHD equations has been carried out, taking into account plasma energy losses through radiation and thermonuclear heating. Results of calculations on the growth of the sausage instability are presented for ρr = 0.23 g/cm 2 . It is accompanied by the development of a stable wave of thermonuclear burning. 12 refs., 4 figs

Thermonuclear model for γ-ray bursts

International Nuclear Information System (INIS)

Woosley, S.E.

1981-01-01

The evolution of magnetized neutron stars with field strengths of approx. 10 12 gauss that are accreting mass onto kilometer-sized polar regions at a rate of approx. 13 M 0 yr -1 is examined. Based on the results of one-dimensional calculations, one finds that stable hydrogen burning, mediated by the hot CNO-cycle, will lead to a critical helium mass in the range 10 20 to 10 22 g km -2 . Owing to the extreme degeneracy of the electron gas providing pressure support, helium burning occurs as a violent thermonuclear runaway which may propagate either as a convective deflagration (Type I burst) or as a detonation wave (Type II burst). Complete combustion of helium into 56 Ni releases from 10 38 to 10 40 erg km -2 and pushes hot plasma with β > 1 above the surface of the neutron star. Rapid expansion of the plasma channels a substantial fraction of the explosion energy into magnetic field stress. Spectral properties are expected to be complex with emission from both thermal and non-thermal processes. The hard γ-outburst of several seconds softens as the event proceeds and is followed by a period, typically of several minutes duration, of softer x-ray emission as the subsurface ashes of the thermonuclear explosion cool. In this model, most γ-ray bursts currently being observed are located at a distance of several hundred parsecs and should recur on a timescale of months to centuries with convective deflagrations (Type I bursts) being the more common variety. An explanation for Jacobson-like transients is also offered

Global Genomic Epidemiology of Salmonella enterica Serovar Typhimurium DT104

DEFF Research Database (Denmark)

Leekitcharoenphon, Pimlapas; Hendriksen, Rene S.; Le Hello, Simon

2016-01-01

It has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella enterica serovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. We used whole-genome sequencing (WGS) and temporally struc...

Uniform DT 3T burn: computations and sensitivities

Energy Technology Data Exchange (ETDEWEB)

Vold, Erik [Los Alamos National Laboratory; Hryniw, Natalia [Los Alamos National Laboratory; Hansen, Jon A [Los Alamos National Laboratory; Kesler, Leigh A [Los Alamos National Laboratory; Li, Frank [Los Alamos National Laboratory

2011-01-27

A numerical model was developed in C to integrate the nonlinear deutrium-tritium (DT) burn equations in a three temperature (3T) approximation for spatially uniform test problems relevant to Inertial Confinement Fusion (ICF). Base model results are in excellent agreement with standard 3T results. Data from NDI, SESAME, and TOPS databases is extracted to create fits for the reaction rate parameter, the Planck opacity, and the coupling frequencies of the plasma temperatures. The impact of different fits (e.g., TOPS versus SESAME opacity data, higher order polynomial fits ofNDI data for the reaction rate parameter) were explored, and sensitivity to several model inputs are presented including: opacity data base, Coulomb logarithm, and Bremsstrahlung. Sensitivity to numerical integration time step size, and the relative insensitivity to the discretized numerics and numerical integration method was demonstrated. Variations in the IC for densities and temperatures were explored, showing similar DT burn profiles in most cases once ignition occurs. A coefficient multiplying the Compton coupling term (default, A = 1) can be adjusted to approximate results from more sophisticated models. The coefficient was reset (A = 0.4) to match the maximum temperatures resulting from standard multi-group simulations of the base case test problem. Setting the coefficient to a larger value, (A = 0.6) matches maximum ion temperatures in a kinetic simulation of a high density ICF-like regime. Matching peak temperatures does not match entire temperature-time profiles, indicating the Compton coefficient is density and time dependent as the photon distribution evolves. In the early time burn during the ignition of the DT, the present model with modified Compton coupling provides a very simple method to obtain a much improved match to the more accurate solution from the multi-group radiation model for these DT burn regimes.

Thermonuclear ignition in the next generation tokamaks

International Nuclear Information System (INIS)

Johner, J.

1989-04-01

The extrapolation of experimental rules describing energy confinement and magnetohydrodynamic - stability limits, in known tokamaks, allow to show that stable thermonuclear ignition equilibria should exist in this configuration, if the product aB t x of the dimensions by a magnetic-field power is large enough. Quantitative application of this result to several next-generation tokamak projects show that those kinds of equilibria could exist in such devices, which would also have enough additional heating power to promote an effective accessible ignition

Fuel policy of the United Kingdom in the 21-st century

International Nuclear Information System (INIS)

Smirnov, V.G.

1980-01-01

The main aspects of the United Kingdom fuel policy are analyzed. The possibility of using the new energy sources such as wind power, energy of waves, tide solar geothermal and thermonuclear energy is discussed. It is noted that in the large-scale power engineering for the purpose of fuel economy it is necessary to use schemes with combined production of heat and electric power. Construction of NPPs with thermal reactors having the total power of 40 GW by 2000 is projected as maximum program. Large commissioning of fast reactors is planned at the end of this century and at the beginning of next one. The exact date is determined by economic reasons, in particular, by the ratio of specific costs for thermal and fast reactors and relative cost of fuel cycle depending on the natural uranium cost. Favourable financial position of foreign partners and optimization of specifications of the NPP with a gas-cooled fast reactor (the use of helium or carbon dioxide is possible) make it possible to realize this reactor concept at the present stage approximately in two years. It is concluded that the development of methods for converting coal into liquid and gas fuels and transition to electric power production at NPPs are the main directions in fuel policy. In the future the use of wind and solar energy for district heating is the most favourable for the United Kingdom while the geothermal energy is the least perspective. In the far future the using the thermonuclear fusion is also perspective [ru

Status report on controlled thermonuclear fusion

International Nuclear Information System (INIS)

1990-06-01

The International Fusion Research Council (IFRC), an advisory body to the International Atomic Energy Agency, reports on the current status of fusion; this report updates its 1978 status report. This report contains a General Overview and Executive Summary, and reports on all current approaches to fusion throughout the world; a series of technical reports is to be published elsewhere. This report is timely in that it not only shows progress which has occurred over the past, but interfaces with possible future devices, in particular the International Thermonuclear Experimental Reactor (ITER), whose conceptual design phase is nearing completion. 5 refs, 6 figs

Rates of the main thermonuclear reactions

International Nuclear Information System (INIS)

Abramovich, S.N.; Guzhovskii, B.Ya.; Dunaeva, S.A.; Fomushkin, E.F.

1992-01-01

The data on the cross sections of main thermonuclear reactions have been estimated with an account of the latest experimental results in a form of S-factor spline presentation. Based on this estimation, the reates of these reactions in 0.0001-1 MeV temperature range in the supposition of Maxwell distribution of relative velocities have been computed. The Maxwell-Boltzmann averaged -factors were calculated according to the table values of the reaction rates. Then the -factors were approximated with the 3 order spline-function. The necessity of the account of electron shielding and intramolecular movement at low temperatures is discussed (orig.)

Threshold bubble chamber for measurement of knock-on DT neutron tails from magnetic and inertial confinement experiments

International Nuclear Information System (INIS)

Fisher, R.K.; Zaveryaev, V.S.; Trusillo, S.V.

1996-07-01

We propose a new open-quotes thresholdclose quotes bubble chamber detector for measurement of knock-on neutron tails. These energetic neutrons result from fusion reactions involving energetic fuel ions created by alpha knock-on collisions in tokamak and other magnetic confinement experiments, and by both alpha and neutron knock-on collisions in inertial confinement fusion (ICF) experiments. The energy spectrum of these neutrons will yield information on the alpha population and energy distribution in tokamaks, and on alpha target physics and ρR measurements in ICF experiments. The bubble chamber should only detect neutrons with energies above a selectable threshold energy controlled by the bubble chamber pressure. The bubble chamber threshold mechanism, detection efficiency, and proposed applications to the International Thermonuclear Experimental Reactor (ITER) and National Ignition Facility (NIF) experiments will be discussed

The TDF System for Thermonuclear Plasma Reaction Rates, Mean Energies and Two-Body Final State Particle Spectra

International Nuclear Information System (INIS)

Warshaw, S I

2001-01-01

The rate of thermonuclear reactions in hot plasmas as a function of local plasma temperature determines the way in which thermonuclear ignition and burning proceeds in the plasma. The conventional model approach to calculating these rates is to assume that the reacting nuclei in the plasma are in Maxwellian equilibrium at some well-defined plasma temperature, over which the statistical average of the reaction rate quantity σv is calculated, where σ is the cross-section for the reaction to proceed at the relative velocity v between the reacting particles. This approach is well-understood and is the basis for much nuclear fusion and astrophysical nuclear reaction rate data. The Thermonuclear Data File (TDF) system developed at the Lawrence Livermore National Laboratory (Warshaw 1991), which is the topic of this report, contains data on the Maxwellian-averaged thermonuclear reaction rates for various light nuclear reactions and the correspondingly Maxwellian-averaged energy spectra of the particles in the final state of those reactions as well. This spectral information closely models the output particle and energy distributions in a burning plasma, and therefore leads to more accurate computational treatments of thermonuclear burn, output particle energy deposition and diagnostics, in various contexts. In this report we review and derive the theoretical basis for calculating Maxwellian-averaged thermonuclear reaction rates, mean particle energies, and output particle spectral energy distributions for these reactions in the TDF system. The treatment of the kinematics is non-relativistic. The current version of the TDF system provides exit particle energy spectrum distributions for two-body final state reactions only. In a future report we will discuss and describe how output particle energy spectra for three- and four-body final states can be developed for the TDF system. We also include in this report a description of the algorithmic implementation of the TDF

D-T neutron skyshine experiments at JAERI/FNS

Energy Technology Data Exchange (ETDEWEB)

Nishitani, Takeo; Ochiai, Kentaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yoshida, Shigeo [Tokai Univ., Hiratsuka, Kanagawa (JP)] (and others)

2003-03-01

The D-T neutron skyshine experiments have been carried out at the Fusion Neutronics Source (FNS) of JAERI with the neutron yield of {approx}1.7x10{sup 11} n/s. The concrete thickness of the roof and the wall of a FNS target room are 1.15 and 2 m, respectively. The FNS skyshine port with a size of 0.9x0.9 m{sup 2} was open during the experimental period. The radiation dose rate outside the target room was measured as far as about 550 m away from the D-T target point with a spherical rem-counter. The highest neutron dose was about 0.5 {mu}Sv/hr at a distance of 30 m from the D-T target point and the dose rate was attenuated to 0.002 {mu}Sv/hr at a distance of 550 m. The measured neutron dose distribution was analyzed with Monte Carlo code MCNP-4B and a simple line source model. The MCNP calculation overestimates the neutron dose in the distance range larger than 250 m. The neutron spectra were evaluated with a {sup 3}He detector with different thickness of polyethylene neutron moderators. Secondary gamma-rays were measured with high purity Ge detectors and NaI scintillation detectors. (author)

Coupling and absorption of lower-hybrid waves in a thermonuclear plasma

International Nuclear Information System (INIS)

Puri, S.; Tutter, M.

1975-01-01

The three important aspects, namely 1) accessibility, 2) matching and 3) absorption of the lower-hybrid waves in a thermonuclear plasma are studied under idealized but physically pertinent conditions within the framework of linearized theory. (orig.) [de

D+D thermonuclear fusion reactions with polarized particles

International Nuclear Information System (INIS)

Kozma, P.

1986-01-01

Polarization measurements from the 2 H(d, n) 3 He and 2 H(d, p) 3 H thermonuclear reactions at deuteron energies below 1 MeV are anayzed. Results of analysis enable to discuss the existence of 4 He excited states in the vicinity of d+d threshold energy as well as to extrapolate total cross-sections σ tot (d+d) into the region of very low energies

Overview of International Thermonuclear Experimental Reactor (ITER) engineering design activities*

Science.gov (United States)

Shimomura, Y.

1994-05-01

The International Thermonuclear Experimental Reactor (ITER) [International Thermonuclear Experimental Reactor (ITER) (International Atomic Energy Agency, Vienna, 1988), ITER Documentation Series, No. 1] project is a multiphased project, presently proceeding under the auspices of the International Atomic Energy Agency according to the terms of a four-party agreement among the European Atomic Energy Community (EC), the Government of Japan (JA), the Government of the Russian Federation (RF), and the Government of the United States (US), ``the Parties.'' The ITER project is based on the tokamak, a Russian invention, and has since been brought to a high level of development in all major fusion programs in the world. The objective of ITER is to demonstrate the scientific and technological feasibility of fusion energy for peaceful purposes. The ITER design is being developed, with support from the Parties' four Home Teams and is in progress by the Joint Central Team. An overview of ITER Design activities is presented.

Cross sections and thermonuclear reaction rates of proton-induced reactions on 37Cl

International Nuclear Information System (INIS)

Weber, R.O.; Tingwell, C.I.W.; Mitchell, L.W.; Sevior, M.E.; Sargood, D.G.

1984-01-01

The yields of γ-rays from the reactions of 37 Cl(p,γ) 38 Ar and 37 Cl(p,αγ) 34 S have been measured as a of bombarding energy over the ranges 0.65 - 2.15 MeV and 1.25 -2.15 MeV respectively, and the yield of neutrons from 37 Cl(p,n) 37 Ar from threshold to 2.50 MeV. The results are compared with global statistical-model calculations and thermonuclear reaction rates are calculated for the temperature range 5 x 10 8 - 10 10 K. The significance of these thermonuclear reaction rates for stellar nucleosynthesis calculations is discussed

Theses of the reports of the XXXI Zvenigorod conference on the plasma physics and controlled thermonuclear synthesis

International Nuclear Information System (INIS)

Kovrizhnykh, L.M.; Ivanov, V.A.; Nagaeva, M.L.; Aleksandrov, A.F.; Vorob'ev, V.S.; Ivanenkov, G.V.; Meshcheryakov, A.I.

2004-01-01

Theses of the reports of the 31th Zvenigorod Conference on the physics and controlled thermonuclear synthesis, presented by Russian and foreign scientists, are published. The total number of reports is 258, namely, summarizing ones 16, magnetic confinement of high temperature plasma - 98, inertial thermonuclear synthesis - 44, physical processes in low temperature plasma - 58, physical bases of plasma and beam technologies - 42 [ru

MUON DETECTOR BARREL DRIFT TUBES (DT)

CERN Multimedia

Fabrizio Gasparini

The DT system is made of 250 chambers, installed in the five wheels of the CMS Iron Yoke. Each wheel is subdivided in 10 sectors of four chambers each. Two sectors per wheel, the top and bottom ones, are equipped with 5 chambers, the large outer MB4s being split in two. The electronics for local, i.e. chamber, readout and generation of trigger primitives sits on Minicrates installed on each chamber (on-detector electronics). The data from each chamber are collected and synchronized by the off-detector electronics, sitting on the Wheel towers and organized per sector. HV and LV are organized per sector and per quarter (3 sectors) of each wheel respectively, DAQ and DCS have one branch per wheel. At the end of the February CMS Week the central wheel was fully operational and the two positive wheels, YB+1 and +2, fully commissioned. They were successfully moved over the vacuum tank and closed against YB0. The negative wheels were still open, with DT commissioning and final LV and DCS cabling being completed ...

Enhancement of D-T reaction rate due to D-T contact

International Nuclear Information System (INIS)

Hitoki, Shigehisa; Ogasawara, Masatada; Aono, Osamu.

1979-09-01

The reaction rate that is appropriate for magnetized nonuniform plasma is numerically calculated to investigate the enhancement of the D-T reaction rate. Spatial separation of the guiding center distributions of D and T enhances the reaction rate. Cases of several guiding center configurations are investigated. The largest enhancement is obtained, when both guiding center distributions are delta-functions which are separated by a length that corresponds to the Gamow peak energy. As compared with the case of no separation of D and T, the maximum enhancing factors obtained are 2.3 for total reaction rate and 1.6 for local reaction rate. Cases of the guiding center distributions with finite widths are also investigated. (author)

Oak Ridge TNS program: study of fueling techniques in support of TNS development

International Nuclear Information System (INIS)

Simpson, W.

1979-12-01

The objective of this study was to survey fueling techniques and determine which approaches were compatible with the TNS requirements. Specifically, the following tasks were undertaken: survey of existing fueling concepts for use in TNS, determination of available physical properties for D-T fuel pellets, performance of preliminary load analysis of selected pellet acceleration machines, preparation of conceptual designs, and recommendations for follow-up work

Oscillations During Thermonuclear X-ray Bursts: A New Probe of Neutron Stars

Science.gov (United States)

Strohmayer, Tod E.; White, Nicholas E. (Technical Monitor)

2002-01-01

Observations of thermonuclear (also called Type 1) X-ray bursts from neutron stars in low mass X-ray binaries (LMXB) with the Rossi X-ray Timing Explorer (RXTE) have revealed large amplitude, high coherence X-ray brightness oscillations with frequencies in the 300 - 600 Hz range. Substantial spectral and timing evidence point to rotational modulation of the X-ray burst flux as the cause of these oscillations, and it is likely that they reveal the spin frequencies of neutron stars in LMXB from which they are detected. Here we review the status of our knowledge of these oscillations and describe how they can be used to constrain the masses and radii of neutron stars as well as the physics of thermonuclear burning on accreting neutron stars.

Bi-cone system of concentric, explosion-induced D-T compression

International Nuclear Information System (INIS)

Kaliski, S.

1978-01-01

The concept and the assessment is given of the neutron yield for the bi-cone cumulative system with the aid whereof a spherical deuterized-polyethylene shell has been imploded into D-T (D) gas. The assessment of neutron yield within the limits of 10 10 - 5 x 10 10 has been obtained for D-T gas as well as 2 x 10 8 - 10 9 for D-gas. The assessments are approximate with an accuracy of an order of magnitude. (author)

Estimated D2--DT--T2 phase diagram in the three-phase region

International Nuclear Information System (INIS)

Souers, P.C.; Hickman, R.G.; Tsugawa, R.T.

1976-01-01

A composite of experimental eH 2 -D 2 phase-diagram data at the three-phase line is assembled from the literature. The phase diagram is a smooth cigar shape without a eutectic point, indicating complete miscibility of liquid and solid phases. Additional data is used to estimate the D 2 -T 2 , D 2 DT, and DT-T 2 binary phase diagrams. These are assembled into the ternary D 2 -DT-T 2 phase diagram. A surface representing the chemical equilibrium of the three species is added to the phase diagram. At chemical equilibrium, it is estimated that 50-50 liquid D-T at 19.7 0 K is in equilibrium with 42 mole percent T vapor and 54 percent T solid. Infrared spectroscopy is suggested as a means of component analysis of liquid and solid mixtures

Modulation of radioresponse of DT-diaphorase by Curcumin

International Nuclear Information System (INIS)

Chandra, D.; Choudhary, D.; Kale, R.K.

1998-01-01

In the present work, Curcumin (diferuloyl methane), a phytochemical present in the rhizome of Curcuma longa Linn. has been examined for its radioprotective property using the DT-diaphorase (DTD) system

Plasma and controlled thermonuclear reaction

International Nuclear Information System (INIS)

Kapitsa, P.

1980-01-01

The principle and prospects are given of three methods of achieving controlled thermonuclear reaction. The original and so far most promising TOKAMAK method is presented invented in the USSR. Another method is the heating of a sphere about 1 mm in diameter from a mixture of deuterium and tritium by focused laser light from all sides. The third method consists in continuous plasma heating. A rope-like plasma discharge at a temperature of more than a million K results in the gas from microwave oscillations. The discharge is placed in a magnetic field and the ion temperature is increased by magneto-acoustic waves. A reactor is proposed operating on this principle and problems are pointed out which will have to be resolved. (M.S.)

Plasma and controlled thermonuclear reaction

Energy Technology Data Exchange (ETDEWEB)

Kapitsa, P

1980-06-01

The principle and prospects are given of three methods of achieving controlled thermonuclear reaction. The original and so far most promising TOKAMAK method is presented invented in the USSR. Another method is the heating of a sphere about 1 mm in diameter from a mixture of deuterium and tritium by focused laser light from all sides. The third method consists in continuous plasma heating. A rope-like plasma discharge at a temperature of more than a million K results in the gas from microwave oscillations. The discharge is placed in a magnetic field and the ion temperature is increased by magneto-acoustic waves. A reactor is proposed operating on this principle and problems are pointed out which will have to be resolved.

DT Local Trigger performance in 2015

CERN Document Server

CMS Collaboration

2015-01-01

The Local Trigger system of the CMS Drift Tube chambers (DT) was checked applying similar methods as in the LHC Run 1 (2012). The main variables shown in this note are the trigger efficiency, the trigger quality and the fraction of trigger ghosts. The performance was found to be comparable or better than in Run 1.

Synthetic report 2012. Research programme on controlled thermonuclear fusion

International Nuclear Information System (INIS)

Vaucher, C.; Tran, M. Q.; Villard, L.; Marot, L.

2013-01-01

Since 1961, Switzerland participates in the research on thermonuclear fusion thanks to the creation of the Research Centre in Plasma Physics. In 1979 it entered into partnership with the European programme on fusion through its adhesion to EURATOM. The thermonuclear fusion is an interesting energy source because the basic fuel is practically inexhaustible and its use does not release any significant CO 2 quantity and very little radioactive residues. But its working up faces enormous physical and technological difficulties. The International Thermonuclear Reactor (ITER), presently in construction, has to demonstrate the technological feasibility of the controlled fusion. Il will be followed by DEMO, foreseen for 2040-2050, which must guarantee the economical rentability. At CRPP the research projects are partitioned onto several sites: at the Swiss Federal Institute of Technology (EPFL) in Lausanne, they concern the physics of the magnetic confinement with the Variable Geometry Tokamak (TCV), the development of theoretical models and the numerical simulation, the plasma heating and the generation of hyper frequency waves; the Paul Scherrer Institute (PSI) studies the superconductivity and the materials; the interactions between the plasma and the Tokamak walls are studied at the Basel University for the structures of ITER. Thanks to its large flexibility, TCV allows the creation and the control of plasmas of very different forms. The injection system of millimetric waves allows orienting the injected power according to specific profiles. By using the asymmetry of the flow in the toroidal sense, the plasma rotation could be measured with a much better accuracy than before. In TCV, by playing on the form of the plasma, it was possible to strongly reduce the energy quantity which is expelled by the Edge Localized Modes (ELM) onto the wall of the vacuum chamber. The ‘snowflake’ configuration created in TCV allows distributing the ELM energy onto several impact

Investigating the foil-generated deuteron beam interaction with a DT target in degenerate and classical plasma

Science.gov (United States)

Mehrangiz, M.; Ghasemizad, A.

2017-06-01

Deuteron fast ignition of a conically guided pre-compressed DT fuel is investigated. For this purpose, the acceleration of the deuterated thin foil by the intense laser beam is evaluated. The acceleration values and the number of foil-generated deuterons are calculated in terms of the laser pulse duration. Using the created deuterons as the fast ignitors, we investigate the fast ignition scheme by comparing fully degenerate, partial degenerate and classical types of DT plasma. The total energy gain of deuterons "beam fusion" is calculated to show the efficiency of beam reactions in increasing fusion rate. Besides, the stopping time and stopping range of incident deuterons are evaluated. Our numerical results indicate that degeneracy increases the beam-target collisions. Thus, it prepares the ignition situation sooner than the classical plasma. Moreover, the number of generated deuterons and their acceleration depend on the foil thickness and laser parameters. We show that when a 4ps laser with intensity of 10^{19} W/cm^2 focused onto a 20μm foil, 35× 10^{15} deuterons are generated. Moreover, under our analysis, in order to have a practicable fast ignition, 18% of the laser energy is necessary to convert into a deuteron driver.

Foil deposition alpha collector probe for TFTR's D-T phase

International Nuclear Information System (INIS)

Hermann, H.W.; Darrow, D.S.; Timberlake, J.; Zweben, S.J.; Chong, G.P.; Pitcher, C.S.; Macaulay-Newcombe, R.G.

1995-03-01

A new foil deposition alpha collector sample probe has been developed for TFTR's D-T phase. D-T fusion produced alpha particles escaping from the plasma are implanted in nickel foils located in a series of collimating ports on the detector. The nickel foils are removed from the tokamak after exposure to one or more plasma discharges and analyzed for helium content. This detector is intended to provide improved alpha particle energy resolution and pitch angle coverage over existing lost alpha detectors, and to provide an absolutely calibrated cross-check with these detectors. The ability to resolve between separate energy components of alpha particle loss is estimated to be ∼ 20%. A full 360 degree of pitch angle coverage is provided for by 8 channels having an acceptance range of ∼ 53 degree per channel. These detectors will be useful in characterizing classical and anomalous alpha losses and any collective alpha instabilities that may be excited during the D-T campaign of TFTR

Estimated refractive index and solid density of DT, with application to hollow-microsphere laser targets

International Nuclear Information System (INIS)

Briggs, C.K.; Tsugawa, R.T.; Hendricks, C.D.; Souers, P.C.

1975-01-01

The literature values for the 0.55-μm refractive index N of liquid and gaseous H 2 and D 2 are combined to yield the equation (N - 1) = [(3.15 +- 0.12) x 10 -6 ]rho, where rho is the density in moles per cubic meter. This equation can be extrapolated to 300 0 K for use on DT in solid, liquid, and gas phases. The equation is based on a review of solid-hydrogen densities measured in bulk and also by diffraction methods. By extrapolation, the estimated densities and 0.55-μm refractive indices for DT are given. Radiation-induced point defects could possibly cause optical absorption and a resulting increased refractive index in solid DT and T 2 . The effect of the DT refractive index in measuring glass and cryogenic DT laser targets is also described

What is the Plasma Focus Thermonuclear Pulsors Technology?

International Nuclear Information System (INIS)

Ramos, R.; Gonzalez, J.; Moreno, C.; Clausse, A.

2003-01-01

In this paper we describe a type of neutron generators, called Plasma Focus, which is suitable to several applications, where traditional generators are non-applicable.The main characteristics are its transportability and to be non-contaminating, which would allow in-situ tests.The Plasma Focus, produces neutron pulses by thermonuclear fusion reactions, satisfy these requirements and it is comparatively non expensive.This last feature would assure competitivity in the neutron sources market

Reaction-in-flight neutrons as a signature for shell mixing in National Ignition Facility capsules

International Nuclear Information System (INIS)

Hayes, A. C.; Bradley, P. A.; Grim, G. P.; Jungman, Gerard; Wilhelmy, J. B.

2010-01-01

Analytic calculations and results from computational simulations are presented that suggest that reaction-in-flight (RIF) neutrons can be used to diagnose mixing of the ablator shell material into the fuel in deuterium-tritium (DT) capsules designed for the National Ignition Facility (NIF) [J. A. Paisner, J. D. Boyes, S. A. Kumpan, W. H. Lowdermilk, and M. S. Sorem, Laser Focus World 30, 75 (1994)]. Such mixing processes in NIF capsules are of fundamental physical interest and can have important effects on capsule performance, quenching the total thermonuclear yield. The sensitivity of RIF neutrons to hydrodynamical mixing arises through the dependence of RIF production on charged-particle stopping lengths in the mixture of DT fuel and ablator material. Since the stopping power in the plasma is a sensitive function of the electron temperature and density, it is also sensitive to mix. RIF production scales approximately inversely with the degree of mixing taking place, and the ratio of RIF to down-scattered neutrons provides a measure of the mix fraction and/or the mixing length. For sufficiently high-yield capsules, where spatially resolved RIF images may be possible, neutron imaging could be used to map RIF images into detailed mix images.

Alternate fusion fuels workshop

International Nuclear Information System (INIS)

1981-06-01

The workshop was organized to focus on a specific confinement scheme: the tokamak. The workshop was divided into two parts: systems and physics. The topics discussed in the systems session were narrowly focused on systems and engineering considerations in the tokamak geometry. The workshop participants reviewed the status of system studies, trade-offs between d-t and d-d based reactors and engineering problems associated with the design of a high-temperature, high-field reactor utilizing advanced fuels. In the physics session issues were discussed dealing with high-beta stability, synchrotron losses and transport in alternate fuel systems. The agenda for the workshop is attached

Thermonuclear 36Cl pulse in natural water

International Nuclear Information System (INIS)

Bentley, H.W.; Davis, S.N.; Gifford, S.; Phillips, E.M.; Elmore, D.; Tubbs, L.E.; Gove, H.E.

1982-01-01

The enhanced concentration of 3 6Cl, produced by neutron activation of seawater and released into the environment during atmospheric thermonuclear tests in the 1950s, has been used as a tracer in natural water systems. The results of numerical modelling and analyses of water samples are presented which indicate that in the mid-latitudes the fallout peak was 3 orders of magnitude above the natural background, and that the period of enhanced 36 Cl fallout was 1953 to about 1964. The advantages of 36Cl as an environmental tracer are discussed. (U.K.)

Zone-plate coded imaging of thermonuclear burn

International Nuclear Information System (INIS)

Ceglio, N.M.

1978-01-01

The first high-resolution, direct images of the region of thermonuclear burn in laser fusion experiments have been produced using a novel, two-step imaging technique called zone-plate coded imaging. This technique is extremely versatile and well suited for the microscopy of laser fusion targets. It has a tomographic capability, which provides three-dimensional images of the source distribution. It is equally useful for imaging x-ray and particle emissions. Since this technique is much more sensitive than competing imaging techniques, it permits us to investigate low-intensity sources

On the absolute calibration of a DT fusion neutron yield diagnostic

Directory of Open Access Journals (Sweden)

Ruiz C.L.

2013-11-01

Full Text Available Recent advances in Inertial Confinement Fusion (ICF experiments at Lawrence Livermore National Laboratory's National Ignition Facility (NIF have underscored the need for accurate total yield measurements of DT neutrons because yield measurements provide a measure of the predicted performance of the experiments. Future gas-puff DT experiments at Sandia National Laboratory's Z facility will also require similar measurements. For ICF DT experiments, the standard technique for measuring the neutron (14.1 MeV yield, counts the activity (counts/minute induced in irradiated copper samples. This activity occurs by the 63Cu(n,2n62Cu reaction where 62Cu decays by positrons (β+ with a half-life of 9.67 minutes. The calibrations discussed here employ the associated-particle method (APM, where the α (4He particles from the T(d,n4He reaction are measured to infer neutron fluxes on a copper sample. The flux induces 62Cu activity, measured in a coincidence counting system. The method leads to a relationship between a DT neutron yield and copper activity known as the F-factor. The goal in future experiments is to apply this calibration to measure the yield at NIF with a combined uncertainty approaching 5%.

FROM THE HISTORY OF PHYSICS: The extraordinarily beautiful physical principle of thermonuclear charge design (on the occasion of the 50th anniversary of the test of RDS-37 — the first Soviet two-stage thermonuclear charge)

Science.gov (United States)

Goncharov, German A.

2005-11-01

On 22 November 1955, the Semipalatinsk test site saw the test of the first domestic two-stage thermonuclear RDS-37 charge. The charge operation was based on the principle of radiation implosion. The kernel of the principle consists in the radiation generated in a primary A-bomb explosion and confined by the radiation-opaque casing propagating throughout the interior casing volume and flowing around the secondary thermonuclear unit. The secondary unit experiences a strong compression under the irradiation, with a resulting nuclear and thermonuclear explosion. The RDS-37 explosion was the strongest of all those ever realized at the Semipalatinsk test site. It produced an indelible impression on the participants in the test. This document-based paper describes the genesis of the ideas underlying the RDS-37 design and reflects the critical moments in its development. The advent of RDS-37 was an outstanding accomplishment of the scientists and engineers of our country.

Threshold bubble chamber for measurement of knock-on DT neutron tails from magnetic and inertial confinement experiments

International Nuclear Information System (INIS)

Fisher, R.K.; Zaveryaev, V.S.; Trusillo, S.V.

1997-01-01

We propose a new open-quotes thresholdclose quotes bubble chamber detector for measurement of knock-on neutron tails. These energetic neutrons result from fusion reactions involving energetic fuel ions created by alpha knock-on collisions in tokamak and other magnetic confinement experiments, and by both alpha and neutron knock-on collisions in inertial confinement fusion (ICF) experiments. The energy spectrum of these neutrons will yield information on the alpha population and energy distribution in tokamaks, and on alpha target physics and ρR measurements in ICF experiments. The bubble chamber should only detect neutrons with energies above a selectable threshold energy controlled by the bubble chamber pressure. The bubble chamber threshold mechanism, detection efficiency, and proposed applications to the International Thermonuclear Experimental Reactor and National Ignition Facility experiments will be discussed. copyright 1997 American Institute of Physics

Physics of fusion-fuel cycles

International Nuclear Information System (INIS)

McNally, J.R. Jr.

1981-01-01

The evaluation of nuclear fusion fuels for a magnetic fusion economy must take into account the various technological impacts of the various fusion fuel cycles as well as the relative reactivity and the required β's and temperatures necessary for economic steady-state burns. This paper will review some of the physics of the various fusion fuel cycles (D-T, catalyzed D-D, D- 3 He, D- 6 Li, and the exotic fuels: 3 He 3 He and the proton-based fuels such as P- 6 Li, P- 9 Be, and P- 11 B) including such items as: (1) tritium inventory, burnup, and recycle, (2) neutrons, (3) condensable fuels and ashes, (4) direct electrical recovery prospects, (5) fissile breeding, etc. The advantages as well as the disadvantages of the different fusion fuel cycles will be discussed. The optimum fuel cycle from an overall standpoint of viability and potential technological considerations appears to be catalyzed D-D, which could also support smaller relatively clean, lean-D, rich- 3 He satellite reactors as well as fission reactors

Trapping of pellet cloud radiation in thermonuclear plasmas

International Nuclear Information System (INIS)

Sergeev, V.Yu.; Miroshinikov, I.V.; Sudo, Shigeru; Namba, C.; Lisitsa, V.S.

2001-01-01

The experimental and theoretical data on radiation trapping in clouds of pellets injected into thermonuclear plasmas are presented. The theoretical modeling is performed in terms of equivalent Stark spectral line widths under condition of LTE (Sakha-Boltzman) in pellet cloud plasmas. It is shown that a domain of blackbody radiation could exist in hydrogen pellet clouds resulting in ''pellet disappearance'' effect which is absent in a case of impurity pellet clouds. Reasons for this difference are discussed. (author)

International Thermonuclear Experimental Reactor

International Nuclear Information System (INIS)

Blevins, J.D.; Stasko, R.R.

1989-09-01

An international design team comprised of members from Canada, Europe, Japan, the Soviet Union, and the United States of America, are designing an experimental fusion test reactor. The engineering and testing objectives of this International Thermonuclear Experimental Reactor (ITER) are to validate the design and to demonstrate controlled ignition, extended burn of a deuterium and tritium plasma, and achieve steady state using technology expected to be available by 1990. The concept maximizes flexibility while allowing for a variety of plasma configurations and operating scenarios. During physics phase operation, the machine produces a 22 MA plasma current. In the technology phase, the machine can be reconfigured with a thicker shield and a breeding blanket to operate with an 18 MA plasma current at a major radius of 5.5 meters. Canada's involvement in the areas of safety, facility design, reactor configuration and maintenance builds on our internationally recognized design and operational expertise in developing tritium processes and CANDU related technologies

Laser fusion experiments, facilities and diagnostics at Lawrence Livermore Laboratory

International Nuclear Information System (INIS)

Ahlstrom, H.G.

1980-02-01

The progress of the LLL Laser Fusion Program to achieve high gain thermonuclear micro-explosions is discussed. Many experiments have been successfully performed and diagnosed using the large complex, 10-beam, 30 TW Shiva laser system. A 400 kJ design of the 20-beam Nova laser has been completed. The construction of the first phase of this facility has begun. New diagnostic instruments are described which provide one with new and improved resolution, information on laser absorption and scattering, thermal energy flow, suprathermal electrons and their effects, and final fuel conditions. Measurements were made on the absorption and Brillouin scattering for target irradiations at both 1.064 μm and 532 nm. These measurements confirm the expected increased absorption and reduced scattering at the shorter wavelength. Implosion experiments have been performed which have produced final fuel densities over the range of 10x to 100x liquid DT density

Design and cost evaluation of generic magnetic fusion reactor using the D-D fuel cycle

International Nuclear Information System (INIS)

Shannon, T.E.

1988-01-01

A fusion reactor systems code has been developed to evaluate the economic potential of power generation from a toroidal magnetic fusion reactor using deuterium-deuterium (D-D) fuel. A method similar to that developed by J. Sheffield, of the Oak Ridge National Laboratory, for deuterium-tritium (D-T) fuel was used to model the generic aspects of magnetic fusion reactors. The results of the systems study and cost evaluation show that the cost of electricity produced by a D-D reactor is two times higher than that produced by an equivalent D-T reactor design. The significant finding of the study is that the cost ratio between the D-D and D-T systems can potentially be reduced to 1.5 by improved engineering design and even lower by better physics performance. The absolute costs for both systems at this level are close to the costs for nuclear fission and fossil fuel plants. A design for a magnet reinforced with advanced composite materials is presented as an example of an engineering improvement that could reduce the cost of electricity produced by both reactors. However, since the magnets in the D-D reactor are much larger than in the K-T reactor, the cost ratio of the two systems is significantly reduced

Polarized advanced fuel reactors

International Nuclear Information System (INIS)

Kulsrud, R.M.

1987-07-01

The d- 3 He reaction has the same spin dependence as the d-t reaction. It produces no neutrons, so that if the d-d reactivity could be reduced, it would lead to a neutron-lean reactor. The current understanding of the possible suppression of the d-d reactivity by spin polarization is discussed. The question as to whether a suppression is possible is still unresolved. Other advanced fuel reactions are briefly discussed. 11 refs

Flaw detection device for plasma facing wall in thermonuclear device

International Nuclear Information System (INIS)

Doi, Akira.

1996-01-01

The present invention concerns plasma facing walls of a thermonuclear device and provides a device for detecting a thickness of amour tiles accurately and efficiently with no manual operation. Namely, the position of the plasma facing surface of the amour tile is measured using a structure to which the amour tiles are to be disposed as a reference. Also in a case of disposing new armor tiles, the position of the plasma facing surface of the armor tiles is measured to thereby measure the wearing amount of the amour tiles based on the difference between the reference and the measured value. If a measuring means capable of measuring a plurality of amour tiles at once is used efficiency of the measurement and the detection can be enhanced. Several ten thousands of amour tiles are disposed to the plasma facing wall in a large scaled thermonuclear device, and a plenty of time was required for the detection. However, the present invention can improve the accuracy for the measurement and detection and provide time and labors-saving. (I.S.)

Profile and predictors of global distress: can the DT guide nursing practice in prostate cancer?

Science.gov (United States)

Lotfi-Jam, Kerryann; Gough, Karla; Schofield, Penelope; Aranda, Sanchia

2014-02-01

This study examines the ability of the distress thermometer to accurately identify patients with higher symptoms, unmet needs and psychological morbidity. Baseline data collected as part of a randomized controlled trial evaluating a nurse-led supportive care intervention for men with prostate cancer commencing radiotherapy at a specialist cancer hospital in Melbourne, Australia. Measures assessed global distress (DT), anxious and depressive symptomatology (HADS), prostate-cancer specific quality of life (EPIC-26), unmet supportive care needs (SCNS-SF34R) and cancer treatment-related concerns (CATS). Following descriptive and correlational analysis, hierarchical multiple regression was employed to examine the contribution of variable sets to explaining variance in DT scores. Less than 20% of men reported DT scores of 4 or higher, indicating overall low distress. The DT accurately identified almost all men reporting HADS score indicative of anxious or depressive symptomatology, suggesting it accurately identifies psychological morbidity. Importantly, the DT identified a further group of distressed men, not identified by HADS, whose distress related to unmet needs and prostate cancer-specific issues, indicating the DT is superior in identifying other forms of distress. While the hierarchical multiple regression confirmed anxious and depressive symptomatology as the best predictor of distress score, many other scales are also good predictors of DT scores, supporting the argument that distress is multi-determined. Nurses can be confident that the DT accurately identifies patients with psychological morbidity and importantly identifies other patients with distress who may require intervention. A distress score of 4 or higher identified participants with higher physical symptomatology, higher unmet needs, more concerns about treatment and poorer quality of life. The low prevalence of distress reaching cut off scores suggests nurses would not be overwhelmed by the outcomes

Design of analytical instrumentation with D-T sealed neutron generators

International Nuclear Information System (INIS)

Qiao Yahua; Wu Jizong; Zheng Weiming; Liu Quanwei; Zhang Min

2008-01-01

Analytical instrumentation with D-T sealed neutron generators source activation, The 14 MeV D-T sealed neutron tube with 10 9 n · s -1 neutron yield is used as generator source. The optimal structure of moderator and shield was achieved by MC computing.The instrumentation's configuration is showed. The instrumentation is made up of the SMY-DT50.8-2.1 sealed neutron tube and the high-voltage power supply system, which center is the sealed neutron generators. 6 cm Pb and 20 cm polythene is chosen as moderator, Pb, polythene and 10 cm boron-PE was chosen as shield .The sample box is far the source from 9 cm, the measurement system were made up of HPGe detector and the sample transforming system. After moderator and shield, the thermal neutron fluence rate at the point of sample is 0.93 × 10 6 n · s -1 cm -2 , which is accorded with design demand, and the laboratory and surroundings reaches the safety standard of the dose levels. (authors)

Implications of the recent D-T μCF experiments at RIKEN-RAL and near-future directions

International Nuclear Information System (INIS)

Nagamine, K.; Matsuzaki, T.; Ishida, K.; Nakamura, S.N.; Kawamura, N.

1999-01-01

The paper describes physics implications obtained through the recent experimental results on D-T μCF at RIKEN-RAL. Smaller sticking and larger cycling rates in solid/liquid D-T mixture than the theoretical predictions were observed, suggesting needs of further theoretical understandings. Some possible future directions in D-T μCF experiments are also described

Dynamic recrystallization mechanisms and their transition in the Daling Thrust (DT) zone, Darjeeling-Sikkim Himalaya

Science.gov (United States)

Ghosh, Subhajit; Bose, Santanu; Mandal, Nibir; Dasgupta, Sujoy

2016-04-01

The Daling Thrust (DT) delineates a zone of intense shear localization in the Lesser Himalayan Sequence (LHS) of the Darjeeling-Sikkim Himalaya. From microstructural studies of deformed quartzite samples, we show a transition in the dynamic recrystallization mechanism with increasing distance from the DT, dominated by grain boundary bulging (BLG) recrystallization closest to the DT, and progressively replaced by sub-grain rotation (SGR) recrystallization away from the thrust. The transition is marked by a characteristic variation in the fractal dimension (D) of grain boundaries, estimated from the area-perimeter method. For the BLG regime, D ≈ 1.046, which decreases significantly to a value as low as 1.025 for the SGR regime. Using the available thermal data for BLG and SGR recrystallization, we infer increasing deformation temperatures away from the DT in the hanging wall. Based on the quartz piezometer our estimates reveal strong variations in the flow stress (59.00 MPa to 16.00 MPa) over a distance of 1.2 km from the DT. Deformation mechanism maps constructed for different temperatures indicate that the strain rates (10- 12 S- 1 to 10- 14 S- 1) comply with the geologically possible range. Finally, we present a mechanical model to provide a possible explanation for the cause of stress intensification along the DT.

MILLIHERTZ QUASI-PERIODIC OSCILLATIONS AND THERMONUCLEAR BURSTS FROM TERZAN 5: A SHOWCASE OF BURNING REGIMES

Energy Technology Data Exchange (ETDEWEB)

Linares, M.; Chakrabarty, D. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139 (United States); Altamirano, D. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam and Center for High-Energy Astrophysics, P.O. BOX 94249, 1090 GE Amsterdam (Netherlands); Cumming, A. [Department of Physics, McGill University, 3600 Rue University, Montreal, QC H3A 2T8 (Canada); Keek, L. [School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

2012-04-01

We present a comprehensive study of the thermonuclear bursts and millihertz quasi-periodic oscillations (mHz QPOs) from the neutron star (NS) transient and 11 Hz X-ray pulsar IGR J17480-2446, located in the globular cluster Terzan 5. The increase in burst rate that we found during its 2010 outburst, when persistent luminosity rose from 0.1 to 0.5 times the Eddington limit, is in qualitative agreement with thermonuclear burning theory yet contrary to all previous observations of thermonuclear bursts. Thermonuclear bursts gradually evolved into a mHz QPO when the accretion rate increased, and vice versa. The mHz QPOs from IGR J17480-2446 resemble those previously observed in other accreting NSs, yet they feature lower frequencies (by a factor {approx}3) and occur when the persistent luminosity is higher (by a factor 4-25). We find four distinct bursting regimes and a steep (close to inverse cubic) decrease of the burst recurrence time with increasing persistent luminosity. We compare these findings to nuclear burning models and find evidence for a transition between the pure helium and mixed hydrogen/helium ignition regimes when the persistent luminosity was about 0.3 times the Eddington limit. We also point out important discrepancies between the observed bursts and theory, which predicts brighter and less frequent bursts, and suggest that an additional source of heat in the NS envelope is required to reconcile the observed and expected burst properties. We discuss the impact of NS magnetic field and spin on the expected nuclear burning regimes, in the context of this particular pulsar.

Measurement of radiation skyshine with D-T neutron source

Energy Technology Data Exchange (ETDEWEB)

Yoshida, S.; Nishitani, T. E-mail: nisitani@naka.jaeri.go.jp; Ochiai, K.; Kaneko, J.; Hori, J.; Sato, S.; Yamauchi, M.; Tanaka, R.; Nakao, M.; Wada, M.; Wakisaka, M.; Murata, I.; Kutsukake, C.; Tanaka, S.; Sawamura, T.; Takahashi, A

2003-09-01

The D-T neutron skyshine experiments have been carried out at the Fusion Neutronics Source (FNS) of JAERI with the neutron yield of {approx}1.7x10{sup 11} n/s. The concrete thickness of the roof and the wall of a FNS target room are 1.15 and 2 m, respectively. The FNS skyshine port with a size of 0.9x0.9 m{sup 2} was open during the experimental period. The radiation dose rate outside the target room was measured a maximum distance of 550 m from the D-T target point with a spherical rem-counter. Secondary gamma-rays were measured with high purity Ge detectors and NaI scintillation counters. The highest neutron dose was about 9x10{sup -22} Sv/(source neutron) at a distance of 30 m from the D-T target point and the dose rate was attenuated to 4x10{sup -24} Sv/(source neutron) at a distance of 550 m. The measured neutron dose distribution was analyzed with Monte Carlo code MCNP-4B and a simple line source model. The MCNP calculation overestimates the neutron dose in the distance range larger than 230 m. The line source model agrees well with the experimental results within the distance of 350 m.

D₂ and DT Liquid-Layer Target Shots on NIF

Energy Technology Data Exchange (ETDEWEB)

Walters, Curtis [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alger, Ethan [General Atomics, San Diego, CA (United States); Bhandarkar, Suhas [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Boehm, Kurt [General Atomics, San Diego, CA (United States); Braun, Tom [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Espinosaloza, Francisco [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haid, Benjamin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Heredia, Ricardo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kline, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kozioziemski, Bernard [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kroll, Jeremy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Malone, Daniel [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nikroo, Abbas [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Opsahl, Patrick [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sater, James [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zylstra, Alex [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-22

Experiments at the National Ignition Facility (NIF) using targets containing a Deuterium-Tritium (DT) fuel layer have, until recently, required that a high-quality layer of solid deuterium-tritium (herein referred to as an "ice-layer") be formed in the capsule. The development of a process to line the inner surface of a target capsule with a foam layer of a thickness that is typical of icelayers has resulted in the ability to field targets with liquid layers wetting the foam. Successful fielding of liquid-layer targets on NIF required not only a foam lined capsule, but also changes to the capsule filling process and the manner with which the inventory is maintained in the capsule. Additionally, changes to target heater power and the temperature drops across target components were required in order to achieve the desired range of shot temperatures. These changes, and the target's performance during four target shots on NIF will be discussed.

A method for carrying out radiolysis and chemical reactions by means of the radiations resulting from a thermonuclear reaction

International Nuclear Information System (INIS)

Gomberg, H.J.

1974-01-01

The invention relates to the use of the radiations resulting from thermonuclear reactions. It deals with a method comprising a combination of thermo-chemical and radiolytic reactions for treating a molecule having a high absorption rate, by the radiations of a thermonuclear reaction. This is applicable to the dissociation of water into oxygen and hydrogen [fr

Effect of excited states on thermonuclear reaction rates

International Nuclear Information System (INIS)

Sargood, D.G.

1983-01-01

Values of the ratio of the thermonuclear reaction rate of a reaction, with target nuclei in a thermal distribution of energy states, to the reaction rate with all target nuclei in their ground states are tabulated for neutron, proton and α-particle induced reactions on the naturally occurring nuclei from 20 Ne to 70 Zn, at temperatures of 1, 2, 3.5 and 5x10 9 K. The ratios are determined from reaction rates based on statistical model cross sections

Controlled thermonuclear reactions and Tora Supra program

International Nuclear Information System (INIS)

1988-01-01

The research programs for the nuclear energy production by means of thermonuclear fusion are shown. TORA SUPRA, Joint European Torus, Next European Torus and those developed at the Atomic Energy Center are described. The controlled fusion necessary conditions, the energy and confinement balance, and the research of a better tokamak configuration are discussed. A description of TORA SUPRA, the ways of achieving the project and the expected delays are shown. The Controlled Fusion Research Department functions, concerning these programs, are described. The importance of international cooperation and the perspectives about the use of controlled fusion are underlined [fr

An approach for evaluating the integrity of fuel applied in Innovative Nuclear Energy Systems

International Nuclear Information System (INIS)

Nakae, Nobuo; Ozawa, Takayuki; Ohta, Hirokazu; Ogata, Takanari; Sekimoto, Hiroshi

2014-01-01

One of the important issues in the study of Innovative Nuclear Energy Systems is evaluating the integrity of fuel applied in Innovative Nuclear Energy Systems. An approach for evaluating the integrity of the fuel is discussed here based on the procedure currently used in the integrity evaluation of fast reactor fuel. The fuel failure modes determining fuel life time were reviewed and fuel integrity was analyzed and compared with the failure criteria. Metal and nitride fuels with austenitic and ferritic stainless steel (SS) cladding tubes were examined in this study. For the purpose of representative irradiation behavior analyses of the fuel for Innovative Nuclear Energy Systems, the correlations of the cladding characteristics were modeled based on well-known characteristics of austenitic modified 316 SS (PNC316), ferritic–martensitic steel (PNC–FMS) and oxide dispersion strengthened steel (PNC–ODS). The analysis showed that the fuel lifetime is limited by channel fracture which is a nonductile type (brittle) failure associated with a high level of irradiation-induced swelling in the case of austenitic steel cladding. In case of ferritic steel, on the other hand, the fuel lifetime is controlled by cladding creep rupture. The lifetime evaluated here is limited to 200 GW d/t, which is lower than the target burnup value of 500 GW d/t. One of the possible measures to extend the lifetime may be reducing the fuel smeared density and ventilating fission gas in the plenum for metal fuel and by reducing the maximum cladding temperature from 650 to 600 °C for both metal and nitride fuel

An approach for evaluating the integrity of fuel applied in Innovative Nuclear Energy Systems

Energy Technology Data Exchange (ETDEWEB)

Nakae, Nobuo, E-mail: nakae-nobuo@jnes.go.jp [Center for Research into Innovative Nuclear Energy System, Tokyo Institute of Technology, 2-12-1-N1-19, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Ozawa, Takayuki [Advanced Nuclear System Research and Development Directorate, Japan Atomic Energy Agency, 4-33, Muramatsu, Tokai-mura, Ibaraki-ken 319-1194 (Japan); Ohta, Hirokazu; Ogata, Takanari [Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry, 2-11-1, Iwado Kita, Komae-shi, Tokyo 201-8511 (Japan); Sekimoto, Hiroshi [Center for Research into Innovative Nuclear Energy System, Tokyo Institute of Technology, 2-12-1-N1-19, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2014-03-15

One of the important issues in the study of Innovative Nuclear Energy Systems is evaluating the integrity of fuel applied in Innovative Nuclear Energy Systems. An approach for evaluating the integrity of the fuel is discussed here based on the procedure currently used in the integrity evaluation of fast reactor fuel. The fuel failure modes determining fuel life time were reviewed and fuel integrity was analyzed and compared with the failure criteria. Metal and nitride fuels with austenitic and ferritic stainless steel (SS) cladding tubes were examined in this study. For the purpose of representative irradiation behavior analyses of the fuel for Innovative Nuclear Energy Systems, the correlations of the cladding characteristics were modeled based on well-known characteristics of austenitic modified 316 SS (PNC316), ferritic–martensitic steel (PNC–FMS) and oxide dispersion strengthened steel (PNC–ODS). The analysis showed that the fuel lifetime is limited by channel fracture which is a nonductile type (brittle) failure associated with a high level of irradiation-induced swelling in the case of austenitic steel cladding. In case of ferritic steel, on the other hand, the fuel lifetime is controlled by cladding creep rupture. The lifetime evaluated here is limited to 200 GW d/t, which is lower than the target burnup value of 500 GW d/t. One of the possible measures to extend the lifetime may be reducing the fuel smeared density and ventilating fission gas in the plenum for metal fuel and by reducing the maximum cladding temperature from 650 to 600 °C for both metal and nitride fuel.

Safety analysis report for packaging (Oak Ridge Y-12 Plant Model DT-14A package for enriched uranium), Y/DD-326 Supplement No. 1 (Rev. 0)

International Nuclear Information System (INIS)

Cadelli, G.; Kennedy, W.R. Jr.

1986-01-01

This Supplement to the Safety Analysis Report Y/DD-326 [1.4.1] was prepared in accordance with US NRC Regulatory Guide 7.9 to address the Naval Fuel contents to be shipped in the DT-14A packaging. New chapters were written for Shielding, Critcality and Quality Assurance. Independent reviews were obtained for each of these chapters and for a product leakage analysis referenced in Chapter 7.0 of this document. Other chapters invoke the Y/DD-326 SARP with minor changes or additions as indicated in the Supplement. All references to form or composition of the fuel are classified Confidential NNPI in the interest of national security

Review of studies for thermonuclear ignition with 1.8 MJ laser (LMJ): theory and experiment

International Nuclear Information System (INIS)

Holstein, P.A.; Bastian, J.; Bowen, C.; Casanova, M.; Chaland, F.; Cherfils, C.; Dattolo, E.; Galmiche, D.; Gauthier, P.; Giorla, J.; Laffite, S.; Liberatore, S.; Loiseau, P.; Larroche, O.; Lours, L.; Malinie, G.; Masse, L.; Monteil, M.C.; Morice, O.; Paillard, D.; Poggi, F.; Saillard, Y.; Seytor, P.; Teychenne, D.; Vandenboomgaerde, M.; Wagon, F.; Bonnefille, M.; Hedde, T.; Lefebvre, E.; Riazuelo, G.; Babonneau, D.; Primout, M.; Casner, A.; Depierreux, S.; Girard, F.; Huser, G.; Jadaud, J.P.; Juraszek, D.; Miquel, J.L.; Naudy, M.; Philippe, F.; Rousseaux, C.; Videau, L.

2008-01-01

The purpose of the laser Megajoule (LMJ) is the ignition of thermonuclear fusion reactions in a microscopic capsule of cryogenic DT whose implosion is obtained by a laser pulse in the range of 10 -20 ns, delivering a power of 400 - 500 TW. In this report we have tried to gather in one document the main part of the work made from 1995 to 2005 by the teams of Cea/DAM to design the LMJ targets. This report deals with the targets adapted to the laser energy of 1.8 MJ corresponding to 60 laser beams (called quadruplets because of their 4 beamlets), so primarily, with the target called A1040. The targets studied more recently adapted to lower laser energy are too new to appear in it. It concerns all the topics of the physics of target LMJ: laser-plasma interaction, radiative budget of the hohlraum, implosion interaction, hydrodynamic instabilities and robustness of the target to the technological uncertainties. The approach made for the robustness study is original and makes it possible to specify the features of the laser and the targets. This review scans all the aspects of the target design done with numerical simulations of bi-dimensional radiative hydrodynamics but it points out also the main results of the experiments made with the lasers Phebus, Nova and Omega for 20 years. This review also addresses to scientist not specialists in the problems of inertial confinement fusion. It is organized by topics of physics and the experiments appear at the end of each chapter. It does not concern the aspects of target fabrication nor the problems of diagnostic. (authors)

Results of fuel management at Embalse nuclear power plant. Analysis of performance at other plants

International Nuclear Information System (INIS)

Paz, A.O. de; Moreno, C.A.; Vinez, J.C.

1987-01-01

The operating experience of fuel management at the Embalse nuclear power plant from new core to the present situation (approximately 937 days at full power) is described. The average core burnup is about 4000 MW d/t U and the monthly averaged discharge burnup about 7800 MW d/t U. The neutron flux distribution is calculated by means of program PUMA-C, which is periodically checked by comparison between calculated and measured values of 102 vanadium detectors. A comparison of the performance of other reactors type CANDU 600 (Point Lepreau, Gentilly 2, Wolsung) from the point of view of fuel strategy is also presented. The data to perform the comparison were obtained by means of the CANDU system of information exchange between users (COG). (Author)

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

Studies on muon cycling rates in muon catalyzed D-T fusion system with possible four-body muonic molecules formation

International Nuclear Information System (INIS)

Eskandri, M.R.; Hosini Motlagh, N.; Hataf, A.

2000-01-01

In recent studies, it is shown that the fusion rate for four-body molecules of ppμμ, ddμμ, ptμμ, pdμμ, dtμμ, ttμμ, is considerably larger than that of similar three-body molecules of ppμμ, ddμμ, ptμμ, pdμμ, dtμμ, ttμμ. It is shown that for dtμμ, fusion rate is R f (dt) ≅ 3 * 10 13 - 6 * * 10 13 S -1 which is 40 times higher than fusion rate of dtμμ molecule. In this paper we have looked for the effect of these molecules formation in muon catalyzed D-T fusion. The required data for all possible branches do not exist, so the main dtμμ branch are considered here. By choosing a variable value for dtμμ molecule formation rate and comparing obtained cycling rates with existing experimental values, the order of this parameter is evaluated to be ≅ 10 9 S -1 . Using obtained data in different conditions of D-T muon cycling rate calculations have shown that considering of four-body molecule formations in existing muon injection intensities do not make considerable change in three-body muonic molecule cycling rate

Concepts for fusion fuel production blankets

International Nuclear Information System (INIS)

Gierszewski, P.

1986-06-01

The fusion blanket surrounds the burning hydrogen core of the fusion reactor. It is in this blanket that most of the energy released by the DT fusion reaction is converted into useable product, and where tritium fuel is produced to enable further operation of the reactor. Blankets will involve new materials, conditions and processes. Several recent fusion blanket concepts are presented to illustrate the range of ideas

Enhancement of hypermutation frequency in the chicken B cell line DT40 for efficient diversification of the antibody repertoire

Energy Technology Data Exchange (ETDEWEB)

Magari, Masaki; Kanehiro, Yuichi; Todo, Kagefumi; Ikeda, Mika; Kanayama, Naoki, E-mail: nkanayama@cc.okayama-u.ac.jp; Ohmori, Hitoshi

2010-05-28

Chicken B cell line DT40 continuously accumulates mutations in the immunoglobulin variable region (IgV) gene by gene conversion and point mutation, both of which are mediated by activation-induced cytidine deaminase (AID), thereby producing an antibody (Ab) library that is useful for screening monoclonal Abs (mAbs) in vitro. We previously generated an engineered DT40 line named DT40-SW, whose AID expression can be reversibly switched on or off, and developed an in vitro Ab generation system using DT40-SW cells. To efficiently create an Ab library with sufficient diversity, higher hypermutation frequency is advantageous. To this end, we generated a novel cell line DT40-SW{Delta}C, which conditionally expresses a C-terminus-truncated AID mutant lacking the nuclear export signal. The transcription level of the mutant AID gene in DT40-SW{Delta}C cells was similar to that of the wild-type gene in DT40-SW cells. However, the protein level of the truncated AID mutant was less than that of the wild type. The mutant protein was enriched in the nuclei of DT40-SW{Delta}C cells, although the protein might be highly susceptible to degradation. In DT40-SW{Delta}C cells, both gene conversion and point mutation occurred in the IgV gene with over threefold higher frequency than in DT40-SW cells, suggesting that a lower level of the mutant AID protein was sufficient to increase mutation frequency. Thus, DT40-SW{Delta}C cells may be useful for constructing Ab libraries for efficient screening of mAbs in vitro.

Review of recent D-T experiments from TFTR

International Nuclear Information System (INIS)

Hawryluk, R.J.; Adler, H.; Alling, P.; Ancher, C.; Anderson, H.; Anderson, J.W.; Arunasalam, V.; Ascione, G.; Ashcroft, D.; Barnes, G.; Bateman, G.

1995-01-01

An extensive set of deuterium-tritium (D-T) experiments has been carried out on the Tokamak Fusion Test Reactor (TFTR), using nearly equal concentrations of deuterium and tritium. The fusion power has been increased to 9.3 MW, using 34 MW of neutral-beam heating, in a supershot discharge and to 6.7 MW in a high-pp discharge following a current rampdown. Extensive lithium pellet injection has increased the confinement time to 0.27 s and enabled higher current operation in both supershot and high-pp discharges. The energy confinement time, τ E , was observed to increase in D-T, relative to D plasmas, by 20% and the n i (0)Ti(0)τ E product by 55%. The improvement in thermal confinement was caused primarily by a decrease in ion heat conductivity in both supershot and limiter-H-mode discharges. ICRF heating of a D-T plasma, using the second harmonic of tritium, has been demonstrated. First measurements of the confined alpha particles have been performed and found to be in good agreement with TRANSP simulations. Initial measurements of the alpha ash profile have been compared with simulations using particle transport coefficients from He gas puffing experiments. The loss of alpha particles to a detector at the bottom of the vessel is well described by the first-orbit loss mechanism. No loss due to alpha-particle-driven instabilities has yet been observed. The TFIR experiments were able to challenge and confirm several of the underlying assumptions of the ITER design

Quasiresonant formation of dtμ mesic molecules in triple collisions

International Nuclear Information System (INIS)

Men'shikov, L.I.; Ponomarev, L.I.

1985-01-01

A quasiresonant mechanism of mesic molecules formation, in triple collisions of the type tμ+D 2 +D 2 → [(dtμ)d2e] * +D ν is considered. It is shown that at small resonance defects and big D 2 +T 2 mixture densities φ the rate of this process λ qr ∼ φ 2 and it is comparable with the rate λ r ∼ φ of the mesic molecules resonant formation in the reactions of the type tμ+D 2 → [(dtμ)d2e] ν *. The observable manifestations of the process considered and its role in the muon catalyzed fusion in deuterium-tritium mixture are discussed

TFTR neutral beam control and monitoring for DT operations

International Nuclear Information System (INIS)

O'Connor, T.; Kamperschroer, J.; Chu, J.

1995-01-01

Record fusion power output has recently been obtained in TFTR with the injection of deuterium and tritium neutral beams. This significant achievement was due in part to the controls, software, and data processing capabilities added to the neutral beam system for DT operations. Chief among these improvements was the addition of SUN workstations and large dynamic data storage to the existing Central Instrumentation Control and Data Acquisition (CICADA) system. Essentially instantaneous look back over the recent shot history has been provided for most beam waveforms and analysis results. Gas regulation controls allowing remote switchover between deuterium and tritium were also added. With these tools, comparison of the waveforms and data of deuterium and tritium for four test conditioning pulses quickly produced reliable tritium setpoints. Thereafter, all beam conditioning was performed with deuterium, thus saving the tritium supply for the important DT injection shots. The lookback capability also led to modifications of the gas system to improve reliability and to control ceramic valve leakage by backbiasing. Other features added to improve the reliability and availability of DT neutral beam operations included master beamline controls and displays, a beamline thermocouple interlock system, a peak thermocouple display, automatic gas inventory and cryo panel gas loading monitoring, beam notching controls, a display of beam/plasma interlocks, and a feedback system to control beam power based on plasma conditions

Magnetic Reconnection Driven by Thermonuclear Burning

Science.gov (United States)

Gatto, R.; Coppi, B.

2017-10-01

Considering that fusion reaction products (e.g. α-particles) deposit their energy on the electrons, the relevant thermal energy balance equation is characterized by a fusion source term, a relatively large longitudinal thermal conductivity and an appropriate transverse thermal conductivity. Then, looking for modes that are radially localized around rational surfaces, reconnected field configurations are found that can be sustained by the electron thermal energy source due to fusion reactions. Then this process can be included in the category of endogenous reconnection processes and may be viewed as a form of the thermonuclear instability that can develop in an ignited inhomogeneous plasma. A complete analysis of the equations supporting the relevant theory is reported. Sponsored in part by the U.S. DoE.

Continuously renewed wall for a thermonuclear reactor

International Nuclear Information System (INIS)

Livshits, A.I.; Pustovojt, YU.M.; Samartsev, A.A.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii)

1982-01-01

The possibility of creating a continuously renewed first wall of a thermonuclear reactor is experimentally investigated. The following variants of the wall are considered: the wall is double, its part turned to plasma is made of comparatively thin material. The external part separated from it by a small gap appears to be protected from interaction with plasma and performs structural functions. The gap contains the mixture of light helium and hydrogen and carbon-containing gas. The light gas transfers heat from internal part of the wall to the external part. Carbon-containing gas provides continuous renewal of carbon coating of the operating surface. The experiment is performed with palladium membrane 20 μm thick. Carbon is introduced into the membrane by benzol pyrolysis on one of the surfaces at the membrane temperature of 900 K. Carbon removal from the operating side of the wall due to its spraying by fast particles is modelled by chemical itching with oxygen given to the operating membrane wall. Observation of the carbon release on the operating surface is performed mass-spectrometrically according to the observation over O 2 transformation into CO and CO 2 . It is shown that in cases of benzol pressure of 5x10 -7 torr, carbon current on the opposite surface is not less than 3x10 12 atoms/sm 2 s and corresponds to the expected wall spraying rate in CF thermonuclear reactors. It is also shown that under definite conditions the formation and maintaining of a through protective carbon coating in the form of a monolayer or volumetric phase is possible

Ratcheting problems for ITER [International Thermonuclear Experimental Reactor

International Nuclear Information System (INIS)

Majumdar, S.

1991-01-01

Because of the presence of high cyclic thermal stress, pressure-induced primary stress, and disruption-induced high cyclic primary stress, ratcheting of the first wall poses a serious challenge to the designers of ITER (International Thermonuclear Experimental Reactor). Existing design tools such as the Bree diagram in the ASME Boiler and Pressure Vessels Code, are not directly applicable to ITER, because of important differences in geometry and loading modes. Available alternative models for ratcheting are discussed and new Bree diagrams, that are more relevant for fusion reactor applications, are proposed. 9 refs., 17 figs

Department of Thermonuclear Research annual report 1993

International Nuclear Information System (INIS)

Sadowski, M.; Pawlowicz, W.

1994-01-01

Department of Thermonuclear Research Annual Report 1993 presents a short review of theoretical, experimental and technological studies performed within the framework of the research program - Plasma Physics. Theoretical studies of a tokamak edge plasma, inner shell ionization by positrons, heat transfer in thin foils, and numerical simulation of HV pulse generators, are summarized. Experimental studies of X-rays and charged particles (including fusion protons) emitted from Plasma-Focus facilities, as well as measurements of plasma-ion streams generated by IONOTRON devices, are described shortly. Also presented are technological studies on data acquisition systems and material engineering, in particular the modification of solid surfaces with the plasma-ion streams. (author)

Department of Thermonuclear Research. Annual report 1988

International Nuclear Information System (INIS)

Sadowski, M.

1989-01-01

Department of Thermonuclear Research annual report 1988 presents a short review of theoretical, experimental and technological studies performed within a framework of two research programs: diagnostics of high-temperature plasma and nuclear technology. We describe theoretical investigations on the modelling of Tokamak edge plasmas, ion motions, atomic collisions, high-voltage electrode systems and plasma-focus (PF) facilities. The experimental studies on plasma-ion streams, high-current discharges of the PF-type, and on the interaction of ion beams with gaseous targets, are shortly summarized. Also presented are technological studies on electronic and high-voltage systems, as well as applications of the IONOTRON type plasma devices. (author)

Department of Thermonuclear Research annual report 1993

Energy Technology Data Exchange (ETDEWEB)

Sadowski, M; Pawlowicz, W [eds.; Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

1994-12-31

Department of Thermonuclear Research Annual Report 1993 presents a short review of theoretical, experimental and technological studies performed within the framework of the research program - Plasma Physics. Theoretical studies of a tokamak edge plasma, inner shell ionization by positrons, heat transfer in thin foils, and numerical simulation of HV pulse generators, are summarized. Experimental studies of X-rays and charged particles (including fusion protons) emitted from Plasma-Focus facilities, as well as measurements of plasma-ion streams generated by IONOTRON devices, are described shortly. Also presented are technological studies on data acquisition systems and material engineering, in particular the modification of solid surfaces with the plasma-ion streams. (author).

Gamma-ray emission spectrum from thermonuclear fusion reactions without intrinsic broadening

DEFF Research Database (Denmark)

Nocente, M.; Källne, J.; Salewski, Mirko

2015-01-01

First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution instrume......First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution...... instruments. An analytical formula for the spectrum from Maxwellian plasmas, which extends to higher temperatures than the results previously available in the literature, has been derived and used to discuss the assumptions and limitations of earlier models. In case of radio-frequency injection, numerical...... results based on a Monte Carlo method are provided, focusing in particular on improved relations between the peak shift and width from the reaction and the temperature of protons accelerated by radio-frequency heating.The results presented in this paper significantly improve the accuracy of diagnostic...

International research co-operation in the field of controlled thermonuclear fusion

International Nuclear Information System (INIS)

2004-01-01

This 26th report by the Swiss Federal Office for Education and Science presents a review of work done in Swiss institutes in 2003 as part of international research into thermonuclear fusion. A broad outline of the project and of its significance within the wider field of thermonuclear fusion research is given. This is followed by a review of the significant events in the world of fusion research, with emphasis placed on ITER and on the EURATOM fusion programme. A further chapter summarises events in Switzerland in 2003 and the report closes with a list of contacts for more information. Three annexes provide information on the current situation in fusion research, as well as scientific and technical highlights of the work performed in 2003 at the Plasma Physics Research Centre CRPP at the Federal Institute of Technology EPFL in Lausanne, Switzerland. Annex 3 reports on results obtained at the Physics Institute of the University of Basle. The annexes are for the benefit of the technically and scientifically versed reader, and brief summaries of them are given in the main body of the report

The Canadian initiative to bring the international thermonuclear experimental reactor to Canada

International Nuclear Information System (INIS)

James, R.A.

1996-01-01

The International Thermonuclear Experimental Reactor (ITER) is the next step in fusion research. It is expected to be the last major experimental facility, before the construction of a prototype commercial reactor. The Engineering Design Activities (EDA) of ITER are being funded by the USA, Japan, the Russian Federation, and the European Union, with each of the major parties contributing about 25% of the cost. Canada participates as part of the European coalition. The EDA is due to be completed in 1998, and the major funding partners are preparing for the decision on the siting and construction of ITER. The Canadian Fusion Fuels Technology Project (CFFTP) formed a Canadian ITER Siting Task Group to study siting ITER in Canada. The study indicated that hosting ITER would provide significant benefits, both technological and economic, to Canada. We have also confirmed that there would be substantial benefits to the ITER Project. CFFTP then formed a Canadian ITER Siting Board, with representation from a broad range of stakeholders, to champion, 'Canada as Host'. This paper briefly outlines the ITER Project, and the benefits to both Canada and the Project of a Canadian site. With this as background, the paper discusses the international scene and assesses Canada's prospects of being chosen to host ITER. (author)

The intensive DT neutron generator of TU Dresden

Directory of Open Access Journals (Sweden)

Klix Axel

2018-01-01

Full Text Available TU Dresden operates an accelerator-based intensive DT neutron generator. Experimental activities comprise investigation into material activation and decay, neutron and photon transport in matter and R&D work on radiation detectors for harsh environments. The intense DT neutron generator is capable to produce a maximum of 1012 n/s. The neutron source is a solid-type water-cooled tritium target based on a titanium matrix on a copper carrier. The neutron yield at a typical deuteron beam current of 1 mA is of the order of 1011 n/s in 4Π. A pneumatic sample transport system is available for short-time irradiations and connected to wo high-purity germanium detector spectrometers for the measurement of induced activities. The overall design of the experimental hall with the neutron generator allows a flexible setup of experiments including the possibility of investigating larger structures and cooled samples or samples at high temperatures.

The intensive DT neutron generator of TU Dresden

Science.gov (United States)

Klix, Axel; DÖring, Toralf; Domula, Alexander; Zuber, Kai

2018-01-01

TU Dresden operates an accelerator-based intensive DT neutron generator. Experimental activities comprise investigation into material activation and decay, neutron and photon transport in matter and R&D work on radiation detectors for harsh environments. The intense DT neutron generator is capable to produce a maximum of 1012 n/s. The neutron source is a solid-type water-cooled tritium target based on a titanium matrix on a copper carrier. The neutron yield at a typical deuteron beam current of 1 mA is of the order of 1011 n/s in 4Π. A pneumatic sample transport system is available for short-time irradiations and connected to wo high-purity germanium detector spectrometers for the measurement of induced activities. The overall design of the experimental hall with the neutron generator allows a flexible setup of experiments including the possibility of investigating larger structures and cooled samples or samples at high temperatures.

Fusion reactor fuel processing

International Nuclear Information System (INIS)

Johnson, E.F.

1972-06-01

For thermonuclear power reactors based on the continuous fusion of deuterium and tritium the principal fuel processing problems occur in maintaining desired compositions in the primary fuel cycled through the reactor, in the recovery of tritium bred in the blanket surrounding the reactor, and in the prevention of tritium loss to the environment. Since all fuel recycled through the reactor must be cooled to cryogenic conditions for reinjection into the reactor, cryogenic fractional distillation is a likely process for controlling the primary fuel stream composition. Another practical possibility is the permeation of the hydrogen isotopes through thin metal membranes. The removal of tritium from the ash discharged from the power system would be accomplished by chemical procedures to assure physiologically safe concentration levels. The recovery process for tritium from the breeder blanket depends on the nature of the blanket fluids. For molten lithium the only practicable possibility appears to be permeation from the liquid phase. For molten salts the process would involve stripping with inert gas followed by chemical recovery. In either case extremely low concentrations of tritium in the melts would be desirable to maintain low tritium inventories, and to minimize escape of tritium through unwanted permeation, and to avoid embrittlement of metal walls. 21 refs

Radiation shielding design of BNCT treatment room for D-T neutron source.

Science.gov (United States)

Pouryavi, Mehdi; Farhad Masoudi, S; Rahmani, Faezeh

2015-05-01

Recent studies have shown that D-T neutron generator can be used as a proper neutron source for Boron Neutron Capture Therapy (BNCT) of deep-seated brain tumors. In this paper, radiation shielding calculations have been conducted based on the computational method for designing a BNCT treatment room for a recent proposed D-T neutron source. By using the MCNP-4C code, the geometry of the treatment room has been designed and optimized in such a way that the equivalent dose rate out of the treatment room to be less than 0.5μSv/h for uncontrolled areas. The treatment room contains walls, monitoring window, maze and entrance door. According to the radiation protection viewpoint, dose rate results of out of the proposed room showed that using D-T neutron source for BNCT is safe. Copyright © 2015 Elsevier Ltd. All rights reserved.

An outbreak of multidrug-resistant, quinolone-resistant Salmonella enterica serotype typhimurium DT104

DEFF Research Database (Denmark)

Molbak, K.; Baggesen, Dorte Lau; Aarestrup, Frank Møller

1999-01-01

Background Food-borne salmonella infections have become a major problem in industrialized countries. The strain of Salmonella enterica serotype typhimurium known as definitive phage type 104 (DT104) is usually resistant to five drugs: ampicillin, chloramphenicol, streptomycin, sulfonamides......, and tetracycline. An increasing proportion of DT104 isolates also have reduced susceptibility to fluoroquinolones. Methods The Danish salmonella surveillance program determines the phage types of all typhimurium strains from the food chain, and in the case of suspected outbreaks, five-drug-resistant strains...... are characterized by molecular methods. All patients infected with five-drug-resistant typhimurium are interviewed to obtain clinical and epidemiologic data. In 1998, an outbreak of salmonella occurred, in which the strain of typhimurium DT104 was new to Denmark. We investigated this outbreak and report our...

Pellet injector development at ORNL [Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Gouge, M.J.; Argo, B.E.; Baylor, L.R.; Combs, S.K.; Fehling, D.T.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Milora, S.L.; Qualls, A.L.; Schechter, D.E.; Simmons, D.W.; Sparks, D.O.; Tsai, C.C.

1990-01-01

Advanced plasma fueling systems for magnetic confinement experiments are under development at Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogenic pellets to speeds in the kilometer-per-second range by either pneumatic (light-gas gun) or mechanical (centrifugal force) techniques. ORNL has recently provided a centrifugal pellet injector for the Tore Supra tokamak and a new, simplified, eight-shot pneumatic injector for the Advanced Toroidal Facility stellarator at ORNL. Hundreds of tritium and DT pellets were accelerated at the Tritium Systems Test Assembly facility at Los Alamos in 1988--89. These experiments, done in a single-shot pipe-gun system, demonstrated the feasibility of forming and accelerating tritium pellets at low 3 He levels. A new, tritium-compatible extruder mechanism is being designed for longer-pulse DT applications. Two-stage light-gas guns and electron beam rocket accelerators for speeds of the order of 2--10 km/s are also under development. Recently, a repeating, two-stage light-gas gun accelerated 10 surrogate pellets at a 1-Hz repetition rate to speeds in the range of 2--3 km/s; and the electron beam rocket accelerator completed initial feasibility and scaling experiments. ORNL has also developed conceptual designs of advanced plasma fueling systems for the Compact Ignition Tokamak and the International Thermonuclear Experimental Reactor

Noninvasive assessment of left atrial maximum dP/dt by a combination of transmitral and pulmonary venous flow.

Science.gov (United States)

Nakatani, S; Garcia, M J; Firstenberg, M S; Rodriguez, L; Grimm, R A; Greenberg, N L; McCarthy, P M; Vandervoort, P M; Thomas, J D

1999-09-01

The study assessed whether hemodynamic parameters of left atrial (LA) systolic function could be estimated noninvasively using Doppler echocardiography. Left atrial systolic function is an important aspect of cardiac function. Doppler echocardiography can measure changes in LA volume, but has not been shown to relate to hemodynamic parameters such as the maximal value of the first derivative of the pressure (LA dP/dt(max)). Eighteen patients in sinus rhythm were studied immediately before and after open heart surgery using simultaneous LA pressure measurements and intraoperative transesophageal echocardiography. Left atrial pressure was measured with a micromanometer catheter, and LA dP/dt(max) during atrial contraction was obtained. Transmitral and pulmonary venous flow were recorded by pulsed Doppler echocardiography. Peak velocity, and mean acceleration and deceleration, and the time-velocity integral of each flow during atrial contraction was measured. The initial eight patients served as the study group to derive a multilinear regression equation to estimate LA dP/dt(max) from Doppler parameters, and the latter 10 patients served as the test group to validate the equation. A previously validated numeric model was used to confirm these results. In the study group, LA dP/dt(max) showed a linear relation with LA pressure before atrial contraction (r = 0.80, p LA. Among transmitral flow parameters, mean acceleration showed the strongest correlation with LA dP/dt(max) (r = 0.78, p LA dP/dt(max) with an r2 > 0.30. By stepwise and multiple linear regression analysis, LA dP/dt(max) was best described as follows: LA dP/dt(max) = 0.1 M-AC +/- 1.8 P-V - 4.1; r = 0.88, p LA dP/dt(max) correlated well (r = 0.90, p LA dP/dt(max) predicted by the above equation with r = 0.94. A combination of transmitral and pulmonary venous flow parameters can provide a hemodynamic assessment of LA systolic function.

Laser fusion experiments at 2 TW

International Nuclear Information System (INIS)

Storm, E.K.; Ahlstrom, H.G.; Boyle, M.J.

1976-01-01

The Lawrence Livermore Laboratory Solid State Laser System, Argus, has successfully performed laser implosion experiments at power levels exceeding 2 TW. D-T filled glass microspheres have been imploded to yield thermonuclear reaction products in excess of 5 x 10 8 per event. Neutron and α time-of-flight measurements indicate that D-T ion temperatures of approximately 5 to 6 keV and a density confinement time product (n tau) of approximately 1 x 10 12 were obtained in these experiments. Typically two 40J, 40 psec pulses of 1.06 μm light were focused on targets using 20 cm aperture f/l lenses, producing intensities at the target in excess of 10 16 W/cm 2 . An extensive array of diagnostics routinely monitored the laser performance and the laser target interaction process. Measurements of absorption and asymmetry in both the scattered light distribution and the ion blow off is evidence for non-classical absorption mechanisms and density scale heights of the order of 2 μm or less. The symmetry of the thermonuclear burn region is investigated by monitoring the α-particle flux in several directions, and an experiment to image the thermonuclear burn region is in process. These experiments significantly extend our data base and our understanding of laser induced thermonuclear implosions and the basic laser plasma interaction physics from the 0.4 to 0.7 TW level of previous experiments

Laser fusion experiments at 2 TW

International Nuclear Information System (INIS)

Storm, E.K.; Ahlstrom, H.G.; Boyle, M.J.

1976-01-01

The Lawrence Livermore Laboratory Solid State Laser System, Arqus, has successfully performed laser implosion experiments at power levels exceeding 2 TW. D-T filled glass microspheres have been imploded to yield thermonuclear reaction products in excess of 5 x 10 8 per event. Neutron and α time-of-flight measurements indicate that D-T ion temperatures of approximately 5-6 keV and a density confinement time product (n tau) of approximately 1 x 10 12 were obtained in these experiments. Typically two 40J, 40 psec pulses of 1.06 μm light were focused on targets using 20 cm aperture f/1 lenses, producing intensities at the target in excess of 10 16 W/cm 2 . An extensive array of diagnostics routinely monitored the laser performance and the laser target interaction process. Measurements of absorption and asymmetry in both the scattered light distribution and the ion blow off is evidence for non-classical absorption mechanisms and density scale heights of the order of 2 μm or less. The symmetry of the thermonuclear burn region is investigated by monitoring the α-particle flux in several directions, and an experiment to image the thermonuclear burn region is in process. These experiments significantly extend our data base and our understanding of laser induced thermonuclear implosions and the basic laser plasma interaction physics from the 0.4 to 0.7 TW level of previous experiments

Surface effects in controlled thermonuclear fusion

International Nuclear Information System (INIS)

Kaminsky, M.

1975-08-01

During the operation of large size plasma facilities and future controlled thermonuclear fusion reactors the surfaces of such major components as container walls, beam limiters, diverter walls and beam-dump walls of the injector region will be exposed to particle and photon bombardment from primary plasma radiations and from secondary radiations. Such radiations can cause, for example, physical and chemical sputtering, blistering, particle- and photon-impact induced desorption, secondary electron and x-ray emission, backscattering, nuclear reactions, photo-decomposition of surface compounds, photocatalysis, and vaporization. Such effects in turn can (a) seriously damage and erode the bombarded surface and (b) release major quantities of impurities which will contaminate the plasma. The effects of some of the major surface phenomena on the operation of plasma facilities and future fusion reactors are discussed

MUON DETECTORS: DT

CERN Multimedia

M. Dallavalle

2013-01-01

The DT collaboration is undertaking substantial work both for detector maintenance – after three years since the last access to the chambers and their front-end electronics – and upgrade. The most critical maintenance interventions are chambers and Minicrate repairs, which have not begun yet, because they need proper access to each wheel of the CMS barrel, meaning space for handling the big chambers in the few cases where they have to be extracted, and, more in general, free access from cables and thermal shields in the front and back side of the chambers. These interventions are planned for between the coming Autumn until next spring. Meanwhile, many other activities are happening, like the “pigtail” intervention on the CAEN AC/DC converters which has just taken place. The upgrade activities continue to evolve in good accordance with the schedule, both for the theta Trigger Board (TTRB) replacement and for the Sector Collector (SC) relocation from the UXC to the US...

Cooling device in thermonuclear device

International Nuclear Information System (INIS)

Honda, Tsutomu.

1988-01-01

Purpose: To prevent loss of cooling effect over the entire torus structure directly after accidental toubles in a cooling device of a thermonuclear device. Constitution: Coolant recycling means of a cooling device comprises two systems, which are alternately connected with in-flow pipeways and exit pipeways of adjacent modules. The modules are cooled by way of the in-flow pipeways and the exist pipeways connected to the respective modules by means of the coolant recycling means corresponding to the respective modules. So long as one of the coolant recycling means is kept operative, since every one other modules of the torus structure is still kept cooled, the heat generated from the module put therebetween, for which the coolant recycling is interrupted, is removed by means of heat conduction or radiation from the module for which the cooling is kept continued. No back-up emergency cooling system is required and it can provide high economic reliability. (Kamimura, M.)

First wall of thermonuclear device

International Nuclear Information System (INIS)

Miki, Nobuharu.

1992-01-01

In a first wall of a thermonuclear device, armour tiles are metallurgically bonded to a support substrate only for the narrow area of the central portion thereof, while bonded by metallurgical bonding with cooling tubes of low mechanical toughness, separated from each other in other regions. Since the bonding area with the support substrate of great mechanical rigidity is limited to the narrow region at the central portion of the armour tiles, cracking are scarcely caused at the end portion of the bonding surface. In other regions, since cooling tubes of low mechanical rigidity are bonded metallurgically, they can be sufficiently withstand to high thermal load. That is, even if the armour tiles are deformed while undergoing thermal load from plasmas, since the cooling tubes absorb it, there is no worry of damaging the metallurgically bonded face. Since the cooling tubes are bonded directly to the armour tiles, they absorb the heat of the armour tiles efficiently. (N.H.)

Fueling by liquid jets

International Nuclear Information System (INIS)

Bruno, C.

1978-01-01

Maintenance of steady-state burn in tokamak fusion reactors will require a reliable method for fueling them during operation. The injection of high-velocity dense-phase DT is one solution under investigation. The eventual requirements are not known precisely but the next series of experiments in tokamak devices (e.g., Doublet III, PDX) could use millimeter size particles with velocities of the order of 2000 m/s. This paper presents results on the feasibility of a high-pressure injection system to meet these objectives

Transition to thermonuclear burn in fusion plasmas

International Nuclear Information System (INIS)

Anderson, D.; Hamnen, H.; Lisak, M.

1991-01-01

An analytical investigation is made of the time evolution of the 1-D temperature profile in a fusion reactor plasma where the nonlinear energy balance equation is dominated by alpha-particle heating and thermal conduction losses. Special emphasis is given to the problem of establishing sufficient conditions for the transition to thermonuclear burn for given initial temperature profiles. In particular, it is demonstrated that for strongly nonlinear alpha-particle heating, temperature profiles initially peaked on-axis are more easily ignited than profiles similar in form to the equilibrium profile of the energy balance equation. Simple analytical criteria for ignition are established and are shown to compare favourably with results of numerical calculations. (author)

Puzzling thermonuclear burst behaviour from the transient low-mass X-ray binary IGR J17473-2721

DEFF Research Database (Denmark)

Chenevez, Jérôme

2010-01-01

We investigate the thermonuclear bursting behaviour of IGR J17473-2721, an X-ray transient that in 2008 underwent a six month long outburst, starting (unusually) with an X-ray burst. We detected a total of 57 thermonuclear bursts throughout the outburst with AGILE, Swift, RXTE, and INTEGRAL...... it dropped (at a persistent flux corresponding to 15%of m˙ Edd) a few days before the outburst peak, after which bursts were not detected for a month. As the persistent emission subsequently decreased, the bursting activity resumed at a much lower rate than during the outburst rise. This hysteresis may arise...... produced a similar quenching of burst activity....

First evidence of collective alpha particle effect on TAE modes in the TFTR D-T experiment

International Nuclear Information System (INIS)

Wong, K.L.; Schmidt, G.; Batha, S.H.

1995-08-01

The alpha particle effect on the excitation of toroidal Alfven eigenmodes (TAE) was investigated in deuterium-tritium (d-t) plasmas in the Tokamak Fusion Test Reactor (TFTR). RF power was used to position the plasma near the instability threshold, and the alpha particle effect was inferred from the reduction of RF power threshold for TAE instability in d-t plasmas. Initial calculations indicate that the alpha particles contribute 10--30% of the total drive in a d-t plasma with 3 MW of peak fusion power

The role of materials in controlled thermonuclear research

Energy Technology Data Exchange (ETDEWEB)

Craston, J L; Hancox, R; Robson, A E [U.K. Atomic Energy Authority, AERE, Harwell (United Kingdom); Kaufman, S; Miles, H T; Ware, A A; Wesson, J A [AEI Research Laboratory, Aldermaston (United Kingdom)

1958-07-01

It is the purpose of this paper to examine the processes occurring at the wall and to discuss their importance in the choice of materials both for present equipment and for future designs. The emphasis is laid primarily on plasma contamination but other effects are considered, such as thermal stress fatigue and radiation damage of the wall. The principal problems associated with the choice of wall material for a high current discharge tube have been discussed, both under the conditions which exist in present systems and under the conditions which are anticipated in a thermonuclear reactor.

Thermonuclear reaction rates in a deuterium-tritium plasma

International Nuclear Information System (INIS)

Beckman, L.

1978-12-01

In a deuterium-tritium plasma six thermonuclear reactions take place between the deuterons, tritons and the 3 He-particles formed in about half of the d-d-reactions. The rate constants for these six reactions have been calculated from the latest evaluations of the reaction cross sections which were available. In some cases, notably the reactions t+t, t+ 3 He and 3 He+ 3 He, the number of published cross section measurements is small, and the uncertainty in the calculated rate constants consequently large. Analytical expressions for the rate constants as functions of the plasma temperature have been set up. (author)

Controlled thermonuclear fusion and the latest progress on China's HT-7 superconducting tokamak

International Nuclear Information System (INIS)

Li Jiangang; Yang Yu

2003-01-01

After 50 years of research on controlled thermonuclear fusion, a new stage will be reached in 2003, when a site for the International Thermonuclear Experimental Reactor project will be chosen to start the construction. Scientists hope that this project could herald a new era in which the energy problem will be solved completely. The great progress made on the HT-7 superconducting tokamak in China has provided positive and powerful support for fusion research. The HT-7 is one of the only two superconducting tokamaks in the world that can carry out minute-scale high temperature plasma research, and has achieved a duration of 63.95s for the hot plasma discharge. This is a major step towards real steady-state operation of the tokamak configuration. We present an overview of the latest progress on the tokamak experiments in the Institute of Plasma Physics, Chinese Academy of Sciences

Non-thermal DT yield with (D)T ICRH heating in JET

International Nuclear Information System (INIS)

Cotrell, G.A.; Bhatnagar, V.B.; Bures, M.; Hellsten, T.; Jacquinot, J.; Start, D.F.H.

1989-01-01

We present projections of the (D)T fusion yield expected during fundamental ICRH heating of D in JET plasmas. To obtain high Q, one needs to use a relatively high plasma density (n e > 5x10 19 m -3 ) and dipole antenna (k≅ 10%-30%), we have used ray-tracing and global wave ICRH codes to estimate cyclotron damping on deuterium (∼80%) and the rf power coupled directly to electrons (∼17%) via TTMP and Landau damping. With launched rf power P rf =12 MW deposited ∼0.3 m off-axis, we predict fusion powers P fus up to ∼8 MW for a range of JET plasmas with achieved plasma pressure n e o T e o = 6x10 20 keV m -3 and Z eff = 2. Projecting to P c = 20 MW, P fus increases to 17 MW with Z eff = 2. (author) 10 refs., 4 figs

Recent D-T results on TFTR

International Nuclear Information System (INIS)

Johnson, D.W.; Arunasalam, V.

1995-10-01

Routine tritium operation in TFTR has permitted investigations of alpha particle physics in parameter ranges resembling those of a reactor core. ICRF wave physics in a DT plasma and the influence of isotopic mass on supershot confinement have also been studied. Continued progress has been made in optimizing fusion power production in TFTR, using extended machine capability and Li wall conditioning. Performance is currently limited by MHD stability. A new reversed magnetic shear regime is being investigated with reduced core transport and a higher predicted stability limit

Sensitivity of ICF ignition conditions to non-Maxwellian DT fusion reactivity

International Nuclear Information System (INIS)

Garbett, W. J.

2013-01-01

The hotspot ignition conditions in ICF are determined by considering the power balance between fusion energy deposition and energy loss terms. Uncertainty in any of these terms has potential to modify the ignition conditions, changing the optimum ignition capsule design. This paper considers the impact of changes to the DT fusion reaction rate due to non-thermal ion energy distributions. The DT fusion reactivity has been evaluated for a class of non-Maxwellian distributions representing a perturbation to the tail of a thermal distribution. The resulting reactivity has been used to determine hotspot ignition conditions as a function of the characteristic parameter of the modified distribution. (authors)

Interpolation of vector fields from human cardiac DT-MRI

International Nuclear Information System (INIS)

Yang, F; Zhu, Y M; Rapacchi, S; Robini, M; Croisille, P; Luo, J H

2011-01-01

There has recently been increased interest in developing tensor data processing methods for the new medical imaging modality referred to as diffusion tensor magnetic resonance imaging (DT-MRI). This paper proposes a method for interpolating the primary vector fields from human cardiac DT-MRI, with the particularity of achieving interpolation and denoising simultaneously. The method consists of localizing the noise-corrupted vectors using the local statistical properties of vector fields, removing the noise-corrupted vectors and reconstructing them by using the thin plate spline (TPS) model, and finally applying global TPS interpolation to increase the resolution in the spatial domain. Experiments on 17 human hearts show that the proposed method allows us to obtain higher resolution while reducing noise, preserving details and improving direction coherence (DC) of vector fields as well as fiber tracking. Moreover, the proposed method perfectly reconstructs azimuth and elevation angle maps.

Obtaining the neutron time-of-flight instrument response function for a single D-T neutron utilizing n-alpha coincidence from the d(t, α) n nuclear reaction

Science.gov (United States)

Styron, Jedediah; Ruiz, Carlos; Hahn, Kelly; Cooper, Gary; Chandler, Gordon; Jones, Brent; McWatters, Bruce; Smith, Jenny; Vaughan, Jeremy

2017-10-01

A measured neutron time-of-flight (nTOF) signal is a convolution of the neutron reaction history and the instrument response function (IRF). For this work, the IRF was obtained by measuring single, D-T neutron events by utilizing n-alpha coincidence. The d(t, α) n nuclear reaction was produced at Sandia National Laboratories' Ion Beam Laboratory using a 300-keV Cockroft-Walton generator to accelerate a 2- μA beam, of 175-keV D + ions, into a stationary, 2.6- μm, ErT2 target. Comparison of these results to those obtained using cosmic-rays and photons will be discussed. Sandia National Laboratories.

Status report on controlled thermonuclear fusion

International Nuclear Information System (INIS)

1990-01-01

The International Fusion Research Council has prepared this report on the current status of fusion, an update of its 1978 report, at the request of the Director General of the International Atomic Energy Agency. The report consists of an introductory note by the Director General, an Executive Summary and General Overview published in this document, and a series of technical reports. The background of fusion as an energy source is documented and compared with fission. The two approaches to thermonuclear fusion, magnetic confinement and inertial confinement, are discussed. The viability with respect to economic, environmental, and safety aspects is discussed. Fusion programs in the European Community, Japan, the USSR, the USA, as well as smaller programs in other countries are described. The status of fusion physics and technology is elucidated, and future directions and plans are indicated. 5 refs, 6 figs

Impacts of Implosion Asymmetry And Hot Spot Shape On Ignition Capsules

Science.gov (United States)

Cheng, Baolian; Kwan, Thomas J. T.; Wang, Yi-Ming; Yi, S. Austin; Batha, Steve

2017-10-01

Implosion symmetry plays a critical role in achieving high areal density and internal energy at stagnation during hot spot formation in ICF capsules. Asymmetry causes hot spot irregularity and stagnation de-synchronization that results in lower temperatures and areal densities of the hot fuel. These degradations significantly affect the alpha heating process in the DT fuel as well as on the thermonuclear performance of the capsules. In this work, we explore the physical factors determining the shape of the hot spot late in the implosion and the effects of shape on Î+/-particle transport. We extend our ignition theory [1-4] to include the hot spot shape and quantify the effects of the implosion asymmetry on both the ignition criterion and capsule performance. We validate our theory with the NIF existing experimental data Our theory shows that the ignition criterion becomes more restrictive with the deformation of the hot spot. Through comparison with the NIF data, we demonstrate that the shape effects on the capsules' performance become more explicit as the self-heating and yield of the capsules increases. The degradation of the thermonuclear burn by the hot spot shape for high yield shots to date can be as high as 20%. Our theory is in good agreement with the NIF data. This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W-7405-ENG-36.

Stability time of a DT-filled cryogenic ICF target in a high vacuum environment

International Nuclear Information System (INIS)

Ebey, P.S.; Hoffer, J.K.

1998-01-01

Following the successful pressure loading with DT of a thin-walled plastic inertial fusion target shell (such as those designed for use at the OMEGA facility at the University of Rochester's Laboratory for Laser Energetics (UR/LLE)), continual care must be taken to safeguard the shell from being exposed to unacceptable pressure differentials across its wall. In particular, once the DT has been condensed into a liquid or solid phase and the outside pressure has been reduced, the target must be maintained below some upper cutoff temperature such that the vapor pressure of the DT is below the bursting pressure for the shell. Through the process of β-decay the DT self-heats, but while the shell is in a high vacuum environment (P much-lt 0.8 Pa (6 mtorr) for the OMEGA layering sphere) there is only a negligible heat loss mechanism. This will cause the temperature to increase. A calculation has been done to estimate the rate of temperature increase of the loaded target under high vacuum conditions. A functional form for calculating the target's temperature increase given its starting temperature is presented. An overall result is that under high vacuum conditions the DT changes from a solid at 10 K to a liquid at 37 K (T c = 39.4 K) in about 19 minutes. This holding time is significantly less if the initial temperature is higher, the initial state is liquid, or the upper allowed temperature is lower. Simplifying assumptions which were made and their impact on interpreting the results of this calculation are discussed

Measurement of loss of DT fusion products using scintillator detectors in TFTR

International Nuclear Information System (INIS)

Darrow, D.S.; Herrmann, H.W.; Johnson, D.W.; Marsala, R.J.; Palladino, R.W.; Zweben, S.J.

1995-03-01

A poloidal array of MeV ion loss probes previously used to measure DD fusion product loss has been upgraded to measure the loss of alpha particles from DT plasmas in TFTR. The following improvements to the system have been made in preparation for the use of tritium in TFTR: (1) relocation of detectors to a neutronshielded enclosure in the basement to reduce neutron-induced background signals; (2) replacement of ZnS:Cu (P31) scintillators in the probes with the Y 3 Al 5 0 12 :Ce(P46) variety to minimize damage and assure linearity at the fluxes anticipated from DT plasmas; and (3) shielding of the fiber optic bundles which carry the fight from the probes to the detectors to reduce neutron- and gamma-induced light within them. In addition to the above preparations, the probes have been absolutely calibrated for alpha particles by using the Van de Graaf accelerator at Los Alamos National Laboratory. Alpha particle losses from DT plasmas have been observed, and losses at the detector 901 below the midplane are consistent with first orbit loss

Low fuel convergence path to ignition on the NIF

Science.gov (United States)

Schmitt, M. J.; Molvig, Kim; Gianakon, T. A.; Woods, C. N.; Krasheninnikova, N. S.; Hsu, S. C.; Schmidt, D. W.; Dodd, E. S.; Zylstra, Alex; Scheiner, B.; McKenty, P.; Campbell, E. M.; Froula, D.; Betti, R.; Michel, T.

2017-10-01

A novel concept for achieving ignition on the NIF is proposed that obviates current issues plaguing single-shell high-convergence capsules. A large directly-driven Be shell is designed to robustly implode two nested internal shells by efficiently converting 1.7MJ of laser energy from a 6 ns, low intensity laser pulse, into a 1 ns dynamic pressure pulse to ignite and burn a central liquid DT core after a fuel convergence of only 9. The short, low intensity laser pulse mitigates LPI allowing more uniform laser drive of the target and eliminates hot e-, preheat and laser zooming issues. Preliminary rad-hydro simulations predict ignition initiation with 90% maximum inner shell velocity, before deceleration Rayleigh-Taylor growth can cause significant pusher shell mix into the compressed DT fuel. The gold inner pusher shell reduces pre-ignition radiation losses from the fuel allowing ignition to occur at 2.5keV. Further 2D simulations show that the short pulse design results in a spatially uniform kinetic drive that is tolerant to variations in laser cone power. A multi-pronged effort, in collaboration with LLE, is progressing to optimize this design for NIF's PDD laser configuration. Work performed under the auspices of the U.S. Dept. of Energy by the Los Alamos National Security, LLC, Los Alamos National Laboratory under contract DE-FG02-051ER54810.

Thermonuclear-driven fast magnetosonic-wave heating in tokamak plasmas

International Nuclear Information System (INIS)

Sutton, W.R. III.

1982-01-01

A thermonuclear driven fast magnetosonic wave instability is investigated in tokamak plasmas for propagation transverse to the external magnetic field at frequencies of several times the alpha particle gyro rate: ω approx. = L Ω/sub α/ = k/sub perpendicular/ v/sub A/, L approx. 4 to 8, k/sub parallel/ << k/sub perpendicular/. The 2-D differential quasi-linear diffusion equation is derived in circular cylindrical, v/sub perpendicular/-v/sub parallel/ geometry. We perform an expansion in the small parameter k/sub parallel/k/sub perpendicucular/ of the quasi-linear diffusion coefficients

Fusion fuel cycle solid radioactive wastes

International Nuclear Information System (INIS)

Gore, B.F.; Kaser, J.D.; Kabele, T.J.

1978-06-01

Eight conceptual deuterium-tritium fueled fusion power plant designs have been analyzed to identify waste sources, materials and quantities. All plant designs include the entire D-T fuel cycle within each plant. Wastes identified include radiation-damaged structural, moderating, and fertile materials; getter materials for removing corrosion products and other impurities from coolants; absorbents for removing tritium from ventilation air; getter materials for tritium recovery from fertile materials; vacuum pump oil and mercury sludge; failed equipment; decontamination wastes; and laundry waste. Radioactivity in these materials results primarily from neutron activation and from tritium contamination. For the designs analyzed annual radwaste volume was estimated to be 150 to 600 m 3 /GWe. This may be compared to 500 to 1300 m 3 /GWe estimated for the LMFBR fuel cycle. Major waste sources are replaced reactor structures and decontamination waste

Cryogenic tritium-hydrogen-deuterium and deuterium-tritium layer implosions with high density carbon ablators in near-vacuum hohlraums

International Nuclear Information System (INIS)

Meezan, N. B.; Hopkins, L. F. Berzak; Pape, S. Le; Divol, L.; MacKinnon, A. J.; Döppner, T.; Ho, D. D.; Jones, O. S.; Khan, S. F.; Ma, T.; Milovich, J. L.; Pak, A. E.; Ross, J. S.; Thomas, C. A.; Benedetti, L. R.; Bradley, D. K.; Celliers, P. M.; Clark, D. S.; Field, J. E.; Haan, S. W.

2015-01-01

High Density Carbon (or diamond) is a promising ablator material for use in near-vacuum hohlraums, as its high density allows for ignition designs with laser pulse durations of <10 ns. A series of Inertial Confinement Fusion (ICF) experiments in 2013 on the National Ignition Facility [Moses et al., Phys. Plasmas 16, 041006 (2009)] culminated in a deuterium-tritium (DT) layered implosion driven by a 6.8 ns, 2-shock laser pulse. This paper describes these experiments and comparisons with ICF design code simulations. Backlit radiography of a tritium-hydrogen-deuterium (THD) layered capsule demonstrated an ablator implosion velocity of 385 km/s with a slightly oblate hot spot shape. Other diagnostics suggested an asymmetric compressed fuel layer. A streak camera-based hot spot self-emission diagnostic (SPIDER) showed a double-peaked history of the capsule self-emission. Simulations suggest that this is a signature of low quality hot spot formation. Changes to the laser pulse and pointing for a subsequent DT implosion resulted in a higher temperature, prolate hot spot and a thermonuclear yield of 1.8 × 10 15 neutrons, 40% of the 1D simulated yield

Cryogenic tritium-hydrogen-deuterium and deuterium-tritium layer implosions with high density carbon ablators in near-vacuum hohlraums

Energy Technology Data Exchange (ETDEWEB)

Meezan, N. B., E-mail: meezan1@llnl.gov; Hopkins, L. F. Berzak; Pape, S. Le; Divol, L.; MacKinnon, A. J.; Döppner, T.; Ho, D. D.; Jones, O. S.; Khan, S. F.; Ma, T.; Milovich, J. L.; Pak, A. E.; Ross, J. S.; Thomas, C. A.; Benedetti, L. R.; Bradley, D. K.; Celliers, P. M.; Clark, D. S.; Field, J. E.; Haan, S. W. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551-0808 (United States); and others

2015-06-15

High Density Carbon (or diamond) is a promising ablator material for use in near-vacuum hohlraums, as its high density allows for ignition designs with laser pulse durations of <10 ns. A series of Inertial Confinement Fusion (ICF) experiments in 2013 on the National Ignition Facility [Moses et al., Phys. Plasmas 16, 041006 (2009)] culminated in a deuterium-tritium (DT) layered implosion driven by a 6.8 ns, 2-shock laser pulse. This paper describes these experiments and comparisons with ICF design code simulations. Backlit radiography of a tritium-hydrogen-deuterium (THD) layered capsule demonstrated an ablator implosion velocity of 385 km/s with a slightly oblate hot spot shape. Other diagnostics suggested an asymmetric compressed fuel layer. A streak camera-based hot spot self-emission diagnostic (SPIDER) showed a double-peaked history of the capsule self-emission. Simulations suggest that this is a signature of low quality hot spot formation. Changes to the laser pulse and pointing for a subsequent DT implosion resulted in a higher temperature, prolate hot spot and a thermonuclear yield of 1.8 × 10{sup 15} neutrons, 40% of the 1D simulated yield.

Prospects for Tokamak Fusion Reactors

International Nuclear Information System (INIS)

Sheffield, J.; Galambos, J.

1995-01-01

This paper first reviews briefly the status and plans for research in magnetic fusion energy and discusses the prospects for the tokamak magnetic configuration to be the basis for a fusion power plant. Good progress has been made in achieving fusion reactor-level, deuterium-tritium (D-T) plasmas with the production of significant fusion power in the Joint European Torus (up to 2 MW) and the Tokamak Fusion Test Reactor (up to 10 MW) tokamaks. Advances on the technologies of heating, fueling, diagnostics, and materials supported these achievements. The successes have led to the initiation of the design phases of two tokamaks, the International Thermonuclear Experimental Reactor (ITER) and the US Toroidal Physics Experiment (TPX). ITER will demonstrate the controlled ignition and extended bum of D-T plasmas with steady state as an ultimate goal. ITER will further demonstrate technologies essential to a power plant in an integrated system and perform integrated testing of the high heat flux and nuclear components required to use fusion energy for practical purposes. TPX will complement ITER by testing advanced modes of steady-state plasma operation that, coupled with the developments in ITER, will lead to an optimized demonstration power plant

Role of thermonuclear instability in recent models of nova stars

Energy Technology Data Exchange (ETDEWEB)

Secco, L [Padua Univ. (Italy). Ist. di Astronomia

1981-10-11

In this paper we review models of nova-star explosion based on the original suggestion by Kraft and developed during about ten years (from 1967). We aim at summarizing here the most salient results of those theoretical models and to point out the many aspects of the problems that are still unsettled. In particular, we analyse thermonuclear instabilities both in perfect and electron-degenerate gas, since they seem to be at the base of the nova explosion phenomena.

Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

Science.gov (United States)

Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; Olson, R. E.; Cobble, J. A.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Parra-Vasquez, N. A. G.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

2016-05-01

Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Work is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. The ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.

MUON DETECTORS: DT

CERN Multimedia

Marco Dallavalle

2012-01-01

  Although the year 2012 is the third year without access to the chambers and the Front-End electronics, the fraction of good channels is still very high at 99.1% thanks also to the constant care provided by the on-site operation team. The downtime caused to CMS as a consequence of DT failures is to-date <2%. The intervention on the LV power supplies, which required a large number of CAEN modules (137 A3050, 13 A3100, and 3 MAO) to be removed from the detector, reworked and tested during this Year-End Technical Stop, can now, after a few months of stable operation of the LV, be declared to have solved once-and-for-all the persistent problem with the overheating LV Anderson connectors. Another piece of very good news is that measurements of the noise from single-hit rate outside the drift-time box as a function of the LHC luminosity show that the noise rate and distribution are consistent with expectations of the simulations in the Muon TDR, which have guided the detector design and constru...

MUON DETECTORS: DT

CERN Multimedia

C. Fernandez Bedoya

2011-01-01

The DT system has behaved highly satisfactorily throughout the LHC 2010 data-taking period, with more than 99% of the system operational and very few downtime periods. This includes operation with heavy ions collisions in which the rate of muons was low and no impact was observed in the buffer occupancies. An unexpected out-of-time high occupancy was observed in the outermost chambers (MB4) and its origin is under investigation. During the winter technical shutdown many interventions took place with the main goal of optimising the system. One of the main improvements is in the slow control mechanism through the DTTF boards: the problem that was preventing us from monitoring the OptoRX modules properly has been fixed satisfactorily. Other main changes include the installation of a new VME PCI controller to minimise the downtime in case of crate power cycle and the reduction from 10 to the design 5 FEDs, that became possible thanks to the good agreement of the event size with our expectations during LHC operat...

MUON DETECTORS: DT

CERN Multimedia

A. Benvenuti

The DT maintenance work that started in November is completed. All interventions have been successful: the total fraction of cells that are disconnected from the HV is back to the 0.2% inherited from construction and installation. Work on YB0 was not as difficult as anticipated. A basic requirement was to carefully plan and to setup the storage space for the EB LV cables. The cables were removed and reinstalled by the TC teams. It was a delicate operation that required a specific solution in each position. Special platforms, designed by Domenico Dattola, were used for stepping on the vacuum tank without removing the thermal screens. They worked very well for the maintenance of minicrates and to access the HO readout boxes in the top sectors of YB-1. For future interventions, the major worry is to intervene on the top sectors (S03, S04, S05) especially on YB+/-2, since heavy work must be done above the beam pipe. Massimo Benettoni is working on a sturdy protection to be anchored on the vacuum tank and the MB1...

MUON DETECTORS: DT

CERN Multimedia

C. Fernandez Bedoya

2012-01-01

  The major activity of the DT group during this Year-End Technical Stop has been the reworking of LV modules. It has been a large campaign, carefully planned, to try to solve, once and for all, the long-standing problem of Anderson Power connectors overheating. The solution involved removing the 140 CAEN modules from the detector (6.5 kg each), soldering of “pigtails” in a temporary workshop in USC, and thorough testing of all the modules in a local system installed in USC. The operation has been satisfactorily smooth, taking into account the magnitude of the intervention. The system is now back in good shape and ready for commissioning. In addition, HV boards have been cleaned up, HV USC racks have been equipped with water detection cables, and the gas and HV have been switched back on smoothly. Other significant activities have also taken place during this YETS, such as the installation of a new and faster board for the Minicrates secondary link and the migration to Scienti...

Baking method for thermonuclear reactor

International Nuclear Information System (INIS)

Kobayashi, Shigetada.

1986-01-01

Purpose: To improve the heat transmission property to the reactor core structures thereby shortening the baking time for the reactor core in thermonuclear reactors. Constitution: High temperature airs are supplied from a baking system to cooling pipeways disposed within reactor core structures and helium gas is supplied from a helium gas supply system through the reactor core structures to the inside of the reactor core for scavenging. The scavenging operation may be combined with vacuum suction. Further, the inside of the reactor is scavenged while maintaining at such a negative pressure as within a range not degrading the heat conduction property. Since the helium gas is chemically inert and poor in the depositing property, it shows no adsorbability even for the material heated to high temperature. Further, since the diffusion and heat conduction properties are high, the heat conduction property to the materials upon baking can be improved to shorten the baking time. No disadvantages are caused by the introduction of the helium gas upon baking. (Kawakami, Y.)

Fast ignition upon the implosion of a thin shell onto a precompressed deuterium-tritium ball

Science.gov (United States)

Gus'kov, S. Yu.; Zmitrenko, N. V.

2012-11-01

Fast ignition of a precompressed inertial confinement fusion (ICF) target by a hydrodynamic material flux is investigated. A model system of hydrodynamic objects consisting of a central deuterium-tritium (DT) ball and a concentric two-layer shell separated by a vacuum gap is analyzed. The outer layer of the shell is an ablator, while the inner layer consists of DT ice. The igniting hydrodynamic flux forms as a result of laser-driven acceleration and compression of the shell toward the system center. A series of one-dimensional numerical simulations of the shell implosion, the collision of the shell with the DT ball, and the generation and propagation of thermonuclear burn waves in both parts of the system are performed. Analytic models are developed that describe the implosion of a thin shell onto a central homogeneous ball of arbitrary radius and density and the initiation and propagation of a thermonuclear burn wave induced by such an implosion. Application of the solution of a model problem to analyzing the implosion of a segment of a spherical shell in a conical channel indicates the possibility of fast ignition of a spherical ICF target from a conical target driven by a laser pulse with an energy of 500-700 kJ.

Vacuum problems of thermonuclear reactor design

International Nuclear Information System (INIS)

Paty, L.

1981-01-01

A thermonuclear reactor can be considered to be a vacuum system in which constant concentration should be maintained of reacting particles while permanently discharging the undesirable particles using a system of pumps. The discharging proceeds in two stages: in the former, the reactor is degassed using external pumps connected to the reactor chamber through a pumping pipe. The latter in which hydrogen is admitted, uses high pump-rate machines based on the principle of the binding of the gas to the pump surface and must not introduce molecules of higher atomic mass in the system. Turbomolecular pumps of diffusion oil pumps are most suitable for the former stage while condensation, cryosorption, titanium pumping machines and special pumping methods are most suitable for the latter stage. Examples are shown of the pump system design for Tokamak 10 and for facilities at the Euratom laboratory in Fontenay-aux-Roses. (M.D.)

Baking exhaustion device in thermonuclear device

Energy Technology Data Exchange (ETDEWEB)

Kondo, Mitsunori.

1987-02-02

Purpose: To rapidly remove tritium and impurity from the vacuum region in the access port of the baking exhaustion device in a thermonuclear device. Constitution: Each of the gaps at the boundary between a fixed shielding member and a blanket module and at the boundary between the blanket and a divertor is made extremely small so as to minimize the neutron streaming from plasmas. Accordingly, in the case of evacuating the vacuum region in the access port, the gap conductance is extremely poor and the exhaustion speed is low. Then, baking pipeways for flowing high temperature fluids are embedded to the surface layer at the position facing to the vacuum region and the plasma evacuation duct and the vacuum region are connected with an evacuation duct of the access port. By flowing high temperature fluids in the pipeways and conducting evacuation, baking exhaustion can be carried out rapidly. (Kamimura, M.).

Reprocessing of nuclear fuels at the Savannah River Plant

International Nuclear Information System (INIS)

Gray, L.W.

1986-01-01

For more than 30 years, the Savannah River Plant (SRP) has been a major supplier of nuclear materials such as plutonium-239 and tritium-3 for nuclear and thermonuclear weapons, plutonium-238 for space exploration, and isotopes of americium, curium, and californium for use in the nuclear research community. SRP is a complete nuclear park, providing most of the processes in the nuclear fuel cycle. Key processes involve fabrication and cladding of the nuclear fuel, target, and control assemblies; rework of heavy water for use as reactor moderator; reactor loading, operation, and unloading; chemical recovery of the reactor transmutation products and spent fuels; and management of the gaseous, liquid, and solid nuclear and chemical wastes; plus a host of support operations. The site's history and the key processes from fabrication of reactor fuels and targets to finishing of virgin plutonium for use in the nuclear weapons complex are reviewed. Emphasis has been given to the chemistry of the recovery and purification of weapons grade plutonium from irradiated reactor targets

Role of thermonuclear instabilities of recent models of nova-stars

Energy Technology Data Exchange (ETDEWEB)

Secco, L [Padua Univ. (Italy). Ist. di Astronomia

1981-10-11

In this paper, a review models of nova-star explosion based on the original suggestion by Kraft and developed during about ten years (from 1967) is presented. The aim is to summarize the most salient results of those theoretical models and to point out the many aspects of the problems that are still unsettled. In particular, thermonuclear instabilities both in perfect and electron-degenerate gas are analyzed, since they seem to be at the base of the nova explosion phenomena.

Effect of logarithmic terms on the energy level and wave function of a dtμ system

International Nuclear Information System (INIS)

Zhen, Z.

1990-01-01

The effect of the logarithmic terms on the ground-state energy level and wave function of a dtμ system is investigated. No significant contribution of the logarithmic terms on either the energy level or wave function is found. At the same time, we find the lowest upper bound of the ground-state energy ever obtained by the variational method using the Hylleraas-type trial function and that the corresponding wave function satisfies the cusp condition as r dt →0 automatically to a reasonable accuracy for r<3 (muonic a.u.), where r is the distance between the fused dt nuclear compound and the muon

Physics of thermo-nuclear fusion and the ITER project; La physique de la fusion thermonucleaire et le projet ITER

Energy Technology Data Exchange (ETDEWEB)

Garin, P [CEA Cadarache, Dept. de Recherches sur la Fusion Controlee - DRFC, 13 - Saint-Paul-lez-Durance (France)

2003-01-01

This document gathers the slides of the 6 contributions to the workshop 'the physics of thermo-nuclear fusion and the ITER project': 1) the feasibility of magnetic confinement and the issue of heat recovery, 2) heating and current generation in tokamaks, 3) the physics of wall-plasma interaction, 4) recent results at JET, 5) inertial confinement and fast ignition, and 6) the technology of fusion machines based on magnetic confinement. This document presents the principles of thermo-nuclear fusion machines and gives a lot of technical information about JET, Tore-Supra and ITER.

First measurements of dtμ-cycle characteristics in liquid H/D/T mixture

International Nuclear Information System (INIS)

Averin, Yu.P.; Balin, D.V.; Bom, V.R.

1998-01-01

The muon catalyzed fusion in dense triple mixture of hydrogen isotopes has been investigated for the first time. The experimental method is based on the registration of neutrons from dtμ fusions by a full absorption detectors in 4π geometry. The measurements have been performed in H/D/T mixture at T = 22 K and φ ≅ 1.1 LHD at four sets of isotope concentrations. The basic parameters of dtμ cycle (neutron yield, cycling rate and total sticking) in H/D/T mixtures are presented and discussed

QA support for TFTR reliability improvement program in preparation for DT operation

International Nuclear Information System (INIS)

Parsells, R.F.; Howard, H.P.

1987-01-01

As TFTR approaches experiments in the Q=1 regime, machine reliability becomes a major variable in achieving experimental objectives. This paper describes the methods used to quantify current reliability levels, levels required for D-T operations, proposed methods for reliability growth and improvement, and tracking of reliability performance in that growth. Included in this scope are data collection techniques and short comings, bounding current reliability on the upper end, and requirements for D-T operations. Problem characterization through Pareto diagrams provides insight into recurrent failure modes and the use of Duane plots for charting of reliability changes both cumulative and instantaneous, is explained and demonstrated

Measurements of DT alpha particle loss near the outer midplane of TFTR

International Nuclear Information System (INIS)

Zweben, S.J.; Darrow, D.S.; Herrmann, H.W.; Redi, M.H.; Schivell, J.; White, R.B.

1995-07-01

Measurements of DT alpha particle loss to the outer midplane region of TFTR have been made using a radially movable scintillator detector. The conclusion from this data is that mechanisms determining the DT alpha loss to the outer midplane are not substantially different from those for DD fusion products. Some of these results are compared with a simplified theoretical model for TF ripple-induced alpha loss, which is expected to be the dominant classical alpha loss mechanism near the outer midplane. An example of plasma-driven MHD-induced alpha particle loss is shown, but no signs of any ''collective'' alpha instability-induced alpha loss have yet been observed

Thermonuclear reactor materials composed of glassy carbons

International Nuclear Information System (INIS)

Kazumata, Yukio.

1979-01-01

Purpose: To improve the durability to plasma radiation by the use of glassy carbon as the structural materials for the first wall and the blanket in thermonuclear devices. Constitution: The glassy carbon (glass-like carbon) is obtained by forming specific organic substances into a predetermined configuration and carbonizing them by heat decomposition under special conditions. They are impermeable carbon material of 1.40 - 1.70 specific gravity, less graphitizable and being almost in isotropic crystal forms in which isotropic structure such as in graphite is scarcely observed. They have an extremely high hardness, are less likely to be damaged when exposed to radiation and have great strength and corrosion resistance. Accordingly, the service life of the reactor walls and the likes can remarkably be increased by using the materials. (Horiuchi, T.)

Integration of element technology and system supporting thermonuclear fusion

International Nuclear Information System (INIS)

2003-01-01

A special committee for integrated system technology survey on thermonuclear fusion (TNF) was begun on June, 1999, under an aim to generally summarize whole of shapes on technology to realize TNF reactor to summarize present state of every technologies and their positioning in whole of their TNF technology. On a base of survey of these recent informations, this report is comprehensively summarized for an integrated system technology on TNF. It has outlines on magnetic field enclosing method, outlines on inertia enclosing method, element technology supporting TNF, new power generation techniques, and ripple effects on TNF technology. (G.K.)

Approximating the r-process on earth with thermonuclear explosions

International Nuclear Information System (INIS)

Becker, S.A.

1992-01-01

The astrophysical r-process can be approximately simulated in certain types of thermonuclear explosions. Between 1952 and 1969 twenty-three nuclear tests were fielded by the United States which had as one of their objectives the production of heavy transuranic elements. Of these tests, fifteen were at least partially successful. Some of these shots were conducted under the project Plowshare Peaceful Nuclear Explosion Program as scientific research experiments. A review of the program, target nuclei used, and heavy element yields achieved, will be presented as well as discussion of plans for a new experiment in a future nuclear test

Evidence for a link between atmospheric thermonuclear detonations and nitric acid

International Nuclear Information System (INIS)

Holdsworth, G.

1986-01-01

Data are presented for an ice core, which show that during the era of intense atmospheric thermonuclear weapons testing, a significant part of the nitrate content in the snow was modulated by the intensity of the nuclear detonations. The fixation of nitrogen by nuclear fireballs leads to NOsub(x) gases in the atmosphere and ultimately to nitric acid in precipitation. At certain concentrations, these gases and the associated aerosols may perturb the climate. (author)

ON THE PROGENITOR SYSTEM OF THE TYPE Iax SUPERNOVA 2014dt IN M61

Energy Technology Data Exchange (ETDEWEB)

Foley, Ryan J. [Astronomy Department, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States); Van Dyk, Schuyler D. [IPAC/Caltech, Mail Code 100-22, Pasadena, CA 91125 (United States); Jha, Saurabh W. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Clubb, Kelsey I.; Filippenko, Alexei V.; Mauerhan, Jon C. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Miller, Adam A. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 169-506, Pasadena, CA 91109 (United States); Smith, Nathan [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)

2015-01-10

We present pre-explosion and post-explosion Hubble Space Telescope images of the Type Iax supernova (SN Iax) 2014dt in M61. After astrometrically aligning these images, we do not detect any stellar sources at the position of the SN in the pre-explosion images to relatively deep limits (3σ limits of M {sub F438W} > –5.0 mag and M {sub F814W} > –5.9 mag). These limits are similar to the luminosity of SN 2012Z's progenitor system (M {sub F435W} = –5.43 ± 0.15 and M {sub F814W} = –5.24 ± 0.16 mag), the only probable detected progenitor system in pre-explosion images of a SN Iax, and indeed, of any white-dwarf supernova. SN 2014dt is consistent with having a C/O white-dwarf primary/helium-star companion progenitor system, as was suggested for SN 2012Z, although perhaps with a slightly smaller or hotter donor. The data are also consistent with SN 2014dt having a low-mass red giant or main-sequence star companion. The data rule out main-sequence stars with M {sub init} ≳ 16 M {sub ☉} and most evolved stars with M {sub init} ≳ 8 M {sub ☉} as being the progenitor of SN 2014dt. Hot Wolf-Rayet stars are also allowed, but the lack of nearby bright sources makes this scenario unlikely. Because of its proximity (D = 12 Mpc), SN 2014dt is ideal for long-term monitoring, where images in ∼2 yr may detect the companion star or the luminous bound remnant of the progenitor white dwarf.

Chemically ignited thermonuclear reactions: A near-term means for a high specific impulse - High thrust propulsion system

International Nuclear Information System (INIS)

Winterberg, F.

1982-01-01

A proposal for the fissionless ignition of small thermonuclear reactions is made which involves the combination of the magnetic booster target inertial fusion concept with the chemical implosion of metallic shells. The magnetic booster employs a very dense and magnetically confined low yield thermonuclear plasma to trigger an inertially confined high yield plasma. Fissionless ignition permits smaller yields than with fission- or fusion-induced fusion bombs, yields that are appropriate for use in a spacecraft propulsion system. Each bomb would release about 10 to the 18th erg or 100 tons of TNT, and with one explosion per second, an average thrust of 10 to the third tons and a specific impulse of about 3000 seconds can be expected

First fusion neutrons from a thermonuclear weapon device

International Nuclear Information System (INIS)

Anon.

1976-01-01

An account of the first observation of thermonuclear neutrons from a hydrogen weapon, the George shot, is presented. A personal narrative by the researchers J. Allred and L. Rosen includes such topics as the formation of the experimental team, description of the experimental technique, testing the experimental apparatus, testing the effects of a blast, a description of the test area, and the observation of neutrons from fusion. Excerpts are presented from several chapters of the Scientific Director's report on the atomic weapons tests of 1951. Also included is a brief description of the basic design of the hydrogen bomb, a recounting of subsequent developments, and short scientific biographies of the researchers. 21 figures, 2 tables

Monte Carlo Simulation on Compensated Neutron Porosity Logging in LWD With D-T Pulsed Neutron Generator

International Nuclear Information System (INIS)

Zhang Feng; Hou Shuang; Jin Xiuyun

2010-01-01

The process of neutron interaction induced by D-T pulsed neutron generator and 241 Am-Be source was simulated by using Monte Carlo method. It is concluded that the thermal neutron count descend exponentially as the spacing increasing. The smaller porosity was, the smaller the differences between the two sources were. When the porosity reached 40%, the ratio of thermal neutron count generated by D-T pulsed neutron source was much larger than that generated by 241 Am-Be neutron source, and its distribution range was wider. The near spacing selected was 20-30 cm, and that of far spacing was about 60-70 cm. The detection depth by using D-T pulsed neutron source was almost unchanged under condition of the same sapcing, and the sensitivity of measurement to the formation porosity decreases. The results showed that it can not only guarantee the statistic of count, but also improve detection sensitivity and depth at the same time of increasing spacing. Therefore, 241 Am-Be neutron source can be replaced by D-T neutron tube in LWD tool. (authors)

High-energy, twelve-channel laser facility (DEFIN) for spherical irradiation of thermonuclear targets

International Nuclear Information System (INIS)

Basov, N.G.; Danilov, A.E.; Krokhin, O.N.; Kruglov, B.V.; Mikhailov, Yu.A.; Sklizkov, G.V.; Fedotov, S.I.; Fedorov, A.N.

This paper describes a high-energy, twelve-channel laser facility (DELFIN) intended for high-temperature heating of thermonuclear targets with spherical symmetry. The facility includes a neodymium-glass laser with the ultimate radiation energy of 10 kJ, a pulse length of approximately 10 -10 to 10 -9 s, beam divergence of 5 x 10 -4 radians, a vacuum chamber in which laser radiation interacts with the plasma, and a system of diagnostic instrumentation for the observation of laser beam and plasma parameters. Described are the optical scheme and construction details of the laser facility. Presented is an analysis of focusing schemes for target irradiation and described is the focusing scheme of the DELFIN facility, which is capable of attaining a high degree of spherical symmetry in irradiating targets with maximum beam intensity at the target surface of approximately 10 15 W/cm 2 . This paper examines the most important problems connected with the physical investigations of thermonuclear laser plasma and the basic diagnostic problems involved in their solution

Protection device for a thermonuclear device

International Nuclear Information System (INIS)

Kawashima, Shuichi.

1986-01-01

Purpose: To exactly detect the void coefficients of coolants even under high magnetic fields thereby detect the overheat of a thermonuclear device at an early stage. Constitution: The protecting device of this invention comprises a laser beam generation device, a laser beam detection device and an accident detection device. The laser generation device always generates laser beams, which are permeated through coolants and detected by the laser beam detection device, the optical amount of which is transmitted to the accident detection device. The accident detection device judges the excess or insufficiency of the detected optical amount with respect to the optical amount of the laser beams under the stationary state as a reference and issues an accident signal. Since only the optical cables that do not undergo the effect of the magnetic fields are exposed to high magnetic fields in the protection device of this invention, a high reliability can be maintained. (Kamimura, M.)

CFTSIM-ITER dynamic fuel cycle model

International Nuclear Information System (INIS)

Busigin, A.; Gierszewski, P.

1998-01-01

Dynamic system models have been developed for specific tritium systems with considerable detail and for integrated fuel cycles with lesser detail (e.g. D. Holland, B. Merrill, Analysis of tritium migration and deposition in fusion reactor systems, Proceedings of the Ninth Symposium Eng. Problems of Fusion Research (1981); M.A. Abdou, E. Vold, C. Gung, M. Youssef, K. Shin, DT fuel self-sufficiency in fusion reactors, Fusion Technol. (1986); G. Spannagel, P. Gierszewski, Dynamic tritium inventory of a NET/ITER fuel cycle with lithium salt solution blanket, Fusion Eng. Des. (1991); W. Kuan, M.A. Abdou, R.S. Willms, Dynamic simulation of a proposed ITER tritium processing system, Fusion Technol. (1995)). In order to provide a tool to understand and optimize the behavior of the ITER fuel cycle, a dynamic fuel cycle model called CFTSIM is under development. The CFTSIM code incorporates more detailed ITER models, specifically for the important isotope separation system, and also has an easier-to-use graphical interface. This paper provides an overview of CFTSIM Version 1.0. The models included are those with significant and varying tritium inventories over a test campaign: fueling, plasma and first wall, pumping, fuel cleanup, isotope separation and storage. An illustration of the results is shown. (orig.)

Numerical simulation of performance of heavy ion inertial confinement fusion target with ellipsoidal chamber

International Nuclear Information System (INIS)

Basin, A.A.; Vatulin, V.V.; Vakhlamova, L.L.; Vinokurov, P.A.; Dement'ev, Yu.A.; Eliseev, G.M.; Ermolovich, V.F.; Morenko, L.Z.; Morenko, A.I.; Remizov, G.N.; Romanov, Yu.A.; Ryabikina, N.A.; Skrypnik, S.I.; Skidan, G.I.; Tikhomirov, B.P.; Shagaliev, R.M.

1996-01-01

To solve the design problem of an inertial thermonuclear fusion facility requires the united efforts of scientists in various countries. In the field of heavy ion fusion a collaboration between scientists in Germany and Russia is under successful development. VNIIEF possesses advanced software for numerical simulation of the processes in thermonuclear target operation. This paper describes a target design suggested and being studied by scientists of Frankfurt University and GSI which is based on 2D non-stationary calculation of the X-ray energy transport and capsule compression. The target consists of a spherical capsule with DT fuel and an ellipsoidal chamber containment. The ion beam energy is released in two fixed converters located on the chamber axis symmetricall with respect to the capsule. The X-ray field is formed on the capsule surface with a set of special shields. The basic aim of our research is to estimate the effect of gas dynamic expansion of the chamber walls, shields and capsule on the target operation. To increase the reliability of the obtained results and the assessment of probable errors in predicting radiation field parameters and the capsule state, the calculations were accomplished in a kinetic arrangement with various techniques. (orig.)

Complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

CERN Document Server

Bilski, P; D'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

2006-01-01

This report outlines the research needs and research activities within Europe to develop new and improved methods and techniques for the characterization of complex radiation fields at workplaces around high-energy accelerators and the next generation of thermonuclear fusion facilities under the auspices of the COordinated Network for RAdiation Dosimetry (CONRAD) project funded by the European Commission.

Transient temperature variations during the self-heating of a plasma by thermonuclear reactions

Energy Technology Data Exchange (ETDEWEB)

Greyber, Howard D [University of California Radiation Laboratory, Livermore, CA (United States)

1958-07-01

The motivation for this work arose from an observation by Rosenbluth that in a different but related physical situation, the electron temperature) could exceed ion temperature, during transient heating. We have undertaken to trace the transient temperatures to be expected in an idealized physical situation that still bears some resemblance to what one envisions for the Controlled Thermonuclear Reactor.

Reducing disk storage of full-3D seismic waveform tomography (F3DT) through lossy online compression

Science.gov (United States)

Lindstrom, Peter; Chen, Po; Lee, En-Jui

2016-08-01

Full-3D seismic waveform tomography (F3DT) is the latest seismic tomography technique that can assimilate broadband, multi-component seismic waveform observations into high-resolution 3D subsurface seismic structure models. The main drawback in the current F3DT implementation, in particular the scattering-integral implementation (F3DT-SI), is the high disk storage cost and the associated I/O overhead of archiving the 4D space-time wavefields of the receiver- or source-side strain tensors. The strain tensor fields are needed for computing the data sensitivity kernels, which are used for constructing the Jacobian matrix in the Gauss-Newton optimization algorithm. In this study, we have successfully integrated a lossy compression algorithm into our F3DT-SI workflow to significantly reduce the disk space for storing the strain tensor fields. The compressor supports a user-specified tolerance for bounding the error, and can be integrated into our finite-difference wave-propagation simulation code used for computing the strain fields. The decompressor can be integrated into the kernel calculation code that reads the strain fields from the disk and compute the data sensitivity kernels. During the wave-propagation simulations, we compress the strain fields before writing them to the disk. To compute the data sensitivity kernels, we read the compressed strain fields from the disk and decompress them before using them in kernel calculations. Experiments using a realistic dataset in our California statewide F3DT project have shown that we can reduce the strain-field disk storage by at least an order of magnitude with acceptable loss, and also improve the overall I/O performance of the entire F3DT-SI workflow significantly. The integration of the lossy online compressor may potentially open up the possibilities of the wide adoption of F3DT-SI in routine seismic tomography practices in the near future.

Comparison of preliminary D-T and ''catalyzed'' D-D system studies

International Nuclear Information System (INIS)

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

1976-01-01

The purpose of the research currently underway is to provide technological and eventual economic comparison of a reference D-T reactor to a ''catalyzed'' D-D reactor. Two separate reactor designs are delineated and examined for this purpose. These systems include plasma parameters, blanket and shield configurations, magnetic coil configurations, and power conversion systems, including a divertor-direct convertor system for the D-D design. The initial conclusions reached are as follows: (a) no extraordinary requirements in the D-D reactor in the areas of blanket or magnet technology, (b) advantageous use of minimum activity blankets and shields, (c) increased overall efficiency via introduction of divertor-direct convertor subsystem in D-D design and (d) 65 percent increase in the toroidal radius of the D-D design compared to the D-T reference value

`elyon as hypostasis of Ahura Mazda – a reading of Dt 32.8-9

Directory of Open Access Journals (Sweden)

Osvaldo Luiz Ribeiro

2016-12-01

Full Text Available The paper postulates the hypothesis of reading of Dt 32.8-9 as monolatrous and post-exilic narrative, written in context of political and cultural subordination to the Persian hegemony, whose Empire depends relentlessly on the restoration and preservation of Judah. Dt 32,1-43 would answer for the sui generis characterization of the theology of the text that, despite the monolatrous theology embodied in the passage and the expressed horror at the idea of the nation of Yahweh to worship other gods. The textual composition is compelled to assume the thesis that Yahweh's exclusive ownership of Judahis due to the determination of `elyôn, which is then interpreted, as the hypostasis of Ahura Mazda and that, in geopolitical terms, embodies the very Persian Empire. It is assumed therefore that Dt 32.8-9 is a political-theological passage of legitimation of Judahite political-theological system in the light of the Persian geopolitical system.

Effects of DD and DT neutron irradiation on some Si devices for fusion diagnostics

International Nuclear Information System (INIS)

Tanimura, Y.; Iida, T.

1998-01-01

In order to examine the difference in the irradiation effects on Si devices between DT and DD neutrons, CCD image sensors, memory ICs and a Si detector were irradiated with neutrons from a deuteron accelerator. The transient effects (i.e. neutron-induced background noises) and permanent effects (i.e. neutron damage) on them were in situ measured during irradiation. Regarding the transient effects, brightening spot noises, soft-error upsets and induced-charge noises were measured for the CCDs, memory ICs and Si detector, respectively. As for the permanent effect, the number of damaged cells of the CCDs and the leakage current of the Si detector increased with neutron fluence. Also we developed a Monte-Carlo code with the TRIM code to evaluate the correlation of DT and DD neutron effects on Si devices. The calculated correlation factor of DT and DD neutron damage for Si devices agreed approximately with the correlation factor obtained from the irradiation experiments on the CCDs and Si detector. (orig.)

Effects of DD and DT neutron irradiation on some Si devices for fusion diagnostics

Science.gov (United States)

Tanimura, Yoshihiko; Iida, Toshiyuki

1998-10-01

In order to examine the difference in the irradiation effects on Si devices between DT and DD neutrons, CCD image sensors, memory ICs and a Si detector were irradiated with neutrons from a deuteron accelerator. The transient effects (i.e. neutron-induced background noises) and permanent effects (i.e. neutron damage) on them were in situ measured during irradiation. Regarding the transient effects, brightening spot noises, soft-error upsets and induced-charge noises were measured for the CCDs, memory ICs and Si detector, respectively. As for the permanent effect, the number of damaged cells of the CCDs and the leakage current of the Si detector increased with neutron fluence. Also we developed a Monte-Carlo code with the TRIM code to evaluate the correlation of DT and DD neutron effects on Si devices. The calculated correlation factor of DT and DD neutron damage for Si devices agreed approximately with the correlation factor obtained from the irradiation experiments on the CCDs and Si detector.

Optimization of the fission--fusion hybrid concept

International Nuclear Information System (INIS)

Saltmarsh, M.J.; Grimes, W.R.; Santoro, R.T.

1979-04-01

One of the potentially attractive applications of controlled thermonuclear fusion is the fission--fusion hybrid concept. In this report we examine the possible role of the hybrid as a fissile fuel producer. We parameterize the advantages of the concept in terms of the performance of the fusion device and the breeding blanket and discuss some of the more troublesome features of existing design studies. The analysis suggests that hybrids based on deuterium--tritium (D--T) fusion devices are unlikely to be economically attractive and that they present formidable blanket technology problems. We suggest an alternative approach based on a semicatalyzed deuterium--deuterium (D--D) fusion reactor and a molten salt blanket. This concept is shown to emphasize the desirable features of the hybrid, to have considerably greater economic potential, and to mitigate many of the disadvantages of D--T-based systems

THE FERMI-GBM X-RAY BURST MONITOR: THERMONUCLEAR BURSTS FROM 4U 0614+09

International Nuclear Information System (INIS)

Linares, M.; Chakrabarty, D.; Connaughton, V.; Bhat, P. N.; Briggs, M. S.; Preece, R.; Jenke, P.; Kouveliotou, C.; Wilson-Hodge, C. A.; Van der Horst, A. J.; Camero-Arranz, A.; Finger, M.; Paciesas, W. S.; Beklen, E.; Von Kienlin, A.

2012-01-01

Thermonuclear bursts from slowly accreting neutron stars (NSs) have proven difficult to detect, yet they are potential probes of the thermal properties of the NS interior. During the first year of a systematic all-sky search for X-ray bursts using the Gamma-ray Burst Monitor aboard the Fermi Gamma-ray Space Telescope we have detected 15 thermonuclear bursts from the NS low-mass X-ray binary 4U 0614+09 when it was accreting at nearly 1% of the Eddington limit. We measured an average burst recurrence time of 12 ± 3 days (68% confidence interval) between 2010 March and 2011 March, classified all bursts as normal duration bursts and placed a lower limit on the recurrence time of long/intermediate bursts of 62 days (95% confidence level). We discuss how observations of thermonuclear bursts in the hard X-ray band compare to pointed soft X-ray observations and quantify such bandpass effects on measurements of burst radiated energy and duration. We put our results for 4U 0614+09 in the context of other bursters and briefly discuss the constraints on ignition models. Interestingly, we find that the burst energies in 4U 0614+09 are on average between those of normal duration bursts and those measured in long/intermediate bursts. Such a continuous distribution in burst energy provides a new observational link between normal and long/intermediate bursts. We suggest that the apparent bimodal distribution that defined normal and long/intermediate duration bursts during the last decade could be due to an observational bias toward detecting only the longest and most energetic bursts from slowly accreting NSs.

Compilation and evaluation of atomic and molecular data relevant to controlled thermonuclear research needs: USA programs

International Nuclear Information System (INIS)

Barnett, C.F.

1976-01-01

The U.S. role in the compilation and evaluation of atomic data for controlled thermonuclear research is discussed in the following three areas: (1) atomic structure data, (2) atomic collision data, and (3) surface data

Non-thermal DT yield with (D)T ICRH heating in JET

International Nuclear Information System (INIS)

Cottrell, G.A.; Bhatnagar, V.P.; Bures, M.; Hellsten, T.; Jacquinot, J.; Start, D.F.H.

1989-01-01

Projections of the (D)T fusion yield expected during fundamental ICRH heating of D in JET tritium plasmas are presented. The highest fusion multiplication factor, Q (≡P fus /P r.f. ), is achieved for a relatively high plasma density (n e0 > 5 x 10 19 m -3 ) and minority concentration ratio n D /n T ≅ 20-40% with dipole antenna (k || ∼ 7 m -1 ). The latter reduces mode conversion and maximizes the r.f. power coupled to the minority ions. We have used ray-tracing and global wave ICRH codes to calculate power deposition profiles; 80% is cyclotron damped by deuterium and 17% is coupled directly to electrons via TTMP and Landau damping. With launched r.f. power P r.f. = 12 MW deposited ∼ 0.3 m off-axis, we predict fusion powers P fus up to ∼ 8 MW for a range of JET plasmas with achieved plasma pressure N e0 T e0 - 6 x 10 20 keV m -3 and Z eff = 2. Projecting to P r.f. = 25 MW, P fus increases to 17 MW with Z eff = 2. (author)

Antenna design for fast ion collective Thomson scattering diagnostic for the international thermonuclear experimental reactor

DEFF Research Database (Denmark)

Leipold, Frank; Furtula, Vedran; Salewski, Mirko

2009-01-01

Fast ion physics will play an important role for the international thermonuclear experimental reactor (ITER), where confined alpha particles will affect and be affected by plasma dynamics and thereby have impacts on the overall confinement. A fast ion collective Thomson scattering (CTS) diagnostic...

Department of Thermonuclear Research annual report 1990

Energy Technology Data Exchange (ETDEWEB)

Sadowski, M [ed.

1991-03-01

Department of Thermonuclear Research Annual Report 1990 presents the most important results of theoretical, experimental, and technological studies, carried out within a framework of two programs: Diagnostics of High-Temperature Plasma (CPBP 01.10) and Nuclear Technology (CPBR 5.8). Theoretical studies of tokamak edge plasmas, charged particle motions, strong refraction effects, current pulse generators, classical models of atomic collisions, and electron mechanisms of the Coulomb barrier tunneling, are shortly summarized. Experimental studies of X-ray, ion, and proton emission from the RPI-type devices, as well as optimization tests and electron beam measurements at the PF-type facilities, are described. Technological studies of opto-electronic transmission systems, modifications of diagnostic equipment, design and construction of new PF facilities, as well as applications of the IONOTRON-type devices, are also presented. (author). 56 refs, 20 figs.

Department of Thermonuclear Research annual report 1991

Energy Technology Data Exchange (ETDEWEB)

Sadowski, M; Pawlowicz, W [eds.

1992-02-01

Department of Thermonuclear Research Annual Report 1991 presents a short review of theoretical, experimental, and technological studies carried out within the framework of two research programs: Plasma Physics and Development of Diagnostics Data Acquisition. Theoretical studies of a tokamak edge plasma, validity of inverse Abel transformation for strongly refracting objects, simulation of the pulse generators operation, and a numerical analysis of electron capture in p + H{sup +} collisions, are described. Experimental studies of corpuscular beams and X-rays from different plasma facilities, development of diagnostic techniques and of data acquisition systems, as well as experiments with the generation of cryogenic pellets for plasma research, are shortly summarized. Also presented are technological studies concerning the modernization of the PF- and RPI-type facilities and the application of the IONOTRON-type devices for the modification of semiconductor and metal surfaces. (author). 27 refs, 24 figs.

Department of Thermonuclear Research annual report 1990

International Nuclear Information System (INIS)

Sadowski, M.

1991-03-01

Department of Thermonuclear Research Annual Report 1990 presents the most important results of theoretical, experimental, and technological studies, carried out within a framework of two programs: Diagnostics of High-Temperature Plasma (CPBP 01.10) and Nuclear Technology (CPBR 5.8). Theoretical studies of tokamak edge plasmas, charged particle motions, strong refraction effects, current pulse generators, classical models of atomic collisions, and electron mechanisms of the Coulomb barrier tunneling, are shortly summarized. Experimental studies of X-ray, ion, and proton emission from the RPI-type devices, as well as optimization tests and electron beam measurements at the PF-type facilities, are described. Technological studies of opto-electronic transmission systems, modifications of diagnostic equipment, design and construction of new PF facilities, as well as applications of the IONOTRON-type devices, are also presented. (author). 56 refs, 20 figs

Department of Thermonuclear Research annual report 1991

International Nuclear Information System (INIS)

Sadowski, M.; Pawlowicz, W.

1992-02-01

Department of Thermonuclear Research Annual Report 1991 presents a short review of theoretical, experimental, and technological studies carried out within the framework of two research programs: Plasma Physics and Development of Diagnostics Data Acquisition. Theoretical studies of a tokamak edge plasma, validity of inverse Abel transformation for strongly refracting objects, simulation of the pulse generators operation, and a numerical analysis of electron capture in p + H + collisions, are described. Experimental studies of corpuscular beams and X-rays from different plasma facilities, development of diagnostic techniques and of data acquisition systems, as well as experiments with the generation of cryogenic pellets for plasma research, are shortly summarized. Also presented are technological studies concerning the modernization of the PF- and RPI-type facilities and the application of the IONOTRON-type devices for the modification of semiconductor and metal surfaces. (author). 27 refs, 24 figs

Shielding wall for thermonuclear device

International Nuclear Information System (INIS)

Uchida, Takaho.

1989-01-01

This invention concerns shielding walls opposing to plasmas of a thermonuclear device and it is an object thereof to conduct reactor operation with no troubles even if a portion of shielding wall tiles should be damaged. That is, the shielding wall tiles are constituted as a dual layer structure in which the lower base tiles are connected by means of bolts to first walls. Further, the upper surface tiles are bolt-connected to the layer base tiles. In this structure, the plasma thermal loads are directly received by the surface layer tiles and heat is conducted by means of conduction and radiation to the underlying base tiles and the first walls. Even upon occurrence of destruction accidents to the surface layer tiles caused by incident heat or electromagnetic force upon elimination of plasmas, since the underlying base tiles remain as they are, the first walls constituted with stainless steels, etc. are not directly exposed to the plasmas. Accordingly, the integrity of the first walls having cooling channels can be maintained and sputtering intrusion of atoms of high atom number into the plasmas can be prevented. (I.S.)

Shielding member for thermonuclear device

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Masanori

1997-06-30

In a thermonuclear device for shielding fast neutrons by shielding members disposed in a shielding vessel (vacuum vessel and structures such as a blanket disposed in the vacuum vessel), the shielding member comprises a large number of shielding wires formed fine and short so as to have elasticity. The shielding wires are sealed in a shielding vessel together with water, and when the width of the shielding vessel is changed, the shielding wires follow after the change of the width while elastically deforming in the shielding vessel, so that great stress and deformation are not formed thereby enabling to improve reliability. In addition, the length, the diameter and the shape of each of the shielding wires can be selected in accordance with the shielding space of the shielding vessel. Even if the shape of the shielding vessel is complicated, the shielding wires can be inserted easily. Accordingly, the filling rate of the shielding members can be changed easily. It can be produced more easily compared with a conventional spherical pebbles. It can be produced more easily than existent spherical shielding pebbles thereby enabling to reduce the production cost. (N.H.)

Divertor plate for thermonuclear reactor

International Nuclear Information System (INIS)

Yamazaki, Seiichiro; Sato, Keisuke; Nishio, Satoshi.

1993-01-01

In a divertor plate for a thermonuclear reactor, adjacent cooling pipes are electrically insulated from each other and pipes made of a gradient functional material prepared by compositing ceramics having an insulation property and metals are metallurgically joined to at least one portion of each of the cooling pipes. Electric current caused upon occurrence of plasma disruption is interrupted by the insulation portion, so that a large circuit is not formed and electromagnetic force is decreased to such a extent that the divertor plate is not ruptured. Since a header of the cooling pipes can be installed at any optional position, the installation space can be reduced. Further, since inlet and exit collection headers can be disposed on both ends of the cooling pipes, it is possible to shorten the length of the cooling pipe of the divertor plate corresponded to high heat fluxes and reduce the pressure loss on the side of coolants to about 1/2. Further, turn back portions of small radius of curvature of the cooling pipes are eliminated to reduce the cost and extend the lifetime and, in addition, protection tiles can be attached easily. (N.H.)

First wall for thermonuclear device

International Nuclear Information System (INIS)

Shibuya, Yoji.

1988-01-01

Purpose: To reduce the thermal stresses resulted to tiles and suppress the temperature rise for mounting jigs in first walls for a thermonuclear device. Constitution: A support mounting rod as a tile mounting and fixing jig and a fixing support connected therewith are disposed to the inside of an armour tile composed of high melting material and, further, a spring is disposed between the lower portion of the tile and the base plate. The armour tile can easily be fixed to the base plate by means of the resilient member by rotating the support member and abutting the support member against the support member abutting portion of the base plate. Further, since the contact and fixing surface of the armour tile and the fixing jig is situated below the tile inside the cooled base plate, the temperature rise can be suppressed as compared with the usual case. Since screw or like other clamping portion is not used for fixing the tile, heat resistant ceramics can be used with no restriction only to metal members, to thereby moderate the restriction in view of the temperature. (Kamimura, M.)

Controlled thermonuclear fusion in TOKAMAK type reactors, the European example: Joint European Torus (JET)

International Nuclear Information System (INIS)

Paris, P.J.; Yassen, F.; Assis, A.S. de; Raposo, C.

1988-07-01

The development of controlled thermonuclear reaction in TOKAMAK type reactors, and the main projects in the world are presented. The main characteristics of the JET (Joint European Torus) program, the perspectives for energy production, and the international cooperation for viable use of the TOKAMAK are analysed. (M.C.K.) [pt

Measuring the absolute DT neutron yield using the Magnetic Recoil Spectrometer at OMEGA and the NIF

Energy Technology Data Exchange (ETDEWEB)

Mackinnon, A; Casey, D; Frenje, J A; Johnson, M G; Seguin, F H; Li, C K; Petrasso, R D; Glebov, V Y; Katz, J; Knauer, J; Meyerhofer, D; Sangster, T; Bionta, R; Bleuel, D; Hachett, S P; Hartouni, E; Lepape, S; Mckernan, M; Moran, M; Yeamans, C

2012-05-03

A Magnetic Recoil Spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

LIFE Materials: Overview of Fuels and Structural Materials Issues Volume 1

Energy Technology Data Exchange (ETDEWEB)

Farmer, J

2008-09-08

The National Ignition Facility (NIF) project, a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, is under construction at the Lawrence Livermore National Laboratory (LLNL) and will be completed in April of 2009. Experiments designed to accomplish the NIF's goal will commence in late FY2010 utilizing laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 20 MJ are expected soon thereafter. Laser initiated fusion-fission (LIFE) engines have now been designed to produce nuclear power from natural or depleted uranium without isotopic enrichment, and from spent nuclear fuel from light water reactors without chemical separation into weapons-attractive actinide streams. A point-source of high-energy neutrons produced by laser-generated, thermonuclear fusion within a target is used to achieve ultra-deep burn-up of the fertile or fissile fuel in a sub-critical fission blanket. Fertile fuels including depleted uranium (DU), natural uranium (NatU), spent nuclear fuel (SNF), and thorium (Th) can be used. Fissile fuels such as low-enrichment uranium (LEU), excess weapons plutonium (WG-Pu), and excess highly-enriched uranium (HEU) may be used as well. Based upon preliminary analyses, it is believed that LIFE could help meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the nation's and world's stockpile of spent nuclear fuel and excess weapons materials. LIFE takes advantage of the significant advances in laser-based inertial confinement fusion that are taking place at the NIF at LLNL where it is expected that thermonuclear ignition will be achieved in the 2010-2011 timeframe. Starting from as little as 300 to 500 MW of fusion power, a single LIFE engine will be able to generate 2000 to 3000 MWt in steady state for periods of years to decades, depending on the nuclear fuel and engine configuration. Because the fission

Jaderná bezpečnost fúzních elektráren a jejich vliv na životní prostředí.

Czech Academy of Sciences Publication Activity Database

Entler, Slavomír; Dostál, V.

2017-01-01

Roč. 25, 9-10 (2017), s. 262-268 ISSN 1210-7085 Grant - others:AV ČR(CZ) StrategieAV21/2 Program:StrategieAV Institutional support: RVO:61389021 Keywords : design * reactor safety * thermonuclear fuel s * thermonuclear reactions * thermonuclear reactor materials * thermonuclear reactors * tokamak devices Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering

International Thermonuclear Experimental Reactor (ITER). Engineering Design Activities (EDA). Agreement and protocol 1

International Nuclear Information System (INIS)

1992-01-01

This document contains protocol 1 to the agreement among the European Atomic Energy Community, the government of Japan, the Government of the Russian Federation, and the Government of the United States of America on cooperation in the engineering design activities for the International Thermonuclear Experimental Reactor, which activities shall be conducted under the auspices of the International Atomic Energy Agency

Spatially resolved D-T(2) correlation NMR of porous media.

Science.gov (United States)

Zhang, Yan; Blümich, Bernhard

2014-05-01

Within the past decade, 2D Laplace nuclear magnetic resonance (NMR) has been developed to analyze pore geometry and diffusion of fluids in porous media on the micrometer scale. Many objects like rocks and concrete are heterogeneous on the macroscopic scale, and an integral analysis of microscopic properties provides volume-averaged information. Magnetic resonance imaging (MRI) resolves this spatial average on the contrast scale set by the particular MRI technique. Desirable contrast parameters for studies of fluid transport in porous media derive from the pore-size distribution and the pore connectivity. These microscopic parameters are accessed by 1D and 2D Laplace NMR techniques. It is therefore desirable to combine MRI and 2D Laplace NMR to image functional information on fluid transport in porous media. Because 2D Laplace resolved MRI demands excessive measuring time, this study investigates the possibility to restrict the 2D Laplace analysis to the sum signals from low-resolution pixels, which correspond to pixels of similar amplitude in high-resolution images. In this exploratory study spatially resolved D-T2 correlation maps from glass beads and mortar are analyzed. Regions of similar contrast are first identified in high-resolution images to locate corresponding pixels in low-resolution images generated with D-T2 resolved MRI for subsequent pixel summation to improve the signal-to-noise ratio of contrast-specific D-T2 maps. This method is expected to contribute valuable information on correlated sample heterogeneity from the macroscopic and the microscopic scales in various types of porous materials including building materials and rock. Copyright © 2014 Elsevier Inc. All rights reserved.

Neutron spectrometry for D-T plasmas in JET, using a tandem annular-radiator proton-recoil spectrometer

Energy Technology Data Exchange (ETDEWEB)

Hawkes, N.P.; Bond, D.S.; Kiptily, V.; Jarvis, O.N. E-mail: onj@jet.uk; Conroy, S.W

2002-01-01

A selection of the 14-MeV neutron spectra obtained at the JET Joint Undertaking tokamak during the deuterium-tritium operating campaign in 1997 are presented and analyzed. While several neutron spectrometers were operational during this campaign, the present paper is concerned solely with one: the tandem annular-radiator proton-recoil spectrometer (or proton recoil telescope, for brevity). During neutral beam heating with combined d- and t-beams, analysis of the spectra can define the core fuel composition (D:T) ratio. The spectra are sensitive to the population balance of the fast ions streaming in directions parallel and opposite to that of the injected beams. During ICRF heating of minority deuterium in bulk tritium plasmas, the spectra provide measurements of the effective temperature of the fast-deuteron energy tail and of its relative strength, which vary with the deuterium concentration. This information contributes to the overall understanding of the fusion performance of the various operating scenarios.

Implementation of the α-CHERS diagnostic for D-T operation of TFTR

International Nuclear Information System (INIS)

McKee, G.R.; Fonck, R.J.; Stratton, F.K.

1995-01-01

The α-CHERS diagnostic is a high throughput charge exchange recombination spectroscopy diagnostic designed to measure the density profile and time evolution of 0-500 keV alpha particles during D-T operation of TFTR. Following successful tests with a prototype (α-CHERS system, an improved, multi-channel system has been installed for D-T Operation. Three spatial channels may be observed simultaneously, and the spectral resolution of 0.5 nm permits increased alpha energy resolution and improved impurity line identification. More efficient coupling optics between the spectrometer and CCD detectors have increased the light throughput, and radiation shielding has been installed around the detectors and spectrometers to eliminate the neutron/gamma ray noise observed in high power D-D plasmas

Spiral Disk Instability Can Drive Thermonuclear Explosions in Binary White Dwarf Mergers

OpenAIRE

Kashyap, Rahul; Fisher, Robert; García-Berro, Enrique; Aznar-Siguán, Gabriela; Ji, Suoqing; Lorén-Aguilar, Pablo

2015-01-01

Thermonuclear, or Type Ia supernovae (SNe Ia), originate from the explosion of carbon-oxygen white dwarfs, and serve as standardizable cosmological candles. However, despite their importance, the nature of the progenitor systems that give rise to SNe Ia has not been hitherto elucidated. Observational evidence favors the double-degenerate channel in which merging white dwarf binaries lead to SNe Ia. Furthermore, significant discrepancies exist between observations and theory, and to date, ther...

Compression of an Applied Bz field by a z-pinch onto a Tamped DT Fiber for Inertial Confinement Fusion

Science.gov (United States)

Nash, Tom

2009-11-01

Simulations of a z-pinch compressing an applied 100 kG Bz field onto an on-axis DT fiber tamped with beryllium show the field reaching over 100 MG in the tamp, sufficient to confine DT alpha particles and to form a thermal barrier. The barrier allows the DT plasma to burn at a rho*r value as low as 0.045 g/cm^2, and at temperatures over 50 keV for a 63 MA drive current. Driving currents between 21 and 63 MA are considered with cryogenic DT fiber diameters between 600 μm and 1.6 mm. Pinch implosion times are 120 ns with a peak implosion velocity of 35 cm/μs. 1D simulations are of a foil pinch, but for improved stability we propose a nested wire-array. Simulated fusion yields with this system scale as the sixth power of the current, with burn fractions scaling as the fourth power of the current. At 63 MA the simulated yield is 521 MJ from 4.2 mg/cm of DT with a 37% burn fraction at a rho*r of only 0.18 g/cm^2.

First wall studies of a laser-fusion hybrid reactor design

International Nuclear Information System (INIS)

Hovingh, J.

1976-09-01

The design of a first wall for a 20 MW thermonuclear power laser fusion hybrid reactor is presented. The 20 mm thick graphite first wall is located 3.5 m from the DT microexplosion with a thermonuclear yield of 10 MJ. Estimates of the energy deposition, temperature, stresses, and material vaporized from the first wall due to the interaction of the x-rays, charged particle debris, and reflected laser light with the graphite are presented, along with a brief description of the analytical methods used for these estimations. Graphite is a viable first wall material for inertially-confined fusion reactors, with lifetimes of a year possible

Thermonuclear runaways in thick hydrogen rich envelopes of neutron stars

Science.gov (United States)

Starrfield, S. G.; Kenyon, S.; Truran, J. W.; Sparks, W. M.

1981-01-01

A Lagrangian, fully implicit, one dimensional hydrodynamic computer code was used to evolve thermonuclear runaways in the accreted hydrogen rich envelopes of 1.0 Msub solar neutron stars with radii of 10 km and 20 km. Simulations produce outbursts which last from about 750 seconds to about one week. Peak effective temeratures and luninosities were 26 million K and 80 thousand Lsub solar for the 10 km study and 5.3 millison and 600 Lsub solar for the 20 km study. Hydrodynamic expansion on the 10 km neutron star produced a precursor lasting about one ten thousandth seconds.

BAYESIAN ESTIMATION OF THERMONUCLEAR REACTION RATES

Energy Technology Data Exchange (ETDEWEB)

Iliadis, C.; Anderson, K. S. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Coc, A. [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), CNRS/IN2P3, Univ. Paris-Sud, Université Paris–Saclay, Bâtiment 104, F-91405 Orsay Campus (France); Timmes, F. X.; Starrfield, S., E-mail: iliadis@unc.edu [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1504 (United States)

2016-11-01

The problem of estimating non-resonant astrophysical S -factors and thermonuclear reaction rates, based on measured nuclear cross sections, is of major interest for nuclear energy generation, neutrino physics, and element synthesis. Many different methods have been applied to this problem in the past, almost all of them based on traditional statistics. Bayesian methods, on the other hand, are now in widespread use in the physical sciences. In astronomy, for example, Bayesian statistics is applied to the observation of extrasolar planets, gravitational waves, and Type Ia supernovae. However, nuclear physics, in particular, has been slow to adopt Bayesian methods. We present astrophysical S -factors and reaction rates based on Bayesian statistics. We develop a framework that incorporates robust parameter estimation, systematic effects, and non-Gaussian uncertainties in a consistent manner. The method is applied to the reactions d(p, γ ){sup 3}He, {sup 3}He({sup 3}He,2p){sup 4}He, and {sup 3}He( α , γ ){sup 7}Be, important for deuterium burning, solar neutrinos, and Big Bang nucleosynthesis.

Microencapsulation and fabrication of fuel pellets for inertial confinement fusion

International Nuclear Information System (INIS)

Nolen, R.L. Jr.; Kool, L.B.

1981-01-01

Various microencapsulation techniques were evaluated for fabrication of thermonuclear fuel pellets for use in existing experimental facilities studying inertial confinement fusion and in future fusion-power reactors. Coacervation, spray drying, in situ polymerization, and physical microencapsulation methods were employed. Highly spherical, hollow polymeric shells were fabricated ranging in size from 20 to 7000 micron. In situ polymerization microencapsulation with poly(methyl methacrylate) provided large shells, but problems with local wall defects still must be solved. Extension to other polymeric systems met with limited success. Requirements for inertial confinement fusion targets are described, as are the methods that were used

Frontiers in propulsion research: Laser, matter-antimatter, excited helium, energy exchange thermonuclear fusion

Science.gov (United States)

Papailiou, D. D. (Editor)

1975-01-01

Concepts are described that presently appear to have the potential for propulsion applications in the post-1990 era of space technology. The studies are still in progress, and only the current status of investigation is presented. The topics for possible propulsion application are lasers, nuclear fusion, matter-antimatter annihilation, electronically excited helium, energy exchange through the interaction of various fields, laser propagation, and thermonuclear fusion technology.

Cardiac re-entry dynamics and self-termination in DT-MRI based model of Human Foetal Heart

Science.gov (United States)

Biktasheva, Irina V.; Anderson, Richard A.; Holden, Arun V.; Pervolaraki, Eleftheria; Wen, Fen Cai

2018-02-01

The effect of human foetal heart geometry and anisotropy on anatomy induced drift and self-termination of cardiac re-entry is studied here in MRI based 2D slice and 3D whole heart computer simulations. Isotropic and anisotropic models of 20 weeks of gestational age human foetal heart obtained from 100μm voxel diffusion tensor MRI data sets were used in the computer simulations. The fiber orientation angles of the heart were obtained from the orientation of the DT-MRI primary eigenvectors. In a spatially homogeneous electrophysiological monodomain model with the DT-MRI based heart geometries, cardiac re-entry was initiated at a prescribed location in a 2D slice, and in the 3D whole heart anatomy models. Excitation was described by simplified FitzHugh-Nagumo kinetics. In a slice of the heart, with propagation velocity twice as fast along the fibres than across the fibers, DT-MRI based fiber anisotropy changes the re-entry dynamics from pinned to an anatomical re-entry. In the 3D whole heart models, the fiber anisotropy changes cardiac re-entry dynamics from a persistent re-entry to the re-entry self-termination. The self-termination time depends on the re-entry’s initial position. In all the simulations with the DT-MRI based cardiac geometry, the anisotropy of the myocardial tissue shortens the time to re-entry self-termination several folds. The numerical simulations depend on the validity of the DT-MRI data set used. The ventricular wall showed the characteristic transmural rotation of the helix angle of the developed mammalian heart, while the fiber orientation in the atria was irregular.

Radiation-induced apoptosis of chicken lymphocyte B-cell line DT40

International Nuclear Information System (INIS)

Furusawa, Y.; Aoki, M.; Takakura, K.

2003-01-01

Full text: Ionizing radiation causes lesions of DNA, cell cycle arrest, induced cell death, and apoptosis in the irradiated cells. Then it is easy to expect that those events would be increased in a cell line which is defective in DNA repair system. However, induction of apoptosis by irradiation takes so complicated process when the cells are defective of DNA repair system. Indeed by many recent studies it has been clarified that DNA repair gene is also concerned with apoptotic event and some study shows the contrary data. Thus, the relationship between the genetics of apoptosis and that of DNA repair is still unclear. In this study two kinds of DNA repair proteins, Rad54 and Ku70, were focused. Proteins of Rad54 and Ku70 have important role at two type of DNA repair systems called homologous recombination repair and non-homologous end joining repair, respectively. 4 phenotypes of DT40, parent type, ku70-/-, rad54-/- and ku70-/-/rad54-/- were used to study the radiation-induced apoptosis (Previous study shows that survival fraction of 4 phenotypes of DT40 is decreased in the cell line, in which DNA repair gene is defective). From the results in this study, two things are clarifies. One is that the dependence of apoptotic index on phenotypes is so different between at low dose and at high dose irradiation. The other is that Ku70 has effective role to induce apoptosis in DT40 irradiated with high dose X-rays

Transport simulation of ITER [International Thermonuclear Engineering Reactor] startup

International Nuclear Information System (INIS)

Attenberger, S.E.; Houlberg, W.A.

1989-01-01

The present International Thermonuclear Engineering Reactor (ITER) reference configurations are the ''Technology Phase,'' in which the plasma current is maintained noninductively at a subignition density, and the ''Physics Phase,'' which is ignited but requires inductive maintenance of the current. The WHIST 1.5-D transport code is used to evaluate the volt-second requirements of both configurations. A slow current ramp (60-80's) is required for fixed-radius startup in ITER to avoid hollow current density profiles. To reach the operating point requires about 203 V·s for the Technology Phase (18 MA) and about 270 V·s for the Physics Phase (22 MA). The resistive losses can be reduced with expanding-radius startup. 5 refs., 4 figs

Laser induced sonofusion: A new road toward thermonuclear reactions

Energy Technology Data Exchange (ETDEWEB)

Sadighi-Bonabi, Rasoul, E-mail: Sadighi@sharif.ir [Sharif University of Technology, P.O. Box 11365-91, Tehran (Iran, Islamic Republic of); Gheshlaghi, Maryam [Payame noor University, P.O. Box 19395-3697, Tehran (Iran, Islamic Republic of); Laser and optics research school, Nuclear Science and Technology Research Institute (NSTRL), P.O. Box 14155-1339, Tehran (Iran, Islamic Republic of)

2016-03-15

The Possibility of the laser assisted sonofusion is studied via single bubble sonoluminescence (SBSL) in Deuterated acetone (C{sub 3}D{sub 6}O) using quasi-adiabatic and hydro-chemical simulations at the ambient temperatures of 0 and −28.5 °C. The interior temperature of the produced bubbles in Deuterated acetone is 1.6 × 10{sup 6} K in hydro-chemical model and it is reached up to 1.9 × 10{sup 6} K in the laser induced SBSL bubbles. Under these circumstances, temperature up to 10{sup 7} K can be produced in the center of the bubble in which the thermonuclear D-D fusion reactions are promising under the controlled conditions.

Alternative hot spot formation techniques using liquid deuterium-tritium layer inertial confinement fusion capsules

International Nuclear Information System (INIS)

Olson, R. E.; Leeper, R. J.

2013-01-01

The baseline DT ice layer inertial confinement fusion (ICF) ignition capsule design requires a hot spot convergence ratio of ∼34 with a hot spot that is formed from DT mass originally residing in a very thin layer at the inner DT ice surface. In the present paper, we propose alternative ICF capsule designs in which the hot spot is formed mostly or entirely from mass originating within a spherical volume of DT vapor. Simulations of the implosion and hot spot formation in two DT liquid layer ICF capsule concepts—the DT wetted hydrocarbon (CH) foam concept and the “fast formed liquid” (FFL) concept—are described and compared to simulations of standard DT ice layer capsules. 1D simulations are used to compare the drive requirements, the optimal shock timing, the radial dependence of hot spot specific energy gain, and the hot spot convergence ratio in low vapor pressure (DT ice) and high vapor pressure (DT liquid) capsules. 2D simulations are used to compare the relative sensitivities to low-mode x-ray flux asymmetries in the DT ice and DT liquid capsules. It is found that the overall thermonuclear yields predicted for DT liquid layer capsules are less than yields predicted for DT ice layer capsules in simulations using comparable capsule size and absorbed energy. However, the wetted foam and FFL designs allow for flexibility in hot spot convergence ratio through the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density, with a potentially improved robustness to low-mode x-ray flux asymmetry

Regularization of DT-MRI Using 3D Median Filtering Methods

Directory of Open Access Journals (Sweden)

Soondong Kwon

2014-01-01

Full Text Available DT-MRI (diffusion tensor magnetic resonance imaging tractography is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of the principal eigenvectors obtained from tensor matrix, which is different from the conventional isotropic MRI. Tractography based on DT-MRI is known to need many computations and is highly sensitive to noise. Hence, adequate regularization methods, such as image processing techniques, are in demand. Among many regularization methods we are interested in the median filtering method. In this paper, we extended two-dimensional median filters already developed to three-dimensional median filters. We compared four median filtering methods which are two-dimensional simple median method (SM2D, two-dimensional successive Fermat method (SF2D, three-dimensional simple median method (SM3D, and three-dimensional successive Fermat method (SF3D. Three kinds of synthetic data with different altitude angles from axial slices and one kind of human data from MR scanner are considered for numerical implementation by the four filtering methods.

The historical record for Sirius - Evidence for a white-dwarf thermonuclear runaway?

Science.gov (United States)

Bruhweiler, Frederick C.; Kondo, Yoji; Sion, Edward M.

1986-01-01

Evidence was recently presented that in medieval times Sirius was a bright red star, rather than the present bluish-white star. Here, the results of attempts to detect possible planetary nebula ejecta toward Sirius using data obtained by the IUE are presented. Based on these results and in the light of recent advances in understanding white-dwarf evolution, it is proposed that Sirius B underwent a recent thermonuclear runaway event triggered by a diffusion-induced CN reaction.

Fuel cycle for a fusion neutron source

Science.gov (United States)

Ananyev, S. S.; Spitsyn, A. V.; Kuteev, B. V.

2015-12-01

The concept of a tokamak-based stationary fusion neutron source (FNS) for scientific research (neutron diffraction, etc.), tests of structural materials for future fusion reactors, nuclear waste transmutation, fission reactor fuel production, and control of subcritical nuclear systems (fusion-fission hybrid reactor) is being developed in Russia. The fuel cycle system is one of the most important systems of FNS that provides circulation and reprocessing of the deuterium-tritium fuel mixture in all fusion reactor systems: the vacuum chamber, neutral injection system, cryogenic pumps, tritium purification system, separation system, storage system, and tritium-breeding blanket. The existing technologies need to be significantly upgraded since the engineering solutions adopted in the ITER project can be only partially used in the FNS (considering the capacity factor higher than 0.3, tritium flow up to 200 m3Pa/s, and temperature of reactor elements up to 650°C). The deuterium-tritium fuel cycle of the stationary FNS is considered. The TC-FNS computer code developed for estimating the tritium distribution in the systems of FNS is described. The code calculates tritium flows and inventory in tokamak systems (vacuum chamber, cryogenic pumps, neutral injection system, fuel mixture purification system, isotope separation system, tritium storage system) and takes into account tritium loss in the fuel cycle due to thermonuclear burnup and β decay. For the two facility versions considered, FNS-ST and DEMO-FNS, the amount of fuel mixture needed for uninterrupted operation of all fuel cycle systems is 0.9 and 1.4 kg, consequently, and the tritium consumption is 0.3 and 1.8 kg per year, including 35 and 55 g/yr, respectively, due to tritium decay.

Fuel cycle for a fusion neutron source

Energy Technology Data Exchange (ETDEWEB)

Ananyev, S. S., E-mail: Ananyev-SS@nrcki.ru; Spitsyn, A. V., E-mail: spitsyn-av@nrcki.ru; Kuteev, B. V., E-mail: Kuteev-BV@nrcki.ru [National Research Center Kurchatov Institute (Russian Federation)

2015-12-15

The concept of a tokamak-based stationary fusion neutron source (FNS) for scientific research (neutron diffraction, etc.), tests of structural materials for future fusion reactors, nuclear waste transmutation, fission reactor fuel production, and control of subcritical nuclear systems (fusion–fission hybrid reactor) is being developed in Russia. The fuel cycle system is one of the most important systems of FNS that provides circulation and reprocessing of the deuterium–tritium fuel mixture in all fusion reactor systems: the vacuum chamber, neutral injection system, cryogenic pumps, tritium purification system, separation system, storage system, and tritium-breeding blanket. The existing technologies need to be significantly upgraded since the engineering solutions adopted in the ITER project can be only partially used in the FNS (considering the capacity factor higher than 0.3, tritium flow up to 200 m{sup 3}Pa/s, and temperature of reactor elements up to 650°C). The deuterium–tritium fuel cycle of the stationary FNS is considered. The TC-FNS computer code developed for estimating the tritium distribution in the systems of FNS is described. The code calculates tritium flows and inventory in tokamak systems (vacuum chamber, cryogenic pumps, neutral injection system, fuel mixture purification system, isotope separation system, tritium storage system) and takes into account tritium loss in the fuel cycle due to thermonuclear burnup and β decay. For the two facility versions considered, FNS-ST and DEMO-FNS, the amount of fuel mixture needed for uninterrupted operation of all fuel cycle systems is 0.9 and 1.4 kg, consequently, and the tritium consumption is 0.3 and 1.8 kg per year, including 35 and 55 g/yr, respectively, due to tritium decay.

Reaching to a featured formula to deduce the energy of the heaviest particles producing from the controlled thermonuclear fusion reactions

Science.gov (United States)

Majeed, Raad H.; Oudah, Osamah N.

2018-05-01

Thermonuclear fusion reaction plays an important role in developing and construction any power plant system. Studying the physical behavior for the possible mechanism governed energies released by the fusion products to precise understanding the related kinematics. In this work a theoretical formula controlled the general applied thermonuclear fusion reactions is achieved to calculating the fusion products energy depending upon the reactants physical properties and therefore, one can calculate other parameters governed a given reaction. By using this formula, the energy spectrum of 4He produced from T-3He fusion reaction has been sketched with respect to reaction angle and incident energy ranged from (0.08-0.6) MeV.

Department of Thermonuclear Research annual report 1992

International Nuclear Information System (INIS)

Sadowski, M.; Pawlowicz, W.

1993-02-01

Department of Thermonuclear Research annual report 1992 presents the most important results of theoretical, experimental and technological studies carried out within a framework of the research program - Plasma Physics and an additional grant - Study of Surface Melting of Selected Materials with a Plasma stream (contract with the Committee for Scientific Research - KBN). Theoretical studies of tokamak edge plasmas, atomic collisions, heat transfer, and numerical codes, are shortly summarized. Experimental studies of X-rays and particles emitted from Plasma-Focus facilities, calibration of nuclear track detectors, optimization of PF discharges with additional gas targets, magnetic probe measurements, new diagnostic and experimental arrangements, as well as mass- and energy-analysis of ions from IONOTRON-type devices, are described. Also presented are technological studies, modernization of experimental facilities, design of new control systems, tests on uniformity and reproducibility of plasma streams as the formation of photovoltaic cells and modifications of solid surfaces by means of plasma streams from the IONOTRON and PF devices. (author)

Department of Thermonuclear Research annual report 1992

Energy Technology Data Exchange (ETDEWEB)

Sadowski, M; Pawlowicz, W [eds.; Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

1993-02-01

Department of Thermonuclear Research annual report 1992 presents the most important results of theoretical, experimental and technological studies carried out within a framework of the research program - Plasma Physics and an additional grant - Study of Surface Melting of Selected Materials with a Plasma stream (contract with the Committee for Scientific Research - KBN). Theoretical studies of tokamak edge plasmas, atomic collisions, heat transfer, and numerical codes, are shortly summarized. Experimental studies of X-rays and particles emitted from Plasma-Focus facilities, calibration of nuclear track detectors, optimization of PF discharges with additional gas targets, magnetic probe measurements, new diagnostic and experimental arrangements, as well as mass- and energy-analysis of ions from IONOTRON-type devices, are described. Also presented are technological studies, modernization of experimental facilities, design of new control systems, tests on uniformity and reproducibility of plasma streams as the formation of photovoltaic cells and modifications of solid surfaces by means of plasma streams from the IONOTRON and PF devices. (author).

The International Thermonuclear Experimental Reactor configuration evolution

International Nuclear Information System (INIS)

Lousteau, D.C.; Nelson, B.E.; Lee, V.D.; Thomson, S.L.; Miller, J.M.; Lindquist, W.B.

1989-01-01

The International Thermonuclear Experimental Reactor (ITER) conceptual design activities consist of two phases: a definition phase, completed in September 1988, and a design phase, now in progress. The definition phase was successful in identifying a consistent set of technical characteristics and the broad definition of the required reactor configuration and hardware. Scheduled for completion in November 1990, the design phase is producing a more detailed definition of the required components, a first cost estimate, and a description of site requirements. A major activity in the ITER design phase is the period of joint work conducted at the Max Planck Institute for Plasma Physics, Garching, Federal Republic of Germany, from June through October 1989. An official report of the findings and conclusions of this activity will be submitted to and published by the International Atomic Energy Agency (IAEA). This paper highlights the evolution of the reactor mechanical configuration since the conclusion of the definition phase. 8 figs., 2 tabs

Vacuum exhaust duct used for thermonuclear device

International Nuclear Information System (INIS)

Tachikawa, Nobuo; Kondo, Mitsuaki; Honda, Tsutomu.

1990-01-01

The present invention concerns a vacuum exhaust duct used for a thermonuclear device. A cylindrical metal liners is lined with a gap to the inside of a vacuum exhaust duct main body. Bellows are connected to both ends of the metal liners and the end of the bellows is welded to the vacuum exhaust duct main body. Futher, a heater is mounted to the metal liner on the side of the vacuum exhaust duct main body, and the metal liner is heated by the heater to conduct baking for the vacuum exhaust duct main body. Accordingly, since there is no requirement for elevating the temperature of the vacuum exhaust duct upon conducting baking, the vacuum exhaust duct scarcely suffers substantial deformation due to heat expansion. Further, there is also no substantial deformation for the bellows disposed between the outer circumference of the vacuum vessel and a portion of a vacuum exhaust duct, so that the durability of the bellows is greatly improved. (I.S.)

Alpha-particle diagnostics for the D-T phase

Energy Technology Data Exchange (ETDEWEB)

Conroy, S.W.; Bergsaker, H.; Coad, J.P.; Jarvis, O.N.; Marcus, F.B.; Sadler, G.; Belle, P. van (Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking); McCracken, G.M.; Pitts, R.A. (AEA Fusion, Culham (United Kingdom)); Zhu, J. (Sussex Univ., Brighton (United Kingdom))

1991-01-01

Diagnostics to examine the lost [alpha] particle flux at JET during the D-T phase are under development. A passive [sup 3]He collector probe has been tested during [sup 3]He NBI and RF heated discharges. [sup 3]He ions with energies of at least 100 keV have been detected; their source is probably due to the metastable component of the [sup 3]He NBI. A code has been developed to model the charged particle fluxes at the wall. (author) 5 refs., 4 figs.

Matching of experimental and statistical-model thermonuclear reaction rates at high temperatures

International Nuclear Information System (INIS)

Newton, J. R.; Longland, R.; Iliadis, C.

2008-01-01

We address the problem of extrapolating experimental thermonuclear reaction rates toward high stellar temperatures (T>1 GK) by using statistical model (Hauser-Feshbach) results. Reliable reaction rates at such temperatures are required for studies of advanced stellar burning stages, supernovae, and x-ray bursts. Generally accepted methods are based on the concept of a Gamow peak. We follow recent ideas that emphasized the fundamental shortcomings of the Gamow peak concept for narrow resonances at high stellar temperatures. Our new method defines the effective thermonuclear energy range (ETER) by using the 8th, 50th, and 92nd percentiles of the cumulative distribution of fractional resonant reaction rate contributions. This definition is unambiguous and has a straightforward probability interpretation. The ETER is used to define a temperature at which Hauser-Feshbach rates can be matched to experimental rates. This matching temperature is usually much higher compared to previous estimates that employed the Gamow peak concept. We suggest that an increased matching temperature provides more reliable extrapolated reaction rates since Hauser-Feshbach results are more trustwhorthy the higher the temperature. Our ideas are applied to 21 (p,γ), (p,α), and (α,γ) reactions on A=20-40 target nuclei. For many of the cases studied here, our extrapolated reaction rates at high temperatures differ significantly from those obtained using the Gamow peak concept

Nuclear-reaction rates in the thermonuclear runaway phase of accreting neutron stars

International Nuclear Information System (INIS)

Wiescher, M.; Barnard, V.; Goerres, J.; Fisker, J.L.; Martinez-Pinedo, G.; Langanke, K.; Rembges, F.; Thielemann, F.K.; Schatz, H.

2002-01-01

The rp-process has been suggested as the dominant nucleosynthesis process in explosive hydrogen burning at high temperature and density conditions. The process is characterized by a sequence of fast proton capture reactions and subsequent β-decays. The reaction path of the rp-process runs along the drip line up to Z∼50. Most of the charged-particle reaction rates for the reaction path are presently based on statistical Hauser-Feshbach calculations. While these rates are supposed to be reliable within a factor of two for conditions of high density in the compound nuclei, discrepancies may occur for nuclei near closed shells or near the proton drip line where the Q-values of proton capture processes are typically very small. It has been argued that the thermonuclear runaway is less sensitive to the reaction rates because of the rapid time-scale of the event. However, since these processes may operate at the same time-scale as fast mixing and convection processes, a change in reaction rates indeed may have a significant impact. In this paper we present two examples, the break-out from the hot CNO cycles, and the thermonuclear runaway in X-ray bursts itself, where changes in reaction rates have a direct impact on time-scale, energy generation and nucleosynthesis predictions for the explosive event. (orig.)

HYPERFUSE: a novel inertial confinement system utilizing hypervelocity projectiles for fusion energy production and fission waste transmutation

International Nuclear Information System (INIS)

Makowitz, H.; Powell, J.R.; Wiswall, R.

1980-01-01

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with each other or a target block in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs or 90 Sr. The 14-MeV fusion neutrons released during the pellet burn cause transmutation reactions (e.g., (n, 2n), (n, α), etc.) that convert the long lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product

Hyper fuse: a novel inertial confinement system utilizing hypervelocity projectiles for fusion energy production and fission waste transmutation

International Nuclear Information System (INIS)

Makowitz, H.; Powell, J.R.; Wiswall, R.

1979-01-01

Parametric system studies of an inertial confinement fusion (ICF) reactor system to transmute fission products from an LWR economy have been carried out. The ICF reactors would produce net power in addition to transmuting fission products. The particular ICF concept examined is an impact fusion approach termed HYPERFUSE, in which hypervelocity pellets, traveling on the order of 100 to 300 km/sec, collide with a target in a reactor chamber and initiate a thermonuclear reaction. The DT fusion fuel is contained in a shell of the material to be transmuted, e.g., 137 Cs or 90 Sr. The 14 MeV fusion neutrons released during the pellet burn cause transmutation reactions [e.g., (n, 2n), (n, α), etc.] that convert the long lived fission products (FP's) either to stable products or to species that decay with a short half-life to a stable product

Benchmark testing and independent verification of the VS2DT computer code

International Nuclear Information System (INIS)

McCord, J.T.

1994-11-01

The finite difference flow and transport simulator VS2DT was benchmark tested against several other codes which solve the same equations (Richards equation for flow and the Advection-Dispersion equation for transport). The benchmark problems investigated transient two-dimensional flow in a heterogeneous soil profile with a localized water source at the ground surface. The VS2DT code performed as well as or better than all other codes when considering mass balance characteristics and computational speed. It was also rated highly relative to the other codes with regard to ease-of-use. Following the benchmark study, the code was verified against two analytical solutions, one for two-dimensional flow and one for two-dimensional transport. These independent verifications show reasonable agreement with the analytical solutions, and complement the one-dimensional verification problems published in the code's original documentation

A continuous tensor field approximation of discrete DT-MRI data for extracting microstructural and architectural features of tissue.

Science.gov (United States)

Pajevic, Sinisa; Aldroubi, Akram; Basser, Peter J

2002-01-01

The effective diffusion tensor of water, D, measured by diffusion tensor MRI (DT-MRI), is inherently a discrete, noisy, voxel-averaged sample of an underlying macroscopic effective diffusion tensor field, D(x). Within fibrous tissues this field is presumed to be continuous and smooth at a gross anatomical length scale. Here a new, general mathematical framework is proposed that uses measured DT-MRI data to produce a continuous approximation to D(x). One essential finding is that the continuous tensor field representation can be constructed by repeatedly performing one-dimensional B-spline transforms of the DT-MRI data. The fidelity and noise-immunity of this approximation are tested using a set of synthetically generated tensor fields to which background noise is added via Monte Carlo methods. Generally, these tensor field templates are reproduced faithfully except at boundaries where diffusion properties change discontinuously or where the tensor field is not microscopically homogeneous. Away from such regions, the tensor field approximation does not introduce bias in useful DT-MRI parameters, such as Trace(D(x)). It also facilitates the calculation of several new parameters, particularly differential quantities obtained from the tensor of spatial gradients of D(x). As an example, we show that they can identify tissue boundaries across which diffusion properties change rapidly using in vivo human brain data. One important application of this methodology is to improve the reliability and robustness of DT-MRI fiber tractography.

Monte Carlo simulations of a D-T neutron generator shielding for landmine detection

International Nuclear Information System (INIS)

Reda, A.M.

2011-01-01

Shielding for a D-T sealed neutron generator has been designed using the MCNP5 Monte Carlo radiation transport code. The neutron generator will be used in field for the detection of explosives, landmines, drugs and other 'threat' materials. The optimization of the detection of buried objects was started by studying the signal-to-noise ratio for different geometric conditions. - Highlights: → A landmine detection system based on neutron fast/slow analysis has been designed. → Shielding for a D-T sealed neutron generator tube has been designed using Monte Carlo radiation transport code. → Detection of buried objects was started by studying the signal-to-noise ratio for different geometric conditions. → The signal-to-background ratio optimized at one position for all depths.

Structure of pipeline or duct for thermonuclear reactor

International Nuclear Information System (INIS)

Yamazaki, Seiichiro; Kobayashi, Takeshi; Fujioka, Junzo; Nishio, Satoshi; Okawa, Yoshinao; Sato, Keisuke.

1992-01-01

An electrically insulating material comprising a gradient function material is bonded metallurgically to a pipeline or a duct to be disposed to a magnetic field-confining type thermonuclear reactor. The gradient material has an ingredient approximate to ceramics on the side of an electrically insulative ceramic portion and an ingredient approximate to a metal on the other side. The intermediate portion between them, has a continuous gradient ingredient. Further, in the gradient portion of the electrically insulative portion, a heat expansion coefficient is also varied continuously or stepwise in addition to the electrical insulative property. Accordingly, even when a temperature distribution is caused during operation and welding upon production, thermal stresses applied to the pipelines is moderated. Further, since the electrically insulative ceramics are interposed with no support by an electric conductor, sufficient electrical insulation can be ensured. (T.M.)

Generation of thermonuclear fusion neutrons by means of a pure explosion. Part 2. Experimental results

International Nuclear Information System (INIS)

Derentowicz, H.; Kaliski, S.; Wolski, J.; Ziolkowski, Z.

1977-01-01

This paper presents the experimental results of the generation of a thermonuclear fusion neutrons by means of explosion. The experimental set is based on a quasi-spherical experiment in which a polyethylene layer is shot into a conic region hollowed out in a golden target and filled with deuterium gas. The speeding-up system is based on shooting the conic liner onto the surface of the Cu cone in which the Mach wave is generated and propagates along the cone axis leading to an implosion velocity of the polyethylene layer of the order of (4 - 5).10 6 cm/s. This affords a 10 3 -multiple compression of the D 2 gas (p 0 approximately 1.2 atm) and a neutron emission of the order of 3.10 7 from a mass of about 10 -7 g. This result is in full agreement with theoretical estimates. This is the first published and documented experiment in which a neutron stream of thermonuclear fusion was obtained by means of a pure explosion. (author)

High-speed repetitive pellet injector for plasma fueling of magnetic confinement fusion devices

International Nuclear Information System (INIS)

Combs, S.K.; Baylor, L.R.; Foust, C.R.

1993-01-01

The projected fueling requirements of future magnetic confinement devices for controlled thermonuclear research [e.g., the International Thermonuclear Experimental Reactor (ITER)] indicate that a flexible plasma fueling capability is required. This includes a mix of traditional gas puffing and low- and high-velocity deuterium-tritium pellets. Conventional pellet injectors (based on light gas guns or centrifugal accelerators) can reliably provide frozen hydrogen pellets (1- to 6-mm-diam sizes tested) up to ∼1.3-km/s velocity at the appropriate pellet fueling rates (1 to 10 Hz or greater). For long-pulse operation in a higher velocity regime (>2 km/s), an experiment in collaboration between Oak Ridge National Laboratory (ORNL) and ENEA Frascati is under way. This activity will be carried out in the framework of a collaborative agreement between the US Department of Energy and European Atomic Energy Community -- ENEA Association. In this experiment, an existing ORNL hydrogen extruder (equipped with a pellet chambering mechanism/gun barrel assembly) and a Frascati two-stage light gas gun driver have been combined on a test facility at ORNL. Initial testing has been carried out with single deuterium pellets accelerated up to 2.05 km/s with the two-stage driver; in addition, some preliminary repetitive testing (to commission the diagnostics) was performed at reduced speeds, including sequences at 0.5 to 1 Hz and 10 to 30 pellets. The primary objective of this study is to demonstrate repetitive operation (up to ∼1 Hz) with speeds in the 2- to 3-km/s range. In addition, the strength of extruded hydrogen ice as opposed to that produced in situ by direct condensation in pipe guns can be investigated. The equipment and initial experimental results are described

ITER [International Thermonuclear Experimental Reactor] reactor building design study

International Nuclear Information System (INIS)

Thomson, S.L.; Blevins, J.D.; Delisle, M.W.

1989-01-01

The International Thermonuclear Experimental Reactor (ITER) is at the midpoint of a two-year conceptual design. The ITER reactor building is a reinforced concrete structure that houses the tokamak and associated equipment and systems and forms a barrier between the tokamak and the external environment. It provides radiation shielding and controls the release of radioactive materials to the environment during both routine operations and accidents. The building protects the tokamak from external events, such as earthquakes or aircraft strikes. The reactor building requirements have been developed from the component designs and the preliminary safety analysis. The equipment requirements, tritium confinement, and biological shielding have been studied. The building design in progress requires continuous iteraction with the component and system designs and with the safety analysis. 8 figs

Fusion energy from the Moon for the twenty-first century

International Nuclear Information System (INIS)

Kulcinski, G.L.; Cameron, E.N.; Santarius, J.F.; Sviatoslavsky, I.N.; Wittenberg, L.J.; Schmitt, H.H.

1992-01-01

It is shown in this paper that the D-He-3 fusion fuel cycle is not only credible from a physics standpoint, but that its breakeven and ignition characteristics could be developed on roughly the same time schedule as the DT cycle. It was also shown that the extremely low fraction of power in neutrons, the lack of significant radioactivity in the reactants, and the potential for very high conversion efficiencies, can result in definite advantages for the D-He-3 cycle with respect to DT fusion and fission reactors in the twenty-first century. More specifically, the D-He-3 cycle can accomplish the following: (1) eliminate the need for deep geologic waste burial facilities and the wastes can qualify for Class A, near-surface land burial; (2) allow inherently safe reactors to be built that, under the worst conceivable accident, cannot cause a civilian fatality or result in a significant (greater than 100 mrem) exposure to a member of the public; (3) reduce the radiation damage levels to a point where no scheduled replacement of reactor structural components is required, i.e., full reactor lifetimes (approximately 30 FPY) can be credibly claimed; (4) increase the reliability and availability of fusion reactors compared to DT systems because of the greatly reduced radioactivity, the low neutron damage, and the elimination of T breeding; and (5) greatly reduce the capital costs of fusion power plants (compared to DT systems) by as much as 50 percent and present the potential for a significant reduction on the COE. The concepts presented in this paper tie together two of the most ambitious high-technology endeavors of the twentieth century: the development of controlled thermonuclear fusion for civilian power applications and the utilization of outer space for the benefit of mankind on Earth

Calculations to support JET neutron yield calibration: Modelling of neutron emission from a compact DT neutron generator

Science.gov (United States)

Čufar, Aljaž; Batistoni, Paola; Conroy, Sean; Ghani, Zamir; Lengar, Igor; Milocco, Alberto; Packer, Lee; Pillon, Mario; Popovichev, Sergey; Snoj, Luka; JET Contributors

2017-03-01

At the Joint European Torus (JET) the ex-vessel fission chambers and in-vessel activation detectors are used as the neutron production rate and neutron yield monitors respectively. In order to ensure that these detectors produce accurate measurements they need to be experimentally calibrated. A new calibration of neutron detectors to 14 MeV neutrons, resulting from deuterium-tritium (DT) plasmas, is planned at JET using a compact accelerator based neutron generator (NG) in which a D/T beam impinges on a solid target containing T/D, producing neutrons by DT fusion reactions. This paper presents the analysis that was performed to model the neutron source characteristics in terms of energy spectrum, angle-energy distribution and the effect of the neutron generator geometry. Different codes capable of simulating the accelerator based DT neutron sources are compared and sensitivities to uncertainties in the generator's internal structure analysed. The analysis was performed to support preparation to the experimental measurements performed to characterize the NG as a calibration source. Further extensive neutronics analyses, performed with this model of the NG, will be needed to support the neutron calibration experiments and take into account various differences between the calibration experiment and experiments using the plasma as a source of neutrons.

Calculations to support JET neutron yield calibration: Modelling of neutron emission from a compact DT neutron generator

Energy Technology Data Exchange (ETDEWEB)

Čufar, Aljaž, E-mail: aljaz.cufar@ijs.si [Reactor Physics Department, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Batistoni, Paola [ENEA, Department of Fusion and Nuclear Safety Technology, I-00044 Frascati, Rome (Italy); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Conroy, Sean [Uppsala University, Department of Physics and Astronomy, PO Box 516, SE-75120 Uppsala (Sweden); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Ghani, Zamir [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Lengar, Igor [Reactor Physics Department, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Milocco, Alberto; Packer, Lee [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Pillon, Mario [ENEA, Department of Fusion and Nuclear Safety Technology, I-00044 Frascati, Rome (Italy); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Popovichev, Sergey [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Snoj, Luka [Reactor Physics Department, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); EUROfusion Consortium, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

2017-03-01

At the Joint European Torus (JET) the ex-vessel fission chambers and in-vessel activation detectors are used as the neutron production rate and neutron yield monitors respectively. In order to ensure that these detectors produce accurate measurements they need to be experimentally calibrated. A new calibration of neutron detectors to 14 MeV neutrons, resulting from deuterium–tritium (DT) plasmas, is planned at JET using a compact accelerator based neutron generator (NG) in which a D/T beam impinges on a solid target containing T/D, producing neutrons by DT fusion reactions. This paper presents the analysis that was performed to model the neutron source characteristics in terms of energy spectrum, angle–energy distribution and the effect of the neutron generator geometry. Different codes capable of simulating the accelerator based DT neutron sources are compared and sensitivities to uncertainties in the generator's internal structure analysed. The analysis was performed to support preparation to the experimental measurements performed to characterize the NG as a calibration source. Further extensive neutronics analyses, performed with this model of the NG, will be needed to support the neutron calibration experiments and take into account various differences between the calibration experiment and experiments using the plasma as a source of neutrons.

Tritium Decontamination of TFTR D-T Graphite Tiles Employing Ultra Violet Light and a Nd:YAG Laser

International Nuclear Information System (INIS)

Gentile, C.A.; Skinner, C.H.; Young, K.M.; Ciebiera, L.

1999-01-01

The use of an ultra violet (UV) light source (wavelength = 172 nm) and a Nd:YAG Laser for the decontamination of the Tokamak Fusion Test Reactor (TFTR) deuterium-tritium (D-T) tiles will be investigated at the Princeton Plasma Physics Laboratory (PPPL). The development of this form of tritium decontamination may be useful for future D-T burning fusion devices which employ carbon plasma-facing components on the first wall. Carbon tiles retain hydrogen isotopes, and the in-situ tritium decontamination of carbon can be extremely important in maintaining resident in-vessel tritium inventory to a minimum. A test chamber has been designed and fabricated at PPPL. The chamber has the ability to be maintained under vacuum, be baked to 200 *C, and provides sample ports for gas analyses. Tiles from TFTR that have been exposed to D-T plasmas will be placed within the chamber and exposed to either an UV light source or the ND:YAG Laser. The experiment will determine the effectiveness of these two techniques for the removal of tritium. In addition, exposure rates and scan times for the UV light source and/or Nd:YAG Laser will be determined for tritium removal optimization from D-T tiles

Status of IVO-FR2-Vg7 experiment for irradiation of fast reactor fuel rods

International Nuclear Information System (INIS)

Elbel, H.; Kummerer, K.; Bojarsky, K.; Lopez Jimenez, J.; Otero de la Gandara, J.L.

1979-01-01

Report on the Seminar celebrated in Madrid between KfK (Karlsruhe) and JEN (Madrid) concerning a Joint Irradiation Program of Fast Reactor Fuel Rods. The design of fuel rods in general is defined, and, in particular of those with a density 94% DT and diameter 7.6 mm up to a burn-up of 7% FIMA, to be irradiated in the FR2 Reactor (Karlsruhe). Together with the design of NaK and single-wall capsules used in this irradiation, other possibilities of irradiation in the reactor will also be described. (auth.)

Thermonuclear generation program: risks and safety

International Nuclear Information System (INIS)

Goes, Alexandre Gromann de Araujo

1999-01-01

This work deals with the fundamental concepts of risk and safety related to nuclear power generation. In the first chapter, a general evaluation of the various systems for energy generation and their environmental impacts is made. Some definitions for safety and risk are suggested, based on the already existing regulatory processes and also on the current tendencies of risk management. Aspects regarding the safety culture are commented. The International Nuclear Event Scale (INES), a coherent and clear mechanism of communication between nuclear specialists and the general public, is analyzed. The second chapter examines the thermonuclear generation program in Brazil and the role of the National Nuclear Energy Commission. The third chapter presents national and international scenarios in terms of safety and risks, available policies and the main obstacles for future development of nuclear energy and nuclear engineering, and strategies are proposed. In the last chapter, comments about possible trends and recommendations related to practical risk management procedures, taking into account rational criteria for resources distribution and risk reduction are made, envisaging a closer integration between nuclear specialists and the society as a whole, thus decreasing the conflicts in a democratic decision-making process

Radionuclide left ventricular dV/dt for the assessment of cardiac function in patients with coronary disease. [/sup 99m/Ic-labelled red blood cells and contrast radiography

Energy Technology Data Exchange (ETDEWEB)

Bianco, J.A.; Makey, D.G.; Laskey, W.K.; Shafer, R.B.

1979-01-01

To investigate potential uses of left-ventricular (LV) systolic ejection rate (LV dV/dt) in the evaluation of LV function, we examined the effect of exercise, angiotensin, and leg raising on LV ejection fraction and LV dV/dt in patients with coronary-artery disease. The following observations were made: (a) LV ejection fraction and dV/dt changed proportionately, but in opposite directions, during supine exercise; (b) LV ejection fraction and dV/dt decreased to a similar extent during angiotensin infusions; and (c) LV ejection fraction and dV/dt were unchanged by leg raising. The changes in peak and mean LV dV/dt were similar. Regardless of the physiologic state, peak LV dV/dt occurred during the first third of systole. These data imply that in this population there were no specific advantages of LV dV/dt over LV ejection fraction in the evaluation of LV performance.

Operation and control of ITER plasmas

International Nuclear Information System (INIS)

2001-01-01

Features incorporated in the design of the International Thermonuclear Experimental Reactor (ITER) tokamak and its ancillary and plasma diagnostic systems that will facilitate operation and control of ignited and/or high-Q DT plasmas are presented. Control methods based upon straight-forward extrapolation of techniques employed in the present generation of tokamaks are found to be adequate and effective for DT plasma control with burn durations of ≥1000 s. Examples of simulations of key plasma control functions including magnetic configuration control and fusion burn (power) control are given. The prospects for the creation and control of steady-state plasmas sustained by non-inductive current drive are also discussed. (author)

Operation and control of ITER plasmas

International Nuclear Information System (INIS)

1999-01-01

Features incorporated in the design of the International Thermonuclear Experimental Reactor (ITER) tokamak and its ancillary and plasma diagnostic systems that will facilitate operation and control of ignited and/or high-Q DT plasmas are presented. Control methods based upon straight-forward extrapolation of techniques employed in the present generation of tokamaks are found to be adequate and effective for DT plasma control with burn durations of ≥1000 s. Examples of simulations of key plasma control functions including magnetic configuration control and fusion burn (power) control are given. The prospects for the creation and control of steady-state plasmas sustained by non-inductive current drive are also discussed. (author)

Alpha-Driven MHD and MHD-Induced Alpha Loss in TFTR DT Experiments

Science.gov (United States)

Chang, Zuoyang

1996-11-01

Theoretical calculation and numerical simulation indicate that there can be interesting interactions between alpha particles and MHD activity which can adversely affect the performance of a tokamak reactor (e.g., ITER). These interactions include alpha-driven MHD, like the toroidicity-induced-Alfven-eigenmode (TAE) and MHD induced alpha particle losses or redistribution. Both phenomena have been observed in recent TFTR DT experiments. Weak alpha-driven TAE activity was observed in a NBI-heated DT experiment characterized by high q0 ( >= 2) and low core magnetic shear. The TAE mode appears at ~30-100 ms after the neutral beam turning off approximately as predicted by theory. The mode has an amplitude measured by magnetic coils at the edge tildeB_p ~1 mG, frequency ~150-190 kHz and toroidal mode number ~2-3. It lasts only ~ 30-70 ms and has been seen only in DT discharges with fusion power level about 1.5-2.0 MW. Numerical calculation using NOVA-K code shows that this type of plasma has a big TAE gap. The calculated TAE frequency and mode number are close to the observation. (2) KBM-induced alpha particle loss^1. In some high-β, high fusion power DT experiments, enhanced alpha particle losses were observed to be correlated to the high frequency MHD modes with f ~100-200 kHz (the TAE frequency would be two-times higher) and n ~5-10. These modes are localized around the peak plasma pressure gradient and have ballooning characteristics. Alpha loss increases by 30-100% during the modes. Particle orbit simulations show the added loss results from wave-particle resonance. Linear instability analysis indicates that the plasma is unstable to the kinetic MHD ballooning modes (KBM) driven primarily by strong local pressure gradients. ----------------- ^1Z. Chang, et al, Phys. Rev. Lett. 76 (1996) 1071. In collaberation with R. Nazikian, G.-Y. Fu, S. Batha, R. Budny, L. Chen, D. Darrow, E. Fredrickson, R. Majeski, D. Mansfield, K. McGuire, G. Rewoldt, G. Taylor, R. White, K

Arrival at CERN of the first MB4 DT chambers from Turin

CERN Multimedia

Marcos Fernandez Garcia

2005-01-01

The largest DT chambers to be installed into the outermost station of the CMS barrel muon detector (MB4) are built by INFN-Turin. The first batch of four chambers, out of 40, arrived at the CERN ISR area on February 2005.

Molecular epidemiology and antimicrobial resistance of Salmonella Typhimurium DT104 on Ontario swine farms

Science.gov (United States)

Farzan, Abdolvahab; Friendship, Robert M.; Poppe, Cornelis; Martin, Laura; Dewey, Catherine E.; Funk, Julie

2008-01-01

This study was conducted to examine antimicrobial resistances, plasmid profiles, and pulsed-field gel electrophoresis patterns of 80 Salmonella Typhimurium (including var. Copenhagen) DT104 strains (including DT104a and DT104b) recovered from pig and environmental fecal samples on 17 swine farms in Ontario. No resistance was observed to amoxicillin/clavulanic acid, apramycin, carbadox, cephalothin, ceftriaxone, ceftiofur, cefoxitin, ciprofloxacin, nalidixic acid, trimethoprim, and tobramycin. However, the isolates exhibited resistance against 4 to 10 antimicrobials with the most frequent resistance being to sulfonamides (Su), ampicillin (A), streptomycin (S), spectinomycin (Sp), chloramphenicol (C), tetracycline (T), and florfenicol (F). Thirteen distinct resistance patterns were determined but 88% of isolates shared the typical resistance pattern “ACSpSSuT.” Twelve different plasmid profiles were observed; the 62 MDa virulence-associated plasmid was detected in 95% of the isolates. The 2.1 MDa plasmid was the second most frequent one, which was harbored by 65% isolates. The isolates were classified into 23 distinct genotypes by PFGE-SpeI + BlnI when difference in at least one fragment was defined as a distinct genotype. In total, 39 distinct “types” were observed when defining a “type” based on the combination of antimicrobial resistance, plasmid pattern, and PFGE-SpeI + BlnI for each isolate. The highest diversity was 0.96 (95% CI: 0.92, 0.96) for the “type” described above followed by 0.92 (95% CI: 0.88, 0.93) for PFGE-SpeI + BlnI. The diversity of DT104 isolates indicates there might be multiple sources for this microorganism on swine farms. This knowledge might be used to track these sources, as well as to study the extent of human salmonellosis attributed to pork compared to food products derived from other food-producing animals. PMID:18505209

Regularization of DT-MR images using a successive Fermat median filtering method.

Science.gov (United States)

Kwon, Kiwoon; Kim, Dongyoun; Kim, Sunghee; Park, Insung; Jeong, Jaewon; Kim, Taehwan; Hong, Cheolpyo; Han, Bongsoo

2008-05-21

Tractography using diffusion tensor magnetic resonance imaging (DT-MRI) is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of greatest diffusion in the white matter of the brain. To reduce the noise in DT-MRI measurements, a tensor-valued median filter, which is reported to be denoising and structure preserving in the tractography, is applied. In this paper, we proposed the successive Fermat (SF) method, successively using Fermat point theory for a triangle contained in the two-dimensional plane, as a median filtering method. We discussed the error analysis and numerical study about the SF method for phantom and experimental data. By considering the computing time and the image quality aspects of the numerical study simultaneously, we showed that the SF method is much more efficient than the simple median (SM) and gradient descents (GD) methods.

Regularization of DT-MR images using a successive Fermat median filtering method

International Nuclear Information System (INIS)

Kwon, Kiwoon; Kim, Dongyoun; Kim, Sunghee; Park, Insung; Jeong, Jaewon; Kim, Taehwan; Hong, Cheolpyo; Han, Bongsoo

2008-01-01

Tractography using diffusion tensor magnetic resonance imaging (DT-MRI) is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of greatest diffusion in the white matter of the brain. To reduce the noise in DT-MRI measurements, a tensor-valued median filter, which is reported to be denoising and structure preserving in the tractography, is applied. In this paper, we proposed the successive Fermat (SF) method, successively using Fermat point theory for a triangle contained in the two-dimensional plane, as a median filtering method. We discussed the error analysis and numerical study about the SF method for phantom and experimental data. By considering the computing time and the image quality aspects of the numerical study simultaneously, we showed that the SF method is much more efficient than the simple median (SM) and gradient descents (GD) methods

Regularization of DT-MR images using a successive Fermat median filtering method

Energy Technology Data Exchange (ETDEWEB)

Kwon, Kiwoon; Kim, Dongyoun; Kim, Sunghee; Park, Insung; Jeong, Jaewon; Kim, Taehwan [Department of Biomedical Engineering, Yonsei University, Wonju, 220-710 (Korea, Republic of); Hong, Cheolpyo; Han, Bongsoo [Department of Radiological Science, Yonsei University, Wonju, 220-710 (Korea, Republic of)], E-mail: bshan@yonsei.ac.kr

2008-05-21

Tractography using diffusion tensor magnetic resonance imaging (DT-MRI) is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of greatest diffusion in the white matter of the brain. To reduce the noise in DT-MRI measurements, a tensor-valued median filter, which is reported to be denoising and structure preserving in the tractography, is applied. In this paper, we proposed the successive Fermat (SF) method, successively using Fermat point theory for a triangle contained in the two-dimensional plane, as a median filtering method. We discussed the error analysis and numerical study about the SF method for phantom and experimental data. By considering the computing time and the image quality aspects of the numerical study simultaneously, we showed that the SF method is much more efficient than the simple median (SM) and gradient descents (GD) methods.

In depth fusion flame spreading with a deuterium—tritium plane fuel density profile for plasma block ignition

International Nuclear Information System (INIS)

Malekynia, B.; Razavipour, S. S.

2012-01-01

Solid-state fuel ignition was given by Chu and Bobin according to the hydrodynamic theory at x = 0 qualitatively. A high threshold energy flux density, i.e., E* = 4.3 × 10 12 J/m 2 , has been reached. Recently, fast ignition by employing clean petawatt—picosecond laser pulses was performed. The anomalous phenomena were observed to be based on suppression of prepulses. The accelerated plasma block was used to ignite deuterium—tritium fuel at solid-state density. The detailed analysis of the thermonuclear wave propagation was investigated. Also the fusion conditions at x ≠ 0 layers were clarified by exactly solving hydrodynamic equations for plasma block ignition. In this paper, the applied physical mechanisms are determined for nonlinear force laser driven plasma blocks, thermonuclear reaction, heat transfer, electron—ion equilibration, stopping power of alpha particles, bremsstrahlung, expansion, density dependence, and fluid dynamics. New ignition conditions may be obtained by using temperature equations, including the density profile that is obtained by the continuity equation and expansion velocity. The density is only a function of x and independent of time. The ignition energy flux density, E* t , for the x ≠ 0 layers is 1.95 × 10 12 J/m 2 . Thus threshold ignition energy in comparison with that at x = 0 layers would be reduced to less than 50 percent. (physics of gases, plasmas, and electric discharges)

μ CF Study of D/T and H/D/T Mixtures in Homogeneous and Inhomogeneous Medium, and Comparison of Their Fusion Yields

Science.gov (United States)

Eskandari, M. R.; Faghihi, F.; Gheisari, R.

Muon reactivation coefficient are determined for muonic He (He = 42He = α , He = 23 He = h) for up to six (n = 1, 2, 3, ..., 6) states of formation and at temperature Tp = 100 eV and for various relative ion densities. In the next decade it may be possible to explore new conditions for further energy gain in muon catalyzed fusion system, μ CF, using nonuniform (temperature and density) plasma states. Here, we have considered a model for inhomogeneous μ CF for mixtures of D/T and H/D/T. Using coupled dynamical equations it is shown that the neutrons yield per muon injection, Yn (neutrons/muon), in the dt branch of an inhomogeneous H/D/T mixture is at least 2.24 times higher than similar homogeneous systems and this rate for a D/T mixture is 1.92. Also, we have compared the neutron yield in the dt branch of homogeneous D/T and H/D/T mixtures (temperature range T = 300-800 K, and density φ = 1 LHD). It is shown that Yn(D/T)/Yn(H/D/T) = 1.32, which is in good agreement with recently measured experimental values. In other words our calculations show that the addition of protonium to a D/T mixture leads to a significant decrease in the cycling rate for the physical conditions described herein.

A high-recycle divertor for ITER [International Thermonuclear Experimental Reactor

International Nuclear Information System (INIS)

Werley, K.A.; Bathke, C.G.

1988-01-01

A coupled one-dimensional (axial/radial) edge-plasma model (SOLAR) has been used to investigate tradeoffs between collector-plate and edge-plasma conditions in a doublenull, open, high-recycle divertor (HRD) for a preliminary International Thermonuclear Experimental Reactor (ITER) design. A steady-state HRD produces in attractive high-density edge plasma (5 /times/ 10 19 m/sup /minus/3/) with sufficiently low plasma temperature (10-20eV) at a tungsten plat that the sheath-accelerated ions are below sputtering threshold energies. Manageable plate heat fluxes (3-6 MW/m 2 ) are achieved by positioning the plate poloidal cross section at a minimum angle of 15-30/degree/ with respect to flux surfaces. 6 refs., 9 figs

Charged-particle thermonuclear reaction rates: IV. Comparison to previous work

International Nuclear Information System (INIS)

Iliadis, C.; Longland, R.; Champagne, A.E.; Coc, A.

2010-01-01

We compare our Monte Carlo reaction rates (see Paper II of this issue) to previous results that were obtained by using the classical method of computing thermonuclear reaction rates. For each reaction, the comparison is presented using two types of graphs: the first shows the change in reaction rate uncertainties, while the second displays our new results normalized to the previously recommended reaction rate. We find that the rates have changed significantly for almost all reactions considered here. The changes are caused by (i) our new Monte Carlo method of computing reaction rates (see Paper I of this issue), and (ii) newly available nuclear physics information (see Paper III of this issue).

2003 activity report of the development and research line in controlled thermonuclear fusion of the Plasma Associated Laboratory

International Nuclear Information System (INIS)

Ludwig, Gerson Otto

2004-01-01

This document represents the 2003 activity report of the development and research line in controlled thermonuclear fusion of the Plasma Associated Laboratory - Brazil, approaching the areas of toroidal systems for magnetic confinement, plasma heating, current generation and high temperature plasma diagnostic

Neutronic performance of a fusion-fission hybrid reactor designed for fuel enrichment for LWRs

International Nuclear Information System (INIS)

Yapici, H.; Baltacioglu, E.

1997-01-01

In this study, the breeding performance of a fission hybrid reactor was analyzed to provide fissile fuel for Light Water Reactors (LWR) as an alternative to the current methods of gas diffusion and gas centrifuge. LWR fuel rods containing UO 2 or ThO 2 fertile material were located in the fuel zone of the blanket and helium gas or Flibe (Li 2 BeF 4 ) fluid was used as coolant. As a result of the analysis, according to fusion driver (D,T and D,D) and the type of coolant the enrichment of 3%-4% were achieved for operation periods of 12 and 36 months in case of fuel rods containing UO 2 , respectively and for operation periods of 18 and 48 months in case of fuel rods containing ThO 2 , respectively. Depending on the type of fusion driver, coolant and fertile fuel, varying enrichments of between 3% and 8.9% were achieved during operation period of four years

Utilization of a pulsed D-T neutron generator

International Nuclear Information System (INIS)

Vilaithong, T.; Singkarat, S.; Tippawan, U.

2000-01-01

In the past two decades the IAEA has supported the establishment of neutron laboratories in many developing countries by providing small D-T neutron generators. The neutron generator is basically a low energy (100-400 keV) ion accelerator capable of producing a continuous beam of deuterons with a current in the range between 1-2.5 mA. These neutron generators are primarily intended to be used for fast neutron activation analysis. This paper describes the utilization of a 14 MeV neutron generator in continuous and pulsed beam modes in applied neutron physics program at Chiang Mai University. (author)

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

International Nuclear Information System (INIS)

Betti, R.; Zhou, C.

2005-01-01

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

Progress of fusion fuel processing system development at the Japan Atomic Energy Research Institute

International Nuclear Information System (INIS)

Nishi, Masataka; Yamanishi, Toshihiko; Kawamura, Yoshinori; Iwai, Yasunori; Isobe, Kanetsugu; O'Hira, Shigeru; Hayashi, Takumi; Nakamura, Hirofumi; Kobayashi, Kazuhiro; Suzuki, Takumi; Yamada, Masayuki; Konishi, Satoshi

2000-01-01

The Tritium Process Laboratory (TPL) at the Japan Atomic Energy Research Institute has been working on the development of fuel processing technology for fusion reactors as a major activity. A fusion fuel processing loop was installed and is being tested with tritium under reactor relevant conditions. The loop at the TPL consists of ZrCo based tritium storage beds, a plasma exhaust processing system using a palladium diffuser and an electrolytic reactor, cryogenic distillation columns for isotope separation, and analytical systems based on newly developed micro gas chromatographs and Raman Spectroscopy. Several extended demonstration campaigns were performed under realistic reactor conditions to test tritiated impurity processing. A sophisticated control technique of distillation column was performed at the same time, and integrated fuel circulation was successfully demonstrated. Major recent design work on the International Thermonuclear Experimental Reactor (ITER) tritium plant at the TPL is devoted to water detritiation based on liquid phase catalytic exchange for improved tritium removal from waste water

Operating large controlled thermonuclear fusion research facilities

International Nuclear Information System (INIS)

Gaudreau, M.P.J.; Tarrh, J.M.; Post, R.S.; Thomas, P.

1987-01-01

The MIT Tara Tandem Mirror is a large, state of the art controlled thermonuclear fusion research facility. Over the six years of its design, implementation, and operation, every effort was made to minimize cost and maximize performance by using the best and latest hardware, software, and scientific and operational techniques. After reviewing all major DOE fusion facilities, an independent DOE review committee concluded that the Tara operation was the most automated and efficient of all DOE facilities. This paper includes a review of the key elements of the Tara design, construction, operation, management, physics milestones, and funding that led to this success. The authors emphasize a chronological description of how the system evolved from the proposal stage to a mature device with an emphasis on the basic philosophies behind the implementation process. This description can serve both as a qualitative and quantitative database for future large experiment planning. It includes actual final costs and manpower spent as well as actual run and maintenance schedules, number of data shots, major system failures, etc. The paper concludes with recommendations for the next generation of facilities

High heat flux device of thermonuclear device

International Nuclear Information System (INIS)

Tachikawa, Nobuo.

1994-01-01

The present invention provides an equipments for high heat flux device (divertor) of a thermonuclear device, which absorbs thermal deformation during operation, has a high installation accuracy, and sufficiently withstands for thermal stresses. Namely, a heat sink member is joined to a structural base. Armour tiles are joined on the heat sink member. Cooling pipes are disposed between the heat sink member and the armour tiles. With such a constitution, the heat sink member using a highly heat conductive material having ductility, such as oxygen free copper, the cooling pipes using a material having excellent high temperature resistance and excellent elongation, such as aluminum-dispersed reinforced copper, and the armour tiles are completely joined on the structural base. Therefore, when thermal deformation tends to cause in the high heat flux device such as a divertor, cooling pipes cause no plastic deformation because of their high temperature resistance, but the heat sink member such as a oxygen free copper causes plastic deformation to absorb thermal deformation. As a result, the high heat flux device such as a divertor causes no deformation. (I.S.)

High performance with modified magnetic shear in JET DD and DT plasmas

International Nuclear Information System (INIS)

Gormezano, C.

1999-01-01

Internal transport barriers (ITBs) in which both the ion thermal diffusivity and electron thermal diffusivity are substantially reduced have been observed in JET. Such discharges have been obtained with DD and DT plasmas. Central ion temperatures of 40 keV and plasma pressure gradients of 10 6 Pa/m were observed in DT plasmas leading to a fusion triple product n i0 T i0 τ E 1.1 x 10 21 m -3 ·keV·s and producing 8.2 MW of fusion power. ITBs have been produced in both the MkII and the new Gas Box divertor configuration with similar behaviour. With the Gas Box divertor an L mode edge has so far only been produced using edge radiation cooling. For the first time, ITBs have been triggered by radiating about 40% of the power with a krypton puff. A possible scaling of the power needed to trigger an ITB with magnetic field is suggested. (author)

Design study of a fusion-driven tokamak hybrid reactor for fissile fuel production. Final report

International Nuclear Information System (INIS)

Rose, R.P.

1979-05-01

This study evaluated conceptual approaches for a tokamak fusion-driven fuel producing reactor. The conceptual design of this hybrid reactor was based on using projected state-of-the-art technology for the late 1980s. This reactor would be a demonstration plant and, therefore, first-of-a-kind considerations have been included. The conceptual definitions of two alternatives for the fusion driver were evaluated. A Two-Component Tokamak (TCT) concept, based on the TFTR plasma physics parameters, was compared to a Beam-Driven Thermonuclear (BDTN) concept, based on the USSR T-20 plasma physics parameters

Inertial confinement fusion

International Nuclear Information System (INIS)

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

1988-01-01

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

An analysis of the impact of the thermonuclear pilot project ITER on industry and research in Austria

International Nuclear Information System (INIS)

Hangel, G.

2007-03-01

An analysis of the influence of the thermonuclear pilot project ITER on Austrian research and industrial activities is presented in terms of the following subjects: fusion research history, ITER technique, security, nuclear fusion, ITER (reactor, project specifications for quotations), possibilities for Austrian companies and fusion research in Austria. (nevyjel)

Stability and Repeatability of the Distress Thermometer (DT and the Edmonton Symptom Assessment System-Revised (ESAS-r with Parents of Childhood Cancer Survivors.

Directory of Open Access Journals (Sweden)

Tatsiana Leclair

Full Text Available Parents report psychological distress in association with their child's cancer. Reliable tools are needed to screen parental distress over the cancer trajectory. This study aimed to estimate the stability and repeatability of the Distress Thermometer (DT and the Depression and Anxiety items of the Edmonton Symptom Assessment System-revised (ESAS-r-D; -A in parents of children diagnosed with cancer.Fifty parents (28 mothers, median age = 44 of clinically stable survivors of childhood solid and brain tumours completed questionnaires about their own distress (DT, ESAS-r-D; -A, Brief Symptom Inventory-18: BSI-18, Patient Health Questionnaire-9: PHQ-9, Generalized Anxiety Disorder-7: GAD-7 and their children's quality of life (QoL; Peds Quality of Life: PedsQL twice, with a month interval between the two assessments. At retest, parents also evaluated life events that occurred between the two time points. Hierarchical regressions explored moderators for the temporal stability of test measures.Stability estimates were ICC = .78 for the DT, .55 for the ESAS-r-D, and .47 for the ESAS-r-A. Caseness agreement between test and retest was substantial for the DT, fair for the ESAS-r-D, and slight for the ESAS-r-A. Repeatability analyses indicated that the error range for the DT was more than 2 pts below/above actual measurement, whereas it was more than 3 pts for the ESAS-r-A, and 2.5 for the ESAS-r-D. Instability of the DT could be explained by changes in children's physical QoL, but not by other components of QoL or life events. No moderators of stability could be identified for the ESAS-r items.The DT appears to be a fairly stable measure when the respondent's condition is stable yet with a relatively wide error range. Fluctuations in distress-related constructs may affect the temporal stability of the DT. The lower stability of ESAS-r items may result from shorter time-lapse instructions resulting in a greater sensitivity to change. Findings support

Integral experiment on molybdenum with DT neutrons at JAEA/FNS

Energy Technology Data Exchange (ETDEWEB)

Ohta, Masayuki, E-mail: ohta.masayuki@jaea.go.jp; Sato, Satoshi; Kwon, Saerom; Ochiai, Kentaro; Konno, Chikara

2016-11-01

Highlights: • An integral experiment on molybdenum was conducted with DT neutron at JAEA/FNS. • The experimental results were analyzed by MCNP5 with recent nuclear data libraries. • The calculated results generally show underestimation. • Problems on recent nuclear data of molybdenum were discussed. - Abstract: An integral experiment on molybdenum is performed with a DT neutron source at JAEA/FNS. A Mo assembly is covered with lithium oxide blocks in order to reduce background neutrons inside the assembly. Several reaction rates and fission rates are measured along the central axis inside the assembly and compared with calculated ones with the Monte Carlo transport code MCNP5-1.40 and recent nuclear data libraries of ENDF/B-VII.1, JENDL-4.0, and JEFF-3.2. The calculated results generally show underestimation. From our detailed analysis, it is concluded that the (n,2n) cross section data of all the Mo stable isotopes in JEFF-3.2 are more suitable than those in JENDL-4.0 and the (n,γ) cross section data of {sup 92}Mo, {sup 94}Mo, {sup 95}Mo, {sup 96}Mo, {sup 97}Mo, and {sup 100}Mo in JENDL-4.0 are overestimated.

Power source device for thermonuclear device

International Nuclear Information System (INIS)

Ozaki, Akira.

1992-01-01

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

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.)

Vacuum pumping for controlled thermonuclear reactors

International Nuclear Information System (INIS)

Watson, J.S.; Fisher, P.W.

1976-01-01

Thermonuclear reactors impose unique vacuum pumping problems involving very high pumping speeds, handling of hazardous materials (tritium), extreme cleanliness requirements, and quantitative recovery of pumped materials. Two principal pumping systems are required for a fusion reactor, a main vacuum system for evacuating the torus and a vacuum system for removing unaccelerated deuterium from neutral beam injectors. The first system must pump hydrogen isotopes and helium while the neutral beam system can operate by pumping only hydrogen isotopes (perhaps only deuterium). The most promising pumping techniques for both systems appear to be cryopumps, but different cryopumping techniques can be considered for each system. The main vacuum system will have to include cryosorption pumps cooled to 4.2 0 K to pump helium, but the unburned deuterium-tritium and other impurities could be pumped with cryocondensation panels (4.2 0 K) or cryosorption panels at higher temperatures. Since pumping speeds will be limited by conductance through the ducts and thermal shields, the pumping performance for both systems will be similar, and other factors such as refrigeration costs are likely to determine the choice. The vacuum pumping system for neutral beam injectors probably will not need to pump helium, and either condensation or higher temperature sorption pumps can be used

Thermonuclear burst oscillations: where firestorms meet fundamental physics.

CERN Multimedia

CERN. Geneva

2017-01-01

Neutron stars offer a unique environment in which to develop and test theories of the strong force. Densities in neutron star cores can reach up to ten times the density of a normal atomic nucleus, and the stabilising effect of gravitational confinement permits long-timescale weak interactions. This generates matter that is neutron-rich, and opens up the possibility of stable states of strange matter, something that can only exist in neutron stars. Strong force physics is encoded in the Equation of State (EOS), the pressure-density relation, which links to macroscopic observables such as mass M and radius R via the stellar structure equations. By measuring and inverting the M-R relation we can recover the EOS and diagnose the underlying dense matter physics. One very promising technique for simultaneous measurement of M and R exploits hotspots (burst oscillations) that form on the neutron star surface when material accreted from a companion star undergoes a thermonuclear explosion (a Type I X-ray burst). As ...

Magnet systems for the International Thermonuclear Experimental Reactor

International Nuclear Information System (INIS)

Henning, C.D.; Miller, J.R.

1988-01-01

The definition phase for the International Thermonuclear Experimental Reactor (ITER) has been nearly completed, thus beginning a three-year design effort by teams from the European Community (EC), Japan, US, and USSR. Preliminary parameters for the superconducting magnet system have been established to guide more detailed design work. Radiation tolerance of the superconductors and insulators has been important because it sets requirements for the neutron-shield dimension and sensitively influences reactor size. Major levels of mechanical stress appear in the structural cases of the inboard legs of the toroidal-field (TF) coils. The winding packs of the TF coils include significant fractions of steel that provide support against in-plane separating loads, but they offer little support against out-of-plane loads unless shear-bonding of the conductors can be maintained. Heat removal from nuclear and ac loads has not limited the fundamental design, but it has nonnegligible economic consequences. 3 refs., 3 figs., 5 tabs

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.)