[en] We have examined the dominant mechanisms of energy flow in a fusion-fission hybrid reactor, which is based on a magnetically confined thermonuclear D-T plasma. D-T fusion provides a source of high energy neutrons which are absorbed in a blanket outside the reactor. The blanket combines the functions of energy multiplication by fission of U²³⁸, Pu²³⁹ and U²³³, and tritium breeding. The fusion driver produces 100 MW of neutron power while the blanket provides energy multiplication of about 50. The hybrid can produce about 2000 MW of electrical power. The plasma is contained in the space between two concentric cylinders. There is uniformity in the direction parallel to the curved surfaces of the cylinders, and the confining field is purely toroidal. The plasma has a rectangular cross-section bounded by a planar electrode at one end and a thermionic emitter at the other, and cylindrical walls inside and outside. There is a modest pressure gradient, i.e., nT ∼ constant. The temperature is high in the core of the plasma, where fusion occurs, but falls to low values near the walls and end-plates. He has have found a class of sustainable MHD equilibria with Q ∼ 0.3. The inner and outer radii and height of the reactor are 31, 38 and 7 metres respectively. A high magnetic field is required, in the range 200-400 kG. T rises from 200 eV at the walls to 2.7 keV in the fusion zone, where n, ∼ 1.5 x 10¹⁴ cm^-3. There is a small vertical flow velocity to provide fueling. He has studied alpha-particle slowing down, electron-cyclotron radiation transport, inelastic reactions, bremsstrahlung, conduction, convection, and heat exchange between electrons and ions in the reactor

[en] Rock fracturing using electrically produced shocks in water is emerging as an environment-friendly substitute for fracturing by explosives. This involves producing underwater pressure waves or shocks of the desired intensity in a water-filled cavity drilled in the rock. We have numerically studied different options in an attempt to minimize the electrical energy consumption in this process, given a desired final pressure in the cavity. The first option is to follow different thermodynamic paths, e.g., isentropic and single shock, from the initial to the final pressure of water. It is found that isentropic compression allows a reduction of 2 - 3 times in energy input as compared to compression by a single shock. The second option is to replace water by other fluids. It has been found that the use of aqueous solutions at high electrolyte concentrations can reduce the energy consumption by over 30%. [copyright] 2001 American Institute of Physics

[en] Wigner distributions for quantum mechanical systems whose configuration space is a finite group of odd order are defined so that they correctly reproduce the marginals and have desirable transformation properties under left and right translations. While for the Abelian case we recover known results, though from a different perspective, for the non-Abelian case our results appear to be new

No abstract available

[en] The important mechanisms of energy flow in a quasi-isobaric magnetic fusion device have been studied in a three-part paper. In Part I, the spatial profiles of plasma parameters that yield acceptable values of Q_dt and plasma dimensions, were determined. These profiles were determined by balancing the dominant terms in the differential energy equations, i.e., conduction, bremsstrahlung, and collisional energy exchange, against each other. One class of equilibria was identified for a more detailed study. In Part II, the contributions of inelastic processes, radiation transport and alpha-particle heating were studied. These terms, in combination with the dominant terms studied earlier, yield the spatial profile of external heating that is required to balance the energy equations everywhere in the plasma. In Part III, the results of ray-tracing calculations for waves in the lower hybrid range are reported. These calculations show that it is possible to produce such a deposition profile for both electrons and ions, if the launch structure can couple the required k spectrum through the high-density edge plasma. 12 refs., 10 figs., 1 tab

No abstract available

[en] In this paper unusual probabilities of absorption and emission of quons by an atomic medium are reported. The deviations from the usual atomic transition probabilities can be used as an evidence for quons if they were to exist and were to interact with matter

[en] The dominant mechanics of energy flow in a novel magnetic confinement device have been examined. The plasma is contained in the space between two concentric cylinders. There is uniformity in the direction parallel to the curved surfaces of the cylinders, i.e., the toroidal direction, and the confining magnetic field is purely toroidal. The plasma has a rectangular cross section, bounded by a planar electrode at one end and a thermionic emitter at the other, and cylindrical walls inside and outside. There is a modest pressure gradient, i.e., NT ≅ constant. The temperature is high in the core of the plasma, where fusion occurs, but falls to low values near the walls and end-plates. It is hoped that the quasi-isobaric character will eliminate or reduce serious instabilities and that plasma behavior will be near classical. The high-N, low-T periphery should reduce damage to the walls from energetic plasma particles. The contributions of alpha-particle slowing down, electron cyclotron radiation transport, atomic processes, bremsstrahlung, conduction, convection, and heat exchange between electrons and ions to the energy balance in the plasma have been evaluated. Radio-frequency heating using waves in the lower hybrid range can balance the differential energy equations for electrons and ions throughout the plasma. For a device producing 125 MW of fusion power, there is a class of magnetohydrodynamic equilibria that is energetically sustainable, with Q_dt ≅ 0.3. The inner and outer radii and height of the reactor are 31.4, 38.7, and 7.3 m, respectively. A high magnetic field is required, in the range of 20 to 40 T. The temperature T rises from 200 eV near the walls to 2.7 keV in the fusion core, where N_c ≅ 1.5 x 10¹⁴ cm^-3. This device may be acceptable as the fusion driver of a fusion-fission hybrid reactor. 18 refs., 12 figs., 3 tabs

[en] The important mechanisms of energy flow in a quasi-isobaric magnetic fusion device are studied. In Part I of this paper, the spatial profiles of plasma parameters that yield acceptable values of Q_dt and plasma dimensions are determined. These profiles are determined by balancing the dominant terms in the differential energy equations, i.e., conduction, bremsstrahlung, and collisional energy exchange, against each other. One class of equilibria was identified for a more detailed study. In Part II, the contributions of inelastic processes, radiation transport, and alpha-particle slowing down to the differential energy balances for electrons and ions are examined. Bremsstrahlung loss is found to be the dominant term for electrons. Inelastic processes involving hydrogen are important for ions in the fusion open-quotes core.close quotes Impurity radiation can be important even with a low impurity content. Energy deposition by alpha particles is significant in the high-density edge, while cyclotron radiation transport plays some role in regions with large density gradients. 14 refs., 9 figs

[en] The Poloidal Field (PF) coil system in a tokamak must be optimized, taking into account the desired flexibility in plasma equilibria, and practical constraints on the number of coils, their locations and dimensions. Such optimization requires the generation of a large number of magetohydrodynamics (MHD) equilibria spanning the desired equilibrium space. Given the large parameter space, it is necessary to use a fast method for determining the PF coil system required for a given plasma equilibrium. In this work, an inverse Grad-Shafranov solver is coupled with a PF coil current optimizer which incorporates various design constraints. The method can handle shaped tokamak plasma equilibria with a divertor configuration. This method is found to be considerably faster than conventional free-boundary codes, and the calculated PF coil currents are in reasonable agreement with those from free-boundary solutions. This method has been applied to PF optimization of SST-1 for maximizing the operational envelope