[en] The use of the code NLIN (IBM Share Program No. 1428) to obtain empirical thermodynamic pressure-volume-temperature (P-V-T) relationships for substances in the gaseous and dense gaseous states is described. When sufficient experimental data exist, the code STATEQ will provide least-squares estimates for the 21 parameters of the Martin model. Another code, APPROX, is described which also obtains parameter estimates for the model by making use of the approximate generalized behavior of fluids. Use of the codes is illustrated in obtaining thermodynamic representations for isobutane

[en] There were 90 papers presented at the Conference in the category of Technology and Power Plants accounting for about 25% of the total number of contributions. As was the case at the previous meeting, a large number of papers dealt with the ITER-Engineering Design Activity (EDA) and ITER technology R and D. In the author's opinion, the rapid progress made during the ITER EDA extension on the completion of the new ITER-FEAT design and its physics and technology R and D validation stands out as the highlight of the meeting. Steady progress is being made on several other technology fronts as well. The results point towards emerging research trends in the following areas: steady-state operation with advanced performance and the increasingly important role of enabling technologies in achieving this goal, advanced, high-performance, environmentally attractive materials for the fusion energy goal, reactor and near-term applications studies that exploit advances both in the physics and technology fronts for lower cost of electricity and improved safety and environmental features, and socioeconomic studies that are helping to promote the attractive features of fusion and its public acceptance. The remaining sections of this paper are organized along the lines of these major themes; namely, ITER EDA Design, ITER Technology R and D, Progress Towards Advanced Performance and Steady State, Compact Cu Burning Plasma Experiments and Neutron Sources, Advanced Materials Research, Power Plant Design and Economic Forecasts, and Conclusions

[en] A method is presented for calculating the evaporation rate of hydrogenic pellets immersed in an unmagnetized plasma with a suprathermal particle component of arbitrary distribution function. The computational procedure is based on hydrodynamic solutions for the expansion of the gaseous cloud, obtained in a previous treatment that considered the effects of thermal particles only. The appropriate heat source terms, derived from the stopping power of the gaseous shield, are worked out for energetic ions produced by neutral beam injection heating. The model predicts 27-cm penetration in a Poloidal Divertor Experiment (PDX) plasma, compared with experimentally measured values in the range of 29 to 32 cm. An application to the Tokamak Fusion Test Reactor (TFTR) gives an estimated 21-cm penetration for a 2.5-mm-diam tritium pellet injection at 2000 m/s into a 55-cm-bore plasma heated to a central electron temperature of 4 keV by 34 MW of neutral injection

[en] High plasma densities have been produced in ohmic and neutral beam heated discharges on TFTR using a repeating pneumatic pellet injector developed at Oak Ridge National Laboratory (ORNL). Line average plasma densities as high as 1 x 10¹⁴ cm^-3 have been attained by injection of five 2.7 mm deuterium pellets (Δn/sub e/ = 2 x 10¹³ cm^-3) over a one-second interval into a stretched neutral beam pulse. Injection of a single large (4 mm) pellet in ohmic plasmas has produced highly peaked profiles with n/sub e/(o) = 1.8 x 10¹⁴ cm^-3, n/sub e/(o) tau/sub E/(a) = 6.7 x W10¹³ cm^-3 and n/sub D/(o)T/sub i/(o)tau/sub E/(a) = 8.8 x 10¹³ cm^-3 sKev. Global confinement in these discharges approaches 0.45 seconds with a central density decay time of 2 seconds. Based on a neoclassical resistivity model and x-ray pulse-height analysis, Z/sub eff/ is < 2 in both ohmic and beam-heated plasmas. The energy confinement properties of intermediate density (n/sub e/(o) = 1 x 10¹⁴ cm^-3) full beam power (5.7 MW, 80 KVD⁰) discharge have been studied in detail using the TRANSP code. The high density, pellet-fueled plasmas are contrasted with gas-fueled cases by a strongly inverted beam power deposition profile. Although the global energy confinement (∼ 200 ms at I/sub p/ = 2.2 MA) is comparable to gas-fueled discharges, the confinement in the central core is considerably longer and electron heat conduction loses are smaller

[en] Recent experiments on the Alcator-C, D-III, TFTR, and ASDEX tokamaks have demonstrated the importance of the plasma fueling mechanism on the performance of tokamak plasmas operating in the density regime of 5 x 10¹³-1 x 10¹⁵ cm^-3 and with plasma heating in the 2-8 MW range. Although the mechanism of edge fueling as embodied by gas injection and recycle has been generally understood for many years, its limitations have only recently been recognized. Pellet fueling presents an alternative to the broad plasma density profiles that result from edge heating in that the centrally peaked fuel deposition profiles lead naturally to more peaked density profiles, higher central densities, increased particle confinement times and reduced mantle densities and recycling. In many cases, the altered density profiles result in an increase in plasma stored energy and a concomitant increase in the gross energy confinement time, tau/sub E/

[en] A general overview of the fueling of magnetic confinement devices is presented, with particular emphasis on recent experimental results. Various practical fueling mechanisms are considered, such as cold gas inlet (or plasma edge fueling), neutral beam injection, and injection of high speed cryogenic hydrogen pellets. The central role played by charged particle transport and recycle of plasma particles from material surfaces in contact with the plasma is discussed briefly. The various aspects of hydrogen pellet injection are treated in detail, including applications to the production of high purity startup plasmas for stellarators and other devices, refueling of tokamak plasmas, pellet ablation theory, and the technology and performance characteristics of low and high speed pellet injectors

[en] S. Milora described the US programme on pellet injection. It has four parts: (1) a confinement experimental program; (2) pellet injector development; (3) theoretical support; and (4) tritium pellet study for TFTR

[en] Two-stage light guns are used extensively in hypervelocity research. The applications of this technology include impact studies and special materials development. Oak Ridge National Laboratory (ORNL) has developed two-stage guns that accelerate small projectiles (4-mm nominal diameter) to velocities of up to ∼5 km/s. These guns are relatively small and simple (thus, easy to operate), allowing a significant number of test shots to be carried out and data accumulated in a short time. Materials that have been used for projectiles include plastics, frozen isotopes of hydrogen, and lithium hydride. One gun has been used to demonstrate repetitive operation at a rate of 0.7 Hz; and, with a few design improvements, it appears capable of performing at firing frequencies of 1--2 Hz. A schematic of ORNL two-stage device is shown below. Unlike most such devices, no rupture disks are used. Instead, a fast valve (high-flow type) initiates the acceleration process in the first stage. Projectiles can be loaded into the gun breech via the slide mechanism; this action has been automated which allows repetitive firing. Alternatively, the device is equipped with ''pipe gun'' apparatus in which gas can be frozen in situ in the gun barrel to form the projectile. This equipment operates with high reliability and is well suited for small-scale testing at high velocity. 17 refs., 6 figs., 2 tabs

[en] This paper describes the development of pneumatic hydrogen pellet injectors for plasma fueling applications on the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET). The performance parameters of these injectors represent an extension of previous experience and include pellet sizes in the range 2-6 mm in diameter and speeds approaching 2 km/s. Design features and operating characteristics of these pneumatic injectors are presented

[en] The design and operation of the solid hydrogen pellet injection system used in plasma refueling experiments on the ISX tokamak are described. The gun-type injector operates on the principle of gas dynamic acceleration of cryogenic pellets confined laterally in a tube. The device is cooled by flowing liquid helium refrigerant, and pellets are formed in situ. Room temperature helium gas at moderate pressure is used as the propellant. The prototype device injected single hydrogen pellets into the tokamak discharge at a nominal 330 m/s. The tokamak plasma fuel content was observed to increase by 0.5 to 1.2 x 10¹⁹ particles subsequent to pellet injection. A simple modification to the existing design has extended the performance to 1000 m/s. At higher propellant operating pressures (28 bar), the muzzle velocity is 20% less than predicted by an idealized constant area expansion process