[en] The small-caliber electrothermal plasma gun SIRENS has been used to accelerate mini-projectiles to demonstrate the feasibility of using such guns as a pellet injector for fueling of future fusion reactors. The gun has been modified to accommodate acceleration of plastic projectiles to simulate frozen hydrogenic pellets required to fuel fusion reactors. Barrel sections are equipped with diagnostics for velocity and position of the projectile. The length of the acceleration path could be varied between 15 and 45 cm. The pulse forming network (PFN) can provide up to 100 kJ discharge energy over 0.1 to 1.0 ms pulse duration. The projectile velocities have been measured via a set of break wires. The ODIN code has been modified to account for the projectile mass, acceleration and friction. Plasma parameters compared to code results are discussed in detail

[en] The current concept of fueling large fusion devices is based on gas puffing and pellet injection. The pellet injector produces, accelerates and transports into a plasmas the pellets composed of hydrogen isotopes. Here, tasks and design of a tritium repeating pellet injector developed in Russia are presented. The injector uses improved in-situ and extrusion technologies for pellet formation

[en] An innovative device for producing a double-layer pellet is designed, constructed and operated for the purposes: (1) efficient fueling of a specific species such as tritium in the plasma core region, (2) controlled deposition of specific minority ions in the plasma core region for efficient ICRF heating, (3) establishment of an accurate transport diagnostic system to measure particle transport both parallel and perpendicular to the magnetic field lines of magnetic confinement devices. For the precise set-up of the cryohead, special techniques have been used, and the whole device has been successfully constructed. It has been shown that the positioning accuracy under cooling with liquid helium is about 10 μm. The production of a pellet having a void has been proved with a photograph of the ejected pellet taken by a fast flash lamp during flight

[en] A method is proposed for investigating the processes in the combustion chamber of chemical heat engines. In this method, the processes in the combustion chamber and the fuel injector are considered.

[en] New repetitive multibarrel pellet injector for steady-state fueling and diagnostics purposes in large fusion devices has been designed. The injector is intended to apply in the Large Helical Device at the National Institute for Fusion Science in Japan. The steady-state operation is provided by ten pipe-guns with unique porous units forming solid hydrogen pellets for 5 - 9 s in every barrel. Over one thousand hydrogen pellets have been formed and accelerated to 1.2 km/s at the different repetitive rates. The injector design and experimental results are presented. (author)

[en] In this communication, we present the work executed in a rapid compression machine to determine the swirl flow pattern created in a cylindrical chamber for which the gaz intake is tangential. This volume disposition is representative of the combustion chamber 'COMET' or 'KOUCHOUL'. (author)

[en] Gas atomization is one of the methods for production of clean metal powders at relatively moderate cost. A laboratory scale gas atomizer was designed and fabricated indigenously to produce metal powders with a batch capacity of 500 g of copper (Cu). The design includes several features regarding fabrication and operation to provide optimum conditions for atomization. The inner diameter of atomizing chamber is 440 mm and its height is 1200 mm. The atomizing nozzle is of annular confined convergent type with an angle of 25 degree. Argon gas at desired pressure has been used for atomizing the metals to produce relatively clean powders. A provision has also been made to view the atomization process. The indigenous laboratory scale gas atomizer was used to produce tin (Sn) and copper (Cu) powders with different atomizing gas pressures ranging from 2 to 10 bar. The particle size of different powders produced ranges from 40 to 400 im. (author)

[en] The research for gas-filling technology under control was carried out for cryogenic target with fill-tube, based on temperature gradient between the fuel reservoir and target cell. The effect of temperature gradient on fuel filling processes with different size targets was studied by theoretical calculation and experiment. The results show that the influence on the initial fill pressure difference is slight with respect to different final temperatures for fuel reservoir. In other words, it is suitable for gas-filling process for target with any diameter under control by temperature gradient. One can note that the fuel injectivity is more accuracy for the wide range temperature gradient as the temperature difference reduction for fuel liquefying, with the target diameter expansion. The sensitivity within ±3 μm/K for the reservoir at the operation temperature of 75 K is quite adequate for layer thickness control purposes, with regard to the target at the diameter of 2 mm and the fuel reservoir at the volume of 1.6 mL. These results could afford an important foundation for highly accuracy of fuel injectivity of cryogenic target. (authors)

[en] As basis of the particle fueling methods of fusion plasma by pellet injection, the pellet fueling technologies, and deposition of pellet particles in consideration of pellet ablation in the high temperature plasma and drift of plasmoid by the E x B drift model developed by P.B. Parks are explained. The distribution of pellet particles in ITER was evaluated by using the pellet particle deposition code with consideration for E x B drift. The results showed that particles were able to be fueled until about ρ=0.5, although the pellet was ablated outer side of ρ=0.9 by pellet injection from the high magnetic field. The pellet production methods; in-situ method and extruder method, the pellet acceleration methods and the solid hydrogen pellet fueling are stated. (S.Y.)

[en] Since ice used for forming solid hydrogen isotopes, for use in a fuel supply pellet injection device of a thermonuclear reactor or the like has been cooled, solidified and then extruded as ice filaments or cylindrical ice pellets, it can not be formed continuously in any case and can not be supplied efficiently to high temperature plasmas kept by intense magnetic fields. Then, a rotatable screw shaft for continuously extruding fluids from a supply side to a discharge side and a cooling device for cooling the fluids during the extrusion and solidifying them into ice are disposed to an ice forming extrusion mechanism. The fluids having the temperature and the pressure controlled by coolants and a heater are supplied to the inlet of the rotating screw shaft and extruded continuously, while they are cooled by the cooling device and solidified from a slimy to an icy state gradually. Ice can be generated continuously and supplied efficiently to high temperature plasmas kept by intense magnetic fields. (N.H.)