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Fuel cycle problems in fusion reactors

Description: Fuel cycle problems of fusion reactors evolve around the breeding, recovery, containment, and recycling of tritium. These processes are described, and their implications and alternatives are discussed. Technically, fuel cycle problems are solvable; economically, their feasibility is not yet known. (auth)
Date: January 13, 1976
Creator: Hickman, R.G.
Partner: UNT Libraries Government Documents Department

Secondary containment system for a high tritium research cryostat

Description: A 4.2- to 300-K liquid helium cryostat was constructed for cryogenic samples of D-T containing up to 4 x 10$sup 14$ dis/s (10,000 Ci) of tritium radioactivity. The cryostat is enclosed in a secondary box, which acts as the ultimate container in case of a tritium release. Dry argon is flushed through the box, and the box atmosphere is monitored for tritium, oxygen, and water vapor. A rupture disk and abort tank protect the box atmosphere in case the sample cell breaks. If tritium breaks into the box, a powdered uranium getter trap reduces the 4 x 10$sup 14$ dis/s (10,000 Ci) to 4 x 10$sup 9$ dis/s (0.1 Ci) in 24 h. A backup palladium-zeolite getter system goes into operation if an overabundance of oxygen contaminates the uranium getter. (auth)
Date: September 10, 1975
Creator: Tsugawa, R.T.; Fearon, D.; Souers, P.C.; Hickman, R.G. & Roberts, P.E.
Partner: UNT Libraries Government Documents Department

Two methods of space-time energy densification

Description: With a view to the goal of net energy production from a DT microexplosion, two ideas (methods) are studied through which (separately or in combination) energy may be ''concentrated'' into a small volume and short period of time--the so-called space-time energy densification or compression. The advantages and disadvantages of lasers and relativistic electron-beam (E-beam) machines as the sources of such energy are studied and the amplification of laser pulses as a key factor in energy compression is discussed. The pulse length of present relativistic E-beam machines is the most serious limitation of this pulsed-power source. The first energy-compression idea discussed is the reasonably efficient production of short-duration, high-current relativistic electron pulses by the self interruption and restrike of a current in a plasma pinch due to the rapid onset of strong turbulence. A 1-MJ plasma focus based on this method is nearing completion at this Laboratory. The second energy- compression idea is based on laser-pulse production through the parametric amplification of a self-similar or solitary wave pulse, for which analogs can be found in other wave processes. Specifically, the second energy-compression idea is a proposal for parametric amplification of a solitary, transverse magnetic pulse in a coaxial cavity with a Bennett dielectric rod as an inner coax. Amplifiers of this type can be driven by the pulsed power from a relativistic E- beam machine. If the end of the inner dielectric coax is made of LiDT or another fusionable material, the amplified pulse can directly drive a fusion reaction-- there would be no need to switch the pulse out of the system toward a remote target. (auth)
Date: July 15, 1975
Creator: Sahlin, H.L.
Partner: UNT Libraries Government Documents Department

Plasma focus as a pulsed power source

Description: The plasma focus is a remarkable natural phenomena that achieves significant space-time compression of both particle and field energy. Depending on the mode of operation, about 20 percent of the bank energy can be concentrated into the kinetic energy of a thin, dense, cylindrically convergent gas shell, or into a small-diameter, high-$nu$/$gamma$ relativistic electron burst and oppositely directed ion burst. The kinetic energy of the fast ions and electrons can exceed the applied voltage by a factor of greater than 100. The different modes of energy concentration by the plasma focus are presented and discussed both in terms of their role in the direct yield of the focus and for the case of a plasma focus supplemented by various fusionable targets. (auth)
Date: November 24, 1975
Creator: Sahlin, H.; McFarland, G.; Barlett, R. & Gullickson, R.
Partner: UNT Libraries Government Documents Department

Analysis of tritium releases to the atmosphere by a CTR

Description: Removal by atmospheric processes of routinely and accidentally released tritium from a controlled thermonuclear reactor (CTR) was investigated. Based on previous studies, the assumed form of the tritium for this analysis was HTO, or tritiated water vapor. Assuming a CTR operation in Morris, Illinois, surface water and ground-level air concentration values of tritium were computed for three space (or time) scales: local (50 Km of a plant), regional (up to 1000 Km of the plant), and global. (auth)
Date: October 1, 1975
Creator: Renne, D.S.; Sandusky, W.F. & Dana, M.T.
Partner: UNT Libraries Government Documents Department

Estimated D$sub 2$-DT-T$sub 2$ phase diagram in the three-phase region

Description: A composite of experimental eH$sub 2$-D$sub 2$ 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 are used to estimate the D$sub 2$-T$sub 2$, D$sub 2$-DT, and DT-T$sub 2$ binary phase diagrams. These are assembled into the ternary D$sub 2$-DT-T$sub 2$ 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 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. (auth)
Date: August 26, 1975
Creator: Souers, P.C.; Hickman, R.G. & Tsugawa, R.T.
Partner: UNT Libraries Government Documents Department

Ionization, charge exchange, and secondary electron emission in the extractor of an LBL/LLL neutral beam source

Description: Using a computer code, bombardment of the electrodes resulting from ionization, charge-exchange, and back-ion emission from the neutralizer cell is studied in the positive-ion extractor region of a Lawrence Berkeley Laboratory/ Lawrence Livermore Laboratory (LBL/LLL) neutral beam source. Ion and electron trajectories are presented, grid dissipations estimated, and proposals made for future designs. (auth)
Date: October 14, 1975
Creator: Fink, J.H. & McDowell, C.E.
Partner: UNT Libraries Government Documents Department

Computer control and monitoring of neutral beam injectors on the 2XIIB CTR experiment at LLL

Description: The original manual control system for the 12 neutral beam injectors on the 2XIIB Machine is being integrated with a computer control system. This, in turn, is a part of a multiple computer network comprised of the three computers which are involved in the operation and instrumentation of the 2XIIB experiment. The computer control system simplifies neutral beam operation and centralizes it to a single operating position. A special purpose console utilizes computer generated graphics and interactive function entry buttons to optimize the human/ machine interface. Through the facilities of the computer network, a high level control function will be implemented for the use of the experimenter in a remotely located experiment diagnositcs area. In addition to controlling the injectors in normal operation, the computer system provides automatic conditioning of the injectors, bringing rebuilt units back to full energy output with minimum loss of useful life. The computer system also provides detail archive data recording. (auth)
Date: November 18, 1975
Creator: Pollock, G.G.
Partner: UNT Libraries Government Documents Department

Test facility for the development of 150-keV, multi-megawatt neutral beam systems

Description: The next generation of CTR experiments, such as the Tokamak Fusion Test Reactor (TFTR), will require neutral-beam injection systems that produce multi- megawatt, 120-keV deuterium-beam pulses of 0.5-second duration. Since present injection systems are operating in the 10- to 40-keV range, an intensive development effort is in progress to meet a 150-keV requirement. The vacuum system and power supplies that make up a test facility to be used in the development of these injectors are described. (MOW)
Date: November 1, 1975
Creator: Haughian, W.; Baker, W.R.; Biagi, L.A. & Hopkins, D.B.
Partner: UNT Libraries Government Documents Department

Pellet trajectory correction

Description: The injection of frozen ammonia droplets in the Baseball II magnetic confinement system is discussed. Two ways to correct for random particle trajectories are described: (1) design non-turbulent orifices, and (2) design a trajectory correction system. (MOW)
Date: November 18, 1975
Creator: Bogdanoff, A.
Partner: UNT Libraries Government Documents Department

Intense negative hydrogen ion source for neutral injection into tokamaks

Description: In this scheme negative ions are extracted from a plasma source, accelerated to the required energy and then neutralized by stripping in a gas, metal vapor or plasma jet. One of the most promising direct extraction sources is the magnetron source, operating in the mixed hydrogen-cesium mode. In the present source cathode current densities are up to 20 A/cm$sup 2$ at arc voltages between 100 V and 150 V. In order to utilize the discharge more efficiently multislit extraction geometry was adopted. Highest currents were obtained by using six slits, with a total extraction area of 1.35 cm$sup 2$. At an extraction voltage of 18 kV negative hydrogen ion currents close to 1 A were obtained, which corresponds to current densities of about 0.7 A/cm$sup 2$ at the extraction aperture. Pulse length was 10-20 ms and the repetition rate 0.1 Hz. The total extracted current was usually 2-3 times the H$sup -$ current. (auth)
Date: January 1, 1975
Creator: Prelec, K. & Sluyters, T.
Partner: UNT Libraries Government Documents Department

Performance analysis of in-line direct converters for neutral beam sources

Description: The energetics of neutral beam formation from positive ion sources with beam direct conversion is presented. Two specific converters, the immersed grid and space charge controlled configurations, are described and their performance analyzed. The space charge controlled direct converter appears to be capable of high efficiency ion energy recovery at current density levels of interest in CTR applications. Experimental verification of the performance of this converter is underway. (auth)
Date: November 1, 1975
Creator: Bender, D.J.; Barr, W.L. & Moir, R.W.
Partner: UNT Libraries Government Documents Department