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A SUMMARY OF TEST OBSERVATIONS WHEN IBUTTONS ARE SUBJECTED TO RF ENERGY

Description: The iButton is a 'one-wire', temperature sensor and data logger in a short metal cylinder package 17 mm in diameter and 6 mm tall. The device is designed to be attached to a surface and acquire temperature samples over time periods as short as 1 second to as long as 300 minutes. Both 8-bit and 16-bit samples are available with 8kB of memory available. Lifetime is limited to an internal battery that cannot be replaced or recharged. The RF test interest originated with the concern that the data logger could inadvertently record electrical emanations from other nearby equipment. The normal operation of the data logger does not support high speed sampling but the control interface will operate at either 15.4 kbps or 125 kbps. There were no observable effects in the operation of the module or in the data that could be attributed to the use of RF energy. They made the assumption that these devices would potentially show RF sensitivity in any of the registers and in the data memory equally, therefore gross changes in the data might show RF susceptibility. No such sensitivity was observed. Because significant power levels were used for these tests they can extrapolate downward in power to state that no RF susceptibility would occur at lower power levels given the same configurations.
Date: October 26, 2011
Creator: Kane, R J & Baluyot, E V
Partner: UNT Libraries Government Documents Department

Electrical configuration for magnetic drift pumping on the tandem mirror experiment-upgrade (TMX-U)

Description: Magnetic drift pumping on TMX-U involves driving four antennae through high Q-resonant circuits. One of the key elements in the resonant circuit is a variable inductor able to carry the 3500 amperes through the circuit and maintain its shape and inductance. The eight resonant circuits can be combined to feed the four antennae with one or two frequencies on each antenna, or frequency shift keying between two frequencies. Each resonant circuit is fed by two 10 to 30 kHz exciters capable of delivering 80 kW each to the circuit. Each exciter receives its power from its own adjustable 0 to 400 volt power supply. The entire system is controlled by a CAMAC control system over a fiber-optic link. The control system checks interlock status, controls ''On'' and ''Off'' status, calculates and adjusts phasing of the exciters for addition or deletion of the proper beat frequencies, and monitors operation. 3 refs., 5 figs.
Date: November 11, 1985
Creator: Jackson, M.C.; Kane, R.J. & Hulsey, S.D.
Partner: UNT Libraries Government Documents Department

Applications of small computers for systems control on the Tandem Mirror Experiment-Upgrade

Description: Desktop computers operating into a CAMAC-based interface are used to control and monitor the operation of the various subsystems on the Tandem Mirror Experiment-Upgrade (TMX-U) at Lawrence Livermore National Laboratory (LLNL). These systems include: shot sequencer/master timing, neutral beam control (four consoles), magnet power system control, ion-cyclotron resonant heating (ICRH) control, thermocouple monitoring, getter system control, gas fueling system control, and electron-cyclotron resonant heating (ECRH) monitoring. Two additional computers are used to control the TMX-U neutral beam test stand and provide computer-aided repair/test and development of CAMAC modules. These machines are usually programmed in BASIC, but some codes have been interpreted into assembly language to increase speed. Details of the computer interfaces and system complexity are described as well as the evolution of the systems to their present states.
Date: November 29, 1983
Creator: Bork, R.G.; Kane, R.J. & Moore, T.L.
Partner: UNT Libraries Government Documents Department

Applications of digital processing for noise removal from plasma diagnostics

Description: The use of digital signal techniques for removal of noise components present in plasma diagnostic signals is discussed, particularly with reference to diamagnetic loop signals. These signals contain noise due to power supply ripple in addition to plasma characteristics. The application of noise canceling techniques, such as adaptive noise canceling and model-based estimation, will be discussed. The use of computer codes such as SIG is described. 19 refs., 5 figs.
Date: November 11, 1985
Creator: Kane, R.J.; Candy, J.V. & Casper, T.A.
Partner: UNT Libraries Government Documents Department

Neutral beam injector oxygen impurity measurements and concentration reduction via gettering processes. Revision 1

Description: We have measured the reduction of oxygen impurity levels by means of gettering within the arc chambers of the TMX-U neutral-beam injectors using the TMX-U neutral-beam test stand. Our analysis incorporated silicon surface-probe measurements and optical Doppler-shift measurements of the hydrogen alpha spectra of deuterium atoms with energies appropriate for D/sub 2/O parentage. Without gettering, the Auger electron spectroscopy analysis of an exposed silicon sample showed a large oxygen peak below the surface peak with a concentration equivalence of approximately 2% for an accelerated beam. After gettering, with either titanium or chromium getters, optical monochromator data indicated a reduction in the oxygen concentration of at least a factor of 10 whereas Auger spectroscopy data showed at least a factor-of-eight reduction. Other metallic impurities remained below the level of detection even after gettering. Additional effects observed during this study include a change in the accelerated deuterium species concentrations, loss of gettering activity, loss of arc operation, and a change in arc performance due to arc chamber gas absorption during operation.
Date: December 1, 1984
Creator: Kane, R.J.; Hsu, W.L.; Kerr, R.G.; Mills, B.E.; Poulsen, P. & Hibbs, S.
Partner: UNT Libraries Government Documents Department

Review of the Tandem Mirror Experiment-Upgrade (TMX-U) machine-parameter-instrumentation system

Description: The Tandem Mirror Experiment-Upgrade (TMX-U) machine consists of seven major machine subsystems: magnet system, neutral beam system, microwave heating (ECRH), ion heating (ICRH), gas fueling, stream guns, and vacuum system. Satisfactory performance of these subsystems is necessary to achieve the experimental objectives planned for TMX-U operations. Since the performance quality of the subsystem is important and can greatly affect plasma parameters, a 233-channel instrumentation system has been installed. Data from the instrumentation system are acquired and stored with the plasma diagnostic information. Thus, the details of the machine performance are available during post-shot analysis. This paper describes all the machine-parameter-instrumentation hardware, presents some typical data, and outlines how the data are used.
Date: November 15, 1983
Creator: Kane, R.J.; Coffield, F.E.; Coutts, G.W. & Hornady, R.S.
Partner: UNT Libraries Government Documents Department

TMX-Upgrade neutral-beam injection system

Description: The TMX experiment proved that axial confinement of central-cell ions is improved ninefold by the electrostatic potential of end-cell plasmas. The TMX Upgrade task is to improve this confinement further. This paper discusses the injector system aspects of the TMX Upgrade.
Date: October 5, 1981
Creator: Felker, B.; Kane, R.J.; Wong, R.L.; Calderon, M.O. & Moore, T.L.
Partner: UNT Libraries Government Documents Department

Organization and performance of the neutral beam system for the Tandem Mirror Experiment-Upgrade (TMX-U)

Description: The Tandem Mirror Experiment-Upgrade (TMX-U) at Lawrence Livermore National Laboratory (LLNL) uses 24 neutral-beam injectors to heat and fuel the experimental plasmas. This system is unique because TMX-U operates four times more injectors than any other fusion experiment. These injectors deliver an average of 50 A (accel) at 17 keV for 75 ms. Source conditioning time has been reduced to approximately four days for the entire system after extended machine air cycles. TMX-U is also unique because it has 35 usable injector assemblies for the 24 power systems. This quantity of injectors makes possible the development of new hardware and injector modifications, and the reconditioning of damaged sources without affecting machine operation. Efficient operation of a system of this size requires coordinated interaction between the injector service groups and the physics organization. We describe the current state of TMX-U performance and the aspects of group interaction essential to a project of this size.
Date: November 23, 1983
Creator: Kane, R.J.; Hibbs, S.M.; Kerr, R.G. & Poulsen, P.
Partner: UNT Libraries Government Documents Department

Tandem mirror experiment-upgrade neutral beam test stand: a powerful tool for development and quality assurance

Description: During construction of the Tandem Mirror Experiment-Upgrade (TMX-U), we assembled a test stand to develop electronics for the neutral beam system. In the first six months of test stand use we operated a few neutral beam injector modules and directed considerable effort toward improving the electronic system. As system development progressed, our focus turned toward improving the injector modules themselves. The test stand has proved to be the largest single contributor to the successful operation of neutral beams on TMX-U, primarily because it provides quality assurance andd development capability in conjunction with the scheduled activities of the main experiment. This support falls into five major categories: (1) electronics development, (2) operator training, (3) injector module testing and characterization, (4) injector module improvements, and (5) physics improvements (through areas affected by injector operation). Normal day-to-day operation of the test stand comes under the third category, testing and characterization, and comprises our final quality assurance activity for newly assembled or repaired modules before they are installed on TMX-U.
Date: December 2, 1983
Creator: Hibbs, S.M.; Kane, R.J.; Kerr, R.G. & Poulsen, P.
Partner: UNT Libraries Government Documents Department

Concepts and development of drift pumping for the Tandem Mirror Experiment-Upgrade (TMX-U)

Description: Low-energy ions trapped in the thermal barrier region of the TMX-U plasma cause a potential reduction which results in increased scattering and less thermal isolation between regions of the plasma. A method of removing these ions using magnetic field perturbations at the ion drift frequency has been developed. The concepts of ''drift pumping'' and hardware development are described in this paper. 5 refs., 7 figs.
Date: November 11, 1985
Creator: Kane, R.J.; Pedrotti, L.R.; Brooksby, C.A.; Cummins, W.F.; Jackson, M.C.; Poulsen, P. et al.
Partner: UNT Libraries Government Documents Department

Neutral beam injector oxygen impurity measurements and concentration reduction via gettering processes

Description: The reduction of oxygen impurity levels by means of gettering within the arc chambers of the TMX-U neutral beam injectors has been measured. The TMX-U Neutral Beam Test Stand was used for this experiment. Analysis incorporated silicon surface probes and optical Doppler-shift measurements of the Lyman alpha spectra of deuterium atoms with energies appropriate for D/sub 2/O parentage. Without gettering, the Auger electron spectroscopy analysis of an exposed silicon sample showed a large oxygen peak below the surface peak with a concentration equivalent of approximately 2% for an accelerated beam. After gettering, with either titanium or chromium getters, the oxygen concentration was reduced by at least a factor of 10 according to optical monochromator data, and at least a factor of 8 from Auger spectroscopy data. Simultaneously, other metallic impurities were not increased substantially as a result of gettering. Additional effects observed during this study include a change in the accelerated deuterium species concentrations, loss of gettering activity and arc operation, and a change in arc performance from arc chamber gas absorption during operation.
Date: October 1, 1984
Creator: Kane, R.J.; Hsu, W.L.; Kerr, R.G.; Mills, B.E.; Poulsen, P. & Hibbs, S.
Partner: UNT Libraries Government Documents Department