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Project planning and management techniques of the fast-paced TMX-Upgrade construction

Description: The Tandem Mirror Experiment-Upgrade (TMX-Upgrade) construction will be completed in 18 months at a total cost of $14.5 million. This paper describes the project planning and the management techniques used to complete the TMX-Upgrade within its allocated cost and schedule. In the planning stages of a project, before approval of the proposal, we define major project objectives, create a work breakdown structure (WBS), detail a technical description for each level of the WBS, and provide detailed bottoms-up cost estimates and summary schedules. In the operating phase, which continues throughout the project, we establish budget and schedule baselines. The reporting phase includes The Department of Energy (DOE) reviews of project status at monthly, quarterly, and semiannual intervals. These reports include cost, schedule, manpower, major procurement, and technical status information.
Date: October 26, 1981
Creator: Seberger, C.D. & Chargin, A.K.
Partner: UNT Libraries Government Documents Department

Drift waves in rotating plasmas

Description: The stability of the electron drift wave is investigated in the presence of E x B plasma rotation typical of the central cell plasma in tandem mirrors. It is shown that a rotationally-driven drift wave may occur at low azimuthal mode numbers. Conditions for rotational instabilities are derived. Quasilinear formulas are given for the anomalous transport associated with the unstable fluctuations.
Date: September 1, 1983
Creator: Horton, W. & Liu, J.
Partner: UNT Libraries Government Documents Department

Improved system for perpendicular electron-cyclotron emission measurements on TMX-Upgrade

Description: Perpendicular electron-cyclotron emission (PECE) is used on TMX-U to diagnose thermal-barrier hot electrons (T/sub H/ approx. 100 to 400 keV); yielding the time history of the temperature of these relativistic electrons. We describe an improved quasi-optical viewing system for these measurements that uses high sensitivity superheterodyne receivers at fixed frequencies of 60, 98, 130, and 196 GHz. The improved viewing and transport system consists of an off-axis ellipsoidal mirror that images the plasma onto a V-band conical collection horn, an overmoded circular waveguide (7/8'' diam) that transports the radiation outside the vacuum vessel where the polarization is selected, and a high absorptivity Macor beam dump to prevent internal wall reflections from entering the viewing system. A relativistic code is used to calculate optically thin PECE signals from relativistic electrons for various energy and pitch angle distributions. 4 refs., 4 figs.
Date: March 7, 1986
Creator: Lasnier, C.J.; Ellis, R.F. & James, R.A.
Partner: UNT Libraries Government Documents Department

Recent beam probe measurements on EBT, TMX, and RENTOR

Description: It is noted that beam probe systems can provide accurate, reliable measurments of plasma space potential and nf(T/sub e/). Over some temperature range, at least, it should be possible to separate n and T/sub e/ by measuring the multiple ionization reaction products. It is also an ideal diagnostic for studying fluctuations since it provides a simultaneous measurement of phi and nf(T/sub e/) from the same point in the plasma and the measurements are continuous in time. Measurements can be made quasi-continuously in space by rapidly sweeping the beam. By using more than one detector it should be possible to make measurements simultaneously at two different observation points in the plasma.
Date: June 1, 1980
Creator: Hickok, R. L.
Partner: UNT Libraries Government Documents Department

Engineering design of a 40 kV neutral-beam source

Description: Sections of the 40-kV, 40-A, TMX source are shown. This module is comprised of the arc chamber and accelerator sections. The source accelerator section uses a single rectangular insulator to perform three functions: providing voltage standoff, forming the supporting structure, and acting as the vacuum wall. Both machinable glass ceramic (Corning Macor/sup TM/) and F.R.P. (Nema G-10) have been used for this insulater. In either case, the insulator is joined to the titanium base plate and extractor electrode by thermal-setting-epoxy adhesive. The parts are self jigging; the bonding is done at 120 to 130 /sup 0/C under a load of .34 MPa (50 psi).
Date: November 5, 1979
Creator: Duffy, T.J.; Molvik, A.W.; Baird, E.D.; Correll, D.L.; Munger, R.H.; Gillespie, K. et al.
Partner: UNT Libraries Government Documents Department

Using perpendicular electron-cyclotron emission to diagnose the thermal barrier electrons in TMX-Upgrade. Progress report

Description: Possibilities are explored for diagnosing the hot-electron distribution function for the thermal barriers of tandem mirrors using perpendicular electron-cyclotron emission. Emission from a relativistic bimaxwellian with a loss cone is calculated in the single-particle limit. Formulae are derived for finding T/sub perpendicular/ for a bimaxwellian by measuring frequencies of the harmonic intensity maxima at optically thin frequencies, or the intensity at optically thick frequencies. A positive par. delta f/par. delta p/sub perpendicular/ in the distribution function is shown to lead to decreased absorption, and instability for low T/sub perpendicular/. Methods are discussed for diagnosing the loss-cone distribution by comparing numerical calculation with measured intensity ratios and frequencies at the harmonic peaks. Finally, the perpendicular source function in the single-particle limit for this distribution function is calculated.
Date: January 1, 1983
Creator: Celata, C.M.
Partner: UNT Libraries Government Documents Department

Analysis of x-ray production in TMX upgrade

Description: TMX Upgrade (TMX-U), a tandem mirror experiment at LLNL, will use high power microwaves for electron cyclotron resonant heating (ECRH). As demonstrated on Elmo Bumpy Torus (EBT) and related experiments which use similar heating techniques, high energy electron populations are created. In these devices, which run CW, significant x-ray production occurs and adequate shielding must be provided for personnel protection. TMX-U is a pulsed experiment; however, significant x-ray production is expected from the 50 keV mean energy electron population. In this report the expected x-ray generation is calculated and the provisions for shielding are described. Based upon these calculations, as well as scaling estimates from other devices, the provided shielding is shown to be adequate for hot electron temperatures of interest for the experiment.
Date: February 4, 1982
Creator: Stallard, B. & Stephens, L.
Partner: UNT Libraries Government Documents Department

Technician support for operation and maintenance of large fusion experiments: the tandem mirror experiment upgrade (TMX-U) approach

Description: As experiments continue to grow in size and complexity, a few technicians will no longer be able to maintain and operate the complete experiment. Specialization is becoming the norm. Subsystems are becoming very large and complex, requiring a great deal of experience and training for technicians to become qualified maintenance/operation personnel. Formal in-house and off-site programs supplement on-the-job training to fulfill the qualification criteria. This paper presents the Tandem Mirror Experiment-Upgrade (TMX-U) approach to manpower staffing, some problems encountered, possible improvements, and safety considerations for the successful operation of a large experimental facility.
Date: December 1, 1983
Creator: Mattson, G.E.
Partner: UNT Libraries Government Documents Department

Transient plasma estimation: a noise cancelling/identification approach

Description: The application of a noise cancelling technique to extract energy storage information from sensors occurring during fusion reactor experiments on the Tandem Mirror Experiment-Upgrade (TMX-U) at the Lawrence Livermore National Laboratory (LLNL) is examined. We show how this technique can be used to decrease the uncertainty in the corresponding sensor measurements used for diagnostics in both real-time and post-experimental environments. We analyze the performance of algorithm on the sensor data and discuss the various tradeoffs. The algorithm suggested is designed using SIG, an interactive signal processing package developed at LLNL.
Date: March 1, 1985
Creator: Candy, J.V.; Casper, T. & Kane, R.
Partner: UNT Libraries Government Documents Department

Gyrokinetic equilibrium and stability in quadrupole tandem mirrors

Description: This paper discusses recent theoretical work on the equilibrium and stability of quadrupole tandem mirrors in the paraxial limit. It reviews calculations of three-dimensional equilibria by means of a ..beta..-expansion technique which lead to an understanding of the important role played by parallel currents and the corollary importance of careful design of the structure of the vacuum geodesic curvature. The previously predicted scaling with central-cell length of the finite-..beta.. distortion of vacuum flux surfaces is shown to saturate because of finite orbit effects. An adaptation to tandem geometries of the reduced MHD technique for calculating high-..beta.. three-dimensional equilibria is described. This approach uses the paraxial expansion to resolve the time-dependent relaxation to equilibrium into three distinct timescales on which the motion can be followed independently. Regarding stability, it is shown that kinetic effects suppress ballooning modes of short-to-moderate perpendicular wavelength; in the limit that such effects are dominant only rigid modes are possible. The stability of the latter modes is investigated within the context of the energy principle. Results of equilibrium and stability calculations for the TMX-U and MFTF-B experiments at Livermore are presented.
Date: August 2, 1982
Creator: Bulmer, R.H.; Kaiser, T.B.; Nevins, W.M.; Newcomb, W.A.; Pearlstein, L.D.; Strauss, H.R. et al.
Partner: UNT Libraries Government Documents Department

Nature and effects of ion-cyclotron fluctuations in TMX

Description: In the tandem mirror experiment (TMX), coherent oscillations have been identified as resulting from the Alfven ion-cyclotron instability. Although the drive for this instability is localized in the end cell, the waves generated propagate out of the unstable region and interact with the central-cell ions. This interaction leads to an experimentally observed scaling of the stored end-cell energy with axial ion end-loss current.
Date: February 19, 1982
Creator: Casper, T.A.; Poulsen, P. & Smith, G.R.
Partner: UNT Libraries Government Documents Department

Results and analysis of the TMX electron-beam injection experiments

Description: Electron beams (e-beams) were injected into the Tandem Mirror Experiment (TMX) plasma in order to investigate the effect on the ion cyclotron fluctuations of the plasma. The power level of the e-beams was comparable to that of the injected neutral beams. It was found that injection of the e-beams produced no significant effect on the ion cyclotron fluctuations, the measured plasma parameters, or the particle and power flow of the plasma. The increase in bulk electron temperature and the production of mirror-confined electrons found in previous experiments in which e-beams were injected into a mirror-confined plasma were not observed in this experiment. Analysis of the regions and frequencies of wave creation and absorption within the plasma shows that the plasma density and magnetic field profiles through the plasma strongly affect the resonances encountered by the waves. The steep axial density profiles produced by neutral-beam injection in the TMX experiment are not conducive to efficient coupling of the e-beam energy to the plasma.
Date: August 1, 1980
Creator: Poulsen, P. & Grubb, D.P.
Partner: UNT Libraries Government Documents Department

Results of TMX operations: January-July 1980

Description: This interim report summarizes results from the Tandem Mirror Experiment (TMX) during the period January to July 1980 and describes the physics experiments, the machine operation, and the diagnostics that were added to TMX during this period. This operating period followed the initial proof-of-principle TMX experiments and predated the ongoing final experiments preceding TMX shutdown for modification to TMX Upgrade. The results described in this report include measurements of plasma parameters and plasma behavior which confirm the initial TMX results that demonstrated that the tandem mirror configuration can be generated and sustained by neutral beam injection and that the tandem mirror configuration improves confinement of magnetic mirror systems.
Date: September 25, 1980
Creator: Correll, D.L. & Drake, R.P. (eds.)
Partner: UNT Libraries Government Documents Department

Model for ion confinement in a hot-electron tandem mirror anchor

Description: Anisotropic, hot electrons trapped in local minimum-B wells have been proposed as MHD-stabilizing anchors to an otherwise axisymmetric tandem configuration. This work describes a model for plasma confinement between the anchors and the remainder of the system and calcuates the power loss implied by maintenance of this plasma.
Date: September 30, 1980
Creator: Baldwin, D.E.
Partner: UNT Libraries Government Documents Department

Mechanical design for TMX injector system

Description: The injector system for the Tandem Mirror Experiment (TMX) contains the components required to create and maintain a high-temperature, high-density plasma. These components include a streaming-plasma gun in each of the plug tanks to form the target-plasma, 24 neutral-beam source modules for injecting neutral deuterium atoms to heat and replace losses from the plasma, and a gas box system that applies a streaming cold gas to the plasma to stabilize it. This paper discusses the mechanical design problems and solutions for this injector system.
Date: October 17, 1977
Creator: Calderon, M.O.; Chen, F.F.K. & Denhoy, B.S.
Partner: UNT Libraries Government Documents Department

Design for the magnetic field requirements of the tandem mirror experiment

Description: The tandem mirror magnetic geometry is described, followed by an analysis of the magnet set designed to meet the requirements of the TMX experiment. The final magnet line-up is composed of a baseball coil with two C coils for each plug, six solenoidal coils for the central cell, and two RC coils plus one octupole coil for each transition.
Date: October 10, 1977
Creator: Chen, F.K.; Chargin, A.K.; Denhoy, B.S. & Waugh, A.F.
Partner: UNT Libraries Government Documents Department

Introduction to magnetic confinement fusion diagnostics

Description: These notes present a brief survey of some of the current diagnostic techniques used in magnetic fusion plasma devices. To give an idea of the range of parameters and geometries encountered the parameters of four representative experiments - PLT, TMX, ZT-40 and EBT-I(S) - are given. The central issue of all experiments is to understand the flow of power which can be summarized by two volume integrated equations for the ions and electrons.
Date: June 6, 1980
Creator: Turner, W.C.
Partner: UNT Libraries Government Documents Department

Neutron yield measurements on a TMX endplug

Description: Neutron yield measurements were made on the east endplug of TMX using a calibrated recoil proton counter. The detector consists of a liquid scintillator (NE 213) with a pulse shape discrimination property that allows for identifying photon and neutron interactions. An energy threshold is established to suppress the response to scattered neutrons with energies lower than 1 to 2 MeV. Results indicate there are typical neutron yields of 2 to 3 x 10/sup 11/ n/s during a 25-ms discharge with 200 A of 20-keV neutral beam injection into the endplug.
Date: March 17, 1980
Creator: Slaughter, D.R.
Partner: UNT Libraries Government Documents Department

Small-scale experimental tests of tandem mirror machines with thermal barriers

Description: A summary is given of current physical understanding of tandem mirrors with thermal barriers. Physicists who understand tandem mirrors can use this document as a preliminary guide to the physical issues and experimental problems involved. This report will focus upon the issues that can be tested experimentally, and on the areas needing experimental and theoretical inventions. The next section discusses the plasma potentials and plasma confinement which correspond to a tandem mirror with thermal barriers, assuming the barriers exist in steady-state. The creation of a barrier is discussed, i.e., the natural tendency of the barrier cell to fill with plasma must be countered by pumping ions out of the barrier. The design of a barrier-pumping experiment for TMX is described.
Date: September 1, 1979
Creator: Drake, R.P.
Partner: UNT Libraries Government Documents Department

Application of power-factor correction in the Tandem Mirror Experiment Upgrade magnet power supply

Description: The magnet power supply for the Tandem Mirror Experiment Upgrade (TMX Upgrade) contains 24 groups of dc rectifiers that feed the water-cooled magnets. Each group consists of five or less rectifiers, connected in series. All 24 are current-regulating, using phase-controlled bilateral thyristors in the rectifier transformer primaries. The electric utility system must furnish reactive power to these phase-controlled thyristors as well as to the cmmutating diodes in the rectifier bridges.
Date: August 14, 1981
Creator: Corvin, W.C.
Partner: UNT Libraries Government Documents Department

Database tools for enhanced analysis of TMX-U data. Revision 1

Description: A commercial database software package has been used to create several databases and tools that assist and enhance the ability of experimental physicists to analyze data from the Tandem Mirror Experiment-Upgrade (TMX-U) experiment. This software runs on a DEC-20 computer in M-Division's User Service Center at Lawrence Livermore National Laboratory (LLNL), where data can be analyzed offline from the main TMX-U acquisition computers. When combined with interactive data analysis programs, these tools provide the capability to do batch-style processing or interactive data analysis on the computers in the USC or the supercomputers of the National Magnetic Fusion Energy Computer Center (NMFECC) in addition to the normal processing done by the TMX-U acquisition system. One database tool provides highly reduced data for searching and correlation analysis of several diagnostic signals within a single shot or over many shots. A second database tool provides retrieval and storage of unreduced data for use in detailed analysis of one or more diagnostic signals. We will show how these database tools form the core of an evolving offline data analysis environment on the USC computers.
Date: March 6, 1986
Creator: Stewart, M.E.; Carter, M.R.; Casper, T.A.; Meyer, W.H.; Perkins, D.E. & Whitney, D.M.
Partner: UNT Libraries Government Documents Department

Control of gas input and background pressure in the end plug regions of the TMX-U thermal barrier experiment

Description: Rate equations for the plasma species in a thermal barrier end plug establish an upper bound on the neutral pressure (P) external to the plasma. For the Tandem Mirror Experiment-Upgrade (TMX-U), this bound is P less than or equal to 0.5 - 1.0 x 10/sup -6/ Torr. Initially TMX-U did not satisfy this criterion, and axial end plugging of plasma losses seemed limited by the excessive pressure. Subsequently, we modified the machine to improve the vacuum conditions, decreasing P to the desired range. At the same time axial end plugging of plasma losses increased to the duration of neutral beam injection and ECRH heating. Here we summarize our experimental measurements of gas input.
Date: October 26, 1983
Creator: Turner, W.C.; Nexsen, W.E.; Allen, S.L.; Hooper, E.B.; Hunt, A.L.; Lang, D.D. et al.
Partner: UNT Libraries Government Documents Department