Engineering prototypes for theta-pinch devices
Hansborough, L.D.; Hammer, C.F.; Hanks, K.W.; McDonald, T.E.; Nunnally, W.C.
1975-01-01
Past, present, and future engineering prototypes for theta-pinch plasma-physics devices at Los Alamos Scientific Laboratory are discussed. Engineering prototypes are designed to test and evaluate all components under system conditions expected on actual plasma-physics experimental devices. The importance of engineering prototype development increases as the size and complexity of the plasma-physics device increases. Past experiences with the Scyllac prototype and the Staged Theta-Pinch prototype are discussed and evaluated. The design of the proposed Staged Scyllac prototype and the Large Staged Scyllac implosion prototype assembly are discussed
Numerical studies of the linear theta pinch
Brackbill, J.U.; Menzel, M.T.; Barnes, D.C.
1975-01-01
Aspects of several physical problems associated with linear theta pinches were studied using recently developed numerical methods for the solution of the nonlinear equations for time-dependent magnetohydrodynamic flow in two- and three-dimensions. The problems studied include the propagation of end-loss produced rarefaction waves, the flow produced in a proposed injection experiment geometry, and the linear growth and nonlinear saturation of instabilities in rotating plasmas, all in linear geometries. The studies illustrate how numerical computations aid in flow visualization, and how the small amplitude behavior and nonlinear fate of plasmas in unstable equilibria can be connected through the numerical solution of the dynamical equations. (auth)
Material testing in a linear theta pinch
Alani, R.; Azodi, H.; Naraghi, M.; Safaii, B.; Torabi-Fard, A.
1983-01-01
The interaction of stainless steel 316 and Inconel 625 alloys has been investigated with a thermonuclear-like plasma, n = 10 16 cm -3 and Tsub(i) = 1 keV, generated in the Alvand I linear theta pinch. The average power flux is 10 7 W/cm 2 and the interaction time nearly one μs. A theoretical analysis based on the formation of an observed impurity layer near the material, has been used to determine the properties of the impurity layer and the extent of the damage on the material. Although arcing has been observed, the dominant damage mechanism has been assessed to be due to evaporation. Exposure to single shots has produced very heavily defective areas and even surface cracks on the SS 316 sample, but no cracks were observed on Inconel 625 after exposure to even 18 shots. On the basis of temperature rise and evaporation a comparison is made among materials exposed to plasmas of a theta pinch, shock tube, present generation tokamak and an anticipated tokamak reactor. (orig.)
Rotational instability in a linear theta pinch
Ekdahl, C.; Bartsch, R.R.; Commisso, R.J.; Gribble, R.F.; McKenna, K.F.; Miller, G.; Siemon, R.E.
1980-01-01
The m=1 ''wobble'' instability of the plasma column in a 5-m linear theta pinch has been studied using an axial array of orthogonally viewing position detectors to resolve the wavelength and frequency of the column motion. The experimental results are compared with recent theoretical predictions that include finite Larmor orbit effects. The frequency and wavelength characteristics at saturation agree with the predicted dispersion relation for a plasma rotating faster than the diamagnetic drift speed. Measurements of the magnetic fields at the ends of the pinch establish the existence of currents flowing in such a way that they short out the radial electric fields in the plasma column. The magnitude of rotation, the observed delay in the onset of m=1 motion, and the magnitude of end-shorting currents can all be understood in terms of the torsional Alfven waves that communicate to the central plasma column the information that the ends have been shorted. The same waves are responsible for the torque which rotates the plasma and leads to the observed m=1 instability. Observations of the plasma in the presence of solid end plugs indicate a stabilization of high-m number modes and a reduction of the m=1 amplitude
LTPF: a linear theta-pinch neutron source
Ellis, W.R.
1975-07-01
The linear theta pinch is optimized with respect to maximum neutron current on a sample located between the discharge tube and the compression coil wall. Emphasis throughout is placed on physics and technology considerations which govern the choice of parameters. Technological demands are (hopefully) kept to a minimum. Two ''point designs'' are developed which are distinguished by their compressional magnetic field (i.e., coil current) wave-forms: one is sinusoidal and continuous, the other trapezoidal and pulsed intermittently. Both point designs give an average neutron current of approximately 5 x 10 13 n/cm 2 /s. Both devices are characterized by short lengths (approximately 1 m), rapid cycling (2 to 30 kHz), and magnetic mirrors (2 to 5:1) at the ends. A crucial item is the power supply, which is discussed in detail. (U.S.)
Recent developments in linear theta-pinch research: experiment and theory
McKenna, K.F.; Bartsch, R.R.; Commisso, R.J.
1978-01-01
High energy plasmas offusion interest can be generated in linear theta pinches. However, end losses present a fundamental limitation on the plasma containment time. This paper discusses recent progress in end-loss and end-stoppering experiments and in the theoretical understanding of linear theta-pinch physics
Kinetic description of linear theta-pinch equilibria
Batchelor, D.B.; Davidson, R.C.
1975-01-01
Equilibrium properties of linear theta-pinch plasmas are studied within the framework of the steady-state (o/x=0) Vlasov-Maxwell equations. The analysis is carried out for an infinitely long plasma column aligned parallel to an externally applied axial magnetic field Bsub(z)sup(ext)esub(z). Equilibrium properties are calculated for the class of rigid-rotor Vlasov equilibria, in which the th component distribution function (Hsub(perpendicular), Psub(theta), upsilonsub(z) depends on perpendicular energy H and canonical angular momentum Psub(theta), exclusively through the linear combination Hsub(perpendicular)-ωsub(j)Psub(theta), where ω;=const.=angular velocity of mean rotation. General equilibrium relations that pertain to the entire class of rigid-rotor Vlasov equilibria are discussed; and specific examples of sharp- and diffuse-boundary equilibrium configurations are considered. Rigid-rotor density and magnetic field profiles are compared with experimentally observed profiles. A general prescription is given for determining the functional dependence of the equilibrium distribution function on Hsub(perpendicular)-ωsub(j)Psub(theta) in circumstances, where the density profile or magnetic field profile is specified. (author)
Field-reversed configuration produced by a linear theta-pinch, Tupa-1
Kayama, M.E.; Boeckelmann, H.K.; Sakanaka, P.H.; Machida, M.
1987-01-01
The formation of field reversed configuration, FRC, in one meter mirrorless linear theta-pinch device Tupa-I was observed. This configuration was studied during the first half magnetic cycle of ringing main bank discharge using magnetic probes. The separatrix radius by the exclude flux probe and the ion temperature by visible spectroscopy were measured. The plasma dynamics was observed by the image converter camera. A clear indication of the formation of FRC due to reconnection of the antiparallel bias to the main field and a fast reconnection, less than 0.2 microsec, that is explained in terms of forced reconnection driven by the Kruskal-Schwarzschild instability, are also observed. (author) [pt
Engineering and physics considerations for a linear theta-pinch hybrid reactor (LTPHR)
Krakowski, R.A.; Miller, R.L.; Hagenson, R.L.
1976-01-01
A fusion-fission hybrid reactor based on pulsed, high-β, linear theta-pinch magnetic confinement is considered. A preliminary design which incorporates key physics, engineering and economic considerations is presented. An extensive presentation of the system energy balance is made, and this energy balance is evaluated parametrically. The feasibility of end-loss reduction is addressed
Experimental study of the initial plasma formation stage in a linear theta pinch of inverted field
Casin, G.C.; Alvarez, Ricardo; Rojkind, R.H.; Rodrigo, A.B.
1986-01-01
The initial stage of the plasma formation was studied in a linear theta pinch. Experiments were made to determine the machine operating conditions for good shot-to-shot reproducibility. Spectroscopic measurements of electron density and of electron and ion temperature were made afterwards to characterize the plasma at different stages of its heating process. The results obtained indicate that shot-to-shot reproducibility is strongly influenced by the presence of impurities and by the plasma preionization technique used. Under proper operating conditions, excellent reproducibility was observed. The measured values of the plasma parameters are compatible with those determined for similar machines. (Author) [es
Bailey, A.G.; Chandler, G.I.; Ekdahl, C.A. Jr.; Lillberg, J.W.; Machalek, M.D.; Seibel, F.T.
1976-01-01
Scylla IV-P is a flexible, linear theta pinch designed to investigate high-density linear concepts, end-stoppering, alternate heating methods, and plasma injection techniques relevant to a pure fusion reactor and/or a fusion-fission hybrid system. The construction and experimental arrangement of the device are briefly described
Energy storage and transfer with homopolar machine for a linear theta-pinch hybrid reactor
Vogel, H.F.; Brennan, M.; Dase, W.G.; Tolk, K.M.; Weldon, W.F.
1976-01-01
The energy storage and transfer system for the compression coils of a linear theta-pinch hybrid reactor (LTPHR) are described. High efficiency and low cost are the principal requirements for the energy storage and transfer of 25MJ/m or 25GJ for a 1-km LTPHR. The circuit efficiency must be approximately 90%, and the cost for the circuit 5-6c/J. Scaling laws and simple relationships between circuit efficiency and cost-per-unit energy as a function of the half cycle time are presented. An important consideration concerns the pulse repetition rate of 2.25 pulses per second, 70x10 6 shots/yr, or 1.7x10 9 shots over the 25-yr plant life. Current interruption to initiate energy transfer is not feasible at this rate. Therefore, a simple ringing circuit with contactors to make and break at the periodically occurring zero-current instances, is considered
Energy storage and transfer with homopolar machine for a linear theta-pinch hybrid reactor
Vogel, H.F.; Brennan, M.; Dase, W.G.; Tolk, K.M.; Weldon, W.F.
1975-12-01
This report describes the energy storage and transfer system for the compression coil system of a linear theta-pinch hybrid reactor (LTPHR). High efficiency and low cost are the principal requirements for the energy storage and transfer of 25 MJ/m or 25 GJ for a 1-km LTPHR. The circuit efficiency must be approximately 90 percent, and the cost for the circuit 5 to 6 cents/J. Scaling laws and simple relationships between circuit efficiency and cost per unit energy as a function of the half cycle time are presented. Capacitors and homopolor machines are considered as energy storage elements with both functioning basically as capacitors. The advantage of the homopolar machine in this application is its relatively low cost, whereas that of capacitors is better efficiency
York, T.M.; Klevans, E.H.
1977-02-01
Experimental and analytical studies initiating and supporting research on flow and energy losses at the ends of a linear theta pinch have been carried out. A 25 cm linear pinch coil has been driven by a 515,000 A discharge with 10 μsec half-cycle time supplied by a 100 μF, 18 kV energy storage system. With reliable preionization generated up to 400 mT He, current sheath behavior has been identified with magnetic loop probes and double loop probes. Spectroscopic determination of preionization has been made. A ruby laser Thomson scattering diagnostic has been designed and is being procured. A study of transient plasma behavior in a 10 cm theta pinch has been carried out with a Twyman-Green interferometer using a 7 mW He--Ne CW laser. Pressure, electric field, and velocity probe diagnostics have received preliminary testing. Design work has been completed for the doubling of pinch length and energy storage system. Studies of particle loss scaling and reactor scaling of linear theta pinch devices have been reported. Detailed calculations of plasma properties at the end of the pinch coil following expansion from the central coil have been carried out. A O--D, time dependent computer code that includes conduction, convection, and magnetic field diffusion has been developed. Predicted plasma behavior is in good agreement with experimental data
Structural design aspects of magnetic coils for a linear theta-pinch hybrid reactor
Bartholomew, R.J.
1976-02-01
The structural design aspects of a linear theta-pinch hybrid reactor (LTPHR) are centered in the solenoidal adiabatic compression coil (ACC) which must support the high magnetic pulse forces that tend to expand the coil and separate the leads. The structural model is represented by the theory of elasticity solution to a thick-walled cylinder. Dynamic amplification (or attenuation) is considered by a shock spectrum technique. A composite material is postulated, where the conductor material for each strand is clad with a high-strength stainless steel with insulation considered. Yield strength (for isolated-pulse operation) and endurance limit (for repetitive-pulse operation) for the high-strength steel impose magnetic field strength constraints on the coil design. These constraints are combined in an overall energy balance calculation that includes neutronic considerations to determine an optimum ACC design. The computer code ENBAL was used to incorporate neutronic, electrical, and structural constraints into the overall energy balance of the LTPHR. The lead separation problem is solved by designing spaced clamps to hold the leads together over great distances
Energy- and particle-confinement properties of an end-plugged, linear, theta pinch
Commisso, R.J.; Bartsch, R.R.; Ekdahl, C.A.; McKenna, K.F.; Siemon, R.E.
1979-01-01
Experiments show that axial confinement of plasma in a straight theta-pinch solenoid is improved by placing solid lithium deuteride plugs at the ends. The energy confinement is increased nearly threefold in agreement with theoretical estimates which assume classical electron thermal conduction and no convective losses. The confinement of deuterium ions is explained by classical Coulomb collisions in the ablated lithium deuteride plasma
Plasma resistivity in a slow rising current theta-pinch device
Kayama, Milton Eiji; Dobrowolsky, Marcelo Shubert; Honda, Roberto Yzumi; Aramaki, Emilia Akemi; Algatti, Mauricio Antonio
1998-01-01
Anomalous behavior of plasma resistivity was observed in a Theta-pinch plasma. A comparative analysis was performed with a hybrid numerical code where the Chodura s resistivity algorithm is included. Good agreement was found in the radial plasma dynamic description. The experimental value of resistivity at null field point was found to be one order of magnitude greater than the theoretical prediction. (author)
York, T.M.; Klevans, E.H.
1979-02-01
Experimental and analytical studies of end loss from a linear theta pinch have been carried out. Analysis of reduced data on loss from a 25 cm long theta pinch has indicated: rotation at the end of pinch collapse, which appears to persist; ejection of the plasma in two modes, the first of which includes reversed, trapped fields; unique patterns of radial and axial variation of electron density in the end loss flow; substantial inaccuracies in plasma properties indicated by spectroscopy as compared to Thomson scattering. Studies of loss in a 50 cm long pinch with 50 eV, 2 x 10 16 cm -3 plasma are underway
Linford, R.K.; Downing, J.N.; Gribble, R.F.; Jacobson, A.R.; Platts, D.A.; Thomas, K.S.
1975-01-01
The Staged Theta Pinch program is designed to study the technological and physics problems associated with producing fat plasmas and separating the implosion heating from the adiabatic compression. Several methods of implosion heating are discussed. Circuit diagrams and theoretical magnetic field behavior are described for the STP and resonant heating experiments. (MOW)
York, T.M.; Klevans, E.H.
1980-05-01
Experimental and analytical studies of particle and energy loss at the ends of a linear theta pinch have been carried out. A study of transients occurring in the formation of reversed trapped fields within the coil, and of transients in the end region of a 25 cm long device was completed. A 1-D code has proven to be highly accurate in describing loss events and defining transport mechanisms in different experiments and is described here. A study of loss along field lines in a 50 cm long device has generated new information on loss velocity, axial and radial temperature gradients, and has established an initial effort in understanding thermal loss to the walls. Rotation and parallel trapped fields have been added to the existing 0-D code. A new technique crowbar switch and magnetic field prediction code have been developed. Direct measurment of electron velocity with Thomson scattering was accomplished experimentally. A Nd-glass laser system, frequency doubled, is being developed for low density diagnostics. Theoretical results that accurately predict confinement in FRX devices are described
A reversed-field theta-pinch plasma machine
Yasojima, Yoshiyuki; Ueda, Yoshihiro; Sasao, Hiroyuki; Ueno, Noboru; Tanaka, Toshihide
1984-01-01
Mitsubishi Electric has constructed a reversed-field theta-pinch machine at its Central Research Laboratory and initiated a series of plasma diagnostics and control studies for development of nuclear-fusion technology. Although the device has a linear configuration, a stable high-temperature, high-density toroidal plasma can be generated. The article describes the overall structure, vacuum system, power-supply system, and diagnostics and control system of the plasma machine. (author)
Staged theta pinch experiments
Linford, R.K.; Downing, J.N.; Gribble, R.F.; Jacobson, A.R.; Platts, D.A.; Thomas, K.S.
1976-01-01
Two implosion heating circuits are being experimentally tested. The principal experiment in the program is the 4.5-m-long Staged Theta Pinch (STP). It uses two relatively low energy (50kJ and 100 kJ), high voltage (125 kV) capacitor banks to produce the theta pinch plasma inside the 20 cm i.d. quartz discharge tube. A lower voltage (50 kV), higher energy (750 kJ) capacitor bank is used to contain the plasma and provide a variable amount of adiabatic compression. Because the experiment produces a higher ratio of implosion heating to compressional heating than conventional theta pinches, it should be capable of producing high temperature plasmas with a much larger ratio of plasma radius to discharge tube radius than has been possible in the past. The Resonant Heating Experiment (RHX) in its initial configuration is the same as a 0.9-m-long section of the high voltage part of the STP experiment and all the plasma results here were obtained with the experiment in that configuration. Part of the implosion bank will be removed and a low inductance crowbar added to convert it to the resonant heating configuration. (U.K.)
Jacoby, B.A.
1981-01-01
The results of an experimental study of particle and thermal loss processes from a 50-cm long theta pinch are presented. The plasma was generated with a 40-mTorr fill of deuterium in a 3.81 cm radius discharge tube; 67% Z-preionization was followed by a main current discharge that produced a 23-kG peak magnetic field in 4.75 μsec. The electron density and temperature in the plasma column at the end of dynamic implosion were characterized by 1.0 x 10 16 cm -3 and 20 eV, respectively. This was followed by adiabatic compression which occurred with the particle and energy loss of interest. The diagnostics employed in this experiment were Thomson scattering, continuum radiation spectroscopy, local magnetic-field probes, local pressure probes, and diamagnetic loops. Axial temperature and density profiles were mapped from the coil into the end region
York, T.M.; Klevans, E.H.
1978-02-01
Experimental and analytical studies of end loss from a theta pinch have been carried out. Detailed diagnostic studies of a 25 cm long theta pinch operating with reversed trapped fields have been completed; spectroscopic studies, magnetic probe, pressure probe, double diamagnetic loop, luminosity studies and Thomson scattering studies of the plasma have been carried out over the 8 μsec duration of the transient loss. Two new diagnostic techniques have been developed based on the available Thomson scattering laser source. A study of plasma loss from a 10.5 long theta pinch with an axial Twyman-Green interferometer has been completed and reported. The basic studies needed for subsequent experimental work on heat conduction loss being diagnosed by Thomson scattering data in the end region, with and without mirror coil, has been completed as a part of the mirror field studies
Vacuum ultraviolet emission from argon, krypton, and xenon in a radial-viewed theta pinch
Engleman, R. Jr.; Thomson, D.B.; Monaghan, D.A.
1976-03-01
Vacuum ultraviolet line emission from argon, krypton, and xenon (5 percent in deuterium) has been observed from a plasma (approximately 50 eV and N/sub e/ approximately 10 17 /cm 3 ) produced by the Scyllar linear theta-pinch device. More than 50 emission lines in the 30- to 500-A region have been measured for each gas mixture. Some lines have been identified as due to Ar VII through XI, Kr IX and X, and Xe IX, but many lines remain unassigned
Field reversed theta pinch TC-I UNICAMP
Honda, R.Y.; Machida, M.; Aramaki, E.A.; Porto, P.; Berni, L.A.
1990-01-01
Field reversed configuration TC-I device is 16 cm diameter, 1 meter long with two mirror coils and 30 kJ field reversed theta pinch working for over two years at University of Campinas. Its implosion dynamics and field reversal parameters have been studied using flux excluded loops, internal magnetic probe, visible spectroscopy, photodiode array and image converter camera. The vacuum vessel is a pyrex tube of 14,5 cm diameter pumped with a liquid nitrogen cooled diffusion pump to a base pressure of 6 x 10 -7 Torr. The schematic view of the machine and experimental set up are shown. (Author)
A spectroscopic study of radiation produced in a theta-pinch
Trigueiros, A.; Machida, M.; Pagan, C.J.B.
1988-01-01
Preliminary results of the analysis of the spectra of four times ionized Krypton, Kr-V, are presented. 28 transitions were classified and for five of then the classification is new. We also present the UNICAMP theta-pinch for the study of highly ionized atoms. This device is now in testing. (author) [pt
Studies of end loss from a theta pinch using a Twyman--Green interferometer. Scientific report 77-4
Freeman, R.S.
1977-11-01
The transient rate of flow of plasma from the ends of a short, high density, low temperature linear theta pinch was studied experimentally and analytically. Diagnostic devices were used to study the discharge and plasma properties; these included a Rogowski coil, a magnetic field probe and a Twyman-Green double pass interferometer which was illuminated by a 7 mW He--He laser. The interferometer was used to monitor the passage of fringes with respect to time at two radial positions simultaneously by the use of a photodetector consisting of two fast silicon photodiodes with supporting circuitry. One complete fringe represented a change in number density of 2.942 x 10 16 cm -3
Simplified scaling model for the THETA-pinch
Ewing, K. J.; Thomson, D. B.
1982-02-01
A simple ID scaing model for the fast Theta pinch was developed and written as a code that would be flexible, inexpensive in computer time, and readily available for use with the Los Alamos explosive-driven high magnetic field program. The simplified model uses three successive separate stages: (1) a snowplow-like radial implosion, (2) an idealized resistive annihilation of reverse bias field, and (3) an adiabatic compression stage of a Beta = 1 plasma for which ideal pressure balance is assumed to hold. The code uses one adjustable fitting constant whose value was first determined by comparison with results from the Los Alamos Scylla III, Scyllacita, and Scylla IA Theta pinches.
Energy transfer efficiency measurements in a theta-pinch
Cavalcanti, G.H.; Luna, F.R.T.; Trigueiros, A.G.
1993-01-01
An increase in energy transfer efficiency of the capacitor bank to the plasma was obtained when the electrical system of a theta-pinch was changed so that the ratio of total inductance to coil inductance was switched of 1/6 to 1/2. A further increase about 20% was obtained for 16/1 ratio. The measurements were made through the current discharge decay, and the spectral analysis of the emitted light from theta-pinch shows a correspondent efficiency increase. (author)
Investigation of plasma turbulence in a theta-pinch-discharge
Lins, G.
1980-01-01
This thesis is concerned with investigations of plasma turbulence in a 3 KJ Theta-Pinch during implosion by high-frequency Stark-effect and Thomson scattering. The next points are modifications of electron-distribution function by ionization in low preionizized turbulent plasma and energy losses by particle flow and heat flow at the ends. (HT)
Instability study during implosion in the Tupa Theta-Pinch
Kayama, M.E.; Boeckelmann, H.K.
1986-01-01
The importance of instabilities which occur during plasma heating in a Theta Pinch, in the implosion phase, is analysed. The plasma diagnostic was done by ultrafast photography and diamagnetic probe. The implosion time and the current layer thickness were calculated using a hybrid code for plasma simulation. The theoretical data were compared with the experimental ones. (M.C.K.) [pt
Steady state theta pinch concept for slow formation of FRC
Hirano, K.
1987-05-01
A steady state high beta plasma flow through a channel along the magnetic field increasing downstream can be regarded as a ''steady state theta pinch'', because if we see the plasma riding on the flow we should observe very similar process taking place in a theta pinch. Anticipating to produce an FRC without using very high voltage technics such as the ones required in a conventional theta pinch, we have studied after the analogy a ''steady state reversed field theta pinch'' which is brought about by steady head-on collision of counter plasma streams along the channel as ejected from two identical co-axial plasma sources mounted at the both ends of the apparatus. The ideal Poisson and shock adiabatic flow models are employed for the analysis of the steady colliding process. It is demonstrated that an FRC involving large numbers of particles is produced only by the weak shock mode which is achieved in case energetic plasma flow is decelerated almost to be stagnated through Poisson adiabatic process before the streams are collided. (author)
Electrical insulators for the theta-pinch fusion reactor
Clinard, F.W. Jr.
1976-01-01
The five major applications for electrical insulators in the Reference Theta Pinch Reactor are as follows: (1) first-wall insulator, (2) blanket intersegment insulator, (3) graphite encapsulating insulator, (4) implosion coil insulator, and (5) compression coil insulator. Insulator design proposals and some preliminary test results are given for each application
Velocity-space particle loss in field-reversed theta pinches
Hsiao, M.Y.
1983-01-01
A field-reversed theta pinch (FRTP) is a compact device for magnetic fusion. It has attracted much attention in recent years since encouraging experimental results have been obtained. However, the definite causes for the observed particle loss rate and plasma rotation are not well known. In this work, we study the velocity-space particle loss (VSPL), i.e., particle loss due to the existence of a loss region in velocity space, in FRTP's in order to have a better understanding about the characteristics of this device
Belitz, R. J.; Bogen, P.; Dippel, K. H.; Jordan, H. L.; Kugler, E.; Miyahara, A.; Noll, P.; Schlueter, J.; Witulski, H. [Association EURATOM-Kernforschungsanlage, Juelich (Germany)
1966-04-15
Experiments on the behaviour of the magnetic compression of preheated hydrogen plasmas in theta pinches of linear and spindle-cusped geometries have been made with the following devices: 1) 5kJ linear theta pinch, coil diameter 4.5 cm, length 15 cm, B{sub max} = 50 kGT{sub Vulgar-Fraction-One-Half} = 1.5 {mu}sec; 2) 600-kJ linear theta pinch, coil diameter 10.5 cm, length 128 cm, B{sub max} = 100 kG, T{sub Vulgar-Fraction-One-Half} = 17 {mu}sec; 3) 10-kJ spindle' cusped theta with B{sub max} = 45 kG at point and line cusps, radius 5.2 cm, length 8.5 cm. They all have provisions for preionization by. a capacitively-coupled low-power RF transmitter, magnetic bias field of variable strength and polarity, preheating by pulsed oscillating electrodeless ring discharge, and compression of the plasma by a fast capacitor bank. Observations have been made by using smear and framing camera photography, optical interferometry with Mach-Zehnder and differential interferometers, spectroscopy in the visible and the soft X-ray regions, and magnetic probes. These methods give information on plasma structure, on density profiles, on the distribution of electron and ion-Doppler temperatures and their development in time. Both stable and unstable plasmas were observed in linear devices. By variation of pressure, bias field, preionization, preheating, and impurity concentration, and by disturbing the symmetry of the discharge tube, information on stable and unstable parameter regions could be obtained. Deviations from the symmetry of 1 the plasma column can occur because of: (1) drifts connected with spatial inhomogeneities of the confining magnetic field; (2) axial motions and contractions in plasmas with trapped antiparallel fields, and rarefaction waves due to end losses; (3) rotations, and deformation oscillations of the cross-section of the plasma; and (4) star-shaped instabilities and eruptions. While drifts and axial motions are directly connected with magnetic field
Torus C-I field reversed theta-pinch at UNICAMP
Machida, M.; Collares, M.P.; Honda, R.Y.; Sakanaka, P.H.; Scheid, V.H.B.
1984-01-01
The influence of multipole fields (octopole and quadrupole) on supressing the n=2 rotational instability, field reconnection, particle loss effects is studied, and the viability of transforming the theta-pinch from Campinas, Brazil (100Kv, 55Kj) to the field reversed theta-pinch with plasma translation program is analyzed. (E.G.) [pt
Compact-Toroid Fusion Reactor (CTOR) based on the Field-Reversed Theta Pinch
Hagenson, R.L.; Krakowski, R.A.
1981-01-01
Scoping studies of a translating Compact Torus Reactor (CTOR) have been made on the basis of a dynamic plasma model and an overall systems approach. This CTOR embodiment uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plamoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conducting shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radition shielding. On the basis of this batch-burn but thermally steady-state approach, a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15
Compact-Toroid fusion reactor based on the field-reversed theta pinch
Hagenson, R.L.; Krakowski, R.A.
1981-03-01
Early scoping studies based on approximate, analytic models have been extended on the basis of a dynamic plasma model and an overall systems approach to examine a Compact Toroid (CTOR) reactor embodiment that uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plasmoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conducting shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radiation shielding. On the basis of this batch-burn but thermally steady-state approach, a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15
Cost estimation for a theta-pinch reactor
Coultas, T.A.; Cook, J.M.; Crnkovich, P.; Dauzvardis, P.
1976-02-01
A simulation of a theta-pinch fusion power plant has been completed to the point where economic feasibility can be examined. A PL/I cost subprogram is presented for interfacing with the computer code TPFPP. This code is then used to obtain a first approximation of the costs for the reactor. Independent geometrical and plant design parameters are varied over a wide range, with simultaneous variation of magnetic field, minor first wall radius, and plasma maximum compression. The study indicates that the plant energy balance must be favorable, availability must be high, and major component costs must be low to achieve economical results. Although costing uncertainties remain, it is clear that development of easy and rapid replacement methods for reactor components is essential and that new staging concepts to reduce the implosion energy requirement must be pursued
Imploding to equilibrium of helically symmetric theta pinches
Sharky, N.N.
1978-01-01
The time-dependent, single-fluid, dissipative magnetohydrodynamic equations are solved in helical coordinates (r,phi), where phi = THETA-kz, k = 2π/L and L is the periodicity length in the z-direction. The two-dimensional numerical calculations simulate theta pinches which have an l = 1 helical field added to them. Given the applied magnetic fields and the initial state of the plasma, we study the time evolution of the system. The plasma is found to experience two kinds of oscillations, occurring on different time scales. These are the radial compression oscillations, and the slower helical oscillations of the plasma column. The plasma motion is followed until these oscillations disappear and an equilibrium is nearly reached. Hence given the amplitude and the rise time of the applied magnetic fields, the calculations allow one to relate the initial state of a cold, homogeneous plasma to its final equilibrium state where it is heated and compressed
Laser--plasma interaction in a theta-pinch geometry
Armstrong, W.T.
1978-06-01
Prompt stimulated Brillouin scatter (SBS) is studied in an experiment wherein a high power, pulsed CO 2 laser irradiates an independently produced, theta-pinch plasma. SBS does not significantly affect laser heating of the plasma. Measurements of density profiles and temperature histories permitted examination of laser refraction, local heating and net absorption. Refractive containment of the CO 2 laser beam by an on-axis density minimum was observed at early times during the laser pulse. However, refractive containment was lost at late times due to the diffusive loss of the density minimum. Classical modeling of the expected heating required ''bleached'' absorption to account for the observed heating. A plasma absorptivity of approximately 46% was inferred from calorimetry measurements at 250 mtorr fill pressure. These results confirm that classical heating and refraction dominated the laser-plasma interaction
Simulation of the implosion of a theta pinch
Busnardo Neto, J.; Leite Neto, J.P.; Jesus Paes, A.C. de
1982-01-01
A two-fluid model was used to simulate the implosion of a theta-pinch, with initial densities varying from 10 12 to 10 16 cm -3 . The gases used were hydrogen, helium, neon and argon; initial temperatures of 2 eV and total ionization were assumed. For hydrogen the anomalous resistivity is dominant everywhere when the density is low (ν sub(eff) - ω sub(pi)). For high densities both resistivities are not high enough to allow diffusion of the magnetic field during the time of the implosion (ν sub(eff) approximatelly 0.3 ω sub(pi)). For heavier gases a surprisingly high value of the anomalous resistivity was found, due to the greater mass, (ν sub(eff) approximatelly 10-12 ω sub(pi)). (Author) [pt
Experimental study of CF4 conical theta pinch plasma expanding into vacuum
Pedrow, P.D.; Nasiruddin, A.M.
1989-01-01
Langmuir probe, photodiode, and optical multichannel analyzer (OMA) measurements have been made on a pulsed CF 4 conical theta pinch plasma. A cloud of CF 4 gas was puffed into a conical theta pinch coil, converted to plasma, and propelled into the vacuum region ahead of the expanding gas cloud. At a position 67 cm away from the conical theta pinch coil, the plasma arrived in separate packets that were about 20 μs in duration. The average drift velocity of these packets corresponded to an energy of about 3 eV. The OMA measurements showed that the second packet contained neutral atomic fluorine as well as charged particles
Measurement of the ion temperature in a diffuse theta pinch
Kudo, Koichi; Watanabe, Yukio; Ogi, Sukeomi; Sumikawa, Toshio; Akazaki, Masanori
1979-01-01
The Doppler broadening of helium ion spectra was observed, and the ion temperature of theta pinch plasma was obtained. The apparatus for the measurement consists of a spectroscope, a photomultiplier and an oscilloscope. The time variation of initial plasma density was obtained. The doppler broadening of the spectra was observed in case of the plasma density of 2 x 10 13 /cm 3 and 3 x 10 12 /cm 3 . The analyses of the spectra gave the ion temperature. The double temperature distribution was seen. The temperature of the low temperature part was 5 to 9 electron-volt, and that of the high temperature part several hundred electron-volt. The high temperature is caused by the thermalization of particles accelerated by the magnetic piston. The decay of high temperature ions is due to the charge exchange with the neutral particles. The time of the highest temperature corresponds to the time at which the luminescent layer reaches to the central axis. (Kato, T.)
Liner of a thermonuclear pulse THETA-pinch reactor
Baranov, G.A.; Izotov, E.N.; Karasev, B.G.; Komin, A.V.; Krivosheev, M.V.; Levashov, A.D.
1975-01-01
Some possible constructive solutions to the problem of fabrication of the theta-pinch reactor liner by the method of centrifugal casting in a casting mould are considered. A scheme for liner manufacturing is presented, which includes the following elements: 1) a casting mould of dielectric material presenting a hollow cylinder of 4 m in diam., 3 m in length and 12 t in weight, which rotates at 8 rps in the reactor chamber; 2) a system for heat protection of the casting mould; the volume heat of the mould is suggested to remove by gaseous helium flowing under pressure along axial cooling channels of 5 mm in diam.; the channels are evenly distributed throughout the thickness of the mould shell; 3) a system for preparation and supply of a liquid metal to the casting mould, the metal is being supplied into the casting mould from its both ends at a rate of 1.7 t of the melt per second; 4) a system for rotation of the mould, which comprises two gas turbines mounted on both ends of the mould and two main stop-radial slip supports with gas lubrication
Results from TRX-2 slow field-reversed-theta-pinch
Slough, J.T.; Harding, D.; Hoffman, A.L.
1984-01-01
FRCs have been successfully generated in the TRX-2 slow risetime theta pinch. Initial studies indicate that the flux trapping through field reversal is about as good (''50%) as on TRX-1, although the quarter cycle time of the main coil was increased from 3 to 10 μsec. Formation studies have been started using the programmed formation techniques developed on TRX-1. The plasma dynamics are very similar to those exhibited in the faster rise TRX-1 experiments. The formation phase shows the same high degree of symmetry and reproducibility that was observed in TRX-1. Equilibrium behaviour of the FRCs formed is very similar to that observed on TRX-1, as long as impurity content is kept low. T/sub e/ + T/sub i/ temperatures of 400 to 500 eV are obtained and confirmed by impurity line broadening and decay rates. Flux and particle lifetimes ≅ 100 μsec have been observed and show the same strong scaling with x/sub s/ that was observed on TRX-1
Opacity test using a neon-seeded theta pinch
Thomson, D.B.
1980-02-01
Vacuum ultraviolet (VUV) emission from a neon-seeded high-density theta-pinch has been observed for comparison with theoretical radiation emission calculations. The plasma was created in a 25-cm-long theta-coil with 90-kG field having a 3.0-μs quarter period. A gas fill of 1 torr of helium + 2% neon was used. Observation of the HeII 4686 line/continuum ratio gave an electron temperature of 25 +- 4 eV. Shadowgraphs of the plasma radius, taken with a ruby laser, gave an electron density of 0.9 +- 0.09 x 10 18 cm -3 . The VUV emission was observed in radial view and with time resolution with a 2.2-m grazing-incidence monochromator equipped with a photomultiplier and p-terphenyl scintillator. Thin foils of carbon and aluminum were used as filters to absorb stray light and pass emission in the 44- to 100-A region
Plasma behaviors in the open field region of reversed-field theta-pinch
Aso, Yoshiyuki; Hirano, Keiichi.
1983-03-01
A characteristic behavior of the plasma in an open field region of reversed field theta pinch has been studied with the guide field (GF) which extends the field line along the axial direction. The experimental result suggests that the rotaional instability may be induced in FRC after the plasma touches the wall at the ends of the open field. (author)
Operating point considerations for the Reference Theta-Pinch Reactor (RTPR)
Krakowski, R.A.; Miller, R.L.; Hagenson, R.L.
1976-01-01
Aspects of the continuing engineering design-point reassessment and optimization of the Reference Theta-Pinch Reactor (RTPR) are discussed. An updated interim design point which achieves a favorable energy balance and involves relaxed technological requirements, which nonetheless satisfy more rigorous physics and engineering constraints, is presented
Hagenson, R.L.; Krakowski, R.A.
1980-01-01
Early scoping studies based on approximate, analytic models have been extended on the basis of a dynamic plasma model and an overall systems approach to examine a Compact Toroid (CT) reactor embodiment that uses a Field-Reversed Theta Pinch as a plasma source. The field-reversed plasmoid would be formed and compressionally heated to ignition prior to injection into and translation through a linear burn chamber, thereby removing the high-technology plasmoid source from the hostile reactor environment. Stabilization of the field-reversed plasmoid would be provided by a passive conduction shell located outside the high-temperature blanket but within the low-field superconducting magnets and associated radiation shielding. On the basis of this batch-burn but thermally steady-state approach a reactor concept emerges with a length below approx. 40 m that generates 300 to 400 MWe of net electrical power with a recirculating power fraction less than 0.15
Abdou, M.; Burke, R.J.; Dauzvardis, P.V.; Foss, M.; Gerstl, S.A.W.; Maroni, V.A.; Pierce, A.W.; Turner, A.F.; Krakowski, R.A.; Linford, R.K.; Oliphant, T.A.; Ribe, F.L.; Thomassen, K.I.
1975-01-01
This paper describes two advanced toroidal theta-pinch devices which are being proposed for future construction. The Fusion Test Reactor (FTR) is being designed to produce thermonuclear energy (at 20 MeV/neutron) equal to the maximum plasma energy (Q=1) and to demonstrate α-particle heating. The Fusion Engineering and Research Facility (FERF) is being designed to test materials in a fusion environment where the average 14-MeV neutron flux from the plasma is greater than or of the order of 5.10 13 n/cm 2 .s over large surface areas. These devices employ the staged theta-pinch principle where the heating is accomplished by rapid (about 0.1 μs) implosion and expansion followed by a slow compression of the plasma. The rapid implosion injects as much heat as possible at as large a plasma radious as possible so that the plasma remains stable even after further compression. The final compression to ignition requires the transfer of a large amount of magnetic energy which implies a long transfer time (about 1 ms) for realistic voltages in the driving circuit. Throughout the heating and burn cycle the plasma must remain in equilibrium and stable to the dominant MHD-modes. A sufficiently large plasma radius guarantees stability against the m = 1 modes. These equilibrium and stability conditions and the requirements on thermonuclear burn determine the design parameters for either machine. The design parameters must also be consistent with economic limitations and technological feasibility of components. In addition to these requirements, the FERF must provide a steady and reliable source of fusion neutrons. (author)
Bartsch, R.R.; Buchenauer, C.J.; Cantrell, E.L.
1977-01-01
Results of the Los Alamos theta-pinch program in three areas of investigation are summarized: 1) In the Staged Theta Pinch, results are reported on the effects of magnetic field amplitude and time history of plasma formation. 2) In the Implosion Heating Experiment, density, internal-magnetic field and neutron measurements yield a consistent picture of the implosion which agrees with kinetic computations and with a simple dynamic model of the ions and magnetic piston. 3) In the Scyllac Feedback-Sector Experiment, the l=1, 0 equilibrium plasma parameters have been adjusted to accommodate the feedback stabilization system. With a uniform toroidal discharge tube the m=1 instability is feedback-stabilized in the vertical direction, and confinement in the toroidal direction is extended by feedback control. Results with a helical discharge tube are also reported. (author)
The theta-pinch - a versatile tool for the generation and study of high temperature plasmas
Hintz, E. [Inst. fuer Plasmaphysik, Forschungszentrum-Juelich GmbH (Germany)
2004-07-01
The more general technical and physical features of theta-pinches are described. Special field of their application are high-ss plasmas. Two examples are analysed and studied in more detail: a high density plasma near thermal equilibrium and a low density plasma far from equilibrium. The latter is of special interest for future investigations. Possibilities of field-reversed configurations are pointed out. (orig.)
The theta-pinch - a versatile tool for the generation and study of high temperature plasmas
Hintz, E.
2004-01-01
The more general technical and physical features of theta-pinches are described. Special field of their application are high-ss plasmas. Two examples are analysed and studied in more detail: a high density plasma near thermal equilibrium and a low density plasma far from equilibrium. The latter is of special interest for future investigations. Possibilities of field-reversed configurations are pointed out. (orig.)
Computer simulation of a staging system for a theta-pinch reactor (RTPR)
Crnkovich, P.G.
1976-02-01
To reduce excessive energy requirements for the implosion heating system of a theta-pinch reactor, two staging methods, the brute force and bucking field options, were proposed. A Marshall coil and a segmented coil were also considered. Calculations involved in coding these coil designs and staging options into a PL/I subprogram are described. A marked savings in the energy required for the IH system is realized with the bucking option and others
The UNICAMP theta-pinch for spectroscopic study of plasma radiations
Trigueiros, A.G.; Luna, F.R.T.; Holanda Cavalcanti, G. de; Mania, A.J.
1993-01-01
The emission spectrum of six times ionized xenon (Xe VII), has been observed in the vacuum ultraviolet (VUV) using a theta-pinch discharge. The spectrum was recorded with a 2-meter normal incidence spectrograph in the 300-2000 A region. Preliminary results allow the identification of transitions in the n=5 complex. Ten of these transitions were identified. The identifications are supported by relativistic Hartree-Fock calculations. (author)
Necessary stability condition for field-reversed theta pinches
Cary, J.R.
1981-03-01
Toroidal systems of arbitrary cross section without toroidal magnetic field are analyzed via the double adiabatic fluid equations. Such systems are shown to be unstable if there exists one closed field line on which the average of kapparB 2 is positive, where kappa is the curvature. A similar criterion is derived for linear systems and is applied to a noncircular z-pinch
END effects on the n = 2 rotational instability in the reversed field theta-pinch
Aso, Y.; Wu, Ch.; Himeno, S.; Hirano, K.
1981-07-01
It is observed that n = 2 rotational mode which appears in the field reversed configuration created by a theta-pinch can be stabilized if the ejected plasmas from the ends are guided out to the far ends of the apparatus by long axial solenoidal fields. This is understood from the fact that endshorting becomes no longer possible before the ejecting plasma tips reach to the ends. Measurement of plasma rotations just outside the separatrix suggests that both preferential diffusion loss and endshorting play a very important role for the n = 2 mode. (author)
A new formulation of theta pinch implosions - a collisionless wave model
Tsui, K.H.
Previous work in theta pinch implosions is characterized by anomalous resistivity owing its origin to plasma instabilities. A diametrically opposite collisionless model is proposed here that consists of an inhomogeneous wave equation. The electron velocities are solved by guiding center approximation. This model offers qualitative explanations to various effects like experimental Alfven scaling law, Alfven penetration time, sheath thickness, shock formation, shock width, piston thickness, Alfven Mach number. Although collision is not essential, the plasma has an apparent resistivity with an effective collision frequency of roughly the same as those anomalous ones used in turbulent model. (Author) [pt
Refrigeration requirements for fusion reactors based upon the theta-pinch concept
Williamson, K.D. Jr.; King, C.R.
1976-01-01
Two refrigeration systems applicable to the theta-pinch fusion concept are described. The first is a 1100 W, 4.5 K refrigerator which will be used for testing superconducting NbTi Magnetic Energy Transfer and Storage (METS) coil systems. This unit is currently being installed and is to be operational by April 1977. The second unit is applicable to the Syllac Fusion Test Reactor (SFTR) and has been conceptually designed. This liquefier-refrigerator is about 22 times larger than those in existence at present and will require 12-MW input electrical power. It will provide 3045 kg/h of liquid helium at 4.5 K
Transient loss of plasma from a theta pinch having an initially reversed magnetic field
Heidrich, J.E.
1981-01-01
The results of an experimental study of the transient loss of plasma from a 25-cm-long theta pinch initially containing a reversed trapped magnetic field are presented. The plasma, amenable to MHD analyses, was a doubly ionized helium plasma characterized by an ion density N/sub i/ = 2 x 10 16 cm -3 and an ion temperature T/sub i/ = 15 eV at midcoil and by N/sub i/ = 0.5 x 10 16 cm -3 and T/sub i/ = 6 eV at a position 2.5 cm beyond the end of the theta coil
Newton, A.A.
1986-01-01
Field-reversed configurations (FRC) and theta pinches with trapped reversed bias field are essentially the same magnetic confinement systems using closed magnetic field lines inside an open-ended magnetic flux tube. A simple model of joule heating and parallel electron thermal conduction along the open flux lines to an external heat sink gives the electron temperature as Tsub(e)(eV) approx.= 0.05 Bsup(2/3)(G)Lsup(1/3)(cm), where B is the magnetic field and L is the coil length. This model appears to agree with measurements from present FRC experiments and past theta-pinch experiments which cover a range of 40-900 eV. The energy balance in the model is dominated by (a) parallel electron thermal conduction along the open field lines which has a steep temperature dependence, Q is proportional to Tsub(e)sup(7/2), and (b) the assumed rapid perpendicular transport in the plasma bulk which, in experiments to date, may be due to the small number of ion gyroradii across the plasma. (author)
FRC formation studies in a field reversed theta pinch with a variable length coil
Maqueda, R.; Sobehart, J.; Rodrigo, A.B.
1987-01-01
The formation phase of field reversed configurations (FRC) produced using a theta pinch has received considerable attention lately in connection with the possibility of developing formation methods in time scales longer than the Alven radial time, which would permit the use of low-voltage technology and represent an important engineering simplification in the trend towards larger scale machines sup (1)). The mechanisms leading to the loss of trapped reversed flux during the preheating 2 ) and formation sup (3,4)) stages, looking for maximization of this quantity in order to improve on the stability and transport properties of the configuration in its final equilibrium state are investigated. As a result, semi-emperical scaling laws have been obtained relating the reversed flux loss with experimental operating parameters during the early stages of the formation process 1 ). (author) [pt
Hoffman, A.L.; Armstrong, W.T.
1982-01-01
TRX-1 is a new 20 cm diameter, 1-m long field reversed theta pinch with a magnetic field swing of 10 kG in 3 μsec. It employs z discharge preionization and octopole barrier fields to maximize flux trapping on first half cycle operation. Cusp coils are used at the theta pinch ends to delay reconnection and fast mirror coils are used to trigger reconnection at a time designed to maximize axial heating efficiency and toroid lifetime. These controls are designed to study toroid formation methods which are claimed to be especially efficient by Russian experimenters. Studies have been conducted on flux trapping efficiency, triggered reconnection, and equilibrium and lifetime
Fabrication of a segmented composite stainless steel-alumina discharge tube for a theta-pinch coil
Dickinson, J.M.; Stoddard, S.D.; Muller, J.F.
1975-11-01
An 80-mm-diam segmented discharge tube that simulated in a simplified way the blanket and first wall of the Reference Theta-Pinch Reactor (RTPR) has been constructed. The segments were fabricated by plasma-arc spraying an alumina coating on tubular stainless steel trapezoids. These were laid up to form a cylinder that was contained in a fully dense alumina vacuum tube. The fabrication processes are discussed in detail
First wall thermal--mechanical analyses of the reference theta-pinch reactor
Krakowski, R.A.; Hagenson, R.L.; Cort, G.E.
1977-01-01
The thermal-mechanical response of the Reference Theta-Pinch Reactor (RTPR) first wall was analyzed. The first wall problems anticipated for a pulsed, high-β fusion power plant can be ameliorated by either alterations in the physics operating point, materials reengineering, or blanket/first wall reconfiguration. Within the latter ''configuration'' scenario, a two-fold approach has been adopted for the thermal-mechanical portion of the RTPR first wall technology assessment. First, a number of new first wall configurations (bonded or unbonded laminated composites, all-ceramic structures, protective and/or sacrificial ''bumpers'') were considered. Second, a more quantitative failure criterion, based on the developing theories of fracture mechanics, was identified. For each first wall configuration, transient heat transfer and thermoelastic stress calculations have been made. Two-dimensional finite element structural analyses have been made for a variety of mechanical boundary conditions. Only the Al 2 O 3 /Nb - 1 Zr system has been considered. The results of this study indicated a wide range of design solutions to the pulsed thermal stress problem anticipated for the RTPR
Implosion heating studies in the Scylla 1B, implosion heating, and staged theta-pinch experiments
Gribble, R.F.; Hammel, J.E.; Henins, I.; Jahoda, F.C.; Kristal, R.; Linford, R.K.; Marshall, J.; McKenna, K.F.; Sherwood, A.R.; Thomas, K.S.
1975-01-01
Three experiments designed to study various aspects of implosion heating in the plasma density range (10 14 -10 16 cm -3 ) used in present theta pinches are described. Initial plasma studies show that, provided a sufficiently high pre-ionization level (>10 14 cm -3 ) is achieved, plasma behaviour is qualitatively the same over a range of two in initial magnetic field rise and a range of four in initial gas fill. The implosion phase is characterized by rapid changes in magnetic-field diffusion rates, the plasma resistivity decreasing rapidly with time. During the implosion some of the plasma density observed is moving ahead of the magnetic piston. Magnetic-field gradients occur in the region outside the area of measurable plasma density implying the presence of hot, low-density plasma in this region. In experiments where the external magnetic field decreases before the maximum compression of the plasma column, secondary breakdown occurs at the discharge tube wall which slows the rate at which magnetic flux diffuses out of the discharge tube. (author)
Engineering design study of a reference theta-pinch reactor (RTPR): environmental impact study
Draley, J.E.; Krakowski, R.A.; Coultas, T.A.; Maroni, V.A.
1975-03-01
The recently completed engineering design study for the Reference Theta-Pinch Reactor (RTPR) has allowed an assessment of the potential environmental impact of an RTPR power plant to be made. During normal operation of the plant, tritium is expected to be released at a rate of 6 Ci/day, an amount that would lead to low maximum doses (0.06 to 0.8 mrem/yr, depending on site and cooling options). These doses, and the anticipated integrated population doses, are considerably less than doses now considered acceptable. Problems related to (i) the required commitment of some natural resources (e.g., beryllium and niobium), (ii) the disposition of activated structural materials and other radioactive waste (76,700 kg/yr or 12 GCi/yr at shutdown) for a five-year niobium component lifetime, and (iii) land despoilment are substantial but do not appear to compromise the viability of RTPR's as a useful power source. Consideration of the occurrence of severe accidents (e.g., liquid-metal fires) and other unusual incidents indicate that their effects will be contained within the plant, but that they may be costly. Radiation doses resulting from accidental release of the operating tritium inventory during a liquid-metal fire would probably be below the level now permitted for fission plants. (U.S.)
Numerical simulation of a theta-pinch: two-dimensional hybrid model
Zenum, C.S.S.
1987-01-01
A numerical code based on a 2D-hybrid model, were the electrons are considered as a fluid of zero mass and the ions as discrete particles, was elaborated. The magnetic field responsable by ion acceleration was obtained from equation of motion of the electrons and Maxwell equations. The ions are randomly distributed in a space phase of five dimensions (Vr, Vo, Vz, r, z), according to the Maxwellian. The equation of motion is solved for each ion, and the distribution functions of ion is obtained by the technique of particle into the box. The resistivity was classically and phenomenologically treated. The model was applied to theta-pinch to study: the plasma physical behaviour during the phase of implosion; the effect of reflected ions by magnetic piston; and the effect of magnetic field line reconnection 3D graphics of magnetic field, electric field current density, particle, and pressure densities, electron temperature, ion temperature is presented space phase of ion velocity in function of the position is also shown. The obtained results allow to characterized the obtained phenomena which occur during the phase of implosion. (M.C.K.) [pt
Coaxial plasma guns as injectors of high beta linear theta pinches
Marshall, J.
1975-01-01
A brief review of research on coaxial plasma guns and their use is given. Some problems and possibilities of using this gun for beam injection experiments are pointed out. Some scaling laws for gun energy are described
Equilibrium and stability of theta-pinch plasma in modified toroidal multiple mirror field
Shiina, S.; Saito, K.; Osanai, Y.; Itagaki, T.; Karakizawa, T.; Gesso, H.; Todoroki, J.; Kawakami, I.; Yoshimura, H.
1976-01-01
To confine a high-beta plasma a new toroidal magnetic configuration with closed lines of force has been proposed [1]. The configuration is an appropriate superposition of l = 0, l = +- 1, l = +- 2,sup(...), helical fields. In this experiment, it is generated by modifying the multiple mirror field by enclosing the discharge tube in a copper shell which has longitudinal gap. This configuration is preferred for the wall stabilizing effect to that with the separated helical windings. The characteristics of the equilibrium conditions are examined based on the near-axis approximation theory and compared with the experimental results. The stability of plasma in the configurations with l = 0 field and with superposition of l = 0, l = +- 2 fields is investigated in linear geometry. (author)
High density linear systems for fusion power
Ellis, W.R.; Krakowski, R.A.
1975-01-01
The physics and technological limitations and uncertainties associated with the linear theta pinch are discussed in terms of a generalized energy balance, which has as its basis the ratio (Q/sub E/) of total electrical energy generated to net electrical energy consumed. Included in this total is the virtual energy of bred fissile fuel, if a hybrid blanket is used, as well as the actual of real energy deposited in the blanket by the fusion neutron. The advantages and disadvantages of the pulsed operation demanded by the linear theta pinch are also discussed
Electromagnetic device of linear displacement
Savary, F.; Le Saulnier, G.
1986-01-01
The device moves a rod integral with a nuclear reactor control element. It has a grab for the rod operated by a mobil pole drive by a coil carried by a surrounding sealed casing, a second grab with fixed and mobile poles with facing surfaces shaped to limit the variation of magnetic force with distance between them, and a plunger driven by a coil to bear against another mobile pole moved by a coil. The invention proposes a device ensuring a displacement while the impact forces at the different level of the mechanism are reduced [fr
Armstrong, P.E.; Krakowski, R.A.
1977-06-01
The results of a ''proof-of-principle'' Thermal Shock Experiment (TSEX), designed to simulate the thermal mechanical response of insulator-metal composite first walls anticipated for pulsed high-density fusion reactors, are given. A programmable 10-kV, 1.0-A electron beam was used to pulse repeatedly (0.30-mm)Al 2 O 3 /(1.0-mm) Nb-1Zr composite samples 200 to 300 K, relative to a base-line temperature of 1000 K. The experimental goals of TSEX were established relative to the first-wall environment anticipated for the Reference Theta-Pinch Reactor (RTPR). A detailed description of the TSEX ''proof-of-principle'' apparatus, experimental procedure, and diagnostics is given. The results of extensive thermal analyses are given, which are used to estimate the thermal stresses generated. Although little or no control was exercised over the sample fabrication and thermal history, one sample experienced in excess of 800 thermal cycles of approximately 250 K at approximately 1000 K, and the results of optical and SEM examination of this specimen are presented. The resistance of this sample to macroscopic failure was truly impressive. Recommendations for the construction of an apparatus dedicated to extensive testing of first-wall composites are given on the basis of these ''proof-of-principle'' TSEX results
Computer simulation of plasma behavior in open-ended linear theta machines. Scientific report 81-5
Stover, E. K.
1981-04-01
Zero-dimensional and one-dimensional fluid plasma computer models have been developed to study the behavior of linear theta pinch plasmas. Computer simulation results generated from these codes are compared with data obtained from two theta pinch experiments so that significant machine plasma behavior can be identified. The experiments examined are a collisional experiment, T/sub i/ approx. 50 eV, n/sub e/ approx. 10/sup 17/ cm/sup -3/, where the plasma mean-free-path was significantly less than the plasma column length, and a hot ion species experiment, T/sub i/ approx. 3 keV, n/sub e/ approx. 10/sup 16/ cm/sup -3/, where the ion mean-free-path was on the order of the plasma column length.
Computer simulation of plasma behavior in open-ended linear theta machines. Scientific report 81-5
Stover, E.K.
1981-04-01
Zero-dimensional and one-dimensional fluid plasma computer models have been developed to study the behavior of linear theta pinch plasmas. Computer simulation results generated from these codes are compared with data obtained from two theta pinch experiments so that significant machine plasma behavior can be identified. The experiments examined are a collisional experiment, T/sub i/ approx. 50 eV, n/sub e/ approx. 10 17 cm -3 , where the plasma mean-free-path was significantly less than the plasma column length, and a hot ion species experiment, T/sub i/ approx. 3 keV, n/sub e/ approx. 10 16 cm -3 , where the ion mean-free-path was on the order of the plasma column length
Linearity correction device for a scintillation camera
Lange, Kai
1978-06-16
This invention concerns the scintillation cameras still called gamma ray camera. The invention particularly covers the improvement in the resolution and the uniformity of these cameras. Briefly, in the linearity correction device of the invention, the sum is made of the voltage signals of different amplitudes produced by the preamplifiers of all the photomultiplier tubes and the signal obtained is employed to generate bias voltages which represent predetermined percentages of the sum signal. In one design mode, pairs of transistors are blocked when the output signal of the corresponding preamplifier is under a certain point on its gain curve. When the summation of the energies of a given scintillation exceeds this level which corresponds to a first percentage of the total signal, the first transistor of each pair of each line is unblocked, thereby modifying the gain and curve slop. When the total energy of an event exceeds the next preset level, the second transistor is unblocked to alter the shape again, so much so that the curve shows two break points. If needs be, the device can be designed so as to obtain more break points for the increasingly higher levels of energy. Once the signals have been processed as described above, they may be used for calculating the co-ordinates of the scintillation by one of the conventional methods.
Global numerical modeling of magnetized plasma in a linear device
Magnussen, Michael Løiten
Understanding the turbulent transport in the plasma-edge in fusion devices is of utmost importance in order to make precise predictions for future fusion devices. The plasma turbulence observed in linear devices shares many important features with the turbulence observed in the edge of fusion dev...... with simulations performed at different ionization levels, using a simple model for plasma interaction with neutrals. It is found that the steady state and the saturated state of the system bifurcates when the neutral interaction dominates the electron-ion collisions.......Understanding the turbulent transport in the plasma-edge in fusion devices is of utmost importance in order to make precise predictions for future fusion devices. The plasma turbulence observed in linear devices shares many important features with the turbulence observed in the edge of fusion...... devices, and are easier to diagnose due to lower temperatures and a better access to the plasma. In order to gain greater insight into this complex turbulent behavior, numerical simulations of plasma in a linear device are performed in this thesis. Here, a three-dimensional drift-fluid model is derived...
Intrinsic suppression of turbulence in linear plasma devices
Leddy, J.; Dudson, B.
2017-12-01
Plasma turbulence is the dominant transport mechanism for heat and particles in magnetised plasmas in linear devices and tokamaks, so the study of turbulence is important in limiting and controlling this transport. Linear devices provide an axial magnetic field that serves to confine a plasma in cylindrical geometry as it travels along the magnetic field from the source to the strike point. Due to perpendicular transport, the plasma density and temperature have a roughly Gaussian radial profile with gradients that drive instabilities, such as resistive drift-waves and Kelvin-Helmholtz. If unstable, these instabilities cause perturbations to grow resulting in saturated turbulence, increasing the cross-field transport of heat and particles. When the plasma emerges from the source, there is a time, {τ }\\parallel , that describes the lifetime of the plasma based on parallel velocity and length of the device. As the plasma moves down the device, it also moves azimuthally according to E × B and diamagnetic velocities. There is a balance point in these parallel and perpendicular times that sets the stabilisation threshold. We simulate plasmas with a variety of parallel lengths and magnetic fields to vary the parallel and perpendicular lifetimes, respectively, and find that there is a clear correlation between the saturated RMS density perturbation level and the balance between these lifetimes. The threshold of marginal stability is seen to exist where {τ }\\parallel ≈ 11{τ }\\perp . This is also associated with the product {τ }\\parallel {γ }* , where {γ }* is the drift-wave linear growth rate, indicating that the instability must exist for roughly 100 times the growth time for the instability to enter the nonlinear growth phase. We explore the root of this correlation and the implications for linear device design.
Ionization effects and linear stability in a coaxial plasma device
Kurt, Erol; Kurt, Hilal; Bayhan, Ulku
2009-03-01
A 2-D computer simulation of a coaxial plasma device depending on the conservation equations of electrons, ions and excited atoms together with the Poisson equation for a plasma gun is carried out. Some characteristics of the plasma focus device (PF) such as critical wave numbers a c and voltages U c in the cases of various pressures Pare estimated in order to satisfy the necessary conditions of traveling particle densities ( i.e. plasma patterns) via a linear analysis. Oscillatory solutions are characterized by a nonzero imaginary part of the growth rate Im ( σ) for all cases. The model also predicts the minimal voltage ranges of the system for certain pressure intervals.
Thermoelectric efficiency of nanoscale devices in the linear regime
Bevilacqua, G.; Grosso, G.; Menichetti, G.; Pastori Parravicini, G.
2016-12-01
We study quantum transport through two-terminal nanoscale devices in contact with two particle reservoirs at different temperatures and chemical potentials. We discuss the general expressions controlling the electric charge current, heat currents, and the efficiency of energy transmutation in steady conditions in the linear regime. With focus in the parameter domain where the electron system acts as a power generator, we elaborate workable expressions for optimal efficiency and thermoelectric parameters of nanoscale devices. The general concepts are set at work in the paradigmatic cases of Lorentzian resonances and antiresonances, and the encompassing Fano transmission function: the treatments are fully analytic, in terms of the trigamma functions and Bernoulli numbers. From the general curves here reported describing transport through the above model transmission functions, useful guidelines for optimal efficiency and thermopower can be inferred for engineering nanoscale devices in energy regions where they show similar transmission functions.
Review of the current status of linear hybrid reactor concepts
Schultz, K.R.
1977-07-01
A review was made of the current status of linear fusion-fission hybrid reactor design studies in the USA. The linear hybrid reactor concepts reviewed include the linear theta-pinch hybrid reactor being studied at Los Alamos Scientific Laboratory, the electron beam-heated solenoid hybrid reactor under development at Physics International Co., the laser-heated solenoid hybrid reactor being investigated at Mathematical Sciences Northwest, Inc., and the linear fusion waste burning reactor being studied at General Atomic Company. The discussion addresses confinement and heating mechanisms for each concept, as well as the hybrid blanket designs. The current state of the four reactor designs is summarized and the performance of the various concepts compared
EBW and Whistler propagation and damping in a linear device
Diem, S. J.; Caughman, J. B. O.; Harvey, R. W.; Petrov, Yu.
2011-10-01
Linear plasma devices are an economic method to study plasma-material interactions under high heat and particle fluxes. ORNL is developing a large cross section, high-density helicon plasma generator with additional resonant electron heating to study plasma-material interactions in ITER like conditions. The device will produce a heat flux of 10-20 MW/m2 and particle flux of 1024 /m2/s in a high recycling plasma near a target plate with a magnetic field of ~1 T. As part of this effort, heating of overdense plasma is being studied using a microwave-based plasma experiment. The plasma is initiated with a high-field launch of 18 GHz whistler waves producing a moderate-density plasma of ne ~1018 m-3. Electron heating of the overdense plasma can be provided by either whistler waves or EBW at 6 and 18 GHz. A modified GENRAY (GENRAY-C) ray-tracing code has been used to determine EBW and ECH whistler wave accessibility for these overdense plasmas. These results combined with emission measurements will be used to determine launcher designs and their placement. ORNL is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC-05-00OR22725.
Thermal and radiation losses in a linear device
Rosenau, P.; Degani, D.
1980-01-01
An analysis is presented of the electron temperature in a linear device which includes the effect of thermal conduction, heat flux limit, radiation, and end plugs. It is found that the thermal conduction and the heat flux limit are dominant in the initial phase of cooling, while the later phase is almost completely controlled by radiation that spatially homogenizes the temperature distribution. In the case of bremsstrahlung, within the frame of the present model, the temperature decays to zero in a finite time. This process takes the form of a cooling wave that moves from the ends of the column to the center. Impurities cause a milder, exponential decay, which is still much faster than the algebraic conduction decay. The thermal effectiveness of the end plugs is described by a convective transfer coefficient h/sub p/. Its scaling law (in terms of the coupled plamsa-plug system) reveals that a very high plug-plasma density ratio provides a simple way to significantly retard the cooling
Lithographic linear motor, lithographic apparatus, and device manufacturing method
2006-01-01
A linear motor having a high driving force, high efficiency and low normal force comprises two opposed magnet tracks and an armature comprising three open coil sets. The linear motor may be used to drive a stage, such as, for example, a mask or wafer stage, in a lithographic apparatus.
Poloidal flux loss in a field-reversed theta pinch
Hoffman, A.L.; Milroy, R.D.; Steinhauer, L.C.
1981-01-01
Poloidal flux loss has been measured in field-reversed configurations and related to anomalous resistivity near the magnetic field null. The results indicate that mechanisms in addition to the lower-hybrid drift instability are affecting transport
Efficient Implementation of Solvers for Linear Model Predictive Control on Embedded Devices
Frison, Gianluca; Kwame Minde Kufoalor, D.; Imsland, Lars
2014-01-01
This paper proposes a novel approach for the efficient implementation of solvers for linear MPC on embedded devices. The main focus is to explain in detail the approach used to optimize the linear algebra for selected low-power embedded devices, and to show how the high-performance implementation...
Instrumentation for Linear and Nonlinear Optical Device Characterization
2018-01-31
distribution is Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The Pl has acquired six pieces of equipment to extend capabilities for linear and nonlinear...optical spectral analysis • Frequency comb generation in mid-infrared Accomplishments Six major pieces of equipment have been ordered and received
Wideband energy harvesting for piezoelectric devices with linear resonant behavior.
Luo, Cheng; Hofmann, Heath F
2011-07-01
In this paper, an active energy harvesting technique for a spring-mass-damper mechanical resonator with piezoelectric electromechanical coupling is investigated. This technique applies a square-wave voltage to the terminals of the device at the same frequency as the mechanical excitation. By controlling the magnitude and phase angle of this voltage, an effective impedance matching can be achieved which maximizes the amount of power extracted from the device. Theoretically, the harvested power can be the maximum possible value, even at off-resonance frequencies. However, in actual implementation, the efficiency of the power electronic circuit limits the amount of power harvested. A power electronic full-bridge converter is built to implement the technique. Experimental results show that the active technique can increase the effective bandwidth by a factor of more than 2, and harvests significantly higher power than rectifier-based circuits at off-resonance frequencies.
Barnes, D.C.; Cayton, T.E.
1980-01-01
The ideal magnetohydrodynamic stability of the diffuse linear pinch is studied in the special case when the poloidal magnetic field component is small compared with the axial field component. A two-term approximation for growth rates is derived by straightforward asymptotic expansion in terms of a small parameter that is proportional to (B/sub theta//rB/sub z/). Evaluation of the second term in the expansion requires only a trivial amount of additional computation after the leading-order eigenvalue and eigenfunction are determined. For small, but finite, values of the expansion parameter the second term is found to be non-negligible compared with the leading term. The approximate solution is compared with exact solutions and the range of validity of the approximation is investigated. Implications of these results to a wide class of problems involving weakly unstable near theta-pinch configurations are discussed
Kinetic approach to plasma end loss from linear devices
Dreicer, H.
1976-01-01
A first step in the direction of a kinetic approach to end loss has been presented. This approach brings to light some fundamental processes not uncovered by the magnetohydrodynamic or guiding center approach. Attention was focused on the basically transient phenomenon in a way that describes the quite different behavior of collision dominated and collisionless ions, but ignores the magnetic nozzle effects near the ends of the system. The treatment illuminates some of the roles played by the parameter l/sub ii//L, and suggests the direction for more detailed investigations. End loss from linear systems is a very many faceted problem. Kinetic effects, magnetic effects, heat flow, etc. are all intermixed, and it will require a strong long term experimental and theoretical program to unravel all of its mysteries
Linear devices in combined high-level radiation environments
van Vonno, N.W.
1987-01-01
The design of precision analog integrated circuits for use in combined high-level radiation environments has traditionally been on a full-custom basis. The use of semicustom design methods has become prevalent in digital devices, with standard cell libraries and gate arrays readily available from multiple vendors. This paper addresses the application of semicustom design techniques to analog parts. In all cases the emphasis is on bipolar technology, since this provides an optimal combination of precision and radiation hardness. A mixed mode analog/digital (A/D) cell family for implementing semicustom designs is described, together with the fabrication process used. Specific processing and design methods are used to provide circuit hardness against neutron, total gamma dose, and transient gamma environments. Semicustom mixed analog/digital design is seen as an appropriate methodology for implementation of medium-performance mixed mode functions for radiation-hardened applications. This leads to trade-offs in process complexity and performance. Full custom design remains necessary for demanding applications such as high-speed A/D conversion and associated sample/hold functions. An A/D cell family optimized for hardness is described, together with the bipolar process used to implement it
Linear theory of the tearing instability in axisymmetric toroidal devices
Rogister, A.; Singh, R.
1988-08-01
We derive a very general kinetic equation describing the linear evolution of low m/l modes in axisymmetric toroidal plasmas with arbitrary cross sections. Included are: Ion sound, inertia, diamagnetic drifts, finite poloidal beta, and finite ion Larmor radius effects. Assuming the magnetic surfaces to form a set of nested tori with circular cross sections of shifted centers, and introducing adequate simplifications justified by our knowledge of experimental tokamak plasmas, we then obtain explicitely the sets of equations describing the coupling of the quasimodes 0/1, 1/1, 2/1, and, for m≥2, m/1, (m+1)/1. By keeping finite aspect ratio effects into account when calculating the jump of the derivative of the eigenfunction, it is shown that the theory can explain the rapid evolution, within one sawtooth period, of the growth rate of the sawteeth precursors from resistive values to magnetohydrodynamic ones. The characteristics thus theoretically required from current profiles in sawtoothing discharges have clearly been observed. Other aspects of the full theory could be relevant to the phenomenon of major disruptions. (orig.)
Novel AC Servo Rotating and Linear Composite Driving Device for Plastic Forming Equipment
Liang, Jin-Tao; Zhao, Sheng-Dun; Li, Yong-Yi; Zhu, Mu-Zhi
2017-07-01
The existing plastic forming equipment are mostly driven by traditional AC motors with long transmission chains, low efficiency, large size, low precision and poor dynamic response are the common disadvantages. In order to realize high performance forming processes, the driving device should be improved, especially for complicated processing motions. Based on electric servo direct drive technology, a novel AC servo rotating and linear composite driving device is proposed, which features implementing both spindle rotation and feed motion without transmission, so that compact structure and precise control can be achieved. Flux switching topology is employed in the rotating drive component for strong robustness, and fractional slot is employed in the linear direct drive component for large force capability. Then the mechanical structure for compositing rotation and linear motion is designed. A device prototype is manufactured, machining of each component and the whole assembly are presented respectively. Commercial servo amplifiers are utilized to construct the control system of the proposed device. To validate the effectiveness of the proposed composite driving device, experimental study on the dynamic test benches are conducted. The results indicate that the output torque can attain to 420 N·m and the dynamic tracking errors are less than about 0.3 rad in the rotating drive. the dynamic tracking errors are less than about 1.6 mm in the linear feed. The proposed research provides a method to construct high efficiency and accuracy direct driving device in plastic forming equipment.
Otsuka, J; Tanaka, T; Masuda, I
2010-01-01
A new type of linear motor described in this note has some advantages compared with conventional motors. The attractive magnetic force between the stator (permanent magnets) and mover (armature) is diminished almost to zero. The efficiency is better because the magnetic flux leakage is very small, the size of motor is smaller and detent (force ripple) is smaller than for conventional motors. Therefore, we think that this motor is greatly suitable for ultra-precision positioning as an actuator. An ultra-precision positioning device using this motor and linear motion ball guide ways is newly developed by making the device very rigid and using a suitable control method. Moreover, the positioning performance is evaluated by a positioning resolution, and deviation and dispersion errors. As a result of repeated step response tests, the positioning resolution is 0.3 nm, with the deviation error and dispersion error (3σ) being sub-nanometer. Consequently, the positioning device achieves sub-nanometer positioning. (technical design note)
On the problem of linear calibration for a reading system of measuring devices
Shigaev, V.N.
1978-01-01
The problem of gauging the frame of reference of a measuring device has been giVen a general approach which consists in finding an approximated inverse transformation on the basis of a partial diagram of a direct transformation which is defined on a given set, D, within the limits of the device measuring range. The following linear models of frame of reference are discussed: a general oblique system; a rectangular system with axes having different scales; a rectangular system with similar scale axes. Linear distortion for two rectangular models has been assessed. It is pointed out that the best approximation to the reduction operation should be found over the D set
Linear motion device and method for inserting and withdrawing control rods
Smith, J. E.
1984-01-01
A linear motion device, more specifically a control rod drive mechanism (CRDM) for inserting and withdrawing control rods into a reactor core, is capable of independently and sequentially positioning two sets of control rods with a single motor stator and rotor. The CRDM disclosed can control more than one control rod lead screw without incurring a substantial increase in the size of the mechanism
Characterization of Radiation Hardened Bipolar Linear Devices for High Total Dose Missions
McClure, Steven S.; Harris, Richard D.; Rax, Bernard G.; Thorbourn, Dennis O.
2012-01-01
Radiation hardened linear devices are characterized for performance in combined total dose and displacement damage environments for a mission scenario with a high radiation level. Performance at low and high dose rate for both biased and unbiased conditions is compared and the impact to hardness assurance methodology is discussed.
Few-photon Non-linearities in Nanophotonic Devices for Quantum Information Technology
Nysteen, Anders
In this thesis we investigate few-photon non-linearities in all-optical, on-chip circuits, and we discuss their possible applications in devices of interest for quantum information technology, such as conditional two-photon gates and single-photon sources. In order to propose efficient devices...... the scattered photons. Even though the non-linearity also alters the pulse spectrum due to a four-wave mixing process, we demonstrate that input pulses with a Gaussian spectrum can be mapped to the output with up to 80 % fidelity. Using two identical two-level emitters, we propose a setup for a deterministic...... by the capturing process. Semiconductor quantum dots (QDs) are promising for realizing few-photon non-linearities in solid-state implementations, although coupling to phonon modes in the surrounding lattice have significant influence on the dynamics. By accounting for the commonly neglected asymmetry between...
Design changes of device to investigation of alloys linear contraction and shrinkage stresses
J. Mutwil
2009-07-01
Full Text Available Some design changes in device elaborated by author to examination of linear contraction and shrinkage stresses progress of metals and alloys during– and after solidification have been described. The introduced changes have been focused on design of closing of shrinkage test rod mould. The introduced changes have been allowed to simplify a mounting procedure of thermocouples measuring a temperature of the shrinkage rod casting (in 6 points. Exemplary investigation results of linear contraction and shrinkage stresses development in Al-Si13.5% alloy have been presented.
Bodin, H. A.B.; Green, T. S.; Newton, A. A.; Niblett, G. B.F.; Reynolds, J. A. [United Kingdom Atomic Energy Authority, Culham Laboratory, Abingdon, Berks. (United Kingdom)
1966-04-15
This paper describes the application of a fast megajoule capacitor bank to the study of plasma production and confinement in the theta-pinch configuration. Deuterium gas at a pressure in the range 10 to 50 mTorr is pre-ionized by a transient axial current and subsequently compressed by a sinusoidal magnetic field with a peak value of 76 kG and a half-period of 12 {mu}s. The single-turn coil used in the experiment is 200 cm long and 10 cm in diameter. Lateral drift of the plasma to the walls of the discharge tube has been avoided by reduction of the curvature of confining lines of magnetic force using a parallel strip transmission line between the coil and collector. The origin of a low-amplitude circular motion of the plasma about the central equilibrium axis, the so-called wobble phenomenon, is discussed. The general properties of the discharge have been analysed by comparing the measured values of electron temperature, plasma diamagnetism, radial density distribution and neutron yield with numerical predictions using the Hain-Roberts hydromagnetic code. The rate of axial plasma loss has been determined by means of a wide variety of techniques. These include optical interferometry to measure the total number of trapped particles, an analysis of continuum emission in the visible spectrum to give the line density as a function of axial position, and miniature piezo-electric pressure probes to estimate the size of the loss aperture. The results show that the plasma is subject to magnetic field diffusion in the early stages and to cooling of the electrons either by impurity radiation or by thermal conduction along the field lines. The consequent depression of the plasma {beta} to a value about 0.5 at peak field enlarges the magnetic apertures at the ends of the coil and thus leads to axial escape of plasma. .The main problems for the future are therefore the development of a pre-heat system to give a higher temperature plasma at a {beta} of near unity, and the
H. Vazquez-Leal
2014-01-01
Full Text Available We present a homotopy continuation method (HCM for finding multiple operating points of nonlinear circuits composed of devices modelled by using piecewise linear (PWL representations. We propose an adaptation of the modified spheres path tracking algorithm to trace the homotopy trajectories of PWL circuits. In order to assess the benefits of this proposal, four nonlinear circuits composed of piecewise linear modelled devices are analysed to determine their multiple operating points. The results show that HCM can find multiple solutions within a single homotopy trajectory. Furthermore, we take advantage of the fact that homotopy trajectories are PWL curves meant to replace the multidimensional interpolation and fine tuning stages of the path tracking algorithm with a simple and highly accurate procedure based on the parametric straight line equation.
Observation of a current-limited double layer in a linear turbulent-heating device
Inuzuka, H.; Torii, Y.; Nagatsu, M.; Tsukishima, T.
1985-01-01
Time- and space-resolved measurements of strong double layers (DLs) have been carried out for the first time on a linear turbulent-heating device, together with those of fluctuation spectra and precise current measurements. A stable stong DL is formed even when the electric current through the DL is less than the so-called Bohm value. Discussion of the formation and decay processes is given, indicating a transition from an ion-acoustic DL to a monotonic DL
Linear motion device and method for inserting and withdrawing control rods
Smith, J.E.
Disclosed is a linear motion device and more specifically a control rod drive mechanism (CRDM) for inserting and withdrawing control rods into a reactor core. The CRDM and method disclosed is capable of independently and sequentially positioning two sets of control rods with a single motor stator and rotor. The CRDM disclosed can control more than one control rod lead screw without incurring a substantial increase in the size of the mechanism.
A new linear plasma device for the study of plasma waves in the electron magnetohydrodynamics regime
Joshi, Garima; Ravi, G.; Mukherjee, S.
2018-06-01
A new, user-friendly, linear plasma device has been developed in our laboratory where a quiescent (Δ n/n ≈ 1%), low temperature (1-10 eV), pulsed (3-10 ms) plasma can be produced over a large uniform region of 30-40 cm diameter and 40 cm length. Salient features of the device include the flexibility of tuning the plasma density in the range of 10^{10} to 10^{12} cm^{-3} and capability of scanning the plasma and field parameters in two dimensions with a precision of electromagnetic field parameters by miniature magnetic probes and Rogowski coils. The plasma produced is uniform and essentially unbounded for performing experiments on waves and turbulence. The whole device can be operated single-handedly by undergraduate or graduate students. The device can be opened, serviced, new antennas/probes installed and ready for operation in a matter of hours. Some results on the excitation of electromagnetic structures in the context of electron magnetohydrodynamics (EMHD) are also presented to demonstrate the suitability of the device for carrying out such experiments.
Oscillatory device for use with linear tribometer, for tribological evaluation of biomaterials
Athayde, J. N.; Siqueira, C. J. M.; Kuromoto, N. K.; Cambraia, H. N.
2017-07-01
Orthopedic implants still have limitations regarding their durability, despite being in use for over fifty years. Particles arising from wear due to the relative motion of their surfaces remain responsible for aseptic failure. This paper presents a device to be coupled with a reciprocal linear tribometer to reproduce the ex vivo wear of biomaterials, allowing the measurement of force and coefficient of friction. The device consists of a structure connected to the tribometer that transforms its reciprocal linear motion into one that is oscillatory for the mechanical assembly that contains the samples to test the desired biomaterials. The tribological pair used for testing consisted of Ultra High Molecular Weight Polyethylene (UHMWPE) in conjunction with the austenitic stainless steel AISI 316L in dry lubrication. The results showed that the values of the coefficient of friction in the linear mode and oscillatory mode and the UHMWPE life curve in the oscillatory mode were consistent with those cited in the literature for tests in a dry lubrication environment. Moreover, the UHMWPE sample life curve showed a reduction in the wear rate that can be explained by the preponderance of a wear mechanism over the others. The volumetric wear showed an increase with the number of cycles.
Characterization of high flux magnetized helium plasma in SCU-PSI linear device
Xiaochun, MA; Xiaogang, CAO; Lei, HAN; Zhiyan, ZHANG; Jianjun, WEI; Fujun, GOU
2018-02-01
A high-flux linear plasma device in Sichuan University plasma-surface interaction (SCU-PSI) based on a cascaded arc source has been established to simulate the interactions between helium and hydrogen plasma with the plasma-facing components in fusion reactors. In this paper, the helium plasma has been characterized by a double-pin Langmuir probe. The results show that the stable helium plasma beam with a diameter of 26 mm was constrained very well at a magnetic field strength of 0.3 T. The core density and ion flux of helium plasma have a strong dependence on the applied current, magnetic field strength and gas flow rate. It could reach an electron density of 1.2 × 1019 m-3 and helium ion flux of 3.2 × 1022 m-2 s-1, with a gas flow rate of 4 standard liter per minute, magnetic field strength of 0.2 T and input power of 11 kW. With the addition of -80 V applied to the target to increase the helium ion energy and the exposure time of 2 h, the flat top temperature reached about 530 °C. The different sizes of nanostructured fuzz on irradiated tungsten and molybdenum samples surfaces under the bombardment of helium ions were observed by scanning electron microscopy. These results measured in the SCU-PSI linear device provide a reference for International Thermonuclear Experimental Reactor related PSI research.
Ng, Jason Clement
Femtosecond laser processing is a flexible, three-dimensional (3D) fabrication technique used to make integrated low-loss photonic devices in fused silica. My work expanded the suite of available optical devices through the design and optimization of linear optical components such as low-loss (70-nm spectral window. My work further complemented femtosecond laser processing with the development of nonlinear device capabilities. While thermal poling is a well known process, significant challenges had restricted the development of nonlinear devices in fused silica. The laser writing process would erase the induced nonlinearity (erasing) while a written waveguide core acted as a barrier to the thermal poling process (blocking). Using second harmonic (SH) microscopy, the effectiveness of thermal poling on laser-written waveguides was systematically analyzed leading to the technique of "double poling", which effectively overcomes the two challenges of erasing and blocking. In this new process the substrate is poled before and after waveguide writing to restore the induced nonlinearity within the vicinity of the waveguide to enable effective poling for inducing a second-order nonlinearity (SON) in fused silica. A new flexible, femtosecond laser based erasure process was also developed to enable quasi-phase matching and to form arbitrarily chirped gratings. Following this result, second harmonic generation (SHG) in a quasiphase-matched (QPM) femtosecond laser written waveguide device was demonstrated. SHG in a chirped QPM structure was also demonstrated to illustrate the flexibility of the femtosecond laser writing technique. These are the first demonstration of frequency doubling in an all-femtosecond-laser-written structure. A maximum SHG conversion efficiency of 1.3 +/- 0.1x10 -11/W-cm-2 was achieved for the fundamental wavelength of 1552.8 nm with a phase-matching bandwidth of 4.4 nm for a 10.0-mm-long waveguide. For a shorter sample, an effective SON of chi(2) = 0
Analytic treatment of distributions of lithium neutrals and ions in linear devices
Chung, Kyu-Sun, E-mail: kschung@hanyang.ac.kr [Department of Electrical Engineering, Hanyang University, Seoul (Korea, Republic of); Hirooka, Yoshi; Ashikawa, Naoko [National Institute for Fusion Science, Toki (Japan); Cho, Soon Gook; Choi, Heung Gyoon; Kang, In Je [Department of Electrical Engineering, Hanyang University, Seoul (Korea, Republic of); Tsuchiya, Hayato [National Institute for Fusion Science, Toki (Japan)
2017-06-15
Neutral lithium (Li) has been used for the mitigation of heat flux to the plasma facing components and for the control of hydrogen of fusion plasmas. Radial and axial variations of densities of Li neutrals and ions are obtained analytically for a cylindrical chamber by assuming the classical diffusion with or without the magnetic field (B). Neutrals and ions without B can be expressed as a linear combination of the modified Bessel functions of order zero (I{sub 0} and K{sub 0}), while ions with B are to be expressed as the square root of them. Analytical solutions of Li neutral densities with Dirichlet and Neumann boundary conditions are compared to those using Monte Carlo simulation and experimental values of the LIGHT-1 (Lithium Injection Gettering of Hydrogen and its Transport experiments) device. Proper combinations of the relaxation length and size of the source would produce well fitted profiles similar to those observed experimentally and those using Monte Carlo codes.
[A capillary blood flow velocity detection system based on linear array charge-coupled devices].
Zhou, Houming; Wang, Ruofeng; Dang, Qi; Yang, Li; Wang, Xiang
2017-12-01
In order to detect the flow characteristics of blood samples in the capillary, this paper introduces a blood flow velocity measurement system based on field-programmable gate array (FPGA), linear charge-coupled devices (CCD) and personal computer (PC) software structure. Based on the analysis of the TCD1703C and AD9826 device data sheets, Verilog HDL hardware description language was used to design and simulate the driver. Image signal acquisition and the extraction of the real-time edge information of the blood sample were carried out synchronously in the FPGA. Then a series of discrete displacement were performed in a differential operation to scan each of the blood samples displacement, so that the sample flow rate could be obtained. Finally, the feasibility of the blood flow velocity detection system was verified by simulation and debugging. After drawing the flow velocity curve and analyzing the velocity characteristics, the significance of measuring blood flow velocity is analyzed. The results show that the measurement of the system is less time-consuming and less complex than other flow rate monitoring schemes.
A new linear plasma device for various edge plasma studies at SWIP
Xu, Min; Zheng, Pengfei; Tynan, George; Che, Tong; Wang, Zhanhui; Guo, Dong; Wei, Ran
2017-10-01
To facilitate the plasma-material interactions (PMI) studies, Southwestern Institute of Physics (SWIP) has constructed a linear plasma device. It is comprised of a source chamber (Φ 0.4 m), a target chamber (Φ 0.9 m), 15 magnets with different sizes, and power supplies with the total power of a few hundred kilowatts, etc. A maximum magnetic field of 0.3 Tesla along the axial direction can be produced. The current of each of the 15 magnets can be independently controlled. More than 60 ports are available for diagnostics, with the sizes vary from Φ 50 mm to Φ 150 mm. Rectangular ports of 190 mm × 270 mm are also available. 12 ports looking at the sample holder are specially designed for ion beam injection, of which the axes are 25 to the chamber axis. The device is equipped with a LaB6 hot cathode plasma source, which is able to generate steady-state H/D/He plasmas with a diameter of Φ 100 mm, density of 1x1019 /m3 , and a particle flux of 1022 1023 n/m2 .s. The electron temperature is usually a few eV. Further, a Helicon RF plasma source is also planned for plasma transport studies. Int'l Sci & Tech Cooperation Program of China (No. 2015DFA61760).
ERO modeling of Cr sputtering in the linear plasma device PSI-2
Eksaeva, A.; Borodin, D.; Kreter, A.; Nishijima, D.; Pospieszczyk, A.; Schlummer, T.; Ertmer, S.; Terra, A.; Unterberg, B.; Kirschner, A.; Romazanov, J.; Brezinsek, S.; Rasinski, M.; Henderson, S.; O'Mullane, M.; Summers, H.; Bluteau, M.; Marenkov, E.
2017-12-01
The prediction of the first wall deterioration and possible plasma contamination by impurities is a high priority task for ITER. 3D Monte-Carlo code ERO is a tool for modeling of eroded impurity transport and spectroscopy in plasma devices useful for experiment interpretation. Chromium (Cr) is a fusion-relevant reactor wall element (e.g. component of RAFM steels expected for use in DEMO). Linear plasma devices including PSI-2 are effective tools for investigations of plasma-surface interaction effects, allowing continuous plasma operation and good control over irradiation parameters. Experiments on Cr sputtering were conducted at PSI-2. In these experiments the Cr erosion was measured by three techniques: mass loss of the sample, quartz micro-balance of deposited impurities at a distance from it and optical emission spectroscopy. Experiments were modeled with the 3D Monte-Carlo code ERO, previously validated by application to similar experiments with tungsten (W). The simulations are demonstrated to reproduce the main experimental outcomes proving the quality of the sputtering data used. A significant focuses of the paper is the usage and validation of atomic data (resent metastable-resolved dataset from ADAS) for interpretation of Cr spectroscopy. Initial population of quasi-metastable state was fitted by matching the modeling with the experimental line intensity profiles.
Power accounting of plasma discharges in the linear device Proto-MPEX
Showers, M.; Piotrowicz, P. A.; Beers, C. J.; Biewer, T. M.; Caneses, J.; Canik, J.; Caughman, J. B. O.; Donovan, D. C.; Goulding, R. H.; Lumsdaine, A.; Kafle, N.; Owen, L. W.; Rapp, J.; Ray, H.
2018-06-01
Plasma material interaction (PMI) studies are crucial to the successful development of future fusion reactors. Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a prototype design for the MPEX, a steady-state linear device being developed to study PMI. The primary purpose of Proto-MPEX is developing the plasma heating source concepts for MPEX. A power accounting study of Proto-MPEX works to identify machine operating parameters that could improve its performance, thereby increasing its PMI research capabilities, potentially impacting the MPEX design concept. To build a comprehensive power balance, an analysis of the helicon region has been performed implementing a diagnostic suite and software modeling to identify mechanisms and locations of heat loss from the main plasma. Of the 106.3 kW of input power, up to 90.5% of the power has been accounted for in the helicon region. When the analysis was extended to encompass the device to its end plates, 49.2% of the input power was accounted for and verified diagnostically. Areas requiring further diagnostic analysis are identified. The required improvements will be implemented in future work. The data acquisition and analysis processes will be streamlined to form a working model for future power balance studies of Proto-MPEX. ).
Bevilacqua, F.
1979-01-01
The components of the additional gripper devices with magnetically operated finger-shaped latches are separated from the also magnetically operated latches of the linear drive mechanisms in order to avoid common-mode failures when fast shutdown is required. Only part of the safety rods are held by the additional gripping devices in the withdrawn position. There is provided for recording elements indicating positively which one of the safety locks is gearing with the control rods. At the upper end of each control rod there is a coupling head held by electromagnetically operated locking devices in the withdrawn position, if control power is available. (DG) [de
Silicon Photonics: All-Optical Devices for Linear and Nonlinear Applications
Driscoll, Jeffrey B.
Silicon photonics has grown rapidly since the first Si electro-optic switch was demonstrated in 1987, and the field has never grown more quickly than it has over the past decade, fueled by milestone achievements in semiconductor processing technologies for low loss waveguides, high-speed Si modulators, Si lasers, Si detectors, and an enormous toolbox of passive and active integrated devices. Silicon photonics is now on the verge of major commercialization breakthroughs, and optical communication links remain the force driving integrated and Si photonics towards the first commercial telecom and datacom transceivers; however other potential and future applications are becoming uncovered and refined as researchers reveal the benefits of manipulating photons on the nanoscale. This thesis documents an exploration into the unique guided-wave and nonlinear properties of deeply-scaled high-index-contrast sub-wavelength Si waveguides. It is found that the tight confinement inherent to single-mode channel waveguides on the silicon-on-insulator platform lead to a rich physics, which can be leveraged for new devices extending well beyond simple passive interconnects and electro-optic devices. The following chapters will concentrate, in detail, on a number of unique physical features of Si waveguides and extend these attributes towards new and interesting devices. Linear optical properties and nonlinear optical properties are investigated, both of which are strongly affected by tight optical confinement of the guided waveguide modes. As will be shown, tight optical confinement directly results in strongly vectoral modal components, where the electric and magnetic fields of the guided modes extend into all spatial dimensions, even along the axis of propagation. In fact, the longitudinal electric and magnetic field components can be just as strong as the transverse fields, directly affecting the modal group velocity and energy transport properties since the longitudinal fields
Experimental study of ultra-low q discharges in the linear Extrap L1 device
Brunsell, P.; Karlsson, Per.
1991-01-01
Linear pinch discharges with combined octupole and longitudinal magnetic fields are experimentally studied in the Extrap L1 device. Plasma currents are around I p =10 kA, plasma temperautres are up to T e =50 eV and plasma densities are of the order of n=5x10 21 m -3 . The plasma equilibria are in the ultra-low q (ULQ) regime corresponding to operation with plasma currents in excess of the Kruskal-Shafranov stability limit (q less than 1). The plasma current exhibits the typical time behaviour seen in toroidal ULQ experiments; the unstable setting up phase and the step-wise decay with current levels corresponding to q-values in windows between rational values. Longitudinal plasma current generated by radial plasma diffusion is seen, with amplitudes up to 30% of the externally driven current during the initial phase of the discharge. The effect of the octupole magnetic field on the ULQ confinement is investigated. The plasma temperature increases by more than a factor of two, for the optimum octupole rod current (I v =I p ), compared to the case without octupole field. A plasma current limitation for stable operation corresponding to q bigger than 1/2 is observed, excepts for low axial magnetic field strength. In the low axial field regime, the octupole field alone provides sufficient stabilization for operation with q less than 1/2. Plasma density and temperature both increase linearly with applied axial magnetic field. The density shows a strong, approximately exponential, dependence on discharge voltage. (au)
Validation study of a drift-wave turbulence model for CSDX linear plasma device
Vaezi, P.; Holland, C.; Thakur, S. C.; Tynan, G. R.
2017-09-01
A validation study of self-regulating drift-wave turbulence/zonal flow dynamics in the Controlled Shear Decorrelation Experiment linear plasma device using Langmuir probe synthetic diagnostics is presented in this paper. We use a set of nonlocal 3D equations, which evolve density, vorticity, and electron temperature fluctuations, and include proper sheath boundary conditions. Nonlinear simulations of these equations are carried out using BOUndary Turbulence (BOUT++) framework. To identify the dominant parametric dependencies of the model, a linear growth rate sensitivity analysis is performed using input parameter uncertainties, which are taken from the experimental measurements. For the direct comparison of nonlinear simulation results to experiment, we use synthetic Langmuir probe diagnostics to generate a set of synthetic ion saturation current and floating potential fluctuations. In addition, comparisons of azimuthal velocities determined via time-delay estimation, and nonlinear energy transfer are shown. We observe a significant improvement of model-experiment agreement relative to the previous 2D simulations. An essential component of this improved agreement is found to be the effect of electron temperature fluctuations on floating potential measurements, which introduces clear amplitude and phase shifts relative to the plasma potential fluctuations in synthetically measured quantities, where the simulations capture the experimental measurements in the core of plasma. However, the simulations overpredict the fluctuation levels at larger radii. Moreover, systematic simulation scans show that the self-generated E × B zonal flows profile is very sensitive to the steepening of density equilibrium profile. This suggests that evolving both fluctuations and equilibrium profiles, along with the inclusion of modest axial variation of radial profiles in the model are needed for further improvement of simulation results against the experimental measurements.
Studies of radiation hardness of MOS devices for application in a linear collider vertex detector
Wei, Qingyu
2008-10-17
The proposed International Linear Collider (ILC) together with the Large Hadron Collider (LHC) at CERN serve as a combined tool to explore the mysteries of the universe: the former is a precision machine and the latter can be considered as a finding machine. The key component of the ILC is the vertex detector that should be placed as close as possible to the Interaction Point (IP) and has better radiation tolerance against the dominant electron-positron pair production background from beam-beam interactions. A new generation of MOS-type Depleted-Field-Effect Transistor (MOSDEPFET) active pixel detectors has been proposed and developed by Semiconductor Labor Munich for Physics and for extraterrestrial Physics in order to meet the requirements of the vertex detector at the ILC. Since all MOS devices are susceptible to ionizing radiation, the main topic is focused on the radiation hardness of detectors, by which a series of physical processes are analyzed: e.g. surface damage due to ionizing radiation as well as damage mechanisms and their associated radiation effects. As a consequence, the main part of this thesis consists of a large number of irradiation experiments and the corresponding discussions. Finally, radiation hardness of the detectors should be improved through a set of concluded experiences that are based on a series of analysis of the characteristic parameters using different measurement techniques. The feasibility of the MOSDEPFET-based vertex detector is, therefore, predicted at ILC. (orig.)
Studies of radiation hardness of MOS devices for application in a linear collider vertex detector
Wei, Qingyu
2008-01-01
The proposed International Linear Collider (ILC) together with the Large Hadron Collider (LHC) at CERN serve as a combined tool to explore the mysteries of the universe: the former is a precision machine and the latter can be considered as a finding machine. The key component of the ILC is the vertex detector that should be placed as close as possible to the Interaction Point (IP) and has better radiation tolerance against the dominant electron-positron pair production background from beam-beam interactions. A new generation of MOS-type Depleted-Field-Effect Transistor (MOSDEPFET) active pixel detectors has been proposed and developed by Semiconductor Labor Munich for Physics and for extraterrestrial Physics in order to meet the requirements of the vertex detector at the ILC. Since all MOS devices are susceptible to ionizing radiation, the main topic is focused on the radiation hardness of detectors, by which a series of physical processes are analyzed: e.g. surface damage due to ionizing radiation as well as damage mechanisms and their associated radiation effects. As a consequence, the main part of this thesis consists of a large number of irradiation experiments and the corresponding discussions. Finally, radiation hardness of the detectors should be improved through a set of concluded experiences that are based on a series of analysis of the characteristic parameters using different measurement techniques. The feasibility of the MOSDEPFET-based vertex detector is, therefore, predicted at ILC. (orig.)
Pease, R.L.; Brown, D.B.; Cohn, L.
1997-01-01
A hardness assurance test approach has been developed for bipolar linear circuits and devices in space. It consists of a screen for dose rate sensitivity and a characterization test method to develop the conditions for a lot acceptance test at high dose rate
Field reversal experiments (FRX)
Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.
1978-01-01
The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10 15 cm -3 . After the plasma reaches equilibrium, the RFC remains stable for up to 30 μs followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value
Field reversal experiments (FRX)
Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.
1979-01-01
The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centres the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFCs with a major radius R=2-6cm, a minor radius a approximately 2cm, and a total length l approximately 35cm. The observed temperatures are Tsub(e) approximately 100eV and Tsub(i)=150-350eV with a peak density n approximately 2x10 15 cm -3 . After the plasma has reached equilibrium, the RFC remains stable for up to 30μs, followed by the rapid growth of the rotational m=2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behaviour of the m=2 mode agrees qualitatively with the theoretically predicted instability for rotational velocities exceeding some critical value. (author)
Field reversal experiments (FRX). [Equilibrium, confinement, and stability
Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.
1978-01-01
The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10/sup 15/ cm/sup -3/. After the plasma reaches equilibrium, the RFC remains stable for up to 30 ..mu..s followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value.
American Society for Testing and Materials. Philadelphia
2005-01-01
1.1 This test method determines the degree of linearity of a photovoltaic device parameter with respect to a test parameter, for example, short-circuit current with respect to irradiance. 1.2 The linearity determined by this test method applies only at the time of testing, and implies no past or future performance level. 1.3 This test method applies only to non-concentrator terrestrial photovoltaic devices. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Morlanes, Tomas; de la Pena, Jose L.; Sanchez-Brea, Luis M.; Alonso, Jose; Crespo, Daniel; Saez-Landete, Jose B.; Bernabeu, Eusebio
2005-07-01
In this work, an optoelectronic device that provides the absolute position of a measurement element with respect to a pattern scale upon switch-on is presented. That means that there is not a need to perform any kind of transversal displacement after the startup of the system. The optoelectronic device is based on the process of light propagation passing through a slit. A light source with a definite size guarantees the relation of distances between the different elements that constitute our system and allows getting a particular optical intensity profile that can be measured by an electronic post-processing device providing the absolute location of the system with a resolution of 1 micron. The accuracy of this measuring device is restricted to the same limitations of any incremental position optical encoder.
Implosion measurements in a high voltage, large diameter, medium density theta pinch
Henins, I.; Hammel, J.E.; Jarboe, T.E.; Marshall, J.; Sherwood, A.R.
1975-01-01
Extensive sets of density measurements were obtained for two preionization levels with other parameters held constant (B = 0.5 T, n 0 = 4.8 x 10 14 cm -3 , E/sub theta/ = 1 kV/cm). The gross features of the implosion are similar in the two cases, but the density front is double-peaked for the higher preionization case. Generally, the particles move ahead of the driving magnetic field front, but some are also within this front. After reaching the axis the imploding plasma is observed to move outward again through the magnetic field in a manner suggesting anomalous transport. The particles stop at the outer radii. The total number of particles increases during the implosion and thereafter remains about constant. (auth)
Experiments of spheromak and reversed field configuration in 2m theta pinch
Nogi, Y.; Shimamura, S.; Ogura, H.; Osanai, Y.; Saito, K.; Shiina, S.; Yoshimura, H.
1981-01-01
Since the z-current produces the paramagnetic field near the electrodes, the spheromak formation is more difficult in the straight bias field. In order to help the reconnection at the coil ends, the cusp bias coils are added to both ends of the straight coil. Then the spheromak configuration is formed and the plasma is confined for 5 to 10 μs. On the other hand, the RFC continues for about 30 μs in case of the straight bias field. The confinement time is limited by the rotational instability. Although the start time of the instability is not clear, the elongation of the plasma is detected in 15 to 20 μs after the RFC is formed. The period of the rotation is slightly different every shot. Detailed study of the instability is being pursued
Environmental and technological implications of a theta-pinch fusion power plant
Coultas, T.A.; Burke, R.J.; Krakowski, R.A.
1974-01-01
The environmental effects of this conceptual design were evaluated and found to be little different from other electrical power plants in most regards. Exceptions include a very small release of tritium, a low-hazard isotope, and relatively large amounts of radioactive material which must be either stored on site for eventual reprocessing or permanently discarded. These radioactive materials are nonvolatile and should not pose a difficult disposal problem, although some of the material may remain radioactive for hundreds of years. Natural resources required to build and operate the reference plant are not excessive except perhaps in the case of niobium and beryllium. The accident, sabotage, etc., problems of the plant are very minimal and although accidents can be postulated which would be inconvenient and costly within the plant, the probability of sizable impact on the surroundings is so as to be incredible
Energy storage, compression, and switching in a theta-pinch fusion test reactor
Thomassen, K.I.
1976-01-01
A new 488 MJ superconducting magnetic energy storage and transfer system is being proposed for a Scyllac Fusion Test Reactor. The 1280 module system uses vacuum interrupters to switch 26 kA storage currents in 0.7 ms through a capacitive transfer circuit at 60 kV to the compression coils in the machine. Many of the components of the system have been built and tested and a prototype section of the machine is planned. Prototype coils with 381 kJ at 26 kA currents will be built by industry using advanced superconducting wire. The wire uses a Cu and Cu--Ni matrix around filaments of Nb--Ti to minimize eddy current losses. These wires are presently used in a 10 kA braided conductor for 300 kJ pre-prototype coils, and can withstand field changes of approximately 10 7 gauss/sec without inducing normal transitions. Three such 300 kJ coils are being constructed in industry for the LASL program
Flux trapping during field reversal in a field reversed theta pinch
Milroy, R.D.; Hoffman, A.L.; Slough, J.T.; Harding, D.G.
1983-01-01
In this paper we present new results from both numerical and experimental studies of the formation of the conducting sheath near the tube wall and its effectiveness in trapping bias flux during field reversal
Keene, Scott T.; Melianas, Armantas; Fuller, Elliot J.; van de Burgt, Yoeri; Talin, A. Alec; Salleo, Alberto
2018-06-01
Neuromorphic devices are becoming increasingly appealing as efficient emulators of neural networks used to model real world problems. However, no hardware to date has demonstrated the necessary high accuracy and energy efficiency gain over CMOS in both (1) training via backpropagation and (2) in read via vector matrix multiplication. Such shortcomings are due to device non-idealities, particularly asymmetric conductance tuning in response to uniform voltage pulse inputs. Here, by formulating a general circuit model for capacitive ion-exchange neuromorphic devices, we show that asymmetric nonlinearity in organic electrochemical neuromorphic devices (ENODes) can be suppressed by an appropriately chosen write scheme. Simulations based upon our model suggest that a nonlinear write-selector could reduce the switching voltage and energy, enabling analog tuning via a continuous set of resistance states (100 states) with extremely low switching energy (~170 fJ · µm‑2). This work clarifies the pathway to neural algorithm accelerators capable of parallelism during both read and write operations.
Dzielski, John Edward
1988-01-01
Recent developments in the area of nonlinear control theory have shown how coordiante changes in the state and input spaces can be used with nonlinear feedback to transform certain nonlinear ordinary differential equations into equivalent linear equations. These feedback linearization techniques are applied to resolve two problems arising in the control of spacecraft equipped with control moment gyroscopes (CMGs). The first application involves the computation of rate commands for the gimbals that rotate the individual gyroscopes to produce commanded torques on the spacecraft. The second application is to the long-term management of stored momentum in the system of control moment gyroscopes using environmental torques acting on the vehicle. An approach to distributing control effort among a group of redundant actuators is described that uses feedback linearization techniques to parameterize sets of controls which influence a specified subsystem in a desired way. The approach is adapted for use in spacecraft control with double-gimballed gyroscopes to produce an algorithm that avoids problematic gimbal configurations by approximating sets of gimbal rates that drive CMG rotors into desirable configurations. The momentum management problem is stated as a trajectory optimization problem with a nonlinear dynamical constraint. Feedback linearization and collocation are used to transform this problem into an unconstrainted nonlinear program. The approach to trajectory optimization is fast and robust. A number of examples are presented showing applications to the proposed NASA space station.
A Detailed Analytical Study of Non-Linear Semiconductor Device Modelling
Umesh Kumar
1995-01-01
junction diode have been developed. The results of computer simulated examples have been presented in each case. The non-linear lumped model for Gunn is a unified model as it describes the diffusion effects as the-domain traves from cathode to anode. An additional feature of this model is that it describes the domain extinction and nucleation phenomena in Gunn dioder with the help of a simple timing circuit. The non-linear lumped model for SCR is general and is valid under any mode of operation in any circuit environment. The memristive circuit model for p-n junction diodes is capable of simulating realistically the diode’s dynamic behavior under reverse, forward and sinusiodal operating modes. The model uses memristor, the charge-controlled resistor to mimic various second-order effects due to conductivity modulation. It is found that both storage time and fall time of the diode can be accurately predicted.
Kirianenko, A; Maurice, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1963-07-01
The Castaing electronic probe micro-analyser makes possible static analysis at successive points. For two years this apparatus has been equipped by its constructor with an automatic device for surface scanning. In order to increase the micro-analyser's efficiency a 'linear' scan device has been incorporated making it possible to obtain semi-quantitative analyses very rapidly. (authors) [French] Le microanalyseur a sonde electronique de Castaing permet l'analyse statique en des points successifs. Depuis deux ans, cet appareil a ete equipe par son constructeur d'un dispositif de balayage automatique 'surface'. Afin d'augmenter l'efficacite du microanalyaeur, on a adapte un dispositif de balayage 'lineaire' qui permet d'obtenir tres rapidement des analyses semi-quantitative. (auteurs)
Nikolay Chernov
2018-01-01
Full Text Available The article considers linear algebra as an alternative mathematical tool of logic synthesis of digital structures to Boolean algebra and synthesis methods of digital electronic component base (ECB on its ground. The methods of solving the applied problems of logic synthesis are shown, including the expansion of an arbitrary logic function by means of monotonic functions. The proposed mathematical apparatus actually provides the creation of digital structures on the principles of analog circuitry. It can find application in the design of multivalued digital ECB, specialized system-on-chip and analog-digital sensors with current output. The examples of synthesis of the combinational and sequential two-valued and multivalued digital devices are given. In conclusion, the advantages of linear algebra in comparison with Boolean algebra are formulated.
Lundahl, P. Johan; Kitts, Catherine C.; Nordé n, Bengt
2011-01-01
This article presents a new design of flow-orientation device for the study of bio-macromolecules, including DNA and protein complexes, as well as aggregates such as amyloid fibrils and liposome membranes, using Linear Dichroism (LD) spectroscopy. The design provides a number of technical advantages that should make the device inexpensive to manufacture, easier to use and more reliable than existing techniques. The degree of orientation achieved is of the same order of magnitude as that of the commonly used concentric cylinders Couette flow cell, however, since the device exploits a set of flat strain-free quartz plates, a number of problems associated with refraction and birefringence of light are eliminated, increasing the sensitivity and accuracy of measurement. The device provides similar shear rates to those of the Couette cell but is superior in that the shear rate is constant across the gap. Other major advantages of the design is the possibility to change parts and vary sample volume and path length easily and at a low cost. © 2011 The Royal Society of Chemistry.
Jie, Cui; Lei, Chen; Peng, Zhao; Xu, Niu; Yi, Liu
2014-06-01
A broadband monolithic linear single pole, eight throw (SP8T) switch has been fabricated in 180 nm thin film silicon-on-insulator (SOI) CMOS technology with a quad-band GSM harmonic filter in integrated passive devices (IPD) technology, which is developed for cellular applications. The antenna switch module (ASM) features 1.2 dB insertion loss with filter on 2G bands and 0.4 dB insertion loss in 3G bands, less than -45 dB isolation and maximum -103 dB intermodulation distortion for mobile front ends by applying distributed architecture and adaptive supply voltage generator.
Cui Jie; Chen Lei; Liu Yi; Zhao Peng; Niu Xu
2014-01-01
A broadband monolithic linear single pole, eight throw (SP8T) switch has been fabricated in 180 nm thin film silicon-on-insulator (SOI) CMOS technology with a quad-band GSM harmonic filter in integrated passive devices (IPD) technology, which is developed for cellular applications. The antenna switch module (ASM) features 1.2 dB insertion loss with filter on 2G bands and 0.4 dB insertion loss in 3G bands, less than −45 dB isolation and maximum −103 dB intermodulation distortion for mobile front ends by applying distributed architecture and adaptive supply voltage generator. (semiconductor integrated circuits)
Potential formation in the plasma confinement region of a radio-frequency plugged linear device
Fujita, Hideki; Kumazawa, Ryuhei; Howald, A.M.; Okamura, Shoichi; Sato, Teruyuki; Adati, Keizo; Garner, H.R.; Nishimura, Kiyohiko.
1987-08-01
Plasma potential formation in an open-ended plasma confinement system with RF plugging (the RFC-XX-M device) is investigated. The plasma potential in the central confinement region is measured with a heavy ion beam probe system and potentials at the RF plug section are measured with multi-grid energy analyzers. The measured plasma potential is compared with that deduced from the generalized Pastukhov formula. Results show that the plasma potential develops as an ambipolar potential to equate ion and electron end losses. During RF plugging, electrons are heated by Landau damping, while ions are not heated since adiabatic conditions apply during ion plugging in this experiment. (author)
A linear two-layer model for flat-band shift in irradiated MOS devices
Churchill, J N; Holstrom, F E; Collins, T W [International Business Machines Corp., San Jose, Calif. (USA)
1976-04-01
A closed-form mathematical expression is derived for the flat-band shift as a function of gate bias during electron irradiation. The model assumes that the charge in the oxide consists of charged layers of variable thickness at each of the two interfaces, depending on voltage polarity and magnitude. The region of extreme linearity which has been observed by numerous investigators and which normally occurs for the relatively small values of gate bias voltages fits this closed-form solution. Analytical results compare favourably with data obtained from 500 to 700 A thick oxides and with other previously published data.
2D turbulence structure observed by a fast framing camera system in linear magnetized device PANTA
Ohdachi, Satoshi; Inagaki, S.; Kobayashi, T.; Goto, M.
2015-01-01
Mesoscale structure, such as the zonal flow and the streamer plays important role in the drift-wave turbulence. The interaction of the mesoscale structure and the turbulence is not only interesting phenomena but also a key to understand the turbulence driven transport in the magnetically confined plasmas. In the cylindrical magnetized device, PANTA, the interaction of the streamer and the drift wave has been found by the bi-spectrum analysis of the turbulence. In order to study the mesoscale physics directly, the 2D turbulence is studied by a fast-framing visible camera system view from a window located at the end plate of the device. The parameters of the plasma is the following; Te∼3eV, n ∼ 1x10 19 m -3 , Ti∼0.3eV, B=900G, Neutral pressure P n =0.8 mTorr, a∼ 6cm, L=4m, Helicon source (7MHz, 3kW). Fluctuating component of the visible image is decomposed by the Fourier-Bessel expansion method. Several rotating mode is observed simultaneously. From the images, m = 1 (f∼0.7 kHz) and m = 2, 3 (f∼-3.4 kHz) components which rotate in the opposite direction can be easily distinguished. Though the modes rotate constantly in most time, there appear periods where the radially complicated node structure is formed (for example, m=3 component, t = 142.5∼6 in the figure) and coherent mode structures are disturbed. Then, a new rotating period is started again with different phase of the initial rotation until the next event happens. The typical time interval of the event is 0.5 to 1.0 times of the one rotation of the slow m = 1 mode. The wave-wave interaction might be interrupted occasionally. Detailed analysis of the turbulence using imaging technique will be discussed. (author)
Zhang Jun; Guo Yu-Feng; Xu Yue; Lin Hong; Yang Hui; Hong Yang; Yao Jia-Fei
2015-01-01
A novel one-dimensional (1D) analytical model is proposed for quantifying the breakdown voltage of a reduced surface field (RESURF) lateral power device fabricated on silicon on an insulator (SOI) substrate. We assume that the charges in the depletion region contribute to the lateral PN junctions along the diagonal of the area shared by the lateral and vertical depletion regions. Based on the assumption, the lateral PN junction behaves as a linearly graded junction, thus resulting in a reduced surface electric field and high breakdown voltage. Using the proposed model, the breakdown voltage as a function of device parameters is investigated and compared with the numerical simulation by the TCAD tools. The analytical results are shown to be in fair agreement with the numerical results. Finally, a new RESURF criterion is derived which offers a useful scheme to optimize the structure parameters. This simple 1D model provides a clear physical insight into the RESURF effect and a new explanation on the improvement in breakdown voltage in an SOI RESURF device. (paper)
Design of a non-linear power take-off simulator for model testing of rotating wave energy devices
Lopes, M.F.P.; Henriques, J.C.C.; Lopes, Miguel C.; Gato, L.M.C. [IDMEC - Instituto de Engenharia Mecanica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Lisboa (Portugal); Dente Antonio [CIE3 - Center for Innovation in Electrical and Energy Engineering, Lisboa (Portugal)
2009-07-01
Eddy current brakes provide a versatile way of simulating the power take-off system (PTO) in the model testing of wave energy converters at small scale. These are based on the principle that a conductive material moving perpendicularly to a magnetic field generates a braking force proportional to its velocity. This was applied in the design of the PTO simulator of a bottom-hinged flap wave energy converter model, at 1/16 scale. The efforts put into the accurate dynamic simulation of the device led to the development of a controllable PTO simulator, which can be applied to other small scale rotating wave energy device models. A special power source was built to provide the required controllable current intensity to feed the magnetic field generating coils. Different non-linear damping PTO characteristic curves can be simulated by basing the current control on real-time velocity measurement. The calibration of the system was done by connecting the device to a constant rotating speed motor and measuring the resistent torque produced by the PTO with a torquemeter for different values of current intensity through the coils.
Linear and nonlinear ion beam instabilities in a double plasma device
Lee, S.G.; Diebold, D.; Hershkowitz, N.
1994-01-01
Ion beam instabilities in the double plasma device DOLI-1 were found to be quite sensitive to the difference between the source and target chamber plasma potentials when those potentials were within an electron temperature T e /e or so of each other. When the target chamber plasma potential of DOLI-1 was ≤ T e /e more positive than the source chamber plasma potential, a global ion beam-ion beam instability was observed. On the other hand, when the maximum target potential was between approximately 0.5 T e /e and 2.0 T e /e below the source potential, an ion-ion beam instability and a soliton associated with it were observed. This soliton is unique in that it is not launched but rather is self generated by the plasma and beam. When the target potential was less than source potential by more than two or so T e /e, the plasma was quite quiescent, which allowed small amplitude wave packet launched by Langmuir probe to be detected
Kamali, Mohammadreza; Jazayeri, Seyed Ali [K. N.Toosi University of Technology, Tehran (Iran, Islamic Republic of); Najafi, Farid [University of Guilan, Rasht (Iran, Islamic Republic of); Kawashima, Kenji [Tokyo Medical and Dental University, Tokyo (Japan); Kagawa, Toshiharu [Tokyo Institute of Technology, Tokyo (Japan)
2016-05-15
This paper introduces a new nozzle-flapper valve with isothermal chamber using piezoelectric actuator. It controls the pressure and flow rate simply, effectively and separately. The proposed valve uses isothermal chamber presenting practical isothermal condition due to its large heat transfer interfaces filled by metal wool. The valve uses stacked type piezoelectric actuator with unique advantages. By using this valve, a simple method has been fulfilled to control flow rate or pressure of ideal gases in a pneumatic actuators. Experimental results demonstrated applications of the proposed valve to control either pressure or flow rate in pneumatic circuits. This valve can be also used in the pilot stage valve to actuate the main stage of a much bigger pneumatic valve. Designated structure contains only one pressure sensor installed on the isothermal control chamber, capable of controlling both pressure and flow rate. The desired output mass flow rate of the valve is controlled by the pressure changes during positioning of piezoelectric actuator at proper position. The proposed valve can control steady and unsteady oscillatory flow rate and pressure effectively, using nonlinear control method such as feedback linearization approach. Its effectiveness is demonstrated and validated through simulation and experiments.
Three-dimensional linear peeling-ballooning theory in magnetic fusion devices
Weyens, T., E-mail: tweyens@fis.uc3m.es; Sánchez, R.; García, L. [Departamento de Física, Universidad Carlos III de Madrid, Madrid 28911 (Spain); Loarte, A.; Huijsmans, G. [ITER Organization, Route de Vinon sur Verdon, 13067 Saint Paul Lez Durance (France)
2014-04-15
Ideal magnetohydrodynamics theory is extended to fully 3D magnetic configurations to investigate the linear stability of intermediate to high n peeling-ballooning modes, with n the toroidal mode number. These are thought to be important for the behavior of edge localized modes and for the limit of the size of the pedestal that governs the high confinement H-mode. The end point of the derivation is a set of coupled second order ordinary differential equations with appropriate boundary conditions that minimize the perturbed energy and that can be solved to find the growth rate of the perturbations. This theory allows of the evaluation of 3D effects on edge plasma stability in tokamaks such as those associated with the toroidal ripple due to the finite number of toroidal field coils, the application of external 3D fields for elm control, local modification of the magnetic field in the vicinity of ferromagnetic components such as the test blanket modules in ITER, etc.
LASL Controlled Thermonuclear Research Program. Progress report, January--December 1976
Thomas, K.S.
1978-03-01
This annual progress report is divided into the following sections: (1) Scyllac feedback sector experiments, (2) staged theta-pinch program, (3) toroidal reverse-field pinch, (4) Scylla IV-P linear theta-pinch experiments, (5) gun injection experiment, (6) Scylla I-C, laser-plasma interaction studies, (7) field reversal theta pinch, (8) Implosion Heating Experiment, (9) experimental plasma physics, (10) plasma diagnostics, (11) high-beta tokamak, (12) theory, (13) computers, (14) engineering, (15) magnetic energy transfer and storage, (16) magnetic confinement systems studies, and (17) intense neutron source facility
Laguardia, L., E-mail: laguardia@ifp.cnr.it [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Caniello, R.; Cremona, A. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Dellasega, D. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Politecnico di Milano, Dipartimento di Energia, Milan (Italy); Dell’Era, F.; Ghezzi, F.; Gittini, G.; Granucci, G.; Mellera, V.; Minelli, D.; Pallotta, F. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Passoni, M. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Politecnico di Milano, Dipartimento di Energia, Milan (Italy); Ricci, D.; Vassallo, E. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy)
2015-08-15
In this work results of the first D{sub 2}/N{sub 2} experiments in GyM, a linear device able to produce plasmas of interest for the ITER divertor (n{sub e} 5 ⋅ 10{sup 10} cm{sup −3}, Te 5 eV, ion flux 3–5 ⋅ 10{sup 20} m{sup −2}s{sup −1}) are presented. Plasmas simulating a N-seeding scenario have been performed to evaluate ammonia formation and its effect on exposed W coatings. The presence of ND emission lines in the plasma can be correlated with the formation of ammonia, further directly detected and quantified by chromatography analysis of the exhaust. Four different W specimens were exposed in GyM to a plasma fluence of 8.78 ⋅ 10{sup 23} m{sup −2}. XPS analysis evidenced the formation of W{sub x}N{sub y} layers with nitrogen concentration in the range of 1–10% depending on the initial morphology and structure of the W samples. In all analyzed cases, nitrogen was bound and retained within the first 6 nm below the surface and no further diffusion of N into the bulk was observed.
Linearity of high-Tc dc superconducting quantum interference device operated in a flux-locked loop
Nichols, D.G.; Dantsker, E.; Kleiner, R.; Mueck, M.; Clarke, J.
1996-01-01
Measurements have been made of the linearity of a high transition temperature dc superconducting quantum interference device (SQUID) operated at 77 K with 130 kHz flux modulation in a flux-locked loop. The degree of nonlinearity was determined from harmonic generation. A sinusoidal magnetic flux with harmonic content less than -130 dB was applied to the SQUID, which was cooled in a magnetic field below 10 -7 T, and the harmonics at the output of the flux-locked loop were measured with a spectrum analyzer. For input signals at frequencies up to 248 Hz and amplitudes up to 20Φ 0 rms (Φ 0 is the flux quantum), the second, third, and fourth harmonics were each at least 115 dB below the fundamental. At higher frequencies the harmonic content began to increase because of the reduction in the open-loop gain of the flux-locked loop. The magnitude of the harmonics was not measurably changed when the SQUID was cooled in a field of 100 μT. The amplitudes of the even harmonics depended critically on the amplitude of the 130 kHz flux modulation, and became zero when its peak-to-peak value was precisely Φ 0 /2. copyright 1996 American Institute of Physics
Górecki, K; Zarȩbski, J
2014-01-01
The paper is devoted to modelling thermal properties of semiconductor devices at the steady state. The dc thermal model of a semiconductor device taking into account the multipath heat flow is proposed. Some results of calculations and measurements of thermal resistance of a power MOSFET operating at different cooling conditions are presented. The obtained results of calculations fit the results of measurements, which proves the correctness of the proposed model.
X. Jiang
2017-08-01
Full Text Available Laser induced breakdown spectroscopy (LIBS is a strong candidate for detecting and monitoring the H/D/T content on the surface of plasma facing components (PFCs due to its capability of fast direct in situ measurement in extreme environment (e.g., vacuum, magnetic field, long distance, complex geometry. To study the feasibilities and encounter the challenges of LIBS on plasma devices, a LIBS system has been set up on the linear plasma device PSI-2. A number of key parameters including laser energy, the influence of magnetic field and the persistence of laser induced plasma are studied. Real-time measurements of deuterium outgassing on tungsten samples exposed to deuterium plasma of 1025 D/m2 are performed in the first 40–130 min after plasma exposure. The experimental results are compared to the calculations in the literature.
Sung, Changhyuck; Lim, Seokjae; Kim, Hyungjun; Kim, Taesu; Moon, Kibong; Song, Jeonghwan; Kim, Jae-Joon; Hwang, Hyunsang
2018-03-01
To improve the classification accuracy of an image data set (CIFAR-10) by using analog input voltage, synapse devices with excellent conductance linearity (CL) and multi-level cell (MLC) characteristics are required. We analyze the CL and MLC characteristics of TaOx-based filamentary resistive random access memory (RRAM) to implement the synapse device in neural network hardware. Our findings show that the number of oxygen vacancies in the filament constriction region of the RRAM directly controls the CL and MLC characteristics. By adopting a Ta electrode (instead of Ti) and the hot-forming step, we could form a dense conductive filament. As a result, a wide range of conductance levels with CL is achieved and significantly improved image classification accuracy is confirmed.
Rancilio, Nicholas J; Dahl, Shaun; Athanasiadi, Ilektra; Perez-Torres, Carlos J
2017-12-01
The goal of this study was to design a positioning device that would allow for selective irradiation of the mouse brain with a clinical linear accelerator. We designed and fabricated an immobilization fixture that incorporates three functions: head stabilizer (through ear bars and tooth bar), gaseous anesthesia delivery and scavenging, and tissue mimic/bolus. Cohorts of five mice were irradiated such that each mouse in the cohort received a unique dose between 1000 and 3000 cGy. DNA damage immunohistochemistry was used to validate an increase in biological effect as a function of radiation dose. Mice were then followed with hematoxylin and eosin (H&E) and anatomical magnetic resonance imaging (MRI). There was evidence of DNA damage throughout the brain proportional to radiation dose. Radiation-induced damage at the prescribed doses, as depicted by H&E, appeared to be constrained to the white matter consistent with radiological observation in human patients. The severity of the damage correlated with the radiation dose as expected. We have designed and manufactured a device that allows us to selectively irradiate the mouse brain with a clinical linear accelerator. However, some off-target effects are possible with large prescription doses.
Preliminary design of experiment ALVAND 1 and low beta plasma source
Anvari, A.; Azodi, H.; Naraghi, M.; Taherzadeh, M.; Torabi-Fard, A.
1975-12-01
The ultimate goal of a two years program, namely ''ALVAND PROJECT'' and problems concerned with the achievement of controlled thermonuclear reactions in Iran is covered. The report consists of six sections. The introduction deals with the advantages of a linear theta pinch and its comparison with toroidal and mirror devices. Attention has been paid to two important properties of the ALVAND 1 device, namely, its property of carrying out important missions in support of high beta controlled thermonuclear research and also its acting as a source for developing different diagnostic apparatus and excercising different measurement techniques. Expected plasma parameters for ALVAND 1 are given in the third section. In the fourth section the low beta plasma source and the important diagnostic techniques that may be developed are discussed. References are given in the fifth section. The calculation of the minimum required radius of a toroidal theta pinch reactor has been given in an appendix, which covers at the same time 2 schematic figures. Finally a program schedule is presented in section six
Morgan, T. W.; Rindt, P.; van Eden, G. G.; Kvon, V.; Jaworksi, M. A.; Lopes Cardozo, N. J.
2018-01-01
For DEMO and beyond, liquid metal plasma-facing components are considered due to their resilience to erosion through flowed replacement, potential for cooling beyond conduction and inherent immunity to many of the issues of neutron loading compared to solid materials. The development curve of liquid metals is behind that of e.g. tungsten however, and tokamak-based research is currently somewhat limited in scope. Therefore, investigation into linear plasma devices can provide faster progress under controlled and well-diagnosed conditions in assessing many of the issues surrounding the use of liquid metals. The linear plasma devices Magnum-PSI and Pilot-PSI are capable of producing DEMO-relevant plasma fluxes, which well replicate expected divertor conditions, and the exploration of physics issues for tin (Sn) and lithium (Li) such as vapour shielding, erosion under high particle flux loading and overall power handling are reviewed here. A deeper understanding of erosion and deposition through this work indicates that stannane formation may play an important role in enhancing Sn erosion, while on the other hand the strong hydrogen isotope affinity reduces the evaporation rate and sputtering yields for Li. In combination with the strong redeposition rates, which have been observed under this type of high-density plasma, this implies that an increase in the operational temperature range, implying a power handling range of 20-25 MW m-2 for Sn and up to 12.5 MW m-2 for Li could be achieved. Vapour shielding may be expected to act as a self-protection mechanism in reducing the heat load to the substrate for off-normal events in the case of Sn, but may potentially be a continual mode of operation for Li.
Carr, Joseph
1996-01-01
The linear IC market is large and growing, as is the demand for well trained technicians and engineers who understand how these devices work and how to apply them. Linear Integrated Circuits provides in-depth coverage of the devices and their operation, but not at the expense of practical applications in which linear devices figure prominently. This book is written for a wide readership from FE and first degree students, to hobbyists and professionals.Chapter 1 offers a general introduction that will provide students with the foundations of linear IC technology. From chapter 2 onwa
Kobulnicky, K; Pawlak, D; Purwar, A
2015-01-01
Purpose: To examine the beam performance of a Varian TrueBeam linear accelerator under external device-based gated delivery conditions. Methods: Six gating cycles were used to evaluate the gating performance of a standard production TrueBeam system that was not specially tuned in any way. The system was equipped with a factory installed external gating interface (EXGI). An in-house EXGI tester box was used to simulate the input gating signals. The gating cycles were selected based on long beam-on and short beam-off times, short beam-on and long beam-off times, or equal beam on and off times to check linac performance. The beam latencies were measured as the time difference between the logic high gating signal and the first or last target pulses with an oscilloscope. Tissue-Phantom Ratio, beam flatness, and dose distributions from 5 different plans were measured using the 6 different gating durations and the un-gated irradiation. A PTW 729 2-D array was used to compare 5 plans versus the un-gated delivery with a 1%/1mm gamma index passing criteria. Results: The beam latencies of the linac were based off of 20 samples for beam-on and beam-off, for each gating cycle. The average beam-on delays were measured to be between 57 and 66msec, with a maximum of 88 msec. The beam off latencies averaged between 19 and 26msec, with a maximum of 48 msec. TPR20,10 measurements showed beam energy stability within 0.5% of the un-gated delivery. Beam flatness was better than 2.5% for all gated cycles. All but two deliveries, the open field with 4 seconds on, 1 second off, and a five field IMRT plan with 0.5 seconds on, 2.5 seconds off, had >90% passing rate. Conclusion: TrueBeam demonstrates excellent beam stability with minimal beam latencies under external device-based gated operations. Dosimetric measurements show minimal variation in beam energy, flatness, and plan delivery. Authors are employees of Varian Medical Systems, Inc
Kobulnicky, K; Pawlak, D; Purwar, A [Varian Medical Systems, Inc., Palo Alto, CA (United States)
2015-06-15
Purpose: To examine the beam performance of a Varian TrueBeam linear accelerator under external device-based gated delivery conditions. Methods: Six gating cycles were used to evaluate the gating performance of a standard production TrueBeam system that was not specially tuned in any way. The system was equipped with a factory installed external gating interface (EXGI). An in-house EXGI tester box was used to simulate the input gating signals. The gating cycles were selected based on long beam-on and short beam-off times, short beam-on and long beam-off times, or equal beam on and off times to check linac performance. The beam latencies were measured as the time difference between the logic high gating signal and the first or last target pulses with an oscilloscope. Tissue-Phantom Ratio, beam flatness, and dose distributions from 5 different plans were measured using the 6 different gating durations and the un-gated irradiation. A PTW 729 2-D array was used to compare 5 plans versus the un-gated delivery with a 1%/1mm gamma index passing criteria. Results: The beam latencies of the linac were based off of 20 samples for beam-on and beam-off, for each gating cycle. The average beam-on delays were measured to be between 57 and 66msec, with a maximum of 88 msec. The beam off latencies averaged between 19 and 26msec, with a maximum of 48 msec. TPR20,10 measurements showed beam energy stability within 0.5% of the un-gated delivery. Beam flatness was better than 2.5% for all gated cycles. All but two deliveries, the open field with 4 seconds on, 1 second off, and a five field IMRT plan with 0.5 seconds on, 2.5 seconds off, had >90% passing rate. Conclusion: TrueBeam demonstrates excellent beam stability with minimal beam latencies under external device-based gated operations. Dosimetric measurements show minimal variation in beam energy, flatness, and plan delivery. Authors are employees of Varian Medical Systems, Inc.
Nguyen, N; Knutson, N; Schmidt, M; Price, M
2016-01-01
Purpose: To verify a method used to automatically acquire jaw, MLC, collimator and couch star shots for a Varian TrueBeam linear accelerator utilizing Developer Mode and an Electronic Portal Imaging Device (EPID). Methods: An XML script was written to automate motion of the jaws, MLC, collimator and couch in TrueBeam Developer Mode (TBDM) to acquire star shot measurements. The XML script also dictates MV imaging parameters to facilitate automatic acquisition and recording of integrated EPID images. Since couch star shot measurements cannot be acquired using a combination of EPID and jaw/MLC collimation alone due to a fixed imager geometry, a method utilizing a 5mm wide steel ruler placed on the table and centered within a 15×15cm2 open field to produce a surrogate of the narrow field aperture was investigated. Four individual star shot measurements (X jaw, Y jaw, MLC and couch) were obtained using our proposed as well as traditional film-based method. Integrated EPID images and scanned measurement films were analyzed and compared. Results: Star shot (X jaw, Y jaw, MLC and couch) measurements were obtained in a single 5 minute delivery using the TBDM XML script method compared to 60 minutes for equivalent traditional film measurements. Analysis of the images and films demonstrated comparable isocentricity results, agreeing within 0.3mm of each other. Conclusion: The presented automatic approach of acquiring star shot measurements using TBDM and EPID has proven to be more efficient than the traditional film approach with equivalent results.
Lu, LingFeng
2016-01-01
Ion Cyclotron Resonant Heating (ICRH) by waves in 30-80 MHz range is currently used in magnetic fusion plasmas. Excited by phased arrays of current straps at the plasma periphery, these waves exist under two polarizations. The Fast Wave tunnels through the tenuous plasma edge and propagates to its center where it is absorbed. The parasitically emitted Slow Wave only exists close to the launchers. How much power can be coupled to the center with 1 A current on the straps? How do the emitted radiofrequency (RF) near and far fields interact parasitically with the edge plasma via RF sheath rectification at plasma-wall interfaces? To address these two issues simultaneously, in realistic geometry over the size of ICRH antennas, this thesis upgraded and tested the Self-consistent Sheaths and Waves for ICH (SSWICH) code. SSWICH couples self-consistently RF wave propagation and Direct Current (DC) plasma biasing via non-linear RF and DC sheath boundary conditions (SBCs) at plasma/wall interfaces. Its upgrade is full wave and was implemented in two dimensions (toroidal/radial). New SBCs coupling the two polarizations were derived and implemented along shaped walls tilted with respect to the confinement magnetic field. Using this new tool in the absence of SBCs, we studied the impact of a density decaying continuously inside the antenna box and across the Lower Hybrid (LH) resonance. Up to the memory limits of our workstation, the RF fields below the LH resonance changed with the grid size. However the coupled power spectrum hardly evolved and was only weakly affected by the density inside the box. In presence of SBCs, SSWICH-FW simulations have identified the role of the fast wave on RF sheath excitation and reproduced some key experimental observations. SSWICH-FW was finally adapted to conduct the first electromagnetic and RF-sheath 2D simulations of the cylindrical magnetized plasma device ALINE. (author) [fr
Construction of a high beta plasma source
Naraghi, M.; Torabi-Fard, A.
1976-02-01
A high beta plasma source has been designed and constructed. This source will serve as a means of developing and exercising different diagnostic techniques as required for ALVAND I, linear theta pinch experiment. Also, it will serve to acquaint the technicians with some of the techniques and safety rules of high voltage and capacitor discharge experiments. The operating parameters of the theta pinch and Z-pinch preionization is presented and the program of diagnostic measurements on the high beta plasma source is discussed
LASL: controlled thermonuclear research program. Progress report, January--December 1977
Thomas, K.S.; Sawyer, G.A.
1979-02-01
Information is included for each of the following sections: (1) reversed-field pinch program, (2) Scyllac feedback stabilization experiments, (3) Scylla IV-P linear theta pinch experiments, (4) staged theta pinch, (5) field-reversal experiment, (6) implosion heating experiment, (7) fast liner experiment, (8) gun injection experiment, (9) experimental plasma physics, (10) high-density z-pinch, (11) plasma diagnostics, (12) theory, (13) computers, (14) magnetic energy transfer and storage, (15) systems studies, (16) engineering, and (17) tritium systems test assembly
Review of the Los Alamos FRX-C experiment
Siemon, R.E.; Armstrong, W.T.; Barnes, D.C.
1985-01-01
The FRX-C device is a large field-reversed theta pinch experiment, with linear dimensions twice those of its FRX-A and FRX-B predecessors. It is used to form field-reversed configurations (FRCs), which are high-beta, highly prolate compact toroids. FRX-C has demonstrated an R 2 scaling for particle confinement in FRCs, indicating particles are lost by diffusive processes. Particle losses were also observed to dominate the energy balance. FRC lifetimes exceeding 300 μs were observed when weak quadrupole fields were applied to stabilize the n = 2 rotational mode. Detailed studies of the FRC equilibrium were performed using multi-chord and holographic interferometry. Measurements of electron temperature by Thomson scattering showed a flat profile and substantial losses through the electron channel. The loss rate of the internal poloidal flux of the FRC was observed to be anomalous and to scale less strongly with temperature than predicted from classical resistivity
Formation of compact toroidal configurations for magnetic confinement of high temperature plasmas
Fuentes, N.O.; Rodrigo, A.B.
1986-01-01
The formation stage of inverted magnetic field toroidal configurations (FRC) for hot plasmas confinement using a low energy linear theta pinch is studied. The diagnostic techniques used are based on optical spectroscopy, ultrarapid photography, magnetic probes and excluded flux compensated bonds. The generalities of the present research program, the used diagnostic techniques and the results obtained are discussed. (Author)
Wikner, Johannes; Hanken, Henning; Eulenburg, Christine; Heiland, Max; Groebe, Alexander; Assaf, Alexandre Thomas; Riecke, Bjoern; Friedrich, Reinhard E.
2016-01-01
Objective. To discriminate clinically relevant aberrance, the accuracy of linear measurements in three-dimensional (3D) reconstructed datasets was investigated. Materials and methods. Three partly edentulous human skulls were examined. Landmarks were defined prior to acquisition. Two CBCT-scanners
Christenson, M.; Stemmley, S.; Jung, S.; Mettler, J.; Sang, X.; Martin, D.; Kalathiparambil, K.; Ruzic, D. N.
2017-08-01
The ThermoElectric-driven Liquid-metal plasma-facing Structures (TELS) experiment at the University of Illinois is a gas-puff driven, theta-pinch plasma source that is used as a test stand for off-normal plasma events incident on materials in the edge and divertor regions of a tokamak. The ion temperatures and resulting energy distributions are crucial for understanding how well a TELS pulse can simulate an extreme event in a larger, magnetic confinement device. A retarding field energy analyzer (RFEA) has been constructed for use with such a transient plasma due to its inexpensive and robust nature. The innovation surrounding the use of a control analyzer in conjunction with an actively sampling analyzer is presented and the conditions of RFEA operation are discussed, with results presented demonstrating successful performance under extreme conditions. Such extreme conditions are defined by heat fluxes on the order of 0.8 GW m-2 and on time scales of nearly 200 μs. Measurements from the RFEA indicate two primary features for a typical TELS discharge, following closely with the pre-ionizing coaxial gun discharge characteristics. For the case using the pre-ionization pulse (PiP) and the theta pinch, the measured ion signal showed an ion temperature of 23.3 ± 6.6 eV for the first peak and 17.6 ± 1.9 eV for the second peak. For the case using only the PiP, the measured signal showed an ion temperature of 7.9 ± 1.1 eV for the first peak and 6.6 ± 0.8 eV for the second peak. These differences illustrate the effectiveness of the theta pinch for imparting energy on the ions. This information also highlights the importance of TELS as being one of the few linear pulsed plasma sources whereby moderately energetic ions will strike targets without the need for sample biasing.
Surface Plasma Arc by Radio-Frequency Control Study (SPARCS)
Ruzic, David N.
2013-01-01
This paper is to summarize the work carried out between April 2012 and April 2013 for development of an experimental device to simulate interactions of o-normal detrimental events in a tokamak and ICRF antenna. The work was mainly focused on development of a pulsed plasma source using theta pinch and coaxial plasma gun. This device, once completed, will have a possible application as a test stand for high voltage breakdown of an ICRF antenna in extreme events in a tokamak such as edge-localized modes or disruption. Currently, DEVeX does not produce plasma with high temperature enough to requirement for an ELM simulator. However, theta pinch is a good way to produce high temperature ions. The unique characteristic of plasma heating by a theta pinch is advantageous for an ELM simulator due to its effective ion heating. The objective of the proposed work, therefore, is to build a test facility using the existing theta pinch facility in addition to a coaxial plasma gun. It is expected to produce a similar pulsed-plasma heat load to the extreme events in tokamaks and to be applied for studying interactions of hot plasma and ICRF antennas
Development of a high energy pulsed plasma simulator for the study of liquid lithium trenches
Jung, S.; Christenson, M.; Curreli, D.; Bryniarski, C.; Andruczyk, D.; Ruzic, D.N.
2014-01-01
Highlights: • A pulse device for a liquid lithium trench study is developed. • It consists of a coaxial plasma gun, a theta pinch, and guiding magnets. • A large energy enhancement is observed with the use of the plasma gun. • A further increase in energy and velocity is observed with the theta pinch. - Abstract: To simulate detrimental events in a tokamak and provide a test-stand for a liquid-lithium infused trench (LiMIT) device [1], a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed. The plasma is characterized using a triple Langmuir probe, optical methods, and a calorimeter. Clear advantages have been observed with the application of a coaxial plasma accelerator as a pre-ionization source. The experimental results of the plasma gun in conjunction with the existing theta pinch show a significant improvement from the previous energy deposition by a factor of 14 or higher, resulting in a maximum energy and heat flux of 0.065 ± 0.002 MJ/m 2 and 0.43 ± 0.01 GW/m 2 . A few ways to further increase the plasma heat flux for LiMIT experiments are discussed
Development of a high energy pulsed plasma simulator for the study of liquid lithium trenches
Jung, S., E-mail: jung73@illinois.edu [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 (United States); Christenson, M.; Curreli, D. [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 (United States); Bryniarski, C. [Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 (United States); Andruczyk, D.; Ruzic, D.N. [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 (United States)
2014-12-15
Highlights: • A pulse device for a liquid lithium trench study is developed. • It consists of a coaxial plasma gun, a theta pinch, and guiding magnets. • A large energy enhancement is observed with the use of the plasma gun. • A further increase in energy and velocity is observed with the theta pinch. - Abstract: To simulate detrimental events in a tokamak and provide a test-stand for a liquid-lithium infused trench (LiMIT) device [1], a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed. The plasma is characterized using a triple Langmuir probe, optical methods, and a calorimeter. Clear advantages have been observed with the application of a coaxial plasma accelerator as a pre-ionization source. The experimental results of the plasma gun in conjunction with the existing theta pinch show a significant improvement from the previous energy deposition by a factor of 14 or higher, resulting in a maximum energy and heat flux of 0.065 ± 0.002 MJ/m{sup 2} and 0.43 ± 0.01 GW/m{sup 2}. A few ways to further increase the plasma heat flux for LiMIT experiments are discussed.
Shilov, Georgi E
1977-01-01
Covers determinants, linear spaces, systems of linear equations, linear functions of a vector argument, coordinate transformations, the canonical form of the matrix of a linear operator, bilinear and quadratic forms, Euclidean spaces, unitary spaces, quadratic forms in Euclidean and unitary spaces, finite-dimensional space. Problems with hints and answers.
Castejon M, F.
1989-01-01
The study of the Linear Theory microwave propagation and absorption in the the frequency range of electron cyclotron resonance, in a magnetized plasma, is developed. This study is particularized to the flexible heliac TJ-II, whose main characteristics are dsetailed in a memory chapter, as an interesting case example for its peculiar magnetic configuration. As a preliminary phase, a cold plasma model is useds to analyze the resonance accessibility and the approximated density limits which will be obtainable in each electron cyclotron resonance harmonic. This analysis was used to find the suitable positions for the microwave injection in TJ-II. An analytical weakly relativistic model for the dielectric tensor is developed, valid for oblique propagation, that takes account of the effect of superthermal electrons. Second order Larmor radius effects are included, so that the Quasi-Electrostatic branch of X mode can be studied. A numerical study is then presented on the absorption properties of TJ-II. Since the TJ-II geometry is complex and its magnetic field distribution is very different from that of a tokamak, ray tracing calculations are necessary to consider refraction effects. The ray tracing codse RAYS, developed in the Oak Ridge National Laboratory (U.S.A.), was take and adapted to the helical magnetic configuration of the TJ-II. The absorption model described above was then included in RAYS. For completeness, an introduction to the Quasi Linear Theory, natural prolongation of this work, is included at the end of the memory, ands the effects of taking into account the quasi linear evolution of the distribution function are described. (Author)
Mamyrin, B.A.; Shmikk, D.V.
1979-01-01
A description and operating principle of a linear mass reflectron with V-form trajectory of ion motion -a new non-magnetic time-of-flight mass spectrometer with high resolution are presented. The ion-optical system of the device consists of an ion source with ionization by electron shock, of accelerating gaps, reflector gaps, a drift space and ion detector. Ions move in the linear mass refraction along the trajectories parallel to the axis of the analyzer chamber. The results of investigations into the experimental device are given. With an ion drift length of 0.6 m the device resolution is 1200 with respect to the peak width at half-height. Small-sized mass spectrometric transducers with high resolution and sensitivity may be designed on the base of the linear mass reflectron principle
Kaminski, Adam
2017-08-22
A method and apparatus to generate harmonically related laser wavelengths includes a pair of lenses at opposing faces of a non-linear optical material. The lenses are configured to promote incoming and outgoing beams to be normal to each outer lens surface over a range of acceptance angles of the incoming laser beam. This reduces reflection loss for higher efficiency operation. Additionally, the lenses allow a wider range of wavelengths for lasers for more universal application. Examples of the lenses include plano-cylindrical and plano-spherical form factors.
Maxim Goryachev
2018-04-01
Full Text Available A quartz Bulk Acoustic Wave resonator is designed to coherently trap phonons in such a way that they are well confined and immune to suspension losses so they exhibit extremely high acoustic Q-factors at low temperature, with Q × f products of order 10 18 Hz. In this work we couple such a resonator to a Superconducting Quantum Interference Device (SQUID amplifier and investigate effects in the strong signal regime. Both parallel and series connection topologies of the system are investigated. The study reveals significant non-Duffing response that is associated with the nonlinear characteristics of Josephson junctions. The nonlinearity provides quasi-periodic structure of the spectrum in both incident power and frequency. The result gives an insight into the open loop behaviour of a future Cryogenic Quartz Oscillator in the strong signal regime.
Wang, Wenjun; Li, Peng; Jin, Feng
2016-09-01
A novel two-dimensional linear elastic theory of magneto-electro-elastic (MEE) plates, considering both surface and nonlocal effects, is established for the first time based on Hamilton’s principle and the Lee plate theory. The equations derived are more general, suitable for static and dynamic analyses, and can also be reduced to the piezoelectric, piezomagnetic, and elastic cases. As a specific application example, the influences of the surface and nonlocal effects, poling directions, piezoelectric phase materials, volume fraction, damping, and applied magnetic field (i.e., constant applied magnetic field and time-harmonic applied magnetic field) on the magnetoelectric (ME) coupling effects are first investigated based on the established two-dimensional plate theory. The results show that the ME coupling coefficient has an obvious size-dependent characteristic owing to the surface effects, and the surface effects increase the ME coupling effects significantly when the plate thickness decreases to its critical thickness. Below this critical thickness, the size-dependent effect is obvious and must be considered. In addition, the output power density of a magnetic energy nanoharvester is also evaluated using the two-dimensional plate theory obtained, with the results showing that a relatively larger output power density can be achieved at the nanoscale. This study provides a mathematical tool which can be used to analyze the mechanical properties of nanostructures theoretically and numerically, as well as evaluating the size effect qualitatively and quantitatively.
Brovchenko, V G [Ordena Lenina Institut Atomnoj Ehnergii Imeni I.V. Kurchatova AN, SSSR (Russian Federation)
1962-04-15
The linearity of information storage in capacitor storage circuits is discussed. The paper describes two storage circuits whose operation is linear over a wide range of output-signal amplitudes. In one of the circuits the error signal is measured by a differential amplifier and, thanks to the high amplification factor of the amplifier, good linearity is obtained. The second circuit was designed for work in the nanosecond pulse-width range. Input pulses of standard width cut off a pentode, in the anode of which there is a memory capacitor. Since the capacitor is charged from the anode supply through a current generator, the charging current remains almost constant during measurement of the capacitor voltage. The pentode has a large internal resistance so that after the end of the input pulse the magnitude of the current through the pentode is almost equal to its initial value, and the charge stored by the capacitor is remembered. The width of the information memory is limited by the output resistance of the current generator and the internal resistance (R{sub i}) of the pentode. To increase the memory width, a diode may be inserted before the capacitor. (author) [French] L'auteur examine les questions que pose la linearite du stockage des informations par des memoires a condensateurs. Il decrit deux circuits de memoires dont le fonctionntement est lineaire pour une vaste gamme d'amplitude des signaux de sortie. Dans l'un des circuits, le signal d'erreur est mesure par un amplificateur differentiel. Le coefficient d'amplification eleve permet d'obtenir une grande linearite dans le fonctionnement du dispositif. Le deuxieme circuit est construit pour des impulsions dont la duree est de l'ordre d'une nanoseconde. Les impulsions incidentes de duree normalisee bloquent la penthode, a l'anode de laquelle est dispose le condensateur de la memoire. Comme le condensateur est charge par' une alimentation anodique au moyen d'une generatrice electrique, le courant de chargement
Suwono.
1978-01-01
A linear gate providing a variable gate duration from 0,40μsec to 4μsec was developed. The electronic circuity consists of a linear circuit and an enable circuit. The input signal can be either unipolar or bipolar. If the input signal is bipolar, the negative portion will be filtered. The operation of the linear gate is controlled by the application of a positive enable pulse. (author)
Vretenar, M
2014-01-01
The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics
Linearization Method and Linear Complexity
Tanaka, Hidema
We focus on the relationship between the linearization method and linear complexity and show that the linearization method is another effective technique for calculating linear complexity. We analyze its effectiveness by comparing with the logic circuit method. We compare the relevant conditions and necessary computational cost with those of the Berlekamp-Massey algorithm and the Games-Chan algorithm. The significant property of a linearization method is that it needs no output sequence from a pseudo-random number generator (PRNG) because it calculates linear complexity using the algebraic expression of its algorithm. When a PRNG has n [bit] stages (registers or internal states), the necessary computational cost is smaller than O(2n). On the other hand, the Berlekamp-Massey algorithm needs O(N2) where N(≅2n) denotes period. Since existing methods calculate using the output sequence, an initial value of PRNG influences a resultant value of linear complexity. Therefore, a linear complexity is generally given as an estimate value. On the other hand, a linearization method calculates from an algorithm of PRNG, it can determine the lower bound of linear complexity.
Said-Houari, Belkacem
2017-01-01
This self-contained, clearly written textbook on linear algebra is easily accessible for students. It begins with the simple linear equation and generalizes several notions from this equation for the system of linear equations and introduces the main ideas using matrices. It then offers a detailed chapter on determinants and introduces the main ideas with detailed proofs. The third chapter introduces the Euclidean spaces using very simple geometric ideas and discusses various major inequalities and identities. These ideas offer a solid basis for understanding general Hilbert spaces in functional analysis. The following two chapters address general vector spaces, including some rigorous proofs to all the main results, and linear transformation: areas that are ignored or are poorly explained in many textbooks. Chapter 6 introduces the idea of matrices using linear transformation, which is easier to understand than the usual theory of matrices approach. The final two chapters are more advanced, introducing t...
Stoll, R R
1968-01-01
Linear Algebra is intended to be used as a text for a one-semester course in linear algebra at the undergraduate level. The treatment of the subject will be both useful to students of mathematics and those interested primarily in applications of the theory. The major prerequisite for mastering the material is the readiness of the student to reason abstractly. Specifically, this calls for an understanding of the fact that axioms are assumptions and that theorems are logical consequences of one or more axioms. Familiarity with calculus and linear differential equations is required for understand
Tronc, D.
1994-01-01
The invention concerns a proton therapy device using a proton linear accelerator which produces a proton beam with high energies and intensities. The invention lies in actual fact that the proton beam which is produced by the linear accelerator is deflected from 270 deg in its plan by a deflecting magnetic device towards a patient support including a bed the longitudinal axis of which is parallel to the proton beam leaving the linear accelerator. The patient support and the deflecting device turn together around the proton beam axis while the bed stays in an horizontal position. The invention applies to radiotherapy. 6 refs., 5 figs
Solow, Daniel
2014-01-01
This text covers the basic theory and computation for a first course in linear programming, including substantial material on mathematical proof techniques and sophisticated computation methods. Includes Appendix on using Excel. 1984 edition.
Liesen, Jörg
2015-01-01
This self-contained textbook takes a matrix-oriented approach to linear algebra and presents a complete theory, including all details and proofs, culminating in the Jordan canonical form and its proof. Throughout the development, the applicability of the results is highlighted. Additionally, the book presents special topics from applied linear algebra including matrix functions, the singular value decomposition, the Kronecker product and linear matrix equations. The matrix-oriented approach to linear algebra leads to a better intuition and a deeper understanding of the abstract concepts, and therefore simplifies their use in real world applications. Some of these applications are presented in detailed examples. In several ‘MATLAB-Minutes’ students can comprehend the concepts and results using computational experiments. Necessary basics for the use of MATLAB are presented in a short introduction. Students can also actively work with the material and practice their mathematical skills in more than 300 exerc...
Berberian, Sterling K
2014-01-01
Introductory treatment covers basic theory of vector spaces and linear maps - dimension, determinants, eigenvalues, and eigenvectors - plus more advanced topics such as the study of canonical forms for matrices. 1992 edition.
Searle, Shayle R
2012-01-01
This 1971 classic on linear models is once again available--as a Wiley Classics Library Edition. It features material that can be understood by any statistician who understands matrix algebra and basic statistical methods.
Christofilos, N.C.; Polk, I.J.
1959-02-17
Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.
Variable linear motion cycle monitoring device
Ezekoye, L.I.; Cavada, D.R.
1989-01-01
A pressurized water reactor nuclear power plant is described including feedwater flow control valve having a valve member which can be moved varying amounts in discrete movements in either direction between an open and a closed position to control feedwater flow; and apparatus for recording cycles of reciprocal movement of the valve member. The apparatus consists of: a travel translator member, means connecting the travel translator member to the valve member for reciprocal rectilinear movement in direction corresponding to, and for a distance proportional to, the movement of the valve member, a shaft member for rotation its longitudinal axis, means for limiting angular rotation of the shaft member in each direction; means for counting cycles of reciprocal rotation of the shaft member between rotating limits set by the limiting mean; a wheel mounted on the shaft member and in engagement with the travel translator member the wheel translating movement of the travel translator into rotation of the shaft member between the limits of rotation of the shaft member set by the limit means, and means permitting relative movement between the wheel and one of the member once the limits of rotation of the shaft member are reached and the travel translator member continues movement in the same direction
Olive, David J
2017-01-01
This text covers both multiple linear regression and some experimental design models. The text uses the response plot to visualize the model and to detect outliers, does not assume that the error distribution has a known parametric distribution, develops prediction intervals that work when the error distribution is unknown, suggests bootstrap hypothesis tests that may be useful for inference after variable selection, and develops prediction regions and large sample theory for the multivariate linear regression model that has m response variables. A relationship between multivariate prediction regions and confidence regions provides a simple way to bootstrap confidence regions. These confidence regions often provide a practical method for testing hypotheses. There is also a chapter on generalized linear models and generalized additive models. There are many R functions to produce response and residual plots, to simulate prediction intervals and hypothesis tests, to detect outliers, and to choose response trans...
Alcaraz, J.
2001-01-01
After several years of study e''+ e''- linear colliders in the TeV range have emerged as the major and optimal high-energy physics projects for the post-LHC era. These notes summarize the present status form the main accelerator and detector features to their physics potential. The LHC era. These notes summarize the present status, from the main accelerator and detector features to their physics potential. The LHC is expected to provide first discoveries in the new energy domain, whereas an e''+ e''- linear collider in the 500 GeV-1 TeV will be able to complement it to an unprecedented level of precision in any possible areas: Higgs, signals beyond the SM and electroweak measurements. It is evident that the Linear Collider program will constitute a major step in the understanding of the nature of the new physics beyond the Standard Model. (Author) 22 refs
Edwards, Harold M
1995-01-01
In his new undergraduate textbook, Harold M Edwards proposes a radically new and thoroughly algorithmic approach to linear algebra Originally inspired by the constructive philosophy of mathematics championed in the 19th century by Leopold Kronecker, the approach is well suited to students in the computer-dominated late 20th century Each proof is an algorithm described in English that can be translated into the computer language the class is using and put to work solving problems and generating new examples, making the study of linear algebra a truly interactive experience Designed for a one-semester course, this text adopts an algorithmic approach to linear algebra giving the student many examples to work through and copious exercises to test their skills and extend their knowledge of the subject Students at all levels will find much interactive instruction in this text while teachers will find stimulating examples and methods of approach to the subject
Banks, E.L. Jr.; Dowell, T.P.
1976-01-01
The description is given of a damper which includes a pair of telescopic components interconnected by relative linear movement one in relation to the other, by a screw and ball nut device, with a braking surface on one of the components, a brake engaging the braking surface, an inertia mass entrained by the other components, non-deformable and distinct brake actuating gear, independently mobile in relation to the other braking system and fixed and controlled by the inertia mass, positively to engage the braking surface. This damper is for retaining the parts of a nuclear power station so that can withstand earthquakes [fr
Tjutju, R.L.
1977-01-01
Pulse amplifier is standard significant part of spectrometer. Apart from other type of amplification, it's a combination of amplification and pulse shaping. Because of its special purpose the device should fulfill the following : High resolution is desired to gain a high yield comparable to its actual state of condition. High signal to noise is desired to nhν resolution. High linearity to facilitate calibration. A good overload recovery, in order to the device will capable of analizing a low energy radiation which appear joinly on the high energy fields. Other expections of the device are its economical and practical use its extentive application. For that reason it's built on a standard NIM principle. Taking also into account the above mentioned considerations. High quality component parts are used throughout, while its availability in the domestic market is secured. (author)
Karloff, Howard
1991-01-01
To this reviewer’s knowledge, this is the first book accessible to the upper division undergraduate or beginning graduate student that surveys linear programming from the Simplex Method…via the Ellipsoid algorithm to Karmarkar’s algorithm. Moreover, its point of view is algorithmic and thus it provides both a history and a case history of work in complexity theory. The presentation is admirable; Karloff's style is informal (even humorous at times) without sacrificing anything necessary for understanding. Diagrams (including horizontal brackets that group terms) aid in providing clarity. The end-of-chapter notes are helpful...Recommended highly for acquisition, since it is not only a textbook, but can also be used for independent reading and study. —Choice Reviews The reader will be well served by reading the monograph from cover to cover. The author succeeds in providing a concise, readable, understandable introduction to modern linear programming. —Mathematics of Computing This is a textbook intend...
Electronic devices and circuits
Pridham, Gordon John
1972-01-01
Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of
Reduction of Linear Programming to Linear Approximation
Vaserstein, Leonid N.
2006-01-01
It is well known that every Chebyshev linear approximation problem can be reduced to a linear program. In this paper we show that conversely every linear program can be reduced to a Chebyshev linear approximation problem.
Development of high energy pulsed plasma simulator for plasma-lithium trench experiment
Jung, Soonwook
To simulate detrimental events in a tokamak and provide a test-stand for a liquid lithium infused trench (LiMIT) device, a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed. An overall objective of the project is to develop a compact device that can produce 100 MW/m2 to 1 GW/m2 of plasma heat flux (a typical heat flux level in a major fusion device) in ~ 100 mus (≤ 0.1 MJ/m2) for a liquid lithium plasma facing component research. The existing theta pinch device, DEVeX, was built and operated for study on lithium vapor shielding effect. However, a typical plasma energy of 3 - 4 kJ/m2 is too low to study an interaction of plasma and plasma facing components in fusion devices. No or little preionized plasma, ringing of magnetic field, collisions of high energy particles with background gas have been reported as the main issues. Therefore, DEVeX is reconfigured to mitigate these issues. The new device is mainly composed of a plasma gun for a preionization source, a theta pinch for heating, and guiding magnets for a better plasma transportation. Each component will be driven by capacitor banks and controlled by high voltage / current switches. Several diagnostics including triple Langmuir probe, calorimeter, optical emission measurement, Rogowski coil, flux loop, and fast ionization gauge are used to characterize the new device. A coaxial plasma gun is manufactured and installed in the previous theta pinch chamber. The plasma gun is equipped with 500 uF capacitor and a gas puff valve. The increase of the plasma velocity with the plasma gun capacitor voltage is consistent with the theoretical predictions and the velocity is located between the snowplow model and the weak - coupling limit. Plasma energies measured with the calorimeter ranges from 0.02 - 0.065 MJ/m2 and increases with the voltage at the capacitor bank. A cross-check between the plasma energy measured with the calorimeter and the triple probe
Experiments with vacuum interrupters used for large dc-current interruption
Warren, R.W.
1977-10-01
Vacuum interrupters have been tested in circuits similar to those used in theta-pinch and Tokamak fusion devices. The effects on performance of auxiliary circuit components and axial magnetic fields have been determined, and limits to lifetime caused by mechanical and electrical wear have been measured. Results show that the upper reliable limit of interruption is independent of the auxiliary components but quite dependent on interrupter size and on the axial field
Tanwiwat Jaikuna
2017-02-01
Full Text Available Purpose: To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL model. Material and methods : The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose volume histograms. The physical dose from each voxel in treatment planning was extracted through Computational Environment for Radiotherapy Research (CERR, and the accuracy was verified by the differentiation between the dose volume histogram from CERR and the treatment planning system. An equivalent dose in 2 Gy fraction (EQD2 was calculated using biological effective dose (BED based on the LQL model. The software calculation and the manual calculation were compared for EQD2 verification with pair t-test statistical analysis using IBM SPSS Statistics version 22 (64-bit. Results: Two and three-dimensional biological dose distribution and biological dose volume histogram were displayed correctly by the Isobio software. Different physical doses were found between CERR and treatment planning system (TPS in Oncentra, with 3.33% in high-risk clinical target volume (HR-CTV determined by D90%, 0.56% in the bladder, 1.74% in the rectum when determined by D2cc, and less than 1% in Pinnacle. The difference in the EQD2 between the software calculation and the manual calculation was not significantly different with 0.00% at p-values 0.820, 0.095, and 0.593 for external beam radiation therapy (EBRT and 0.240, 0.320, and 0.849 for brachytherapy (BT in HR-CTV, bladder, and rectum, respectively. Conclusions : The Isobio software is a feasible tool to generate the biological dose distribution and biological dose volume histogram for treatment plan evaluation in both EBRT and BT.
Quasi-spherical compression of a spark-channel plasma
Panarella, E.
1980-01-01
An axial spark channel in deuterium has been used as a target for implosive shock waves created with a conventional cylindrical theta-pinch device. The compression of the channel by the implosive waves raised the plasma electron temperature to approximately 120 eV for approximately 6 kJ of condenser bank energy and 1 Torr initial gas pressure. In order to improve the efficiency of compression of the channel plasma and to reduce the end losses inherent in the cylindrical configuration, the theta-pinch geometry was then converted from cylindrical into spherical. Under identical conditions of gas pressure and condenser bank energy, the electron temperature now peaked at approximately 400 eV. When the bank energy was increased to approximately 10 kJ, neutron production was observed. The total neutron output per shot ranged from 10 5 to 10 6 and increased inversely with the pinch discharge volume
Control method for prosthetic devices
Bozeman, Richard J., Jr. (Inventor)
1995-01-01
A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.
An introduction to electrooptic devices
Kaminow, Ivan P
1974-01-01
An Introduction to Electrooptic Devices aims to present an introduction to the electrooptic effect and to summarize work on devices employing the electrooptic effect. The book provides the necessary background in classical crystal optics. The text then discusses topics including crystal symmetry, the tensor description of linear dielectric properties, propagation in anisotropic media, and passive crystal optic devices. The book also describes the phenomenological description of tensor nonlinear dielectric properties of crystals, with emphasis on the electrooptic effect; device design and appli
Romadanov, I.V.; Ryzhkov, S.V., E-mail: ryzhkov@power.bmstu.ru
2014-12-15
Highlights: • Compact torus formation method with high level of magnetic flux is proposed. • A compact torus is produced in a theta-pinch-coil with pulse mode of operation. • Key feature is a pulse of current in an axial direction. • We report a level of linked magnetic flux is higher than theta-pinch results. - Abstract: The present work reports on compact toroid hydrogen plasma creation by means of a specially designed discharge system and results of magnetic fields introduction. Experiments in the compact toroid challenge (CTC) device at P.N. Lebedev Physical Institute (FIAN) have been conducted since 2005. The CTC device differs from the conventional theta-pinch formation in the use of an axial current for enhanced efficiency. We have used a novel technique to maximize the flux linked to the plasma. The purpose of this method is to increase the energy input into the plasma and the level of trapped magnetic flux using an additional toroidal magnetic field. A study of compact torus formation with axial and toroidal currents was done and a new method is proposed and implemented.
Acoustic emission linear pulse holography
Collins, H.D.; Busse, L.J.; Lemon, D.K.
1983-10-25
This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.
Linear Algebra and Smarandache Linear Algebra
Vasantha, Kandasamy
2003-01-01
The present book, on Smarandache linear algebra, not only studies the Smarandache analogues of linear algebra and its applications, it also aims to bridge the need for new research topics pertaining to linear algebra, purely in the algebraic sense. We have introduced Smarandache semilinear algebra, Smarandache bilinear algebra and Smarandache anti-linear algebra and their fuzzy equivalents. Moreover, in this book, we have brought out the study of linear algebra and vector spaces over finite p...
Remote detection of electronic devices
Judd, Stephen L [Los Alamos, NM; Fortgang, Clifford M [Los Alamos, NM; Guenther, David C [Los Alamos, NM
2012-09-25
An apparatus and method for detecting solid-state electronic devices are described. Non-linear junction detection techniques are combined with spread-spectrum encoding and cross correlation to increase the range and sensitivity of the non-linear junction detection and to permit the determination of the distances of the detected electronics. Nonlinear elements are detected by transmitting a signal at a chosen frequency and detecting higher harmonic signals that are returned from responding devices.
Dynamic linearization system for a radiation gauge
Panarello, J.A.
1977-01-01
The linearization system and process converts a high resolution non-linear analog input signal, representative of the thickness of an object, into a high resolution linear analog output signal suitable for use in driving a variety of output devices. The system requires only a small amount of memory for storing pre-calculated non-linear correction coefficients. The system channels the input signal to separate circuit paths so that it may be used directly to; locate an appropriate correction coefficient; develop a correction term after an appropriate correction coefficient is located; and develop a linearized signal having the same high resolution inherent in the input signal. The system processes the linearized signal to compensate for the possible errors introduced by radiation source noise. The processed linearized signal is the high resolution linear analog output signal which accurately represents the thickness of the object being gauged
Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R
2017-03-21
The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.
Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.
2015-06-02
The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.
Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.
2015-09-01
The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.
Advanced analysis technique for the evaluation of linear alternators and linear motors
Holliday, Jeffrey C.
1995-01-01
A method for the mathematical analysis of linear alternator and linear motor devices and designs is described, and an example of its use is included. The technique seeks to surpass other methods of analysis by including more rigorous treatment of phenomena normally omitted or coarsely approximated such as eddy braking, non-linear material properties, and power losses generated within structures surrounding the device. The technique is broadly applicable to linear alternators and linear motors involving iron yoke structures and moving permanent magnets. The technique involves the application of Amperian current equivalents to the modeling of the moving permanent magnet components within a finite element formulation. The resulting steady state and transient mode field solutions can simultaneously account for the moving and static field sources within and around the device.
Linearly constrained minimax optimization
Madsen, Kaj; Schjær-Jacobsen, Hans
1978-01-01
We present an algorithm for nonlinear minimax optimization subject to linear equality and inequality constraints which requires first order partial derivatives. The algorithm is based on successive linear approximations to the functions defining the problem. The resulting linear subproblems...
Control System for Prosthetic Devices
Bozeman, Richard J. (Inventor)
1996-01-01
A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that of movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the moveable body part through the full-shrg position of the moveable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the moveable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective moveable prosthesis device and its sub-prosthesis.
Foundations of linear and generalized linear models
Agresti, Alan
2015-01-01
A valuable overview of the most important ideas and results in statistical analysis Written by a highly-experienced author, Foundations of Linear and Generalized Linear Models is a clear and comprehensive guide to the key concepts and results of linear statistical models. The book presents a broad, in-depth overview of the most commonly used statistical models by discussing the theory underlying the models, R software applications, and examples with crafted models to elucidate key ideas and promote practical model building. The book begins by illustrating the fundamentals of linear models,
1980-02-01
The TPA (torus plasma for amature) is a small race-trac type device made by the technical service division to demonstrate basic properties of plasma such as electron temperature, conductivity, effect of helical field for toroidal drift, and shape of plasma in mirror and cusp magnetic field in linear section. The plasmas are produced by RF discharge (-500W) and/or DC discharge (-30 mA) within glass discharge tube. Where major radius is 50 cm, length of linear section is 50 cm, toroidal magnetic field is 200 gauss. The device has been designed to be compact with only 100 V power source (-3.2 KW for the case without helical field) and to be full automatic sequence of operation. (author)
Garcia-Crespo, Andres Jose
2013-12-10
A sealing device for sealing a gap between a dovetail of a bucket assembly and a rotor wheel is disclosed. The sealing device includes a cover plate configured to cover the gap and a retention member protruding from the cover plate and configured to engage the dovetail. The sealing device provides a seal against the gap when the bucket assemply is subjected to a centrifugal force.
Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)
2017-01-01
Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.
Qurnell, F.D.; Patterson, C.B.
1979-01-01
A gauge supporting device for measuring say a square tube comprises a pair of rods or guides in tension between a pair of end members, the end members being spaced apart by a compression member or members. The tensioned guides provide planes of reference for measuring devices moved therealong on a carriage. The device is especially useful for making on site dimensional measurements of components, such as irradiated and therefore radioactive components, that cannot readily be transported to an inspection laboratory. (UK)
Free piston variable-stroke linear-alternator generator
Haaland, Carsten M.
1998-01-01
A free-piston variable stroke linear-alternator AC power generator for a combustion engine. An alternator mechanism and oscillator system generates AC current. The oscillation system includes two oscillation devices each having a combustion cylinder and a flying turnbuckle. The flying turnbuckle moves in accordance with the oscillation device. The alternator system is a linear alternator coupled between the two oscillation devices by a slotted connecting rod.
Fowler, T.K.
1977-01-01
Three types of thermonuclear fusion devices currently under development are reviewed for an electric utilities management audience. Overall design features of laser fusion, tokamak, and magnetic mirror type reactors are described and illustrated. Thrusts and trends in current research on these devices that promise to improve performance are briefly reviewed. Twenty photographs and drawings are included
O'Donnell, T.J.
1959-03-10
A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.
A linear magnetic motor and generator
Studer, P. A.
1980-01-01
In linear magnetic motor and generator suitable for remote and hostile environments, magnetic forces drive reciprocating shaft along its axis. Actuator shaft is located in center of cylindrical body and may be supported by either contacting or noncontacting bearings. When device operates as bidirectional motor, drive coil selectively adds and subtracts magnetic flux to and from flux paths, producing forces that drive actuator along axis. When actuator is driven by external reciprocating engine, device becomes ac generator.
Gow, J.D.; Wilcox, J.M.
1961-12-26
A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)
Computational aspects of linear control
2002-01-01
Many devices (we say dynamical systems or simply systems) behave like black boxes: they receive an input, this input is transformed following some laws (usually a differential equation) and an output is observed. The problem is to regulate the input in order to control the output, that is for obtaining a desired output. Such a mechanism, where the input is modified according to the output measured, is called feedback. The study and design of such automatic processes is called control theory. As we will see, the term system embraces any device and control theory has a wide variety of applications in the real world. Control theory is an interdisci plinary domain at the junction of differential and difference equations, system theory and statistics. Moreover, the solution of a control problem involves many topics of numerical analysis and leads to many interesting computational problems: linear algebra (QR, SVD, projections, Schur complement, structured matrices, localization of eigenvalues, computation of the...
An adjustable linear Halbach array
Hilton, J.E., E-mail: James.Hilton@csiro.au [CSIRO Mathematics, Informatics and Statistics, Clayton South, VIC 3169 (Australia); McMurry, S.M. [School of Physics, Trinity College, Dublin (Ireland)
2012-07-15
The linear Halbach array is a well-known planar magnetic structure capable, in the idealized case, of generating a one-sided magnetic field. We show that such a field can be created from an array of uniformly magnetized rods, and rotating these rods in an alternating fashion can smoothly transfer the resultant magnetic field through the plane of the device. We examine an idealized model composed of infinite line dipoles and carry out computational simulations on a realizable device using a magnetic boundary element method. Such an arrangement can be used for an efficient latching device, or to produce a highly tunable field in the space above the device. - Highlights: Black-Right-Pointing-Pointer We model an adjustable 'one-sided' flux sheet made up of a series of dipolar magnetic field sources. Black-Right-Pointing-Pointer We show that magnetic field can be switched from one side of sheet to other by a swap rotation of each of magnetic sources. Black-Right-Pointing-Pointer Investigations show that such an arrangement is practical and can easily be fabricated. Black-Right-Pointing-Pointer The design has a wide range of potential applications.
An adjustable linear Halbach array
Hilton, J.E.; McMurry, S.M.
2012-01-01
The linear Halbach array is a well-known planar magnetic structure capable, in the idealized case, of generating a one-sided magnetic field. We show that such a field can be created from an array of uniformly magnetized rods, and rotating these rods in an alternating fashion can smoothly transfer the resultant magnetic field through the plane of the device. We examine an idealized model composed of infinite line dipoles and carry out computational simulations on a realizable device using a magnetic boundary element method. Such an arrangement can be used for an efficient latching device, or to produce a highly tunable field in the space above the device. - Highlights: ► We model an adjustable ‘one-sided’ flux sheet made up of a series of dipolar magnetic field sources. ► We show that magnetic field can be switched from one side of sheet to other by a swap rotation of each of magnetic sources. ► Investigations show that such an arrangement is practical and can easily be fabricated. ► The design has a wide range of potential applications.
Tuey, R. C.
1972-01-01
Computer solutions of linear programming problems are outlined. Information covers vector spaces, convex sets, and matrix algebra elements for solving simultaneous linear equations. Dual problems, reduced cost analysis, ranges, and error analysis are illustrated.
Peterson, David; Stofleth, Jerome H.; Saul, Venner W.
2017-07-11
Linear shaped charges are described herein. In a general embodiment, the linear shaped charge has an explosive with an elongated arrowhead-shaped profile. The linear shaped charge also has and an elongated v-shaped liner that is inset into a recess of the explosive. Another linear shaped charge includes an explosive that is shaped as a star-shaped prism. Liners are inset into crevices of the explosive, where the explosive acts as a tamper.
Classifying Linear Canonical Relations
Lorand, Jonathan
2015-01-01
In this Master's thesis, we consider the problem of classifying, up to conjugation by linear symplectomorphisms, linear canonical relations (lagrangian correspondences) from a finite-dimensional symplectic vector space to itself. We give an elementary introduction to the theory of linear canonical relations and present partial results toward the classification problem. This exposition should be accessible to undergraduate students with a basic familiarity with linear algebra.
Lawson, C. L.; Krogh, F. T.; Gold, S. S.; Kincaid, D. R.; Sullivan, J.; Williams, E.; Hanson, R. J.; Haskell, K.; Dongarra, J.; Moler, C. B.
1982-01-01
The Basic Linear Algebra Subprograms (BLAS) library is a collection of 38 FORTRAN-callable routines for performing basic operations of numerical linear algebra. BLAS library is portable and efficient source of basic operations for designers of programs involving linear algebriac computations. BLAS library is supplied in portable FORTRAN and Assembler code versions for IBM 370, UNIVAC 1100 and CDC 6000 series computers.
Coulson, R.A.
1980-01-01
A sealing device for minimising the leakage of toxic or radioactive contaminated environments through a biological shield along an opening through which a flexible component moves that penetrates the shield. The sealing device comprises an outer tubular member which extends over a length not less than the maximum longitudinal movement of the component along the opening. An inner sealing block is located intermediate the length of the component by connectors and is positioned in the bore of the outer tubular member to slide in the bore and effect a seal over the entire longitudinal movement of the component. The cross-section of the device may be circular and the block may be of polytetrafluoroethylene or of nylon impregnated with molybdenum or may be metallic. A number of the sealing devices may be combined into an assembly for a plurality of adjacent longitudinally movable components, each adapted to sustain a tensile load, providing the various drives of a master-slave manipulator. (author)
Uchino, Kenji
2009-01-01
Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat
Noise limitations in optical linear algebra processors.
Batsell, S G; Jong, T L; Walkup, J F; Krile, T F
1990-05-10
A general statistical noise model is presented for optical linear algebra processors. A statistical analysis which includes device noise, the multiplication process, and the addition operation is undertaken. We focus on those processes which are architecturally independent. Finally, experimental results which verify the analytical predictions are also presented.
Linear motor with contactless energy transfer
2014-01-01
An integrated electromagnetic energy conversions device is provided that includes a synchronous or brushless linear (SoBL) motor, and a transformer, where the transformer is integrated electromagnetically and topologically with the SoBL motor, where an electromagnetic field orientation of the
Non linear system become linear system
Petre Bucur
2007-01-01
Full Text Available The present paper refers to the theory and the practice of the systems regarding non-linear systems and their applications. We aimed the integration of these systems to elaborate their response as well as to highlight some outstanding features.
Linear motor coil assembly and linear motor
2009-01-01
An ironless linear motor (5) comprising a magnet track (53) and a coil assembly (50) operating in cooperation with said magnet track (53) and having a plurality of concentrated multi-turn coils (31 a-f, 41 a-d, 51 a-k), wherein the end windings (31E) of the coils (31 a-f, 41 a-e) are substantially
Dual-range linearized transimpedance amplifier system
Wessendorf, Kurt O.
2010-11-02
A transimpedance amplifier system is disclosed which simultaneously generates a low-gain output signal and a high-gain output signal from an input current signal using a single transimpedance amplifier having two different feedback loops with different amplification factors to generate two different output voltage signals. One of the feedback loops includes a resistor, and the other feedback loop includes another resistor in series with one or more diodes. The transimpedance amplifier system includes a signal linearizer to linearize one or both of the low- and high-gain output signals by scaling and adding the two output voltage signals from the transimpedance amplifier. The signal linearizer can be formed either as an analog device using one or two summing amplifiers, or alternately can be formed as a digital device using two analog-to-digital converters and a digital signal processor (e.g. a microprocessor or a computer).
Linear transformer driver for pulse generation
Kim, Alexander A; Mazarakis, Michael G; Sinebryukhov, Vadim A; Volkov, Sergey N; Kondratiev, Sergey S; Alexeenko, Vitaly M; Bayol, Frederic; Demol, Gauthier; Stygar, William A
2015-04-07
A linear transformer driver includes at least one ferrite ring positioned to accept a load. The linear transformer driver also includes a first power delivery module that includes a first charge storage devices and a first switch. The first power delivery module sends a first energy in the form of a first pulse to the load. The linear transformer driver also includes a second power delivery module including a second charge storage device and a second switch. The second power delivery module sends a second energy in the form of a second pulse to the load. The second pulse has a frequency that is approximately three times the frequency of the first pulse. The at least one ferrite ring is positioned to force the first pulse and the second pulse to the load by temporarily isolating the first pulse and the second pulse from an electrical ground.
Brammer, C.M. Jr.
1977-01-01
Disclosed is a fuel handling guide tube centering device for use in nuclear reactors during fuel assembly handling operations. The device comprises an outer ring secured to the flange of a nuclear reactor pressure vessel, a rotatable table rotatably coupled to the outer ring, and a plurality of openings through the table. Truncated locating cones are positioned in each of the openings in the table, and the locating cones center the guide tube during fuel handling operations. The openings in the table are located such that each fuel assembly in the nuclear core may be aligned with one of the openings by a suitable rotation of the table. The locating cones thereby provide alignment between the fuel handling mechanism located in the guide tube and the individual fuel assemblies of the cone. The need for a device to provide alignment is especially critical for floating nuclear power plants, where wave motion may exist during fuel handling operations. 5 claims, 4 figures
Wiedemann, H.
1981-11-01
Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center.
Blyth, T S
2002-01-01
Basic Linear Algebra is a text for first year students leading from concrete examples to abstract theorems, via tutorial-type exercises. More exercises (of the kind a student may expect in examination papers) are grouped at the end of each section. The book covers the most important basics of any first course on linear algebra, explaining the algebra of matrices with applications to analytic geometry, systems of linear equations, difference equations and complex numbers. Linear equations are treated via Hermite normal forms which provides a successful and concrete explanation of the notion of linear independence. Another important highlight is the connection between linear mappings and matrices leading to the change of basis theorem which opens the door to the notion of similarity. This new and revised edition features additional exercises and coverage of Cramer's rule (omitted from the first edition). However, it is the new, extra chapter on computer assistance that will be of particular interest to readers:...
Wiedemann, H.
1981-11-01
Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center
Matrices and linear transformations
Cullen, Charles G
1990-01-01
""Comprehensive . . . an excellent introduction to the subject."" - Electronic Engineer's Design Magazine.This introductory textbook, aimed at sophomore- and junior-level undergraduates in mathematics, engineering, and the physical sciences, offers a smooth, in-depth treatment of linear algebra and matrix theory. The major objects of study are matrices over an arbitrary field. Contents include Matrices and Linear Systems; Vector Spaces; Determinants; Linear Transformations; Similarity: Part I and Part II; Polynomials and Polynomial Matrices; Matrix Analysis; and Numerical Methods. The first
Efficient Non Linear Loudspeakers
Petersen, Bo R.; Agerkvist, Finn T.
2006-01-01
Loudspeakers have traditionally been designed to be as linear as possible. However, as techniques for compensating non linearities are emerging, it becomes possible to use other design criteria. This paper present and examines a new idea for improving the efficiency of loudspeakers at high levels...... by changing the voice coil layout. This deliberate non-linear design has the benefit that a smaller amplifier can be used, which has the benefit of reducing system cost as well as reducing power consumption....
Faraway, Julian J
2014-01-01
A Hands-On Way to Learning Data AnalysisPart of the core of statistics, linear models are used to make predictions and explain the relationship between the response and the predictors. Understanding linear models is crucial to a broader competence in the practice of statistics. Linear Models with R, Second Edition explains how to use linear models in physical science, engineering, social science, and business applications. The book incorporates several improvements that reflect how the world of R has greatly expanded since the publication of the first edition.New to the Second EditionReorganiz
Fault tolerant linear actuator
Tesar, Delbert
2004-09-14
In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.
Superconducting linear accelerator cryostat
Ben-Zvi, I.; Elkonin, B.V.; Sokolowski, J.S.
1984-01-01
A large vertical cryostat for a superconducting linear accelerator using quarter wave resonators has been developed. The essential technical details, operational experience and performance are described. (author)
Microelectromechanical reprogrammable logic device
Hafiz, M. A. A.; Kosuru, L.; Younis, M. I.
2016-01-01
In modern computing, the Boolean logic operations are set by interconnect schemes between the transistors. As the miniaturization in the component level to enhance the computational power is rapidly approaching physical limits, alternative computing methods are vigorously pursued. One of the desired aspects in the future computing approaches is the provision for hardware reconfigurability at run time to allow enhanced functionality. Here we demonstrate a reprogrammable logic device based on the electrothermal frequency modulation scheme of a single microelectromechanical resonator, capable of performing all the fundamental 2-bit logic functions as well as n-bit logic operations. Logic functions are performed by actively tuning the linear resonance frequency of the resonator operated at room temperature and under modest vacuum conditions, reprogrammable by the a.c.-driving frequency. The device is fabricated using complementary metal oxide semiconductor compatible mass fabrication process, suitable for on-chip integration, and promises an alternative electromechanical computing scheme. PMID:27021295
Microelectromechanical reprogrammable logic device
Hafiz, Md Abdullah Al
2016-03-29
In modern computing, the Boolean logic operations are set by interconnect schemes between the transistors. As the miniaturization in the component level to enhance the computational power is rapidly approaching physical limits, alternative computing methods are vigorously pursued. One of the desired aspects in the future computing approaches is the provision for hardware reconfigurability at run time to allow enhanced functionality. Here we demonstrate a reprogrammable logic device based on the electrothermal frequency modulation scheme of a single microelectromechanical resonator, capable of performing all the fundamental 2-bit logic functions as well as n-bit logic operations. Logic functions are performed by actively tuning the linear resonance frequency of the resonator operated at room temperature and under modest vacuum conditions, reprogrammable by the a.c.-driving frequency. The device is fabricated using complementary metal oxide semiconductor compatible mass fabrication process, suitable for on-chip integration, and promises an alternative electromechanical computing scheme.
Verkerke, Gijsbertus Jacob; Mahieu, H.F.; Geertsema, A.A.; Hermann, I.F.; van Horn, J.R.; Hummel, J. Marjan; van Loon, J.P.; Mihaylov, D.; van der Plaats, A.; Schraffordt Koops, H.; Schutte, H.K.; Veth, R.P.H.; de Vries, M.P.; Rakhorst, G.; Shi, Donglu
2004-01-01
The development of new medical devices is a very time-consuming and costly process. Besides the time between the initial idea and the time that manufacturing and testing of prototypes takes place, the time needed for the development of production facilities, production of test series, marketing,
Grimes, Patrick G.; Einstein, Harry; Bellows, Richard J.
1988-01-12
A tunnel protected electrochemical device features channels fluidically communicating between manifold, tunnels and cells. The channels are designed to provide the most efficient use of auxiliary power. The channels have a greater hydraulic pressure drop and electrical resistance than the manifold. This will provide a design with the optimum auxiliary energy requirements.
If you have a disability or injury, you may use a number of assistive devices. These are tools, products or types of equipment that help you perform tasks and activities. They may help you move around, see, communicate, eat, or get ...
Smith, J.E.
1981-02-27
The present invention is directed to a detection device comprising: (1) an entrance chamber; (2) a central chamber; and (3) an exit chamber. The central chamber includes an ionizing gas, anode, and means for connecting the anode with an external power supply and pulse counter.
Application of laser speckle to randomized numerical linear algebra
Valley, George C.; Shaw, Thomas J.; Stapleton, Andrew D.; Scofield, Adam C.; Sefler, George A.; Johannson, Leif
2018-02-01
We propose and simulate integrated optical devices for accelerating numerical linear algebra (NLA) calculations. Data is modulated on chirped optical pulses and these propagate through a multimode waveguide where speckle provides the random projections needed for NLA dimensionality reduction.
Patten, B.C.
1983-04-01
Two issues concerning linearity or nonlinearity of natural systems are considered. Each is related to one of the two alternative defining properties of linear systems, superposition and decomposition. Superposition exists when a linear combination of inputs to a system results in the same linear combination of outputs that individually correspond to the original inputs. To demonstrate this property it is necessary that all initial states and inputs of the system which impinge on the output in question be included in the linear combination manipulation. As this is difficult or impossible to do with real systems of any complexity, nature appears nonlinear even though it may be linear. A linear system that displays nonlinear behavior for this reason is termed pseudononlinear. The decomposition property exists when the dynamic response of a system can be partitioned into an input-free portion due to state plus a state-free portion due to input. This is a characteristic of all linear systems, but not of nonlinear systems. Without the decomposition property, it is not possible to distinguish which portions of a system's behavior are due to innate characteristics (self) vs. outside conditions (environment), which is an important class of questions in biology and ecology. Some philosophical aspects of these findings are then considered. It is suggested that those ecologists who hold to the view that organisms and their environments are separate entities are in effect embracing a linear view of nature, even though their belief systems and mathematical models tend to be nonlinear. On the other hand, those who consider that organism-environment complex forms a single inseparable unit are implictly involved in non-linear thought, which may be in conflict with the linear modes and models that some of them use. The need to rectify these ambivalences on the part of both groups is indicated.
Cooling device in thermonuclear device
Honda, Tsutomu.
1988-01-01
Purpose: To prevent loss of cooling effect over the entire torus structure directly after accidental toubles in a cooling device of a thermonuclear device. Constitution: Coolant recycling means of a cooling device comprises two systems, which are alternately connected with in-flow pipeways and exit pipeways of adjacent modules. The modules are cooled by way of the in-flow pipeways and the exist pipeways connected to the respective modules by means of the coolant recycling means corresponding to the respective modules. So long as one of the coolant recycling means is kept operative, since every one other modules of the torus structure is still kept cooled, the heat generated from the module put therebetween, for which the coolant recycling is interrupted, is removed by means of heat conduction or radiation from the module for which the cooling is kept continued. No back-up emergency cooling system is required and it can provide high economic reliability. (Kamimura, M.)
Plasma dynamics in a staged pinch device
Khattak, N.A.D.; Ahmed, Z.; Mirza, A.M.; Murtaza, G.
1998-01-01
Plasma parameters in fiber initiated fast and dense theta-pinch plasma driven by an annular finite-thickness gas-puff Z-pinch are studied. The imploding gas-puff Z-pinch plasma traps an axial magnetic field B/sub z/, compressing it to large values (of the order of several megagauss) in an extremely short time. The rapidly changing magnetic flux of this field induces an azimuthal current on the surface of the coaxially placed fiber, with a rise time an order of magnitude shorter than the applied Z-pinch current. The shorter rise time of the current stabilizes the pinch against sausage mode of MHD instabilities. Our numerical results demonstrate that for a relatively thick gas-puff layer, the compression occurs before the current saturates. At the peak compression the fuel densities of the order of 10/sup 25/ cm/sup -3/ and temperature above 10 keV can be achieved on a time scale of 0.1 nanoseconds, yielding the Lawson Criterion parameters n tau is approximately equal to 10/sup 14/ sec cm/sup -3/ for D-T fuel. The snow-plow effect incorporated in our model exercise a strong influence on the onset and growth rate of sausage and Rayleigh-Taylor (R-T) modes of instabilities. Imposing a rotational velocity on the outer thin gas-puff plasma can control the Rayleigh-Taylor instability. Numerical results indicate that the choice of the spin velocity is critical. Large values of the spin velocity, though provide stabilization against the R-T instability at the final stage of compression, however, it adversely reduce the plasma parameters so essential to achieve controlled fusion. Our analysis, therefore, suggests that a judicious choice of the spin velocity is necessary to obtain the desired temperature and density, especially when we seed D-T fiber plasma with a small fraction of high-Z Kr impurity to initiate the radiative collapse. (author)
An adiabatic matching device for the Orsay linear positron accelerator
Chehab, R.; Le Meur, G.; Mouton, B.; Renard, M.
1983-03-01
An adiabatically tapered solenoidal magnetic field is used to match positron beam source emittance to accelerating section acceptance. Such a matching system improves the accepted energy band which has been accurately computed and compared with analytical determination. The tapered field is provided by stacked pancakes and solenoids of various radii; total lens length is about 0.75m. The adiabatic matching system took place of a quarter wave transformer system and has been in operation for two years. Positron conversion ratio is 3.3% for a 1 GeV incident beam and presents a factor of nearly two of improvement for the positron yield. Energy bandwidth of positron beam has also been increased by a factor of nearly 2.5; the output positron beam energy is of 1.2 GeV
single crystal for applications in non-linear optical devices
The unrestricted natural orbital (UNO) is used for the calculation of spin–spin dipolar contributions to the ZFS tensor. A comparative study of the quantum mechanical treatment of Pederson–Khanna (PK) with coupled perturbation (CP) is reported in the present study. The unrestricted Kohn–Sham-based natural orbital with ...
Revisited global drift fluid model for linear devices
Reiser, Dirk
2012-01-01
The problem of energy conserving global drift fluid simulations is revisited. It is found that for the case of cylindrical plasmas in a homogenous magnetic field, a straightforward reformulation is possible avoiding simplifications leading to energetic inconsistencies. The particular new feature is the rigorous treatment of the polarisation drift by a generalization of the vorticity equation. The resulting set of model equations contains previous formulations as limiting cases and is suitable for efficient numerical techniques. Examples of applications on studies of plasma blobs and its impact on plasma target interaction are presented. The numerical studies focus on the appearance of plasma blobs and intermittent transport and its consequences on the release of sputtered target materials in the plasma. Intermittent expulsion of particles in radial direction can be observed and it is found that although the neutrals released from the target show strong fluctuations in their propagation into the plasma column, the overall effect on time averaged profiles is negligible for the conditions considered. In addition, the numerical simulations are utilised to perform an a-posteriori assessment of the magnitude of energetic inconsistencies in previously used simplified models. It is found that certain popular approximations, in particular by the use of simplified vorticity equations, do not significantly affect energetics. However, popular model simplifications with respect to parallel advection are found to provide significant deterioration of the model consistency.
Linear colliders - prospects 1985
Rees, J.
1985-06-01
We discuss the scaling laws of linear colliders and their consequences for accelerator design. We then report on the SLAC Linear Collider project and comment on experience gained on that project and its application to future colliders. 9 refs., 2 figs
Richter, B.
1985-01-01
A report is given on the goals and progress of the SLAC Linear Collider. The author discusses the status of the machine and the detectors and give an overview of the physics which can be done at this new facility. He also gives some ideas on how (and why) large linear colliders of the future should be built
Rogner, H.H.
1989-01-01
The submitted sections on linear programming are extracted from 'Theorie und Technik der Planung' (1978) by W. Blaas and P. Henseler and reformulated for presentation at the Workshop. They consider a brief introduction to the theory of linear programming and to some essential aspects of the SIMPLEX solution algorithm for the purposes of economic planning processes. 1 fig
Rowe, C.H.; Wilton, M.S. de.
1979-01-01
An improved recirculating electron beam linear accelerator of the racetrack type is described. The system comprises a beam path of four straight legs with four Pretzel bending magnets at the end of each leg to direct the beam into the next leg of the beam path. At least one of the beam path legs includes a linear accelerator. (UK)
Semidefinite linear complementarity problems
Eckhardt, U.
1978-04-01
Semidefinite linear complementarity problems arise by discretization of variational inequalities describing e.g. elastic contact problems, free boundary value problems etc. In the present paper linear complementarity problems are introduced and the theory as well as the numerical treatment of them are described. In the special case of semidefinite linear complementarity problems a numerical method is presented which combines the advantages of elimination and iteration methods without suffering from their drawbacks. This new method has very attractive properties since it has a high degree of invariance with respect to the representation of the set of all feasible solutions of a linear complementarity problem by linear inequalities. By means of some practical applications the properties of the new method are demonstrated. (orig.) [de
Axler, Sheldon
2015-01-01
This best-selling textbook for a second course in linear algebra is aimed at undergrad math majors and graduate students. The novel approach taken here banishes determinants to the end of the book. The text focuses on the central goal of linear algebra: understanding the structure of linear operators on finite-dimensional vector spaces. The author has taken unusual care to motivate concepts and to simplify proofs. A variety of interesting exercises in each chapter helps students understand and manipulate the objects of linear algebra. The third edition contains major improvements and revisions throughout the book. More than 300 new exercises have been added since the previous edition. Many new examples have been added to illustrate the key ideas of linear algebra. New topics covered in the book include product spaces, quotient spaces, and dual spaces. Beautiful new formatting creates pages with an unusually pleasant appearance in both print and electronic versions. No prerequisites are assumed other than the ...
Handbook on linear motor application
1988-10-01
This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.
Tezuka, Masaru.
1993-01-01
Protrusions and recesses are formed to a vacuum vessel and toroidal magnetic coils, and they are engaged. Since the vacuum vessel is generally supported firmly by a rack or the like by support legs, the toroidal magnetic field coils can be certainly supported against tumbling force. Then, there can be attained strong supports for the toroidal magnetic field coils, in addition to support by wedges on the side of inboard and support by share panels on the side of outboard, capable of withstanding great electromagnetic forces which may occur in large-scaled next-generation devices. That is, toroidal magnetic field coils excellent from a view point of deformation and stress can be obtained, to provide a thermonuclear device of higher reliability. (N.H.)
Oosaki, Osamu; Masuda, Kenju.
1980-01-01
Purpose: To provide excellent electric properties and high reliability in a thermonuclear device by improving a current collecting board connected to a coil device. Constitution: A current collecting board element perforated with an opening for enserting a connecting terminal is sized to be inserted into a plating tank, and is surface treated in the plating tank. Only the current collecting board element preferably surface treated is picked up. A plurality of such current collecting board elements are connected and welded to form a large current collecting board. In this manner, the current collecting board having several m 2 to several ten order m 2 in area can be obtained as preferably surface treated at the connecting terminal hole. The current collecting board element can be determined in shape with the existing facility without increasing the size of a surface treating tank. (Kamimura, M.)
Yagi, Yasuomi; Takahashi, Ken; Hashimoto, Hiroshi.
1984-01-01
Purpose: To improve the plasma confining performances by bringing the irregular magnetic fields nearly to zero and decreasing the absolute value of the irregular magnetic fields at every positions. Constitution: The winding direction of a plurality of coil elements, for instance, double pan cake coils of toroidal coils in a torus type or mirror type thermonuclear device are reversed to each other in their laminating direction, whereby the irregular magnetic fields due to the coil-stepped portions in each toroidal coils are brought nearly to zero. This enables to bring the average irregular magnetic fields as a whole in the thermonuclear device nearly to zero, as well as, decrease the absolute value of the irregular magnetic fields in each positions. Thus, the plasma confining performances can be improved. (Moriyama, K.)
CERN PhotoLab
1965-01-01
The alignment of one of the accelerator magnets being checked by the AR Division survey group. A "distinvar" device, invented by the group, using calibrated invar wires stretched between the fixed survey pillar (on the left) and a fixed point on the magnet. In two days it is thus possible to measure the alignment of the 100 magnets with an accuracy better than 1/10.
Ulrich, G. W. (Inventor)
1975-01-01
A latching device is suited for use in establishing a substantially motionless connection between a stationary receiver and a movable latching mechanism. The latching mechanism includes a pivotally supported restraining hook continuously urged into a capturing relationship with the receiver, characterized by a spring-biased pawl having a plurality of aligned teeth. The teeth are seated in the surface of the throat of the hook and positionable into restraining engagement with a rigid restraining shoulder projected from the receiver.
Linear ubiquitination in immunity.
Shimizu, Yutaka; Taraborrelli, Lucia; Walczak, Henning
2015-07-01
Linear ubiquitination is a post-translational protein modification recently discovered to be crucial for innate and adaptive immune signaling. The function of linear ubiquitin chains is regulated at multiple levels: generation, recognition, and removal. These chains are generated by the linear ubiquitin chain assembly complex (LUBAC), the only known ubiquitin E3 capable of forming the linear ubiquitin linkage de novo. LUBAC is not only relevant for activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) in various signaling pathways, but importantly, it also regulates cell death downstream of immune receptors capable of inducing this response. Recognition of the linear ubiquitin linkage is specifically mediated by certain ubiquitin receptors, which is crucial for translation into the intended signaling outputs. LUBAC deficiency results in attenuated gene activation and increased cell death, causing pathologic conditions in both, mice, and humans. Removal of ubiquitin chains is mediated by deubiquitinases (DUBs). Two of them, OTULIN and CYLD, are constitutively associated with LUBAC. Here, we review the current knowledge on linear ubiquitination in immune signaling pathways and the biochemical mechanisms as to how linear polyubiquitin exerts its functions distinctly from those of other ubiquitin linkage types. © 2015 The Authors. Immunological Reviews Published by John Wiley & Sons Ltd.
Krivonos, S.O.; Sorin, A.S.
1994-06-01
We show that the Zamolodchikov's and Polyakov-Bershadsky nonlinear algebras W 3 and W (2) 3 can be embedded as subalgebras into some linear algebras with finite set of currents. Using these linear algebras we find new field realizations of W (2) 3 and W 3 which could be a starting point for constructing new versions of W-string theories. We also reveal a number of hidden relationships between W 3 and W (2) 3 . We conjecture that similar linear algebras can exist for other W-algebra as well. (author). 10 refs
Schneider, Hans
1989-01-01
Linear algebra is one of the central disciplines in mathematics. A student of pure mathematics must know linear algebra if he is to continue with modern algebra or functional analysis. Much of the mathematics now taught to engineers and physicists requires it.This well-known and highly regarded text makes the subject accessible to undergraduates with little mathematical experience. Written mainly for students in physics, engineering, economics, and other fields outside mathematics, the book gives the theory of matrices and applications to systems of linear equations, as well as many related t
Linearity in Process Languages
Nygaard, Mikkel; Winskel, Glynn
2002-01-01
The meaning and mathematical consequences of linearity (managing without a presumed ability to copy) are studied for a path-based model of processes which is also a model of affine-linear logic. This connection yields an affine-linear language for processes, automatically respecting open......-map bisimulation, in which a range of process operations can be expressed. An operational semantics is provided for the tensor fragment of the language. Different ways to make assemblies of processes lead to different choices of exponential, some of which respect bisimulation....
Amir-Moez, A R; Sneddon, I N
1962-01-01
Elements of Linear Space is a detailed treatment of the elements of linear spaces, including real spaces with no more than three dimensions and complex n-dimensional spaces. The geometry of conic sections and quadric surfaces is considered, along with algebraic structures, especially vector spaces and transformations. Problems drawn from various branches of geometry are given.Comprised of 12 chapters, this volume begins with an introduction to real Euclidean space, followed by a discussion on linear transformations and matrices. The addition and multiplication of transformations and matrices a
Weisberg, Sanford
2013-01-01
Praise for the Third Edition ""...this is an excellent book which could easily be used as a course text...""-International Statistical Institute The Fourth Edition of Applied Linear Regression provides a thorough update of the basic theory and methodology of linear regression modeling. Demonstrating the practical applications of linear regression analysis techniques, the Fourth Edition uses interesting, real-world exercises and examples. Stressing central concepts such as model building, understanding parameters, assessing fit and reliability, and drawing conclusions, the new edition illus
Next generation toroidal devices
Yoshikawa, Shoichi
1998-10-01
A general survey of the possible approach for the next generation toroidal devices was made. Either surprisingly or obviously (depending on one's view), the technical constraints along with the scientific considerations lead to a fairly limited set of systems for the most favorable approach for the next generation devices. Specifically if the magnetic field strength of 5 T or above is to be created by superconducting coils, it imposes minimum in the aspect ratio for the tokamak which is slightly higher than contemplated now for ITER design. The similar technical constraints make the minimum linear size of a stellarator large. Scientifically, it is indicated that a tokamak of 1.5 times in the linear dimension should be able to produce economically, especially if a hybrid reactor is allowed. For the next stellarator, it is strongly suggested that some kind of helical axis is necessary both for the (almost) absolute confinement of high energy particles and high stability and equilibrium beta limits. The author still favors a heliac most. Although it may not have been clearly stated in the main text, the stability afforded by the shearless layer may be exploited fully in a stellarator. (author)
Next generation toroidal devices
Yoshikawa, Shoichi [Princeton Plasma Physics Lab., Princeton Univ., NJ (United States)
1998-10-01
A general survey of the possible approach for the next generation toroidal devices was made. Either surprisingly or obviously (depending on one`s view), the technical constraints along with the scientific considerations lead to a fairly limited set of systems for the most favorable approach for the next generation devices. Specifically if the magnetic field strength of 5 T or above is to be created by superconducting coils, it imposes minimum in the aspect ratio for the tokamak which is slightly higher than contemplated now for ITER design. The similar technical constraints make the minimum linear size of a stellarator large. Scientifically, it is indicated that a tokamak of 1.5 times in the linear dimension should be able to produce economically, especially if a hybrid reactor is allowed. For the next stellarator, it is strongly suggested that some kind of helical axis is necessary both for the (almost) absolute confinement of high energy particles and high stability and equilibrium beta limits. The author still favors a heliac most. Although it may not have been clearly stated in the main text, the stability afforded by the shearless layer may be exploited fully in a stellarator. (author)
A beam scraper using a linear motor
Beadle, E.R.; Rodger, E.S.; Thern, R.E.
1989-01-01
A beam scraper using a linear motor drive has been developed for use in the AGS at Brookhaven National Laboratory. The device is used to measure beam size by moving a target to a predetermined location and measuring the intercepted beam with nearby loss monitors or by noting the decrease in the circulating beam current. This device has excellent vacuum characteristics, as the motor and sensor coils are outside the vacuum, coupled magnetically to the moving parts which, are inside. There are no bellows or dynamic seals required. The position-time profile is controlled by a closed-loop servo system which uses position feedback. 2 refs., 4 figs
Callier, Frank M.; Desoer, Charles A.
1991-01-01
The aim of this book is to provide a systematic and rigorous access to the main topics of linear state-space system theory in both the continuous-time case and the discrete-time case; and the I/O description of linear systems. The main thrusts of the work are the analysis of system descriptions and derivations of their properties, LQ-optimal control, state feedback and state estimation, and MIMO unity-feedback systems.
Inoue, Toyokazu; Murata, Toru.
1983-01-01
Purpose: To shield superconducting coils for use in the generation of magnetic field against neutron irradiation thereby preventing tritium contamination. Constitution: The thermonuclear device comprises, in its inside, a vacuum container for containing plasmas, superconducting coils disposed to the outside of the vacuum container and neutron absorbers disposed between the super-conducting coils and the vacuum container. since neutrons issued from the plasma are absorbed by neutron absorbers and not irradiated to the superconducting coils, generation of tritium due to the reaction between 3 He in the liquid helium as the coolants for the super-conducting coils and the neutrons is prevented. (Aizawa, K.)
Mokuya, Kenji.
1975-01-01
Object: To provide a strainer device, which is adapted to facilitate flushing and is particularly suited for installation in the cooling system of a liquid metal cooled fast breeding reactor. Structure: A casing accommodating a strainer and a blind plate for the selection of a flow path is provided at a suitable portion of the duct line. The blind plate is adapted to be rotated by an opening and closing means consisting of a rod. bellows, shaft and so forth. At the time of flushing, the duct line is sealed by the blind plate. (Nakamura, S.)
Jacoby, B.A.; York, T.M.
1979-02-01
With the presumption that a shifted Maxwellian velocity distribution adequately describes the electrons in a flowing plasma, the details of a method to measure their directed velocity are described. The system consists of a ruby laser source and two detectors set 180 0 from each other and both set at 90 0 with respect to the incident laser beam. The lowest velocity that can be determined by this method depends on the electron thermal velocity. The application of this diagnostic to the measurement of flow velocities in plasma being lost from the ends of theta-pinch devices is described
Relative measurement of the excitation rate coefficients of the FeXI ion
Marotta, A.
1982-01-01
The collision rate coefficients for the iron atoms are measured through the hot plasma obtainment. The physical model used in this determination is the crown stationary model which consider that the excitation by electronic collisions is balanced by the spontaneous emission. This work was realized in a 15Kj theta pinch device, of high pulse reproductibility. The iron-pentacarbonyl [Fe(Co) 5 ] was used as the impurity source of a hydrogen gas. The temperature and density were determined by the scattering light analysis of a rubi laser using the Thomson scattering. (L.C.) [pt
Implosion and staging systems for a Scyllac Fusion Test Reactor
Gribble, R.F.; Linford, R.K.; Thomassen, K.I.
1976-01-01
The implosion heating and adiabatic compression processes will be separated in future theta pinch devices. The circuit to achieve the fast implosion heating and power crowbar (staging) for the Scyllac Fusion Test Reactor is described here. The plasma is very tightly coupled to the circuit and presents a varying inductive load. Computer-aided circuit designs which achieve a programmed magnetic field waveform are described. The field approximates a two-step waveform, on-off-on, which is ideal for achieving the large initial plasma radius needed for stability. The components for the circuits have been developed and are being tested in experiments at Los Alamos
Implosion and staging systems for a Scyllac fusion test reactor
Gribble, R.F.; Linford, R.K.; Thomassen, K.I.
1975-01-01
The implosion heating and adiabatic compression processes will be separated in future theta pinch devices. The circuit to achieve the fast implosion heating and power crowbar (staging) for the Scyllac Fusion Test Reactor is described here. The plasma is very tightly coupled to the circuit and presents a varying inductive load. Computer-aided circuit designs which achieve a programmed magnetic field waveform are described. The field approximates a two-step waveform, on-off-on, which is ideal for achieving the large initial plasma radius needed for stability. The components for the circuits have been developed and are being tested in experiments at Los Alamos. (auth)
Conceptual design study of a scyllac fusion test reactor
Thomassen, K.I.
1975-07-01
The report describes a conceptual design study of a fusion test reactor based on the Scyllac toroidal theta-pinch approach to fusion. It is not the first attempt to describe the physics and technology required for demonstrating scientific feasibility of the approach, but it is the most complete design in the sense that the physics necessary to achieve the device goals is extrapolated from experimentally tested MHD theories of toroidal systems,and it uses technological systems whose engineering performance has been carefully calculated to ensure that they meet the machine requirements
York, T.M.
1986-01-01
The subject contract research effort was initiated in September 1976 with two specific tasks: (1) to study the fundamental physics of confinement of an alternate concept (i.e., theta pinch based) devices; and (2) to study and to develop new diagnostic systems for use on major experiments at other locations in the country. There has been active collaboration with Los Alamos National Laboratory and Lawrence Livermore National Laboratory; there has been proposed collaboration with Princeton Plasma Physics Laboratory, Fusion Research Center at the University of Texas, and General Atomics
Radiolytic production of chemical fuels in fusion reactor systems
Fish, J D
1977-06-01
Miley's energy flow diagram for fusion reactor systems is extended to include radiolytic production of chemical fuel. Systematic study of the economics and the overall efficiencies of fusion reactor systems leads to a criterion for evaluating the potential of radiolytic production of chemical fuel as a means of enhancing the performance of a fusion reactor system. The ecumenicity of the schema is demonstrated by application to (1) tokamaks, (2) mirror machines, (3) theta-pinch reactors, (4) laser-heated solenoids, and (5) inertially confined, laser-pellet devices. Pure fusion reactors as well as fusion-fission hybrids are considered.
Radiolytic production of chemical fuels in fusion reactor systems
Fish, J.D.
1977-06-01
Miley's energy flow diagram for fusion reactor systems is extended to include radiolytic production of chemical fuel. Systematic study of the economics and the overall efficiencies of fusion reactor systems leads to a criterion for evaluating the potential of radiolytic production of chemical fuel as a means of enhancing the performance of a fusion reactor system. The ecumenicity of the schema is demonstrated by application to (1) tokamaks, (2) mirror machines, (3) theta-pinch reactors, (4) laser-heated solenoids, and (5) inertially confined, laser-pellet devices. Pure fusion reactors as well as fusion-fission hybrids are considered
Krüger, Jens J.
2014-01-01
In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.
Honda, Takuro; Maki, Koichi.
1997-01-01
The present invention provides a thermonuclear device, in which integrity of a measuring device is kept, the reactor wall temperature and wear of armour materials are monitored accurately even under intense radiation rays, so that the flow rate of coolants and plasma power can be controlled by using the signals. Infrared rays generated from the surface of the armour materials disposed on a first wall are detected to measure the reactor wall temperature. Coolant flow rate and plasma power are controlled based on the obtained reactor wall temperature. In addition, infrared rays generated from the back of the armour materials are detected to obtain the surface temperature in order to avoid intense radiation rays from plasmas. The coolant flow rate and the plasma power are controlled based on the obtained temperature on the surface of the reactor thereby controlling the temperature of the first wall and the armour material to 300degC or lower in a case of the first wall made of stainless steel and 1000degC or lower in a case of the armour material made of graphite. (I.S.)
Kuriyama, Masaaki; Yamamoto, Masahiro; Furuyama, Masayuki; Saito, Ryusei.
1981-01-01
Purpose: To enable the efficient and rapid cooling of a vacuum vessel by cooling with gas when the temperature of the vacuum vessel is higher than the boiling point of water and cooling with water when the temperature is lower than the boiling point of water. Constitution: A cooling pipe is provided through an insulating pipe on the outer periphery of a vacuum vessel. The cooling pipe communicates through a cooling gas valve and a coolant valve with a cooling gas supply device and a coolant supply device, and a heat exchanger is disposed at the pipe. When the vessel is higher than the boiling point of the coolant the coolant valve is closed and the cooling gas valve is opened and gas is supplied to cool the vessel. The gas is recoverd through a heat exchanger. On the other hand, when the temperature of vessel is lower than the boiling point of the coolant, the gas valve is closed, the coolant valve is opened, and the vessel is cooled with coolant. The vacuum vessel can be cooled for short time employing both the gas and the coolant together. (Yoshino, Y.)
Takano, Hirohisa; Nakamoto, Kazunari; Hanai, Satoshi.
1984-01-01
Purpose: To provide coils of high mechanical strength for use at the center of a torus type thermonuclear device. Constitution: A plurality of copper plates having cooling holes and bolt holes and insulation paper sheets of the same shape are prepared. The copper plate is different from the insulation paper sheet only in that the position-phase angle of the opening portion is larger by 15 - 30 0 . The copper plates and the insulation paper sheets are alternately stacked by a required number of turns while displacing the angle, and then clamped by bolts to form a mechanically strong coil with no metallurgical joining. Further, since the insulation paper sheets are not present in the radial direction and only one insulation paper sheet is inserted for each turn in the direction of the coil height, the space occupied by the coil can be decreased. According to this invention, the magnetic flux density at the center of the device can be increased as compared with the conventional case to thereby apply a higher voltage on the side of plasmas. (Moriyama, K.)
Suzuki, Toshimitsu.
1989-01-01
In an irradiation device for irradiating radiation rays such as electron beams to pharmaceuticals, etc., since the distribution of scanned electron rays was not monitored, the electron beam intensity could be determined only indirectly and irradiation reliability was not satisfactory. In view of the above, a plurality of monitor wires emitting secondary electrons are disposed in the scanning direction near a beam take-out window of a scanning duct, signals from the monitor wires are inputted into a display device such as a cathode ray tube, as well as signals from the monitor wires at the central portion are inputted into counting rate meters to measure the radiation dose as well. Since secondary electrons are emitted when electron beams pass through the monitor wires and the intensity thereof is in proportion with the intensity of incident electron beams, the distribution of the radiation dose can be monitored by measuring the intensity of the emitted secondary electrons. Further, uneven irradiation, etc. can also be monitored to make the radiation of irradiation rays reliable. (N.H.)
Performance of ALVAND 1. capacitor bank
Torabi-fard, A.; Farahani, M.; Ebrani, M.; Rostami, R.; Daghighian, F.
1978-01-01
This report describes the specifications of the capacitor bank for the ALVAND I, Linear theta pinch experiment and the results of some tests performed on it. A one-meter-wide module includes the basic components such as capacitors, Spark gaps, and crowbar triggers. Complementary parts such as ground system, pressurised dry air system and safety system were added. With a rise-time of about three micro-seconds and a total current of six million amperes it is possible to produce ion temperature in excess of one kev for a few microseconds. Different probes were used to measure the magnetic field and the total current
Blyth, T S
2002-01-01
Most of the introductory courses on linear algebra develop the basic theory of finite dimensional vector spaces, and in so doing relate the notion of a linear mapping to that of a matrix. Generally speaking, such courses culminate in the diagonalisation of certain matrices and the application of this process to various situations. Such is the case, for example, in our previous SUMS volume Basic Linear Algebra. The present text is a continuation of that volume, and has the objective of introducing the reader to more advanced properties of vector spaces and linear mappings, and consequently of matrices. For readers who are not familiar with the contents of Basic Linear Algebra we provide an introductory chapter that consists of a compact summary of the prerequisites for the present volume. In order to consolidate the student's understanding we have included a large num ber of illustrative and worked examples, as well as many exercises that are strategi cally placed throughout the text. Solutions to the ex...
Practical microwave electron devices
Meurant, Gerard
2013-01-01
Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.
Control system and method for prosthetic devices
Bozeman, Richard J., Jr. (Inventor)
1992-01-01
A control system and method for prosthetic devices is provided. The control system comprises a transducer for receiving movement from a body part for generating a sensing signal associated with that movement. The sensing signal is processed by a linearizer for linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part. The linearized sensing signal is normalized to be a function of the entire range of body part movement from the no-shrug position of the movable body part through the full-shrug position of the movable body part. The normalized signal is divided into a plurality of discrete command signals. The discrete command signals are used by typical converter devices which are in operational association with the prosthetic device. The converter device uses the discrete command signals for driving the movable portions of the prosthetic device and its sub-prosthesis. The method for controlling a prosthetic device associated with the present invention comprises the steps of receiving the movement from the body part, generating a sensing signal in association with the movement of the body part, linearizing the sensing signal to be a linear function of the magnitude of the distance moved by the body part, normalizing the linear signal to be a function of the entire range of the body part movement, dividing the normalized signal into a plurality of discrete command signals, and implementing the plurality of discrete command signals for driving the respective movable prosthesis device and its sub-prosthesis.
Olver, Peter J
2018-01-01
This textbook develops the essential tools of linear algebra, with the goal of imparting technique alongside contextual understanding. Applications go hand-in-hand with theory, each reinforcing and explaining the other. This approach encourages students to develop not only the technical proficiency needed to go on to further study, but an appreciation for when, why, and how the tools of linear algebra can be used across modern applied mathematics. Providing an extensive treatment of essential topics such as Gaussian elimination, inner products and norms, and eigenvalues and singular values, this text can be used for an in-depth first course, or an application-driven second course in linear algebra. In this second edition, applications have been updated and expanded to include numerical methods, dynamical systems, data analysis, and signal processing, while the pedagogical flow of the core material has been improved. Throughout, the text emphasizes the conceptual connections between each application and the un...
Banach, S
1987-01-01
This classic work by the late Stefan Banach has been translated into English so as to reach a yet wider audience. It contains the basics of the algebra of operators, concentrating on the study of linear operators, which corresponds to that of the linear forms a1x1 + a2x2 + ... + anxn of algebra.The book gathers results concerning linear operators defined in general spaces of a certain kind, principally in Banach spaces, examples of which are: the space of continuous functions, that of the pth-power-summable functions, Hilbert space, etc. The general theorems are interpreted in various mathematical areas, such as group theory, differential equations, integral equations, equations with infinitely many unknowns, functions of a real variable, summation methods and orthogonal series.A new fifty-page section (``Some Aspects of the Present Theory of Banach Spaces'''') complements this important monograph.
Høskuldsson, Agnar
1996-01-01
Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four of these cri......Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four...... the basic problems in determining the dimension of linear models. Then each of the eight measures are treated. The results are illustrated by examples....
Linear programming using Matlab
Ploskas, Nikolaos
2017-01-01
This book offers a theoretical and computational presentation of a variety of linear programming algorithms and methods with an emphasis on the revised simplex method and its components. A theoretical background and mathematical formulation is included for each algorithm as well as comprehensive numerical examples and corresponding MATLAB® code. The MATLAB® implementations presented in this book are sophisticated and allow users to find solutions to large-scale benchmark linear programs. Each algorithm is followed by a computational study on benchmark problems that analyze the computational behavior of the presented algorithms. As a solid companion to existing algorithmic-specific literature, this book will be useful to researchers, scientists, mathematical programmers, and students with a basic knowledge of linear algebra and calculus. The clear presentation enables the reader to understand and utilize all components of simplex-type methods, such as presolve techniques, scaling techniques, pivoting ru...
Anon.
1994-01-01
The aim of the TESLA (TeV Superconducting Linear Accelerator) collaboration (at present 19 institutions from seven countries) is to establish the technology for a high energy electron-positron linear collider using superconducting radiofrequency cavities to accelerate its beams. Another basic goal is to demonstrate that such a collider can meet its performance goals in a cost effective manner. For this the TESLA collaboration is preparing a 500 MeV superconducting linear test accelerator at the DESY Laboratory in Hamburg. This TTF (TESLA Test Facility) consists of four cryomodules, each approximately 12 m long and containing eight 9-cell solid niobium cavities operating at a frequency of 1.3 GHz
Design of microwave active devices
Gautier , Jean-Luc
2014-01-01
This book presents methods for the design of the main microwave active devices. The first chapter focuses on amplifiers working in the linear mode. The authors present the problems surrounding narrowband and wideband impedance matching, stability, polarization and the noise factor, as well as specific topologies such as the distributed amplifier and the differential amplifier. Chapter 2 concerns the power amplifier operation. Specific aspects on efficiency, impedance matching and class of operation are presented, as well as the main methods of linearization and efficiency improvement. Freq
Production and analysis of thermonuclear plasmas in high beta devices. Progress report
1976-01-01
During the October 1975--July 1976 reporting period, significant progress was reported in all ongoing projects funded by ERDA. Construction of the major new experiment THOR was delayed due to difficulties in bringing the Maxwell Laboratory swinging LC-pulse generators up to specifications. These technical difficulties have now been overcome and the pulsers were accepted late in April. THOR is almost back on schedule and physics results on plasma heating are expected by September of this year. TERP, originally funded as an Exploratory Concept, has been operating successfully for over a year and given confinement physics results which are important for the development of Maximum Beta Tokamaks. The Measurement and Instrumentation efforts have resulted in a number of instrument developments that have been successfully tested on FTP or STP, our fast or small theta pinches. Both FTP and STP were studied intensively to obtain ion and electron heating rates and anomalous post-implosion resistivities. These results are supported by the University of Maryland theory and simulation programs and SAI
Furuyama, Masayuki.
1979-01-01
Purpose: To provide the subject device wherein a conductive short-circuiting ring is installed in the vicinity of the bonded part of bellows and thick portion of vacuum vessel in the small circumferential direction of torus, thereby to reduce the electromagnetic force generated at the bellows. Constitution: A conductive short-circuiting ring is provided in the vicinity of the connected part of a thick portion and bellows portion. By this organization, a saddle type current generated at the thick portion by a vertical magnetic field flows through the short-circuiting ring because the resistance at a part where the short-circuiting ring is provided is reduced, and the current flowing through the bellows is remarkably reduced. For this reason, the electromagnetic force generated at the bellows is reduced thereby to prevent the bellows from being destroyed by the electromagnetic force. (Yoshihara, H.)
Rhodes, P. H.; Snyder, R. S. (Inventor)
1982-01-01
A device for separating cellular particles of a sample substance into fractionated streams of different cellular species includes a casing having a distribution chamber, a separation chamber, and a collection chamber. The electrode chambers are separated from the separation chamber interior by means of passages such that flow variations and membrane variations around the slotted portion of the electrode chamber do not enduce flow perturbations into the laminar buffer curtain flowing in the separation chamber. The cellular particles of the sample are separated under the influence of the electrical field and the separation chamber into streams of different cellular species. The streams of separated cells enter a partition array in the collection chamber where they are fractionated and collected.
Suzuki, Shohei
1988-01-01
Purpose: To obtain high voltage withstanding current introduction terminals not suffering from the effects of the reduction in the creeping voltage withstanding property by the application of magnetic fields. Constitution: This invention concerns a current introduction terminal for supplying electric current to coils for use in a thermonuclear device, etc. The conductor of the current introduction terminal on the side of vacuum is completely covered with solid insulator. This can eliminate the portion of securing the creeping withstanding voltage. The voltage withstanding characteristics of the solid insulator covering the portion of the conductor on the side of vacuum has a constant value irrespective of the atmosphere or the absence or presence of magnetic fields. Accordingly, the voltage withstanding characteristics of the current introduction terminal on the side of vacuum are determined by the property of the solid insulator, which is not reduced by the application of magnetic fields. (Ikeda, J.)
Linearly Adjustable International Portfolios
Fonseca, R. J.; Kuhn, D.; Rustem, B.
2010-09-01
We present an approach to multi-stage international portfolio optimization based on the imposition of a linear structure on the recourse decisions. Multiperiod decision problems are traditionally formulated as stochastic programs. Scenario tree based solutions however can become intractable as the number of stages increases. By restricting the space of decision policies to linear rules, we obtain a conservative tractable approximation to the original problem. Local asset prices and foreign exchange rates are modelled separately, which allows for a direct measure of their impact on the final portfolio value.
Linearly Adjustable International Portfolios
Fonseca, R. J.; Kuhn, D.; Rustem, B.
2010-01-01
We present an approach to multi-stage international portfolio optimization based on the imposition of a linear structure on the recourse decisions. Multiperiod decision problems are traditionally formulated as stochastic programs. Scenario tree based solutions however can become intractable as the number of stages increases. By restricting the space of decision policies to linear rules, we obtain a conservative tractable approximation to the original problem. Local asset prices and foreign exchange rates are modelled separately, which allows for a direct measure of their impact on the final portfolio value.
Barkman, W.E.; Adams, W.Q.; Berrier, B.R.
1978-01-01
A linear induction motor has been operated on a test bed with a feedback pulse resolution of 5 nm (0.2 μin). Slewing tests with this slide drive have shown positioning errors less than or equal to 33 nm (1.3 μin) at feedrates between 0 and 25.4 mm/min (0-1 ipm). A 0.86-m (34-in)-stroke linear motor is being investigated, using the SPACO machine as a test bed. Initial results were encouraging, and work is continuing to optimize the servosystem compensation
Hogben, Leslie
2013-01-01
With a substantial amount of new material, the Handbook of Linear Algebra, Second Edition provides comprehensive coverage of linear algebra concepts, applications, and computational software packages in an easy-to-use format. It guides you from the very elementary aspects of the subject to the frontiers of current research. Along with revisions and updates throughout, the second edition of this bestseller includes 20 new chapters.New to the Second EditionSeparate chapters on Schur complements, additional types of canonical forms, tensors, matrix polynomials, matrix equations, special types of
Linear Algebra Thoroughly Explained
Vujičić, Milan
2008-01-01
Linear Algebra Thoroughly Explained provides a comprehensive introduction to the subject suitable for adoption as a self-contained text for courses at undergraduate and postgraduate level. The clear and comprehensive presentation of the basic theory is illustrated throughout with an abundance of worked examples. The book is written for teachers and students of linear algebra at all levels and across mathematics and the applied sciences, particularly physics and engineering. It will also be an invaluable addition to research libraries as a comprehensive resource book for the subject.
Safety device of thermonuclear device
Aoki, Isao; Ueda, Shuzo; Seki, Yasushi; Sakurai, Akiko; Kasahara, Fumio; Obara, Atsushi; Yamauchi, Michinori.
1997-01-01
The present invention provides a safety device against an event of intrusion of coolants in a vacuum vessel. Namely, a coolant supply system comprises cooling tubes for supplying coolants to main reactor structure components including a vacuum vessel. A detection means detects leakage of coolants in the vacuum vessel. A coolant supply control means controls the supply of coolants to the main reactor structural components based on the leakage detection signals of the detection means. A stagnated material discharging means discharges stagnated materials in the main reactor structural components caused by the leakage of coolants. The leakage of coolants (for example, water) in the vacuum vessel can thus be detected by the water detection device in the vacuum vessel. A control value of a coolant supply means is closed by the leakage detection signals. The supply of coolants to the main reactor structural components is restricted to suppress the leakage. The stagnated materials are discharged to a tank by way of a water draining valve. (I.S.)
2013-05-10
AND VICTIM- ~ vAP BLAMING 4. AMERICA, LINEARLY CYCUCAL AF IMT 1768, 19840901, V5 PREVIOUS EDITION WILL BE USED. C2C Jessica Adams Dr. Brissett...his desires, his failings, and his aspirations follow the same general trend throughout history and throughout cultures. The founding fathers sought
Southworth, B.
1985-01-01
The peak of the construction phase of the Stanford Linear Collider, SLC, to achieve 50 GeV electron-positron collisions has now been passed. The work remains on schedule to attempt colliding beams, initially at comparatively low luminosity, early in 1987. (orig./HSI).
Mafra Neto, F.
1992-01-01
The dose of gamma radiation from a linear source of cesium 137 is obtained, presenting two difficulties: oblique filtration of radiation when cross the platinum wall, in different directions, and dose connection due to the scattering by the material mean of propagation. (C.G.C.)
Resistors Improve Ramp Linearity
Kleinberg, L. L.
1982-01-01
Simple modification to bootstrap ramp generator gives more linear output over longer sweep times. New circuit adds just two resistors, one of which is adjustable. Modification cancels nonlinearities due to variations in load on charging capacitor and due to changes in charging current as the voltage across capacitor increases.
LINEAR COLLIDERS: 1992 workshop
Settles, Ron; Coignet, Guy
1992-01-01
As work on designs for future electron-positron linear colliders pushes ahead at major Laboratories throughout the world in a major international collaboration framework, the LC92 workshop held in Garmisch Partenkirchen this summer, attended by 200 machine and particle physicists, provided a timely focus
Brameier, Markus
2007-01-01
Presents a variant of Genetic Programming that evolves imperative computer programs as linear sequences of instructions, in contrast to the more traditional functional expressions or syntax trees. This book serves as a reference for researchers, but also contains sufficient introduction for students and those who are new to the field
Dobbs, David E.
2013-01-01
A direct method is given for solving first-order linear recurrences with constant coefficients. The limiting value of that solution is studied as "n to infinity." This classroom note could serve as enrichment material for the typical introductory course on discrete mathematics that follows a calculus course.
Takeda, Seishi
1992-01-01
The status of R and D of future e + e - linear colliders proposed by the institutions throughout the world is described including the JLC, NLC, VLEPP, CLIC, DESY/THD and TESLA projects. The parameters and RF sources are discussed. (G.P.) 36 refs.; 1 tab
Kumar, Putha Suman; Banerjee, S; Arun Kumar, E S; Srinivas, Challapalli; Vadhiraja, B M; Saxena, P U; Ravichandran, Ramamoorthy; Kasturi, Dinesh Pai
2018-01-01
This study presents a method to estimate midplane dose (D iso, transit ) in vivo from transit signal (S t ) measured with thimble ionization chamber in cancer of the middle-third esophagus patients treated with three-dimensional radiotherapy (RT). This detector is positioned at the level of electronic portal imaging device in the gantry of a medical linear accelerator. Efficacy of inhomogeneity corrections of three dose calculation algorithms available in XiO treatment planning system (TPS) for planned dose (for open fields) (D iso, TPS ) was studied with three heterogeneous phantoms. D iso, transit represents measured signal at transit point (S t ) far away correlating to dose at isocenter. A locally fabricated thorax phantom was used to measure the in vivo midplane dose (D iso, mid ) which was also estimated through S t . Thirteen patients with carcinoma of the middle-third esophagus treated with three-dimensional conformal RT were studied. S t was recorded (three times, with a gap of 5-6 fractions during the treatment) to estimate D iso, transit , which was compared with the doses calculated by TPS. The dose predictions by superposition algorithm were superior compared to the other algorithms. Percentage deviation of D iso, transit , D iso, mid with D iso, TPS combined all fields was 2.7 and -2.6%, respectively, with the thorax phantom. The mean percentage deviation with standard deviation of estimated D iso, transit with D iso, TPS observed in patients was within standard deviation -0.73% ±2.09% (n = 39). Midplane dose estimates in vivo using this method provide accurate determination of delivered dose in the middle-third esophagus RT treatments. This method could be useful in similar clinical circumstances for dose confirmation and documentation.
Suzuki, Shohei.
1980-01-01
Purpose: To improve the plasma confining efficiency in a thermonuclear device having magnet coils using super-conducting wires by decreasing the uneven magnetic field resulted from current supply terminals and wirings. Constitution: Current introduction terminals of magnet coils using superconducting wires are short circuitted with a superconducting short circuit wire. Upon supplying current to the coils, the resistance of the coils is rendered superconductive and the resistance of the short circuit wire is rendered normally conductive heated by a heater and the switch is closed. In this case, most parts of the current are flown through the resistance of the coils and the switch is opened when the current arrives at a predetermined value to render the resistance of the short circuit wire superconductive. Then, the current transfers from the thyristor power source to the resistance of the short circuit wire, whereby the resistance of the coils and that of the short circuit wire from a permanent current loop. In this conditions, since current flows through the short circuit wire and the coils and not to the current introduction terminals, no uniform magnetic field is generated. (Kawakami, Y.)
Claridge, A.N.; Smith, A.J.
1983-01-01
A reluctance device comprises two or more phases, each of which has a rotor mounted for rotation within a tubular member and an annular stator positioned externally of the tubular member. The rotor and the internal surface of the tubular member are each provided with aligned, axially spaced apart annular arrays of teeth, the teeth on the rotor confronting those on the tubular member in radially spaced apart relationship. The stator encloses a coil which, when electrically energised, creates a plurality of magnetic flux paths each of which extends radially between the rotor and stator via the confronting teeth and the tubular member, and axially along both the rotor and the portion of the stator located radially outwardly of the coil. The portion of the tubular member intermediate the teeth thereon is provided with a non-magnetic insert in order to resist the axial passage of magnetic flux therethrough. In one of the claims, the tubular member comprises a portion of a nuclear reactor which is adapted to contain a reactor control rod, the rotor constituting a portion of the drive mechanism for the control rod contained in operation within the tubular member. (author)
Protection device for a thermonuclear device
Kawashima, Shuichi.
1986-01-01
Purpose: To exactly detect the void coefficients of coolants even under high magnetic fields thereby detect the overheat of a thermonuclear device at an early stage. Constitution: The protecting device of this invention comprises a laser beam generation device, a laser beam detection device and an accident detection device. The laser generation device always generates laser beams, which are permeated through coolants and detected by the laser beam detection device, the optical amount of which is transmitted to the accident detection device. The accident detection device judges the excess or insufficiency of the detected optical amount with respect to the optical amount of the laser beams under the stationary state as a reference and issues an accident signal. Since only the optical cables that do not undergo the effect of the magnetic fields are exposed to high magnetic fields in the protection device of this invention, a high reliability can be maintained. (Kamimura, M.)
Linear parallel processing machines I
Von Kunze, M
1984-01-01
As is well-known, non-context-free grammars for generating formal languages happen to be of a certain intrinsic computational power that presents serious difficulties to efficient parsing algorithms as well as for the development of an algebraic theory of contextsensitive languages. In this paper a framework is given for the investigation of the computational power of formal grammars, in order to start a thorough analysis of grammars consisting of derivation rules of the form aB ..-->.. A/sub 1/ ... A /sub n/ b/sub 1/...b /sub m/ . These grammars may be thought of as automata by means of parallel processing, if one considers the variables as operators acting on the terminals while reading them right-to-left. This kind of automata and their 2-dimensional programming language prove to be useful by allowing a concise linear-time algorithm for integer multiplication. Linear parallel processing machines (LP-machines) which are, in their general form, equivalent to Turing machines, include finite automata and pushdown automata (with states encoded) as special cases. Bounded LP-machines yield deterministic accepting automata for nondeterministic contextfree languages, and they define an interesting class of contextsensitive languages. A characterization of this class in terms of generating grammars is established by using derivation trees with crossings as a helpful tool. From the algebraic point of view, deterministic LP-machines are effectively represented semigroups with distinguished subsets. Concerning the dualism between generating and accepting devices of formal languages within the algebraic setting, the concept of accepting automata turns out to reduce essentially to embeddability in an effectively represented extension monoid, even in the classical cases.
Finite-dimensional linear algebra
Gockenbach, Mark S
2010-01-01
Some Problems Posed on Vector SpacesLinear equationsBest approximationDiagonalizationSummaryFields and Vector SpacesFields Vector spaces Subspaces Linear combinations and spanning sets Linear independence Basis and dimension Properties of bases Polynomial interpolation and the Lagrange basis Continuous piecewise polynomial functionsLinear OperatorsLinear operatorsMore properties of linear operatorsIsomorphic vector spaces Linear operator equations Existence and uniqueness of solutions The fundamental theorem; inverse operatorsGaussian elimination Newton's method Linear ordinary differential eq
Linearity and Non-linearity of Photorefractive effect in Materials ...
In this paper we have studied the Linearity and Non-linearity of Photorefractive effect in materials using the band transport model. For low light beam intensities the change in the refractive index is proportional to the electric field for linear optics while for non- linear optics the change in refractive index is directly proportional ...
Linearly Refined Session Types
Pedro Baltazar
2012-11-01
Full Text Available Session types capture precise protocol structure in concurrent programming, but do not specify properties of the exchanged values beyond their basic type. Refinement types are a form of dependent types that can address this limitation, combining types with logical formulae that may refer to program values and can constrain types using arbitrary predicates. We present a pi calculus with assume and assert operations, typed using a session discipline that incorporates refinement formulae written in a fragment of Multiplicative Linear Logic. Our original combination of session and refinement types, together with the well established benefits of linearity, allows very fine-grained specifications of communication protocols in which refinement formulae are treated as logical resources rather than persistent truths.
Kuznetsov, N.; Maz'ya, V.; Vainberg, B.
2002-08-01
This book gives a self-contained and up-to-date account of mathematical results in the linear theory of water waves. The study of waves has many applications, including the prediction of behavior of floating bodies (ships, submarines, tension-leg platforms etc.), the calculation of wave-making resistance in naval architecture, and the description of wave patterns over bottom topography in geophysical hydrodynamics. The first section deals with time-harmonic waves. Three linear boundary value problems serve as the approximate mathematical models for these types of water waves. The next section uses a plethora of mathematical techniques in the investigation of these three problems. The techniques used in the book include integral equations based on Green's functions, various inequalities between the kinetic and potential energy and integral identities which are indispensable for proving the uniqueness theorems. The so-called inverse procedure is applied to constructing examples of non-uniqueness, usually referred to as 'trapped nodes.'
The International Linear Collider
List Benno
2014-04-01
Full Text Available The International Linear Collider (ILC is a proposed e+e− linear collider with a centre-of-mass energy of 200–500 GeV, based on superconducting RF cavities. The ILC would be an ideal machine for precision studies of a light Higgs boson and the top quark, and would have a discovery potential for new particles that is complementary to that of LHC. The clean experimental conditions would allow the operation of detectors with extremely good performance; two such detectors, ILD and SiD, are currently being designed. Both make use of novel concepts for tracking and calorimetry. The Japanese High Energy Physics community has recently recommended to build the ILC in Japan.
The International Linear Collider
List, Benno
2014-04-01
The International Linear Collider (ILC) is a proposed e+e- linear collider with a centre-of-mass energy of 200-500 GeV, based on superconducting RF cavities. The ILC would be an ideal machine for precision studies of a light Higgs boson and the top quark, and would have a discovery potential for new particles that is complementary to that of LHC. The clean experimental conditions would allow the operation of detectors with extremely good performance; two such detectors, ILD and SiD, are currently being designed. Both make use of novel concepts for tracking and calorimetry. The Japanese High Energy Physics community has recently recommended to build the ILC in Japan.
Høskuldsson, Agnar
1996-01-01
Determination of the proper dimension of a given linear model is one of the most important tasks in the applied modeling work. We consider here eight criteria that can be used to determine the dimension of the model, or equivalently, the number of components to use in the model. Four...... the basic problems in determining the dimension of linear models. Then each of the eight measures are treated. The results are illustrated by examples....... of these criteria are widely used ones, while the remaining four are ones derived from the H-principle of mathematical modeling. Many examples from practice show that the criteria derived from the H-principle function better than the known and popular criteria for the number of components. We shall briefly review...
Goldowsky, Michael P. (Inventor)
1987-01-01
A reciprocating linear motor is formed with a pair of ring-shaped permanent magnets having opposite radial polarizations, held axially apart by a nonmagnetic yoke, which serves as an axially displaceable armature assembly. A pair of annularly wound coils having axial lengths which differ from the axial lengths of the permanent magnets are serially coupled together in mutual opposition and positioned with an outer cylindrical core in axial symmetry about the armature assembly. One embodiment includes a second pair of annularly wound coils serially coupled together in mutual opposition and an inner cylindrical core positioned in axial symmetry inside the armature radially opposite to the first pair of coils. Application of a potential difference across a serial connection of the two pairs of coils creates a current flow perpendicular to the magnetic field created by the armature magnets, thereby causing limited linear displacement of the magnets relative to the coils.
Henneaux, Marc; Teitelboim, Claudio
2005-01-01
We show that duality transformations of linearized gravity in four dimensions, i.e., rotations of the linearized Riemann tensor and its dual into each other, can be extended to the dynamical fields of the theory so as to be symmetries of the action and not just symmetries of the equations of motion. Our approach relies on the introduction of two superpotentials, one for the spatial components of the spin-2 field and the other for their canonically conjugate momenta. These superpotentials are two-index, symmetric tensors. They can be taken to be the basic dynamical fields and appear locally in the action. They are simply rotated into each other under duality. In terms of the superpotentials, the canonical generator of duality rotations is found to have a Chern-Simons-like structure, as in the Maxwell case
Phinney, N.
1992-01-01
The SLAC Linear Collider has begun a new era of operation with the SLD detector. During 1991 there was a first engineering run for the SLD in parallel with machine improvements to increase luminosity and reliability. For the 1992 run, a polarized electron source was added and more than 10,000 Zs with an average of 23% polarization have been logged by the SLD. This paper discusses the performance of the SLC in 1991 and 1992 and the technical advances that have produced higher luminosity. Emphasis will be placed on issues relevant to future linear colliders such as producing and maintaining high current, low emittance beams and focusing the beams to the micron scale for collisions. (Author) tab., 2 figs., 18 refs
Linear waves and instabilities
Bers, A.
1975-01-01
The electrodynamic equations for small-amplitude waves and their dispersion relation in a homogeneous plasma are outlined. For such waves, energy and momentum, and their flow and transformation, are described. Perturbation theory of waves is treated and applied to linear coupling of waves, and the resulting instabilities from such interactions between active and passive waves. Linear stability analysis in time and space is described where the time-asymptotic, time-space Green's function for an arbitrary dispersion relation is developed. The perturbation theory of waves is applied to nonlinear coupling, with particular emphasis on pump-driven interactions of waves. Details of the time--space evolution of instabilities due to coupling are given. (U.S.)
Extended linear chain compounds
Linear chain substances span a large cross section of contemporary chemistry ranging from covalent polymers, to organic charge transfer com plexes to nonstoichiometric transition metal coordination complexes. Their commonality, which coalesced intense interest in the theoretical and exper imental solid state physics/chemistry communities, was based on the obser vation that these inorganic and organic polymeric substrates exhibit striking metal-like electrical and optical properties. Exploitation and extension of these systems has led to the systematic study of both the chemistry and physics of highly and poorly conducting linear chain substances. To gain a salient understanding of these complex materials rich in anomalous aniso tropic electrical, optical, magnetic, and mechanical properties, the conver gence of diverse skills and talents was required. The constructive blending of traditionally segregated disciplines such as synthetic and physical organic, inorganic, and polymer chemistry, crystallog...
Diamond, Jared M.
1966-01-01
1. The relation between osmotic gradient and rate of osmotic water flow has been measured in rabbit gall-bladder by a gravimetric procedure and by a rapid method based on streaming potentials. Streaming potentials were directly proportional to gravimetrically measured water fluxes. 2. As in many other tissues, water flow was found to vary with gradient in a markedly non-linear fashion. There was no consistent relation between the water permeability and either the direction or the rate of water flow. 3. Water flow in response to a given gradient decreased at higher osmolarities. The resistance to water flow increased linearly with osmolarity over the range 186-825 m-osM. 4. The resistance to water flow was the same when the gall-bladder separated any two bathing solutions with the same average osmolarity, regardless of the magnitude of the gradient. In other words, the rate of water flow is given by the expression (Om — Os)/[Ro′ + ½k′ (Om + Os)], where Ro′ and k′ are constants and Om and Os are the bathing solution osmolarities. 5. Of the theories advanced to explain non-linear osmosis in other tissues, flow-induced membrane deformations, unstirred layers, asymmetrical series-membrane effects, and non-osmotic effects of solutes could not explain the results. However, experimental measurements of water permeability as a function of osmolarity permitted quantitative reconstruction of the observed water flow—osmotic gradient curves. Hence non-linear osmosis in rabbit gall-bladder is due to a decrease in water permeability with increasing osmolarity. 6. The results suggest that aqueous channels in the cell membrane behave as osmometers, shrinking in concentrated solutions of impermeant molecules and thereby increasing membrane resistance to water flow. A mathematical formulation of such a membrane structure is offered. PMID:5945254
Fundamentals of linear algebra
Dash, Rajani Ballav
2008-01-01
FUNDAMENTALS OF LINEAR ALGEBRA is a comprehensive Text Book, which can be used by students and teachers of All Indian Universities. The Text has easy, understandable form and covers all topics of UGC Curriculum. There are lots of worked out examples which helps the students in solving the problems without anybody's help. The Problem sets have been designed keeping in view of the questions asked in different examinations.
Sander, K F
1964-01-01
Linear Network Theory covers the significant algebraic aspect of network theory, with minimal reference to practical circuits. The book begins the presentation of network analysis with the exposition of networks containing resistances only, and follows it up with a discussion of networks involving inductance and capacity by way of the differential equations. Classification and description of certain networks, equivalent networks, filter circuits, and network functions are also covered. Electrical engineers, technicians, electronics engineers, electricians, and students learning the intricacies
Non linear viscoelastic models
Agerkvist, Finn T.
2011-01-01
Viscoelastic eects are often present in loudspeaker suspensions, this can be seen in the displacement transfer function which often shows a frequency dependent value below the resonance frequency. In this paper nonlinear versions of the standard linear solid model (SLS) are investigated....... The simulations show that the nonlinear version of the Maxwell SLS model can result in a time dependent small signal stiness while the Kelvin Voight version does not....
Relativistic Linear Restoring Force
Clark, D.; Franklin, J.; Mann, N.
2012-01-01
We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…
Superconducting linear colliders
Anon.
1990-01-01
The advantages of superconducting radiofrequency (SRF) for particle accelerators have been demonstrated by successful operation of systems in the TRISTAN and LEP electron-positron collider rings respectively at the Japanese KEK Laboratory and at CERN. If performance continues to improve and costs can be lowered, this would open an attractive option for a high luminosity TeV (1000 GeV) linear collider
Perturbed asymptotically linear problems
Bartolo, R.; Candela, A. M.; Salvatore, A.
2012-01-01
The aim of this paper is investigating the existence of solutions of some semilinear elliptic problems on open bounded domains when the nonlinearity is subcritical and asymptotically linear at infinity and there is a perturbation term which is just continuous. Also in the case when the problem has not a variational structure, suitable procedures and estimates allow us to prove that the number of distinct crtitical levels of the functional associated to the unperturbed problem is "stable" unde...
Miniature linear cooler development
Pruitt, G.R.
1993-01-01
An overview is presented of the status of a family of miniature linear coolers currently under development by Hughes Aircraft Co. for use in hand held, volume limited or power limited infrared applications. These coolers, representing the latest additions to the Hughes family of TOP trademark [twin-opposed piston] linear coolers, have been fabricated and tested in three different configurations. Each configuration is designed to utilize a common compressor assembly resulting in reduced manufacturing costs. The baseline compressor has been integrated with two different expander configurations and has been operated with two different levels of input power. These various configuration combinations offer a wide range of performance and interface characteristics which may be tailored to applications requiring limited power and size without significantly compromising cooler capacity or cooldown characteristics. Key cooler characteristics and test data are summarized for three combinations of cooler configurations which are representative of the versatility of this linear cooler design. Configurations reviewed include the shortened coldfinger [1.50 to 1.75 inches long], limited input power [less than 17 Watts] for low power availability applications; the shortened coldfinger with higher input power for lightweight, higher performance applications; and coldfingers compatible with DoD 0.4 Watt Common Module coolers for wider range retrofit capability. Typical weight of these miniature linear coolers is less than 500 grams for the compressor, expander and interconnecting transfer line. Cooling capacity at 80K at room ambient conditions ranges from 400 mW to greater than 550 mW. Steady state power requirements for maintaining a heat load of 150 mW at 80K has been shown to be less than 8 Watts. Ongoing reliability growth testing is summarized including a review of the latest test article results
Avram Mihai
2017-01-01
Full Text Available The paper presents a linear pneumatic actuator with short working stroke. It consists of a pneumatic motor (a simple stroke cylinder or a membrane chamber, two 2/2 pneumatic distributors “all or nothing” electrically commanded for controlling the intake/outtake flow to/from the active chamber of the motor, a position transducer and a microcontroller. There is also presented the theoretical analysis (mathematical modelling and numerical simulation accomplished.
Avram Mihai; Niţu Constantin; Bucşan Constantin; Grămescu Bogdan
2017-01-01
The paper presents a linear pneumatic actuator with short working stroke. It consists of a pneumatic motor (a simple stroke cylinder or a membrane chamber), two 2/2 pneumatic distributors “all or nothing” electrically commanded for controlling the intake/outtake flow to/from the active chamber of the motor, a position transducer and a microcontroller. There is also presented the theoretical analysis (mathematical modelling and numerical simulation) accomplished.
Scheffel, J.
1984-03-01
The linear Grad-Shafranov equation for a toroidal, axisymmetric plasma is solved analytically. Exact solutions are given in terms of confluent hyper-geometric functions. As an alternative, simple and accurate WKBJ solutions are presented. With parabolic pressure profiles, both hollow and peaked toroidal current density profiles are obtained. As an example the equilibrium of a z-pinch with a square-shaped cross section is derived.(author)
Buttram, M.T.; Ginn, J.W.
1988-06-21
A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.
Springer, T A
1998-01-01
"[The first] ten chapters...are an efficient, accessible, and self-contained introduction to affine algebraic groups over an algebraically closed field. The author includes exercises and the book is certainly usable by graduate students as a text or for self-study...the author [has a] student-friendly style… [The following] seven chapters... would also be a good introduction to rationality issues for algebraic groups. A number of results from the literature…appear for the first time in a text." –Mathematical Reviews (Review of the Second Edition) "This book is a completely new version of the first edition. The aim of the old book was to present the theory of linear algebraic groups over an algebraically closed field. Reading that book, many people entered the research field of linear algebraic groups. The present book has a wider scope. Its aim is to treat the theory of linear algebraic groups over arbitrary fields. Again, the author keeps the treatment of prerequisites self-contained. The material of t...
Parametric Linear Dynamic Logic
Peter Faymonville
2014-08-01
Full Text Available We introduce Parametric Linear Dynamic Logic (PLDL, which extends Linear Dynamic Logic (LDL by temporal operators equipped with parameters that bound their scope. LDL was proposed as an extension of Linear Temporal Logic (LTL that is able to express all ω-regular specifications while still maintaining many of LTL's desirable properties like an intuitive syntax and a translation into non-deterministic Büchi automata of exponential size. But LDL lacks capabilities to express timing constraints. By adding parameterized operators to LDL, we obtain a logic that is able to express all ω-regular properties and that subsumes parameterized extensions of LTL like Parametric LTL and PROMPT-LTL. Our main technical contribution is a translation of PLDL formulas into non-deterministic Büchi word automata of exponential size via alternating automata. This yields a PSPACE model checking algorithm and a realizability algorithm with doubly-exponential running time. Furthermore, we give tight upper and lower bounds on optimal parameter values for both problems. These results show that PLDL model checking and realizability are not harder than LTL model checking and realizability.
Quantum linear Boltzmann equation
Vacchini, Bassano; Hornberger, Klaus
2009-01-01
We review the quantum version of the linear Boltzmann equation, which describes in a non-perturbative fashion, by means of scattering theory, how the quantum motion of a single test particle is affected by collisions with an ideal background gas. A heuristic derivation of this Lindblad master equation is presented, based on the requirement of translation-covariance and on the relation to the classical linear Boltzmann equation. After analyzing its general symmetry properties and the associated relaxation dynamics, we discuss a quantum Monte Carlo method for its numerical solution. We then review important limiting forms of the quantum linear Boltzmann equation, such as the case of quantum Brownian motion and pure collisional decoherence, as well as the application to matter wave optics. Finally, we point to the incorporation of quantum degeneracies and self-interactions in the gas by relating the equation to the dynamic structure factor of the ambient medium, and we provide an extension of the equation to include internal degrees of freedom.
Emma, P.
1995-01-01
The Stanford Linear Collider (SLC) is the first and only high-energy e + e - linear collider in the world. Its most remarkable features are high intensity, submicron sized, polarized (e - ) beams at a single interaction point. The main challenges posed by these unique characteristics include machine-wide emittance preservation, consistent high intensity operation, polarized electron production and transport, and the achievement of a high degree of beam stability on all time scales. In addition to serving as an important machine for the study of Z 0 boson production and decay using polarized beams, the SLC is also an indispensable source of hands-on experience for future linear colliders. Each new year of operation has been highlighted with a marked improvement in performance. The most significant improvements for the 1994-95 run include new low impedance vacuum chambers for the damping rings, an upgrade to the optics and diagnostics of the final focus systems, and a higher degree of polarization from the electron source. As a result, the average luminosity has nearly doubled over the previous year with peaks approaching 10 30 cm -2 s -1 and an 80% electron polarization at the interaction point. These developments as well as the remaining identifiable performance limitations will be discussed
A linear atomic quantum coupler
El-Orany, Faisal A A [Department of Mathematics and computer Science, Faculty of Science, Suez Canal University 41522, Ismailia (Egypt); Wahiddin, M R B, E-mail: el_orany@hotmail.co, E-mail: faisal.orany@mimos.m, E-mail: mridza@mimos.m [Cyberspace Security Laboratory, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur (Malaysia)
2010-04-28
In this paper we develop the notion of the linear atomic quantum coupler. This device consists of two modes propagating into two waveguides, each of which includes a localized atom. These waveguides are placed close enough to allow exchange of energy between them via evanescent waves. Each mode interacts with the atom in the same waveguide in the standard way as the Jaynes-Cummings model (JCM) and with the atom-mode system in the second waveguide via the evanescent wave. We present the Hamiltonian for this system and deduce its wavefunction. We investigate the atomic inversions and the second-order correlation function. In contrast to the conventional coupler the atomic quantum coupler is able to generate nonclassical effects. The atomic inversions can exhibit a long revival-collapse phenomenon as well as subsidiary revivals based on the competition among the switching mechanisms in the system. Finally, under certain conditions the system can yield the results of the two-mode JCM.
Garbet, X.; Mourgues, F.; Samain, A.
1987-01-01
Among the various instabilities which could explain the anomalous electron heat transport observed in tokamaks during additional heating, a microtearing turbulence is a reasonable candidate since it affects directly the magnetic topology. This turbulence may be described in a proper frame rotating around the majors axis by a static potential vector. In strong non linear regimes, the flow of electrons along the stochastic field lines induces a current. The point is to know whether this current can sustain the turbulence. The mechanisms of this self-consistency, involving the combined effects of the thermal diamagnetism and of the electric drift are presented here
Wangler, Thomas P
2008-01-01
Thomas P. Wangler received his B.S. degree in physics from Michigan State University, and his Ph.D. degree in physics and astronomy from the University of Wisconsin. After postdoctoral appointments at the University of Wisconsin and Brookhaven National Laboratory, he joined the staff of Argonne National Laboratory in 1966, working in the fields of experimental high-energy physics and accelerator physics. He joined the Accelerator Technology Division at Los Alamos National Laboratory in 1979, where he specialized in high-current beam physics and linear accelerator design and technology. In 2007
Richter, B.; Bell, R.A.; Brown, K.L.
1980-06-01
The SLAC LINEAR COLLIDER is designed to achieve an energy of 100 GeV in the electron-positron center-of-mass system by accelerating intense bunches of particles in the SLAC linac and transporting the electron and positron bunches in a special magnet system to a point where they are focused to a radius of about 2 microns and made to collide head on. The rationale for this new type of colliding beam system is discussed, the project is described, some of the novel accelerator physics issues involved are discussed, and some of the critical technical components are described
Lopez, Cesar
2014-01-01
MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. MATLAB Linear Algebra introduces you to the MATLAB language with practical hands-on instructions and results, allowing you to quickly achieve your goals. In addition to giving an introduction to
Control Strategies for Arrays of Wave Energy Devices
Westphalen, J; Bacelli, G; Balitsky, P; Ringwood, John
2011-01-01
In this paper, we investigate the differences between two control strategies for a two-device linear array of wave energy converters (WEC) for device spacings of 4 to 80 times the device diameter. The WECs operate in heave only and are controlled in real time. The control strategies, called the independent device and global array control, estimate the excitation forces and calculate the optimum vertical velocity trajectory and reactive power take off force to achieve the ...
Special set linear algebra and special set fuzzy linear algebra
Kandasamy, W. B. Vasantha; Smarandache, Florentin; Ilanthenral, K.
2009-01-01
The authors in this book introduce the notion of special set linear algebra and special set fuzzy Linear algebra, which is an extension of the notion set linear algebra and set fuzzy linear algebra. These concepts are best suited in the application of multi expert models and cryptology. This book has five chapters. In chapter one the basic concepts about set linear algebra is given in order to make this book a self contained one. The notion of special set linear algebra and their fuzzy analog...
Munehiro, H
1980-05-29
When driving the carriage of a printer through a rotating motor, there are problems regarding the limited accuracy of the carriage position due to rotation or contraction and ageing of the cable. In order to solve the problem, a direct drive system was proposed, in which the printer carriage is driven by a linear motor. If one wants to keep the motor circuit of such a motor compact, then the magnetic flux density in the air gap must be reduced or the motor travel must be reduced. It is the purpose of this invention to create an electrodynamic linear motor, which on the one hand is compact and light and on the other hand has a relatively high constant force over a large travel. The invention is characterised by the fact that magnetic fields of alternating polarity are generated at equal intervals in the magnetic field, and that the coil arrangement has 2 adjacent coils, whose size corresponds to half the length of each magnetic pole. A logic circuit is provided to select one of the two coils and to determine the direction of the current depending on the signals of a magnetic field sensor on the coil arrangement.
Kozarov, A.; Petrov, O.; Antonov, J.; Sotirova, S.; Petrova, B.
2006-01-01
The purpose of the linear wind-power generator described in this article is to decrease the following disadvantages of the common wind-powered turbine: 1) large bending and twisting moments to the blades and the shaft, especially when strong winds and turbulence exist; 2) significant values of the natural oscillation period of the construction result in the possibility of occurrence of destroying resonance oscillations; 3) high velocity of the peripheral parts of the rotor creating a danger for birds; 4) difficulties, connected with the installation and the operation on the mountain ridges and passages where the wind energy potential is the largest. The working surfaces of the generator in questions driven by the wind are not connected with a joint shaft but each moves along a railway track with few oscillations. So the sizes of each component are small and their number can be rather large. The mechanical trajectory is not a circle but a closed outline in a vertical plain, which consists of two rectilinear sectors, one above the other, connected in their ends by semi-circumferences. The mechanical energy of each component turns into electrical on the principle of the linear electrical generator. A regulation is provided when the direction of the wind is perpendicular to the route. A possibility of effectiveness is shown through aiming of additional quantities of air to the movable components by static barriers
Electrically Driven Photonic Crystal Nanocavity Devices
2012-01-01
material, here gallium arsenide and indium arsenide self- assembled quantum dots (QDs). QDs are preferred for the gain medium because they can have...blue points ) and 150 K (green points ). The black lines are linear fits to the above threshold output power of the lasers, which are used to find the...SHAMBAT et al.: ELECTRICALLY DRIVEN PHOTONIC CRYSTAL NANOCAVITY DEVICES 1707 Fig. 13. (a) Tilted SEM picture of a fabricated triple cavity device. The in
rf coaxial couplers for high-intensity linear accelerators
Manca, J.J.; Knapp, E.A.
1980-02-01
Two rf coaxial couplers that are particularly suitable for intertank connection of the disk-and-washer accelerating structure for use in high-intensity linear accelerators have been developed. These devices have very high coupling to the accelerating structure and very low rf power loss at the operating frequency, and they can be designed for any relative particle velocity β > 0.4. Focusing and monitoring devices can be located inside these couplers
Linearization of the Lorenz system
Li, Chunbiao; Sprott, Julien Clinton; Thio, Wesley
2015-01-01
A partial and complete piecewise linearized version of the Lorenz system is proposed. The linearized versions have an independent total amplitude control parameter. Additional further linearization leads naturally to a piecewise linear version of the diffusionless Lorenz system. A chaotic circuit with a single amplitude controller is then implemented using a new switch element, producing a chaotic oscillation that agrees with the numerical calculation for the piecewise linear diffusionless Lorenz system. - Highlights: • A partial and complete piecewise linearized version of the Lorenz system are addressed. • The linearized versions have an independent total amplitude control parameter. • A piecewise linear version of the diffusionless Lorenz system is derived by further linearization. • A corresponding chaotic circuit without any multiplier is implemented for the chaotic oscillation
Topics in computational linear optimization
Hultberg, Tim Helge
2000-01-01
Linear optimization has been an active area of research ever since the pioneering work of G. Dantzig more than 50 years ago. This research has produced a long sequence of practical as well as theoretical improvements of the solution techniques avilable for solving linear optimization problems...... of high quality solvers and the use of algebraic modelling systems to handle the communication between the modeller and the solver. This dissertation features four topics in computational linear optimization: A) automatic reformulation of mixed 0/1 linear programs, B) direct solution of sparse unsymmetric...... systems of linear equations, C) reduction of linear programs and D) integration of algebraic modelling of linear optimization problems in C++. Each of these topics is treated in a separate paper included in this dissertation. The efficiency of solving mixed 0-1 linear programs by linear programming based...
Linearization of the Lorenz system
Li, Chunbiao, E-mail: goontry@126.com [School of Electronic & Information Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Engineering Technology Research and Development Center of Jiangsu Circulation Modernization Sensor Network, Jiangsu Institute of Commerce, Nanjing 211168 (China); Sprott, Julien Clinton [Department of Physics, University of Wisconsin–Madison, Madison, WI 53706 (United States); Thio, Wesley [Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH 43210 (United States)
2015-05-08
A partial and complete piecewise linearized version of the Lorenz system is proposed. The linearized versions have an independent total amplitude control parameter. Additional further linearization leads naturally to a piecewise linear version of the diffusionless Lorenz system. A chaotic circuit with a single amplitude controller is then implemented using a new switch element, producing a chaotic oscillation that agrees with the numerical calculation for the piecewise linear diffusionless Lorenz system. - Highlights: • A partial and complete piecewise linearized version of the Lorenz system are addressed. • The linearized versions have an independent total amplitude control parameter. • A piecewise linear version of the diffusionless Lorenz system is derived by further linearization. • A corresponding chaotic circuit without any multiplier is implemented for the chaotic oscillation.
On the linear programming bound for linear Lee codes.
Astola, Helena; Tabus, Ioan
2016-01-01
Based on an invariance-type property of the Lee-compositions of a linear Lee code, additional equality constraints can be introduced to the linear programming problem of linear Lee codes. In this paper, we formulate this property in terms of an action of the multiplicative group of the field [Formula: see text] on the set of Lee-compositions. We show some useful properties of certain sums of Lee-numbers, which are the eigenvalues of the Lee association scheme, appearing in the linear programming problem of linear Lee codes. Using the additional equality constraints, we formulate the linear programming problem of linear Lee codes in a very compact form, leading to a fast execution, which allows to efficiently compute the bounds for large parameter values of the linear codes.
Flavour tagging at the future linear collider
Hansen, S.X.
2003-01-01
High performance flavour tagging of jets containing heavy flavours is crucial for the studies planned for the future high energy e + e - Linear Collider (LC). Pixel detectors have proven to provide very powerful flavour identification, for this reason the Linear Collider Flavour Identification collaboration has decided to concentrate its R and D work for the future LC on a Charged Coupled Device pixel vertex detector, and study the flavour tagging performance of the design to optimize it. In this work we first evaluate the basic tracking performance. We then estimate the flavour tagging performance of the present detector layout, using a neural network approach. We conclude by studying the energy dependence of the performance
Linear magnetic fusion: summary of Seattle workshop
1977-12-01
The linear-geometry magnetic confinement concept is among the oldest used in the study of high-temperature plasmas. However, it has generally been discounted as a suitable approach for demonstrating controlled thermonuclear fusion because rapid losses from the plasma column ends necessitate very long devices. Further, the losses and how to overcome them have not yet received parametric experimental study, nor do facilities exist with which such definitive experiments could be performed. Nonetheless, the important positive attribute, simplicity, together with the appearance of several ideas for reducing end losses have provided motivation for continued research on linear magnetic fusion (LMF). These motivations led to the LMF workshop, held in Seattle, March 9--11, 1977, which explored the potential of LMF as an alternate approach to fusion. A broad range of LMF aspects were addressed, including radial and axial losses, stability and equilibrium, heating, technology, and reactor considerations. The conclusions drawn at the workshop are summarized
Radiation load of workers on linear accelerators
Kralik, G.; Kantova, Z.; Fribertova, M.; Kontrisova, K.
2014-01-01
Burden of health care personnel working on linear accelerators. New examination and treatment methods enable to reduce the number of health care personnel even in the case of increased numbers of examined patients. However, still open is the question of determining the effective dose delivered to health care personnel. The employment of several methods of evaluation of received dose at one workplace makes it possible to compare the accuracy and reliability of the respective types of measuring devices, as well as to point out the pitfalls of their use.At the St. Elizabeth Cancer Institute we compared the results of measurements of TL dosimeters, and OSL dosimeters at workplaces with linear accelerators. (authors)
A medical device is any product used to diagnose, cure, or treat a condition, or to prevent disease. They ... may need one in a hospital. To use medical devices safely Know how your device works. Keep ...
Parallel algorithms for numerical linear algebra
van der Vorst, H
1990-01-01
This is the first in a new series of books presenting research results and developments concerning the theory and applications of parallel computers, including vector, pipeline, array, fifth/future generation computers, and neural computers.All aspects of high-speed computing fall within the scope of the series, e.g. algorithm design, applications, software engineering, networking, taxonomy, models and architectural trends, performance, peripheral devices.Papers in Volume One cover the main streams of parallel linear algebra: systolic array algorithms, message-passing systems, algorithms for p
MEMS linear and nonlinear statics and dynamics
Younis, Mohammad I
2011-01-01
MEMS Linear and Nonlinear Statics and Dynamics presents the necessary analytical and computational tools for MEMS designers to model and simulate most known MEMS devices, structures, and phenomena. This book also provides an in-depth analysis and treatment of the most common static and dynamic phenomena in MEMS that are encountered by engineers. Coverage also includes nonlinear modeling approaches to modeling various MEMS phenomena of a nonlinear nature, such as those due to electrostatic forces, squeeze-film damping, and large deflection of structures. The book also: Includes examples of nume
Dose Rate Effects in Linear Bipolar Transistors
Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis
2011-01-01
Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.
Square pulse linear transformer driver
A. A. Kim
2012-04-01
Full Text Available The linear transformer driver (LTD technological approach can result in relatively compact devices that can deliver fast, high current, and high-voltage pulses straight out of the LTD cavity without any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The usual LTD architecture [A. A. Kim, M. G. Mazarakis, V. A. Sinebryukhov, B. M. Kovalchuk, V. A. Vizir, S. N Volkov, F. Bayol, A. N. Bastrikov, V. G. Durakov, S. V. Frolov, V. M. Alexeenko, D. H. McDaniel, W. E. Fowler, K. LeCheen, C. Olson, W. A. Stygar, K. W. Struve, J. Porter, and R. M. Gilgenbach, Phys. Rev. ST Accel. Beams 12, 050402 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050402; M. G. Mazarakis, W. E. Fowler, A. A. Kim, V. A. Sinebryukhov, S. T. Rogowski, R. A. Sharpe, D. H. McDaniel, C. L. Olson, J. L. Porter, K. W. Struve, W. A. Stygar, and J. R. Woodworth, Phys. Rev. ST Accel. Beams 12, 050401 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050401] provides sine shaped output pulses that may not be well suited for some applications like z-pinch drivers, flash radiography, high power microwaves, etc. A more suitable power pulse would have a flat or trapezoidal (rising or falling top. In this paper, we present the design and first test results of an LTD cavity that generates such a type of output pulse by including within its circular array a number of third harmonic bricks in addition to the main bricks. A voltage adder made out of a square pulse cavity linear array will produce the same shape output pulses provided that the timing of each cavity is synchronized with the propagation of the electromagnetic pulse.
Introduction to linear elasticity
Gould, Phillip L
2013-01-01
Introduction to Linear Elasticity, 3rd Edition, provides an applications-oriented grounding in the tensor-based theory of elasticity for students in mechanical, civil, aeronautical, and biomedical engineering, as well as materials and earth science. The book is distinct from the traditional text aimed at graduate students in solid mechanics by introducing the subject at a level appropriate for advanced undergraduate and beginning graduate students. The author's presentation allows students to apply the basic notions of stress analysis and move on to advanced work in continuum mechanics, plasticity, plate and shell theory, composite materials, viscoelasticity and finite method analysis. This book also: Emphasizes tensor-based approach while still distilling down to explicit notation Provides introduction to theory of plates, theory of shells, wave propagation, viscoelasticity and plasticity accessible to advanced undergraduate students Appropriate for courses following emerging trend of teaching solid mechan...
Haniger, L.; Elger, R.; Kocandrle, L.; Zdebor, J.
1986-01-01
A linear step drive is described developed in Czechoslovak-Soviet cooperation and intended for driving WWER-1000 control rods. The functional principle is explained of the motor and the mechanical and electrical parts of the drive, power control, and the indicator of position are described. The motor has latches situated in the reactor at a distance of 3 m from magnetic armatures, it has a low structural height above the reactor cover, which suggests its suitability for seismic localities. Its magnetic circuits use counterpoles; the mechanical shocks at the completion of each step are damped using special design features. The position indicator is of a special design and evaluates motor position within ±1% of total travel. A drive diagram and the flow chart of both the control electronics and the position indicator are presented. (author) 4 figs
1976-01-01
This report covers the activity of the Linear Accelerator Laboratory during the period June 1974-June 1976. The activity of the Laboratory is essentially centered on high energy physics. The main activities were: experiments performed with the colliding rings (ACO), construction of the new colliding rings and beginning of the work at higher energy (DCI), bubble chamber experiments with the CERN PS neutrino beam, counter experiments with CERN's PS and setting-up of equipment for new experiments with CERN's SPS. During this period a project has also been prepared for an experiment with the new PETRA colliding ring at Hamburg. On the other hand, intense collaboration with the LURE Laboratory, using the electron synchrotron radiation emitted by ACO and DCI, has been developed [fr
Van Atta, C.M.; Beringer, R.; Smith, L.
1959-01-01
A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.
Tip, A.
1998-06-01
Starting from Maxwell's equations for a linear, nonconducting, absorptive, and dispersive medium, characterized by the constitutive equations D(x,t)=ɛ1(x)E(x,t)+∫t-∞dsχ(x,t-s)E(x,s) and H(x,t)=B(x,t), a unitary time evolution and canonical formalism is obtained. Given the complex, coordinate, and frequency-dependent, electric permeability ɛ(x,ω), no further assumptions are made. The procedure leads to a proper definition of band gaps in the periodic case and a new continuity equation for energy flow. An S-matrix formalism for scattering from lossy objects is presented in full detail. A quantized version of the formalism is derived and applied to the generation of Čerenkov and transition radiation as well as atomic decay. The last case suggests a useful generalization of the density of states to the absorptive situation.
Implantable electronic medical devices
Fitzpatrick, Dennis
2014-01-01
Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t
Computer Program For Linear Algebra
Krogh, F. T.; Hanson, R. J.
1987-01-01
Collection of routines provided for basic vector operations. Basic Linear Algebra Subprogram (BLAS) library is collection from FORTRAN-callable routines for employing standard techniques to perform basic operations of numerical linear algebra.
Quaternion Linear Canonical Transform Application
Bahri, Mawardi
2015-01-01
Quaternion linear canonical transform (QLCT) is a generalization of the classical linear canonical transfom (LCT) using quaternion algebra. The focus of this paper is to introduce an application of the QLCT to study of generalized swept-frequency filter
Recursive Algorithm For Linear Regression
Varanasi, S. V.
1988-01-01
Order of model determined easily. Linear-regression algorithhm includes recursive equations for coefficients of model of increased order. Algorithm eliminates duplicative calculations, facilitates search for minimum order of linear-regression model fitting set of data satisfactory.
Dynamical systems and linear algebra
Colonius, Fritz (Prof.)
2007-01-01
Dynamical systems and linear algebra / F. Colonius, W. Kliemann. - In: Handbook of linear algebra / ed. by Leslie Hogben. - Boca Raton : Chapman & Hall/CRC, 2007. - S. 56,1-56,22. - (Discrete mathematics and its applications)
Linear spaces: history and theory
Albrecht Beutelspracher
1990-01-01
Linear spaces belong to the most fundamental geometric and combinatorial structures. In this paper I would like to give an onerview about the theory of embedding finite linear spaces in finite projective planes.
Linear versus non-linear supersymmetry, in general
Ferrara, Sergio [Theoretical Physics Department, CERN,CH-1211 Geneva 23 (Switzerland); INFN - Laboratori Nazionali di Frascati,Via Enrico Fermi 40, I-00044 Frascati (Italy); Department of Physics and Astronomy, UniversityC.L.A.,Los Angeles, CA 90095-1547 (United States); Kallosh, Renata [SITP and Department of Physics, Stanford University,Stanford, California 94305 (United States); Proeyen, Antoine Van [Institute for Theoretical Physics, Katholieke Universiteit Leuven,Celestijnenlaan 200D, B-3001 Leuven (Belgium); Wrase, Timm [Institute for Theoretical Physics, Technische Universität Wien,Wiedner Hauptstr. 8-10, A-1040 Vienna (Austria)
2016-04-12
We study superconformal and supergravity models with constrained superfields. The underlying version of such models with all unconstrained superfields and linearly realized supersymmetry is presented here, in addition to the physical multiplets there are Lagrange multiplier (LM) superfields. Once the equations of motion for the LM superfields are solved, some of the physical superfields become constrained. The linear supersymmetry of the original models becomes non-linearly realized, its exact form can be deduced from the original linear supersymmetry. Known examples of constrained superfields are shown to require the following LM’s: chiral superfields, linear superfields, general complex superfields, some of them are multiplets with a spin.
Linear versus non-linear supersymmetry, in general
Ferrara, Sergio; Kallosh, Renata; Proeyen, Antoine Van; Wrase, Timm
2016-01-01
We study superconformal and supergravity models with constrained superfields. The underlying version of such models with all unconstrained superfields and linearly realized supersymmetry is presented here, in addition to the physical multiplets there are Lagrange multiplier (LM) superfields. Once the equations of motion for the LM superfields are solved, some of the physical superfields become constrained. The linear supersymmetry of the original models becomes non-linearly realized, its exact form can be deduced from the original linear supersymmetry. Known examples of constrained superfields are shown to require the following LM’s: chiral superfields, linear superfields, general complex superfields, some of them are multiplets with a spin.
Monahan, John F
2008-01-01
Preface Examples of the General Linear Model Introduction One-Sample Problem Simple Linear Regression Multiple Regression One-Way ANOVA First Discussion The Two-Way Nested Model Two-Way Crossed Model Analysis of Covariance Autoregression Discussion The Linear Least Squares Problem The Normal Equations The Geometry of Least Squares Reparameterization Gram-Schmidt Orthonormalization Estimability and Least Squares Estimators Assumptions for the Linear Mean Model Confounding, Identifiability, and Estimability Estimability and Least Squares Estimators F
Templates for Linear Algebra Problems
Bai, Z.; Day, D.; Demmel, J.; Dongarra, J.; Gu, M.; Ruhe, A.; Vorst, H.A. van der
1995-01-01
The increasing availability of advanced-architecture computers is having a very signicant eect on all spheres of scientic computation, including algorithm research and software development in numerical linear algebra. Linear algebra {in particular, the solution of linear systems of equations and
Linearization of CIF through SOS
Nadales Agut, D.E.; Reniers, M.A.; Luttik, B.; Valencia, F.
2011-01-01
Linearization is the procedure of rewriting a process term into a linear form, which consist only of basic operators of the process language. This procedure is interesting both from a theoretical and a practical point of view. In particular, a linearization algorithm is needed for the Compositional
Engberg, Uffe Henrik; Winskel, Glynn
This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some apprai...
Linear local stability of electrostatic drift modes in helical systems
Yamagishi, O.; Nakajima, N.; Sugama, H.; Nakamura, Y.
2003-01-01
We investigate the stability of the drift wave in helical systems. For this purpose, we solve the linear local gyrokinetic-Poisson equation, in the electrostatic regime. As a model of helical plasmas, Large helical Device (LHD) is considered. The equation we apply is rather exact in the framework of linear gyrokinetic theory, where only the approximation is the ballooning representation. In this paper, we consider only collisionless cases. All the frequency regime can be naturally reated without any assumptions, and in such cases, ion temperature gradient modes (ITG), trapped electron modes (TEM), and electron temperature gradient modes (ETG) are expected to become unstable linearly independently. (orig.)
Richards, J.A.
1977-01-01
A linear particle accelerator which provides a pulsed beam of charged particles of uniform energy is described. The accelerator is in the form of an evacuated dielectric tube, inside of which a particle source is located at one end of the tube, with a target or window located at the other end of the dielectric tube. Along the length of the tube are externally located pairs of metal plates, each insulated from each other in an insulated housing. Each of the plates of a pair are connected to an electrical source of voltage of opposed polarity, with the polarity of the voltage of the plates oriented so that the plate of a pair, nearer to the particle source, is of the opposed polarity to the charge of the particle emitted by the source. Thus, a first plate about the tube located nearest the particle source, attracts a particle which as it passes through the tube past the first plate is then repelled by the reverse polarity of the second plate of the pair to continue moving towards the target
Generalized Linear Covariance Analysis
Carpenter, James R.; Markley, F. Landis
2014-01-01
This talk presents a comprehensive approach to filter modeling for generalized covariance analysis of both batch least-squares and sequential estimators. We review and extend in two directions the results of prior work that allowed for partitioning of the state space into solve-for'' and consider'' parameters, accounted for differences between the formal values and the true values of the measurement noise, process noise, and textita priori solve-for and consider covariances, and explicitly partitioned the errors into subspaces containing only the influence of the measurement noise, process noise, and solve-for and consider covariances. In this work, we explicitly add sensitivity analysis to this prior work, and relax an implicit assumption that the batch estimator's epoch time occurs prior to the definitive span. We also apply the method to an integrated orbit and attitude problem, in which gyro and accelerometer errors, though not estimated, influence the orbit determination performance. We illustrate our results using two graphical presentations, which we call the variance sandpile'' and the sensitivity mosaic,'' and we compare the linear covariance results to confidence intervals associated with ensemble statistics from a Monte Carlo analysis.
Equipartitioning in linear accelerators
Jameson, R.A.
1982-01-01
Emittance growth has long been a concern in linear accelerators, as has the idea that some kind of energy balance, or equipartitioning, between the degrees of freedom, would ameliorate the growth. M. Prome observed that the average transverse and longitudinal velocity spreads tend to equalize as current in the channel is increased, while the sum of the energy in the system stays nearly constant. However, only recently have we shown that an equipartitioning requirement on a bunched injected beam can indeed produce remarkably small emittance growth. The simple set of equations leading to this condition are outlined. At the same time, Hofmann has investigated collective instabilities in transported beams and has identified thresholds and regions in parameter space where instabilities occur. Evidence is presented that shows transport system boundaries to be quite accurate in computer simulations of accelerating systems. Discussed are preliminary results of efforts to design accelerators that avoid parameter regions where emittance is affected by the instabilities identified by Hofmann. These efforts suggest that other mechanisms are present. The complicated behavior of the RFQ linac in this framework also is shown
Equipartitioning in linear accelerators
Jameson, R.A.
1981-01-01
Emittance growth has long been a concern in linear accelerators, as has the idea that some kind of energy balance, or equipartitioning, between the degrees of freedom, would ameliorate the growth. M. Prome observed that the average transverse and longitudinal velocity spreads tend to equalize as current in the channel is increased, while the sum of the energy in the system stays nearly constant. However, only recently have we shown that an equipartitioning requirement on a bunched injected beam can indeed produce remarkably small emittance growth. The simple set of equations leading to this condition are outlined below. At the same time, Hofmann, using powerful analytical and computational methods, has investigated collective instabilities in transported beams and has identified thresholds and regions in parameter space where instabilities occur. This is an important generalization. Work that he will present at this conference shows that the results are essentially the same in r-z coordinates for transport systems, and evidence is presented that shows transport system boundaries to be quite accurate in computer simulations of accelerating systems also. Discussed are preliminary results of efforts to design accelerators that avoid parameter regions where emittance is affected by the instabilities identified by Hofmann. These efforts suggest that other mechanisms are present. The complicated behavior of the RFQ linac in this framework also is shown
Briggs, R.J.
1986-06-01
The development of linear induction accelerators has been motivated by applications requiring high-pulsed currents of charged particles at voltages exceeding the capability of single-stage, diode-type accelerators and at currents too high for rf accelerators. In principle, one can accelerate charged particles to arbitrarily high voltages using a multi-stage induction machine, but the 50-MeV, 10-kA Advanced Test Accelerator (ATA) at LLNL is the highest voltage machine in existence at this time. The advent of magnetic pulse power systems makes sustained operation at high-repetition rates practical, and this capability for high-average power is very likely to open up many new applications of induction machines in the future. This paper surveys the US induction linac technology with primary emphasis on electron machines. A simplified description of how induction machines couple energy to the electron beam is given, to illustrate many of the general issues that bound the design space of induction linacs
Berkeley Proton Linear Accelerator
Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.
1953-10-13
A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.
RFQ device for accelerating particles
Shepard, K.W.; Delayen, J.R.
1995-06-06
A superconducting radio frequency quadrupole (RFQ) device includes four spaced elongated, linear, tubular rods disposed parallel to a charged particle beam axis, with each rod supported by two spaced tubular posts oriented radially with respect to the beam axis. The rod and post geometry of the device has four-fold rotation symmetry, lowers the frequency of the quadrupole mode below that of the dipole mode, and provides large dipole-quadrupole mode isolation to accommodate a range of mechanical tolerances. The simplicity of the geometry of the structure, which can be formed by joining eight simple T-sections, provides a high degree of mechanical stability, is insensitive to mechanical displacement, and is particularly adapted for fabrication with superconducting materials such as niobium. 5 figs.
RFQ device for accelerating particles
Shepard, Kenneth W. (Park Ridge, IL); Delayen, Jean R. (Naperville, IL)
1995-01-01
A superconducting radio frequency quadrupole (RFQ) device includes four spaced elongated, linear, tubular rods disposed parallel to a charged particle beam axis, with each rod supported by two spaced tubular posts oriented radially with respect to the beam axis. The rod and post geometry of the device has four-fold rotation symmetry, lowers the frequency of the quadrupole mode below that of the dipole mode, and provides large dipole-quadrupole mode isolation to accommodate a range of mechanical tolerances. The simplicity of the geometry of the structure, which can be formed by joining eight simple T-sections, provides a high degree of mechanical stability, is insensitive to mechanical displacement, and is particularly adapted for fabrication with superconducting materials such as niobium.
Random linear codes in steganography
Kamil Kaczyński
2016-12-01
Full Text Available Syndrome coding using linear codes is a technique that allows improvement in the steganographic algorithms parameters. The use of random linear codes gives a great flexibility in choosing the parameters of the linear code. In parallel, it offers easy generation of parity check matrix. In this paper, the modification of LSB algorithm is presented. A random linear code [8, 2] was used as a base for algorithm modification. The implementation of the proposed algorithm, along with practical evaluation of algorithms’ parameters based on the test images was made.[b]Keywords:[/b] steganography, random linear codes, RLC, LSB
2011-01-01
The present invention relates to a device for limiting movements in one or more anatomical joints, such as a device for limiting movement in the human hip joint after hip replacement surgery. This is provided by a device for limiting movement in the human hip joint, said device comprising: at least...
2007-01-01
The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention is a...
Semiconductor devices for all-optical regeneration
Öhman, Filip; Bischoff, Svend; Tromborg, Bjarne
2003-01-01
We review different implementations of semiconductor devices for all-optical regeneration. A general model will be presented for all-optical regeneration in fiber links, taking into consideration the trade-off between non-linearity and noise. Furthermore we discuss a novel regenerator type, based...
Industrial installation surveillance acoustic device
Marini, Jean; Audenard, Bernard.
1981-01-01
The purpose of this invention is the detection of possible impacts of bodies migrating inside the installation, using acoustic sensors of the waves emitted at the time of impact of the migrating bodies. This device makes it possible to take into account only those acoustic signals relating to the impacts of bodies migrating in the area under surveillance, to the exclusion of any other acoustic or electric perturbing phenomenon. The invention has a preferential use in the case of a linear shape installation in which a fluid flows at high rate, such as a section of the primary system of a pressurized water nuclear reactor [fr
Anderson, O.A.; Baker, W.R.; Ise, J. Jr.; Kunkel, W.B.; Pyle, R.V.; Stone, J.M.
1958-01-01
Three types of sheet-like discharges are being studied at Berkeley. The first of these, which has been given the name 'Triax', consists of a cylindrical plasma sleeve contained between two coaxial conducting cylinders A theoretical analysis of the stability of the cylindrical sheet plasma predicts the existence of a 'sausage-mode' instability which is, however, expected to grow more slowly than in the case of the unstabilized linear pinch (by the ratio of the radial dimensions). The second pinch device employs a disk shaped discharge with radial current guided between flat metal plates, this configuration being identical to that of the flat hydromagnetic capacitor without external magnetic field. A significant feature of these configurations is the absence of a plasma edge, i.e., there are no regions of sharply curved magnetic field lines anywhere in these discharges. The importance of this fact for stability is not yet fully investigated theoretically. As a third configuration a rectangular, flat pinch tube has been constructed, and the behaviour of a flat plasma sheet with edges is being studied experimentally
Power source device for thermonuclear device
Ozaki, Akira.
1992-01-01
The present invention provides a small sized and economical power source device for a thermonuclear device. That is, the device comprises a conversion device having a rated power determined by a power required during a plasma current excitation period and a conversion device having a rated power determined by a power required during a plasma current maintaining period, connected in series to each other. Then, for the former conversion device, power is supplied from an electric power generator and, for the latter, power is supplied from a power system. With such a constitution, during the plasma electric current maintaining period for substantially continuous operation, it is possible to conduct bypassing paired operation for the former conversion device while the electric power generator is put under no load. Further, since a short period rated power may be suffice for the former conversion device and the electric power generator having the great rated power required for the plasma electric current excitation period, they can be reduced in the size and made economical. On the other hand, since the power required for the plasma current maintaining period is relatively small, the capacity of the continuous rated conversion device may be small, and the power can be received from the power system. (I.S.)
Ultra-Compact linear chirped microwave signal generator
Yan, Siqi; Zhou, Feng; Dong, Jianji
2017-01-01
A novel concept to generate linear chirped microwave signal is proposed and experimentally verified. The frequency to time mapping method is used while the Mach-Zehnder interferometer based on the photonic crystal waveguide is employed as the key device with its significant advantages of the ultra...
A data-acquisition system for high speed linear CCD
Liu Zhiyan; Chen Xiangcai; Jiang Xiaoshan; Zhang Hongyu; Liang Zhongwang; Xiang Haisheng; Hu Jun
2010-01-01
A data-acquisition system for high speed linear CCD (Charge Coupled device) is mainly introduced. The optical fiber transmission technology is used. The data is sent to PC through USB or PCI interface. The construction of the system, the design of the PCI interface hardware, software design and the design of the control program running on host computer are also introduced. (authors)
High-density ionization with an intense linear focus discharge
Lee, T.N.
1975-01-01
Some experimental results obtained with a linear focus device are described. Measurements include plasma diagnostics made with fast photography, pinhole x-ray photography, and x-ray spectroscopy in the photon energy range of 6 to 35 0 keV. (MOW)
Gibelli, Daniele; Pucciarelli, Valentina; Cappella, Annalisa; Dolci, Claudia; Sforza, Chiarella
2018-01-31
Modern 3-dimensional (3D) image acquisition systems represent a crucial technologic development in facial anatomy because of their accuracy and precision. The recently introduced portable devices can improve facial databases by increasing the number of applications. In the present study, the VECTRA H1 portable stereophotogrammetric device was validated to verify its applicability to 3D facial analysis. Fifty volunteers underwent 4 facial scans using portable VECTRA H1 and static VECTRA M3 devices (2 for each instrument). Repeatability of linear, angular, surface area, and volume measurements was verified within the device and between devices using the Bland-Altman test and the calculation of absolute and relative technical errors of measurement (TEM and rTEM, respectively). In addition, the 2 scans obtained by the same device and the 2 scans obtained by different devices were registered and superimposed to calculate the root mean square (RMS; point-to-point) distance between the 2 surfaces. Most linear, angular, and surface area measurements had high repeatability in M3 versus M3, H1 versus H1, and M3 versus H1 comparisons (range, 82.2 to 98.7%; TEM range, 0.3 to 2.0 mm, 0.4° to 1.8°; rTEM range, 0.2 to 3.1%). In contrast, volumes and RMS distances showed evident differences in M3 versus M3 and H1 versus H1 comparisons and reached the maximum when scans from the 2 different devices were compared. The portable VECTRA H1 device proved reliable for assessing linear measurements, angles, and surface areas; conversely, the influence of involuntary facial movements on volumes and RMS distances was more important compared with the static device. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.
Linear Algebraic Method for Non-Linear Map Analysis
Yu, L.; Nash, B.
2009-01-01
We present a newly developed method to analyze some non-linear dynamics problems such as the Henon map using a matrix analysis method from linear algebra. Choosing the Henon map as an example, we analyze the spectral structure, the tune-amplitude dependence, the variation of tune and amplitude during the particle motion, etc., using the method of Jordan decomposition which is widely used in conventional linear algebra.
All-Pass Filter Based Linear Voltage Controlled Quadrature Oscillator
Koushick Mathur
2017-01-01
Full Text Available A linear voltage controlled quadrature oscillator implemented from a first-order electronically tunable all-pass filter (ETAF is presented. The active element is commercially available current feedback amplifier (AD844 in conjunction with the relatively new Multiplication Mode Current Conveyor (MMCC device. Electronic tunability is obtained by the control node voltage (V of the MMCC. Effects of the device nonidealities, namely, the parasitic capacitors and the roll-off poles of the port-transfer ratios of the device, are shown to be negligible, even though the usable high-frequency ranges are constrained by these imperfections. Subsequently the filter is looped with an electronically tunable integrator (ETI to implement the quadrature oscillator (QO. Experimental responses on the voltage tunable phase of the filter and the linear-tuning law of the quadrature oscillator up to 9.9 MHz at low THD are verified by simulation and hardware tests.
Diamond-shaped electromagnetic transparent devices with homogeneous material parameters
Li Tinghua; Huang Ming; Yang Jingjing; Yu Jiang; Lan Yaozhong
2011-01-01
Based on the linear coordinate transformation method, two-dimensional and three-dimensional electromagnetic transparent devices with diamond shape composed of homogeneous and non-singular materials are proposed in this paper. The permittivity and permeability tensors of the transparent devices are derived. The performance and scattering properties of the transparent devices are confirmed by a full-wave simulation. It can physically protect electric devices such as an antenna and a radar station inside, without sacrificing their performance. This work represents important progress towards the practical realization of metamaterial-assisted transparent devices and expands the application of transformation optics.
Experimental program based on a High Beta Q Machine. Final report, 1 May 1978-30 September 1980
Ribe, F.L.
1980-07-01
This report summarizes work done in designing and constructing the High Beta Q Machine from the inception of the work in May 1978 until the present time. It is a 3-m long, low-compression theta pinch with a 22-cm-diameter segmented compression coil with a minimum axial periodicity length of 10 cm. This capability of driving the machine as a simple, low-density theta pinch, and also of independently applying periodic magnetic fields before or after formation of the plasma column, gives the device considerable flexibility. Reported here is the construction and testing of the machine, development of its diagnostics and initial measurements of the plasma at early times in the duration of the crowbarred magnetic field. The experimental effort has been paralleled by theoretical work to model the diffuse profile, collisionless plasma in its response to the periodic RF magnetic fields. The model chosen is the Freidberg-Pearlstein Vlasov-fluid model which provides an MHD-like description but with accounting of ion kinetic effects over diffuse equilibrium profiles. A computer code has been developed to accurately calculate the resistive response of the plasma column, giving the power absorption by ion Landau damping and more recently, ion-cyclotron damping
Engineering feasibility evaluation of a peristaltic pinch
Boicourt, G.P.
1977-04-01
A recent proposal for reducing the end loss of a linear theta pinch is to produce moving magnetic mirrors at the coil ends. The concept entails the sequential pulsing of an axially arranged series of two-turn coaxial coils. The electrical design of such a system presents some unique problems. Ideally, the individual pulse circuits should be completely independent. This would facilitate the design by eliminating interactive effects. In practice, the circuits must be interconnected through isolating inductors to enable the production of a uniform biasing magnetic field. Moreover, the coils must be located physically close together. This produces strong magnetic coupling between the pulse circuits, which can seriously affect the shape and speed of the inward-moving magnetic-mirror field. Possible systems were modeled for the NET-2 circuit analysis code. The models took account of the inductive coupling between the individual circuits in the model. The results show that an increasing magnetic mirror can be produced provided the radius of the theta pinch is not too great compared to the intercoil spacing. The peristaltic field can be maintained for several cycles in the inner coils. The voltage hold-off requirements on the pulse circuit switches are found to be severe, but not impossible to meet
Linear Programming and Network Flows
Bazaraa, Mokhtar S; Sherali, Hanif D
2011-01-01
The authoritative guide to modeling and solving complex problems with linear programming-extensively revised, expanded, and updated The only book to treat both linear programming techniques and network flows under one cover, Linear Programming and Network Flows, Fourth Edition has been completely updated with the latest developments on the topic. This new edition continues to successfully emphasize modeling concepts, the design and analysis of algorithms, and implementation strategies for problems in a variety of fields, including industrial engineering, management science, operations research
Automating linear accelerator quality assurance.
Eckhause, Tobias; Al-Hallaq, Hania; Ritter, Timothy; DeMarco, John; Farrey, Karl; Pawlicki, Todd; Kim, Gwe-Ya; Popple, Richard; Sharma, Vijeshwar; Perez, Mario; Park, SungYong; Booth, Jeremy T; Thorwarth, Ryan; Moran, Jean M
2015-10-01
The purpose of this study was 2-fold. One purpose was to develop an automated, streamlined quality assurance (QA) program for use by multiple centers. The second purpose was to evaluate machine performance over time for multiple centers using linear accelerator (Linac) log files and electronic portal images. The authors sought to evaluate variations in Linac performance to establish as a reference for other centers. The authors developed analytical software tools for a QA program using both log files and electronic portal imaging device (EPID) measurements. The first tool is a general analysis tool which can read and visually represent data in the log file. This tool, which can be used to automatically analyze patient treatment or QA log files, examines the files for Linac deviations which exceed thresholds. The second set of tools consists of a test suite of QA fields, a standard phantom, and software to collect information from the log files on deviations from the expected values. The test suite was designed to focus on the mechanical tests of the Linac to include jaw, MLC, and collimator positions during static, IMRT, and volumetric modulated arc therapy delivery. A consortium of eight institutions delivered the test suite at monthly or weekly intervals on each Linac using a standard phantom. The behavior of various components was analyzed for eight TrueBeam Linacs. For the EPID and trajectory log file analysis, all observed deviations which exceeded established thresholds for Linac behavior resulted in a beam hold off. In the absence of an interlock-triggering event, the maximum observed log file deviations between the expected and actual component positions (such as MLC leaves) varied from less than 1% to 26% of published tolerance thresholds. The maximum and standard deviations of the variations due to gantry sag, collimator angle, jaw position, and MLC positions are presented. Gantry sag among Linacs was 0.336 ± 0.072 mm. The standard deviation in MLC
Hardness Assurance Techniques for New Generation COTS Devices
Lee, C. I.; Rax, B. G.; Johnston, A. H.
1996-01-01
Hardness Assurance (HA) techniques and total dose radiation characterization data for new generation linear and COTS devices from various manufacturers are presented. A bipolar op amp showed significant degradation at HDR, not at low dose rate environment. New generation low-power op amps showed more degradation at low voltage applications. HA test techniques for COTS devices are presented in this paper.
LINEAR2007, Linear-Linear Interpolation of ENDF Format Cross-Sections
2007-01-01
1 - Description of program or function: LINEAR converts evaluated cross sections in the ENDF/B format into a tabular form that is subject to linear-linear interpolation in energy and cross section. The code also thins tables of cross sections already in that form. Codes used subsequently need thus to consider only linear-linear data. IAEA1311/15: This version include the updates up to January 30, 2007. Changes in ENDF/B-VII Format and procedures, as well as the evaluations themselves, make it impossible for versions of the ENDF/B pre-processing codes earlier than PREPRO 2007 (2007 Version) to accurately process current ENDF/B-VII evaluations. The present code can handle all existing ENDF/B-VI evaluations through release 8, which will be the last release of ENDF/B-VI. Modifications from previous versions: - Linear VERS. 2007-1 (JAN. 2007): checked against all ENDF/B-VII; increased page size from 60,000 to 600,000 points 2 - Method of solution: Each section of data is considered separately. Each section of File 3, 23, and 27 data consists of a table of cross section versus energy with any of five interpolation laws. LINEAR will replace each section with a new table of energy versus cross section data in which the interpolation law is always linear in energy and cross section. The histogram (constant cross section between two energies) interpolation law is converted to linear-linear by substituting two points for each initial point. The linear-linear is not altered. For the log-linear, linear-log and log- log laws, the cross section data are converted to linear by an interval halving algorithm. Each interval is divided in half until the value at the middle of the interval can be approximated by linear-linear interpolation to within a given accuracy. The LINEAR program uses a multipoint fractional error thinning algorithm to minimize the size of each cross section table
Elementary linear programming with applications
Kolman, Bernard
1995-01-01
Linear programming finds the least expensive way to meet given needs with available resources. Its results are used in every area of engineering and commerce: agriculture, oil refining, banking, and air transport. Authors Kolman and Beck present the basic notions of linear programming and illustrate how they are used to solve important common problems. The software on the included disk leads students step-by-step through the calculations. The Second Edition is completely revised and provides additional review material on linear algebra as well as complete coverage of elementary linear program
Hood, John Linsley
2013-01-01
The Art of Linear Electronics presents the principal aspects of linear electronics and techniques in linear electronic circuit design. The book provides a wide range of information on the elucidation of the methods and techniques in the design of linear electronic circuits. The text discusses such topics as electronic component symbols and circuit drawing; passive and active semiconductor components; DC and low frequency amplifiers; and the basic effects of feedback. Subjects on frequency response modifying circuits and filters; audio amplifiers; low frequency oscillators and waveform generato
Linearity and Non-linearity of Photorefractive effect in Materials ...
Linearity and Non-linearity of Photorefractive effect in Materials using the Band transport ... For low light beam intensities the change in the refractive index is ... field is spatially phase shifted by /2 relative to the interference fringe pattern, which ...
The linear programming bound for binary linear codes
Brouwer, A.E.
1993-01-01
Combining Delsarte's (1973) linear programming bound with the information that certain weights cannot occur, new upper bounds for dmin (n,k), the maximum possible minimum distance of a binary linear code with given word length n and dimension k, are derived.
Linear operator inequalities for strongly stable weakly regular linear systems
Curtain, RF
2001-01-01
We consider the question of the existence of solutions to certain linear operator inequalities (Lur'e equations) for strongly stable, weakly regular linear systems with generating operators A, B, C, 0. These operator inequalities are related to the spectral factorization of an associated Popov
Linear and non-linear optics of condensed matter
McLean, T.P.
1977-01-01
Part I - Linear optics: 1. General introduction. 2. Frequency dependence of epsilon(ω, k vector). 3. Wave-vector dependence of epsilon(ω, k vector). 4. Tensor character of epsilon(ω, k vector). Part II - Non-linear optics: 5. Introduction. 6. A classical theory of non-linear response in one dimension. 7. The generalization to three dimensions. 8. General properties of the polarizability tensors. 9. The phase-matching condition. 10. Propagation in a non-linear dielectric. 11. Second harmonic generation. 12. Coupling of three waves. 13. Materials and their non-linearities. 14. Processes involving energy exchange with the medium. 15. Two-photon absorption. 16. Stimulated Raman effect. 17. Electro-optic effects. 18. Limitations of the approach presented here. (author)
Advanced statistics: linear regression, part I: simple linear regression.
Marill, Keith A
2004-01-01
Simple linear regression is a mathematical technique used to model the relationship between a single independent predictor variable and a single dependent outcome variable. In this, the first of a two-part series exploring concepts in linear regression analysis, the four fundamental assumptions and the mechanics of simple linear regression are reviewed. The most common technique used to derive the regression line, the method of least squares, is described. The reader will be acquainted with other important concepts in simple linear regression, including: variable transformations, dummy variables, relationship to inference testing, and leverage. Simplified clinical examples with small datasets and graphic models are used to illustrate the points. This will provide a foundation for the second article in this series: a discussion of multiple linear regression, in which there are multiple predictor variables.
... Artery Disease Venous Thromboembolism Aortic Aneurysm More Implantable Medical Devices Updated:Sep 16,2016 For Rhythm Control ... a Heart Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack ...
... the sounds you want to hear. Assistive listening devices bring certain sounds directly to your ears. This can ... a small room or on a stage. Other devices can bring the sound from your TV, radio, or music ...
Schuller, Ivan
2007-01-01
...: ballistic magnetoresistance, magnetic field proximity effect and spin drag. These three phenomena would then be exploited for the design of novel device architectures and to investigate the physical principles behind these devices...
Advances in memristors, memristive devices and systems
Volos, Christos
2017-01-01
This book reports on the latest advances in and applications of memristors, memristive devices and systems. It gathers 20 contributed chapters by subject experts, including pioneers in the field such as Leon Chua (UC Berkeley, USA) and R.S. Williams (HP Labs, USA), who are specialized in the various topics addressed in this book, and covers broad areas of memristors and memristive devices such as: memristor emulators, oscillators, chaotic and hyperchaotic memristive systems, control of memristive systems, memristor-based min-max circuits, canonic memristors, memristive-based neuromorphic applications, implementation of memristor-based chaotic oscillators, inverse memristors, linear memristor devices, delayed memristive systems, flux-controlled memristive emulators, etc. Throughout the book, special emphasis is given to papers offering practical solutions and design, modeling, and implementation insights to address current research problems in memristors, memristive devices and systems. As such, it offers a va...
Progress of Terahertz Devices Based on Graphene
Mai-Xia Fu; Yan Zhang
2013-01-01
Graphene is a one-atom-thick planar sheet of sp2-hybridized orbital bonded honeycomb carbon crystal. Its gapless and linear energy spectra of electrons and holes lead to the unique carrier transport and optical properties, such as giant carrier mobility and broadband flat optical response. As a novel material, graphene has been regarded to be extremely suitable and competent for the development of terahertz (THz) optical devices. In this paper, the fundamental electronic and optic properties of graphene are described. Based on the energy band structure and light transmittance properties of graphene, many novel graphene based THz devices have been proposed, including modulator, generator, detector, and imaging device. This progress has been reviewed. Future research directions of the graphene devices for THz applications are also proposed.
Stisen, Allan; Blunck, Henrik; Bhattacharya, Sourav
2015-01-01
research results. This is due to variations in training and test device hardware and their operating system characteristics among others. In this paper, we systematically investigate sensor-, device- and workload-specific heterogeneities using 36 smartphones and smartwatches, consisting of 13 different...... device models from four manufacturers. Furthermore, we conduct experiments with nine users and investigate popular feature representation and classification techniques in HAR research. Our results indicate that on-device sensor and sensor handling heterogeneities impair HAR performances significantly...
Heterostructures and quantum devices
Einspruch, Norman G
1994-01-01
Heterostructure and quantum-mechanical devices promise significant improvement in the performance of electronic and optoelectronic integrated circuits (ICs). Though these devices are the subject of a vigorous research effort, the current literature is often either highly technical or narrowly focused. This book presents heterostructure and quantum devices to the nonspecialist, especially electrical engineers working with high-performance semiconductor devices. It focuses on a broad base of technical applications using semiconductor physics theory to develop the next generation of electrical en
2015-09-01
1. Overview The purpose of this document is to demonstrate how to gain administrative privileges on an Android device. The term “rooting” is...is applicable for the Samsung Galaxy S3 as well as many other Android devices, but there are several steps involved in rooting an Android device (as...root access has been granted. 4. Conclusion This document serves as a tutorial on how to grant user administrative privilege to an Android device by
Crasmareanu Mircea
2017-12-01
Full Text Available We consider the paracomplex version of the notion of mixed linear spaces introduced by M. Jurchescu in [4] by replacing the complex unit i with the paracomplex unit j, j2 = 1. The linear algebra of these spaces is studied with a special view towards their morphisms.
Linear Algebra and Image Processing
Allali, Mohamed
2010-01-01
We use the computing technology digital image processing (DIP) to enhance the teaching of linear algebra so as to make the course more visual and interesting. Certainly, this visual approach by using technology to link linear algebra to DIP is interesting and unexpected to both students as well as many faculty. (Contains 2 tables and 11 figures.)
Efficient Searching with Linear Constraints
Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff
2000-01-01
We show how to preprocess a set S of points in d into an external memory data structure that efficiently supports linear-constraint queries. Each query is in the form of a linear constraint xd a0+∑d−1i=1 aixi; the data structure must report all the points of S that satisfy the constraint. This pr...
Johnson, Bruce G.; Gerver, Michael J.; Hawkey, Timothy J.; Fenn, Ralph C.
1993-01-01
Improved linear actuator comprises air slide and linear electric motor. Unit exhibits low friction, low backlash, and more nearly even acceleration. Used in machinery in which positions, velocities, and accelerations must be carefully controlled and/or vibrations must be suppressed.
Linear morphoea follows Blaschko's lines.
Weibel, L; Harper, J I
2008-07-01
The aetiology of morphoea (or localized scleroderma) remains unknown. It has previously been suggested that lesions of linear morphoea may follow Blaschko's lines and thus reflect an embryological development. However, the distribution of linear morphoea has never been accurately evaluated. We aimed to identify common patterns of clinical presentation in children with linear morphoea and to establish whether linear morphoea follows the lines of Blaschko. A retrospective chart review of 65 children with linear morphoea was performed. According to clinical photographs the skin lesions of these patients were plotted on to standardized head and body charts. With the aid of Adobe Illustrator a final figure was produced including an overlay of all individual lesions which was used for comparison with the published lines of Blaschko. Thirty-four (53%) patients had the en coup de sabre subtype, 27 (41%) presented with linear morphoea on the trunk and/or limbs and four (6%) children had a combination of the two. In 55 (85%) children the skin lesions were confined to one side of the body, showing no preference for either left or right side. On comparing the overlays of all body and head lesions with the original lines of Blaschko there was an excellent correlation. Our data indicate that linear morphoea follows the lines of Blaschko. We hypothesize that in patients with linear morphoea susceptible cells are present in a mosaic state and that exposure to some trigger factor may result in the development of this condition.
Campagnoli, Patrizia; Petris, Giovanni
2009-01-01
State space models have gained tremendous popularity in as disparate fields as engineering, economics, genetics and ecology. Introducing general state space models, this book focuses on dynamic linear models, emphasizing their Bayesian analysis. It illustrates the fundamental steps needed to use dynamic linear models in practice, using R package.
Linear Programming across the Curriculum
Yoder, S. Elizabeth; Kurz, M. Elizabeth
2015-01-01
Linear programming (LP) is taught in different departments across college campuses with engineering and management curricula. Modeling an LP problem is taught in every linear programming class. As faculty teaching in Engineering and Management departments, the depth to which teachers should expect students to master this particular type of…
Introduction to RF linear accelerators
Weiss, M.
1994-01-01
The basic features of RF linear accelerators are described. The concept of the 'loaded cavity', essential for the synchronism wave-particle, is introduced, and formulae describing the action of electromagnetic fields on the beam are given. The treatment of intense beams is mentioned, and various existing linear accelerators are presented as examples. (orig.)
Spatial Processes in Linear Ordering
von Hecker, Ulrich; Klauer, Karl Christoph; Wolf, Lukas; Fazilat-Pour, Masoud
2016-01-01
Memory performance in linear order reasoning tasks (A > B, B > C, C > D, etc.) shows quicker, and more accurate responses to queries on wider (AD) than narrower (AB) pairs on a hypothetical linear mental model (A -- B -- C -- D). While indicative of an analogue representation, research so far did not provide positive evidence for spatial…
Andersen, O. Krogh
1975-01-01
of Korringa-Kohn-Rostoker, linear-combination-of-atomic-orbitals, and cellular methods; the secular matrix is linear in energy, the overlap integrals factorize as potential parameters and structure constants, the latter are canonical in the sense that they neither depend on the energy nor the cell volume...
Introduction to generalized linear models
Dobson, Annette J
2008-01-01
Introduction Background Scope Notation Distributions Related to the Normal Distribution Quadratic Forms Estimation Model Fitting Introduction Examples Some Principles of Statistical Modeling Notation and Coding for Explanatory Variables Exponential Family and Generalized Linear Models Introduction Exponential Family of Distributions Properties of Distributions in the Exponential Family Generalized Linear Models Examples Estimation Introduction Example: Failure Times for Pressure Vessels Maximum Likelihood Estimation Poisson Regression Example Inference Introduction Sampling Distribution for Score Statistics Taylor Series Approximations Sampling Distribution for MLEs Log-Likelihood Ratio Statistic Sampling Distribution for the Deviance Hypothesis Testing Normal Linear Models Introduction Basic Results Multiple Linear Regression Analysis of Variance Analysis of Covariance General Linear Models Binary Variables and Logistic Regression Probability Distributions ...
Acoustic emission linear pulse holography
Collins, H.D.; Busse, L.J.; Lemon, D.K.
1983-01-01
This paper describes the emission linear pulse holography which produces a chronological linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. A thirty two point sampling array is used to construct phase-only linear holograms of simulated acoustic emission sources on large metal plates. The concept behind the AE linear pulse holography is illustrated, and a block diagram of a data acquisition system to implement the concept is given. Array element spacing, synthetic frequency criteria, and lateral depth resolution are specified. A reference timing transducer positioned between the array and the inspection zone and which inititates the time-of-flight measurements is described. The results graphically illustrate the technique using a one-dimensional FFT computer algorithm (ie. linear backward wave) for an AE image reconstruction
Photovoltaic device and method
Cleereman, Robert J; Lesniak, Michael J; Keenihan, James R; Langmaid, Joe A; Gaston, Ryan; Eurich, Gerald K; Boven, Michelle L
2015-01-27
The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.
Radioactive waste processing device
Inaguma, Masahiko; Takahara, Nobuaki; Hara, Satomi.
1996-01-01
In a processing device for filtering laundry liquid wastes and shower drains incorporated with radioactive materials, a fiber filtration device is disposed and an activated carbon filtration device is also disposed subsequent to the fiber filtration device. In addition, a centrifugal dewatering device is disposed for dewatering spent granular activated carbon in the activated carbon filtration device, and a minute filtering device is disposed for filtering the separated dewatering liquid. Filtrates filtered by the minute filtration device are recovered in a collecting tank. Namely, at first, suspended solid materials in laundry liquid wastes and shower drains are captured, and then, ingredients concerning COD are adsorbed in the activated carbon filtration device. The radioactive liquid wastes of spent granular activated carbon in the activated carbon filtration device are reduced by dewatering them by the centrifugal dewatering device, and then the granular activated carbon is subjected to an additional processing. Further, it is separated by filtration using the minute filtration device and removed as cakes. Since the filtrates are recovered to the collecting tank and filtered again, the water quality of the drains is not degraded. (N.H.)
Nagaoka, Etsuo.
1996-01-01
The present invention provides an inspection device in PWR reactor core in which inspection operations are made efficient by stabilizing a posture of the device in front-to-back, vertical and left-to-right directions by a simple structure. When the device conducts inspection while running in liquid, the front and the back directions of the device main body are inspected using a visual device while changing the posture by operating a front-to-back direction propulsion device and a right-to-left direction propulsion device, and a vertical direction propulsion device against to rolling, pitching and yawing of the device main body. In this case, a spherical magnet moves freely in the gravitational direction in a vibration-damping fluid in a non-magnetic spherical shell following the change of the posture of the device main body, in which the vibrations due to the movement of the spherical magnet is settled by the vibration-damping fluid thereby stabilizing the posture of the device main body. At a typical inspection posture, the settling effect is enhanced by the attraction force between the spherical magnets in the spherical shell and each of magnetic force-attracted magnetic members disposed to the outer circumference of the shell, and the posture of the device main body can be confirmed in front-to-back, right-to-left and vertical directions by each of the posture confirming magnetic sensors. (N.H.)
Containment and surveillance devices
Campbell, J.W.; Johnson, C.S.; Stieff, L.R.
The growing acceptance of containment and surveillance as a means to increase safeguards effectiveness has provided impetus to the development of improved surveillance and containment devices. Five recently developed devices are described. The devices include one photographic and two television surveillance systems and two high security seals that can be verified while installed
Radiation emitting devices act
1970-01-01
This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws
Hawley, W.W.
1983-03-29
A transportable solar panel foundation device which has a bottom member, at least one upstanding side member, and an essentially open top. The side members are angled to permit nesting of a plurality of the foundation devices, and reinforcement pads are carried by the foundation device to support legs for one or more solar panels.
Articulating feedstock delivery device
Jordan, Kevin
2013-11-05
A fully articulable feedstock delivery device that is designed to operate at pressure and temperature extremes. The device incorporates an articulating ball assembly which allows for more accurate delivery of the feedstock to a target location. The device is suitable for a variety of applications including, but not limited to, delivery of feedstock to a high-pressure reaction chamber or process zone.
Linear and Generalized Linear Mixed Models and Their Applications
Jiang, Jiming
2007-01-01
This book covers two major classes of mixed effects models, linear mixed models and generalized linear mixed models, and it presents an up-to-date account of theory and methods in analysis of these models as well as their applications in various fields. The book offers a systematic approach to inference about non-Gaussian linear mixed models. Furthermore, it has included recently developed methods, such as mixed model diagnostics, mixed model selection, and jackknife method in the context of mixed models. The book is aimed at students, researchers and other practitioners who are interested
Monitoring Linear Accelerator Output Constancy Using the PTW Linacheck
McDermott, Garry M.; Buckle, Andrew H.
2011-01-01
The PTW-Linacheck was assessed for its ability to monitor linear accelerator radiation output constancy. The key issues that were considered were the setup for daily output measurements, e.g., requirements for build-up and backscatter material, and the reproducibility and linearity of the device with linear accelerator output. An appropriate measurement setup includes a 10 x 10 cm field at 100 cm FSD, 5 cm backscatter, and no added build-up for 4 MeV electron beams, 1 cm added build-up for 6-16 MeV electron beams and 5 cm added build-up for 6-15 MV photon beams. Using this measurement setup, the dose linearity and short-term reproducibility were acceptable; however, the Linacheck should be recalibrated on a monthly basis to ensure acceptable long-term reproducibility.
A comparison between linear and toroidal Extrap systems
Lehnert, B.
1988-09-01
The Extrap scheme consists of a Z-pinch immersed in an octupole field generated by currents in a set of external conductors. A comparison between linear and toroidal Extrap geometry is made in this paper. As compared to toroidal systems, linear geometry has the advantages of relative simplicity and of a current drive by means of electrodes. Linear devices are convenient for basic studies of Extrap, at moderately high pinch currents and plasma temperatures. Within the parameter ranges of experiments at high pinch currents and plasma temperatures, linear systems have on the other hand some substantial disadvantages, on account of the plasma interaction with the end regions. This results in a limitation of the energy confinement time, and leads in the case of an ohmically heated plasma to excessively high plasma densities and small pinch radii which also complicate the introduction of the external conductors. (author)
Analytical Ballistic Trajectories with Approximately Linear Drag
Giliam J. P. de Carpentier
2014-01-01
Full Text Available This paper introduces a practical analytical approximation of projectile trajectories in 2D and 3D roughly based on a linear drag model and explores a variety of different planning algorithms for these trajectories. Although the trajectories are only approximate, they still capture many of the characteristics of a real projectile in free fall under the influence of an invariant wind, gravitational pull, and terminal velocity, while the required math for these trajectories and planners is still simple enough to efficiently run on almost all modern hardware devices. Together, these properties make the proposed approach particularly useful for real-time applications where accuracy and performance need to be carefully balanced, such as in computer games.
A High Power Linear Solid State Pulser
Boris Yen; Brent Davis; Rex Booth
1999-01-01
Particle Accelerators require high voltage and often high power. Typically the high voltage/power generation utilizes a topology with an extra energy store and a switching means to extract that stored energy. The switches may be active or passive devices. Active switches are hard or soft vacuum tubes, or semiconductors. When required voltages exceed tens of kilovolts, numerous semiconductors are stacked to withstand that potential. Such topologies can use large numbers of critical parts that, when in series, compromise the system reliability and performance. This paper describes a modular, linear, solid state amplifier which uses a parallel array of semiconductors, coupled with transmission line transformers. Such a design can provide output signals with voltages exceeding 10kV (into 50-ohms), and with rise and fall times (10-90 % amplitude) that are less than 1--ns. This compact solid state amplifier is modular, and has both hot-swap and soft fail capabilities
Precise linear gating circuit on integrated microcircuits
Butskii, V.V.; Vetokhin, S.S.; Reznikov, I.V.
Precise linear gating circuit on four microcircuits is described. A basic flowsheet of the gating circuit is given. The gating circuit consists of two input differential cascades total load of which is two current followers possessing low input and high output resistances. Follower outlets are connected to high ohmic dynamic load formed with a current source which permits to get high amplification (>1000) at one cascade. Nonlinearity amounts to <0.1% in the range of input signal amplitudes of -10-+10 V. Front duration for an output signal with 10 V amplitude amounts to 100 ns. Attenuation of input signal with a closed gating circuit is 60 db. The gating circuits described is used in the device intended for processing of scintillation sensor signals.
Ferencz, Donald C.; Viterna, Larry A.
1991-01-01
ALPS is a computer program which can be used to solve general linear program (optimization) problems. ALPS was designed for those who have minimal linear programming (LP) knowledge and features a menu-driven scheme to guide the user through the process of creating and solving LP formulations. Once created, the problems can be edited and stored in standard DOS ASCII files to provide portability to various word processors or even other linear programming packages. Unlike many math-oriented LP solvers, ALPS contains an LP parser that reads through the LP formulation and reports several types of errors to the user. ALPS provides a large amount of solution data which is often useful in problem solving. In addition to pure linear programs, ALPS can solve for integer, mixed integer, and binary type problems. Pure linear programs are solved with the revised simplex method. Integer or mixed integer programs are solved initially with the revised simplex, and the completed using the branch-and-bound technique. Binary programs are solved with the method of implicit enumeration. This manual describes how to use ALPS to create, edit, and solve linear programming problems. Instructions for installing ALPS on a PC compatible computer are included in the appendices along with a general introduction to linear programming. A programmers guide is also included for assistance in modifying and maintaining the program.
Linear and quasi-linear equations of parabolic type
Ladyženskaja, O A; Ural′ceva, N N; Uralceva, N N
1968-01-01
Equations of parabolic type are encountered in many areas of mathematics and mathematical physics, and those encountered most frequently are linear and quasi-linear parabolic equations of the second order. In this volume, boundary value problems for such equations are studied from two points of view: solvability, unique or otherwise, and the effect of smoothness properties of the functions entering the initial and boundary conditions on the smoothness of the solutions.
Radiation emitting devices regulations
1970-01-01
The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment
The Theory of Linear Prediction
Vaidyanathan, PP
2007-01-01
Linear prediction theory has had a profound impact in the field of digital signal processing. Although the theory dates back to the early 1940s, its influence can still be seen in applications today. The theory is based on very elegant mathematics and leads to many beautiful insights into statistical signal processing. Although prediction is only a part of the more general topics of linear estimation, filtering, and smoothing, this book focuses on linear prediction. This has enabled detailed discussion of a number of issues that are normally not found in texts. For example, the theory of vecto
Correlation and simple linear regression.
Zou, Kelly H; Tuncali, Kemal; Silverman, Stuart G
2003-06-01
In this tutorial article, the concepts of correlation and regression are reviewed and demonstrated. The authors review and compare two correlation coefficients, the Pearson correlation coefficient and the Spearman rho, for measuring linear and nonlinear relationships between two continuous variables. In the case of measuring the linear relationship between a predictor and an outcome variable, simple linear regression analysis is conducted. These statistical concepts are illustrated by using a data set from published literature to assess a computed tomography-guided interventional technique. These statistical methods are important for exploring the relationships between variables and can be applied to many radiologic studies.
Saravanan, R
2018-01-01
Non-linear optical materials have widespread and promising applications, but the efforts to understand the local structure, electron density distribution and bonding is still lacking. The present work explores the structural details, the electron density distribution and the local bond length distribution of some non-linear optical materials. It also gives estimation of the optical band gap, the particle size, crystallite size, and the elemental composition from UV-Visible analysis, SEM, XRD and EDS of some non-linear optical materials respectively.
Optimal control linear quadratic methods
Anderson, Brian D O
2007-01-01
This augmented edition of a respected text teaches the reader how to use linear quadratic Gaussian methods effectively for the design of control systems. It explores linear optimal control theory from an engineering viewpoint, with step-by-step explanations that show clearly how to make practical use of the material.The three-part treatment begins with the basic theory of the linear regulator/tracker for time-invariant and time-varying systems. The Hamilton-Jacobi equation is introduced using the Principle of Optimality, and the infinite-time problem is considered. The second part outlines the
Protector in a nuclear fusion device
Furukawa, Masayuki; Yamane, Katsumi; Niwa, Sadahiko; Ogata, Fumio; Masuda, Jun-ichi.
1975-01-01
Object: To block an abnormal voltage, which shifts from plasma to coil or power supply by means of action of mutual induction, by a circuit utilizing non-linear impedance elements. Structure: The nuclear fusion device includes a current transformer coil, a vertical field coil and a plasma circuit, with a non-linear impedance element disposed in parallel with at least the current transformer coil, said impedance element being disposed in parallel with a short-circuiting switch, relative to the abnormal voltage moving from the plasma by means of action of mutual induction. (Kamimura, M.)
Automating linear accelerator quality assurance
Eckhause, Tobias; Thorwarth, Ryan; Moran, Jean M.; Al-Hallaq, Hania; Farrey, Karl; Ritter, Timothy; DeMarco, John; Pawlicki, Todd; Kim, Gwe-Ya; Popple, Richard; Sharma, Vijeshwar; Park, SungYong; Perez, Mario; Booth, Jeremy T.
2015-01-01
Purpose: The purpose of this study was 2-fold. One purpose was to develop an automated, streamlined quality assurance (QA) program for use by multiple centers. The second purpose was to evaluate machine performance over time for multiple centers using linear accelerator (Linac) log files and electronic portal images. The authors sought to evaluate variations in Linac performance to establish as a reference for other centers. Methods: The authors developed analytical software tools for a QA program using both log files and electronic portal imaging device (EPID) measurements. The first tool is a general analysis tool which can read and visually represent data in the log file. This tool, which can be used to automatically analyze patient treatment or QA log files, examines the files for Linac deviations which exceed thresholds. The second set of tools consists of a test suite of QA fields, a standard phantom, and software to collect information from the log files on deviations from the expected values. The test suite was designed to focus on the mechanical tests of the Linac to include jaw, MLC, and collimator positions during static, IMRT, and volumetric modulated arc therapy delivery. A consortium of eight institutions delivered the test suite at monthly or weekly intervals on each Linac using a standard phantom. The behavior of various components was analyzed for eight TrueBeam Linacs. Results: For the EPID and trajectory log file analysis, all observed deviations which exceeded established thresholds for Linac behavior resulted in a beam hold off. In the absence of an interlock-triggering event, the maximum observed log file deviations between the expected and actual component positions (such as MLC leaves) varied from less than 1% to 26% of published tolerance thresholds. The maximum and standard deviations of the variations due to gantry sag, collimator angle, jaw position, and MLC positions are presented. Gantry sag among Linacs was 0.336 ± 0.072 mm. The
Automating linear accelerator quality assurance
Eckhause, Tobias; Thorwarth, Ryan; Moran, Jean M., E-mail: jmmoran@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109-5010 (United States); Al-Hallaq, Hania; Farrey, Karl [Department of Radiation Oncology and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States); Ritter, Timothy [Ann Arbor VA Medical Center, Ann Arbor, Michigan 48109 (United States); DeMarco, John [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California, 90048 (United States); Pawlicki, Todd; Kim, Gwe-Ya [UCSD Medical Center, La Jolla, California 92093 (United States); Popple, Richard [Department of Radiation Oncology, University of Alabama Birmingham, Birmingham, Alabama 35249 (United States); Sharma, Vijeshwar; Park, SungYong [Karmanos Cancer Institute, McLaren-Flint, Flint, Michigan 48532 (United States); Perez, Mario; Booth, Jeremy T. [Royal North Shore Hospital, Sydney, NSW 2065 (Australia)
2015-10-15
Purpose: The purpose of this study was 2-fold. One purpose was to develop an automated, streamlined quality assurance (QA) program for use by multiple centers. The second purpose was to evaluate machine performance over time for multiple centers using linear accelerator (Linac) log files and electronic portal images. The authors sought to evaluate variations in Linac performance to establish as a reference for other centers. Methods: The authors developed analytical software tools for a QA program using both log files and electronic portal imaging device (EPID) measurements. The first tool is a general analysis tool which can read and visually represent data in the log file. This tool, which can be used to automatically analyze patient treatment or QA log files, examines the files for Linac deviations which exceed thresholds. The second set of tools consists of a test suite of QA fields, a standard phantom, and software to collect information from the log files on deviations from the expected values. The test suite was designed to focus on the mechanical tests of the Linac to include jaw, MLC, and collimator positions during static, IMRT, and volumetric modulated arc therapy delivery. A consortium of eight institutions delivered the test suite at monthly or weekly intervals on each Linac using a standard phantom. The behavior of various components was analyzed for eight TrueBeam Linacs. Results: For the EPID and trajectory log file analysis, all observed deviations which exceeded established thresholds for Linac behavior resulted in a beam hold off. In the absence of an interlock-triggering event, the maximum observed log file deviations between the expected and actual component positions (such as MLC leaves) varied from less than 1% to 26% of published tolerance thresholds. The maximum and standard deviations of the variations due to gantry sag, collimator angle, jaw position, and MLC positions are presented. Gantry sag among Linacs was 0.336 ± 0.072 mm. The
Cellular Automata Rules and Linear Numbers
Nayak, Birendra Kumar; Sahoo, Sudhakar; Biswal, Sagarika
2012-01-01
In this paper, linear Cellular Automta (CA) rules are recursively generated using a binary tree rooted at "0". Some mathematical results on linear as well as non-linear CA rules are derived. Integers associated with linear CA rules are defined as linear numbers and the properties of these linear numbers are studied.
Feedback systems for linear colliders
Hendrickson, L; Himel, Thomas M; Minty, Michiko G; Phinney, N; Raimondi, Pantaleo; Raubenheimer, T O; Shoaee, H; Tenenbaum, P G
1999-01-01
Feedback systems are essential for stable operation of a linear collider, providing a cost-effective method for relaxing tight tolerances. In the Stanford Linear Collider (SLC), feedback controls beam parameters such as trajectory, energy, and intensity throughout the accelerator. A novel dithering optimization system which adjusts final focus parameters to maximize luminosity contributed to achieving record performance in the 1997-98 run. Performance limitations of the steering feedback have been investigated, and improvements have been made. For the Next Linear Collider (NLC), extensive feedback systems are planned as an intregal part of the design. Feedback requiremetns for JLC (the Japanese Linear Collider) are essentially identical to NLC; some of the TESLA requirements are similar but there are significant differences. For NLC, algorithms which incorporate improvements upon the SLC implementation are being prototyped. Specialized systems for the damping rings, rf and interaction point will operate at hi...
An introduction to linear algebra
Mirsky, L
2003-01-01
Rigorous, self-contained coverage of determinants, vectors, matrices and linear equations, quadratic forms, more. Elementary, easily readable account with numerous examples and problems at the end of each chapter.
CLIC: developing a linear collider
Laurent Guiraud
1999-01-01
Compact Linear Collider (CLIC) is a CERN project to provide high-energy electron-positron collisions. Instead of conventional radio-frequency klystrons, CLIC will use a low-energy, high-intensity primary beam to produce acceleration.
1988 linear accelerator conference proceedings
1989-06-01
This report contains papers presented at the 1988 Linear Accelerator Conference. A few topics covered are beam dynamics; beam transport; superconducting components; free electron lasers; ion sources; and klystron research
CERN balances linear collider studies
ILC Newsline
2011-01-01
The forces behind the two most mature proposals for a next-generation collider, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) study, have been steadily coming together, with scientists from both communities sharing ideas and information across the technology divide. In a support of cooperation between the two, CERN in Switzerland, where most CLIC research takes place, recently converted the project-specific position of CLIC Study Leader to the concept-based Linear Collider Study Leader. The scientist who now holds this position, Steinar Stapnes, is charged with making the linear collider a viable option for CERN’s future, one that could include either CLIC or the ILC. The transition to more involve the ILC must be gradual, he said, and the redefinition of his post is a good start. Though not very much involved with superconducting radiofrequency (SRF) technology, where ILC researchers have made significant advances, CERN participates in many aspect...
Linear Methods for Image Interpolation
Pascal Getreuer
2011-01-01
We discuss linear methods for interpolation, including nearest neighbor, bilinear, bicubic, splines, and sinc interpolation. We focus on separable interpolation, so most of what is said applies to one-dimensional interpolation as well as N-dimensional separable interpolation.
Klumpp, A. R.; Lawson, C. L.
1988-01-01
Routines provided for common scalar, vector, matrix, and quaternion operations. Computer program extends Ada programming language to include linear-algebra capabilities similar to HAS/S programming language. Designed for such avionics applications as software for Space Station.
Functionalized linear and cyclic polyolefins
Tuba, Robert; Grubbs, Robert H.
2018-02-13
This invention relates to methods and compositions for preparing linear and cyclic polyolefins. More particularly, the invention relates to methods and compositions for preparing functionalized linear and cyclic polyolefins via olefin metathesis reactions. Polymer products produced via the olefin metathesis reactions of the invention may be utilized for a wide range of materials applications. The invention has utility in the fields of polymer and materials chemistry and manufacture.
Rumen Daskalov
2017-07-01
Full Text Available Let an $[n,k,d]_q$ code be a linear code of length $n$, dimension $k$ and minimum Hamming distance $d$ over $GF(q$. One of the most important problems in coding theory is to construct codes with optimal minimum distances. In this paper 22 new ternary linear codes are presented. Two of them are optimal. All new codes improve the respective lower bounds in [11].
Explorative methods in linear models
Høskuldsson, Agnar
2004-01-01
The author has developed the H-method of mathematical modeling that builds up the model by parts, where each part is optimized with respect to prediction. Besides providing with better predictions than traditional methods, these methods provide with graphic procedures for analyzing different feat...... features in data. These graphic methods extend the well-known methods and results of Principal Component Analysis to any linear model. Here the graphic procedures are applied to linear regression and Ridge Regression....
Polarized Electrons for Linear Colliders
Clendenin, J.
2004-01-01
Future electron-positron linear colliders require a highly polarized electron beam with a pulse structure that depends primarily on whether the acceleration utilizes warm or superconducting rf structures. The International Linear Collider (ILC) will use cold structures for the main linac. It is shown that a dc-biased polarized photoelectron source such as successfully used for the SLC can meet the charge requirements for the ILC micropulse with a polarization approaching 90%
LIONs at the Stanford Linear Accelerator Center
Constant, T.N.; Zdarko, R.W.; Simmons, R.H.; Bennett, B.M.
1998-01-01
The term LION is an acronym for Long Ionization Chamber. This is a distributed ion chamber which is used to monitor secondary ionization along the shield walls of a beam line resulting from incorrectly steered charged particle beams in lieu of the use of many discrete ion chambers. A cone of ionizing radiation emanating from a point source as a result of incorrect steering intercepts a portion of 1-5/8 inch Heliax cable (about 100 meters in length) filled with Argon gas at 20 psi and induces a pulsed current which is proportional to the ionizing charge. This signal is transmitted via the cable to an integrator circuit whose output is directed to an electronic comparators, which in turn is used to turn off the accelerated primary beam when preset limits are exceeded. This device is used in the Stanford Linear Accelerator Center (SLAC) Beam Containment System (BCS) to prevent potentially hazardous ionizing radiation resulting from incorrectly steered beams in areas that might be occupied by people. This paper describes the design parameters and experience in use in the Final Focus Test Beam (FFTB) area of the Stanford Linear Accelerator Center
Design of a linear neutron source
Buzarbaruah, N.; Dutta, N.J.; Bhardwaz, J.K.; Mohanty, S.R.
2015-01-01
Highlights: • This paper reports the design of a linear neutron source based on inertial electrostatic confinement fusion scheme. • The voltage and current that is to be applied to the grid is computed theoretically. • Neutron production rate is theoretically estimated and found to be of the order of 10 7 –10 8 neutrons/s. • Electric potential distribution and ion trajectories are studied using SIMION code. • Optimized condition for the inner grid transparency has been found out. - Abstract: In this paper, we present the design of a linear neutron source based on the concept of inertial electrostatic confinement fusion. The source mainly comprises of a concentric coaxial cylindrical grid assembly housed inside a double walled cylindrical vacuum chamber, a gas injection system, a high voltage feedthrough and a high voltage negative polarity power supply. The inner grid will be kept at a high negative potential with respect to the outer grid that will be grounded. The effect of grid transparency on electric potential distribution and ion trajectories has been studied using SIMION. A diffuse deuterium plasma will be initially created by making filament discharge and subsequently, on application of high negative voltage to the inner grid, deuterons will be accelerated towards the axis of the device. These deuterons will oscillate in the negative potential and consequently fuse in between the grids to produce neutrons. This source is expected to produce 10 7 –10 8 neutrons/s. The proposed linear neutron source will be operated both in the continuous and pulse modes and it will be utilized for a few near term applications namely fusion reactor material studies and explosive detection
Smart portable rehabilitation devices
Leahey Matt
2005-07-01
Full Text Available Abstract Background The majority of current portable orthotic devices and rehabilitative braces provide stability, apply precise pressure, or help maintain alignment of the joints with out the capability for real time monitoring of the patient's motions and forces and without the ability for real time adjustments of the applied forces and motions. Improved technology has allowed for advancements where these devices can be designed to apply a form of tension to resist motion of the joint. These devices induce quicker recovery and are more effective at restoring proper biomechanics and improving muscle function. However, their shortcoming is in their inability to be adjusted in real-time, which is the most ideal form of a device for rehabilitation. This introduces a second class of devices beyond passive orthotics. It is comprised of "active" or powered devices, and although more complicated in design, they are definitely the most versatile. An active or powered orthotic, usually employs some type of actuator(s. Methods In this paper we present several new advancements in the area of smart rehabilitation devices that have been developed by the Northeastern University Robotics and Mechatronics Laboratory. They are all compact, wearable and portable devices and boast re-programmable, real time computer controlled functions as the central theme behind their operation. The sensory information and computer control of the three described devices make for highly efficient and versatile systems that represent a whole new breed in wearable rehabilitation devices. Their applications range from active-assistive rehabilitation to resistance exercise and even have applications in gait training. The three devices described are: a transportable continuous passive motion elbow device, a wearable electro-rheological fluid based knee resistance device, and a wearable electrical stimulation and biofeedback knee device. Results Laboratory tests of the devices
Smart portable rehabilitation devices.
Mavroidis, Constantinos; Nikitczuk, Jason; Weinberg, Brian; Danaher, Gil; Jensen, Katherine; Pelletier, Philip; Prugnarola, Jennifer; Stuart, Ryan; Arango, Roberto; Leahey, Matt; Pavone, Robert; Provo, Andrew; Yasevac, Dan
2005-07-12
The majority of current portable orthotic devices and rehabilitative braces provide stability, apply precise pressure, or help maintain alignment of the joints with out the capability for real time monitoring of the patient's motions and forces and without the ability for real time adjustments of the applied forces and motions. Improved technology has allowed for advancements where these devices can be designed to apply a form of tension to resist motion of the joint. These devices induce quicker recovery and are more effective at restoring proper biomechanics and improving muscle function. However, their shortcoming is in their inability to be adjusted in real-time, which is the most ideal form of a device for rehabilitation. This introduces a second class of devices beyond passive orthotics. It is comprised of "active" or powered devices, and although more complicated in design, they are definitely the most versatile. An active or powered orthotic, usually employs some type of actuator(s). In this paper we present several new advancements in the area of smart rehabilitation devices that have been developed by the Northeastern University Robotics and Mechatronics Laboratory. They are all compact, wearable and portable devices and boast re-programmable, real time computer controlled functions as the central theme behind their operation. The sensory information and computer control of the three described devices make for highly efficient and versatile systems that represent a whole new breed in wearable rehabilitation devices. Their applications range from active-assistive rehabilitation to resistance exercise and even have applications in gait training. The three devices described are: a transportable continuous passive motion elbow device, a wearable electro-rheological fluid based knee resistance device, and a wearable electrical stimulation and biofeedback knee device. Laboratory tests of the devices demonstrated that they were able to meet their design
Topics in linear optical quantum computation
Glancy, Scott Charles
This thesis covers several topics in optical quantum computation. A quantum computer is a computational device which is able to manipulate information by performing unitary operations on some physical system whose state can be described as a vector (or mixture of vectors) in a Hilbert space. The basic unit of information, called the qubit, is considered to be a system with two orthogonal states, which are assigned logical values of 0 and 1. Photons make excellent candidates to serve as qubits. They have little interactions with the environment. Many operations can be performed using very simple linear optical devices such as beam splitters and phase shifters. Photons can easily be processed through circuit-like networks. Operations can be performed in very short times. Photons are ideally suited for the long-distance communication of quantum information. The great difficulty in constructing an optical quantum computer is that photons naturally interact weakly with one another. This thesis first gives a brief review of two early approaches to optical quantum computation. It will describe how any discrete unitary operation can be performed using a single photon and a network of beam splitters, and how the Kerr effect can be used to construct a two photon logic gate. Second, this work provides a thorough introduction to the linear optical quantum computer developed by Knill, Laflamme, and Milburn. It then presents this author's results on the reliability of this scheme when implemented using imperfect photon detectors. This author finds that quantum computers of this sort cannot be built using current technology. Third, this dissertation describes a method for constructing a linear optical quantum computer using nearly orthogonal coherent states of light as the qubits. It shows how a universal set of logic operations can be performed, including calculations of the fidelity with which these operations may be accomplished. It discusses methods for reducing and
Fluid circulation control device
Benard, Henri; Henocque, Jean.
1982-01-01
Horizontal fluid circulation control device, of the type having a pivoting flap. This device is intended for being fitted in the pipes of hydraulic installation, particularly in a bleed and venting system of a nuclear power station shifting radioactive or contaminated liquids. The characteristic of this device is the cut-out at the top of the flap to allow the air contained in the pipes to flow freely [fr
Mobile Device Encryption Systems
Teufl , Peter; Zefferer , Thomas; Stromberger , Christof
2013-01-01
Part 4: Software Security; International audience; The initially consumer oriented iOS and Android platforms, and the newly available Windows Phone 8 platform start to play an important role within business related areas. Within the business context, the devices are typically deployed via mobile device management (MDM) solutions, or within the bring-your-own-device (BYOD) context. In both scenarios, the security depends on many platform security functions, such as permission systems, manageme...
Production of linear polarization by segmentation of helical undulator
Tanaka, T.; Kitamura, H.
2002-01-01
A simple scheme to obtain linearly polarized radiation (LPR) with a segmented undulator is proposed. The undulator is composed of several segments each of which forms a helical undulator and has helicity opposite to those of adjacent segments. Due to coherent sum of radiation, the circularly polarized component is canceled out resulting in production of LPR without any higher harmonics. The radiation from the proposed device is investigated analytically, which shows that a high degree of linear polarization is obtained in spite of a finite beam emittance and angular acceptance of optics, if a sufficiently large number of segments and an adequate photon energy are chosen. Results of calculation to investigate practical performances of the proposed device are presented
Angus, J.P.; Salt, D.
1988-01-01
A temperature indicating device comprises a plurality of planar elements some undergoing a reversible change in appearance at a given temperature the remainder undergoing an irreversible change in appearance at a given temperature. The device is useful in indicating the temperature which an object has achieved as well as its actual temperature. The reversible change is produced by liquid crystal devices. The irreversible change is produced by an absorbent surface carrying substances e.g. waxes which melt at predetermined temperatures and are absorbed by the surface; alternatively paints may be used. The device is used for monitoring processes of encapsulation of radio active waste. (author)
Ibrahim, Yehia M.; Smith, Richard D.
2016-01-26
An ion trap device is disclosed. The device includes a series of electrodes that define an ion flow path. A radio frequency (RF) field is applied to the series of electrodes such that each electrode is phase shifted approximately 180 degrees from an adjacent electrode. A DC voltage is superimposed with the RF field to create a DC gradient to drive ions in the direction of the gradient. A second RF field or DC voltage is applied to selectively trap and release the ions from the device. Further, the device may be gridless and utilized at high pressure.