Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Alfvén ion–ion hybrid wave heating in the Phaedrus-T tokamak (1996)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 3 (1996), S. 1331-1339 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In the Phaedrus-T tokamak [R. A. Breun et al., Fusion Technol. 19, 1327 (1991)], Alfvén waves are indirectly driven by a fast wave antenna array. Small fractions of minority ions are shown to have a large effect on the Alfvén spectrum, as measured at the edge. An ion–ion hybrid Alfvén mode has been identified by measuring dispersion properties. Landau damping is predicted to be large and spatially localized. These Alfvénic waves are experimentally shown to generate correlated electron heating and changes in density near the core of the tokamak plasma. Fast wave antenna fields can mode convert at a hybrid Alfvén resonance and provide a promising route to spatially localized tokamak heating and current drive, even for low effective ionic charge Zeff≈1.3–2. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871786
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Alfvén wave current drive in the Phaedrus-T tokamak (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 2263-2271 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The first experimental evidence of Alfvén Wave Current Drive (AWCD) in a tokamak is shown. In a low-density experiment, an estimated 20–35 kA out of 65 kA total current, or 30%–55% of the total current has been driven. The estimated efficiency for current driven per unit RF input power is approximately ICD/PRF≈0.2 A/W, which is near the predicted efficiency, and corresponds to the commonly used figure of merit, neR0ICD/PRF≈0.4×1018 A m−2 W−1, where ne is plasma density and R0 is the major radius. The significant 30%–40% drop in loop voltage observed cannot be explained by any plausible increase in electron temperature Te, or decrease in inductive plasma energy, or changes in plasma resistivity. Independently measured loop voltage, Te, effective ionic charge Zeff, and plasma inductance and resistance are all consistent with this conclusion. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871249
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Alfvén wave experiments in the Phaedrus-T tokamakf| (1993)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 5 (1993), S. 2506-2512 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Heating in the Alfvén resonant regime has been demonstrated in the Phaedrus-T tokamak [Fusion Technol. 19, 1327 (1991)]. Electron heating during injection of radio-frequency (rf) power is indicated by a 30%–40% drop in loop voltage and modifications in sawtooth activity. Heating was observed at a frequency ωrf≈0.7Ωi on axis, using a two-strap fast wave antenna operated at 7 and 9.2 MHz with 180° phasing (N(parallel)∼100). Numerical modeling with the fast wave code fastwa [Plasma Phys. Controlled Fusion 33, 417 (1991)] indicates that for Phaedrus-T parameters the kinetic Alfvén wave is excited via mode conversion from a surface fast wave at the Alfvén resonance and is subsequently damped on electrons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860736
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Toroidally linked mirrors (1985)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 28 (1985), S. 3594-3597 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mirrors linked by toroidal segments may be stabilized by ponderomotive force produced by electromagnetic waves at the ion-cyclotron frequency. This may provide a simple alternative to tandem mirrors and bumpy tori. Approximate calculations of equilibrium, stability, and diffusion are given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.865315
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Experimental simulation of a gaseous plasma collector (1990)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 2 (1990), S. 837-841 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Hydrogen plasma with a density of 3×1014 cm−3 and electron temperature of 20 eV is injected parallel to a 0.1 T B field, into hydrogen (and helium) neutral gas at 0.1–2 Torr. This plasma is opaque to molecular hydrogen but transparent to Franck–Condon neutrals. The axial density and temperature scale length increased with decreasing gas pressure but were insensitive to plasma density and axial magnetic field strength. The plasma decay is explained by radial ion diffusion resulting from collisions with fast neutrals while the fast neutral density is determined by the radial pressure balance between fast neutrals and the cold background gas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.859269
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Experimental simulation of a gaseous divertor: Measurements of neutral density inside the plasma (1991)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 3 (1991), S. 834-837 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Direct measurements of the neutral density in the core of hydrogen plasma with a density of 3–4×1014 cm−3 and electron temperature of 15–20 eV in a magnetic field of 0.2 T, injected into hydrogen neutral gas at a pressure of 0.1–2 Torr are performed with plasma emission spectroscopy. The data are in agreement with the results of measured plasma decay [Phys. Fluids B 2, 837 (1990)] and can be explained by radial pressure balance between fast neutrals inside the plasma and cold background gas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.859878
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Nanosecond spark calibrator for Thomson scattering system (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 4621-4624 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A nanosecond spark system has been built for spectral calibration of a Thomson scattering system based on a ruby laser–MCP detector system. The fast calibration source has the advantage that its pulse duration and signal amplitude are similar to the signal collected in the electron temperature measurements. In the spark system, the duration of the light pulse (30 ns) is determined by the shock-wave expansion of the spark plasma. The light source is very bright due to the high plasma pressure prior to expansion. The calibrator uses an auxiliary spark for preionization to achieve good reproducibility and low jitter. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1145299
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Specification and analysis of self-timed circuits (1994)
    Springer
    The journal of VLSI signal processing systems for signal, image, and video technology 7 (1994), S. 117-135 
    Details
    ISSN: 1573-109X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The problems of self-timed behavior specification and verification are considered on the basis of an event model—Change Diagram (CD). The descriptive power of a CD model is demonstrated by comparing the CD with Signal Transition Graphs (STG). CD differs from STG by two types of causal relations (AND and OR) between events (in STG only AND-relation is presented). CD verification is shown to be reducible to an analysis of precedence and concurrency properties for events. These properties are hard to analyze directly by a cyclic CD. We suggest that the cyclic description be replaced by an equivalent acyclic one (called an unfolding) in order to solve the analysis problem. The notion of CD correctness is introduced, and the necessity and sufficiency of this notion for the implementation to be in self-timed class are shown. The polynomial algorithms for CD correctness verification are considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02108193
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Deadlock prevention using Petri nets and their unfoldings (1998)
    Springer
    The international journal of advanced manufacturing technology 14 (1998), S. 750-759 
    Details
    ISSN: 1433-3015
    Keywords: Deadlock prevention ; Petri nets ; Unfoldings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Unfoldings of Petri nets (PN) provide a method for the analysis of concurrent systems without restoring the state space of a system. This allows one to overcome the “state explosion” problem. Many properties of the initial PN (boundedness, safety, persistency and hazards) can be checked by constructing the unfolding. A deadlock prevention procedure first detects deadlocks using an unfolding. Then, the first method reduces the unfolding to a set of deadlock-free subunfoldings that cover all live behaviours. The second method uses a direct transformation at the level of the original PN. The methods are implemented as subroutines in the Berkeley program SIS. Although the deadlock detection problem is known to be NP-complete, experimental results show that for highly parallel specifications deadlock prevention by unfoldings is typically more efficient than deadlock prevention based on symbolic BDD (binary decision diagrams) traversal of the corresponding reachability graph.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01438227
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Analysis and identification of speed-independent circuits on an event model (1994)
    Springer
    Formal methods in system design 4 (1994), S. 33-75 
    Details
    ISSN: 1572-8102
    Keywords: speed-independent circuits ; delay-insensitive circuits ; event models ; signal graph ; analysis ; identification ; verification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract The object of this article is the analysis of asynchronous circuits for speed independence or delay insensitivity. The circuits are specified as a netlist of logic functions describing the components. The analysis is based on a derivation of an event specification of the circuit behavior in a form of a signal graph. Signal graphs can be viewed either as a formalization of timing diagrams, or as a signal interpreted version of marked graphs (a subclass of Petri nets). The main advantage of this method is that a state explosion is avoided. A restoration of an event specification of a circuit also helps to solve the behavior identification problem, i.e., to compare the obtained specification with the desired specification. We illustrate the method by means of some examples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01383956
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...