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Seasonal litter fall and changes in dry weight and minerals within the litter layer were sampled throughout one year. The annual total litter fall was 4.9 t per hectare of which 70% was leaf fall. Litter fall was highest in spring and early summer, the falls of each component (leaf, wood, etc.) and species being markedly seasonal but not all in phase. The(More)
Shear Alfvén waves with transverse scales of electron skin-depth size are launched with a dual-disk antenna in the Large Plasma Device at UCLA. The waves are studied in the kinetic and inertial regimes. The kinetic shear Alfvén wave is observed for the first time and exhibits predicted radial structure. The perpendicular propagation of the wave is also(More)
Measurements of a magnetized plasma with a controlled electron temperature gradient show the development of a broadband spectrum of density and temperature fluctuations having an exponential frequency dependence at frequencies below the ion cyclotron frequency. The origin of the exponential frequency behavior is traced to temporal pulses of Lorentzian(More)
In 1991 a manuscript describing an instrument for studying magnetized plasmas was published in this journal. The Large Plasma Device (LAPD) was upgraded in 2001 and has become a national user facility for the study of basic plasma physics. The upgrade as well as diagnostics introduced since then has significantly changed the capabilities of the device. All(More)
Two adjacent coastal ecosystems, dry sclerophyll scrub and introduced grassland, were sampled two (grassland) or three (scrub) times throughout one year to estimate total and component dry matter and mineral contents. The soil was the major mineral pool in both ecosystems and contained at least 60% of all minerals except potassium. The scrub live plus dead(More)
Pulses having a temporal Lorentzian shape arise naturally from topological changes in flow trajectories or phase-space orbits associated with deterministic chaos. The pulses can appear as random intermittent events in the time series of observable quantities, and they are the cause of exponential frequency power spectra previously observed in magnetically(More)
The dynamics of transport at the edge of magnetized plasmas is deterministic chaos. The connection is made by a previous survey [M. A. Pedrosa et al., Phys. Rev. Lett. 82, 3621 (1999)] of measurements of fluctuations that is shown to exhibit power spectra with exponential frequency dependence over a broad range, which is the signature of deterministic(More)
Continuous control over azimuthal flow and shear in the edge of the Large Plasma Device (LAPD) has been achieved using a biasable limiter which has allowed a careful study of the effect of flow shear on pressure-gradient-driven turbulence and transport in the LAPD. The LAPD rotates spontaneously in the ion diamagnetic direction; positive limiter bias first(More)
This experiment illustrates the spatio-temporal pattern of the uctuations that spontaneously develop in a magnetized temperature lament whose transverse scale is comparable to the electron skin-depth. A high-frequency mode exhibits a striking spiral structure and is identi ed as a drift-Alfv en eigenmode. A low frequency mode is found to be localized near(More)
Azimuthal flow is driven in the edge of the Large Plasma Device LAPD W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 1991 through biasing a section of the vacuum vessel relative to the plasma source cathode. As the applied bias exceeds a threshold, a transition in radial particle confinement is observed, evidenced by a dramatic steepening in the density(More)