Flow Impedance in a Uniform Magnetically-Insulated Transmission Line

In two recent publications relativistic electron flow in cylindrical magnetically-insulated transmission lines (MITL) was analyzed and modeled under the assumption of negligible electron pressure. Cylindrical MITLs were used because of their common occurrence, and because they are the simplest case of finite width. The authors show in this report that the models apply equally to MITLs of any cross section

Status of magnetically-insulated power transmission theory

The theory of magnetically-insulated power flow has improved dramatically over the last two decades since the early works of Creedon, Lovelace and Ott, Ron, Mondelli, and Rostoker, and of Bergeron. During the intervening years theoretical improvements included a complete general kinetic theory that involved distributions of electrons based on quasi-conserved canonical variables and was used to study flow stability and to analyze simulations and pulsers with voltage adders. The status of theory at this time allowed them to understand many features of these flows, but did not allow detailed analysis for design and data interpretation. Recent theoretical advances have drastically changed this situation. Two recent static models based on layered flows have allowed them to understand and to improve power coupling in voltage adders, current adders, plasma opening switches and in systems where the vacuum impedance varies along the flow. A dynamic model based upon electrons flowing in one or more thin layers has permitted detailed self-consistent time-dependent calculations which include electron flow. This model accurately predicts experimental and simulational data

The KMOS Cluster Survey (KCS). I. The Fundamental Plane and the Formation Ages of Cluster Galaxies at Redshift 1.4 < Z < 1.6

We present the analysis of the fundamental plane (FP) for a sample of 19 massive red-sequence galaxies (${M}_{\star }\gt 4\times {10}^{10}$ ${M}_{\odot }$) in three known overdensities at $1.39\lt z\lt 1.61$ from the K-band Multi-object Spectrograph (KMOS) Cluster Survey, a guaranteed-time program with spectroscopy from the KMOS at the VLT and imaging from the Hubble Space Telescope. As expected, we find that the FP zero-point in B band evolves with redshift, from the value 0.443 of Coma to −0.10 ± 0.09, −0.19 ± 0.05, and −0.29 ± 0.12 for our clusters at z = 1.39, z = 1.46, and z = 1.61, respectively. For the most massive galaxies ($\mathrm{log}{M}_{\star }/{M}_{\odot }\gt 11$) in our sample, we translate the FP zero-point evolution into a mass-to-light-ratio M/L evolution, finding ${\rm{\Delta }}\mathrm{log}M/{L}_{B}=(-0.46\pm 0.10)z$, ${\rm{\Delta }}\mathrm{log}M/{L}_{B}=(-0.52\pm 0.07)z$, to ${\rm{\Delta }}\mathrm{log}M/{L}_{B}=(-0.55\pm 0.10)z$, respectively. We assess the potential contribution of the galaxy structural and stellar velocity dispersion evolution to the evolution of the FP zero-point and find it to be ~6%–35% of the FP zero-point evolution. The rate of M/L evolution is consistent with galaxies evolving passively. Using single stellar population models, we find an average age of ${2.33}_{-0.51}^{+0.86}$ Gyr for the $\mathrm{log}{M}_{\star }/{M}_{\odot }\gt 11$ galaxies in our massive and virialized cluster at z = 1.39, ${1.59}_{-0.62}^{+1.40}$ Gyr in a massive but not virialized cluster at z = 1.46, and ${1.20}_{-0.47}^{+1.03}$ Gyr in a protocluster at z = 1.61. After accounting for the difference in the age of the universe between redshifts, the ages of the galaxies in the three overdensities are consistent within the errors, with possibly a weak suggestion that galaxies in the most evolved structure are older

Reproductive biology of Sclerodermus brevicornis, a European parasitoid developing on three species of invasive longhorn beetles

The reproductive performance of Sclerodermus brevicornis (Kieffer), a bethylid wasp native to Europe, was evaluated on three species of facticious hosts. These are longhorn beetles which have recently invaded Europe from Asia: Anoplophora glabripennis (Motschulsky), Anoplophora chinensis (Forster) and Psacothea hilaris hilaris (Pascoe) (Coleoptera: Cerambycidae). Sclerodermus brevicornis attacked all three species, but offspring only developed to maturity on medium and large sized host larvae. Host species influenced the duration of parasitoid development and the number of offspring maturing, both were greatest on A. glabripennis, with up to 373 adult parasitoids emerging from a single host. The sex ratios of S. brevicornis broods were strongly female biased (ca. 9% males). We conclude that S. brevicornis has the potential to be efficiently mass-reared and actively deployed in the biological control of invasive longhorn beetles. Further progress should be encouraged by the successful use of other species of Sclerodermus against beetle pests in China

Segment-scale volcanic episodicity : evidence from the North Kolbeinsey Ridge, Atlantic

The upper oceanic crust is produced by magmatism at mid-ocean ridges, a process thought to be characterized by cyclic bouts of intense magmatic activity, separated by periods when faulting accommodates most or even all of the plate motion. It is not known whether there is a distinct periodicity to such magmatic–tectonic cycles. Here we present high-resolution sidescan sonar data from the neovolcanic zone of the North Kolbeinsey Ridge, a shallow slow-spreading ridge where high glacial and steady post-glacial sedimentation rates allow relative flow ages to be determined with a resolution of around 2 kyr using backscatter amplitude as a proxy for sediment thickness and hence age. We identify 18 lava flow fields covering 40% of the area surveyed. A group of 7 flow fields showing the highest (and similar) backscatter intensity are scattered along 75 km of axial valley surveyed, suggesting that at least this length of the segment was magmatically active within a 1.2 kyr time window. Based on conservative age estimates for all datable flows and estimated eruption volumes, the post-glacial volcanic activity imaged is insufficient to maintain crustal thickness, implying that episode(s) of enhanced activity must have preceded the volcanism we image

Diagnosing light ion beam diodes

This lecture begins with a discussion of diagnostics in ion-beam diodes. This will include electromagnetic measurements, measurements of the electron cloud, and measurements of anode plasmas. A few minutes will be spent on diagnostics of distributed ion sources required for one class of ion diodes, the plasma-filled versions, which require high-density, highly ionized sources of very uniform plasma. The measurements of the beam characteristics will then be discussed. This will be broken into two regions; the region near the diode where diagnostics are generally extensions of those used in other fields; and the region near focus where new diagnostics have been developed

Diagnosing ion-beam targets, data acquisition, reactor conditions

The final lecture will discuss diagnostics of the target. These are very difficult because of the short times, small spatial extent, and extreme values of temperature and pressure. Diagnostics for temperature, density profile, and neutron production will be discussed. A few minutes will be devoted to data acquisition needs. The lecture will end with a discussion of current areas where improvements are needed and future diagnostics that will be required for reactor conditions