Exploring minimal scenarios to produce transversely bright electron beams using the eigen-emittance concept

Next generation hard X-ray free electron lasers require electron beams with low transverse emittance. One proposal to achieve these low emittances is to exploit the eigen-emittance values of the beam. The eigen-emittances are invariant under linear beam transport and equivalent to the emittances in an uncorrelated beam. If a correlated beam with two small eigen-emittances can be produced, removal of the correlations via appropriate optics will lead to two small emittance values, provided non-linear effects are not too large. We study how such a beam may be produced using minimal linear correlations. We find it is theoretically possible to produce such a beam, however, it may be more difficult to realize in practice. We identify linear correlations that may lead to physically realizable emittance schemes and discuss promising future avenues.     

Human and rat primary C-fibre afferents store and release secretoneurin, a novel neuropeptide

Secretoneurin is a recently discovered neuropeptide derived from secretogranin II (SgII). Since this peptide could be detected in the dorsal horn of the spinal cord we studied whether it is localized in and released from primary afferent neurons. Secretoneurin was investigated with immunocytochemistry and radioimmunoassay in spinal cord, dorsal root ganglia and peripheral organs. SgII mRNA was determined in dorsal root ganglia. Normal rats and rats pre-treated neonatally with capsaicin to destroy selectively polymodal nociceptive (C-) fibres were used. Slices of dorsal spinal cord were perfused in vitro for release experiments. Immunocytochemistry showed a distinct distribution of secretoneurin-immunoreactivity (IR) in the spinal cord and, lower brainstem. A particularly high density of fibres was found in lamina I and outer lamina II of the caudal trigeminal nucleus and of the spinal cord. This distribution was qualitatively identical in rat and human post-mortem tissue. Numerous small diameter and some large dorsal root ganglia neurons were found to contain SgII mRNA. Capsaicin treatment led to a marked depletion of secretoneurin-IR in the substantia gelatinosa, but not in other immunopositive areas of the spinal cord and to a substantial loss of small (< 25 microns) SgII-mRNA-containing dorsal root ganglia neurons. Radioimmunoassay revealed a significant decrease of secretoneurin-IR in the dorsal spinal cord, the trachea, heart and urinary bladder of capsaicin-treated rats. Perfusion of spinal cord slices with capsaicin as well as with 60 mM potassium led to a release of secretoneurin-IR. In conclusion, secretoneurin is a neuropeptide which is stored in and released from capsaicin-sensitive, primary afferent (C-fibre) neurons.(ABSTRACT TRUNCATED AT 250 WORDS)     

Performance potential of silicon bipolar transistors

The performance potential of silicon bipolar transistors is investigated by device simulation. Using a one-dimensional drift-diffusion equation solver, the SPICE parameters of self-aligned transistors are extracted from doping profiles and device geometries. These parameters are used to predict the CML gate delay for different doping profiles. The validity of this extraction procedure is verified by comparison with experimental data. For a double-diffusion type doping profile with a pinch resistance of 15 k Omega / Square Operator , a transit frequency of 56 GHz and a CML gate delay of approximately 15 ps are achievable. With a doping profile including a low-doped emitter region and a high base doping concentration, significant improvements are found: A transit frequency of 81.6 GHz and a pinch resistance of 10 k Omega / Square Operator enable CML gate delay times below 10 ps.<>     

Diagnosing pure-electron plasmas with internal particle flux probes

Techniques for measuring local plasma potential, density, and temperature of pure-electron plasmas using emissive and Langmuir probes are described. The plasma potential is measured as the least negative potential at which a hot tungsten filament emits electrons. Temperature is measured, as is commonly done in quasineutral plasmas, through the interpretation of a Langmuir probe current-voltage characteristic. Due to the lack of ion-saturation current, the density must also be measured through the interpretation of this characteristic thereby greatly complicating the measurement. Measurements are further complicated by low densities, low cross field transport rates, and large flows typical of pure-electron plasmas. This article describes the use of these techniques on pure-electron plasmas in the Columbia Non-neutral Torus (CNT) stellarator. Measured values for present baseline experimental parameters in CNT are phi(p)=-200+/-2 V, T(e)=4+/-1 eV, and n(e) on the order of 10(12) m(-3) in the interior.     

Listening, not watching: Situational familiarity and the ability to detect deception.

In 4 experiments, the authors investigated the influence of situational familiarity with the judgmental context on the process of lie detection. They predicted that high familiarity with a situation leads to a more pronounced use of content cues when making judgments of veracity. Therefore, they expected higher classification accuracy of truths and lies under high familiarity. Under low situational familiarity, they expected that people achieve lower accuracy rates because they use more nonverbal cues for their veracity judgments. In all 4 experiments, participants with high situational familiarity achieved higher accuracy rates in classifying both truthful and deceptive messages than participants with low situational familiarity. Moreover, mediational analyses demonstrated that higher classification accuracy in the high-familiarity condition was associated with more use of verbal content cues and less use of nonverbal cues. (PsycINFO Database Record (c) 2011 APA, all rights reserved)