The Linac Coherent Light Source (LCLS) is an x-ray free-electron laser (FEL) project based on the SLAC linac. The LCLS Photoinjector beamline has been designed to deliver 10-ps long electron bunches of 1 nC with a normalized projected transverse emittance smaller than 1.2 mm-mrad at 135 MeV. Tolerances and regulation requirements are tight for this tuning. Half of the total emittance at the end of the injector comes from the ''cathode emittance'' which is 0.7 mm-mrad for our nominal 1nC tuning. As the ''cathode emittance'' scales linearly with laser spot radius, the emittance will be dramatically reduced for smaller radius, but this is only possible at lower charge. In particular, for a 0.2 nC charge, we believe we can achieve an emittance closer to 0.4 mm-mrad. This working point will be easier to tune and the beam quality should be much easier to maintain than for the 1 nC case. In the second half of this paper, we discuss optimum laser pulse shapes. We demonstrate that the benefits of the ellipsoidal shapes seem to be important enough so that serious investigations should be carried out in the production of such pulses.

The SURIYA project at the Fast Neutron Research Facility (FNRF) has been established and is being commissioning to generate femtosecond (fs) electron bunches. Theses short bunches are produced by a system consisting of an S-band thermionic cathode RF-gun, an alpha magnet (a-magnet) serving as a magnetic bunch compressor, and a SLAC-type linear accelerator (linac). The characteristics of its major components and the beam characterizations as well as the preliminary experimental results will be presented and discussed in this paper.

Article discussing research on the correlation consistent composite approach (ccCA) and an alternative to the Gaussian-n methods.

Two spectrometers have been added to the LCLS photoinjector beamline. The first one will be located close to the exit of the Photoinjector RF gun. With this diagnostic, we will measure beam energy, energy spread (correlated and uncorrelated), possibly deleterious structure in the longitudinal phase space induced by longitudinal space charge force, and slice thermal emittance ... This extensive characterization of the 5MeV electron bunch will be made possible by combining this spectrometer with other diagnostics (YAG screens and Cerenkov Radiator). A second spectrometer located at the end of the beamline has been designed to characterize the 6 dimensional phase space of the 135MeV beam to be injected in the main accelerator. At that second spectrometer station, we will measure energy, energy spread (correlated and uncorrelated), longitudinal phase space, slice emittances ... Those last two measurements require using this spectrometer in combination with the transverse RF deflecting cavity and with the quadrupole scan emittance station. The designs of these two spectrometers have been supported by simulations from MAD and PARMELA.

{sup 99}Tc and {sup 129}I are important contributors to risk assessment due to their long half-lives and high mobility as aqueous anionic species. We analyzed {sup 99}Tc and {sup 129}I in groundwater samples in and near 11 underground nuclear tests and in melt glass and rock samples retrieved from the Chancellor test cavity, Nevada Test Site. The {sup 129}I/{sup 127}I ratio ranges from 10{sup -3} to 10{sup -6} in cavity water and 10{sup -4} to 10{sup -9} in satellite wells. The {sup 99}Tc concentration ranges from 3 to 10{sup -4} Bq/L in cavity waters and from 0.3 to 10{sup -4} Bq/L in satellite wells. Downstream migration is apparent for both radionuclides. However, it is affected by both retardation and initial distribution. In-situ {sup 99}Tc and {sup 129}I K{sub d}s calculated using rubble and water concentrations are 3 to 22 mL/g and 0 to 0.12 mL/g, respectively and are suggestive of mildly reducing conditions. {sup 129}I distribution in the melt glass, rubble and groundwater of the Chancellor test cavity is 28%, 24% and 48%, respectively; for {sup 99}Tc, it is 65%, 35% and 0.3%, respectively. Our partitioning estimates differ from those of underground tests in French Polynesia, implying that fission product …

Centrosomes nucleate and organize interphase MTs and areinstrumental in the assembly of the mitotic bipolar spindle. Here wereport that two members of the multifunctional protein 4.1 family havedistinct distributions at centrosomes. Protein 4.1R localizes to maturecentrioles whereas 4.1G is a component of the pericentriolar matrixsurrounding centrioles. To selectively probe 4.1R function, we used RNAinterference-mediated depletion of 4.1R without decreasing 4.1Gexpression. 4.1R downregulation reduces MT anchoring and organization atinterphase and impairs centrosome separation during prometaphase.Metaphase chromosomes fail to properly condense/align and spindleorganization is aberrant. Notably 4.1R depletion causes mislocalizationof its binding partner NuMA (Nuclear Mitotic Apparatus Protein),essential for spindle pole focusing, and disrupts ninein. Duringanaphase/telophase, 4.1R-depleted cells have lagging chromosomes andaberrant MT bridges. Our data provide functional evidence that 4.1R makescrucial contributions to centrosome integrity and to mitotic spindlestructure enabling mitosis and anaphase to proceed with the coordinatedprecision required to avoid pathological events.

Femtosecond (fs) electron and photon pulses become a tool of increasing importance to study dynamics in ultrafast processes. Such short electron pulses can be generated from a system consisting of a thermionic-cathode RF-gun and a magnetic bunch compressor. The fs electron pulses can be used directly or used as a source to produce equally short electromagnetic radiation pulses via certain kind of radiation production processes. At the Fast Neutron Research Facility (FNRF), Thailand, we are especially interested in production of radiation in Farinfrared and X-ray regime. In the far-infrared wavelengths, the radiation emitted from fs electron pulses is emitted coherently resulting high intensity radiation. In the X-ray regime, development of fs X-ray sources is crucial for application in ultrafast sciene.

The work contained herein constitutes a report of the ''Beyond the Standard Model'' working group for the Workshop ''Physics at TeV Colliders'', Les Houches, France, 2-20 May, 2005. We present reviews of current topics as well as original research carried out for the workshop. Supersymmetric and non-supersymmetric models are studied, as well as computational tools designed in order to facilitate their phenomenology.

The Linac Coherent Light Source (LCLS) Free-Electron Laser will operate in the wavelength range of 1.5 to 15 Angstroms. Energy loss due to wakefields within the long undulator can degrade the FEL process by detuning the resonant FEL frequency. The wakefields arise from the vacuum chamber wall resistivity, its surface roughness, and abrupt changes in its aperture. For LCLS parameters, the resistive component is the most critical and depends upon the chamber material (e.g. Cu) and its radius. To study the expected performance in the presence of these wakefields, we make a series of start-to-end simulations with tracking codes PARMELA and ELEGANT and time-dependent FEL simulation codes Genesis 1.3 and Ginger. We discuss the impact of the wakefield on output energy, spectral bandwidth, and temporal envelope of the output FEL pulse, as well as the benefits of a partial compensation obtained with a slight z dependent taper in the undulator field. We compare these results to those obtained by decreasing the bunch charge or increasing the vacuum chamber radius. We also compare our results to those predicted in concurrent analytical work.

The central metabolic fluxes of Shewanella oneidensis MR-1were examined under carbon-limited (aerobic) and oxygen-limited(micro-aerobic) chemostat conditions using 13C labeled lactate as thesole carbon source. The carbon labeling patterns of key amino acids inbiomass were probed using both GC-MS and 13C-NMR. Based on the genomeannotation, a metabolic pathway model was constructed to quantify thecentral metabolic flux distributions. The model showed that thetricarboxylic acid (TCA) cycle is the major carbon metabolism route underboth conditions. The Entner-Doudoroff and pentose phosphate pathways weremainly utilized for biomass synthesis (flux below 5 percent of thelactate uptake rate). The anapleurotic reactions (pyruvate to malate andoxaloacetate to phosphoenolpyruvate) and the glyoxylate shunt wereactive. Under carbon-limited conditions, a substantial amount of carbonwas oxidized via the highly reversible serine metabolic pathway. Fluxesthrough the TCA cycle were less whereas acetate production was more underoxygen limitation than under carbon limitation. Although fluxdistributions under aerobic, micro-aerobic, and shake-flask cultureconditions were dramatically different, the relative flux ratios of thecentral metabolic reactions did not vary significantly. Hence, S.oneidensis metabolism appears to be quite robust to environmentalchanges. Our study also demonstrates the merit of coupling GC-MS with 13CNMR for metabolic flux analysis to reduce the use of 13C labeledsubstrates and to obtain more accurate flux values.

A basic problem in gravitational physics is the resolution of spacetime singularities where general relativity breaks down. The simplest such singularities are conical singularities arising from orbifold identifications of flat space, and the most challenging are spacelike singularities inside black holes (and in cosmology). Topology changing processes also require evolution through classically singular spacetimes. I briefly review how a phase of closed string tachyon condensate replaces, and helps to resolve, basic singularities of each of these types. Finally I discuss some interesting features of singularities arising in the small volume limit of compact negatively curved spaces and the emerging zoology of spacelike singularities.

Gradient direction matching (GDM) is the main target identification algorithm used in the Image Content Engine project at Lawrence Livermore National Laboratory. GDM is a 3D solid model-based edge-matching algorithm which does not require explicit edge extraction from the source image. The GDM algorithm is presented, identifying areas where performance enhancement seems possible. Improving the process of producing model gradient directions from the solid model by assigning different weights to different parts of the model is an extension tested in the current study. Given a simple geometric model, we attempt to determine, without obvious semantic clues, if different weight values produce significantly better matching accuracy, and how those weights should be assigned to produce the best matching accuracy. Two simple candidate strategies for assigning weights are proposed--pixel-weighted and edge-weighted. We adjust the weights of the components in a simple model of a tractor/semi-trailer using relevance feedback to produce an optimal set of weights for this model and a particular test image. The optimal weights are then compared with pixel and edge-weighting strategies to determine which is most suitable and under what circumstances.