The Conference was well-attended with 100 participants (attendees list included). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. The formal schedule and speaker program and the poster program is given. In addition to these formal interactions, 'free time' was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.

The Report is Gordon Research Conferences Laser Interaction with materials.

Article about an event held to celebrate 30 years of Zachary Scott Theatre's children's educational program, Project Interact.

The Stanford Linear Accelerator Center is evaluating the feasibility of placing a free electron laser (FEL) at the end of the linear accelerator. The proposal is to inject electrons two thirds of the way down the linac, accelerate the electrons for the last one third of the linac, and then send the electrons into the FEL. This project is known as the LCLS (Linac Coherent Light Source). To test the feasibility of the LCLS, a smaller experiment VISA (Visual to Infrared SASE (Self Amplified Stimulated Emission) Amplifier) is being performed at Brookhaven National Laboratory. VISA consists of four wiggler segments, each 0.99 m long. The four segments are required to be aligned to the beam axis with an rms error less than 50 {micro}m [1]. This very demanding alignment is carried out in two steps [2]. First the segments are fiducialized using a pulsed wire system. Then the wiggler segments are placed along a reference laser beam which coincides with the electron beam axis. In the wiggler segment fiducialization, a wire is stretched through a wiggler segment and a current pulse is sent down the wire. The deflection of the wire is monitored. The deflection gives information about the electron …

Presently, the demand for high quality synchrotron radiation is increasing all over the world. One of the fascinating aspects of this novel tool is the broad range of scientific users interested in synchrotron radiation. They come from physics, chemistry, biology, and medicine, to name just a few. Third generation storage which recently became available for users will by far not be able to satisfy all the beam-time requests. In addition, it is also recognized that long-term scientific efficiency and technological success is heavily dependent on ease of access to a home based facility nearby and continuing fine-tuning of all components of a beam line. Based on the high quality user community in Switzerland and their prospective research activities, the Paul Scherrer Institute, in close collaboration with interested research groups from the Swiss universities and the Swiss Federal Institutes of Technology, has worked out a proposal to build an advanced synchrotron light source in Switzerland, which will come into operation in the year 2001. It has been named SLS as acronym for Swiss Light Source.

Regulation of bacterial spore solvent and solute permeability is a fundamental feature of dormancy but is poorly understood. Here we present a new technique, nano-scale secondary ion mass spectrometry (NanoSIMS) that allows the direct visualization and quantification of chemical gradients within spores. Using NanoSIMS, we demonstrate the penetration of water and a simple ionic salt, LiF, into the core of Bacillus thuringiensis israelensis (Bti) spores. The results demonstrate chemical gradients spanning the outer coat to the inner spore core that are driven by concentration-dependent ionic fluxes. Using deuterated water (D{sub 2}O), we have shown that external water is either retained or exchanged with water contained within the spore. Hydration and exchange are rapid, on a timescale of < 1 minute. Our results suggest a permeation mechanism by which short-time scale diffusion into and out of the spore can occur along hydration pathways. Additional studies are in progress to define the flux rates and mechanisms controlling these processes.

Accurately modeling and predicting performance for large-scale applications becomes increasingly difficult as system complexity scales dramatically. Analytic predictive models are useful, but are difficult to construct, usually limited in scope, and often fail to capture subtle interactions between architecture and software. In contrast, we employ multilayer neural networks trained on input data from executions on the target platform. This approach is useful for predicting many aspects of performance, and it captures full system complexity. Our models are developed automatically from the training input set, avoiding the difficult and potentially error-prone process required to develop analytic models. This study focuses on the high-performance, parallel application SMG2000, a much studied code whose variations in execution times are still not well understood. Our model predicts performance on two large-scale parallel platforms within 5%-7% error across a large, multi-dimensional parameter space.

The NLC Test Accelerator (NLCTA) at SLAC was built to address various beam dynamics issues for the Next Linear Collider. An S-Band RF gun is being installed together with a large-angle extraction line at 60 MeV followed by a matching section, buncher and final focus for the laser acceleration experiment, E163. The laser-electron interaction area is followed by a broad range, high resolution spectrometer (HES) for electron bunch analysis. Another spectrometer at 6 MeV will be used for analysis of bunch charges up to 1 nC. Emittance compensating solenoids and the low energy spectrometer (LES) will be used to tune for best operating point and match to the linac. Optical symmetries in the design of the 25.5{sup o} extraction line provide 1:1 phase space transfer without use of sextupoles for a large, 6D phase space volume and range of input conditions. Design techniques, tolerances, tuning sensitivities and orthogonal knobs are discussed.

The Next and Global Linear Collider (NLC/GLC) designs require precision alignment of the beam in the accelerator structures to reduce short range wakefields. The moderately damped and detuned structures themselves provide suitable higher order mode (HOM) signals to measure this alignment. The modes in the lowest dipole band, whose frequencies range from 14-16 GHz, provide the strongest signals. To determine the position resolution they provide, an NLC/GLC prototype structure that was installed in the ASSET facility of the SLAC Linac was instrumented to downmix and digitize these signals. The beam position within the structure was determined by simultaneously measuring the signals at three frequencies (14.3, 15, 15.7 GHz) corresponding to modes localized at the beginning, the middle and the end of the 60 cm long structure. A resolution of 1 micron was achieved even with 28 dB signal attenuation, which is better than the 5 micron resolution required for the NLC/GLC.

Encyclopedia article in the 'International Encyclopedia of Economic Sociology' discussing health care, globalization and health, and the effect of the economy on the structure of the health care system.

Despite decades of progress in quantum mechanics, electron correlation effects are still only partially understood. Experiments in which both electrons are ejected from an oriented hydrogen molecule by absorption of a single photon have recently demonstrated a puzzling phenomenon: The ejection pattern of the electrons depends sensitively on the bond distance between the two nuclei as they vibrate in their ground state. Here we report a complete numerical solution of the Schrodinger equation for the double photoionization of H2. The results suggest that the distribution of photoelectrons emitted from aligned molecules reflects electron correlation effects that are purely molecular in origin.

The consistency of different instruments and methods for measuring two-dimensional (2D) power spectral density (PSD) distributions are investigated. The instruments are an interferometric microscope, an atomic force microscope (AFM) and the X-ray Reflectivity and Scattering experimental facility, all available at Lawrence Berkeley National Laboratory. The measurements were performed with a gold-coated mirror with a highly polished stainless steel substrate. It was shown that these three techniques provide essentially consistent results. For the stainless steel mirror, an envelope over all measured PSD distributions can be described with an inverse power-law PSD function. It is also shown that the measurements can be corrected for the specific spatial frequency dependent systematic errors of the instruments. The AFM and the X-ray scattering measurements were used to determine the modulation transfer function of the interferometric microscope. The corresponding correction procedure is discussed in detail. Lower frequency investigation of the 2D PSD distribution was also performed with a long trace profiler and a ZYGO GPI interferometer. These measurements are in some contradiction, suggesting that the reliability of the measurements has to be confirmed with additional investigation. Based on the crosscheck of the performance of all used methods, we discuss the ways for improving the 2D PSD …

We have used the unique spatial sensitivity of polarized neutron and soft x-ray beams in reflection geometry to measure the depth dependence of magnetization across the interface between a ferromagnet and antiferromagnet. The new uncompensated magnetization near the interface responds to applied field, while the uncompensated spins in the antiferromagnetic bulk are pinned, thus providing a means to establish exchange bias.

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Article discussing the development of the University of North Texas (UNT) Libraries' Portal to Texas History.

We report the observation of Debye-Scherrer diffraction using electron pulses emitted from a fs-laser plasma. Titanium sapphire laser pulses with 1.6 mJ/45 fs at 1 kHz are focused on a moving steel tape at close to normal incidence. The laser plasma generated ejects a large number of electrons in the direction of polarization, with a continuous energy spectrum extending up to 100 keV. Selecting an energy range of these electrons and scattering them on a thin aluminium sample generates a ''streaked'' diffraction pattern with unique features.

Liquid silica at high pressure and temperature is shown to undergo significant structural modifications and profound changes in its electronic properties. Temperature measurements on shock waves in silica at 70-1000 GPa indicate that the specific heat of liquid SiO{sub 2} rises well above the Dulong-Petit limit, exhibiting a broad peak with temperature that is attributable to the growing structural disorder caused by bond-breaking in the melt. The simultaneous sharp rise in optical reflectivity of liquid SiO{sub 2} indicates that dissociation causes the electrical and therefore thermal conductivities of silica to attain metallic-like values of 1-5 x 10{sup 5} S/m and 24-600 W/m.K respectively.

Monocrystalline copper samples with orientations of [001] and [221] were shocked at pressures ranging from 20 GPa to 60 GPa using two techniques: direct drive lasers and explosively driven flyer plates. The pulse duration for these techniques differed substantially: 2 ns for the laser experiments and 1.1-1.4 {micro}s for the flyer-plate experiments. The residual microstructures were dependent on orientation, pressure, and shocking method. The much shorter pulse duration in laser shock yielded recovery microstructures with no or limited dislocation motion. For the flyer-plate experiments, the longer pulse duration allow shock-generated defects to reorganize into lower energy configurations. Calculations show that the post shock cooling occurs in a time scale of 0.2 s for laser shock and 1000 s for plate-impact shock, propitiating recovery and recrystallization conditions for the latter. At the higher pressure level extensive recrystallization was observed in the plate-impact samples, while it was absent in laser shock. An effect that is proposed to contribute significantly to the formation of recrystallized regions is the existence of micro-shearbands, which increase the local temperature.

Two-dimensional simulations with the BZOHAR [B.I. Cohen, B.F. Lasinski, A.B. Langdon, and E.A. Williams, Phys. Plasmas 4, 956 (1997)] hybrid code (kinetic particle ions and Boltzmann fluid electrons) have been used to investigate the saturation of stimulated Brillouin backscatter (SBBS) instability including the effects of ion-ion collisions and inhomogeneity. Ion-ion collisions tend to increase ion-wave dissipation, which decreases the gain exponent for stimulated Brillouin backscattering; and the peak Brillouin backscatter reflectivities tend to decrease with increasing collisionality in the simulations. Two types of Langevin-operator, ion-ion collision models were implemented in the simulations. In both models used the collisions are functions of the local ion temperature and density, but the collisions have no velocity dependence in the first model. In the second model, the collisions are also functions of the energy of the ion that is being scattered so as to represent a Fokker-Planck collision operator. Collisions decorrelate the ions from the acoustic waves in SBS, which disrupts ion trapping in the acoustic wave. Nevertheless, ion trapping leading to a hot ion tail and two-dimensional physics that allows the SBS ion waves to nonlinearly scatter remain robust saturation mechanisms for SBBS in a high-gain limit over a range of ion collisionality. …

We present a three-dimensional modeling study of gas flow inthe unsaturated fractured rock of Yucca Mountain. Our objective is toestimate large-scale fracture permeability, using the changes insubsurface pneumatic pressure in response to barometric pressure changesat the land surface. We incorporate the field-measured pneumatic datainto a multiphase flow model for describing the coupled processes ofliquid and gas flow under ambient geothermal conditions. Comparison offield-measured pneumatic data with model-predicted gas pressures is foundto be a powerful technique for estimating the fracture permeability ofthe unsaturated fractured rock, which is otherwise extremely difficult todetermine on the large scales of interest. In addition, this studydemonstrates that the multi-dimensional-flow effect on estimatedpermeability values is significant and should be included whendetermining fracture permeability in heterogeneous fracturedmedia.

As the National Hydrogen Economy continues to develop and evolve the need for structural materials that can resist hydrogen assisted degradation will become critical. To date austenitic stainless steel materials have been shown to be mildly susceptible to hydrogen attack which results in lower mechanical and fracture strengths. As a result, hydrogen permeation barrier coatings are typically applied to these steel to retard hydrogen ingress. The focal point of the reported work was to evaluate the potential for intentional alloying of commercial 300-series stainless steels to promote hydrogen permeation resistant oxide scales. Previous research on the Cr- and Fe-oxide scales inherent to 300-series stainless steels has proven to be inconsistent in effecting permeation resistance. The approach undertaken in this research was to add aluminum to the 300-series stainless steels in an attempt to promote a pure Al-oxide or and Al-rich oxide scale. Aloxide had been previously demonstrated to be an effective hydrogen permeation barrier. Results for 304L and 347H alloys doped with Al in concentration from 0.5-3.0 wt% with respect to oxidation kinetic studies, cyclic oxidation and characterization of the oxide scale chemistry are reported herein. Gaseous hydrogen permeation testing of the Al-doped alloys in both the unoxidized and oxidized …

Many materials and electronics need to be tested for the radiation environment expected at linear colliders (LC) since both accelerator and detectors will be subjected to large fluences of hadrons, leptons and {gamma}'s over the life of the facility [1]. While the linacs will be superconducting, there are still many uses for NdFeB in the damping rings, injection and extraction lines and final focus. Our understanding of the situation for rare earth, permanent magnet materials was presented at PAC03 [2]. Our first measurements of fast neutron, stepped doses at the UC Davis McClellan Nuclear Reactor Center (UCD MNRC) were presented at EPAC04 [3]. We have extended the doses, included other manufacturer's samples, and measured induced radioactivities which are discussed in detail.

Recently the first hohlraum experiments have been performed at the National Ignition Facility (NIF) in support of indirect drive Inertial Confinement Fusion (ICF) designs. The effects of laser beam smoothing by spectral dispersion (SSD) and polarization smoothing (PS) on the beam propagation in long scale gas-filled pipes has been studied at plasma scales as found in indirect drive gas filled ignition hohlraum designs. The long scale gas-filled target experiments have shown propagation over 7 mm of dense plasma without filamentation and beam break up when using full laser smoothing. Vacuum hohlraums have been irradiated with laser powers up to 6 TW, 1-9 ns pulse lengths and energies up to 17 kJ to activate several diagnostics, to study the hohlraum radiation temperature scaling with the laser power and hohlraum size, and to make contact with hohlraum experiments performed at the NOVA and Omega laser facilities. Subsequently, novel long laser pulse hohlraum experiments have tested models of hohlraum plasma filling and long pulse hohlraum radiation production. The validity of the plasma filling assessment in analytical models and in LASNEX calculations has been proven for the first time. The comparison of these results with modeling will be discussed.

FLYCHK is a straightforward, rapid tool to provide ionization and population distributions of plasmas in zero dimension with accuracy sufficient for most initial estimates and in many cases applicable for more sophisticated analysis. FLYCHK solves rate equations for level population distributions by considering collisional and radiative atomic processes. The code is designed to be straightforward to use and yet is general enough to apply for most laboratory plasmas. Further, it can be applied for low-to-high Z ions and in either steady-state or time-dependent situations. Plasmas with arbitrary electron energy distributions, single or multiple electron temperatures can be studied as well as radiation-driven plasmas. To achieve this versatility and accuracy in a code that provides rapid response we employ schematic atomic structures, scaled hydrogenic cross-sections and read-in tables. It also employs the jj configuration averaged atomic states and oscillator strengths calculated using the Dirac-Hartree-Slater model for spectrum synthesis. Numerous experimental and calculational comparisons performed in recent years show that FLYCHK provides meaningful estimates of ionization distributions, well within a charge state for most laboratory applications.