Some ionic liquids (ILs) have been shown to be very effective solvents for biomass pretreatment. It is known that some ILs can have a strong inhibitory effect on fungal cellulases, making the digestion of cellulose inefficient in the presence of ILs. The identification of IL-tolerant enzymes that could be produced as a cellulase cocktail would reduce the costs and water use requirements of the IL pretreatment process. Due to their adaptation to high salinity environments, halophilic enzymes are hypothesized to be good candidates for screening and identifying IL-resistant cellulases. Using a genome-based approach, we have identified and characterized a halophilic cellulase (Hu-CBH1) from the halophilic archaeon, Halorhabdus utahensis. Hu-CBH1 is present in a gene cluster containing multiple putative cellulolytic enzymes. Sequence and theoretical structure analysis indicate that Hu-CBH1 is highly enriched with negatively charged acidic amino acids on the surface, which may form a solvation shell that may stabilize the enzyme, through interaction with salt ions and/or water molecules. Hu-CBH1 is a heat tolerant haloalkaliphilic cellulase and is active in salt concentrations up to 5 M NaCl. In high salt buffer, Hu-CBH1 can tolerate alkali (pH 11.5) conditions and, more importantly, is tolerant to high levels (20percent w/w) of ILs, …

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We apply the Basis Light-Front Quantization (BLFQ) approach to the Hamiltonian field theory of Quantum Electrodynamics (QED) in free space. We solve for the mass eigenstates corresponding to an electron interacting with a single photon in light-front gauge. Based on the resulting non-perturbative ground state light-front amplitude we evaluate the electron anomalous magnetic moment. The numerical results from extrapolating to the infinite basis limit reproduce the perturbative Schwinger result with relative deviation less than 1.2%. We report significant improvements over previous works including the development of analytic methods for evaluating the vertex matrix elements of QED.

The behavior of the longitudinal wake fields excited by a very short bunch in the SLAC S-band constant gradient accelerating structures has been studied. Wake potential calculations were performed for a bunch length of 10 microns using the author's code to obtain a numerical solution of Maxwell's equations in the time domain. We have calculated six accelerating sections in the series (60-ft) to find the stationary solution. While analyzing the computational results we have found a new formula for the Green's function. Wake potentials, which are calculated using this Green's function are in amazingly good agreement with numerical results over a wide range of bunch lengths. The Green's function simplifies the wake potential calculations and can be easily incorporated into the tracking codes. This is very useful for beam dynamics studies of the linear accelerators of LCLS and FACET.

A method is proposed for the calculation of the short-range wake field potentials of an ultra-relativistic bunch passing near some irregularities in a beam pipe. The method is based on the space-time domain integration of Maxwell's equations using Kirchhoff's formulation. We demonstrate this method on two cases where we obtain the wake potentials for the energy loss of a bunch traversing an iris-collimator in a beam pipe and for a cavity. Likewise, formulas are derived for Green's functions that describe the transverse force action of wake fields. Simple formulas for the total energy loss of a bunch with a Gaussian charge density distribution are derived as well. The derived estimates are compared with computer results and predictions of other models.

In this very brief talk, we'll discuss how precision engineering impacts 4 key areas of NIF: (1) Diamond turning of KDP crystals; (2) Mitigation of laser damage on optics; (3) Alignment of lasers, targets, diagnostics; (4) Target fabrication.

After the successful operation of FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source), soft and hard X-ray Free Electron Lasers (FELs) are being built, designed or proposed at many accelerator laboratories. Acceleration employing lower frequency RF cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic RF system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency RF acceleration process. In this paper, a hard X-ray FEL design using an all X-band accelerator at 11.424 GHz (from photo-cathode RF gun to linac end) is presented, without the assistance of any harmonic RF linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (RMS), low charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macro-particle 3-D simulation employing several computer codes is presented in this paper, where space charge, wakefields, incoherent and coherent synchrotron radiation (ISR and …

We introduce a jet shape observable defined for an ensemble of jets in terms of two-particle angular correlations and a resolution parameter R. This quantity is infrared and collinear safe and can be interpreted as a scaling exponent for the angular distribution of mass inside the jet. For small R it is close to the value 2 as a consequence of the approximately scale invariant QCD dynamics. For large R it is sensitive to non-perturbative effects. We describe the use of this correlation function for tests of QCD, for studying underlying event and pile-up effects, and for tuning Monte Carlo event generators.

Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and - most recently - experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as two thousand, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to two hundred on large capsule sectors have run through ignition and burn, and …

We analyze the phases of supersymmetric chiral gauge theories with an antisymmetric tensor and (anti)fundamental flavors, in the presence of a classically marginal superpotential deformation. Varying the number of flavors that appear in the superpotential reveals rich infrared chiral dynamics and novel dualities. The dualities are characterized by an infinite family of magnetic duals with arbitrarily large gauge groups describing the same fixed point, correlated with arbitrarily large classical global symmetries that are truncated nonperturbatively. At the origin of moduli space, these theories exhibit a phase with confinement and chiral symmetry breaking, an interacting nonabelian Coulomb phase, and phases where an interacting sector coexists with a sector that either s-confines or is in a free magnetic phase. Properties of these intriguing 'mixed phases' are studied in detail using duality and a-maximization, and the presence of superpotential interactions provides further insights into their formation.

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