In this paper some of the results of a recent computer search [CoLy99] for optimal three- and four-dimensional lattice rules of specified trigonometric degree are discussed. The theory is presented in a general frame emphasizing the special nature of lattice rules among the rules of specified trigonometric degree.

The authors present the Sequential Access Model (SAM), which is the data handling system for D0, one of two primary High Energy Experiments at Fermilab. During the next several years, the D0 experiment will store a total of about 1 PByte of data, including raw detector data and data processed at various levels. The design of SAM is not specific to the D0 experiment and carries few assumptions about the underlying mass storage level; its ideas are applicable to any sequential data access. By definition, in the sequential access mode a user application needs to process a stream of data, by accessing each data unit exactly once, the order of data units in the stream being irrelevant. The units of data are laid out sequentially in files. The adopted model allows for significant optimizations of system performance, decrease of user file latency and increase of overall throughput. In particular, caching is done with the knowledge of all the files needed in the near future, defined as all the files of the already running or submitted jobs. The bulk of the data is stored in files on tape in the mass storage system (MSS) called Enstore[2] and also developed at Fermilab. …

Single-shot spectrum measurements of the radiation emitted by an electron bunch provide a novel way to characterize the bunch shape. Shot noise fluctuations in the longitudinal beam density result in radiation with a spectrum that consists of spikes with width inversely proportional to the bunch length. The variance of the Fourier transform of the spectrum is proportional to the convolution function of the beam current averaged over many bunches. After the convolution function is found, the phase retrieval technique can be applied to recover the bunch shape. This technique has been used to analyze the shape of the 4-ps-long bunches at the Low-Energy Undulator Test Line at the Advanced Photon Source.

The superhistory method is incorporated, in different implementations, into two versions of MONK. In this paper the authors intercompare the efficiencies of these implementations via the Figure Of Merit (FOM), and compare the efficiencies of each with that of conventional Monte Carlo (MC). Finally, they suggest preferred versions of MC for eigenvalue calculations. Here, FOM {approx} 1/N{sigma}{sup 2}, where N is the number of histories, and {sigma} is the variance of a quantity of interest. In the criticality-safety version MONK, fission is simulated as suggested in Ref. 1 (Method-1). Every absorption site is a potential fission site, with weight W = {sigma}{sub f}/kx{sigma}{sub a}, where {sigma}{sub f} and {sigma}{sub a} are fission and absorption cross sections, and k is an estimate of the eigenvalue. If W < 1, W is taken as pf, the fission probability. A Method-1 fission produces, on average, {nu} offspring at each site. The reactor-physics MONK uses the standard MC fission treatment (Method-0), i.e. {nu}xW is the average number of neutrons born in a fission, and pf = 1. For consistency, they take absorption sites as potential fission sites in both methods. For v = 1 and a single generation per supergeneration, conventional and superhistory methods …

A single-pass, high-gain free-electron laser (FEL) x-ray amplifier was simulated using the 3D, polychromatic simulation code MEDUSA. The seed for the system is a table-top, soft x-ray laser. The simulated fundamental and nonlinear harmonic x-ray output wavelengths are discussed.

The specifications of presently proposed x-ray free electron lasers (FELs) are for machines that will provide x-ray pulses as short as 100 fs with a photon energy as high as 12.3 keV. Since the pulse will contain as much as 5 mJ of energy, these devices will present the experimenter with an opportunity to expose matter to an unprecedented x-ray energy density. This high concentration of energetic x-rays presents both a promising frontier in energy-matter interaction, as well as a technological crevasse to be crossed by the experimenter attempting to use the FEL beam. The authors shall look at three possible problems confronting the experimenter: (1) synchronization of a detector, laser pulse, etc., to the FEL pulse; (2) radiation damage to the target sample; and (3) the presence of an electromagnetic pulse that could damage sensitive electronics located in the experimental area.

Measurements of self-amplified spontaneous emission (SASE) at 530 nm were made at the Advanced Photon Source (APS) low-energy undulator test line facility (LEUTL). Exponential growth of the optical signal as a function of distance was measured and compared to theoretical estimates. SASE was first observed using a beam generated from a photocathode rf gun system. It was later repeated using beam from a thermonic rf gun system. Following a brief description of the LEUTL facility, they present their results and initial analysis.

The authors reviewed the current status of a proposed KAMI (Kaon at Main Injector) experiment at Fermilab to measure the direct CP-violating K{sub L} {r_arrow} {pi}{sup 0}{nu}anti-{nu} decay. Good progress and encouraging results have been made in the past two years for measuring the required photon veto inefficiencies for both CsI and lead-scintillator detectors in a test beam at INS-KEK Japan. New beam test with 150 GeV Main Injector protons has also been scheduled in January 2000 at Fermilab using the existing KTeV detector with two new beam calorimeters. Prospects of a feasible KAMI experiment in the future is discussed here.

The CDF detector at the Tevatron Collider (Fermilab) has collected data from 1992 to 1995. During these years they performed several measurements by using B hadronic decays. All the analysis exploited lepton triggers. The new measurements the authors present here are on radiative B decays B {r_arrow} K{sup 0*} {gamma}, B {r_arrow} {var_phi}{gamma} and {Lambda}{gamma}. They show also preliminary study for the determination of the branching ratios B {r_arrow} J/{psi}K{sup +}{pi}{sup +}{pi}{sup {minus}} and B {r_arrow} {chi}{sub c} (1P) K{sup +}. In view of Run II they discuss CDF reaches using fully reconstructed B hadronic decays. This is done by scaling the number of events and the efficiencies found in Run I without rely on Monte Carlo simulation whenever it is possible.

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The next generation of large-scale free-electron lasers (FELs) such as Euro-XFEL and LCLS are to be devices which produce coherent X-rays using Self-Amplified Spontaneous Emission (SASE). The performance of these devices is limited by the spread in longitudinal velocities of the beam. In the case where this spread arises primarily from large transverse oscillation amplitudes, beam conditioning can significantly enhance FEL performance. Future X-ray sources may also exploit harmonic generation starting from laser-seeded modulation. Preliminary analysis of such devices is discussed, based on a novel trial-function/variational-principle approach, which shows good agreement with more lengthy numerical simulations.

The Gordon Research Conference (GRC) on MULTIPHOTON PROCESSES was held at Tilton School, Tilton, NH. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

In string-inspired semi-realistic heterotic orbifolds models with an anomalous U(1){sub X},a nonzero Kobayashi-Masakawa (KM) phase is shown to arise generically from the expectation values of complex scalar fields, which appear in nonrenormalizable quark mass couplings. Modular covariant nonrenormalizable superpotential couplings are constructed. A toy Z{sub 3} orbifold model is analyzed in some detail. Modular symmetries and orbifold selection rules are taken into account and do not lead to a cancellation of the KM phase. We also discuss attempts to obtain the KM phase solely from renormalizable interactions.

A sufficiently large acceptance is critical for the NLC Main Damping Rings (MDR) as the high power carried by the beams demands very high injection efficiency. Chromatic sextupoles and wiggler insertions (needed for rapid damping) are substantial sources of nonlinearities limiting the dynamic aperture. We report on the techniques we are using for analysis of single-particle beam dynamics in the presence of wiggler fields with significant nonlinear components. We demonstrate that our approach gives results in good agreement with experimental data when applied to the BL11 wiggler in SPEAR2, and discuss the present status of studies for the NLC MDR.

A design for a high gradient, low inductance pulsed quadrupole magnet is presented. The magnet is a circular current dominated design with a circular iron return yoke. Conductor angles are determined by a method of direct multipole elimination which theoretically eliminates the first four higher order multipole field components. Coils are fabricated from solid round film-insulated conductor, wound as a single layer ''non-spiral bedstead'' coil having a diagonal leadout entirely within one upturned end. The coils are wound and stretched straight in a special winder, then bent in simple fixtures to form the upturned ends.

We present non-equilibrium molecular dynamics (MD) simulations of wave propagation in nanocrystals. We find that the width of the traveling wave front increases with grain size, d, as d{sup 1/2}. This width also decreases with the pressure behind the front. We extrapolate our results to micro-crystals and obtain reasonable agreement with experimental data. In addition, our extrapolation agrees with models that only take into account the various velocities of propagation along different crystalline orientations, without including grain boundary effects. Our results indicate that, even at the nanoscale, the role of grain boundaries as scattering centers or as sources of plasticity does not increase significantly the width of the traveling wave.

During the past two years, significant experimental and theoretical progress has been made in the US heavy ion fusion science program in longitudinal beam compression, ion-beam-driven warm dense matter, beam acceleration, high brightness beam transport; and advanced theory and numerical simulations. Innovations in longitudinal compression of intense ion beams by > 50 X propagating through background plasma enable initial beam target experiments in warm dense matter to begin within the next two years. They are assessing how these new techniques might apply to heavy ion fusion drivers for inertial fusion energy.

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Recent advances in sequencing technologies promise better diagnostics for many diseases as well as better understanding of evolution of microbial populations. Single Nucleotide Polymorphisms(SNPs) are established genetic markers that aid in the identification of loci affecting quantitative traits and/or disease in a wide variety of eukaryotic species. With today's technological capabilities, it is possible to re-sequence a large set of appropriate candidate genes in individuals with a given disease and then screen for causative mutations.In addition, SNPs have been used extensively in efforts to study the evolution of microbial populations, and the recent application of random shotgun sequencing to environmental samples makes possible more extensive SNP analysis of co-occurring and co-evolving microbial populations. The program is available at http://genome.lbl.gov/vista/snpvista.

This paper will discuss the Safeguards & Security (S&S) activities that resulted in the downgrade of the Savannah River Site's FB-Line (FBL) from a Category I Material Balance Area (MBA) in a Material Access Area (MAA) to a Category IV MBA in a Property Protection Area (PPA). The Safeguards activities included measurement of final product items, transferal of nuclear material to other Savannah River Site (SRS) facilities, discard of excess nuclear material items, and final measurements of holdup material. The Security activities included relocation and destruction of classified documents and repositories, decertification of a classified computer, access control changes, updates to planning documents, deactivation and removal of security systems, Human Reliability Program (HRP) removals, and information security training for personnel that will remain in the FBL PPA.

We present measurements of the Branching Fraction and photon energy spectrum in B {yields} X{sub S}{gamma} decays in a sample of 89 million B{bar B} pairs collected at the BABAR detector at Stanford Linear Accelerator Center's PEP-II asymmetric B-factory. Results from a fully-inclusive and a sum of 38 exclusive final states techniques are presented and found to be consistent with the Standard Model calculations, as well as experimental results obtained from semileptonic B {yields} X{sub c}lv decays.