Recent work in heavy-ion fusion accelerators and final focusing systems shows a trend towards less current per beam, and thus, a greater number of beams. Final focusing magnets are susceptible to nuclear heating, radiation damage, and neutron activation. The trend towards more beams, however, means that there can be less shielding for each magnet, Excessive levels of nuclear heating may lead to magnet quench or an intolerable recirculating power for magnet cooling. High levels of radiation damage may result in short magnet lifetimes and low reliability. Finally, neutron activation of the magnet components may lead to difficulties in maintenance, recycling, and waste disposal. The present work expands upon previous, three-dimensional magnet shielding calculations for a modified version of the HYLIFE-I1 IFE power plant design. We present key magnet results as a function of the number of beams.

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.

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 …

None

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.

None