The Superconducting Source for Ions SuSI) is a newly designed, fully superconducting Electron Cyclotron Resonance ECR) ion source working at 14.5 and 18 GHz microwave frequencies at the National Superconducting Cyclotron Laboratory NSCL). Preliminary results indicate that SuSI is capable of producing ion beam currents comparable to other 18 GHz sources[1]. In parallel to the increase in beam currents offered by SuSI compared to existing sources at the NSCL, a dedicated collimation channel has been designed to tailor the beam emittances to the K500 cyclotron acceptance, which is about 75 pimmamrad[?], so as tcy minimize the beam losses in the cyclotron extraction channel. The collimation channel uses four collimation stages and three solenoids in between to rotate the beam transversely in phase space. Beam simulations showed that the proposed design can efficiently collimate Learns from SuSI under various scenarios. The collimation channel was commissioned with SuSI in a test area in June 2009. Experimental results have confirmed the effective collimation capability observed in the beam simulations. The collimation channel anti SuSI were moved to the Coupled Cyclotron Facility CCF) ECR. area in July 2009 in replacement of the former 6 GHz SuperConducting ECR ion source SC-ECR). Since then the collimation channel has been recommissioned and provided adequate capability for emittance collimation and ECR parameter optimization at the CCF.

We study primordial nucleosynthesis abundance yields for assumed ranges of cosmological lepton numbers, sterile neutrino mass-squared differences and active-sterile vacuum mixing angles. We fix the baryon-to-photon ratio at the value derived from the cosmic microwave background CMB) data and then calculate the deviation of the 2H, 4He, and 7Li abundance yields from those expected in the zero lepton numbers), no-new-neutrino-physics case. We conclude that high precision &lt； 5% error) measurements of the primordial 2H abundance from, e.g., QSO absorption line observations coupled with high precision &lt； 1% error) baryon density measurements from the CMB could have the power to either: 1) reveal or rule out the existence of a light sterile neutrino if the sign of the cosmological lepton number is known； or 2) place strong constraints on lepton numbers, sterile neutrino mixing properties and resonance sweep physics. Similar conclusions would hold if the primordial 4He abundance could be determined to better than 10%. We have performed new Big Bang Nucleosynthesis calculations which employ arbitrarily-specified, time-dependent neutrino and antineutrino distribution functions for each of up to four neutrino flavors. We self-consistently couple these distributions to the thermodynamics, the expansion rate and scale factor-time/temperature relationship, as well as to all relevant weak, electromagnetic, and strong nuclear reaction processes in the early universe. With this approach, we can treat any scenario in which neutrino or antineutrino spectral distortion might arise. These scenarios might include, for example, decaying particles, active-sterile neutrino oscillations, and active-active neutrino oscillations in the presence of significant lepton numbers. Our calculations allow lepton numbers and sterile neutrinos to be constrained with observationally-determined primordial helium and deuterium abundances. We have modified a standard BBN code to perform these calculations and have made it available to the community. We have applied a fully relativistic Coulomb wave correction to the weak reactions in the full Kawano/Wagoner Big Bang Nucleosynthesis BBN) code. We have also added the zero temperature radiative correction. We find that using this higher accuracy Coulomb correction results in good agreement with previous work, giving only a modest &sim； 0.04% increase in helium mass fraction over correction prescriptions applied previously in BBN calculations. We have calculated the effect of these corrections on other light element abundance yields in BBN and we have studied these yields as functions of electron neutrino lepton number. This has allowed insights into the role of the Coulomb correction in the setting of the neutron-to-proton ratio during the BBN epoch. We find that the lepton capture processes contributions to this ratio are only second order in the Coulomb correction.

In this work, we undertook an exploratory study of QCD thermodynamics with domain-wall fermions. This had been studied before but with much smaller lattices and a heavier pion. In this new study, we report on results obtained on much larger volumes and discuss what needs to be done to go even closer to the chiral limit. A second new aspect of our study was the introduction of a chemical potential for the first time in the domain-wall formalism. We measured the lowest-order quark number susceptibilities and found a well-defined, smooth transition in some of these susceptibilities. We also carried out several analytic calculations in the free-field case. One motivation was to understand how these fermions worked, especially with respect to thermodynamic simulations. However another motivation was to understand cutoff effects, which had not been studied before for these fermions. We found that these effects were significant for the free operator. We therefore implemented and tested an improved version of the operator with much smaller discretization errors. In this work, we also present some preliminary results of simulations that show that observables measured using this operator show much smaller cutoff errors.

Our group has constructed a Wu-type superconducting beta spectrometer. This spectrometer will be used to investigate the properties of nuclear beta decay, starting with a measurement of the 14O ground state spectrum. To prepare for the 14O measurement, we have calibrated the spectrometer through careful examination of conversion electron spectra from 212Pb and 207Bi sources, and with measurements of the 42K beta decay spectrum. Additionally, we have treated the ground state beta decay of 66Ga as the test case for the future 14O experiment. Experiments to find the 66Ga half-life, decay energy, and spectrum shape resulted in the highest precision measurements of those properties to date. In making these measurements, we have found that a high-precision measurement of the 14O shape factor is possible with our spectrometer.

In Nucleon-Nucleon interactions, the weak interaction properties are not well understood. Meson exchange models use several couplings to describe the interaction, but most of these couplings are not well known. Constraints of them must come from experiments. We focused on the parity non-conserving spin rotation of the transversely polarized neutrons passing through liquid helium, which in meson exchange models is strongly correlated to the pion exchange coupling, f pi, and the rho exchange coupling h0r . The experiment used a magnetically shielded multi-chamber liquid helium target, to neutralize the much larger parity conserving spin rotations from environmental B field, and to isolate the desired parity violating rotation. The experiment was designed to achieve a sensitivity goal of &sim；3.0 x &sim；10 -7 rad/m. In this thesis we describe the theory, apparatus, and the result of the analysis of the data taken at NIST.

Measurements of the deuteron cross section and vector and tensor analyzing powers (Ay and Ayy) in d ＋ d elastic and d ＋ d &rarr； p ＋ t channels were performed at 130 and 180 MeV, using a polarized deuteron beam at the KVI in Groningen, the Netherlands. These measurements were done in order to provide a testing ground for the theoretical treatment of the initial deuteron entrance channel, which had previously overestimated total cross section measurements for d ＋ d &rarr； 4He＋pi0 (CSB Experiment, 2002), and is based on a Neumann series expansion of the AGS equations. Additional measurements were also made of the d ＋ p elastic cross section and analyzing powers at 130 and 180 MeV for use as a benchmark. Data was taken using the BBS (Big Bite Spectrometer), and beam polarization was monitored using the IBP (In Beam Polarimeter) at the KVI； analysis was performed using software written at IUCF. This measurement of the d＋p elastic cross section and analyzing powers compares favorably with similar d＋p elastic measurements taken previously (ranging from Ed＝56.380 MeV). Comparison of all d ＋ p elastic cross section data as a function of momentum transfer shows a clear energy independent scaling region； the KVI/IUCF d＋p cross section data is consistent with this feature. Furthermore, a similar comparison of our d ＋ d elastic data with previous measurements (ranging from E d＝56.232 MeV) shows similar features, and again suggests that our data is consistent with other measurements. Agreement of theory with d ＋ d data is best at energies above 200 MeV, where it qualitatively describes their general features, however agreement is lost as the energy goes down to 180 MeV and especially 130 MeV.

The heavy quark diffusion coefficient is the subject of a great deal of theoretical interest, with both phenomenology and AdS/CFT results pointing towards this transport coefficient being small in comparison to leading-order perturbative results. The heavy quarkantiquark bound state has been modeled with a Langevin equation that takes into account this small diffusion coefficient, as well as the interaction between the quarks in this pair. It was found that both the survival of J/psi particles in the most central collisions at the RHIC, and the thermalization of the relative abundances of charmonium states, can be explained with this model, where the destruction of quarkonium due to diffusion remains incomplete over the relevant timescales. Finally, this classical approach is replaced with a path integral which describes quarkonium as an open quantum system, so that comparisons can be made between this model and the results from lattice QCD simulations for certain quarkonium correlation functions.

Monte Carlo and quasi-Monte Carlo methods are among the most widely used methods for solving many problems that resist solution by other means. Among all such problems, the greatest challenges are posed by those that feature large numbers of independent variables, exemplified by quadrature of functions of many variables and solutions of large linear systems and integral equations. Under mild regularity conditions, conventional Monte Carlo simulations converge at the rate ON–1/2 )； where N ＝ number of independent samples, while conventional quasi-Monte Carlo qMC) methods converge at the rate Olog N)s/N) where s ＝ problem dimension and N is again the number of sample points. While the first is independent of dimension and the second depends only weakly on dimension, neither of these methods, used conventionally, provides a panacea for solving high dimensional problems quickly and efficiently. Substantial improvements in these rates are possible for the special class of qMC methods that make use of lattices. This dissertation is concerned with the use of lattice rules to obtain very high rates of convergence for high dimensional quadrature problems, and the methods developed should find use as well for solving infinite dimensional problems, as exemplified by matrix and integral equations. To gain access to these higher rates of convergence, certain regularity assumptions must be imposed. Provided the integrand is smooth and periodic, and when the lattices are chosen carefully, very great improvements in convergence can be attained. For example, using such techniques can achieve convergence rates of Olog N) alphas/Nalpha) with alpha ＞ 2 for dimension s. In this dissertation we use a novel approach based on importance sampling to achieve this objective. We also extend two strands of research that produce effectively computable lattices of high quality and we demonstrate their superiority in estimating high dimensional integrals by evaluating several test integrals studied by various authors earlier. Through the use of extremely high precision computations, we believe that we have demonstrated rates of convergence that exceed those reported anywhere in the literature.