The normalized $^{238}\mathrm{U}(n,f)/^{235}\mathrm{U}(n,f)$ cross section ratio has been measured using the NIFFTE fission Time Projection Chamber (fissionTPC) from the reaction threshold to $30\phantom{\rule{4pt}{0ex}}\mathrm{MeV}$. The fissionTPC is a two-volume MICROMEGAS time projection chamber that allows for full three-dimensional reconstruction of fission-fragment ionization profiles from neutron-induced fission. The measurement was performed at the Los Alamos Neutron Science Center, where the neutron energy is determined from neutron time of-flight. The $^{238}\mathrm{U}(n,f)/^{235}\mathrm{U}(n,f)$ ratio reported here is the first cross section measurement made with the fissionTPC, and will provide new experimental data for evaluation of the $^{238}\mathrm{U}(n,f)$ cross section, an important standard used in neutron-flux measurements. Use of a development target in this work prevented the determination of an absolute normalization, to be addressed in future measurements. Instead, the measured cross section ratio has been normalized to ENDF/B-VIII.$\ensuremath{\beta}5$ at 14.5 MeV.

This document presents the Conceptual Design Report (CDR) put forward by an international neutrino community to pursue the Deep Underground Neutrino Experiment at the Long-Baseline Neutrino Facility (LBNF/DUNE), a groundbreaking science experiment for long-baseline neutrino oscillation studies and for neutrino astrophysics and nucleon decay searches. The DUNE far detector will be a very large modular liquid argon time-projection chamber (LArTPC) located deep underground, coupled to the LBNF multi-megawatt wide-band neutrino beam. DUNE will also have a high-resolution and high-precision near detector.

The U-233,U-234,U-236,U-238 fission cross sections have been measured relative to U-235(n, f) for incident neutron energies from 200 keV to 200 MeV using neutron time-of-flight at the Los Alamos Neutron Science Center. The results are generally consistent with the current ENDF/B-VII evaluation, but some discrepancies with previous measurements above 20 to 30 MeV are observed. These measurements are part of a campaign to measure fission cross sections with high precision in support of fast reactor technology.

A well established program of neutron-induced fission cross section measurement at Los Alamos Neutron Science Center (LANSCE) is supporting the Fuel Cycle Research program (FC R&D). The incident neutron energy range spans from sub-thermal up to 200 MeV by combining two LANSCE facilities, the Lujan Center and the Weapons Neutron Research facility (WNR). The time-of-flight method is implemented to measure the incident neutron energy. A parallel-plate fission ionization chamber was used as a fission fragment detector. The event rate ratio between the investigated foil and a standard U-235 foil is converted into a fission cross section ratio. In addition to previously measured data new measurements include U-236 data which is being analyzed, and U-234 data acquired in the 2011-2012 LANSCE run cycle. The new data complete the full suite of Uranium isotopes which were investigated with this experimental approach. Obtained data are presented in comparison with existing evaluations and previous data.

A well established program of neutron-induced fission cross section measurement at Los Alamos Neutron Science Center (LANSCE) is supporting the Fuel Cycle Research program (FC R&D). The incident neutron energy range spans from sub-thermal up to 200 MeV by combining two LANSCE facilities, the Lujan Center and the Weapons Neutron Research facility (WNR). The time-of-flight method is implemented to measure the incident neutron energy. A parallel-plate fission ionization chamber was used as a fission fragment detector. The event rate ratio between the investigated foil and a standard 235U foil is converted into a fission cross section ratio. In addition to previously measured data new measurements include 236U data which is being analyzed, and 234U data acquired in the 2011-2012 LANSCE run cycle. The new data complete the full suite of Uranium isotopes which were investigated with this experimental approach. Obtained data are presented in comparison with existing evaluations and previous data.

A well established program of neutron-induced fission cross section measurement at Los Alamos Neutron Science Center (LANSCE) is supporting the Fuel Cycle Research program (FC R&D). Combining measurements at two LANSCE facilities, the Lujan Center and the Weapons Neutron Research facility (WNR), cover neutron energies over 10 orders of magnitude: from sub-thermal up to 200 MeV. A parallel-plate fission ionization chamber was used as a fission fragment detector. The (235)U(()n,f) standard was used as the reference. Fission cross sections have been measured for multiple actinides. The new data presented here completes the suite of long-lived Uranium isotopes that were investigated with this experimental approach. The cross section data are presented in comparison with existing evaluations and previous measurements.

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub thermal energies up to 200 MeV. Parallel‐plate ionization chambers are used to measure fission cross sections ratios relative to the 235U standard while incident neutron energies are determined using the time‐of‐flight method. Recent measurements include the 233,238U, 239–242Pu and 243Am neutron‐induced fission cross sections. Obtained data are presented in comparison with existing evaluations and previous data.

Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the (235)U standard. Recent measurements include the (233,238)U, (239-242)Pu, and (243)m neutron-induced fission cross sections. In this paper preliminary results for fission cross sections of (243)Am and (233)U will be presented.

AbstractThe 239Pu and 241Pu neutron-induced fission cross sections have been measured from subthermal energies to 200 MeV. These measurements are part of a campaign to measure fission cross sections with high precision in support of advanced fast reactor technology. Plutonium-241 is the most active target measured in this program to date, with a half-life of 14.4 yr. The results for 239Pu are in good agreement with previous experiments and add new information to the limited knowledge on the fission cross section above 30 MeV. Discrepancies of up to 30% between the evaluations and the experimental data for 241Pu are found in the fast region, which is of particular importance for fast spectrum reactor technology, and a reevaluation of the fission cross section for this isotope is recommended.

The (PU)-P-239 and Pu-241 neutron-induced fission cross sections have been measured from subthermal energies to 200 MeV. These measurements are part of a campaign to measure fission cross sections with high precision in support of advanced fast reactor technology. Plutonium-241 is the most active target measured in this program to date, with a half-life of 14.4 yr. The results for Pu-239 are in good agreement with previous experiments and add new information to the limited knowledge on the fission cross section above 30 MeV. Discrepancies of up to 30% between the evaluations and the experimental data for Pu-241 are found in the fast region, which is of particular importance for fast spectrum reactor technology, and a reevaluation of the fission cross section for this isotope is recommended.

The neutron induced fission cross sections of Pu-240,Pu-242 have been measured as a function of incident neutron energy from 1 eV to 200 MeV. This is part of an effort to reduce experimental uncertainties of nuclear data in support of next generation nuclear reactors and transmutation technology. These two plutonium isotopes are nonfissile, and the available data are limited below reaction threshold. The present data demonstrate the presence of a 2.67 eV resonance in the Pu-242 fission cross section, which is missing in the ENDF/B-VII evaluation, and resolve discrepancies in the keV region. The measured cross sections are also compared with statistical model calculations made with the nuclear reaction code GNASH.

We report a measurement of the exclusive B+ meson decay to the D-s(()*K-)(+)pi(+) final state using 657 x 10(6) B (B) over bar pairs collected at the gamma(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We use D-s* -> D-s(-) -> phi pi(-), (K) over bar*(892)K-0(-) and (KSK-)-K-0 decay modes for D-s(()*()) reconstruction and measure the following branching fractions: B(B+ -> Ds-K+pi(+)) = (1.71(-0.07)(+0.08)(stat)(-0.20)(+0.20)(syst) +/- 0.15(B-int)) x 10(-4) and B(B+ -> D-s*K--(+)pi(+)) = (1.31(-0.12)(+0.13)(stat)(-0.25)(+0.25)(syst) +/- 0.12(B-int)) x 10(-4). The uncertainties are due to statistics, experimental systematic errors, and uncertainties of intermediate branching fractions, respectively.

Using the CLEO II detector operating at the CESR ee collider, we have measured the structure functions in the decay τ → πππντ , based on a sample corresponding to 4 × 10 produced τ -pair events. We determine the integrated structure functions, which depend only on the three pion invariant mass, as well as the structure functions differential in the Dalitz plot. We extract model independent limits on non-axial-vector contributions from the measured structure functions as less than 16.6% of the total branching fraction, at the 95% confidence level. Separating the non-axial-vector contributions into scalar and vector contributions, we measure that scalars (vectors) contribute with less than 9.4% (7.3%) to the total branching ratio, at the 95% confidence level. PACS numbers: 13.25.Jx, 13.35.Dx, 14.40.Cs, 14.60.Fg Typeset using REVTEX

The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross sections for certain “minor” actinides. For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from “minor” actinides that currently have poorly known or in some cases not measured (n,γ) and (n,f) cross sections. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 239Pu, 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. The chemical purification and electodeposition techniques will be described.

We describe a measurement of B−B0 mixing parameters exploiting a method of partial reconstruction of the decay chains B → Dπ and B → Dρ. Using 9.6 ×10BB pairs collected at the Cornell Electron Storage Ring, we find χd = 0.198 ± 0.013 ± 0.014, |yd| < 0.41 at 95% confidence level, and |Re(ǫB)| < 0.034 at 95% confidence level.