A5044489249- Nuclear Physics and Applications
- Nuclear physics research studies
- Nuclear reactor physics and engineering
- Cosmology and Gravitation Theories
- Nuclear Materials and Properties
- Radiation Detection and Scintillator Technologies
- Galaxies: Formation, Evolution, Phenomena
- Radio Astronomy Observations and Technology
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- Atomic and Molecular Physics
- Astrophysics and Star Formation Studies
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Stellar, planetary, and galactic studies
- Fusion materials and technologies
- Nuclear and radioactivity studies
- Scientific Research and Discoveries
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Spectroscopy and Chemometric Analyses
- Dark Matter and Cosmic Phenomena
- Ultrasonics and Acoustic Wave Propagation
- Advanced Measurement and Detection Methods
- Photonic and Optical Devices
Idaho National Laboratory
2009-2024
California Institute of Technology
2001-2016
Jet Propulsion Laboratory
2002-2015
Bechtel (United States)
2003
Florida State University
1994-1999
Tennessee Technological University
1995
Mississippi State University
1995
Vanderbilt University
1995
Kent State University
1992
The energies and $B({E2;0}_{\mathrm{g}.\mathrm{s}.}^{+}\ensuremath{\rightarrow}{2}_{1}^{+})$ values for the lowest ${J}^{\ensuremath{\pi}}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2}^{+}$ states in neutron-rich radioactive nuclei ${}^{38,40,42}\mathrm{S}$ ${}^{44,46}\mathrm{Ar}$ were measured via intermediate-energy Coulomb excitation. results ${}^{40,42}\mathrm{S}$ provide first evidence of moderate deformation near $N\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}28$, while...
The scientific performance of the Planck Low Frequency Instrument (LFI) after one year in-orbit operation is presented. We describe main optical parameters and discuss photometric calibration, white noise sensitivity, properties. A preliminary evaluation impact systematic effects For each parameters, we outline methods used to obtain them from flight data provide a comparison with pre-launch ground assessments, which are essentially confirmed in flight.
Power spectrum estimation and evaluation of associated errors in the presence incomplete sky coverage; non-homogeneous, correlated instrumental noise; foreground emission is a problem central importance for extraction cosmological information from cosmic microwave background. We develop Monte Carlo approach maximum likelihood power spectrum. The method based on an identity Bayesian posterior as marginalization over unknowns. Maximization involves computation expectation values sample average...
We describe the data processing pipeline of Planck Low Frequency Instrument (LFI) centre (DPC) to create and characterize full-sky maps based on first 15.5 months operations at 30, 44 70 GHz. In particular, we discuss various steps involved in reducing data, starting from telemetry packets through production cleaned, calibrated timelines frequency maps. Data are continuously using modulation induced mean temperature cosmic microwave background radiation by proper motion spacecraft. Sky...
We discuss the methods employed to photometrically calibrate data acquired by Low Frequency Instrument on Planck. Our calibration is based a combination of Orbital Dipole plus Solar Dipole, caused respectively motion Planck spacecraft with respect Sun and System CMB rest frame. The latter provides signal few mK same spectrum as anisotropies visible throughout mission. In this release we rely characterization measured WMAP. also present preliminary results (at 44GHz only) study which agree...
We describe the processing of data from Low Frequency Instrument (LFI) used in production Planck Early Release Compact Source Catalogue (ERCSC). In particular, we discuss steps involved reducing telemetry packets to cleaned, calibrated, time-ordered (TOD) and frequency maps. Data are continuously calibrated using modulation temperature cosmic microwave background radiation induced by motion spacecraft. Noise properties estimated TOD which sky signal has been removed a generalized least...
As microreactors evolve to become a more affordable and efficient worldwide energy source, the development of moderator material within system decrease required mass low-enriched uranium fuel is important. The use low- instead high-enriched in small nuclear reactors stems from recent national policies associated with nonproliferation. New designs are being developed for range applications space systems particular. Using geometries such as those described this paper, next step advance...
Planck has mapped the polarized dust emission over whole sky, making it possible to trace Galactic magnetic field structure that pervades interstellar medium (ISM). We combine polarization data from with rotation measure (RM) observations towards a massive star-forming region, Rosette Nebula in Monoceros molecular cloud, study its and impact of an expanding HII region on morphology field. derive analytical solution for field, assumed evolve initially uniform configuration following expansion...
Elastic and inelastic proton scattering has been measured in inverse kinematics on the unstable nucleus ${}^{40}\mathrm{S}$. A phenomenological distorted wave Born approximation analysis yields a quadrupole deformation parameter ${\ensuremath{\beta}}_{2}=0.35\ifmmode\pm\else\textpm\fi{}0.05$ for ${2}_{1}^{+}$ state. Consistent microscopic analyses have applied to all even-even sulfur isotopes from $A=32$ $A=40$. The second used collective model densities modified Jeukenne-Lejeune-Mahaux...
Abstract There is an increasing number of large, digital, synoptic sky surveys, in which repeated observations are obtained over large areas the multiple epochs. Likewise, there a growth (often automated or robotic) follow‐up facilities with varied capabilities terms instruments, depth, cadence, wavelengths, etc., most geared toward some specific astrophysical phenomenon. As detected transient events grows, automated, probabilistic classification variables and transients becomes increasingly...
A 39$A$ MeV ${}^{38}\mathrm{S}$ radioactive beam was used with inverse kinematics to measure angular distributions for elastic and inelastic proton scattering from a ${\mathrm{CH}}_{2}$ target. Optical potential folding model calculations are compared the distribution. Using coupled channel calculations, ${\ensuremath{\beta}}_{2}$ value ${2}_{1}^{+}$ state is determined be 0.35\ifmmode\pm\else\textpm\fi{}0.04. This value, when corresponding result Coulomb excitation measurement, leads...
New band structures in the neutron-rich 113,115,117Pd nuclei have been constructed by measuring γ−γ−γ coincidences emitted from spontaneous fission of 252Cf with GAMMASPHERE. The triple γ-ray coincidence data revealed new negative-parity bands built on 11/2− isomeric states 113,115,117Pd. These νh11/2 orbital suggest a crossing at frequency ħω≈0.45MeV. rotational behavior and energy level spacings these prolate shape. Two previously unreported are also observed 113,115Pd tentatively assigned...
The yrast band was significantly extended to 14+ and the γ 5+ in neutron-rich 118Pd by measuring γ-γ-γ coincidences emitted from spontaneous fission of 252Cf with Gammasphere. first crossing observed at a frequency ħω≈0.36 MeV starting point backbending, which is similar that found 112−116Pd. bandbending cascade interpreted be built on two h11/2 neutron configuration based its similarity bands even-even Our result indicates still maintains prolate shape. quasineutron Routhian calculations...
We have studied the electro-optic properties as a function of temperature polymer dispersed liquid crystal film composed E7 droplets in polyvinylformal (PVFM) matrix. The drive voltage and turn-off time change abruptly is raised above glass transition (Tg) PVFM There essentially no hysteresis below, but significant Tg. These effects are completely reversible. rapid cannot be entirely explained by changes dielectric or droplet shape. Freedericksz measurements show abrupt surface anchoring...
Exploration of time domain is now a vibrant area research in astronomy, driven by the advent digital synoptic sky surveys. While panoramic surveys can detect variable or transient events, typically some follow-up observations are needed; for short-lived phenomena, rapid response essential. Ability to automatically classify and prioritize events studies becomes critical as data rates increase. We have been developing such methods using streams from Palomar-Quest survey, Catalina Sky Survey...
We develop a new Bayesian method for estimating white noise levels in CMB sky maps, and apply this algorithm to the 5-year WMAP data. assume that amplitude of RMS is scaled by constant value, alpha, relative pre-specified level. then derive corresponding conditional density, P(alpha | s, Cl, d), which subsequently integrated into general Gibbs sampler. first verify our code analyzing simulated data sets, framework For foreground-reduced maps nominal initially provided release, we find...
The neutron-rich argon isotope ${}^{43}\mathrm{Ar}$ has been studied by quasielastic and inelastic proton scattering performed in inverse kinematics. measured angular distribution for the second excited state is good agreement with an $L=2$ transition. Assuming this transition to be $E2,$ yields a ${\ensuremath{\beta}}_{2}$ value of $0.25\ifmmode\pm\else\textpm\fi{}0.03$ when compared distorted-wave Born approximation calculations. This comparable one reported stable ${}^{40}\mathrm{Ar}.$...