8 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Ground States"  
Results: 1 - 8
open access

The Use of Trust Regions in Kohn-Sham Total EnergyMinimization

Description: The Self Consistent Field (SCF) iteration, widely used forcomputing the ground state energy and the corresponding single particlewave functions associated with a many-electronatomistic system, is viewedin this paper as an optimization procedure that minimizes the Kohn-Shamtotal energy indirectly by minimizing a sequence of quadratic surrogatefunctions. We point out the similarity and difference between the totalenergy and the surrogate, and show how the SCF iteration can fail whenthe minimizer … more
Date: May 30, 2006
Creator: Yang, Chao; Meza, Juan C. & Wang, Lin-wang
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Using the X-FEL to photo-pump X-ray laser transitions in He-like Ne

Description: Nearly four decades ago H-like and He-like resonantly photo-pumped laser schemes were proposed for producing X-ray lasers. However, demonstrating these schemes in the laboratory has proved to be elusive because of the difficulty of finding a strong resonant pump line. With the advent of the X-ray free electron laser (X-FEL) at the SLAC Linac Coherent Light Source (LCLS) we now have a tunable X-ray laser source that can be used to replace the pump line in previously proposed laser schemes and al… more
Date: August 30, 2011
Creator: Nilsen, J & Rohringer, N
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Hyperfine structure measurements in /sup 235/U I

Description: Using a pressure tuned narrowband pulsed dye laser we have investigated hyperfine effects in several ground state transitions in /sup 235/U I using the multistep laser photoionization method on an atomic beam. The instrumental linewidth was 300 to 400 MHz corresponding to a calculated residual Doppler width of approximately 300 MHz and a laser width of about 100 MHz. The technique also provides very accurate values (less than 100 MHz) for the isotope shifts for the investigated transitions.
Date: September 30, 1976
Creator: Paisner, J. A.; May, C. A.; Carlson, L. R.; Worden, E. F.; Johnson, S. A. & Solarz, R. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Photo-Induced Spin-State Conversion in Solvated Transition Metal Complexes Probed via Time-Resolved Soft X-ray Spectroscopy

Description: Solution-phase photoinduced low-spin to high-spin conversion in the FeII polypyridyl complex [Fe(tren(py)3)]2+ (where tren(py)3 is tris(2-pyridylmethyliminoethyl)amine) has been studied via picosecond soft X-ray spectroscopy. Following 1A1 --> 1MLCT (metal-to-ligand charge transfer) excitation at 560 nm, changes in the iron L2- and L3-edges were observed concomitant with formation of the transient high-spin 5T2 state. Charge-transfer multiplet calculations coupled with data acquired on low-s… more
Date: April 30, 2010
Creator: Huse, Nils; Kim, Tae Kyu; Jamula, Lindsey; McCusker, James K.; de Groot, Frank M. F. & Schoenlein, Robert W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Physical Properties of Intermetallic FE2VA1

Description: Fe{sub 2}VAl has recently been discovered to have a negative temperature coefficient of resistivity, moderately enhanced specific heat coefficient, and a large DOS at the Fermi level by photoemission. This triggered a round of heated research to understand the ground state of this material, both theoretically and experimentally. here they report a comprehensive characterization of Fe{sub 2}VAl. X-ray diffraction exhibited appreciable antisite disorder in all of our samples. FTIR spectroscopy me… more
Date: May 30, 2002
Creator: Feng, Ye
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

The 75As(n,2n) Cross Sections into the 74As Isomer and Ground State

Description: The {sup 75}As(n, 2n) cross section for the population of the T{sub 1/2} = 26.8-ns isomer at E{sub x} = 259.3 keV in {sup 74}As has been measured as a function of incident neutron energy, from threshold to E{sub n} = 20 MeV. The cross section was measured using the GEANIE spectrometer at LANSCE/WNR. For convenience, the {sup 75}As(n, 2n) population cross section for the {sup 74}As ground state has been deduced as the difference between the previously-known (n, 2n) reaction cross section and the… more
Date: June 30, 2003
Creator: Younes, W.; Garrett, P. E.; Becker, J. A.; Bernstein, L. A.; Ormand, W. E.; Dietrich, F. S. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Thermal Neutron Capture Cross Sections of The Palladium Isotopes

Description: We have measured precise thermal neutron capture {gamma}-ray cross sections {sigma}{sub {gamma}} for all stable Palladium isotopes with the guided thermal neutron beam from the Budapest Reactor. The data were compared with other data from the literature and have been evaluated into the Evaluated Gamma-ray Activation File (EGAF)[1]. Total radiative neutron capture cross-sections {sigma}{sub 0} can be deduced from the sum of transition cross sections feeding the ground state of each isotope if th… more
Date: August 30, 2005
Creator: Firestone, R. B.; Krticka, M.; McNabb, D. P.; Sleaford, B.; Agvaanluvsan, U.; Belgya, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

GAMMASPHERE+FMA : a journey beyond the proton drip-line.

Description: The majority of experiments performed during the 2-year long stay of GAMMAS-PHERE at the Argonne National Laboratory aimed to study proton-rich nuclei far from the line of stability at and beyond the proton drip-line. A high reaction channel selectivity was required to assign in-beam {gamma}-ray transitions to weakly populated exotic nuclei in the presence of background from strong reaction channels. In many of the experiments this was achieved by using the Argonne fragment mass analyzer to sep… more
Date: November 30, 2000
Creator: Seweryniak, D.; Woods, P. J.; Ressler, J. J.; Davids, C. N.; Heinz, A.; Sonzogni, A. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen