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Ionization Thresholds of Small Carbon Clusters: Tunable VUVExperiments and Theory

Description: Small carbon clusters (Cn, n = 2-15) are produced in amolecular beam by pulsed laser vaporization and studied with vacuumultraviolet (VUV) photoionization mass spectrometry. The required VUVradiation in the 8-12 eV range is provided by the Advanced Light Source(ALS) at the Lawrence Berkeley National Laboratory. Mass spectra atvarious ionization energies reveal the qualitative relative abundances ofthe neutral carbon clusters produced. By far the most abundant species isC3. Using the tunability … more
Date: July 31, 2007
Creator: Belau, Leonid; Wheeler, Steven E.; Ticknor, Brian W.; Ahmed,Musahid; Leone, Stephen R.; Allen, Wesley D. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Experimental Techniques, Volume 1, Part 2: Ionization Chambers and Counters

Description: From foreword: "Construction of some typical ionization detectors and their operation, with most developed at the Los Alamos Laboratory and a few at other projects connected with the development of the atomic bomb." This report includes chapters 8-16 and an appendix to the second part.
Date: 1947
Creator: Rossi, Bruno Benedetto & Staub, Hans Heinrich
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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An Experimental and Theoretical Study on the Ionization Energies of Polyynes (H-(C = C)n-H; n = 1 - 9)

Description: We present a combined experimental and theoretical work on the ionization energies of polyacetylene -- organic molecules considered as important building blocks to form polycyclic aromatic hydrocarbons (PAHs) in the proto planetary nebulae such as of CRL 618. This set of astrophysical data can be utilized with significant confidence in future astrochemical models of photon-dominated regions and also of the proto planetary nebulae CRL 618. We recommend ionization energies of polyacetylenes from … more
Date: May 17, 2010
Creator: Kaiser, Ralf I.; Sun, Bian Jian; Lin, Hong Mao; Chang, Agnes H. H.; Mebel, Alexander M.; Kostko, Oleg et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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RF, Thermal and Structural Analysis of the 201.25 MHz MuonIonization Cooling Cavity

Description: A finite element analysis has been carried out to characterize the RF, thermal and structural behavior of the prototype 201.25 MHz cavity for a muon ionization cooling channel. A single ANSYS model has been developed to perform all of the calculations in a multi-step process. The high-gradient closed-cell cavity is currently being fabricated for the MICE (international Muon Ionization Cooling Experiment) and MUCOOL experiments. The 1200 mm diameter cavity is constructed of 6 mm thick copper she… more
Date: May 10, 2005
Creator: Virostek, S. & Li, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electronic structure and spectroscopy of nucleic acid bases: Ionization energies, ionization-induced structural changes, and photoelectron spectra

Description: We report high-level ab initio calculations and single-photon ionization mass spectrometry study of ionization of adenine (A), thymine (T), cytosine (C) and guanine (G). For thymine and adenine, only the lowest-energy tautomers were considered, whereas for cytosine and guanine we characterized five lowest-energy tautomeric forms. The first adiabatic and several vertical ionization energies were computed using equation-of-motion coupled-cluster method for ionization potentials with single and do… more
Date: August 2, 2010
Creator: Bravaya, Ksenia B.; Kostko, Oleg; Dolgikh, Stanislav; Landau, Arie; Ahmed, Musahid & Krylov, Anna I.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effect of microhydration on ionization energies of thymine

Description: A combined theoretical and experimental study of the effect of microhydration on ionization energies (IEs) of thymine is presented. The experimental IEs are derived from photoionization efficiency curves recorded using tunable synchrotron VUV radiation. The onsets of the PIE curves are 8.85+-0.05, 8.60+-0.05, 8.55+-0.05, and 8.40+-0.05 eV for thymine, thymine mono-, di-, and tri-hydrates, respectively. The computed (EOM-IP-CCSD/cc-pVTZ) AIEs are 8.90, 8.51, 8.52, and 8.35 eV for thymine and the… more
Date: January 3, 2011
Creator: Khistyev, Kirill; Bravaya, Ksenia B.; Kamarchik, Eugene; Kostko, Oleg; Ahmed, Musahid & Krylov, Anna I.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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STATUS OF THE INTERNATIONAL MUON IONIZATION COOLING EXPERIMENT(MICE)

Description: An international experiment to demonstrate muon ionization cooling is scheduled for beam at Rutherford Appleton Laboratory (RAL) in 2007. The experiment comprises one cell of the Study II cooling channel [1], along with upstream and downstream detectors to identify individual muons and measure their initial and final 6D phase-space parameters to a precision of 0.1%. Magnetic design of the beam line and cooling channel are complete and portions are under construction. The experiment will be desc… more
Date: July 18, 2007
Creator: Zisman, Michael S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Calorimetric Calibration of a Graphite Walled, Cavity-Type Ionization Chamber

Description: Technical report outlining cavity-type ionization chambers with graphite walls that are used to measure heat dissipation in the graphite reflector of the MTR mock-up. Studies the relationship between the ionization occurring in the chamber and the heat generated in the surrounding graphite medium. [From Abstract]
Date: January 23, 1951
Creator: Jenks, G. H.; Breazeale, W. M. & Hairston, J. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A theoretical study of the ground state and lowest excited states of PuO0/+/+2 and PuO20/+/+2

Description: The ground and excited states of neutral and cationic PuO and PuO2 have been studied with multiconfigurational quantum chemical methods followed by second order perturbation theory, the CASSCF/CASPT2 method. Scalar relativistic effects and spin-orbit coupling have been included in the treatment. As literature values for the ionization energy of PuO2 are in the wide range of ~;;6.6 eV to ~;;10.1 eV, a central goal of the computations was to resolve these discrepancies; the theoretical results in… more
Date: December 8, 2008
Creator: Gibson, John K.; La Macchia, Giovanni; Infante, Ivan; Gagliardi, Laura & Raab, Juraj
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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K-Shell Ionization Cross Sections of Selected Elements from Ag to La for Proton Bombardment from 0.6 to 2.0 MeV

Description: The K-shell x-ray and ionization cross sections are measured for protons on Ag, Cd, Sn, Sb, Te, Ba, and La over the ion energy range of 0.6 to 2.0 MeV. The data are compared to the predictions of the PWBA, the PWBA with corrections for binding energy and/or Coulomb deflection, the BEA, and the constrained BEA predictions. In general, the non-relativistic PWBA with binding energy correction gives the best overall agreement with the measurements of proton-induced x-ray processes for the K-shell o… more
Date: May 1974
Creator: Khelil, Najat Arafat
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Inner-shell electron spectroscopy and chemical properties of atoms and small molecules

Description: The program has been concerned with gas-phase carbon 1s photoelectron spectroscopy of a number of molecules of potential chemical interest. The primary goals have been to determine carbon 1s ionization energies with a view of relating these to other chemical properties such as electronegativity, acidity, basicity, and reactivity, in order to provide a better understanding of these fundamental properties. The role of electron-donating (methyl) and electron-withdrawing (fluoro) substituents on th… more
Date: January 21, 2009
Creator: Thomas, T. Darrah
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental Tests of Cooling: Expectations and Additional Needs

Description: Cooling is a critical aspect for a high-performance Neutrino Factory or a MuonCollider. For this reason, considerable effort is being put toward theexperimental verification of this technique. The international Muon IonizationCooling Experiment, MICE, was approved to operate at Rutherford AppletonLaboratory (RAL) in the UK and beam line commissioning commenced in March, 2008. The MICE collaboration comprises about 130 scientists and engineers from Asia, Europe, and the U.S. In this paper we pre… more
Date: September 24, 2008
Creator: Zisman, Michael S
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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K-Shell Ionization Cross Sections For Elements Se To Pd: 0.4 To 2.0 MeV

Description: K-Shell ionization cross section for protons over the energy range of 0.4 to 2.0 MeV have been measured on thin targets of the elements Se, Br, Rb, Sr, Y, Mo and Pd. Total x-ray and ionization cross sections for the K-shell are reported. The experimental values of the ionization cross sections are compared to the non-relativistic plane-wave Born approximation, the binary-encounter approximation, the constrained binary-encounter approximation, and the plane-wave Born approximation with correctio… more
Date: December 1974
Creator: Criswell, Tommy L.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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High Temperature Condensed Phase Mass Spectrometric Analysis

Description: This program (in the 20th month as of this writing) was initiated with the goal of designing, constructing and operating a materials analysis instrument capable of obtaining a wide variety of chemical measurements on a material at high temperature. This instrument is being built around a quadrupole mass spectrometer. There are three main modes of obtaining spectra from the high temperature condensed phase material; surface ionization from the condensed phase, secondary ion mass spectrometry (SI… more
Date: June 1, 1999
Creator: Delmore, James E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Absolute Yield of the Ferrous Sulfate Oxidation Reaction

Description: The absolute yield of the ferrous sulfate oxidation reaction, under the influence of ionizing radiation, has been determined. A polystyrene, parallel plate ionization chamber, filled with argon, nitrogen, or air, was used to measure the energy absorbed per unit volume of the solution through the application of the Bragg-Gray principle. The ionization current was extrapolated to zero chamber spacing. In related experiments the average ionization potential of polystyrene was determined to be 34.3… more
Date: unknown
Creator: Weiss, J.; Bernstein, W. & Kuper, J. B. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Direct Determination of the Ionization Energies of PtC, PtO, and PtO2 with VUVRadiation

Description: Photoionization efficiency curves were measured for gas-phase PtC, PtO, and PtO2 using tunable vacuum ultraviolet (VUV) radiation at the Advanced Light Source. The molecules were prepared by laser ablation of a platinum tube, followed by reaction with CH4 or N2O and supersonic expansion. These measurements providethe first directly measured ionization energy for PtC, IE(PtC) = 9.45 +- 0.05 eV. The direct measurement also gives greatly improved ionization energies for the platinum oxides, IE(PtO… more
Date: July 21, 2008
Creator: Citir, Murat; Metz, Ricardo B.; Belau, Leonid & Ahmed, Musahid
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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