A5080677799- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Physics Studies
- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Ion-surface interactions and analysis
- Magnetic confinement fusion research
- Lipid Membrane Structure and Behavior
- Plasma Diagnostics and Applications
- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Laser-Matter Interactions and Applications
- Laser Design and Applications
- Particle accelerators and beam dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Spectroscopy and Laser Applications
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Analytical chemistry methods development
- Radioactive element chemistry and processing
- Photocathodes and Microchannel Plates
- Particle Accelerators and Free-Electron Lasers
- Luminescence Properties of Advanced Materials
University of Nevada, Reno
2011-2023
University of Rochester
2018
Energetics (United States)
2018
Nevada System of Higher Education
2014
Geophysical Laboratory
2010
Stanford University
2007
Lake Tahoe Community College
2004
Oak Ridge National Laboratory
2002
Absolute measurements of cross sections for photoionization a statistical admixture ${\mathrm{Ne}}^{+}$ in the ${}^{2}{P}_{3/2}^{o}$ ground state and ${}^{2}{P}_{1/2}^{o}$ metastable are reported energy range 40--71 eV at photon resolutions ranging from 22 meV to 2 meV. The experiments were performed using synchrotron radiation an undulator beamline Advanced Light Source with newly developed ion-photon-beam endstation. data characterized by multiple Rydberg series autoionizing resonances...
The objectives of this tutorial are as follows: 1) to help students and researchers develop a basic understanding how pulsed-power systems used create high-energy-density (HED) matter; 2) new, compact, efficient technology called linear transformer drivers (LTDs); 3) understand why LTDs an attractive for driving HED physics (HEDP) experiments; 4) contrast with the more traditional Marx-generator/pulse-forming-line approach HEDP 5) briefly review history LTD well some LTD-driven research...
Absolute cross-section measurements for valence-shell photoionization of Ar$^{+}$ ions are reported photon energies ranging from 27.4 eV to 60.0 eV. The data, taken by merging beams and synchrotron radiation at a energy resolution 10 meV, indicate that the primary ion beam was statistically weighted mixture $^2P^o_{3/2}$ ground state $^2P^o_{1/2}$ metastable Ar$^{+}$. Photoionization this C$\ell$-like is characterized multiple Rydberg series autoionizing resonances superimposed on direct...
High-resolution absolute experimental measurements and two independent theoretical calculations were performed for photoionization of O+ ions from the 2P(o) 2D(o) metastable levels 4S(o) ground state in photon energy range 30-35.5 eV. This is believed to be first comparison experiment theory reported states ions. While there correspondence between predicted measured positions relative strengths resonances, cross-section magnitudes fine structure are sensitive choice basis states.
Lifetimes for K-shell vacancy states in atomic carbon have been determined by measurement of the natural linewidth 1s → 2p photoexcited C + ions. The produced photoionization are identical to those photoexcitation a ion: 1s2s 2 22 D, P, and S autoionizing occur both cases. These stabilize emission an electron produce 2+ Measurements reported lifetime P :6 .3± 0.9 fs, 11.2 ± 1.1 fs 5.9 1.3 respectively. Knowledge such lifetimes is important comparative studies Kshell vacancies...
Abstract High‐pressure Fourier‐transform infrared absorption spectroscopy was used to study poly(methyl methacrylate) in a diamond anvil cell at pressures up ≈8 GPa. The positions of the vibrational modes were measured as function pressure. data analyzed determine mode Grüneisen parameters and bond anharmonicities. using models that include both volume independent dependent parameters, different compared. frequency shifts pressure found be consistent with those for similar types bonds other...
Absolute cross sections for the K-shell photoionization of ground-state Li-like carbon [C3+(1s22s 2S)] ions were measured by employing ion–photon merged-beams technique at Advanced Light Source. The energy ranges 299.8–300.15 eV, 303.29–303.58 eV and 335.61–337.57 [1s(2s2p)3P]2P, [1s(2s2p)1P]2P [(1s2s)3S 3p]2P resonances, respectively, investigated using resolving powers up to 6000. autoionization linewidth resonance was be 27 ± 5 meV compares favourably with a theoretical result 26 obtained...
Absolute total electron-ion recombination rate coefficients of argonlike ${\mathrm{Sc}}^{3+}{(3s}^{2}{3p}^{6})$ ions have been measured for relative energies between electrons and ranging from 0 to 45 eV. This energy range comprises all dielectronic resonances attached $3\stackrel{\ensuremath{\rightarrow}}{p}3d$ $3\stackrel{\ensuremath{\rightarrow}}{p}4s$ excitations. A broad resonance with an experimental width $0.89\ifmmode\pm\else\textpm\fi{}0.07 \mathrm{eV}$ due the...
Abstract High‐pressure Fourier‐transform infrared absorption spectroscopy has been performed on polycarbonate, using a diamond anvil cell to produce pressures up ∼6 GPa. The frequencies of the vibrational modes have measured as function pressure. Individual mode Grüneisen parameters determined for six modes. data were fit models that included both volume‐dependent and ‐independent parameters. frequency shifts pressure found be consistent with those similar types bonds in other molecules. ©...
The electron affinity of lanthanum has been measured using laser photoelectron energy spectroscopy. This is the first measurement for and one measurements an a rare-earth series element. was to be . At least bound excited state also observed in spectra, binding relative ground as present experimental are compared recent calculation.
Absolute cross-section measurements for K-shell photoionization of Be-like C2+ ions have been performed in the photon energy range 292–325 eV. These made using photon–ion merged-beam endstation at Advanced Light Source, Lawrence Berkeley National Laboratory. compared with theoretical results from R-matrix method indicate that primary ion beam consisted 62% ground-state (1s22s2 1S) and 38% metastable state (1s22s2p 3Po) ions. Reasonable agreement is seen between theory experiment absolute...
Photoionization of Kr$^+$ ions was studied in the energy range from 23.3 eV to 39.0 at a photon resolution 7.5 meV. Absolute measurements were performed by merging beams and monochromatized synchrotron undulator radiation. (PI) this Br-like ion is characterized multiple Rydberg series autoionizing resonances superimposed on direct photoionization continuum. Resonance features observed experimental spectra are spectroscopically assigned their energies quantum defects tabulated. The...
The principle of microscopic time reversal physical processes, detailed balance, is widely used and depended upon in the theoretical community as a connection between photorecombination (PR) photoionization (PI). This paper reports on novel use balance comparison experimental results obtained by two very distinct techniques to determine both metastable fraction an ion beam partial Sc3+ PR cross sections Sc2+ PI for ground state states. system presents unique opportunity obtain comprehensive...
We have measured the total cross section for photodetachment of Na- ion over photon energy range 30-51 eV. Electron detachment leads predominantly to production Na+ ions in this range. The structures are associated with correlated processes involving or excitation a 2p core electron, which often accompanied by one more valence electrons. most prominent feature is strong resonance electron from and 3s electron. As previous experiments on double electrons, correlation seen play an important...
Cross sections for the photoionization (PI) of ${\mathrm{Sc}}^{2+}$ ions with $[\mathrm{Ar}]3d$ ground-state configuration have been measured by employing merged ion-photon beams method. The were produced from metallic vapor in an electron cyclotron resonance ion source, and photon beam was generated undulator electron-synchrotron storage ring advanced light source Lawrence Berkeley National Laboratory. experimental energy range 23--68 eV encompasses direct $3d$ $3p$ thresholds. photoion...
Measuring magnetic field and current distribution in Z-pinch plasma systems is crucial to the validation of theory. In this letter, demonstration proton deflectometry pulsed-power-driven loads at mega-amp scale presented, which capable making more detailed maps high-density regions plasmas. method, a laser-driven, broad-spectrum, MeV-energy beam directed through system, resulting deflections are measured examine configuration fields infer currents that support them. The technique was first...
Gas puff Z-pinches are intense sources of X-rays and neutrons but highly susceptible to the magneto-Rayleigh-Taylor instability (MRTI). MRTI mitigation is critical for optimal reproducible yields, motivating significant attention toward various potential mechanisms. One such approach external application an axial magnetic field, which will be discussed here in context recent experiments on Zebra generator (1 MA, 100 ns) at University Nevada, Reno. In these experiments, annular Kr gas liner...
Absolute photoionization cross sections have been measured for a mixture of ground-state and metastable O II (O+) ions at photon energies ranging from 29.9 to 46.0 eV (414.7 269.5 Å). All measurements were performed by merging an O+ beam with synchrotron radiation undulator line the Advanced Light Source (ALS). At resolution 17 meV, more than 70 spectral features resolved, most them identified characterized. These are compared two independent R-matrix calculations data in TOPbase. three...
Abstract The investigation of phase transitions and associated changes in the conformational order lipids is importance various research areas dealing with phenomena such as formation fusion vesicles, transmembrane diffusion membrane interactions drugs proteins. In this article, we have focused on study thermotropic behaviors two newly developed synthetic PEGylated trademarked QuSomes. contrast to conventional phospholipids, new kind lipid forms liposomes spontaneously upon hydration,...
Photoionization of Cl III ions into IV was studied theoretically using the ab initio relativistic Breit–Pauli R-matrix (BPRM) method and experimentally at Advanced Light Source (ALS) synchrotron Lawrence Berkeley National Laboratory. A relative-ion-yield spectrum measured with a photon energy resolution 10 meV. The theoretical study carried out large wave-function expansion 45 levels configurations 3s23p2, 3s3p3, 3s23p3d, 3s23p4s, 3s3p23d, 3p4. resulting spectra are complex. We have compared...
Evidence of odd-numbered Cn2− (n=7–13) cluster beams produced in a cesium-sputter negative ion source has been observed. The minimum lifetime smallest dianion, C72−, is estimated to be at least 55 μs. An experiment investigate the structure these dianions also described.
Recent experiments on the 1 MA, 100 ns Zebra driver at Nevada Terawatt Facility University of Nevada, Reno, investigated compression a deuterium target by high-atomic-number (Ar or Kr) gas-puff liner. Pinch stability improved with axial premagnetization 1–2 kG observed as decrease in magneto-Rayleigh-Taylor instability growth. Implosion dynamics and stagnation conditions were studied computationally radiation-MHD code MACH2 using initial that approximate those experiment. Typical average...
We report the first experimental determination of electron affinity gallium. The experiment was performed using laser photodetachment spectrometry technique. Photoelectron kinetic energy spectra from and were used to calibrate scale for photoelectron spectra. determined be . This measurement is compared several recent calculations