A5028359557- Atomic and Molecular Physics
- Laser-induced spectroscopy and plasma
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Physics Studies
- X-ray Spectroscopy and Fluorescence Analysis
- Plasma Diagnostics and Applications
- Laser-Matter Interactions and Applications
- Magnetic confinement fusion research
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Diamond and Carbon-based Materials Research
- Muon and positron interactions and applications
- Quantum optics and atomic interactions
- Scientific Measurement and Uncertainty Evaluation
- Electron and X-Ray Spectroscopy Techniques
- Luminescence Properties of Advanced Materials
- Superconducting Materials and Applications
- High-pressure geophysics and materials
- Scientific Research and Discoveries
- Radioactive Decay and Measurement Techniques
- Laser Design and Applications
- Ionosphere and magnetosphere dynamics
- Electromagnetic Launch and Propulsion Technology
- Advanced Materials Characterization Techniques
- Photocathodes and Microchannel Plates
Azrieli College of Engineering Jerusalem
2005-2021
Hebrew University of Jerusalem
1994-2007
United States Naval Research Laboratory
1991-1992
Czech Academy of Sciences, Institute of Physics
1984-1989
Laboratoire Aimé Cotton
1987
Johns Hopkins University
1985
Israel Atomic Energy Commission
1984
view Abstract Citations (271) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Potential for Plasma Diagnostics from Stellar Extreme-Ultraviolet Observations Feldman, U. ; Mandelbaum, P. Seely, J. F. Doschek, G. A. Gursky, H. A description of the lines most abundant ions in EUV spectrum range 50-500 that have special diagnostic significance is presented. These are plasmas temperature 10 exp 5 to 7 K. Their utility determining temperature,...
We have measured the radiation from medium-charge-state ions of tungsten in spectral range 45 to 70 \AA{}. The were produced an electron beam ion trap (EBIT), and was observed using a 2-m grazing-incidence spectrometer. Operating EBIT with energies between 500 eV 4 keV allowed us sample charge states ranging I-like ${\mathrm{W}}^{21+}$ Cu-like ${\mathrm{W}}^{45+}.$ Lines Sr-like through observed; for As-like new lines identified. Analysis spectra is based on ab initio calculations...
Narrow (\ensuremath{\Delta}\ensuremath{\lambda}5 \AA{}), intense quasicontinuum bands, appearing in emission spectra of highly ionized rare-earth elements between 70 and 100 \AA{}, previously observed tokamaks laser-produced plasmas, have been obtained from a low-inductance vacuum spark. The bands shift toward shorter wavelengths with increasing atomic number Z. Using the unresolved transition array model, these are identified as primarily 4d-4f transitions Rh i to Rb i--like ions, although...
In the atomic central-field model, cancellation of some electric-dipole line strengths is a well known effect configuration mixings. The authors study their global effects on transition arrays. A crucial quantity wavenumber mu 1 centre gravity two arrays when upper or lower configurations mix. closed formula derived for difference delta Emix between values with and without mixing effects. Two experimental examples are presented. first one, value sufficient proof that one almost completely...
Abstract The consequences of tungsten (W) melting on divertor lifetime and plasma operation are high priority issues for ITER. Sustained controlled W-melting experiment has been achieved the first time in WEST a poloidal sharp leading edge an actively cooled ITER-like facing unit (PFU). A series dedicated power steady state discharges were performed to reach point tungsten. was exposed parallel heat flux about 100 MW.m −2 up 5 s providing melt phase 2 without noticeable impact (radiated...
X-ray spectra of highly ionized tungsten and neighbouring atoms (Tm, Yb, Hf, Ta, W, Re Pt) has been observed from laser produced plasmas in the λ = 6-9 A range. Beside prominent lines Ni I-like ions, belonging to Co I (3d9-3d84p), Cu (3d104s-3d94s4p, 3d104p-3d94p2) Zn ions (3d104s2-3d94s24p, 3d104s4p-3d94s4p2) have identified. Classification was based on isoelectronic sequence analysis comparison with ab-initio relativistic calculations. collisional-radiative model plasma is used show that...
The spectra of elements Y, Zr, Nb, Mo, Ru, Rh, Pd, and Ag in the 10–100-Å range were obtained from a high-power vacuum spark grazing-incidence high-resolution spectrograph. transitions 3d10–3d94p, 3d10–3d94f, 3d10–3d95p, 3d10–3d95f identified. agreement with ab initio relativistic calculations is good. relevance jj coupling scheme for level labeling discussed, as importance effects, by comparing other results on high-Z atoms (up to Pt).
Previously published theoretical formulas for the mean wavelengths and spectral widths of unresolved transition arrays are applied to transitions types $3{d}^{N+1}\ensuremath{-}3{d}^{N}4p$ $3{d}^{N+1}\ensuremath{-}3{d}^{N}4f$ observed in highly ionized spectra Mo Pd. Agreement with experiment is excellent opens way quantitative interpretation intensities.
Abstract The VUV emission of tungsten in WEST is measured by an absolutely calibrated grazing incidence spectrometer the Schwob–Fraenkel type, which can scan lower half plasma. We have analysed detected spectral lines range 120–140 Å and compared their behaviour with calculations published information. obtained unambiguous identification four intense well-resolved emitted W 42+ -W 45+ close to magnetic axis experiments. spectral-line brightnesses are used assess Tungsten density region. In...
A new type of quasi-continuous spectra femtosecond laser plasma in the vicinity multicharged H-like and He-like ion resonance lines were observed interpreted for first time. It is shown that such generated by hollow ions are caused super high density conditions provided a contrast pulse.
The broad, characteristic, pseudo-continua appearing in many spectra of highly ionized heavy atoms (5-8 Å) are interpreted as superpositions Spin-Orbit-Split Arrays, a particular case Unresolved Transition Arrays for which formulas have been published recently. They pertain to 3d-4f transitions isoelectronic Cu, Zn, Ga and Ge. Some individual lines belonging the Co sequence also identified. Effects departure from pure jj coupling discussed.
Using high-resolution x ray and extreme ultraviolet (EUV) spectrometry, the line emission of W28+ - W50+ ions was measured at Berlin Electron Beam Ion Trap (EBIT). Our study encompasses a wide range wavelengths (5-800 Å) includes observation electric magnetic dipole lines. The results our measurements are compared with predicted transition from ab initioatomic structure calculations.
Relativistic calculations of the dielectronic recombination (DR) cross section and rate coefficient for Ne-like tungsten $({\mathrm{W}}^{64+})$ in ground state ${2s}^{2}{2p}^{6}$ are performed. The DR contributions most important Na-like doubly excited configuration complexes, namely, ${(2s2p)}^{7}{3ln}^{\ensuremath{'}}{l}^{\ensuremath{'}}$ ${(n}^{\ensuremath{'}}=3--13)$ ${(2s2p)}^{7}{4l4l}^{\ensuremath{'}},$ calculated by level-by-level computations. Collisional transitions following...
Ab initio calculations of the total dielectronic recombination (DR) rate coefficients for ten ions along Ni I isoelectronic sequence in ground state (${\mathrm{Mo}}^{14+}$, ${\mathrm{Ag}}^{19+}$, ${\mathrm{Xe}}^{26+}$, ${\mathrm{Pr}}^{31+}$, ${\mathrm{Gd}}^{36+}$, ${\mathrm{Dy}}^{38+}$, ${\mathrm{Ta}}^{45+}$, ${\mathrm{Au}}^{51+}$, ${\mathrm{At}}^{57+}$, and ${\mathrm{U}}^{64+}$) have been performed using HULLAC computer code package. Resonant nonresonant stabilizing radiative transitions...
Excitation of inner-shell electrons into autoionizing levels followed by autoionization (EA) can enhance the total ionization rate. For ions isoelectronic to elements fourth row, present results show that enhancements be much more important than those previously calculated for preceding sequences. \ensuremath{\Delta}n=1 3d-4l excitations, which are dominant EA channels, considered here. Detailed computations rates were performed using relativistic distorted-wave method, and behavior rate...
Ab initio calculations of the rate coefficients for dielectronic recombination (DR) ten ions along Ni i isoelectronic sequence in ground state (${\mathrm{Mo}}^{14+}$, ${\mathrm{Ag}}^{19+}$, ${\mathrm{Xe}}^{26+}$, ${\mathrm{Pr}}^{31+}$, ${\mathrm{Gd}}^{36+}$, ${\mathrm{Dy}}^{38+}$, ${\mathrm{Ta}}^{45+}$, ${\mathrm{Au}}^{51+}$, ${\mathrm{At}}^{57+}$, and ${\mathrm{U}}^{64+}$) through Cu-like 3${\mathit{d}}^{9}$4ln\ensuremath{'}l\ensuremath{'} (n\ensuremath{'}=4,5) inner-shell excited...
Ab initio calculations of the total dielectronic recombination (DR) rate coefficient for Ar-like tungsten $({\mathrm{W}}^{56+})$ are performed using relativistic HULLAC code package based on parametric potential method. The high efficiency compared to other codes enables us perform extensive DR highly complex atomic systems such as tungsten. present work provides a general procedure computing coefficients multielectron high-$Z$ ions. This is applicable computations ions, well ions in...
Spectra of highly ionized praseodymium and dysprosium recorded from the Texas tokamak (TEXT) plasma have been analyzed in 50–250-Å range. The spectra contain high-intensity continuum bands region below 100 Å bright individual lines above this wavelength. Lines identified. highest ionization state reached 1-keV central electron temperature was Cu i-like Pr xxxi. composition is explained terms a new theoretical approach developed to treat large unresolved transition arrays. brightness compared...
Transitions of the types 3s23pk-3s3pk+1 and 3pk-3pk-13d are identified in spectra zirconium molybdenum ions isoelectronic with K I to Mg I. These elements were introduced into Princeton large torus (PLT) tokamak by laser blow-off technique their recorded 60-150 AA range using a time-resolving grazing incidence spectrography. Brightnesses observed lines given. should be useful for spectroscopic diagnostics other high-temperature fusion research plasmas. Difficulties related study complex...