K-shell spectroscopy of Au plasma generated with a short-pulse laser1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (5) ◽  
pp. 647-651 ◽  
Author(s):  
C. Zulick ◽  
F. Dollar ◽  
H. Chen ◽  
K. Falk ◽  
G. Gregori ◽  
...  
Keyword(s):  
Short Pulse ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Laser System ◽  
Oscillator Strengths ◽  
X Rays ◽  
Plasma Diagnostic ◽  
International Colloquium ◽  
X Ray ◽  
Population Distributions

The production of X-rays from electron transitions into K-shell vacancies (Kα,β) emission) is a well-known process in atomic physics and has been extensively studied as a plasma diagnostic in low- and mid-Z materials. However, X-ray spectra from near neutral high-Z ions are very complex, and their interpretation requires the use of state-of-the-art atomic calculations. In this experiment, the Titan laser system at Lawrence Livermore National Laboratory was used to deliver an approximately 350 J laser pulse, with a 10 ps duration and a wavelength of 1054 nm, to a gold (Au) target. A transparent bent quartz crystal spectrometer with a hard X-ray energy window, ranging from 17 to 102 keV, was used to measure the emission spectrum. Kα1,α2 and Kβ1,γ1 transitions were observed over a range of target sizes. Additionally, a series of shots were conducted with a pre-ionizing long pulse (3 ns, 1–10 J, 527 nm) on the backside of the target. FLYCHK, an atomic non-LTE code, designed to provide ionization and population distributions, was used to model the experiment. Kα/Kβ ratios were found to be in good agreement with the predicted value for room temperature Au targets.

scholarly journals Microcoulomb (0.7 ± $$\frac{0.4}{0.2}$$ μC) laser plasma accelerator on OMEGA EP

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. L. Shaw ◽  
M. A. Romo-Gonzalez ◽  
N. Lemos ◽  
P. M. King ◽  
G. Bruhaug ◽  
...  
Keyword(s):  
Laser Plasma ◽  
Electron Beams ◽  
Laser Energy ◽  
Short Pulse ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
High Energy ◽  
High Energy Density ◽  
X Ray ◽  
Omega Laser

AbstractLaser-plasma accelerators (LPAs) driven by picosecond-scale, kilojoule-class lasers can generate particle beams and x-ray sources that could be utilized in experiments driven by multi-kilojoule, high-energy-density science (HEDS) drivers such as the OMEGA laser at the Laboratory for Laser Energetics (LLE) or the National Ignition Facility at Lawrence Livermore National Laboratory. This paper reports on the development of the first LPA driven by a short-pulse, kilojoule-class laser (OMEGA EP) connected to a multi-kilojoule HEDS driver (OMEGA). In experiments, electron beams were produced with electron energies greater than 200 MeV, divergences as low as 32 mrad, charge greater than 700 nC, and conversion efficiencies from laser energy to electron energy up to 11%. The electron beam charge scales with both the normalized vector potential and plasma density. These electron beams show promise as a method to generate MeV-class radiography sources and improved-flux broadband x-ray sources at HEDS drivers.

Spectroscopic analysis and modeling of tungsten EBIT and Z-pinch plasma experiments1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (5) ◽  
pp. 599-608 ◽  
Author(s):  
G.C. Osborne ◽  
A.S. Safronova ◽  
V.L. Kantsyrev ◽  
U.I. Safronova ◽  
P. Beiersdorfer ◽  
...  
Keyword(s):  
Electron Beam ◽  
Charge State ◽  
Ion Trap ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Oscillator Strengths ◽  
Charge Balance ◽  
International Colloquium ◽  
Pinch Plasma ◽  
Z Pinch

Spectral tungsten data taken on an electron beam ion trap (EBIT) at Lawrence Livermore National Laboratory are analyzed between 3 and 8 Å for electron beam energies between 2.5 and 4.1 keV. The advantage of using charge state balancing with the experimental EBIT spectra for the identification of lines is employed and discussed. Theoretical Hebrew University Lawrence Livermore Atomic Code (HULLAC) modeling is then benchmarked against the experimental EBIT results. In particular, Co-, Ni-, Zn-, Cu-, Ga-, and Ge-like transitions were modeled independently using HULLAC to aid in charge state balancing. This model is then compared with Z-pinch plasma data collected on Zebra, the 1.6 MA pulse power generator located in the Nevada Terawatt Facility at the University of Nevada, Reno. The model is used to calculate charge balance and average ionization levels of these experimental plasma results, with particular focus on planar tungsten arrays.

A visible spectral survey from the Alcator C-Mod tokamak1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (5) ◽  
pp. 615-626 ◽  
Author(s):  
A.T. Graf ◽  
M.J. May ◽  
P. Beiersdorfer
Keyword(s):  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Oscillator Strengths ◽  
Visible Emission ◽  
International Colloquium ◽  
10Th International Colloquium ◽  
Laboratory Plasmas ◽  
To Come ◽  
Low Charge ◽  
Spectral Survey

A visible spectral survey (3675–6744 Å) from the Alcator C-Mod tokamak has been performed using a high-resolution visible spectrometer constructed at the Lawrence Livermore National Laboratory. The Alcator C-Mod deuterium plasma is shown to have visible emission from numerous atomic species and low charge state ions including, D I, B II–III, B V, C II–III, N II–III, O II–IV, F II–III, Ne I, Na X, Al II–III, Si I–II, Cl II–III, Ar I–III, Ar X, Ti I and III, Fe I–III, Cu I, and III, Mo I, and W I. Nearly all of the emission is thought to come from the cooler edge of the plasma including the scrape-off layer, outside of the last closed magnetic flux surface. However, there is at least one example, included here, where intrinsic visible emission persists deeper into the plasma.

scholarly journals Characterization of a bright, tunable, ultrafast Compton scattering X-ray source

2004 ◽  
Vol 22 (3) ◽  
pp. 221-244 ◽  
Author(s):  
F.V. HARTEMANN ◽  
A.M. TREMAINE ◽  
S.G. ANDERSON ◽  
C.P.J. BARTY ◽  
S.M. BETTS ◽  
...  
Keyword(s):  
Electron Beam ◽  
Laser Pulse ◽  
Compton Scattering ◽  
Electron Beams ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
X Rays ◽  
Full Width ◽  
Half Maximum ◽  
X Ray

The Compton scattering of a terawatt-class, femtosecond laser pulse by a high-brightness, relativistic electron beam has been demonstrated as a viable approach toward compact, tunable sources of bright, femtosecond, hard X-ray flashes. The main focus of this article is a detailed description of such a novel X-ray source, namely the PLEIADES (Picosecond Laser–Electron Inter-Action for the Dynamical Evaluation of Structures) facility at Lawrence Livermore National Laboratory. PLEIADES has produced first light at 70 keV, thus enabling critical applications, such as advanced backlighting for the National Ignition Facility andin situtime-resolved studies of high-Zmaterials. To date, the electron beam has been focused down to σx= σy= 27 μm rms, at 57 MeV, with 266 pC of charge, a relative energy spread of 0.2%, a normalized horizontal emittance of 3.5 mm·mrad, a normalized vertical emittance of 11 mm·mrad, and a duration of 3 ps rms. The compressed laser pulse energy at focus is 480 mJ, the pulse duration 54 fs Intensity Full Width at Half-Maximum (IFWHM), and the 1/e2radius 36 μm. Initial X rays produced by head-on collisions between the laser and electron beams at a repetition rate of 10 Hz were captured with a cooled CCD using a CsI scintillator; the peak photon energy was approximately 78 keV, and the observed angular distribution was found to agree very well with three-dimensional codes. The current X-ray dose is 3 × 106photons per pulse, and the inferred peak brightness exceeds 1015photons/(mm2× mrad2× s × 0.1% bandwidth). Spectral measurements using calibrated foils of variable thickness are consistent with theory. Measurements of the X-ray dose as a function of the delay between the laser and electron beams show a 24-ps full width at half maximum (FWHM) window, as predicted by theory, in contrast with a measured timing jitter of 1.2 ps, which contributes to the stability of the source. In addition,K-edge radiographs of a Ta foil obtained at different electron beam energies clearly demonstrate the γ2-tunability of the source and show very good agreement with the theoretical divergence-angle dependence of the X-ray spectrum. Finally, electron bunch shortening experiments using velocity compression have also been performed and durations as short as 300 fs rms have been observed using coherent transition radiation; the corresponding inferred peak X-ray flux approaches 1019photons/s.

Kα transition probabilities for platinum and uranium ions for possible X-ray biomedical applications1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (5) ◽  
pp. 483-494 ◽  
Author(s):  
Sultana N. Nahar ◽  
Anil K. Pradhan ◽  
Sara Lim
Keyword(s):  
Radiative Decay ◽  
Transition Probabilities ◽  
High Energy ◽  
Decay Rates ◽  
Oscillator Strengths ◽  
X Rays ◽  
International Colloquium ◽  
X Ray ◽  
Enhanced Production ◽  
Uranium Ions

Platinum compounds, such as cisplatin and other high-Z materials, are increasingly common in biomedical applications. The absorption and emission of high-energy X-rays can occur via the 1s–2p Kα transitions in ions of heavy elements involving deep inner-shells. Oscillator strengths (f), line strengths (S), and radiative decay rates (A), for the 1s–2p transitions for the nine ionic states from hydrogen-like to fluorine-like, are presented for platinum and uranium. For platinum ions the Kα transitions are found to be in the hard X-ray region, 64–71 keV (0.18–0.17 Å), and for uranium ions they are in the range 94–105 keV (0.12–0.13 Å). Since the number of electrons in each ionic state of the element is different, the number of Kα transitions varies considerably. While there are two 1s–2p transitions (1s 2S1/2–2p [Formula: see text]) in H-like ions, there are 2, 6, 2, 14, 35, 35, and 14 transitions in He-like, Li-like, Be-like, B-like, C-like, N-like, and O-like ions, respectively, for a total of 112 Kα transitions for each element. These include both types of electric dipole (E1) allowed transitions, same-spin multiplicity and intercombination. The former dipole allowed transitions are in general strong; their radiative decay rates are of the order of A ∼ 1016 s–1. However, there are also many weaker transitions. We demonstrate the importance of these Kα transitions, as they appear as resonances in photo-ionization, which is relevant to the enhanced production of Auger electrons for possible radiation diagnostics and therapy.

Tungsten spectroscopy at the Livermore electron beam ion trap facility1This review is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

2011 ◽  
Vol 89 (5) ◽  
pp. 571-580 ◽  
Author(s):  
J. Clementson ◽  
P. Beiersdorfer ◽  
G.V. Brown ◽  
M.F. Gu ◽  
H. Lundberg ◽  
...  
Keyword(s):  
Electron Beam ◽  
Ion Trap ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Ion Traps ◽  
Oscillator Strengths ◽  
Radiative Properties ◽  
Experimental Investigations ◽  
Fusion Plasma ◽  
International Colloquium

The utilization of tungsten spectroscopy for diagnostics of magnetically confined fusion plasmas requires the radiative properties of tungsten ions to be accurately known. At the Lawrence Livermore National Laboratory, a program to gather spectroscopic data on tungsten ions has been initiated with the purpose to study spectral signatures and identify candidate fusion plasma diagnostics. In this paper, an overview of recent results from the Livermore WOLFRAM spectroscopy project is presented, which includes experimental investigations at the EBIT-I and SuperEBIT electron beam ion traps. In particular, the spectra of highly charged M- and L-shell tungsten ions have been studied. These investigations cover energy measurements of n = 2 to n = 2, 3 transitions in Ne-like W64+ through Li-like W71+ ions and soft X-ray measurements of n = 3 to n = 3, 4 transitions in M-shell ions with emphasis on the Ni-like W46+ and Si-like W60+ through Na-like W63+ ions. The measurements are complemented by atomic-structure calculations and spectral modeling using the Flexible Atomic Code (FAC).

Short wavelength x‐ray laser research at the Lawrence Livermore National Laboratory

1992 ◽  
Vol 4 (7) ◽  
pp. 2326-2337 ◽  
Author(s):  
B. J. MacGowan ◽  
L. B. Da Silva ◽  
D. J. Fields ◽  
C. J. Keane ◽  
J. A. Koch ◽  
...  
Keyword(s):  
Short Wavelength ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
X Ray

scholarly journals X-Ray Holography at Lawrence Livermore National Laboratory

1992 ◽  
pp. 255-258
Author(s):  
J. Trebes ◽  
C. Annese ◽  
D. Birdsall ◽  
J. Brase ◽  
J. Gray ◽  
...  
Keyword(s):  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
X Ray

First X-Ray Microprobe and Microspectroscopy Results From The Gsecars Sector At The Advanced Photon Source

1997 ◽  
Vol 3 (S2) ◽  
pp. 905-906
Author(s):  
Mark L. Rivers ◽  
Stephen R. Sutton ◽  
Peter Eng ◽  
Matthew Newville
Keyword(s):  
National Laboratory ◽  
Argonne National Laboratory ◽  
Third Generation ◽  
X Rays ◽  
Environmental Sciences ◽  
X Ray ◽  
State Determination ◽  
X Ray Absorption ◽  
The Magnetic Field ◽  
Photon Source

The Advanced Photon Source (APS) at Argonne National Laboratory is a third-generation synchrotron x-ray source, optimized for producing x-rays from undulators. Such undulator sources provide extremely bright, quasi-monochromatic radiation which is ideal for an x-ray microprobe. Such microprobes can be used for trace element quantification with x-ray fluorescence, or for chemical state determination with x-ray absorption spectroscopy. The GeoSoilEnviroCARS (GSECARS) sector at the APS is building an x-ray microprobe for research in earth, planetary, soil and environmental sciences.The GSECARS undulator source is a standard APS Undulator “A” which is a 3.3 cm period device with 72 periods. The energies of the undulator peaks can be varied by adjusting the gap, and hence the magnetic field of the undulator. The energy of the first harmonic can be varied in this way from approximately 3.1 keV to 14 keV. A measured undulator spectrum is shown in Figure 1.

scholarly journals The National Ignition Facility: the path to a carbon-free energy future

2012 ◽  
Vol 370 (1973) ◽  
pp. 4115-4129 ◽  
Author(s):  
Christopher J. Stolz
Keyword(s):  
Free Energy ◽  
Basic Science ◽  
Lawrence Livermore National Laboratory ◽  
Fusion Energy ◽  
National Laboratory ◽  
Laser System ◽  
Energy Gain ◽  
Laser Fusion ◽  
National Ignition Facility ◽  
Thermonuclear Ignition

The National Ignition Facility (NIF), the world's largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory. The NIF will enable exploration of scientific problems in national strategic security, basic science and fusion energy. One of the early NIF goals centres on achieving laboratory-scale thermonuclear ignition and energy gain, demonstrating the feasibility of laser fusion as a viable source of clean, carbon-free energy. This talk will discuss the precision technology and engineering challenges of building the NIF and those we must overcome to make fusion energy a commercial reality.

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