scholarly journals The role of EBIT in X-ray laser research

2008 ◽  
Vol 86 (1) ◽  
pp. 19-23 ◽  
Author(s):  
J Nilsen
Keyword(s):  
Cross Sections ◽  
Ion Trap ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Highly Charged Ions ◽  
Index Of Refraction ◽  
X Ray ◽  
History Of ◽  
Level Of Understanding ◽  
Charged Ions

In the early 1980s, the X-ray laser program required a new level of understanding and measurements of the atomic physics of highly charged ions. The electron beam ion trap (EBIT) was developed and built at Lawrence Livermore National Laboratory (LLNL) as part of the effort to understand and measure the cross sections and wavelengths of highly charged ions. This paper explains some of the early history of EBIT and how it was used to help develop X-ray lasers. EBIT’s capability was unique and some of the experimental results obtained over the years, related to X-ray lasers, will be shown. As X-ray lasers have now become a table-top tool, new areas of research that involve understanding the index of refraction in partially ionized plasmas will be discussed. In addition, new areas where EBIT may be able to further contribute will be suggested.PACS Nos.: 52.38.–r, 52.25.Os, 52.70.–m, 42.55.Vc, 07.60.Ly, 29.30.Kv, 31.15.–p

scholarly journals Cometary X-ray emission: theoretical cross sections following charge exchange by multiply charged ions of astrophysical interest

2008 ◽  
Vol 86 (1) ◽  
pp. 171-174 ◽  
Author(s):  
S Otranto ◽  
R E Olson ◽  
P Beiersdorfer
Keyword(s):  
Charge Exchange ◽  
Cross Sections ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Classical Trajectory ◽  
Astrophysical Interest ◽  
X Ray ◽  
Fitting Procedure ◽  
Classical Trajectory Monte Carlo ◽  
Charged Ions

The classical trajectory Monte Carlo (CTMC) method is used to calculate emission cross sections following charge exchange collisions involving highly charged ions of astrophysical interest and typical cometary targets. Comparison is made to experimental data obtained on the EBIT machine at Lawrence Livermore National Laboratory (LLNL) for O8+ projectiles impinging on different targets at a collision energy of 10 eV/amu. The theoretical cross sections are used together with ion abundances measured by the Advanced Composition Explorer as well as those obtained by a fitting procedure using laboratory emission cross sections to reproduce the X-ray spectrum of comet C/LINEAR S4 measured on 14 July 2001.PACS Nos.: 34.70+e, 32.30.Rj, 32.70.Fw, 95.30.Ky

Visible spectrum of highly charged ions: The forbidden optical lines of Kr, Xe, and Ba ions in the Ar I to Kr I isoelectronic sequence

2002 ◽  
Vol 80 (12) ◽  
pp. 1687-1700 ◽  
Author(s):  
J.R. Crespo López-Urrutia ◽  
P Beiersdorfer ◽  
K Widmann ◽  
V Decaux
Keyword(s):  
Electron Beam ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Visible Spectrum ◽  
Ion Traps ◽  
Highly Charged Ions ◽  
Excited Configuration ◽  
Experimental Conditions ◽  
Ion Cloud ◽  
Charged Ions

We present experimental data on visible transitions in highly charged ions observed in the Lawrence Livermore National Laboratory (LLNL) electron beam ion traps, including results from lines within the ground-state configuration and the first excited configuration. Measurements of lines produced by Kr (q = 11+ to 22+), Xe (q = 18+ to 35+), and Ba (q = 28+ to 36+) ions, corresponding mainly to 3sl 3pm 3dn configurations, were carried out. The ionization stages were determined experimentally by sweeping the electron beam energy over the ionization threshold of each species. We propose possible identifications for the lines with the help of simple atomic structure calculations. However, most observed lines remained unidentified, demonstrating that the understanding of visible spectra from highly charged ions, even if obtained under nearly "ideal" experimental conditions, is still in its infancy. These spectral data may be useful for the diagnostics of magnetically confined plasmas and may set the stage for future measurements of radiative lifetimes. In our experiments, we used the emission from visible lines to image the intersection of the electron beam with a beam of neutral atoms injected into the trap at a right angle as well as the ion cloud in the trap. Under some conditions, the diameter of the ion cloud may be an order of magnitude larger than that of the electron beam. PACS Nos.: 32.30Jc, 39.30+w, 52.59Rz

High-precision measurements in few-electron highly charged ions at the HeidelbergElectron Beam Ion Trap (EBIT)

2005 ◽  
Vol 83 (4) ◽  
pp. 387-393 ◽  
Author(s):  
J.R. Crespo López-Urrutia ◽  
J Braun ◽  
G Brenner ◽  
H Bruhns ◽  
I N Draganič ◽  
...  
Keyword(s):  
High Precision ◽  
Quantum Electrodynamics ◽  
Nuclear Physics ◽  
Ion Trap ◽  
Dielectronic Recombination ◽  
Highly Charged Ions ◽  
Precision Measurements ◽  
Excitation Energies ◽  
X Ray ◽  
Charged Ions

The research program at the Heidelberg Electron Beam Ion Trap (EBIT) has concentrated mainly on precision measurements relevant to quantum electrodynamics (QED) and nuclear physics. Spectroscopic measurements in the optical region have delivered the most accurate wavelengths ever reported for highly charged ions, extracting even isotopic shifts. The forbidden transitions of B-like Ar XIV and Be-like Ar XV ions were studied. They are especially interesting, since the QED contributions are as large as 0.2%. Improved atomic structure calculations allowed for the determination of their values with growing accuracy. The lifetimes of the corresponding metastable levels have also been measured with an uncertainty of less than 0.5% thus becoming sensitive to the influence of the bound electron anomalous magnetic moment, so far an almost experimentally unexplored QED effect. A new laser spectroscopic setup aims at facilitating future studies of the hyperfine structure of heavy hydrogenic ions. Through the study of the dielectronic recombination, information on rare processes, such as two-electron-one-photon transitions in Ar16+, or the interference effects between dielectronic and radiative recombination in Hg77+, and accurate values for the excitation energies of very heavy HCI have been obtained. A novel X-ray crystal spectrometer allowing absolute X-ray wavelength measurements in the range up to 15 keV with very high precision and reproducibility is currently used to study the Lyman series of H-like ions of medium-Z ions and the 2s–2p transitions of very heavy Li-like ions. PACS Nos.: 31.30.Jv, 32.80.Fb, 32.80.Dz, 32.30.Jv, 32.30.Rj, 95.30.Dr

scholarly journals A “brief” history of spectroscopy on EBIT

2008 ◽  
Vol 86 (1) ◽  
pp. 1-10 ◽  
Author(s):  
P Beiersdorfer
Keyword(s):  
Electron Beam ◽  
Light Source ◽  
Ion Trap ◽  
Highly Charged Ions ◽  
X Rays ◽  
Electron Beam Ion Trap ◽  
History Of ◽  
Twentieth Anniversary ◽  
Charged Ions

In the autumn of 1986, the first electron beam ion trap, EBIT, was put into service as a light source for the spectroscopy of highly charged ions. On the occasion of the twentieth anniversary of EBIT, we review its early uses for spectroscopy, from the first measurements of X-rays from L-shell xenon ions in 1986 to its conversion to SuperEBIT in 1992 and rebirth as EBIT-I in 2001. Together with their sibling, EBIT-II, these machines have been used at Livermore to perform a multitude of seminal studies of the physics of highly charged ions.PACS Nos.: 01.65.+g, 32.30.–r, 32.30,Rj, 39.10.+j

Electron-impact excitation cross-section measurements at EBITs from 1986 to 2006

2008 ◽  
Vol 86 (1) ◽  
pp. 55-71 ◽  
Author(s):  
H Chen ◽  
P Beiersdorfer
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Cross Sections ◽  
Ion Trap ◽  
Spectroscopic Properties ◽  
Highly Charged Ions ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Wide Range ◽  
Charged Ions

This paper reviews the electron-impact excitation (EIE) measurements at electron beam ion trap (EBIT) facilities in the last 20~years. EIE cross sections are important atomic parameters fundamental to understanding the spectroscopic properties of ions. The properties of an EBIT make it an ideal device to measure the EIE cross section of highly charged ions. As a matter of fact, a report of EIE measurement was among the first papers published on the first EBIT ever built, EBIT-I. Since then, a wide range of measurements have been performed for K-shell and L-shell highly charged ions of Ti, V, Cr, Mn, Fe, Xe, and Ba using a combination of crystal spectrometers and solid-state X-ray detectors. In the last few years, the measurements were extended to all strong Fe L-shell lines by using a 6 × 6 pixel array microcalorimeter.PACS Nos.: 32.30.Jc, 32.30.Rj, 34.50.Fa, 32.70.Cs

The study of X-ray M-shell spectra of W ions from the Lawrence Livermore National Laboratory Electron Beam Ion Trap

2004 ◽  
Vol 82 (11) ◽  
pp. 931-942 ◽  
Author(s):  
P Neill ◽  
C Harris ◽  
A S Safronova ◽  
S Hamasha ◽  
S Hansen ◽  
...  
Keyword(s):  
Electron Beam ◽  
Energy Range ◽  
Spectral Region ◽  
Ion Trap ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Spectral Features ◽  
X Ray ◽  
Electron Beam Ion Trap

M-shell spectra of W ions have been produced at the Lawrence Livermore National Laboratory EBIT-II electron beam ion trap-II at different energies of the electron beam. A survey has been performed at 2.4, 2.8, and 3.6 keV, and for steps in energy of 100 eV over the 3.9–4.6 keV energy range. The analysis of 11 W spectra has shown the presence of a wide variety of ionization stages from Se-like to Cr-like W; the appearances of these ionization stages correlate well with the energy of their production. The present paper focuses on the identification of 63 experimental features of W ions in a spectral region from 5 to 6 Å (1 Å = 10–10 m) using calculations with inclusion of all ionization stages matching this spectral region. The majority of lines in all spectra have been identified and assigned to the 4f → 3d and 4d → 3p transitions. This is the first work that lists a comprehensive identification of so many resolved spectral features of X-ray M-shell transitions in W ions recorded in such detail in the laboratory. PACS Nos.: 52.58.Lq,32.30.Rj,52.70.La

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