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

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 State-selective charge exchange cross sections in Be$$^{4+} -\hbox {H}(2\textit{lm})$$ collision based on the classical trajectory Monte Carlo method

2021 ◽  
Vol 75 (4) ◽  
Author(s):  
Iman Ziaeian ◽  
Károly Tőkési
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Energy Range ◽  
Charge Exchange ◽  
Cross Sections ◽  
Impact Energy ◽  
Classical Trajectory ◽  
Quantum Mechanical ◽  
Three Body ◽  
Classical Trajectory Monte Carlo

Abstract A three-body classical trajectory Monte Carlo method is used to calculate the nl state-selective charge exchange cross sections in $$\hbox {Be}^{\mathrm {4+}}+$$ Be 4 + + H(2lm) collisions in the energy range between 10 and 200 keV/amu. We present partial cross sections for charge exchange into $$\hbox {Be}^{\mathrm {3+}}$$ Be 3 + (nl) $$(\textit{nl} = 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f)$$ ( nl = 2 s , 2 p , 3 s , 3 p , 3 d , 4 s , 4 p , 4 d , 4 f ) states as a function of impact energy. Our results are compared with the previous classical and quantum-mechanical results. We show that the classical treatment can able to describe reasonably well the charge exchange cross sections. Graphic abstract

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

Analytical X-Ray Safety at Lawrence Livermore National Laboratory

1986 ◽  
Vol 30 ◽  
pp. 583-594
Author(s):  
P. L. Wallace
Keyword(s):  
Control System ◽  
Materials Science ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
National Average ◽  
Science Department ◽  
Safety Control ◽  
X Ray ◽  
Safety Procedures

In this report, we summarize over 30 years of analytical x-ray safety history at Lawrence Livermore National Laboratory (LLNL), and describe the safety procedures used in the operation of analytical x-ray equipment in the laboratories managed by the LLNL Chemistry and Materials Science Department (C&MSD). The present safety control system, which was developed by users of the equipment, has proven effective in keeping incidents at LLNL to a rate consistent with the national average.

scholarly journals Study of pure and mixed clustered noble gas puffs irradiated with a high intensity (7 × 1019 W/cm2) sub-ps laser beam and achievement of a strong X-ray flash in a laser-generated debris-free X-ray source

2019 ◽  
Vol 37 (03) ◽  
pp. 276-287
Author(s):  
K. A. Schultz ◽  
V. L. Kantsyrev ◽  
A. S. Safronova ◽  
V. V. Shlyaptseva ◽  
E. E. Petkov ◽  
...  
Keyword(s):  
Laser Beam ◽  
Noble Gas ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Experimental Parameter ◽  
Mixed Gas ◽  
Plasma Parameters ◽  
X Ray ◽  
Drastic Increase ◽  
Degree Of Anisotropy

AbstractWe present a broad study of linear, clustered, noble gas puffs irradiated with the frequency doubled (527 nm) Titan laser at Lawrence Livermore National Laboratory. Pure Ar, Kr, and Xe clustered gas puffs, as well as two mixed-gas puffs consisting of KrAr and XeKrAr gases, make up the targets. Characterization experiments to determine gas-puff density show that varying the experimental parameter gas-delay timing (the delay between gas puff initialization and laser-gas-puff interaction) provides a simple control over the gas-puff density. X-ray emission (>1.4 keV) is studied as a function of gas composition, density, and delay timing. Xe gas puffs produce the strongest peak radiation in the several keV spectral region. The emitted radiation was found to be anisotropic, with smaller X-ray flux observed in the direction perpendicular to both laser beam propagation and polarization directions. The degree of anisotropy is independent of gas target type but increases with photon energy. X-ray spectroscopic measurements estimate plasma parameters and highlight their difference with previous studies. Electron beams with energy in excess of 72 keV are present in the noble gas-puff plasmas and results indicate that Ar plays a key role in their production. A drastic increase in harder X-ray emissions (X-ray flash effect) and multi-MeV electron-beam generation from Xe gas-puff plasma occurred when the laser beam was focused on the front edge of the linear gas puff.

Sign in / Sign up

Export Citation Format

Share Document