Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Physics B Atomic Molecular and Optical Physics

Electron-impact broadening of Sr+lines in ultracold neutral plasmas

D. Vrinceanu, H. R. Sadeghpour, Klaus Bartschat

Published Nov 9, 2004• 4 citations
Publisher

Abstract

We report on calculations of electron-impact broadening of Sr + spectral lines in ultracold neutral plasmas. Optical absorption imaging of an ultracold Sr plasma has recently been used to infer detailed in situ information on the ion dynamics. We modify our recent treatment of collisional broadening in He metastable lines to the collision of electrons from Sr + ions. The required scattering matrix elements are obtained from an ab initio R -matrix calculation.

DOI
10.1088/0953-4075/37/22/l02

Related papers

Electron-impact widths and shifts of Sr II lines in ultracold neutral plasmas

Bin Duan, Muhammad Abbas Bari, Zhifeng Wu +2 more

In this paper, we report on relativistic quantum-mechanical calculations of electron-impact linewidths and line shifts in singly ionized strontium ions in ultracold neutral plasmas. We have used the Dirac $R$-matrix methods to solve ($N+1$)-electron colliding systems and to generate the required scattering matrices. Calculated linewidths and line shifts at an electron density ${10}^{17}\phantom{\rule{0.16em}{0ex}}{\text{cm}}^{\ensuremath{-}3}$ and electron temperatures (several electronvolts) agree well with other theoretical calculations and are closer to the experimental observations. Our theoretical findings of linewidths and line shifts are almost twice as large as the earlier calculations for the particular selected plasma conditions. This work develops these quantum-mechanical procedures and applies them to the emission from ultracold neutral plasmas.

Physical Review A•Mar 11, 2013•4 citations

Ultracold neutral plasmas

T. C. Killian, Ying-Cheng Chen, Priya Gupta +6 more

Ultracold neutral plasmas are formed by photoionizing laser-cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral plasma physics. The electron temperature in these plasmas ranges from 1-1000 K and the ion temperature is around 1 K. The density can approach $10^{11}$ cm$^{-3}$. Fundamental interest stems from the possibility of creating strongly-coupled plasmas, but recombination, collective modes, and thermalization in these systems have also been studied. Optical absorption images of a strontium plasma, using the Sr$^+$ ${^2S_{1/2}} -> {^2P_{1/2}}$ transition at 422 nm, depict the density profile of the plasma, and probe kinetics on a 50 ns time-scale. The Doppler-broadened ion absorption spectrum measures the ion velocity distribution, which gives an accurate measure of the ion dynamics in the first microsecond after photoionization.

Plasma Physics and Controlled Fusion•Apr 20, 2005•5 citations

Optically Imaging an Ultracold Strontium Plasma

T. C. Killian

Ultracold neutral plasmas are formed by photoionizing laser‐cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral plasma physics. The electron temperature in these plasmas ranges from 1–1000 K and the ion temperature is around 1 K. The density can be as high as 1010 cm−3. Fundamental interest stems from the possibility of creating strongly‐coupled plasmas, but recombination, collective modes, and thermalization in these systems have also been studied. Optical absorption images of a strontium plasma, using the Sr+ 2S1/2 → 2P1/2 transition at 422 nm, depict the density profile of the plasma, and probe kinetics on a 50 ns time‐scale. The Doppler‐broadened ion absorption spectrum measures the ion velocity distribution, which gives an accurate measure of the ion dynamics in the first microsecond after photoionization.

AIP conference proceedings•Jan 1, 2005•0 citations

Using Absorption Imaging to Study Ion Dynamics in an Ultracold Neutral Plasma

Clayton E. Simien, Ying-Cheng Chen, Priya Gupta +5 more

We report optical absorption imaging of ultracold neutral strontium plasmas. The ion absorption spectrum determined from the images is Doppler broadened and thus provides a quantitative measure of the ion kinetic energy. For the particular plasma conditions studied, ions heat rapidly as they equilibrate during the first 250 ns after plasma formation. Equilibration leaves ions on the border between the weakly coupled gaseous and strongly coupled liquid states. On a longer time scale of microseconds, pressure exerted by the trapped electron gas accelerates the ions radially.

arXiv:physics/0310017•Physical Review Letters•Apr 6, 2004•160 citations

Absorption imaging and spectroscopy of ultracold neutral plasmas

T. C. Killian, Ying-Cheng Chen, Priya Gupta +6 more

Absorption imaging and spectroscopy can probe the dynamics of an ultracold neutral plasma during the first few microseconds after its creation. Quantitative analysis of the data, however, is complicated by the inhomogeneous density distribution, expansion of the plasma, and possible lack of global thermal equilibrium for the ions. In this article we describe methods for addressing these issues. Using simple assumptions about the underlying temperature distribution and ion motion, the Doppler-broadened absorption spectrum obtained from plasma images can be related to the average temperature in the plasma.

arXiv:physics/0407138•Journal of Physics B Atomic Molecular and Optical Physics•Jan 6, 2005•26 citations

Early time properties of ultracold neutral plasmas

Kelsie Niffenegger, K A Gilmore, F. Robicheaux

We present simulations of some of the early time properties of ultracold neutral plasmas. We focus on three aspects of this system. First, we study the earliest electron dynamics when the initial temperature of the electrons would place them in the strongly coupled regime. We focus on times out to ∼10 plasma periods of the electron but also present results out to ∼85 plasma periods. In particular, we study how the formation of Rydberg atoms leads to heating and how the mass of the ion could enter the dynamics. Second, we study how the ions behave when the electrons are at high temperatures by comparing simulations that treat the electrons as a fluid and simulations that simultaneously include the electrons and ions. For light ions, the electron–ion scattering transfers substantial energy from the electrons to the ions. Finally, we study the ion motion at early times and at low temperatures where the electron evolution and ion motion could be at comparable time scales. This allows a test of electron–ion scattering when the electron plasma is nearly strongly coupled and we find that the recent values for the electron–ion scattering rate underestimate the ion heating in our calculations.

Journal of Physics B Atomic Molecular and Optical Physics•Jun 29, 2011•20 citations
We report on calculations of electron-impact broadening of Sr + spectral lines in ultracold neutral plasmas. Optical absorption imaging of an ultracold Sr plasma has recently been used to infer detailed in situ information on the ion dynamics. We modify our recent treatment of collisional broadening in He metastable lines to the collision of electrons from Sr + ions. The required scattering matrix elements are obtained from an ab initio R -matrix calculation.
In this paper, we report on relativistic quantum-mechanical calculations of electron-impact linewidths and line shifts in singly ionized strontium ions in ultracold neutral plasmas. We have used the Dirac RRR-matrix methods to solve (N+1N+1N+1)-electron colliding systems and to generate the required scattering matrices. Calculated linewidths and line shifts at an electron density ${10}^{17}\phantom{\rule{0.16em}{0ex}}{\text{cm}}^{\ensuremath{-}3}$ and electron temperatures (several electronvolts) agree well with other theoretical calculations and are closer to the experimental observations. Our theoretical findings of linewidths and line shifts are almost twice as large as the earlier calculations for the particular selected plasma conditions. This work develops these quantum-mechanical procedures and applies them to the emission from ultracold neutral plasmas.
Ultracold neutral plasmas are formed by photoionizing laser-cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral plasma physics. The electron temperature in these plasmas ranges from 1-1000 K and the ion temperature is around 1 K. The density can approach 101110^{11}1011 cm−3^{-3}−3. Fundamental interest stems from the possibility of creating strongly-coupled plasmas, but recombination, collective modes, and thermalization in these systems have also been studied. Optical absorption images of a strontium plasma, using the Sr+^++ 2S1/2−>2P1/2{^2S_{1/2}} -> {^2P_{1/2}}2S1/2​−>2P1/2​ transition at 422 nm, depict the density profile of the plasma, and probe kinetics on a 50 ns time-scale. The Doppler-broadened ion absorption spectrum measures the ion velocity distribution, which gives an accurate measure of the ion dynamics in the first microsecond after photoionization.
Ultracold neutral plasmas are formed by photoionizing laser‐cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral plasma physics. The electron temperature in these plasmas ranges from 1–1000 K and the ion temperature is around 1 K. The density can be as high as 1010 cm−3. Fundamental interest stems from the possibility of creating strongly‐coupled plasmas, but recombination, collective modes, and thermalization in these systems have also been studied. Optical absorption images of a strontium plasma, using the Sr+ 2S1/2 → 2P1/2 transition at 422 nm, depict the density profile of the plasma, and probe kinetics on a 50 ns time‐scale. The Doppler‐broadened ion absorption spectrum measures the ion velocity distribution, which gives an accurate measure of the ion dynamics in the first microsecond after photoionization.
We report optical absorption imaging of ultracold neutral strontium plasmas. The ion absorption spectrum determined from the images is Doppler broadened and thus provides a quantitative measure of the ion kinetic energy. For the particular plasma conditions studied, ions heat rapidly as they equilibrate during the first 250 ns after plasma formation. Equilibration leaves ions on the border between the weakly coupled gaseous and strongly coupled liquid states. On a longer time scale of microseconds, pressure exerted by the trapped electron gas accelerates the ions radially.
Absorption imaging and spectroscopy can probe the dynamics of an ultracold neutral plasma during the first few microseconds after its creation. Quantitative analysis of the data, however, is complicated by the inhomogeneous density distribution, expansion of the plasma, and possible lack of global thermal equilibrium for the ions. In this article we describe methods for addressing these issues. Using simple assumptions about the underlying temperature distribution and ion motion, the Doppler-broadened absorption spectrum obtained from plasma images can be related to the average temperature in the plasma.
We present simulations of some of the early time properties of ultracold neutral plasmas. We focus on three aspects of this system. First, we study the earliest electron dynamics when the initial temperature of the electrons would place them in the strongly coupled regime. We focus on times out to ∼10 plasma periods of the electron but also present results out to ∼85 plasma periods. In particular, we study how the formation of Rydberg atoms leads to heating and how the mass of the ion could enter the dynamics. Second, we study how the ions behave when the electrons are at high temperatures by comparing simulations that treat the electrons as a fluid and simulations that simultaneously include the electrons and ions. For light ions, the electron–ion scattering transfers substantial energy from the electrons to the ions. Finally, we study the ion motion at early times and at low temperatures where the electron evolution and ion motion could be at comparable time scales. This allows a test of electron–ion scattering when the electron plasma is nearly strongly coupled and we find that the recent values for the electron–ion scattering rate underestimate the ion heating in our calculations.