NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Lifetime of the metastable 2P1/2 state of F-like Ar9+ isolated in a compact Penning trap
Published
Author(s)
Samuel M. Brewer, Joan M. Dreiling, Nicholas D. Guise, Shannon M. Hoogerheide, Aung Naing, Joseph N. Tan
Abstract
Multiple-ionized atoms can be captured at low energy in a compact Penning trap, allowing the isolation of a single charge state to measure the radiative lifetime of an atomic state that decays via weakly allowed transitions. Such a measurement is reported here for the radiative decay lifetime of the metastable 2P1/2 state in flourine-like Ar9+ wherein the n = 2 shell has only one vacancy (hole) in a 2p orbital. Highly-ionized atoms are extracted from an electron beam ion trap (EBIT) and guided into the ion capture apparatus. Upon capturing the Ar9+ ions, light from the magnetic-dipole (M1) transitions are detected with a photomultiplier tube (PMT) and counted with a multichannel scaler. Using this technique, the radiative lifetime of the metastable 2P1/2 state in Ar9+ 1s2 2s2 2p5 is measured to be Tau = 9.39 +/- 0.09 ms, with a 1% relative uncertainty.
Citation
Physical Review A (Atomic, Molecular and Optical Physics)
Brewer, S.
, Dreiling, J.
, Guise, N.
, Hoogerheide, S.
, Naing, A.
and Tan, J.
(2018),
Lifetime of the metastable <sup>2</sup>P<sub>1/2</sub> state of F-like Ar<sup>9+</sup> isolated in a compact Penning trap, Physical Review A (Atomic, Molecular and Optical Physics), [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=924512
(Accessed October 7, 2025)