Experimental determination of the single-photon transition rate between the 2 $sup 3$$S$$sub 1$ and 1 $sup 1$$S$$sub 0$ states of He I

Journal Article · Mon Dec 01 04:00:00 EST 1975 · Phys. Rev., A, v. 12, no. 6, pp. 2455-2463

OSTI ID:4084405

Woodworth, J R; Moos, H W

The highly forbidden single-photon transition rate between the 2 $sup 3$$S$$sub 1$ and 1 $sup 1$$S$$sub 0$ states of He I has been measured in a radio- frequency He discharge. The population of metastables in the 2 $sup 3$$S$$sub 1$ state was determined by Fabry-Perot interferometric profiles of absorption from the 2 $sup 3$$S$$sub 1$ to the 4 $sup 3$$P$$sub 0$$,$$sub 1$$,$$sub 2$ states. High spectral resolution and precision ultraviolet radiometry were used to determine the brightness of the emission feature observed at 625.54 +- 0.05 A, compared to the theoretical value of 625.56 A. Because of the very low transition rate, this feature is weak, but it is shown that it is due to the 2 $sup 3$$S$$sub 1$-1 $sup 1$$S$$sub 0$ transition. The value for the radiative transition rate obtained in these experiments was 1.10 x 10$sup -4$/sec, with a 2sigma uncertainty of +- 30%. A comparison to the theoretical value of 1.27 x 10$sup -4$/sec is given. The relevance of this work to the beam-foil experiments which have measured the 2 $sup 3$$S$$sub 1$-1 $sup 1$$S$$sub 0$ transition rate for high-Z He-like ions is also discussed. (AIP)

• Research Organization: Department of Physics, The Johns Hopkins University, Baltimore, Maryland 21218
• NSA Number: NSA-33-015613
• OSTI ID: 4084405
• Journal Information: Phys. Rev., A, v. 12, no. 6, pp. 2455-2463, Journal Name: Phys. Rev., A, v. 12, no. 6, pp. 2455-2463; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

*HELIUM-- FORBIDDEN TRANSITIONS
640302* --Physics Research--Atomic
Molecular & Chemical Physics--Atomic & Molecular Properties
DECAY
METASTABLE STATES
N60200* --Physics (Atomic & Molecular)--Atomic & Molecular Properties
S STATES
ULTRAVIOLET RADIATION