Experimental determination of the ²⁴Mg I (3s3p)³P₂ lifetime.
We present the first experimental determination of the electric-dipole forbidden (3s3p)³P₂→(3s²)¹S₀ (M2) transition rate in ²⁴Mg and compare to state-of-the-art theoretical predictions. Our measurement exploits a magnetic trap isolating the sample from perturbations and a magneto-optical trap as an amplifier converting each ³P₂→¹S₀ decay event into millions of photons readily detected. The transition rate is determined to be (4.87 ± 0.3)×10⁻⁴  s⁻¹ corresponding to a ³P₂ lifetime of 2050(-110)(+140) sec. This value is in agreement with recent theoretical predictions, and to our knowledge the longest lifetime ever determined in a laboratory environment.
The Niels Bohr Institute, Universitetsparken 5, 2100 Copenhagen, Denmark.
B B
BB
Jensen
He
H
Ming
P G
PG
Westergaard
K
K
Gunnarsson
M H
MH
Madsen
A
A
Brusch
J
J
Hald
J W
JW
Thomsen