Lifetime of the23P0state of He-like197

Magnetic-field- and hyperfine-induced P03−S01 transitions in Be- and Ne-like ions

“…A number of recent papers present rates of HITs [3,[12][13][14][15][16][17][18][19][20] in the absence of magnetic fields. For HIT, experimental and theoretical studies for He-like ions [21][22][23][24][25][26][27][28][29] and Ni-like Xe [15,[30][31][32] are in good agreement. The resulting rate for Be-like N by Brage et al [33], obtained by modeling of a planetary nebulae, are also in agreement with theory, albeit with fairly large experimental uncertainty.…”

Hyperfine quenching: review of experiment and theory1This review is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.

“…Table 2. It should be mentioned that the theoretical value shown in Table 2 contains corrections for the Bohr-Weisskopf effect [45] and for two-photon (E1M1) emission [46] as discussed in [19]. Decay of 3 P 2 states in He-like ions: For most of the He-like ions discussed earlier, the hyperfine induced contribution has given a small or negligible contribution to lifetimes of 3 P 2 states.…”

“…An experiment based on this idea was later carried out on isotopes of Ag by [14], leading to a value of E 10 in good agreement with theoretical predictions. • PT Aboussaïd et al [22] used perturbation theory to evaluate quenching rates for 3 P 0 states of the He-like ions 19 F , 23 Na, and 25 Al. The multi-configuration Hartree-Fock (MCHF) method with Breit-Pauli corrections was used to calculate energies, wave functions, and matrix elements.…”

“…• Engström et al [7,8] made beam-foil measurements of the lifetimes of the 3 P 0 and 3 P 2 levels of the He-like ion 19 [9] carried out beam-foil measurements of lifetimes of the 3 P 0 and 3 P 2 levels of the He-like ion 25 Al at the 6.4 MV EN Tandem Accelerator in Upsala. The measured lifetime of the 3 P 0 state, where quenching contributes 30% of the total, is seen in Table 2 to be in agreement with theory.…”

“…Pioneering beam-foil measurements by Gould et al [6] on hyperfine quenching in He-like V led to many measurements [7][8][9][10][11][12][13][14][15][16][17][18][19] and theoretical calculations [20][21][22][23][24] of quenching rates along the He isoelectronic sequence. Experimental lifetimes of (1s2p) 3 P 0 states along the He isoelectronic sequence differ from theoretical lifetimes by less than 10% typically.…”