0000000000613854
AUTHOR
Ch. Gerz
showing 5 related works from this author
Lifetime of the metastable 6P 3/2 level of PbII
1989
Pb+-ions were stored in a r.f.-quadrupole trap. Short laser pulses at a 710-nm M1-transition excited the ions to the metastable 6P 3/2 level. Time-resolved registration of the subsequent decay photons at the same wavelength directly gives the lifetime of that state. No dependence of the decay rate on the density of different buffer gases up to 10−5 mbar pressure was observed and from this we deduced upper limits to the quenching cross section. We have observed, however, a small dependence on the stored ion number. The final result for the lifetime is 41.2 ± 0.7 ms in agreement with the result of a previous calculation.
Lifetime of the 4D 3/2 and 4D 5/2 metastable states in Sr II
1987
Sr+ ions were confined in a r.f. quadrupole trap for times of the order of 30 min. The metastable 4D states were populated via laser excitation of the 5P states. The weak quadrupole transition rate into the 5S 1/2 ground state at 674 and 687 nm was deduced from observation of the exponential decay. At background pressures above 10−7 mbar the radiative decay is dominated by collisional quenching. Extrapolation of the observed decay rate to zero background pressure yields the radiative lifetimes. At pressures around 10−6 mbar fine structure mixing collisions between the 4D states have been observed, which lead to corrections of the extrapolated lifetimes. As the final result we obtain 395±38 …
Precise ground-state hyperfine splitting inii173
1987
A laser-microwave double-resonance experiment on electrodynamically trapped $^{173}\mathrm{Yb}^{+}$ ions has been performed and a value of \ensuremath{\Delta}${\ensuremath{\nu}}_{\mathrm{h}\mathrm{f}\mathrm{s}=10\phantom{\rule{0ex}{0ex}}491\phantom{\rule{0ex}{0ex}}720239.55}$\ifmmode\pm\else\textpm\fi{}0.09 Hz for the ground-state hyperfine separation has been determined. This value is corrected for small Zeeman and second-order Doppler shifts. Combined with a previous similar measurement on $^{171}\mathrm{Yb}^{+}$ and with the known ${g}_{I}$ values of both isotopes, we obtain a value of -0.004 25(6) for the differential hyperfine anomaly $^{171}\mathrm{\ensuremath{\Delta}}^{173}$.
Measurement of the4He-D2 mass difference
1990
A Penning ion trap spectrometer has been used to measure the modified cyclotron frequencies of trapped4He+ and D 2 + ions. The resonances were detected by a time of flight method after ejection of the ions from the trap. We obtain a mass differenceΔm (D2-4He) = 25600331(5)·10−9 amu in acordance with published values but with a reduced uncertainty.
Lifetime and collisional depopulation of the metastable 5D 3/2-state of Yb+
1988
The lifetime and collisional depopulation rates of the metastable 5D 3/2 state of Yb+ have been determined in a radiofrequency ion trap by observation of the fluorescence count rate after ion excitation by a short laser pulse. From measurements using He, N2 and H2 as buffer gases between 10−8 and 10−6 mbar pressure and linear extrapolation to zero pressure we obtain a lifetime of τ=52.15±1.00 ms and rate constants ofR(H2)=(1.02±0.10)×10−9 cm3/s andR(N2)=(1.78±0.19)×10−10 cm3/s. The lifetime is in fair agreement with a calculated value of 74 ms.