This thesis presents and discusses the results of measurements of the intrinsic lifetimes of bound excited anionic states. The results are valuable for evaluation of different theoretical models and computation methods and are compared to calculations when available. The measurements were carried out at the DESIREE facility located in the AlbaNova University Center in Stockholm. The storage ring used is cryogenically cooled and has a very low residual gas density. Both of these features are needed for the storage of some bound excited anionic states, as blackbody radiation would otherwise photodetach the state. Residual gas density is the main limiting factor for storage lifetime in the presented measurements. The majority of the work has been in the development and refinement of the laser probing technique utilized for the measurements, which had to be adapted for each anion to account for the different time-domains and wavelengths required.

The published results was a radiative lifetime of 503±54 seconds for the 3p^{5 2}P_1/2 state in sulfur, 15.1±0.4 seconds for the 4s^{2 2}D_3/2 state in nickel and 2.54±0.10 seconds for the 5d¹⁰ 6s ²S_1/2 state in platinum. The radiative lifetime of the 5d⁹ 6s^{2 2}D_3/2 state in platinum could only be estimated to a range of 50 ms to 200 ms.

The intrinsic lifetime of the upper level in the bound-bound 3d(9) 4s(2) D-2(3/2) -> 3d(9) 4s(2) D-2(5/2) radiative transition in Ni- was measured to be 15.1 +/- 0.4 s. The experiment was performed at cryogenic temperatures in one of the ion-beam storage rings of the Double ElectroStatic Ion Ring ExpEriment facility at Stockholm University. The storage lifetime of the Ni- ion beam was measured to be close to 5 min at a ring temperature of 13 K.

The intrinsic radiative lifetimes of the 5d(10)6s(2)S(1/2) and 5d(9)6s(2) D-2(3/2) bound excited states in the platinum anion Pt- have been studied at cryogenic temperatures at the Double ElectroStatic Ion Ring Experiment (DESIREE) facility at Stockholm University. The intrinsic lifetime of the higher-lying 5d(10)6s S-2(1/2) state was measured to be 2.54 +/- 0.10 s, while only a lifetime in the range of 50-200 ms could be estimated for the 5d(9)6s(2) D-2(3/2) fine-structure level. The storage lifetime of the Pt- ion beam was measured to be a little over 15 min at a ring temperature of 13 K. The present study reports the lifetime of an atomic negative ion in an excited bound state with an electron configuration different from that of the ground state.

We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the 3p 5  P 2  o 1/2 →3p 5  P 2  o 3/2   spontaneous radiative decay in S −  32   to be 503±54  sec . This is by orders of magnitude the longest lifetime ever measured in a negatively charged ion. Cryogenic cooling of the storage ring gives a residual-gas pressure of a few times 10 −14   mbar at 13 K and storage of 10 keV sulfur anions for more than an hour. Our experimental results differ by 1.3σ  from the only available theoretical prediction.