  We use a novel technique to solvate silver cations in small clusters of noble
gases. The technique involves formation of large, superfluid helium
nanodroplets that are subsequently electron ionized, mass-selected by
deflection in an electric field, and doped with silver atoms and noble gases
(Ng) in pickup cells. Excess helium is then stripped from the doped
nanodroplets by multiple collisions with helium gas at room temperature,
producing cluster ions that contain no more than a few dozen noble gas atoms
and just a few (or no) silver atoms. Under gentle stripping conditions helium
atoms remain attached to the cluster ions, demonstrating their low vibrational
temperature. Under harsher stripping conditions some of the heavier noble gas
atoms will be evaporated as well, thus enriching stable clusters Ng$_n$Ag$_m^+$
at the expense of less stable ones. This results in local anomalies in the
cluster ion abundance which is measured in a high-resolution time-of-flight
mass spectrometer. Based on these data we identify specific "magic" sizes n of
particularly stable ions. There is no evidence though for enhanced stability of
Ng$_2$Ag$^+$, in contrast to the high stability of Ng$_2$Au$^+$ that derives
from the covalent nature of the bond for heavy noble gases. "Magic" sizes are
also identified for Ag$_2^+$ dimer ions complexed with He or Kr. Structural
models will be tentatively proposed. A sequence of magic numbers $n$ = 12, 32,
44, indicative of three concentric solvation shells of icosahedral symmetry, is
observed for He$_n$H$_2$O$^+$.
