  Phase II of SIMPLE (Superheated Instrument for Massive ParticLe Experiments)
searched for astroparticle dark matter using superheated liquid
C$_{2}$ClF$_{5}$ droplet detectors. Each droplet generally requires an energy
deposition with linear energy transfer (LET) $\gtrsim$ 150 keV/$\mu$m for a
liquid-to-gas phase transition, providing an intrinsic rejection against
minimum ionizing particles of order 10$^{-10}$, and reducing the backgrounds to
primarily $\alpha$ and neutron-induced recoil events. The droplet phase
transition generates a millimetric-sized gas bubble which is recorded by
acoustic means. We describe the SIMPLE detectors, their acoustic
instrumentation, and the characterizations, signal analysis and data selection
which yield a particle-induced, "true nucleation" event detection efficiency of
better than 97% at a 95% C.L. The recoil-$\alpha$ event discrimination,
determined using detectors first irradiated with neutrons and then doped with
alpha emitters, provides a recoil identification of better than 99%; it differs
from those of COUPP and PICASSO primarily as a result of their different
liquids with lower critical LETs. The science measurements, comprising two
shielded arrays of fifteen detectors each and a total exposure of 27.77 kgd,
are detailed. Removal of the 1.94 kgd Stage 1 installation period data, which
had previously been mistakenly included in the data, reduces the science
exposure from 20.18 to 18.24 kgd and provides new contour minima of
$\sigma_{p}$ = 4.3 $\times$ 10$^{-3}$ pb at 35 GeV/c$^{2}$ in the
spin-dependent sector of WIMP-proton interactions and $\sigma_{N}$ = 3.6
$\times$ 10$^{-6}$ pb at 35 GeV/c$^{2}$ in the spin-independent sector. These
results are examined with respect to the fluorine spin and halo parameters used
in the previous data analysis.
