  Searches for supersymmetric particles in channels with one or more photons
and missing energy have been performed with data collected by the ALEPH
detector at LEP. The data consist of 11.1 pb-1 at $\sqrt{s} = 161 GeV$, 1.1
pb-1 at 170 GeV and 9.5 pb-1 at 172 GeV. The e+e- -> nunu+photon cross section
is measured. The data are in good agreement with predictions based on the
Standard Model, and are used to set upper limits on the cross sections for
anomalous photon production. These limits are compared to two different SUSY
models and used to set limits on the neutralino mass. A limit of 71 GeV/c^2 at
95% C.L. is set on the mass of the lightest neutralino ($\tau_{\chi_{1}^{0}}
\leq $ 3 ns) for the gauge-mediated supersymmetry breaking and LNZ models.
