All-particle Cosmic Ray Energy Spectrum with IceTop

We report on a measurement of all-particle energy spectrum of cosmic rays with the IceTop air shower array. IceTop is the surface component of the IceCube Neutrino Observatory at the geographical South Pole. The data were taken during the eleven months, from June, 2010 to April 2011. During that period, IceTop consisted of 73 operational surface stations and formed a nearly symmetrical hexagon. This analysis is based only on the surface detector IceTop, and does not yet incorporate the capability to measure air showers in coincidence with the measurement of the high energy muon bundle in the deep IceCube detector. We present preliminary results for air showers in the energy range 300 TeV to 1 EeV