Advances in reconstructing the cosmic-ray energy spectrum with IceTop

The IceTop array at the surface of the IceCube Neutrino Observatory measures
extensive air showers produced by cosmic-ray particles with energies from PeV up to EeV, covering the transition region from galactic to extragalactic sources. This contribution presents significant improvements that will enhance the measurement of the cosmic-ray energy spectrum.
(I) To analyze more than a decade of data with increasing snow overburdens on the detector, an improved method to handle the time-dependent attenuation of the detector signals was developed.
(II) New analysis cuts have been developed to increase the measured event rate while improving the reconstruction quality.
(III) A new reconstruction method that separately fits the electromagnetic and muonic components, while incorporating data from the deep in-ice detector, enables the reconstruction of air showers with cores outside the IceTop array, up to zenith angles of 50°.
These improvements will significantly increase the event statistics and extend the IceTop spectrum towards higher energies.