Cosmic ray spectrum from 250 TeV to 10 PeV using IceTop
We report here an extension of the measurement of the all-particle cosmic-ray spectrum with IceTop to lower energy. The new measurement gives full coverage of the knee region of the spectrum and reduces the gap in energy between previous IceTop and direct measurements. With a new trigger that select...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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Format: | Journal article |
Language: | English |
Published: |
American Physical Society
2020
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Summary: | We report here an extension of the measurement of the all-particle cosmic-ray
spectrum with IceTop to lower energy. The new measurement gives full coverage
of the knee region of the spectrum and reduces the gap in energy between
previous IceTop and direct measurements. With a new trigger that selects events
in closely spaced detectors in the center of the array, the IceTop energy
threshold is lowered by almost an order of magnitude below its previous
threshold of 2 PeV. In this paper, we explain how the new trigger is
implemented, and we describe the new machine-learning method developed to deal
with events with very few detectors hit. We compare the results with previous
measurements by IceTop and others that overlap at higher energy and with HAWC
and Tibet in the 100 TeV range. |
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