Chen, D (reprint author), Yokohama Natl Univ, Fac Engn, Yokohama, Kanagawa 2408501, Japan.
We have already reported the first result on the all-particle spectrum around the knee region based on data from 2000 November to 2001 October observed by the Tibet-III air-shower array. In this paper, we present an updated result using data set collected in the period from 2000 November through 2004 October in a wide range over 3 decades between 10(14) and 10(17) eV, in which the position of the knee is clearly seen at around 4 PeV. The spectral index is -2.68 +/- 0.02(stat.) below I PeV, while it is -3.12 +/- 0.01(stat.) above 4 PeV in the case of QGSJET+HD model, and various systematic errors should be carefully done in the very near future. (c) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.