Kenju Mori

Combination of emulsion chamber and air shower array at Mt. Chacaltaya

Data of 34 familes with the accompanying air showers, observed by the combination of emulsion chamber and air shower array at Mt. Chacaltaya, are presented. Comparison with the simulation calculation concludes that a change is necessary in the characteristics of hadron interactions in E0≥1015 eV.

What can we study through families and accompanied air showers

At mountain altitudes, high energy γ -ray bundles ( γ -rays in parallel trajectories and with the same direction of an air shower) can be observed in the central part of air showers. These γ -ray bundles (≥ 1 TeV ) and their associated air showers are observed simultaneously at Mt. Chacaltaya (5200 m ) by our detectors. The γ -ray bundle in the air shower can give information on the primary composition and the characteristics of proton interaction. In this paper, we report on experimental results, simulations calculated for the present experiments, and also problems in simulations.

Simultaneous observation of families and associated air showers at Mt. Chacaltaya

SummaryThe observation of families and air showers is carried out at Mt. Chacaltaya (5200m, 540 g/cm2 atmospheric depth, Bolivia) by operating the emulsion chamber and the air shower array simultaneously. We summarize in this paper the results of the experiment, leaving the description of experimental apparatus, experimental procedure, etc. elsewhere (Kawasumi N.et al., AIP Conf. Proc.,276 (1992) 88;Proc. XXIV ICRC, Rome,1 (1995) 201). The analysis relies on the data of 47 families of ΣEγ≥10 TeV with the accompaniment of air showers.

VHE gamma-rays with energies above 1014 eV observed at Mt.Chacaltaya

Abstract Observation to detect VHE gamma-ray emissions has been carried out at Mt.Chacaltaya with the SYS air shower array since Feb.1986. A significant excess of hadron-less air showers with energies above 1014eV from the direction of Scorpius X-1 has been found during the last fifteen days in May 1986. However, no excess as the continuous emissions could be observed for several X-ray binary objects in the southern hemisphere. Small abundance of hadron-less air showers could be seen from the diffused region of galactic centre.