THE OBSERVATION OF PRIMARY COSMIC-RAY BY JAPAN-RUSSIA COORPORATIVE BALLOON EXPERIMENT

点击翻译按钮获取中文摘要

This experiment has been carried out for the purpose of making clear so called "knee" in the cosmic-ray energy spectrum which is a rapid change in an inclination of spectrum. Long duration balloon flights (about 150 hours) from Kamchatka to Volga River were carried out 11 times from 1996 to 1999, and 10 flights were succeeded in the observation of cosmic-ray.Both side of Japanese and Russian researchers visited each other countries to have a check and discussion about analyzed data, discussion about energy determination and calculation of detection efficiency, by use of this Grant-in-Aid and others. The main results obtained by this research is as follows.1. Energy spectrum obtained by our experiment has a good agreement with the extrapolation from the lower energy spectrum.2. Our result in proton spectrum is consistent to the result by JACEE (Japan and USA co-operative experiment) and SOKOL (Russian experiment), and flux in helium spectrum has a twice difference compared to the result … More form above two experiments.3. Flux and slope inclination of spectrum for heavy particle has also rather large differences compared to above experiments.These results were reported in 1999 international cosmic-ray conference held in Utah, USA and 2001 international cosmic-ray conference held in Hamburg, Germany. The flux obtained by most of air shower experiments had been giving higher value compared with our data up to 2001 conference, however, many air shower groups reported the results of flux similar to our result in 2001 conference. Moreover the result in our energy region by direct observation is only our report, and our result was highly appreciated by rapporteur.The paper about results of the data to 1996 was published in the 22nd ISTS Proceedings (Vol. 2 p1831-1836) and Astor Particle Physics (No. 16 2001, p13-46). The data of 1999 experiment is under analysis. As 1999 experiment corresponds to four times flight, and it will take more one or two years to obtain the final results. Less