Measurement of iron cosmic-ray primaries below 10GeV/n by use of the geomagnetic effect with CALET

Ichimura, M.; Kasahara, K.; Adriani, O.; Akaike, Y.; Asano, K.; Asaoka, Y.; Berti, E.; Bigongiari, G.; Binns, W. R.; Bongi, M.; Brogi, P.; Bruno, A.; Cannady, N.; Castellini, G.; Checchia, C.; Cherry, M. L.; Collazuol, G.; De Nolfo, G. A.; Ebisawa, K.; Ficklin, A. W.; Fuke, H.; Gonzi, S.; Guzik, T. G.; Hams, T.; Hibino, K.; Ioka, K.; Ishizaki, W.; Israel, M. H.; Kataoka, J.; Kataoka, R.; Katayose, Y.; Kato, C.; Kawanaka, N.; Kawakubo, Y.; Kobayashi, K.; Kohri, K.; Krawczynski, H. S.; Krizmanic, J. F.; Maestro, P.; Marrocchesi, P. S.; Messineo, A. M.; Mitchell, J. W.; Miyake, S.; Moiseev, A. A.; Mori, M.; Mori, N.; Motz, H. M.; Munakata, K.; Nakahira, S.; Nishimura, J.; Okuno, S.; Ormes, J. F.; Ozawa, S.; Pacini, L.; Papini, P.; Rauch, B. F.; Ricciarini, S. B.; Sakai, K.; Sakamoto, T.; Sasaki, M.; Shimizu, Y.; Shiomi, A.; Spillantini, P.; Stolzi, F.; Sugita, S.; Sulaj, A.; Takita, M.; Tamura, T.; Terasawa, T.; Torii, S.; Tsunesada, Y.; Uchihori, Y.; Vannuccini, E.; Wefel, J. P.; Yamaoka, K.; Yanagita, S.; Yoshida, A.; Yoshida, K.; Zober, W. V.

doi:10.22323/1.444.0057

The CALET Calorimeter on the International Space Station(ISS) has previously measured the flux and spectrum of iron cosmic-ray nuclei above 10 GeV/n. In order to extend the measurement to the region below 10 GeV/n, we carry out an analysis to utilize the geomagnetic effect. Cutoff rigidities of cosmic-ray nuclei are calculated for all directions for each observation point in the ISS orbit. The integral spectrum of observed rigidities is then obtained by counting the number of iron nuclei in each bin of cutoff rigidity. The absolute flux and differential spectrum are then calculated by taking the detection efficiencies into account. Here we present the details of the analysis procedure and the iron spectrum below 10 GeV/n.

Ichimura, M., Kasahara, K., Adriani, O., Akaike, Y., Asano, K., Asaoka, Y., et al. (2024). Measurement of iron cosmic-ray primaries below 10GeV/n by use of the geomagnetic effect with CALET. In Proceedings of Science. Trieste : Sissa Medialab Srl [10.22323/1.444.0057].