Active nuclear spin maser oscillation with double cell E. Hikota, M. Chikamori, Y. Ichikawa, Y. Ohtomo, Y. Sakamoto, T. Suzuki, C.P. Bidinosti, T. Inoue, T. Furukawa, A. Yoshimi et al. (11 more) EPJ Web of Conferences, 66 (2014) 05005 Published online: 20 March 2014 DOI: 10.1051/epjconf/20146605005