Balloon observation of electrons and gamma rays with CALET prototype

We carried out a balloon observation of cosmic rays using a prototype of the CALET at the Sanriku Balloon Center of the Japan Aerospace Exploration Agency. The prototype detector consists of 1024 scintillating fibers for track imaging and 24 BGO scintillator logs for total absorption of showers. The observation was carried at an altiude between 35 and 37 km for about 3.5 hours. We measured electrons and-rays in the energy region between 1 to 100 GeV, and 20 MeV to 1 GeV, respectively. In addition to verification of the prototype system, we have obtained the electron flux which is useful to investigate solar modulation. Now we are planning a series of balloon experiments with larger-scale detectors and longer-duration flights, which includes one-month observation by a super-pressure balloon.