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The primary energy of the ultra-high energy cosmic rays(UHECR) are measured with the number of fluorescence photons which are detected with fluorescence detectors(FD) in the Telescope Array experiment(TA). Howevery since there is large uncertinty as 19% in the measurement of the energy scale, the most important theme is improvement of the energy calibration. The electron light source(ELS) is a small electron linear accelerator for new energy calibration. The ELS is located 100 m far from the FD station, and injects electron beam which is accelerated to 40 MeV energy into the sky. We can calibrate the FD energy scale by detection the air shower directly which is generated by the electron beam. The ELS was developed in KEK Japan, and moved to the TA site in March 2009. We started the beam operation in September 2010, in consequence we detected the air shower which was generated by electron beam in the air. The output kinetic energy of the electron beam was 41.1 MeV, we adjusted the output charge from 40 to 140 pC/pulse. We expect that we can improve the uncertinty of the energy scale to about 10% with the ELS, futhermore ELS will be a very useful apparatus for R&D of future UHECR observation. [ABSTRACT FROM AUTHOR]

The energy spectra of secondary charged particles from 2.04 and 2.5 GeV electron-induced reactions were measured using a current time-of-flight technique at the Pohang accelerator Laboratory. A long flight path and the current time of flight method were adopted to measure the pulse height of each event that reached the detectors in a short period. Secondary proton and deuteron energy spectra were obtained at 90 degrees with respect to the electron incident angle. The results were compared with those calculated by the MCNPX-2.5e code. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Measurement of differential fragment production cross sections for proton- and neutron-induced reactions is described. The double-differential fragment production cross-section for 70-MeV protons and the yields for 75 MeV neutrons were obtained with a specially designed Bragg curve spectrometer (BCS). An experiment is also described for proton-induced reactions employing the E-TOF method to obtain complementary and more detailed information than neutron-induced reactions. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]