Charge resolution of the ISS-CREAM SCD measured with a heavy-ion beam
G. Hong, Y. Amare, T. Anderson, D. Angelaszek, N. Anthony, K. Cheryian, G.H. Choi, M. Copley, S. Coutu, L. Derome, L. Eraud, L. Hagenau, J.H. Han, H.G. Huh, Y.S. Hwang, H.J. Hyun, S. Im, H.B. Jeon, J.A. Jeon, S. Jeong, S.C. Kang, H.J. Kim, K.C. Kim, M.H. Kim, H.Y. Lee, J. Lee, M.H. Lee, J.F. Liang, J.T. Link, L. Lu, L. Lutz, A. Menchaca-Rocha, T. Mernik, J.W. Mitchell, S.I. Mognet, S. Morton, M. Nester, S. Nutter, O. Ofoha, H. Park, I.H. Park, J.M. Park, N. Picot-Clemente, R. Quinn, E.S. Seo, J.R. Smith, P. Walpole, R.P. Weinmann, J. Wu, Y.S. Yoon
The Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) is scheduled to be launched and installed on the ISS in August 2017, and will carry out a measurement of the energy and composition of energetic cosmic rays in space. The Silicon Charge Detector (SCD) will identify the charge of through-going cosmic rays. It consists of four layers, each with 2688 silicon pixels and associated electronics. The ISS-CREAM payload was delivered to the launch site, Kennedy Space Center, in August 2015 after the successful completion of integration and space environment tests. A heavy-ion beam, required to verify the capability of precision charge measurement of the SCD, became available at the European Organization for Nuclear Research (CERN) in November 2016. A prototype instrument using the same types of silicon pixel sensors and electronics installed in the SCD was placed in a heavy-ion beam composed of secondary ions ranging from helium to zinc. We present the charge resolution for each ion as a function of the number of layers used for charge measurement so that the improvement in charge resolution is clearly demonstrated as the number of layers for charge measurement increases.