The focal surface of the JEM-EUSO instrument Y. Kawasaki1, M. Casolino2, P. Gorodetzky3, A. Santangelo4, M. Ricci5, F. Kajino6, T. Ebisuzaki1, and the JEM-EUSO collaboration* 1Computational Astrophysics Lab., RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan 2INFN and Physics Department of Univresity of Rome "Tor Vergata", Via della Ricerca Scientifica 1, 00133 Rome, Italy 3APC-Paris 7 University, 10 rue A. Domon et L. Duquet, 75013 Paris, France 4Astronomie und Astrophysik, Eberhard-Karls-Universität, Sand 1, 72076 Tübingen, Germany 5INFN, Laboratori Nazionali di Frascati, Via Enrico Fermi 40, I-00044 Frascati, Italy 6Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501, Japan *http://jemeuso.riken.jp/
Received: 15 Nov 2010 – Revised: 17 Jan 2011 – Accepted: 19 Jan 2011 – Published: 03 May 2011
Abstract. The Extreme Universe Space Observatory on JEM/EF (JEM-EUSO) is a space mission to study extremely high-energy cosmic rays.
The JEM-EUSO instrument is a wide-angle refractive telescope in the near-ultraviolet wavelength region
which will be mounted to the International Space Station.
Its goal is to measure time-resolved fluorescence images of extensive air showers in the atmosphere.
In this paper we describe in detail the main features and technological aspects of the focal surface of the instrument.
The JEM-EUSO focal surface is a spherically curved surface, with an area of about 4.5 m2.
The focal surface detector is made of more than 5000 multi-anode photomultipliers (MAPMTs).
Current baseline is Hamamatsu R11265-03-M64.
The approach to the focal surface detector is highly modular.
Photo-Detector-Modules (PDM) are the basic units that drive the mechanical structure and data acquisition.
Each PDM consists of 9 Elementary Cells (ECs).
The EC, which is the basic unit of the MAPMT support structure and of the front-end electronics,
contains 4 units of MAPMTs.
In total, about 1 200 ECs or about 150 PDMs are arranged on the whole of the focal surface of JEM-EUSO.
Citation: Kawasaki, Y., Casolino, M., Gorodetzky, P., Santangelo, A., Ricci, M., Kajino, F., Ebisuzaki, T., and the JEM-EUSO collaboration: The focal surface of the JEM-EUSO instrument, Astrophys. Space Sci. Trans., 7, 167-169, doi:10.5194/astra-7-167-2011, 2011.