Johan Alme, Rene Barthel, Aart van Bochove, Vyacheslav Borshchov, Robert Bosley, Anthony van den Brink, Edwin Broeils, Henner Büsching, Viljar Nilsen Eikeland, Ola Slettevoll Grøttvik, Younghoon Han, Naomi van der Kolk, J. H. Kim, Taejun Kim, Youngjoon Kwon, Magnus Mager, Qasim Waheed Malik, Else Okkinga, T. Y. Park, Thomas Peitzmann, Fabian Pliquett, Maksym Protsenko, Felix Reidt, Sebastiaan van Rijk, Ketil Røed, Tim Sebastian Rogoschinski, Dieter Röhrich, Marcel J. Rossewij, G. B. Ruis, Emilie Haugland Solheim, Ihor Tymchuk, Kjetil Ullaland, Nigel Keith Watson, Hiroki Yokoyama
- The first evaluation of an ultra-high granularity digital electromagnetic calorimeter prototype using 1.0-5.8 GeV/c electrons is presented. The 25×106 pixel detector consists of 24 layers of ALPIDE CMOS MAPS sensors, with a pitch of around 30~μm, and has a depth of almost 20 radiation lengths of tungsten absorber. Ultra-thin cables allow for a very compact design. The properties that are critical for physics studies are measured: electromagnetic shower response, energy resolution and linearity. The stochastic energy resolution is comparable with the state-of-the art resolution for a Si-W calorimeter, with data described well by a simulation model using GEANT and Allpix2. The performance achieved makes this technology a good candidate for use in the ALICE FoCal upgrade, and in general demonstrates the strong potential for future applications in high-energy physics.
