Eur. Phys. J. A (2016) 52: 23
https://doi.org/10.1140/epja/i2016-16023-4

Regular Article - Experimental Physics

Test of the CLAS12 RICH large-scale prototype in the direct proximity focusing configuration

¹ Argonne National Laboratory, Physics Division, 9700 S. Cass Ave, 60439, Argonne, IL, USA
² Duquesne University, Department of Physics, 317 Fisher Hall, 15282, Pittsburgh, PA, USA
³ INFN, Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044, Frascati, Italy
⁴ INFN, Sezione di Ferrara, Polo Scientifico e Tecnologico. Edificio C. Via Saragat 1, I-44122, Ferrara, Italy
⁵ INFN, Sezione Genova, Via Dodecaneso 33, 16146, Genova, Italy
⁶ INFN, Sezione di Roma, Gruppo Sanità and Istituto Superiore di Sanità, I-00161, Rome, Italy
⁷ INFN, Sezione di Bari, Via E. Orabona n.4, I-70124, Bari, Italy
⁸ Jefferson Laboratory, Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, 23606, Newport News, VA, USA
⁹ Università degli Studi di Ferrara, Via Saragat 1, I-44122, Ferrara, Italy
¹⁰ University of Glasgow, School of Physics and Astronomy, Kelvin Building, University Avenue, Glasgow G12 8QQ, Scotland, UK
¹¹ Universidad Tecnica Federico Santa Maria, Valparaiso, Chile

^* e-mail: marco.mirazita@lnf.infn.it

Received: 10 September 2015
Accepted: 21 December 2015
Published online: 11 February 2016

Abstract

A large-area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3GeV/c up to 8GeV/c for the CLAS12 experiment at the upgraded 12GeV continuous electron beam accelerator facility of Jefferson Laboratory. The adopted solution foresees a novel hybrid optics design based on aerogel radiator, composite mirrors and highly packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large-angle tracks). We report here the results of the tests of a large-scale prototype of the RICH detector performed with the hadron beam of the CERN T9 experimental hall for the direct detection configuration. The tests demonstrated that the proposed design provides the required pion-to-kaon rejection factor of 1 : 500 in the whole momentum range.