Towards a new Liquid Argon Imaging Chamber for the MODULAr project

The MODULAr project foresees the exploitation of a new liquid Argon imaging detector, of at least 20 kt fiducial mass, to be operated in a shallow depth location under the Gran Sasso Mountain. It will be devoted to study neutrino oscillations with an optimized off-axis CNGS neutrino beam. Cosmic neutrinos as well as proton decay will also be addressed. The MODULAr detector will vastly inherit from the technology developed for ICARUS-T600. However, such an increase in the volume over the current ICARUS-T600 needs to be carefully considered. It is concluded that a single, huge volume is an inoperable and uneconomical solution for many reasons. A very large mass is best realized with a modular set of many identical, independent units, each of about 5 kt, ``cloning'' the basic technology of the ICARUS-T600. Several of such modular units will be assembled to reach at least 20 kt as initial sensitive volume. The increase of the active volume of about one order of magnitude with respect to the ICARUS-T600 detector requires some specific R&D activity, which will be implemented in a ∼ 360 ton prototype unit (SLICE) of reduced length.