The Italian Istituto Nazionale di Fisica Nucleare (INFN) and the ICARUS program have originally developed the technology of the LAr-TPC. Exposed in the underground Hall B of the Gran Sasso National Laboratory in Assergi, at 730 km to the neutrino beam from CERN, this large-scale neutrino experiment has been performed with remarkable detection efficiency and it has now successfully completed a three years physics continuous program. It has been a complete success, featuring a smooth operation,

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... gh live time, and high reliability. A total of about 3000 CNGS neutrino events have been collected and are being actively analyzed. In the next two years ICARUS will be considerably improved at CERN with an extensive R&D program. The external dewars of the present T600 detector (760 tons of ultra high purity LAr) will be extensively overhauled and complemented with a similar ¼ scale T150 detector. The R&D improvements are performed in a close collaboration with the LBNE experiment to which the six above INFN Institutions are now participating members. As a main new novelty, a SC magnetic field of about 1 Tesla will be introduced inside the LAr volumes, in analogy to the performance of the traditional bubble chambers. During 2016 it is proposed to move the whole experiment to FNAL where short base line neutrino beams are available, nicely complementing the already approved MicroBooNe LAr-TPC experiment which will start operation in 2014. The presence of ICARUS at FNAL is an important addition to MicroBooNE since, in the absence of "anomalies", the signals of several detectors at different distances from the beam should be a precise copy of each other for all experimental signatures. Because of its reduced mass, the anti-neutrino signal in MicroBooNE is too weak for a sensitive comparison. A definitive clarification of the LSND anomaly therefore requires also the exploration of the anti-neutrino signal provided by a much larger T600 mass. The presence of a magnetic field is required in order to separate the anti-neutrino signal in the simultaneous presence of the neutrino, induced background with the help of a dual magnetized baseline arrangement and the T150 at a much shorter distance. We propose to locate the T600 detector along the Booster Neutrino Beam line (BNB) at an approximate distance of about 700 m; the T150 detector will be located at about 150 ± 50 m from the target. The T600 will also receive in addition a large number (>10 4 /year) of ν e events from the off-axis kaon-neutrino NUMI beam peaked around about 1 GeV in order to adequately prepare for the LBNE long baseline experiment. The ICARUS improved program will be operated as an additional element of the wide short baseline neutrino FNAL physics program. Intended primarily in the framework of the preparatory work for the LBNE collaboration, the ICARUS team is also interested in extending the participation to other short baseline neutrino activities collaborating with the already existing FNAL groups.