The MINOS device is one of the detection project of the LENA laboratory group working on the exotic nuclei. MINOS was developed to perform studies of the structure and spectroscopy of very rare exotic nuclei, which were not possible using other technics than MINOS, conceived to increase the luminosity for the reactions induced by radioactive beams of low intensity (few particles/s). MINOS is a thick H2 cryogenic target of H2 (length from 10 to 15 cm) surrounded by a TPC detector, a time projection chamber needed for the trajectory measurements of the particles produced by the reaction on the proton target. From the track reconstruction the reaction vertex can be obtained event by event. It is needed for the Doppler correction used in the gamma measurements operated by the photon spectrometer used for the spectroscopic experiments.
MINOS was conceived by IRFU for the reactions induced by radioactive beams produced by the accelerators at large energies, between 150 and 700 MeV/n: the beams foreseen with the FAIR machine at GSI (400-700 MeV/n) and the ones delivered since 2007 by the RIBF facility at RIKEN (secondary beams energies between 150 and 350 MeV/n).
Preliminary experiments (2012-2013) to prepare the MINOS campaigns in Japan
In the framework of the SUNFLOWER (Spectroscopy of Unstable Nuclei with Fast and sLOW beam Experiments at RIBF) collaboration at Riken, experiments were carried out in 2012 at RIBF with the photon detector DALI2 to measure the reaction cross sections of interest for the future spectroscopic studies via knock-out processes. The goals were to measure the spectroscopy of 102,103,104Sn via knockout reactions, inelastic scattering and Coulomb excitations (RIBF74, spokespersons SPhN, RIKEN).
In October 2013, an in-beam test of the MINOS TPC chamber was done with beams delivered by the HIMAC facility (Chiba, Japan), the validation of the trajectograph was achieved.
Top view of the MINOS detector inside the array of NAI detectors of the DALI2 spectrometer. thr device was implanted in the BigRIPS beamline (F8 area) of the RIBF facility of the RIKEN accelerator[ SEASTAR2 campaign in May2015. photo: IRFU, V.Lapoux]
Experimental campaigns SEASTAR in 2014-2017 at RIBF with MINOS
The group was co-spokesperson of the three SEASTAR campaigns done in May 2014, May 2015 and May 2017, to search for the spectroscopy of the first 2+ states of very rare exotic neutron-rich nuclei produced by the RIBF facility in the BigRIPS line.
Recent results and MINOS publications, highlights on the results of the 2015 campaign:
- data taking 2014/2015, Exploration of the most exotic nuclei using MINOS