Gamma ray detection with CHIMERA at LNS: results and perspectives

Abstract

We describe the use of the 4 CHIMERA charged particle detector as a large efficiency -ray detector. The CsI(Tl) stage of the CHIMERA telescope is used to detect and identify-rays. The high detection efficiency and the sufficient energy resolution guaranteed by CsI(Tl) allows us to use the detector for the study of rare decays. Two examples are reported: the low probability gamma decay (<10%) of the Pygmy resonance of a radioactive nucleus as the 68Ni; the measurement of the gamma decay probability of excited levels of 12C as the Hoyle state at 7.65 (~10-4 ) MeV and the 3- level at 9.64 MeV (~10-7 ), both important for the Carbon production in stars. Future experiments made possible at INFN-LNS by the availability of the new fragment separator FRAISE are also outlined.