Performance test of the MAIKo active target.

Abstract A new active target named MAIKo (Mu-PIC based Active target for Inverse Kinematics ∘) has been developed at Kyoto University and Research Center for Nuclear Physics (RCNP), Osaka University. MAIKo is suited for missing-mass spectroscopy of unstable nuclei at forward scattering angles in inverse kinematics. MAIKo consists of a time projection chamber (TPC), which incorporates a micro-pixel chamber (μ -PIC) as the electron multiplication and collection system. In MAIKo, the medium gas also plays the role of a reaction target, thus allowing detection of low-energy recoil particles with high position resolution. The MAIKo TPC was commissioned with He(93%)+iso-C 4 H 10 (7%) and He(93%)+CO 2 (7%) mixture gasses at 430 hPa. The gas gain and the angular resolution of MAIKo were evaluated with an alpha source and a 4He beam at 56 MeV. The TPC was stably operated up to 1000-kcps beam intensity. A tracking algorithm using the Hough transform method has been developed to analyze scattering events. An angular resolution of 1.3°was achieved for scattered 4He particles. [ABSTRACT FROM AUTHOR]