Development of multilayer plastic-scintillator-based active proton target

Recently, the effect of tensor interactions in ¹⁶O was investigated via an inclusive (p,d) scattering on ¹⁶O at high-momentum transfer [1]. Possible different contribution of tensor interactions in ⁶He and ⁶Li nuclei has also been predicted [2]. To study and determine the effect of tensor interactions in these nuclei, we plan to perform high-momentum-transfer (p,d) reactions in inverse kinematics using secondary beams of ⁶He and ⁶Li. A thick proton target is necessary because of limitation of beam intensity (<10⁷ cps). However, the degradation of the energy resolution due to the uncertainty in the depth of reaction vertex becomes an important issue. To address this issue, we have developed a multilayer plastic-scintillator-based active proton target, where the reaction position is determined by utilizing the difference in energy loss due to the particles before and after the reaction. We conducted a elastic scattering experiment with a proton beam of 70 MeV at CYRIC,Tohoku University to evaluate the performance of the active target. In this talk, we will introduce the principle and structure of the active target and report the results of the development experiment.

 

[1] H.J. Ong et al., Phys. Lett. B 725, 277 (2013).

[2] W. Horiuchi et al., Phys. Rev. C 76, 024311 (2007).