A new Low Gain Avalanche Diode concept: the double-LGAD

This paper describes the new concept of the double-LGAD. The goal is to increase the charge at the input of the electronics, keeping a time resolution equal or better than a standard (single) LGAD; this has been realized by adding the charges of two coupled LGADs while still using a single front-end electronics. The study here reported has been done starting from single LGAD with a thickness of 25 \textmu{m}, 35 \textmu{m} and 50 \textmu{m}.