Abstract
The Nupix-R1 is a prototype Monolithic Active Pixel Sensor designed for the Electron-ion collider in China. It consists of 128 rows × 128 columns of square pixels with a pitch of 26.3 µm. Since it is implemented in a 130 nm commercial triple-well process, the in-pixel circuit contains only NMOS transistors. The Nupix-R1 can simultaneously measure the energy, arrival time and position of particle hits. In addition, it can also record only the hit positions with a novel zero-compression scheme to increase the readout speed and reduce the data volume. This paper will discuss the design of the Nupix-R1 sensor.