Electron cloud instability in high intensity proton rings

An $e^{-}p$ instability has been observed in some proton rings. The instability, which causes beam loss, limits the performance of the ring. The instability may be serious for 3 and 50 GeV proton storage rings in the Japan Proton Accelerator Research Complex (J-PARC). We study the $e^{-}p$ instability in several high intensity proton storage rings operated in the world. This work informs J-PARC of the necessity to cure the instability, for example, by applying a TiN coating on the chamber surface.