A carbon black reactor with axial hydrocarbon feed and having an axial zone with triangular cross-section, a wider vortex section for generation of a combustion gas vortex, a reaction section and having essentially tubular shape is useful for the production of high tint and high structure carbon black. In a process for the production of carbon black, hydrocarbon feed is axially introduced into the reactor and contacted with a vortex of hot combustion gases.