Fig. 4From: Acceleration mechanism of radiation belt electrons through interaction with multi-subpacket chorus wavesEnergy increase profile of the most successfully accelerated electron under each initial condition. Comprehensive simulations are conducted under various initial conditions: 60 energy levels and 43 equatorial pitch angles. Each condition is applied for 3600 electrons with different gyrophases and initial positions. The energy increase of the most successfully accelerated electron out of the 3600 electrons in each case is visualized in the colormap. The high energy increase range (colored in red) with lower initial energy electrons results from the RTA acceleration, whereas the range over MeV-class initial energy is due to the URA acceleration. The URA high energy range consists of two bands separated by a cavity at the initial pitch angle of around 70°. The upper band and lower band are formed by the different types of URA: overtaken URA and catching up URA, respectively. The cavity is the intermediate condition, where no efficient acceleration occursBack to article page