A powerful machine learning technique to extract proton core, beam, and α-particle parameters from velocity distribution functions in space plasmas

摘要: Context The analysis of the thermal part of velocity distribution functions (VDFs) is fundamentally important for understanding the kinetic physics that governs the evolution and dynamics of space plasmas. However, calculating the proton core, beam, and α-particle parameters for large data sets of VDFs is a time-consuming and computationally demanding process that always requires supervision by a human expert.Aims We developed a machine learning tool that can extract proton core, beam, and α-particle parameters using images (2D grid consisting pixel values) of VDFs.Methods A database of synthetic VDFs was generated, which was used to train a convolutional neural network that infers bulk speed, thermal speed, and density for all three particle populations. We generated a separate test data set of synthetic VDFs that we used to compare and quantify the predictive power of the neural network and a fitting …