A semi-analytical foreshock model for energetic storm particle events inside 1 AURami Vainio, Arttu Pönni, Markus Battarbee, Hannu E. J. Koskinen, Alexandr Afanasiev and Timo LaitinenJ. Space Weather Space Clim., 4 (2014) A08DOI: https://doi.org/10.1051/swsc/2014005