A comprehensive theory is developped to describe the expansion of a plasma into a vacuum with a two-temperature electron distribution function. The characteristics of the rarefaction shock which occurs in the plasma when the hot- to the cold-electron temperature ratio is larger than 9. 9 are investigated with a semi-infinite plasma. https://www.kaliboat.com/product-category/food-servicecommercial-kitchen-equipmentfood-preparation-equipmentother-commercial-food-prep-industrialrestaurant-business-6/