A plasma's flow may be isentropically stable or unstable.
Anna Perelomova 2018, 'Magnetoacoustic Heating in Nonisentropic Plasma Caused by Different Kinds of Heating-CoolingFunction', Advances in Mathematical Physicshttp://dx.doi.org/10.1155/2018/8253210. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The expansion proceeds almost isentropically.
Bravina L., Zabrodin E. 2015, 'Effective equation of state of hot and dense matter in nuclear collisions around FAIRenergy', EPJ Web of Conferenceshttp://dx.doi.org/10.1051/epjconf/20149501003. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)