PX284 - B4 - ensembles

• a collection of copies of the system representing all different possible microstates

the microcanonical ensemble

• it describes an isolated system with fixed energy

the canonical ensemble

• it describes a system which can exchange energy with a large reservoir
• it fixes the temperature of the system

the grand canonical ensemble

• it describes a system which can exchange energy and particles with a very large reservoir
• it fixes the temperature of the system, as well as the chemical potential $(\mu )$

image: Dr R. K. Pandey