Compression instability occurs when a gas or plasma, either incident or contained, experiences pressure conditions that make it unstable. The pressure gradient is such that the material is compressed beyond its former size until the material reaches a pressure threshold at which it fractures creating a turbulent and chaotic reaction. Compression instability can occur in a wide range of environments but is most commonly seen in stellar atmospheres.
The development of compression instability is dependant upon several factors; the temperature of the gas or plasma, the rate of expansion, and the ratio of the two competing forces, i.e. the pressure and temperature gradients. In general terms, when conditions become favorable for an instablity to occur the gas or plasma undergoes a chaotic and turbulent mixing, outpacing any efforts to contain or control it.
One of the most significant features of compression instability is that it occurs rapidly and without prior warning or indication. What appears to be a normal and stable situation can be quickly and dramatically altered with the onset of compression instability. As a result, compression instability makes it difficult to predict and prepare for its effects.
One way to reduce the risk of compression instability is to ensure that there is a balanced pressure and temperature gradient. If the pressure gradient is too steep, then this can tip the balance in such a way that an instability could occur. It is also important to ensure that the gas or plasma is not being excessively heated or cooled as this too can lead to an instability.
The impact of compression instability can be significant and generally affects the surrounding environment. It can cause significant mechanical loading which can cause structural damage, it can cause uncontrolled increases or decreases in pressure or temperature, and it can also lead to shockwaves and turbulence which can produce shock loading and damage delicate machinery or systems.
Compression instability can be a dangerous and potentially catastrophic event. It is important, then, that all necessary measures are taken to diminish the risks associated with such an incident. By monitoring the temperature and pressure of the environment, taking steps to maintain pressure/temperature balance, and ensuring that any sudden changes are acted upon quickly, the risk of compression instability can be significantly reduced.