If I have let’s say an ionized gas, composed purely of singly charged positive ions; what would be the permitivity of the material? Is it infinite, as is the case with a perfect conductor, or am I missing out on something here?

Let’s say I place this ionized gas in a STATIC electric field, then the ions would rearrange in such a way to cancel the field, and hence the permitivity constant is essentially infinite - is my reasoning correct?

Now consider the case with an OSCILLATING electric field - how would the dielectric permitivity vary then for the ionized gas?

Just to be clear, I am NOT referring to a quasi-neutral plasma: I am referring to let’s say a cloud of O+ ions, with the ejected electrons completely removed from the cloud.