Is there jail time for non payment of alimony?

No. Not exactly. If alimony is owed, it is a matter of court order. That is a judge ordered the defendant to pay alimony for a specific amount of time to the plaintiff. If the defendant fails to pay the alimony, he is in contempt of court. The plaintiff would need to file a notice of noncompliance with the court (as simple as a letter to the ordering judge) and a bench warrant would likely be issued. If the defendant is not subsequently apprehended by law enforcement, the plaintiff may motion the court to enforce the bench warrant, and which time the judge would issue an order for arrest for the defendant. The defendant would then be actively sought by law enforcement, arrested, and would appear before the ordering judge to explain why he had not complied with the court order to pay alimony.