Let us assume that a particularly pervert judge (or a subversive one seeking to make a public case) condemns a convicted criminal to slavery, according to the 13th amendment that seems to allow for such a possibility:
13th Amendment of US Constitution
Section 1. Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction.
Setting aside the highly hypothetical details of what that slavery would actually entail, but assuming it is distinct from classical imprisonment, is there anything that could prevent the judge from doing so? And how would one appeal against this decision?
My (overly simplistic) reasoning as a person without background in law is that this article being in the constitution, it would be hard to over-turn it, even on the basis of the US adherence to the Convention to Suppress the Slave Trade and Slavery?