What is the appropriate punishment for refusing to provide evidence in a civil contempt case?

The difference between a sentence for civil contempt and a sentence for criminal contempt, however, is not a difference in the language of the contempt citations, but in the intended effects of the orders, punishment (criminal contempt) or coercion (civil contempt). See Gompers v. Bucks Stove & Range Co., 221 U.S. 418, 441-43, 31 S.Ct. 492, 55 L.Ed. 797 (1911). To achieve the purpose of a criminal contempt citation, punishment for acts of disobedience, the proper sanction is imprisonment for a definite period of time. On the other hand, the appropriate civil contempt remedy for refusal to provide testimony is imprisonment until the testimony is supplied or the trial ends.