What is the test for a motion to compel a judge to recuse himself?

"The law is clear that [the judge] must determine whether the affidavit is sufficient, if true, to require that he recuse himself. Only if he finds it thus sufficient is he required to have another judge hear the motion." United States v. Olander, 584 F.2d 876, 883 (9th Cir.1978), vacated and remanded on other grounds sub nom., Harrington v. United States, 443 U.S. 914, 99 S.Ct. 3104, 61 L.Ed.2d 878 (1979); United States v. Azhocar, 581 F.2d 735, 738 (9th Cir.1978), cert. denied, 440 U.S. 907, 99 S.Ct. 1213, 59 L.Ed.2d 454 (1979).