  We investigated the magnetic field dependence of the critical current density
(Jc) in Ba0.6K0.4Fe2As2 with various configurations of columnar defects (CDs)
introduced by 2.6 GeV U or 320 MeV Au irradiations. Splayed CDs are introduced
by crossing CDs at a specific angle with respect to the c-axis, while tilted
CDs are introduced by irradiating the sample from the direction tilted from the
!-axis. We also prepared samples with asymmetric splayed CDs, which bridge the
splayed CDs and the tilted CDs, by starting from the tilted CDs and adding CDs
along the symmetric direction with respect to the !-axis. In all cases,
non-monotonic magnetic field dependence of Jc, which we call anomalous peak
effect, is observed at some fraction of the matching field when the magnetic
field is applied along the specific direction depending on the configuration of
CDs. We propose a model that explains the behavior of the anomalous peak effect
in samples with different configuration of CDs.
