  The ultralow detection threshold, ultralow intrinsic background, and
excellent energy resolution of p-type point-contact germanium detector are
important for rare-event searches, in particular for the detection of direct
dark matter interactions, coherent elastic neutrino-nucleus scattering, and
neutrinoless double beta decay. Anomalous bulk events with an extremely fast
rise time are observed in the CDEX-1B detector. We report a method of
extracting fast bulk events from bulk events using a pulse shape simulation and
reconstructed source experiment signature. Calibration data and the
distribution of X-rays generated by intrinsic radioactivity verified that the
fast bulk experienced a single hit near the passivation layer. The performance
of this germanium detector indicates that it is capable of single-hit bulk
spatial resolution and thus provides a background removal technique.
