Got several hours of PEM follow-up injections last night. This is follow-up on findings in the first round https://dcc.ligo.org/DocDB/0144/G1701613/002/GenevaTalkSm.pdf. Work on identifying the high magnetic coupling in the output arm, the scattering in the input and output arms identified during PEM injections, whether there is significant scattering from the P-cal TX and RX ports and the source the high vibration coupling in the 600 Hz region of the BS. Partial progress, little time.