This morning we countinued the activity of thursday (Acoustic injections in CEB hall) performing more injections:
- we did white and band limited injections with one speaker inside the DET lab SAS --> we se the bumps at 50Hz and 160Hz can be easily excited
- Marco Vardaro disengaged the squeezer and closed the SQZ shutter, and we repeated similar injection --> the bumps at 50Hz and 160Hz are NO MORE excited
- we moved the same speaker next to the SR south flange (see picture) and together with the other speaker that was left on CEB north terrace we produced a beating at 180Hz with 50s modulation (LIGO technique) --> we create a location depended modulation pattern, the data of CT accelerometer and Hrec have to be correated
- we performed some band limited and 180Hz line injection with the shaker attached at DET cryotrap --> seems the shaker cannot excite the 180Hz bump, the 180Hz line yes, data to be analyzed
- performed some tapping (quick and blind) in some locations of SR and cryotrap (see log file) --> data to be analyzed
Attached is the log file with gps details
Analysis and figures about each item above will follow.