We performed acoustic injections in both terminal buildings. Details are in the attached log file.
The purpose is double: 1) check if the coupling has changed after more that one year; 2) produce better coupling function for the IME deliverable "acoustic rooms for racks".
We injected different kind of noise:
- colored noise 8Hz to 2kHz
- colored noise 10-110Hz
- colored noise 200-300Hz (main emission frequency range of racks)
- line at 220 Hz (one of the main emission frequency of racks) and 240 Hz (NEB only)
At WEB we notice a significant coupling in the region 100-300Hz. Figure 1 and 2. The excited structures in hrec are similar to those excited during the tapping campaign, and are likely realeted to the scattered light issue.
Similar injections at NEB did not produce noticeable effects in hrec (Figure 3)
