This morning during the ISYS shift, we installed the speakers (ENV_NOISE_CEB_EEroom ) and the microphone (ENV_LLR_MIC) in the atrium of the laser lab in order to perform acoustic noise injections.

We then injected noise, making some trials to set the desired type and amplitude. In the attached plot we injected colored noise around 2 kHz (with 1 kHz bandwidth) with amplitude 0.005.

We will make further injections during next monday morning shift, while trying to reduce the noise coupled into the ML fiber by changing the input polarization.