(Kiwamu, Paul, Stefan) This morning we found the back-reflection from the PRM, leaking through the Faraday, back on the PSL table. We measured the following powers: - direct beam, sampled by ~30% BS: 339mWatt - return beam, sampled by the same ~30% BS: 37.0uWatt - as reference, we also measured the power on the REFL beam on ISCT1, just after the periscope: 6.94mWatt Faraday isolation ratio: 37.0uW/339mW, minus other losses (IMC visibility, PRM reflectivity)
Some more small information regarding to this measurement:
The "good" alignment in PRM is :