I found that the BS/PRM OL SUM channels were reading close to 0. So I went to the optical table, and found that there was no beam from the HeNe. I tried power-cycling the controller, there was no effect. From the trend data, it looks like there was a slow decay over ~400000 seconds (~ 5 days) and then an abrupt shutoff. This is not ideal, because we would have liked to use the Oplevs as a DC alignment reference during the vent I plan to use the AS camera to recover some sort of good Michelson alignment, and then if we want to, we can switch out the HeNe.
*How can I export PDF from NDscope? |