Fall 2001
Early September
The power recycling cavity (PRC) locks for a couple of seconds while the
Michelson passes through fringes. This is possible because we have an
electronic automatic gain control in the PRC control loop.
Early October
The PR mirror is misaligned, so the PRC cannot be used and we have
only feedback to the intermediate mass of the triple pendulum suspension.
The Michelson locks on a mid-fringe operation point (not the dark
fringe).
October 15 – 18
Performance of the first GEO testrun! We want to test the data
acquisition system and the long term behaviour of the whole system. So
we obtain data sets for the detector characterization that were taken
under well defined conditions.
Early November
The power-recycled Michelson locks for a few seconds on a dark
fringe. The feedback was given to the electrostatic drive allowing to
exert a force between the lowest mass of the reaction pendulum and the
mirror itself.
Mid-December
The power-recycled Michelson locks for 30 minutes on a dark
fringe with the feedback given to the electrostatic drive and the
magnetic actuator at the intermediate pendulum stage.
December 28, 21:00 UTC
Start of the test run of GEO 600, in coincidence with LIGO (Hanford and Livingston), in order to test the performance and stability of the system as well as the acquisition and exchange of data
