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GEO600 Status Update Harald Lck Hannover, April 2005 Slide 2 Slide 3 S4 Feb 22nd March 23rd Two manned shifts/day (5-21 UTC), 1 expert on duty 8-8UTC Overnight SMS alarms to expert on duty Locking status DAQS (DCUs running, frame making, timing, calibration) Temperatures Vacuum Instrumental duty cycle 97.5% Slide 4 Typical S4 Sensitivity Violin modes N * 50Hz Calibration lines Laser power PR, E highV, EN lowV MC Turbo SR h [1/sqrt(Hz)] Slide 5 S4 Glitchy periods within the first week Slide 6 Slide 7 Glitches occurred mainly during seismically quiet times Slide 8 Curing the glitches (temporarily) (What is a jump? :-) Slide 9 Intermediate Mass of Mounting Unit 3 probably touched coil holder frame Slide 10 Slide 11 After unstickng MU3 by rotating it Slide 12 BLRMS during S4 Slide 13 Strange sine gaussian glitches h [1/sqrt(Hz)] Slide 14 Strange sine gaussian glitches ctnd. Slide 15 Slide 16 Calibration of GEO600 Time-domain calibration method Optimization routine quasi-continuously estimates parameters of optical response Calibration lines give known differential arm- length disturbance These points are fit to a model Update rate is 1Hz Slide 17 Michelson Servo Error Points P Q Slide 18 On-line optical TF measurements actuator optical CAL P and Q Slide 19 Optical&Electronic Gain Slide 20 Calibration Slide 21 Calibrated EP Quadrature Signals h [1/sqrt(Hz)] Slide 22 Combining h P (t) and h Q (t) III Create filters from noise floor estimates h(t) = Pfilter{h P (t)} + Qfilter{h Q (t)} QQ PP PQ Slide 23 Combining h P (t) and h Q (t) results Get the best of h P and h Q plus a little extra! h [1/sqrt(Hz)] Slide 24 Steps after S4 PR fast autoalignment, Unity gain ~4-5Hz Improve seismic long. FF & long.->IM tilt FF Increase PR factor by changing PR mirror 1.35% -> 0.1% Change laser, increase power to ~12W, i.e. ~5W @ MPR Lock interferometer with ~7kW internal power