“Detector activities” after the IB upgrade

1. “Detector activities” after the IB upgrade Michele Punturo

2. What we must do • 0 priority: • commissioning • 1 priority: • Items to be implemented • Acoustic shielding in the laser lab • Improvement of the cleanliness procedure in the towers • New coil drivers • … (MC LC windows?) … • Items to be investigated: • MC end mirror • Better substrate • Heavier payload • BS mirror • Larger mirror • Reduce scattered light • Eddy current dissipation • New electronics • Thermal compensation & Phase camera • New quadrant centering devices (galvanometers) • …

3. Virgo+ Activities • New high power laser • N. Mann • FS monolithic suspension activities • M.Punturo

4. Acoustic Shielding in the LL • Reduce the cross talk between the acoustic channel and the dark fringe • All the racks with fans displaced during the shutdown • A coverage of the laser table and of the external injection bench is under design • Two offers received: • 30 k€ • 16 k€ • A third company contacted • Offer in few days • Implementation: • End of winter, beginning of spring • As soon as an executive design will be available it will be shown in a detector meeting

5. Cleanliness improvement in the tower • Wednesday, past week: • When the NI problem occurred I prepared (16/04/2003) this list of rules: • Keep the mirror clean • Remove the dust particles through an ionized air jet after the integration and tuning procedures • Inject, during the venting only dray air • Warm up the mirror, to reduce the probability of condensation on it • Some of them haven’t been respected • Need to patch the problem now (cleaning intervention) • Need to solve the problem in the future • Control of the moisture • Ionized warm air flux (need of infrastructure upgrade, already indicated in the urgent purchases in the October 2005 Detector Meeting in Naples)

6. Actuation Noise G.Losurdo

7. New coil drivers • New coil drivers have been designed by INFN Pisa + EGO support to solve the actuation noise problem • Two different sections • High power section for lock acquisition • Low noise section for linear regime • The two sections are driven by two independent DACs • Full production of new coil drivers in one year • Prototypes already installed in the end towers (EM contamination) • Simplified solution in the input towers (switch+resistor) • Simplified solution in the BS tower

8. NEW end MC mirror • The losses in the MC are 846 ppm (F.Bondu) instead of 115 ppm • Defects and contamination in the curved MC mirror • This mirror must be replaced

9. Small or large MC mirror? • Two new small substrates have been sent to GS Lumonics (Raffaele, could you confirm?) • The possibility to use a large substrate must be investigated • Better control of the payload • “almost” standard geometry • Herasil substrate available • Movement mechanics complicated • Optics + Mechanics studies must be started now

10. WA NI IB wedge New BS? • Stray light is evident in the BS • With the higher injected power the problem should be enhanced • Larger BS needed • New substrate (wedge) to be realized

11. Virgo design M=0.017 A m2 Stainless Steel RM sRM=1.4×106W-1m-1 Qeddy=1.8×108 Current design M=0.05 A m2 Aluminum RM sRM=3.2×107W-1m-1 Qeddy=9.4×105 Eddy current FUTURE problem Experimental test: (VIR-NOT-PER-1390-27 (1996), VIR-NOT-PER-1390-80 (1997), Rev.Sci.Instr. 69, 2777 (1998))

12. Magnetic Field Now steel support Aluminum RM Macor support coil magnet post mirror

13. With Iron Hat

14. Test in Clean Room

15. Conclusions • In parallel to the commissioning activities many “detector activities” are foreseen (and many more are needed) • Man power is an issue: • Many persons are involved in both commissioning and “detector”