1. MSC recent activities Commissioning Cascina 2 Apr 2007

2. EM-MSC-0204072 Recent/present Quite state recovery (duty cycle) Disturbance Re-jection (duty cycle, sensitivity) > xDamp, cleaner coarse signals to improve control accuracy: meas and offline OK, to be fully implemented (1 standalone shift) > saturation at the WE site (gain tuning): OK > Tall towers, GIPC (global IP control): tested under various conditions, in line. Ready further improvement for anti-  seism sensor blending for NI,WI. > Short tower optimization: off-line work to prepare the optimization works OK, some tests done, to be completed (2 shifts, standalone+ITF check) Noise budget (sensitivity) ===>>> Hierarchical control: 1 st step: improvement of NE,WE actual Ma/Mi blending 2 nd step: BS marionette reallocation (today/tomorrow).

3. EM-MSC-0204073 GIPC (Global Inverted Pendulum Control) benefits: wind disturbance rejection, lock acquisition, duty-cycle. Once the ITF is locked, the mirror position, provided by the Global Control, can be used instead of LVDTs, referred to the ground. Features: - automatic engagement (soft!) - anti-wind blending in NE-WE-BS-PR - anti-  seism in NI-WI GC (reconstructed z) LVDT Splitted anti-  seism /anti-  seism

4. EM-MSC-0204074 Example1: NE_GIPC,WE_GIPC only NE “follows” NIWE “follows” WI step9

5. EM-MSC-0204075 Example 2: NE_ GIPC, WE_ GIPC only step9

6. EM-MSC-0204076 Example 3: NE_ GIPC, WE_ GIPC, BS_ GIPC, PR_ GIPC step9

7. EM-MSC-0204077 Example3: NE_GIPC,WE_GIPC only Thanks to GIPC benefit to Automatic Alignment step9 Short suspension (i.e.beam) improvement necessary ?

8. EM-MSC-0204078 Example,environmental: central Bld, GIPC shock absorption

9. EM-MSC-0204079 > synthesis: net improvement of recent activity Much more  seism and similar peak at 130 mHz In this example: - red data (now) show up similar peak at 130 mHz but much larger  seism. In spite of this: => the force reallocated to the marionette is smaller !

10. EM-MSC-02040710 > noise budget: actuation noise & reallocation -Suitable resistors are used to reduce coil-drivers noise (ln/HP to accomplish sensitivity/locking) -a trade-off with DAC noise using emphasis/de-emphasis was found. Still some work:  BS requires marionette reallocation.  WE,NE have a  seism peak that should be reduced by further force reallocation to the marionette. Too large correction directly on the mirror Low frequency component that can be moved upwards (marionette)

11. EM-MSC-02040711 > conclusions Operation: Continuous attention on operation issues related to operation Strategy disturbance rejection: - A large effort was spent on ID sensing optimization and on “soft operation” - Tools to emulate crucial environmental situations have been developed - Marionette reallocation in 4 suspensions - GIPC in-line To be done before (possibly before the MegaRun): -further technical noise reduction (locking reallocation improvs being done) -improvement of short suspension performance (InjB,MC,OutB, possibly)