2009/03/26

participants:

EVO: A. Freise, F. Terenzi, M. Pichot, F. Bondu

EGO: M. Mantovani, A. Vicere, G. Losurdo, M. Punturo

* Several questions in A. Vicere's talk:

- Model for multi payload suspension?

          M. Mantovani: yes, we need to understand how to control these suspensions

- Multi-mirror cavities: effective model (total length) or really several mirrors?

          M. Mantovani: real poly mirror suspension: better, it allows to understand mode displacement

* Highlights by A. Vicere:

      -siesta can output mechanical ABCD matrices

      -Some workforce may be available when VSR2 starts.

      -Siesta probably not appropriate tool for exploratory studies (several NDRC configurations)

      -Implement new payload: 3-4 months if full time

      -Implement Signal recycling cavity: less clear

Discussion

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1. Siesta or Finesse?

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A. Freise: E2E can save the state space, and has parallelization

A. Vicere: Saving state space available, may be not tested. Parallelization would require a computing scientist. A gain of 10 might be possible.

A. Freise: We need both time domain and frequency domain simulations. Pool of real users is small.

F. Bondu: Time domain simulation: accurate mechanics and control; non linear effects

              Frequency domain: all linear questions

A. Vicere: Cross checks possible with two models

A. Freise: Time domain software useful for students

Conclusion: We need to develop and use both.

2. Simulation for alignment

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M. Mantovani: need simple model to start with, in the static situation

A. Freise: I thought about radiation pressure in Finesse, in the framework of T. Corbitt, calculating both sidebands simultaneously.

Problem is to code optics in C. Would take 2 months for a trained engineer, 6 months including training and debugging.

I wrote a proposal; if funded, it would start autum 2010. I propose help if Virgo provides a person to spend several months (full time or integrated time) on this in the next 12 months.

A. Vicere: for siesta, the path to implement mechanics is clear. For optics, may take 1 year?

Conclusion: F. Bondu identifies a 6 month task in WBS, task attribution TBD by VSC.

Some work may start during VSR2.