Advanced VIRGO optical configuration WG1 teleconference 
15.09.06 

Topic: Preparing the R+D recommendation document by October

Participants:

A. Freise, P. Hello, G. Losurdo, B Mours, M. Punturo, F. Cavalier, 
J. Smith, J. Marque, M. Mantovani, M. Varvella, E. Campagna
(Excused. E. Tournefier)

Proposed changes to the document format:

Concerning WG1, the document states:
'optical configuration, interferometer sensing and control, auxiliary optics'
but 'auxiliary optics should be replace by more specific term thermal compensation.

From the list of topics listed so far we agrees that 'detection systems' 
should be organised better by WG2. However, we should add 'Effects of high 
light power' (or something to that effects and 'alternative beam geometries'.

Comments and actions with respect to the subtopics:

1. Signal Recycling

   - M. Varvella has become an expert in E2E modeling software during
     her stay in Caltech but the visit shows that the knowledge transfer
     from a distant prototype is limited. Conclusion: we need to have
     our own experimental effort! (See general discussion at the end)

2. LSC
 
   - LSC and ASC are closely related but in terms of optical configuration
     can also be perused independently    
   - LSC should be independent from 'signal recycling' as the use of the
     latter has not been decided upon.
   
3. ASC

4. Lock acquisition 

   - A dedicated WG meeting should be called to discuss whether auxiliary 
     systems be used to perform a 'pre-lock-acquisition' to sub-lambda accuracy.

5. Thermal Compensation

   - Ask Napoli+NIKEF for input

6. Effects of high laser power

7. Alternative beam geometries

   - Ask Annecy and Nice for input

General discussions during the telecon:

- prototype: there is a very strong feeling that we need to build a prototype
  interferometer to be able to get Advanced VIRGO commissioned on a realistic
  time scale. The most effective way forward would be to start constructing
  a prototype immediately and to conduct simplified table-top experiments
  in parallel. The prototype can then be used to test the best results
  from the table-top as soon it becomes operational. This would not only
  allow to improve the subsystem designs but also to train scientists
  with the control of the new complex interferometer. In summary, this route
  can reduce the commissioning time of Advanced VIRGO to an acceptable level.

Tasks related to the document:

- compile a list of 'useful' R+D projects, stating clearly what questions
  the respective project can answer
- extract a list of most urgent R+D projects from the above list