Attachment 'memo110323.txt'
Download 1 I have a few comments, i think it easier to make them on writing.
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3 As I said, the parameter table maintained by Gianni is the interface between the simulation and the mechanics.
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5 For the IP and standard filters the mechanics is more or less locked.
6 We should use the simulation only to check that there are no big mistakes and show stoppers.
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8 For the payload it is different;
9 we should not check the parameters of the simulation against those parameters,
10 but we should use the simulation to impose the parameters to the table and the mechanics.
11 The aim is to choose whatever share of masses you think best.
12 Then Gianni and I will try to make a mechanics that satisfy the parameters imposed by the simulation, and come back to the simulation if we cannot do it in practice.
13 An urgent aim is to decide as soon as possible if we need to consider a larger payload.
14 I consider the payload locked at 300 kg, unless there is a serious reason.
15 The share of masses inside the payload is at present completely free.
16 Of course as we proceed with the design, more and more parameters will become locked.
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18 I gather from what Ettore said that we should do a heavier Intermediate Recoil Mass and a lighter Intermediate Mass.
19 Ettore, do you want to suggest a better share of masses for the next iteration of Gianni's table? Maybe 30%IRM - 70% IM ?
20 In the same kind of ideas, we did not discuss if my idea of making a composite mass with the 10 kg mirrors into s 30 or 40 kg ring is reasonable.
21 Ettore can you give your comments about the control aspects?
22 Everybody, do you have comments about mounting in a ring vs. suspending directly the 10 kg mirror. We give away thermal noise for sure, do we give away anything else if we do it?
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24 It is probably a good exercise for Takanori to continuously check the coherence between the simulation and the mechanics.
25 This will be hard at the beginning, but get easier later. He should continuously ask questions to me, Ettore, and others to make sure that he understands everything well. After a while he will be well comfortable with both simulation and mechanics.
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27 Other comments:
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29 I heard today that the coordinate system in Virgo and LCGT are different.
30 LCGT is at the beginning, I wonder if it wouldn't be better to switch to the Virgo coordinate system, to avoid confusion.
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32 As Ettore has mentioned, the Dutch are active in simulation, and assist us in testing.
33 Should we invite them in our wednesday meetings?
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35 ettore mentioned a problem involving torque response of the suspension wires and Poisson ratio.
36 i did not understand it. Could it be a problem more related to electrical wiring, rather than suspension wire?
37 This is probably something that Ettore and i should discuss more on the phone.
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39 Riccardo
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