Attachement

1) We discussed what data are available for the simulation. Please see the attached excel file. Probably no explanation will be needed about the table. Only thing I would like to confirm is whether the deadline of blue boxes is consistent with the bKAGRA schedule. I am positive about sapphire optics, but I forgot the deadline of MMTs. Please let me know.

2) Our general approach is that we start simulation with what we have now (some are perfect optics due to lack of surface information), then replace some data as we get real data. For example, as for sapphire test masses, we will use Pathfinder data (200mm dia) first, then replace with real ETMs data when their polishing are completed early next year. When ITMs are done, we will use four real surface data.

3) Bulk homogeneity will be obtained when ETM's polish is complete. This will be a very important information to decide what level of correction on AR of ITM is needed.

4) for 3), it is assumed that we use the same crystal for ITMs as that for ETMs. However, it is still possible that we use a different maker, expecting lower absorption. If that happens, we probably need some extra steps to know homogeneity information of the different crystal. I am investigating what is needed for this now.

5) Unfortunately, due to lack of RS, we cannot get coated figure data except test masses and BS. We will put some artificial degradation on top of polished data.

6) We should check ROC of MCe when MC cavity is locked.

KAGRA/subgroup/ifo/MIF/Minutes20151005/HiroseReport20151005 (last edited 2015-10-06 05:38:59 by YoichiAso)