LCGT Bandwidth Study 2011 (new design with 22cm mirrors)
Scope of the meeting
It has recently turned out that the largest S-axis Sapphire available right now is not as large as 25cm in diameter but 22cm.
And the measured absorption of a Sapphire substrate is not as low as 20ppm/cm but 50-70ppm/cm.
It should be also noted that the economic situation is not so good that we cannot expect too much on an additional large budget
within the next few years, and also that it takes three years or more to provide 4 Sapphire mirrors, which means we should
make it in mind that the mirrors we are ordering will be the one we use in 2017.
1st meeting reference
The input power refers the level of absorption; if the total absorption is high we can inject only 25W while the default is 75W.
Here the power recycling gain is set 11, i.e. the power on the BS is 275W, 550W, 825W, for 25, 50, 75W, respectively.
Preliminary cryogenic setup with 1.2W heat and point-scattering effect (It seems that we can inject 75W into
the interferometer, allowing the mirror temperature to be 23.5K instead of 20K).
Influence on the detection of high frequency gravitational waves
GWs from supernovae FILE
Minutes of the 1st meeting
2nd meeting reference