LCGT Bandwidth Study 2011 (new design with 22cm mirrors)

1st meeting: 2011 9/9 2pm-4pm slides
2nd meeting: 2011 9/22 10am-12pm slides1,slides2.
Final report is here. (Summary letter is here)

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.

Influence on the detection of high frequency gravitational waves

Minutes of the 1st meeting

2nd meeting reference

Minutes of the 2nd meeting

LCGT/subgroup/ifo/BW2 (last edited 2011-11-01 12:18:29 by KentaroSomiya)