NAOJ GW Elog Logbook 3.2
I calculated how the coating brownian thermal noise will change in the case KAGRA mirrors will employ crystalline coatings. The mechanical loss I used is 4.5e-6 at cryogenic temperature (from G.Cole, et.al, "Tenfold reduction of brownian noise in high-reflectivity optical coatings", Nature photonics, 2013)
I took the LCGT design sensitivity curve contributions from KAGRA website. I replaced the brownian coating thermal noise with the one for crystalline coatings, and I replaced the quantum noise with the one calculated by Eleonora with the frequency dependent squeezing.
I calculate the horizon of BBH and BNS for the sensitivity curves:
- Amorfous coating ; no squeezing BBH = 3.28 GPc, BNS = 360 MPc;
- Amorfous coating ; squeezing BBH = 4.42 GPc, BNS = 509 MPc;
- Crystalline coating ; no squeezing BBH = 3.46 GPc, BNS = 378 MPc;
- Crystalline coating ; squeezing BBH = 4.90 GPc, BNS = 566 MPc;
d_H = (G^5/6 * M^1/3 * mu^1/2) / (c^3/2 * pi^2/3 * rho) * sqrt( 5/6 * int_f1^f2 f^(-7/3) / S(f) df)
M is the sum of the 2 masses, mu is the reduced mass, rho is the SNR, f1 and f2 are the frequency range for the event signal, S(f) is the noise spectrum (square of the equivalent strain)
I used f1=10Hz; f2_BBH=73Hz; f2_BNS=1571Hz
M_BH = 30M_sun (M=60 M_sun)
M_NS = 1.4M_sun (M=2.4 M_sun)
rho = 8