Confirmation of the current status
The first task of this working group is to establish a consensus between the members about the currently proposed ISC scheme. We will confirm what has been done so far in what degree of detail. Then decide what should be done next.
Parameters
(Classical-noise parameters are here) Parameter LCGT BRSE(2004)1 LCGT BRSE(2007)2 LCGT BRSE(2009) LCGT DRSE(2009) units Wave length 1064 1064 1064 1064 nm Initial Laser Power 300 150 150 150 W Injecting Laser Power into IFO 100 75(carrier) 75 75 W Modulation depth Not defined Not defined RF freq 1 15.025(AM) 9.98125(AM) MHz RF freq 2 49.5825(PM) 59.8875(PM) MHz MC1 length 9.755 9.755 m MC2 length 199.78 180.463? m MC1 FSR 15.525 15.525 MHz MC2 FSR 0.75125 0.831771? MHz MC1 Finesse 1720 1720 MHz MC2 Finesse 1000 1000 MHz EM Reflectivity 0.99995 0.99995 0.99997 0.99997 FM Reflectivity 0.995 0.996 0.992 0.992 PRM Reflectivity 0.76 0.80 0.77 0.77 SRM Reflectivity 0.68 0.77 0.88 0.88 BS Reflectivity 0.5? 0.5? 0.5 0.5 EM Transmittance 2e-5 2e-5 3e-5 3e-5 FM Transmittance 0.00497 0.00399 0.00398 0.00398 (w/o absorption) PRM Transmittance 0.23997 0.19999 0.19998 0.19998 (w/o absorption) SRM Transmittance 0.31997 0.22999 0.11998 0.11998 (w/o absorption) BS Transmittance 0.49997? 0.49999? EM Loss 3e-5 1e-5(3e-5?) 2e-5 2e-5 FM Loss 3e-5 1e-5(3e-5?) 2e-5 2e-5 (w/o absorption) PRM Loss 3e-5 1e-5(3e-5?) 2e-5 2e-5 (2% total loss in PRC) SRM Loss 3e-5 1e-5(3e-5?) 2e-5 2e-5 (2% total loss in SRC) BS Loss 3e-5 1e-5(3e-5?) Arm cavity length 3000 3000 3000 3000 m PR cavity length 14.9899? 45? m PRM-BS length Not defined Not defined m BS-FM X length Not defined Not defined m BS-FM Y length Not defined Not defined m Asymmetry length 1.4990? 7.5? m SR cavity length 17.9878? 45? m SRM-BS length Not determined Not determined m SRC detuning phase pi/2 pi/2 pi/2 degree Arm cavity FSR 0.05 0.05 MHz PRC cavity FSR 19.3166 6.7 MHz Arm cavity Finesse 1250 1548 Arm power gain 796 987 Arm power(single) 0.398 0.3859 MW PR gain 10 10.63 11 11 PRC power on BS 1000 797.14 825 825 W SR gain 10 14.68 ? N/A Arm cavity cut-off frequency 16.14 31.8 31.8 Hz PR cavity cut-off frequency 1.209e6 Hz CARM cut-off frequency 1.189 2.3 2.3 Hz Signal band 236.9 Hz MICH contrast 0.995 0.995 Other loss in PRC Not defined 1e-3 0.02/11 0.02/11 EM mass 50.9 30 30 30 kg FM mass 50.9 30 30 30 kg PRM mass Not defined Not defined kg SRM mass Not defined Not defined kg BS mass Not defined Not defined kg EM ROC 4500 4500 4500 4500 m FM ROC Infinity Infinity Infinity Infinity m FM AR ROC 12 ?? Infinity Infinity m PRM ROC 0.81 ?? m SRM ROC Not defined Not defined m BS ROC Infinity Infinity m EM AR Reflectivity Not defined 1e-3 FM AR Reflectivity Not defined 1e-3 PRM AR Reflectivity Not defined 1e-3 SRM AR Reflectivity Not defined 1e-3 BS AR Reflectivity Not defined 1e-3 EM AR Loss Not defined Not defined FM AR Loss Not defined Not defined PRM AR Loss Not defined Not defined SRM AR Loss Not defined Not defined BS AR Loss Not defined Not defined EM absorption loss (bulk) 20 20 ppm/cm FM absorption loss (bulk) 20 20 20 20 ppm/cm EM absorption loss (coat) ppm FM absorption loss (coat) <1 <1 ppm PRM absorption loss 5 5 ppm/cm SRM absorption loss 5 5 ppm/cm BS absorption loss 5 5 ppm/cm EM thickness 18 15 15 15 cm FM thickness 18 15 15 15 cm PRM thickness Not defined Not defined cm SRM thickness Not defined Not defined cm BS thickness Not defined Not defined cm EM bulk Loss 1000 1000 ppm FM bulk Loss 1000 1000 ppm PRM bulk Loss 1000 1000 ppm SRM bulk Loss 1000 1000 ppm BS bulk Loss 1000 1000 ppm OMC input/output mirror reflectivity 0.8 0.8 OMC end mirror reflectivity 0.99995 0.99995 OMC length 0.07 0.07 m OMC MC FSR 4282 4282 MHz OMC Finesse 14 14 MHz Quantum efficiency Not defined Not defined 0.9 0.9 Frequency Stabilization band width 10000 10000 Hz CARM control band width Not defined 0.1 Hz DARM control band width Not defined 1000 Hz PRC control band width Not defined 1000 Hz MICH control band width Not defined 10 Hz SRC control band width Not defined 1000 Hz
To do list to define parameters for 2009
Reference
Length Sensing Scheme Review by Somiya (Japanese) lcgtrse.pdf
Length Sensing Scheme Review for advLIGO by Somiya AdvLIGO-LSCv4.pdf
I tried to log in but I'm not sure if I am in, so in case, this is Fumiko 
Here I put some kat files I used for calculating LCGT signal matrix. LCGT.kat has all the parameters that are used. Note that it was written more than a year ago, and they are not updated. I will list these parameters when I can here, outside the kat file but for now I just attach some files. Also note that they are the same as what Andreas Freise has, because I made these when he needed to collect some LCGT parameters and some kat files and so on. Maybe Koji remembers about him contacting us about a year ago, do you??
Here I have three kat files with three m. files and what do they do?
- : With contourplot.m, it is used to make contourplots of error signals.
- : With demphase.m it is used to create a text file "phase.txt"
- which shows demodulation phase that procuces maximum signals.
- :With signalmatrix.m, it is used to create two text files, "matrix_raw.txt" and "matrix_norm.txt" which show signal matrix with raw values and normalized valies respectively.
ok, now I try to attach files hope it works like this...hm.
2004 data referred to LCGT design document 1.0. (1)
2007 data referred to LCGT design document 2.0 and TAC presentation at 2005/8/23 (2)