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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(PM)

9.98125(PM)

MHz

RF freq 2

49.5825(AM)

59.8875(AM)

MHz

1st MC length

9.755

9.755

m

2nd MC length

199.78

180.463?

m

1st MC FSR

15.525

15.525

MHz

2nd MC FSR

0.75125

0.831771?

MHz

1st MC Finesse

1720

1720

MHz

2nd MC Finesse

1000

1000

MHz

EM Reflectivity

0.99995

0.99995

FM Reflectivity

0.995

0.996

PRM Reflectivity

0.76

0.80

SRM Reflectivity

0.68

0.77

BS Reflectivity

0.5?

0.5?

EM Transmissivity

2e-5

2e-5

FM Transmissivity

0.00497

0.00397

PRM Transmissivity

0.23997

0.19997

SRM Transmissivity

0.31997

0.22997

BS Transmissivity

0.49997?

0.49997?

EM Loss

3e-5

1e-5(3e-5?)

FM Loss

3e-5

1e-5(3e-5?)

PRM Loss

3e-5

1e-5(3e-5?)

SRM Loss

3e-5

1e-5(3e-5?)

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

N/A

N/A

N/A

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

PRC power on BS

1000

797.14

W

SR gain

10

14.68

Arm cavity cut-off frequency

16.14

Hz

PR cavity cut-off frequency

1.209e6

Hz

Coupled cavity cut-off frequency

1.189

Hz

Signal band

236.9

Hz

MICH contrast

0.995

0.995

Other loss in PRC

Not defined

1e-3

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

20

20

ppm/cm

FM absorption loss

20

20

ppm/cm

PRM absorption loss

5

5

ppm/cm

SRM absorption loss

5

5

ppm/cm

BS absorption loss

5

5

ppm/cm

EM thickness

15

?

cm

FM thickness

15

?

cm

PRM thickness

Not defined

Not defined

cm

SRM thickness

Not defined

Not defined

cm

BS thickness

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


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?

lcgt.kat / contourplot.m

dp.kat / demphase.m

s.kat / signalmatrix.m

ok, now I try to attach files hope it works like this...hm.


  1. 2004 data was referred to LCGT design document 1.0. (1)

  2. 2007 data was referred to LCGT design document 2.0 and TAC presentation at 2005/8/23 (2)