|
Size: 282
Comment:
|
Size: 939
Comment:
|
| Deletions are marked like this. | Additions are marked like this. |
| Line 1: | Line 1: |
| The reference cavity is locked using a 21.5Mhz signal from a rack mounted board (FSS REF - Crystal Frequency Reference [http://www.ligo.caltech.edu/docs/D/D980353-C.pdf]) | The reference cavity was locked using a 21.5 MHz signal from a rack mounted board (FSS REF - Crystal Frequency Reference http://www.ligo.caltech.edu/docs/D/D980353-C.pdf). That turned out to have many problems and we removed it completely from the system circa 2008 with a fixed 21.5 MHz OCXO from Wenzel and an RF Amplifier (see [http://nodus.ligo.caltech.edu:8080/40m/986 elog]). |
| Line 3: | Line 3: |
| See also [[Frequency Stabilization Servo]]. | We got the design parameters for the reference cavity from [http://www.ligo.caltech.edu/docs/D/D980670-00.pdf D980670] |
| Line 5: | Line 5: |
| Some FEA of the LIGO/40m reference cavity using COMSOL: [[/FEA]] |
|| Spacer Material || Fused Silica (Corning?) || || Mirror Material || Fused Silica || || Mirror T_HR || 300 +/- 30 ppm || || Mirror R_AR || < 500 ppm || || Mirror RoC || 500 mm || || Cavity Length || 8" (203.2 mm) || || Cavity Finesse || || || Cavity g-factor || || || Cavity FSR || 737.7 MHz || || Cavity pole || || Some FEA of the LIGO/40m reference cavity using COMSOL: [[/FEA]] ---- See also [[Frequency Stabilization Servo]]. |
The reference cavity was locked using a 21.5 MHz signal from a rack mounted board (FSS REF - Crystal Frequency Reference http://www.ligo.caltech.edu/docs/D/D980353-C.pdf). That turned out to have many problems and we removed it completely from the system circa 2008 with a fixed 21.5 MHz OCXO from Wenzel and an RF Amplifier (see [http://nodus.ligo.caltech.edu:8080/40m/986 elog]).
We got the design parameters for the reference cavity from [http://www.ligo.caltech.edu/docs/D/D980670-00.pdf D980670]
Spacer Material |
Fused Silica (Corning?) |
Mirror Material |
Fused Silica |
Mirror T_HR |
300 +/- 30 ppm |
Mirror R_AR |
< 500 ppm |
Mirror RoC |
500 mm |
Cavity Length |
8" (203.2 mm) |
Cavity Finesse |
|
Cavity g-factor |
|
Cavity FSR |
737.7 MHz |
Cavity pole |
|
Some FEA of the LIGO/40m reference cavity using COMSOL: /FEA
See also Frequency Stabilization Servo.