I modified autolocker for MC in low power mode (/opt/rtcds/caltech/c1/scripts/MC/autolockMCmain40m_low_power) to make it work with the current directory structure.
autolockMCmain40m_low_power currently runs on op340m and it is in crontab.
34 * * * * /opt/rtcds/caltech/c1/scripts/general/scripto_cron /opt/rtcds/caltech/c1/scripts/MC/autolockMCmain40m_low_power >/cvs/cds/caltech/logs/scripts/mclock.cronlog 2>&1
MC intra-cavity power:
Currently, incident beam to the MC measured at PSL table is ~15 mW. Reflected power from MC (C1:IOO-MC_RFPD_DCMON) is 0.94 when MC unlocked, and is 0.088 when locked.
That means, considering MC1/3 power transmission is 2000ppm (calculated finnesse=1570), intra-cavity power in MC is ~7 W.
15 mW * (0.94-0.088)/0.94 / 2000ppm = 7 W
We can increase the power by factor of ~2, if needed.
MC beam spot positions:
I aligned MC to maximize transmission (C1:IOO-MC_TRANS_SUM_ERR), and measured the MC beam spot posisions in atm, low power.
# filename MC1pit MC2pit MC3pit MC1yaw MC2yaw MC3yaw (spot positions in mm)
./dataMCdecenter/MCdecenter201206290135.dat 2.914584 4.240889 2.149244 -7.117336 -1.494540 4.955329 before vent
./dataMCdecenter/MCdecenter201207011253.dat 3.294659 3.416584 2.620511 -6.691800 -3.164084 4.806517 after vent
They look the same within the error of the measurement, except for the spot positions on MC2, which we don't care.
Autolocker should be refined:
To make autolockMCmain40m_low_power, I copied autolockMCmain40m and just changed
- lockthresh from 500 to 100
- use mcdown_low_power instead of mcdown
- use mcup_low_power instead of mcup
The difference between mcdown_low_power and mcdown should be only
- ezcawrite C1:IOO-MC_REFL_GAIN 31 for lowpower, 9 for usual
- ezcawrite C1:IOO-MC_VCO_GAIN 10 for lowpower, -5 for usual
The difference between mcup_low_power and mcup should be only
- ezcawrite C1:IOO-MC_REFL_GAIN 31 for lowpower, 12 for usual
- ezcawrite C1:IOO-MC_VCO_GAIN 31 for lowpower, 25 for usual
Currently, they are not like that. Somebody good at shell scripts should combine them and make it into one code with an option something like usual/low-power.