I installed the new board LIGO-D1800304 with an external voltage regulator and breakout box for handling acromag channels. See attached photos. The transimpedance amplifiers required a parallel capacitor in the feedback path for avoiding oscillations. Since these are temperature sensors and we do not care much about high-frequency noise, I added 1 nF capacitors at the COMIT3,9 and 11 positions. This should give us a bandwidth of 10 kHz. The channels are as follow:
| CH No on Board |
EPICS Channel Name |
Temperature Conversion Function (ºC) |
Range (ºC) |
| 1 |
C3:PSL-TEMP_TABLE |
= V/0.810875 + 27.30248869 |
13.860-40.745 |
| 2 |
C3:PSL-TEMP_VACCAN_INLOOP |
= V/1.625 + 33.3115385 |
26.604-40.020 |
| 3 |
C3:PSL-TEMP_VACCAN_OOL |
= V/1.625 + 33.3115385 |
26.604-40.020 |
Vacuum Can Temperature Control
With the new sensors, I have set relay autotune test to happen overnight with relay amplitude of 0.75V and 0.75 offset for 16 hrs. This should tell us optimal PID parameters. Hopefully, these measures will make the can temperature stable enough which I'll try to set around 33 degrees (my guess setpoint to keep good enough cooling rate). Then with Andrew's new script, the cavity temperature control was pretty good and hopefully we'll lower the overall drift of beatnote. |