Attached are the results of this step test.

• The Vacuum Can Temperature PID reached the setpoint almost immediately.
• The out-of-loop sensor has a different offset but shows same 1-degree change as an in-loop sensor.
• In the FSS Slowout Voltages which control the NPRO Laser temperatures, we can see that South Slow PID goes to a steady-state more smoothly and without much oscillations.
• While the North Slow PID shows some oscillations. I'm not sure what can be concluded from this observation.
• Note that the cavity heater PID was switched off during these measurements but the heaters were left on to the values they were at before switching PID off.
• The second attachment is an exponential decay fit of the slow voltage values after the two steps on each day on each path.
• The values of these time constants vary from 3 hrs to 4 hrs depending on the day and path.
• I was unable to convert the slow voltages to cavity temperature reliably. I found some estimates in CTN:2027 but they were not replied to positively. And the absolute value is still unknown, so this conversion would hardly give any new insight.
• However, since temperature change would be some constant number only, it wouldn't affect the time constant estimate done here.

Code and Data