KAGRA MIR (Absorption)
DaisukeTatsumi - 18:19, Monday 07 March 2016 (224)
Mechanical chipper replacement

Because the mechanical chopper on absorption measurement bench was broken,

we bought new one (Stanford research instruments SR540).

Today I repalce the controller (motor driver with local oscillator) of the chopper.

Old chopping motor and wheel are unchanged, since we want to keep the setup

as much as possible.

 

After the replacement, I checked all of cable connections.

And then, I found that many cables are unplugged.

 

Tomorrow I will check the absorption measurement system by using reference samples.

Comments related to this report
ManuelMarchio - 19:32, Sunday 13 March 2016 (230)

On friday afternoon Flaminio and me noticed that the chopper frequency is quite unstable, about 5Hz of standard deviation. The old one was not that unstable. We should check it.

DaisukeTatsumi - 12:43, Friday 11 March 2016 (229)

Two days later, I found that the wheel was stopped.

Therefore, I and Manuel replace the new motor with chopper also.