Low power output - Trumpf resonator

[10600nm]

Trumpf, CO2, 12kW, just begins to output about a half of power only.
But even this half looks unstable, floating and slowly and steady degraded down to one third in the 15-20 min.

First I had checked power supply (there are 4 RF generators). All amplifier tubes are fine, all readings per generator are same like days before, each one pumping 100%, and reflected power is low. Nothing looks unusual, no warning messages.

Then I had checked mirrors - all 8 of them looks like new, then I changed (for cause) OC, mode is O.K.
No vacuum leak, no arcing, electrodes are O.K, quartz tubes also like new.
Both turbine blowers running O.K, RPM & frequency O.K, no warning messages.
Then I had dismount one by one gas coolers to observe them for water leak inside of resonator and find nothing suspicious.

Then I put gas (CO2, He and N2) bottles from another running machine – no effect.
Then I swap the gas mixer with one from running machine, but power output still the same: starts with only 7kW and drops down to 4kW in 15 min.

Gentleman, obviously I miss something, but what?

Any advise, guess or idea about are highly welcome!

 

[cuttingedgelaser]

Hi, did you change the mixing block or the gas pump? You can hook up a set of gas flow gauges to see if it is slightly off. I have seen a tremendous drop in power from the flow being off.

 

[cuttingedgelaser]

Is the laser having problems or is the reading on the monitor changing? If so the calorimeter may be faulty.