FELIX output goes off, and the usually-illuminated button “charge modulator†switches off.
Sometimes the heater for the klystron switches off. If you are quick, you can start it back up with no waiting time. Switch the button “GUN RF timing on†off, and enter the FTA. Go to the heater (close to the end of the rack), and look at the relevant klystron.
1. If the light in “Delay switch†is blinking, take a pen, and press the red reset button. Only do this if you are certain the heater hasn't been off completely, otherwise it might break the klystron tube. Return to the control room, and press "Charge Modulator" and “GUN RF timing on†back on. FELIX should now be running. Some small amount of optimization may be needed - refer to File:Optimizing FELIX.docx.
2. If the light is not blinking, or you are have any doubts, switch the heating unit off and on.
To do this, open the modulator system, and press “localâ€. Switch the top line of buttons off (specifically "high voltage", "line", "klystron", "cooling" and "mode"). In the cabinet next door, press the illuminated "error" button to clear it. Back on the modulator system, press "remote". Everything on the top line should now latch on. The cabinet should now look like below.
With this fix, you need to wait about 35 minutes, until the klystron has reheated. We know the klystron is ready when the heater indicator on the klystron module (4th box down from the top) is "ready". At this point, switch "Charge Modulator" on, and reduce the macropulse time to 2 us / repetition rate to 1 Hz. Switch the gun on and slowly ramp up the macropulse duration. If the electrons are reaching the dump and some light is being produced, revert to 10 Hz. Substantial optimization is probably needed - refer to File:Optimizing FELIX.docx.
Sometimes we want to use FELIX in 50 MHz mode. This latch is located upstairs in the FTA, in one of the cabinets towards the end (FF-11). Do not forget to revert the system back to 25 MHz mode, as there is no obvious indicator for which mode is selected. NOTE: The laser system in US3 relies on a 25MHz timing signal from this point...
2
FELIX output is getting worse over time, but nothing is obviously wrong
FELIX light goes off, but all buttons on the main panel are still illuminated. One of the low level phase settings may have gone to 10%. The electron gun HV has dropped from -98 kV to about 0 V.
Fix: Switch the feedback of “low level RF phases†off, and press the “gun rf timing on†button off. Go to the FTA, up the stairs and to the cupboard FF.09.
1. Check the current of the electron gun – it will (if this is indeed the fault) be 0A. Under the label “Crowbarâ€, there are two black buttons. Press both of these simultaneously, and the current should ramp back up.
2. Go back to the control room, and double-check the vacuum valves are still open. Set the pulse timing to 1 µs, and check that the electrons are reaching the dump (i.e. press “gun rf timing onâ€). Slowly increase the timing back to 10 µs, checking that the electrons still reach the dump. If so, you should be able to see some weak IR light. Optimize the settings - refer to File:Optimizing FELIX.docx.
4
Modulator LINE error
The discharge/grounding plungers, or the 'limit switch' might be stuck. See if there is some movement possible; you may need to shut off the compressed air from the wall behind the modulator cabinets. - ➤ Victor 2018-04-19
Perhaps the crowbar has been engaged, push the reset buttons in cabinet FF-09 (top level).Cabinet FF-09: Press both reset buttons.
6
Cavity: no holes in the screens? or no HeNe visible at all?
* Is the pressurized air (perslucht) still available? Check the (upper) pressure gauge in the FTA antehall (above your head, just behind the main technical area security doors).
7
Beam optics: Slingercircuit not working
Push the interlock reset button on the "RCUFF box" in the FTA next to the slingercircuit power supply
8
Cameras: None of the cameras will open in BO Screens
Check to see if the JAI SDK is running on any of the computers, apparently it can block all cameras from opening elsewhere. ➤ Victor 09:04, 7 February 2020 (CET)
9
Attenuator / Powermeter cannot control any ETH484's
* Victor should fix this, but for now you can try this:
The vacuum tubes in the FELICE halls are rather vulnerable to being opened, since one often has to step over them. If this happens, close the tube, and check which vacuum valves have shut / if the pressure has stabilized. To reset the vacuum pumps, go to the pump controllers in the back of the FELICE hall. On e.g. controllers 7P60 & 7P70 (where the pressures are poor), turn the key to 'override' (horizontal) and press 'open'. If the turbo pump successfully turns on, the pressure will start to drop immediately and rapidly. Turn the key back to vertical. (If the valve closes immediately, the pressure was not yet low enough to disable the override.) Go to the FTA, up the stairs and to the front side of cabinet FF-22. Repeat the key-turning/'overide'/'open' combination. Finally, go to the control room and open the necessary valves, if the vacuum has recovered sufficiently.
11
No Modulator Charging
Check for Errors in the HPRF GUI, and interlock systems, check for errors on the Accelerator, Beam optics and RF led pannel.
The modulators tubes need to be heated before startup. Perhaps that has not happend. Check if the east and west modulator cabinets are in remote. If the modulators are heated up a beebing sound can be heared in the control room. It takes 20 min to heat
