Goal of this procedure: Enter oven mode and reach desired oven profile

Instructions: To keep track of changes to the procedure - copy this page, date it, and add execution notes in red. Remember to save changes.

Table of Contents:


Link to elog summary:

enter here

Procedure

Update 4/8/2024 for simplified 

Checkout and setup - Perform these steps several hours before opening the oven valves


Procedure Execution notes
1Record goal density and helium buffer pressure
  1.  Buffer gas = 5 Torr
  2. Oven current goal of ~8.2 A
  3. Oven temp: TC4/TC5 = ~850 degC

                         TC1/TC7 = ~445/485 degC

  1. Plasma density = 4.3e16 cm-3

2

Set 10 Torr gauge set points to plus and minus 1 Torr of desired pressure

    • Note: the hysteresis value is where the trip occurs, the lower value is where the fault will clear
 

5.5 set Sp,  6.05 Hyst SP

4.4 set Sp,  3.96 Hyst SP

3Set the 1000 Torr gauge setpoint to 30 Torrdone
4

If using DPS, confirm it is operating nominally and record the starting IP pressure (VGCC 3259)

Performing pump/purges before running oven:

 - swapped bottles at 19:10, opened fill valve to drain line

 - Set MFC to 50, with PB turbo on and Be window out to purge line for 10 minutes

 - Stopped PB turbo, static fill to 5 Torr for 5 minutes

 - Set MFC to zero to repump out the line. Open PB valve and Be window

 - Refilled to 5 Torr

4

Confirm helium gas bottle is connected to fill line #1, regulator set to 5-10 psig.

Record gas type, starting bottle pressure, and regulator pressure

 UHP He, 2620 psi, 12 psi
5Confirm that the fill line #2 is closed, and that the IOTA controller in rack FKG20-22 is turned off.Closed and off.
6

Zero the 10 and 1000 Torr gauges

Done
7

Fill IP with He to goal IP pressure using:
How to perform a static fill with DPS

Note - the US2/3/4 gauges will trip off shortly after starting the static fill. You will need to restart the gauges (turn cathode HV On), then reset the valve interlocks, reopen the beamline valves, then continue with the static fill. This will happen once every time you pass the threshold of ~1e-3 Torr on US1.

Done


Procedure for oven turn on


Procedure Execution notes
1

Allow gas to flow for a minimum of 30 minutes.

Stop the flow from the mass flow controller

Done - Fill MFC setpoint = 405
2Ensure that gauges US1, US2, US3 and DS1 CC are bypassed.Done
3Confirm the 10 and 1000 Torr setpoints are set appropriately for the desired oven pressureDone
4Confirm the Beryllium window valve VV3208 is closed - close it if not!Done
5

Set up strip-tool of pressure in the plasma oven:

    • VGCM:LI20:M3201:PMONRAW
    • VGCM:LI20:M3203:PMONRAW
  • Saved as DPS_Pressures.stp

Set up striptool of oven thermocouples plus the thermocouples on the bypass line, cooling water jackets, base-plate and air.

  • Saved as Li_oven_startup.stp
Done
6Head out the FKG20 racksDone
7

Set EPS EXPERT Mode to be “ON” by turning the interlock key in the EPS box in FKG20-27 in the gallery.

    • Note: EXPERT mode is “OFF” if the LED light is OFF and EXPERT mode is “ON” if the red light is ON)
Done
8Unlock oven gate valves: Use the key to switch the valve controller labeled VV3183 VV3187 in rack FKG20-22 to "CAMAC" mode DOne
9

Lock the Be window valve to be inserted: Use the same key to  switch the valve controller labeled VV3208 to "LOCAL ONLY" and remove the key.

Note: the EPICS controls for this valve is also password protected so this will be very well configuration controlled.

Done
10

Open oven gate valves 3183 and 3187. (there might be a small amount of helium between the valves).

If the interlock is faulted then perform a valve interlock reset.

Done
11Turn on the oven heater power supply. Open the "Genesys Expert..." panel and select "PS On" to ONDOne
12

Restart the gas flow from the MFC and fill back to the goal pressure.

Note - the beamline valve interlock will likely trip again. If it does, restart the gauges and continue as described above.

Done
13

When you are at the goal pressure - Hit EPS Reset to clear the low pressure fault

Done
14

Set EPS EXPERT Mode to be “OFF” by turning the interlock key in the EPS box in Rack 20-27 in the gallery. (Note: EXPERT mode is “OFF” if the LED light is OFF and EXPERT mode is “ON” if the red light is ON) . 

You are now done at the racks.

Done
15Perform another EPS reset (this is needed to enable the heater)Done
16

Raise heater power slowly (~ 100 Watts per hour) while monitoring the oven pressure and temperature until desired operating conditions and are reached.

This can done manually by entering the voltage setpoint on the E300 panel,


Or - use the automated tool:

screen -S ovenScreen

python $TOOLS/pydm/display/user-facet/tools/ovenStartUp.py [power]

where [power] == target power

To detach the screen:    crtl-a then crtl-d

To reattach the screen:  screen -d -r ovenScreen


Progress is logged in ovenStartUp.log


During the oven heat up:

  • Record I, V, P and time.
  • Monitor temperature of bypass. Do not exceed 100 C on viewports. If 100 C is reached, shut down oven following shut down procedure.
      • (I don’t think this ought to be a concern since it has never gone above 50 degrees and if it does, it may just mean the TC is loose and striking the oven).





Script started at 20:30 with target power of 575 W

  • 5.25 hours to complete script (1:45am)

http://physics-elog.slac.stanford.edu/facetelog/show.jsp?dir=/2024/21/25.05&pos=2024-05-25T23:57:52




Notes from June 2023:

  • 10:44 - 29.5V, 3.4A = 100 Watts,    TC4 = 29.7C

  • 11:45 - 41.7V, 4.8 A = 200 W,        TC4 = 173C

  • 12:45 - 51.3V, 5.9A = 300W,          TC4 = 360C

  • 13:49 - 59.6V, 6.7A = 400 W,         TC4 = 540C

  • 14:43 - 67V, 7.5A = 500 W,           TC4 = 669C

  • 15:45 - 70.4V, 7.8A = 550 Watts,   TC4 = 780C

  • 18:00 - 72.0V, 8.0 A = 575 Watts - TC4 = 832C

17

Fine tune the heater power to reach the desired oven profile. This plot shows the desired heater current vs. pressure:

  • At pressures less than 3 Torr, stay below ~450C on TC 1 and 7.

Note: Reducing the helium gas pressure in a hot oven could cause loss of lithium! Reduce the heater power to achieve the desired oven temperature then slowly reduce the helium pressure. Slowly raising the buffer gas pressure will not harm the oven.

Final oven startup output completed:

http://physics-elog.slac.stanford.edu/facetelog/show.jsp?dir=/2024/21/26.05&pos=2024-05-26T01:44:45


Procedure for oven shut down

9 hours turning down by hand- 11 hours until valves can be closed


Procedure Execution notes
1

Turn off heater supply slowly to reduce thermal stress to the oven tube and wick.

Do this either by hand, or using the automated tool (~ 100 Watts per hour) 

screen -S ovenScreen

python $TOOLS/pydm/display/user-facet/tools/ovenShutdown.py

To detach the screen:    crtl-a then crtl-d

To reattach the screen:  screen -d -r ovenScreen

Script started at ~11pm.

Heaters off by 5am

Should be cold enough to close the oven valves around 9am

2

After the heater power is turned down to 0, wait until oven thermocouples indicate the oven is near room temperature (less than 50°C). Lithium is liquid at 180°C. 

Takes about 11 hours to reduce to 50C

 oven <50C at 11am
3Write down the buffer pressure for the record in the facet elog4.9Torr

4

Close oven gate valves 3183 and 3187. Turn the key to “CLOSE VALVE” in the PLC valve controller in rack FKG20-22 and remove the key. This will disable the valves from opening.

Set the Be window valve 3208 back to CAMAC.

 Done
5Drain all helium gas and open valves to restore pumping. If using DPS then follow:  How to perform a static fill with DPSDone
6Open the Be window valve, remove bypasses, and reset gas types on the gauges to nitrogen.Done


Emergency shut down procedure

If possible the oven should be cooled slowly using the above procedure to reduce thermal stresses on the oven. But in an emergency situation the oven may be put into a safe-mode to prevent loss of lithium using the following procedure. Note that depending on the situation, some of these steps are automatically taken by the EPS.


Procedure Execution notes
1

Close oven gate valves 3183 and 3187.

If there is an EPS fault then this happens automatically.


2

Turn off the oven heater power.

If there is an EPS fault then this happens automatically.

 
3Secure the helium gas source – either drain the IP or ensure DPS is operating in the nominal static fill state: How to perform a static fill with DPS

4

Log the details of the fault and shutdown: type of fault, reason if known, IP pressure, oven temp, and any other relevant information. 
5Turn the key to “CLOSE VALVE” in the PLC valve controller in rack FKG20-22 and remove the key. This will disable the oven gate valves from opening.
6Do not attempt to restart the oven until you investigate, find, and fix the source of the failure.

Figures:

Useful material

E300 Google Drive folder

How to perform a static fill with DPS

TDK-Lamdba GEN100-15 oven heater power supply manual


Li oven sketch with TC locations

Li density profiles

From: Summary of FACET II lithium oven measurements - June 3, 2021

More profiles available in doc (3 Torr, 4 Torr, 6 Torr, 8 Torr

From Ken 4/8/2024:

  • At pressures less than 3 Torr, stay below ~450C on TC 1 and 7.


Temperatures from heat up (8 Torr)and shut down (from 5 Torr)

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