2023/06/05 - Dry Run Li Oven Turn on Procedure

Goal of this procedure: Dry run of Li oven with DPS - enter oven mode and reach 4.4e16 cm^-3 density

Previous oven starts for reference:

Partial turn on Apr 2022: https://docs.google.com/document/d/1TPUW0z_i-7Vx2m_zEdZUqQBcJCBV5NeGSVI7sqzpukY/edit#heading=h.32m2ntkkx5x0

Full oven turn on, March 2022: https://docs.google.com/document/d/1GbIDUUrkBUZddmMIRYI8oGO_QmrOtwqQLqWcXPvgOL8/edit#heading=h.32m2ntkkx5x0

Table of Contents:

E-log entries:

June 5 - http://physics-elog.slac.stanford.edu/facetelog/show.jsp?dir=/2023/23/05.06&pos=2023-06-05T20:30:15

June 6 - http://physics-elog.slac.stanford.edu/facetelog/show.jsp?dir=/2023/23/06.06&pos=2023-06-06T23:44:05

June 7 - http://physics-elog.slac.stanford.edu/facetelog/show.jsp?dir=/2023/23/07.06&pos=2023-06-07T09:90:55

Procedure

Checkout and setup

	Procedure	Execution notes
1	Record goal density and helium buffer pressure	5 Torr He buffer. TC4 at 840 degC → 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	Set to 4 Torr lower, 6 Torr upper limit - upper SP = 5.5 → Hyst SP = 6 (trips at 6, clears at 5.5) - lower SP = 4.4 → Hyst SP = 4 (trips at 4, clears at 4.4)
3	Set the 1000 Torr gauge setpoint to 20 Torr	Set to 20 Torr
4	Confirm helium gas bottle is connected to fill line #1, regulator set to 5-10 psig.	1700 psi in bottle at start → Enough gas for 10 days at 165 psi/day usage. Test will be <3 days
5	Confirm that the fill line #2 is closed, and that the IOTA controller in rack FKG20-24 is turned off.	Confirmed
6	If using DPS, confirm it is operating nominally.	All pumps nominal. US3 CC gauge is dead.

Procedure for oven turn on

	Procedure	Execution notes
1	Verify vacuum conditions approximately 1e-6 Torr or better - Record pressure	1.4e-09 at DS2 with DS-Be window open. Opened VV 3172
2	Zero the 10 and 1000 Torr gauges	ok
	Purge fill line by running a small amount of He through the fill valve and then stopping and pumping out the IP - *Record final pressure*	Bottle on - 1700 psi, Fill # 1 open, then flow valve opened up to 0.1 flow for few minutes. Flow valve closed, then Fill #1 closed DS1 pressure at 1e-8 after 5 minutes (Be window open)
3	Set EPS EXPERT Mode to be “ON” 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)	ok
4	Unlock oven gate valves (switch to CAMAC mode)	ok
5	Open oven gate valves 3183 and 3187. (there might be a small amount of helium between the valves). Continue pump down to 1e-6 Torr - *Record pressure*	DS1 pressure spiked to mTorr for an instant. <1e-9 after 30seconds.
6	Close angle valve VV3201 isolating the plasma beamline from the plasma turbo	ok. plasma turbo will not be used
7	Check Beryllium window valve VV3208 is closed- close if not!	Closed. PB FV closed, PB turbo stopped.
8	Set up strip-tool of pressure in the plasma oven: VGCM:LI20:M3201:PMONRAW VGCM:LI20:M3203:PMONRAW	ok
9	Fill IP with He to goal IP pressure. If using DPS then follow: How to perform a static fill with DPS	Set all gauges to Helium Bypassed US1, US2, US3, and DS1 CC gauges ~0.79 SCFH to reach 5 Torr
10	Hit EPS Reset to clear the low pressure fault	ok
11	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) .	ok
12	While at the racks, Turn valve control for the beryllium window valve to local only and remove key. Note: the EPICS controls for this valve are also password protected so this will be very well configuration controlled.	Done
13	Back at the computer, perform an EPS reset (this is needed to enable the heater)	ok
14	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	ok
15	Raise heater power (Upstream Heater PS1) slowly (~ 100 Watts per hour) while monitoring the oven pressure and temperature until desired operating conditions and are reached at approximately 550 W (table and plot in next column)- we probably need 10% higher than UCLA to match the profile so don’t be scared to push it up a bit to 600 W. Epics control ready to go - 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).	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 16:37 - 71.1V, 7.9A = 560 Watts, TC4 = 820C 17:35 - 71.7V, 8.0 A = 570 Watts - TC4 = 830C 18:00 - 72.0V, 8.0 A = 575 Watts - TC4 = 832C 22:30 - 72.15V, 8.0 A = 577 Watts - TC4 = 836.7C Next day (6/6/2023) 07:40 - 72.5V, 8A = 582.5 Watts TC4 = 837C 08:05 - 72.8V, 8A = 587 Watts TC4 = 837.5 08:45 - 73.0V, 8.1A = 590.5 Watts TC5 = 838.6 10:00 - TC4/5 at 839. Power increases are making the oven longer, but not rising middle TC temp very much Notes: TC6 is giving very bad/noisy readings, TC7 is a little flaky. Need to check connections on next PAMM Cooldown for 4 Torr oven mode - 835C 10:40 - 71.7V, 7.9A = 570 Watts, TC4 = 840C 11:13 - 70.4V, 7.8A = 550 Watts, TC4 = 836 11:43 - 69.8V, 7.7A = 540 Watts, TC4 = 831 12:07 - 69.2V, 7.7A = 530 Watts, TC4 = 828 - reducing pressure to 4 Torr (0.72 SCFH flow) 12:40 - 71V, 7.9A = 559 Watts TC4 = 820C - warming back up for 4 Torr oven mode 13:00 - 71.7V, 7.9A = 570 Watts TC4 = 823C 13:14 - 72V, 8A = 575 Watts TC4 = 824C 14:00 - 72.5V, 8A = 582.5 Watts TC4 = 825C 15:00 - outer TC's are not quite at eq'm, but starting shut down
16	Check that the oven thermocouple readings are nearly the same as those shown on the profile plot. Ambient conditions may vary, so fine tune the pressure and heater power as needed. 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.	5 Torr oven, 580-590W TC - Reading TC1 - 382.7 degC TC2 - 717.0 degC TC3 - 819.9 degC TC4 - 839.4 degC TC5 - 839.9 degC TC6 - 489.4 degC (bad sensor) TC7 - 419.4 degC Bypass - 38.6 degC Water jackets - 29.2 degC 4 Torr oven, 580W TC - Reading - UCLA reference TC1 - 380.4 degC - 405.8 TC2 - 714.6 degC - 783.1 TC3 - 811.7 degC - 831.3 TC4 - 826.6 degC - 834.7 TC5 - 826.3 degC - 834.5 TC6 - 493.6 degC (bad) - 805.2 TC7 - 416.1 degC - 477.9 Bypass - 38.3 degC Water jackets - 29.1 degC

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 (~ 100 Watts per hour) to reduce thermal stress to the oven tube and wick.	15:00 - 67V, 500W, TC4 = 825C 16:00 - 60V, ~400W, 806C 17:00 - 51V, ~300W 18:00 - 41V, ~200W 19:00 - 29V, ~100W 20:00 - heater off
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.	TC4 went below 50C at 2 am
3	Write down the buffer pressure for the record in the facet elog	4 Torr. Closed at 6:40am
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.	Closed in EPICS. Will disable when on site. Closed at 8:30am and locked out Be window valve unlocked
5	Drain all helium gas and open valves to restore pumping. If using DPS then follow: How to perform a static fill with DPS	IP drained. Nominal vacuum regained

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.
3	Secure 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.
5	Turn 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.
6	Do not attempt to restart the oven until you investigate, find, and fix the source of the failure.