Bravo MBE Bring Up
This page describes how to bring up Bravo immediately following the removal of the last glovebag from the system.
Keep this page updated as procedures change
Day 1
Reconnect water lines on the machine
Uncap any capped lines (9/16" and 1/2" wrenches)
Connect the lines that run between cell nipples
Connect the water manifold lines to the machine, but not to the manifold
If needed, change the water filter near the ceiling first. See Water Filters procedure page. There shouldn't be a lot of water, but use a dirty bin to catch any water. The filter housing will have water in it. Cell cooling lines have normal water in them.
Plug quick disconnect lines into the water manifold on the ceiling
Return first, then supply
Monitor if water is actually flowing
Check the Swagelok pieces on the machine for leaks
Keep an eye on the Echo water manifold pressure
Adjust the flow on the water manifold's flow meters
There are Sharpie arrows on each meter indicating the correct flow values
Check:(1) the main return and (2) the deep upward-looking dopant electronic flow meters. Want a green light, not red! The cause for a red light is insufficient flow, e.g. 1. flow meters need to be adjusted. It is also possible for the electronic flow meters to be broken, in which case you need to swap out the meter for a new one (~$300). We also need to check the echo flow interlock light. Also, we might need to pour more water into the chiller.
Use a funnel and the used cell water jugs (distilled water) until there is a nice amount of water visible in the chiller inlet
Remove tape that was used to hold the shutters in place during maintenance
Check the full travel of all the shutters and make any needed adjustments to ensure that the shutters can sufficiently open and close when later connected to pneumatic lines. It is also significantly easier to make any major shutter adjustments with the shutter wheel off.
Attach shutter wheel
This is a two person job. One person to attach the wheel and the other to guide the person
Leave the 4 rods that the shutter wheel to the machine slightly loose. This give the rods a slight amount of play, making it much easier to line up the shutter wheel with the 4 rods
Make sure the shutter wheel is lined up vertically and lined up with two diametrically opposed rods (e.g. top/bottom or side/side) before pushing the wheel onto the rods
Attach shutter rods, but do not completely attach to shutter. Just barely hook the shutter rods to the shutters.
Adjust shutter rod length
One person adjusting rod length and another person watching through a convenient viewport.
Hold the rod next to the nipple on the end of the shutter bellows. Move the rod with the shutter to get a good estimation of how far the shutter is moving and if the rod needs to be adjusted. You might not need to adjust some rods, but others may need significant modification, especially if a cell next to that particular shutter was worked on during the recent maintenance cycle.
The 'closed' position means the shutter is fully closed in the pocket, or at least sufficiently so that it is blocking the crucible and is not running into any side walls
The 'open' position means the shutter is well clear of the cell's crucible as to not block the flux profile
After a rod is adjusted to the correct length, attach the rod to the shutter. Check the travel one final time
For the Si/Be dual dopant (DD) cell, check that the shutter does not block either the Si or Be. You'll need to adjust the DD cell shutter selector, which is at the base of the DD cell (out of vacuum).
Repeat for all source cells
Plug in pneumatic serial cable to the shutter wheel
Wire in the RHEED and deep upward-looking shutters to the pneumatic control box. They should have labels indicating which wires go where.(Red wire connects to higher header stage; White wire connects to lower header stage)
Plug in the pneumatic air supply
Using the shutter control panel or AMBER, actuate each shutter
Make sure that each shutter is moving
Listen for any 'clinking' or 'scratching' noises which can indicate that a shutter is misaligned and needs further adjustment
Check that the shutter speed is correct, i.e. the air supplied to the shutter actuator is correct
To adjust the newer style pneumatic valves: the adjustment pin closer to the center of the shutter wheel regulates opening and the pin farther from the center of the shutter wheel regulates closing. To increase/decrease the opening or closing speed, loosen the larger dial (acts as a set screw) and adjust the smaller dial ccw/cw. Make sure you close down the larger dial after adjusting the smaller dial.
Connect source flange water
If needed, change the water filter on the ceiling first. See Water Filters procedure page. There will be lots of water, so use a trash bag to catch it as it pours out. If you get drenched with water, change your suit ASAP, because the SF water is poison water (water and ethylene glycol).
Connect the return line first, then the supply line. When uncapping the return line, there will be some water, so have a bucket to catch it.
Open the return valve on the ceiling until the flow meter light on the electronic flow meter changes from green to red.The water will fill the filter. Then you can gradually open the source valve until the flow meter light on the electronic flow meter changes from red to green again.
The supply valve will not need to be open all the way to cause the flow meter to show a green light. Still increase the supply valve a bit more to build in a comfortable margin (again, doesn't have to be all the way open).
Watch Echo's source flange pressure and electronic flow meter to make sure it does not trip an interlock
After the Bravo water is stable and producing a green light, increase the supply for Echo (recall it was closed down at the start of maintenance because Bravo and Echo share the same line -- disconnecting Bravo diverts unused Bravo water to Echo). The supply doesn't need to be open all the way, but just enough to build in a comfortable margin above its "green light" state.
Disconnect interlock shorts on the back side of the Eurotherm boxes for gallium (and AHS - 8/28/2023) and reconnect the non-shorted interlock cables
Plug in all source cell power cables
Set all the cell temperatures to 10 C in AMBER
Make sure all Eurotherms are in manual before starting
Only plug in Al Base because of Al creep
Connect/pair silver (power) to whiter (thermocouple) and black (power) to black (thermocouople)
Plug the power cable first then thermocouples
After all power cables are plugged in
Set all cells, except As and Sb crackers and sublimators, to 'auto' mode
Warm up all cells (again, except As and Sb) to 150 C. Base temp = Tip - 50 C.
Do this in manual mode, because lower temperatures can cause the cell to be unstable (e.g. power ramps on and off...)
Approximate manual power values:
InBase 8.5% (208 deg. C)
InTip 0% (270)
Alternative option: InBase 0% (180 C) and InTip 6.1% (240 C)
GaBase 2.5% (133)
GaTip 3.5% (165)
AlBase 6.0% (375)
Er 3.4% (187)
BiTip 5.6% (204)
BiBase 0% (179)
SbSub 0% (31.6)
AsSub 0% (24.4)
AsCracker 1.6% (89.4)
SbCracker 1.0% (102)
Substrate 5.7% (195)
DUL Be 2.0% (99)
DUL SiSUSI 8.2% (NA, no thermocouple, should draw 5 Amps)
DUL GaTe 1.4% (96)
DDBe 1.0% (100.1) (cell now on Echo)
DDSi 1.0% (101) (cell now on Echo)
Disconnect interlock shorts on the back side of the Eurotherm boxes for gallium (and AHS - 8/28/2023) and reconnect the non-shorted interlock cables
Plug in all source cell power cables
Set all the cell temperatures to 10 C in AMBER
Make sure all Eurotherms are in manual before starting
Only plug in Al Base because of Al creep
Connect/pair silver (power) to whiter (thermocouple) and black (power) to black (thermocouople)
Plug the power cable first then thermocouples
After all power cables are plugged in
Set all cells, except As and Sb crackers and sublimators, to 'auto' mode
Warm up all cells (again, except As and Sb) to 150 C. Base temp = Tip - 50 C.
Do this in manual mode, because lower temperatures can cause the cell to be unstable (e.g. power ramps on and off...)
Approximate manual power values:
InBase 8.5% (208 deg. C)
InTip 0% (270)
Alternative option: InBase 0% (180 C) and InTip 6.1% (240 C)
GaBase 2.5% (133)
GaTip 3.5% (165)
AlBase 6.0% (375)
Er 3.4% (187)
BiTip 5.6% (204)
BiBase 0% (179)
SbSub 0% (31.6)
AsSub 0% (24.4)
AsCracker 1.6% (89.4)
SbCracker 1.0% (102)
Substrate 5.7% (195)
DUL Be 2.0% (99)
DUL SiSUSI 8.2% (NA, no thermocouple, should draw 5 Amps)
DUL GaTe 1.4% (96)
DDBe 1.0% (100.1) (cell now on Echo)
DDSi 1.0% (101) (cell now on Echo)
Adjust Cell temps to the following values
Be, Si --> 350 C
GaTe --> 100 C
Dual dopant (DD) Be --> 350 C
In, Ga tips --> 200 C
Er --> 200 C
Bi tip --> 200 C
Need to manually adjust Al to 400 C. There are lots power fluctuations because of the unmelted Al ingots. Typically ~6% OP is about correct. Double check that the correct Al cell TC cables are mated to the power cable (i.e. base to base) otherwise risk unintentionally melting Al early
Reset the minimum allowed setpoints in the Eurotherms and in Amber.
Day 2
Overnight the LN2 should have cooled the chamber such that the pressure will have dropped
Reinstall the As and Sb valve motor controllers
Remove any tape that's still on the valve from the glovebag
Slide the motor controller onto the back of the sublimator and attach by using the controller set screws
Always replace the helical coupler set screw at the start of every new campaign -- easy to strip screw head. Screw type is 1/4 inch 4/40 with 3/32 inch hex drive - SDM/SRB
Use a 3/32" Allen wrench to tighten the helical coupler axle collar/ring set screw. This locks down the helical coupler so the motor is fully attached
Install power to the back of the motor box. The power cables are marked
Rehome the valves using the valve controller box
'local' + 'home'
'Manually calibrate?' --> NO!
'Test full travel?' --> NO!
Change back to remote
Set shutters to remote
Warm up the As and Sb sublimators and crackers
See recipe from 2018-10-11
Before starting make sure:
both As and Sb values are rehomed and set to remote
crackers are in auto, sublimators are in manual
Cells temperatures are increased to their low idles, e.g. Ga and In tips to 350 C
Al is in manual and around 400 C or ~6 pct output power
start RGA scan
Load samples for the junk growth and standard quantum wells (Qws) and superlattices (SLs)
After the sublimator and cracker warmup recipe is finished and are stable, you may proceed with the junk growth