ContentsBakeout from Atmosphere............................................................................................................2

Overview....................................................................................................................................2Pumping down...........................................................................................................................3Removing non-bakeable items..................................................................................................3Setup of Bakeout Oven..............................................................................................................4Baking........................................................................................................................................ 5After Baking............................................................................................................................... 6Appendix....................................................................................................................................8

Bakeout from Vacuum: No Pumpdown.......................................................................................12

Cable Connections....................................................................................................................... 12

Cleaning Instructions................................................................................................................... 12

Flushing Gas Handling System.....................................................................................................12

Heed: Conditioning......................................................................................................................12

Heed: Taking Data........................................................................................................................12

Ion Yields..................................................................................................................................... 12

Miscellaneous Pump Info.............................................................................................................12

Partial Pressure Analyzer.............................................................................................................12

Picture Guide............................................................................................................................... 12

Pulsed Yields................................................................................................................................ 12

Pumpdown: No Bakeout..............................................................................................................12

Sample Prep.................................................................................................................................12

STAIB: Gun Conditioning..............................................................................................................12

STAIB: Gun data...........................................................................................................................12

Vacuum Break..............................................................................................................................12

Vladimir’s Box Key....................................................................................................................... 12

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Bakeout from AtmosphereUSU Materials Physics Group

Version 1.06/1/2007

Version 2.012/10/2016

ContentsOverview........................................................................................................................................2Pumping down...............................................................................................................................3Removing non-bakeable items......................................................................................................3Setup of Bakeout Oven..................................................................................................................4Baking............................................................................................................................................ 5After Baking................................................................................................................................... 6Appendix........................................................................................................................................8

OverviewBakeout is the process of heating materials for a long time to eliminate substances absorbed in samples. The Materials Physics Group bakes-out to ensure that there are no foreign chemicals, water, etc. in the samples when performing additional tests afterward. This procedure allows for bakeout while there is still air in the bakeout oven, as opposed to a vacuum.

The equipment we use is expensive and difficult to replace, as are samples we receive from agencies. Use these items with care. Similarly, the high heat of the bakeout oven can damage many expensive items around the lab. As instructed, remove these items from the vicinity of the bakeout oven. If you are unsure of any step, ask for assistance.

The appendix pictures several pieces of equipment that are unmentioned in the instructions. These are for your general reference around the lab.

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Remember to complete a bakeout log. These sheets are located in the black binder on the shelf by the door labeled “General Operation.” For examples of how to complete these sheets, look at the older examples in the blue binder on the same shelf. Place your completed log in the back of the blue binder.

Before starting, make sure you have one empty garbage can by the photoyield computer and a plastic grocery bag.

Pumping down 1. Open the main chamber valve (See Figure 1). This opens the turbo pump chamber to the main

chamber, the roughing line (See Figure 4), and its single plug (See Figure 5). 2. Turn on the mechanical pump by plugging in the main black power cord on the back of the

pump and the century valve plugs (See Figure 6). 3. Watch the pump until the pressure in the main chamber pumps down to low 10-2’s. To do this,

watch channel A on the convectron gauge on the turbo pump chamber.4. Turn on the turbo pump using the on/off switch on the left side of the main chamber.5. Watch the turbo until the pressure in the main chamber pumps down to mid 10-6’s.6. Open the ion gun and the HEED gun valve (See Figure 15). This will open the gun chambers

to the main chamber valve.

Removing non-bakeable items 1. Clear the west wall table and the right half of the north wall table.2. Unplug and remove these items to one of the two empty tables:

a. The white cable from the power cord on Vladimir’s Ammeter Box (See Figure 8). b. The photoyield setup (See Figure 13). You’ll want two people to do this. There are

three pieces to the main photoyield setup: the mirrors that align and focus the photon ray, the Deuterium Lamp power supply (See Figure 9), and the Sciencetech power supply (See Figure 11).

c. The computer power cable from the computer. Additionally unplug the other two black plugs in the main computer setup.

d. The blue ion gauge and the gray convectron gauge.e. The stepper motor.f. The TV from the camera.g. The camera.h. All cables on the flood gun control box. i. The flood gun’s shelf. j. The computer cable on the pulse switch box coming out of the top left side of the

main chamber.k. The long coax cable connected to the Grid/Collector switch box (See Figure 25) on

the bottom left side of the main chamber.3. Unplug the following cables, and put them in the garbage can by the photoyield computer.

Note: Twist ties connect the cables to make things easier to reconnect.a. The interlock cable on the back of the HEED gun (See Figure 17). The cable screws

off, but don’t take out the two gold screws.b. The deflection control, alignment control, and blanker HEED gun cables (See

Figures 12, 14, 16).c. Both ion guns’ cables. The Sputter gun has five and the Yield gun has four.d. The seven RGS analyzer cables (See Figure 30).e. The single SEM detector cable.f. The six AES/SEM electron gun cables.

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g. The three STAIB gun cables.4. Unplug the following cables, and place the cables in the grocery bag. When complete, place

Vladimir’s Ammeter Box on an open table, and place the grocery bag on top of Vladimir’s Ammeter Box.

a. The pulse switch box coming out of the top right side of the main chamber. b. The triax cable from the box on the back of the Keithley 230 pulsed side (See Figure

18).c. The coax cables coming from “Ch 1” and “Ch 2” on the Oscilloscope generator (See

Figure 22).d. The coax cable coming from “+ TRIG. IN” on the Pulse Generator (See Figure 24).e. The two cables labeled “GRID CH 7” and “STG. CH 6” connected to Vladimir’s

Ammeter Box and the DAQ board.f. The two bottom triax cables from the Grid/Collector switch box on the bottom left

side of the main chamber.g. The two short coax cables on the Grid/Collector switch box from the main chamber.

5. Move the Grid/Collector switch box with the triax cable still connected to it underneath the north wall table by the Keithley 619 (See Figure 20).

6. Set the Keithley 230 by the Keithley 619 underneath the table.7. Remove the Blanker box under the HEED gun (See Figure 21) and put in the garbage can. To

do this:a. Unplug the coax cable going from the side of the Blanker box up to the top of the

HEED gun chamber.b. Twist the legs on the bottom of the Blanker box counterclockwise (when looking

down from above) to raise them off the table.c. Unscrew the setscrews connecting the top of the Blanker box to the bottom of the

HEED gun chamber with the appropriate allen wrench.d. Set the Blanker box and its two connected coax cables in the garbage can.

Setup of the Bakeout Oven1. Sweep off the table thoroughly.2. Collect the frame from underneath the table. Put on the two table pieces around the main

chamber. Assemble the frame by screwing in the remaining pieces. All of the corner and side pieces are interchangeable.

3. Lay down the fireman’s blankets shiny side up on the table. Caution: The bakeout blankets have fiberglass in them. Handle them carefully.

4. Put the hanging heater in place. It screws into the frame on the middle height bars on the bottom and left sides.

5. Distribute the 10 heater stands and heaters around the table. There should be six around the main chamber and four on the rest of table.

6. Run the cords of the 10 standing heaters and the handing heater to the outlets without plugging them in yet.

7. Run three of the jack plugs to the bottom end of the main chamber so that the hanging heater can use one. There are eight 220 jacks on the far-right end of the table and four 220 jacks on the bottom end of the main chamber.

8. Put the blankets on the frame, and button everything but the bottom snaps.9. Check that the bakeout heater master switch is OFF (See Figure 27).

Note: All chamber-related bakeout switches are on the bottom side of the main chamber.10. Plug in the 10 standing heaters and the hanging heater.11. Check again to make sure no non-bakeable items are touching either the ion pump heaters or

the heating tape on the leak valves.

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12. Turn off the water to the cold water shroud using the green knob labeled “C.W.” located on the side of the hood in the southeast corner of the lab.

13. Blow air through the cold water shroud hose to get out any water still inside.a. There are three white knobs that control water/air flow to hoses.

Note: There are four white knobs in all. The last knob goes to the extra hose connection with nothing connected to it. The knobs are open when the white knob is parallel to the hose and closed when the white knob is perpendicular to the hose.

i. The short, lightest green hose connects the air to the other two hoses.ii. The darker green hose (farthest from you) goes to the cold water shroud on

the Batman chamber. iii. The lighter green hose (closest to you) goes to the cold water shroud on the

Robin chamber. b. If the white knob to the light green hose is not closed and water is coming out of

both hoses in the drain, it means the Robin is using the cold water too. Close the white knob to the light green hose.

c. Make sure the white knob to the dark green hose is open.d. Open the white knob connected to the air. e. Turn on the orange knob labeled “air” on the side of the hood.

Note: Don’t turn it on too high. The water will come rushing out and make a mess. Hold the hose directly over the drain. You may want to shield yourself with the other hand.

f. Close the white knob connected to air after the water has finished draining from the hose.

g. Close the white knob to the dark green hose.h. If the Robin was using the water too, reopen the white knob to the light green hose,

and turn the cold water back on. Note: Make sure you don’t turn the cold water on too high. All that is required is a gentle flow.

Baking1. Turn on:

a. Ion pump heater switch (See Figure 28).b. Bakeout heater master switch, but keep the temperature dial at zero.c. Turbo heater switch located on the turbo pump control box.

2. Plug in the leak valve heater tape.3. Turn up the bakeout heater master switch to three.4. Make sure the standing heaters are working.

Caution: They heat up very quickly.5. Snap down the blankets and fasten them with the black clips.6. Monitor the temperature with the thermal couples during bakeout.

a. Get the yellow thermometer with the fork-like plug from the white cabinet on the east wall of the lab.

b. The thermocouple connection (See Figure 26) is above the ion pump heater power switch. Plug in the thermometer and use the black dial to read the temperature at various places on the main chamber (See Figure 31). Record the temperatures in the bakeout log.

c. Monitor the temperatures often to make sure the heaters are heating evenly. See previous bakeout logs for examples of what normal temperatures are. Some of the thermocouples can read consistently lower than the other thermocouples. We want all the thermocouple points to reach 100° C. However, two points may never get that

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high. If any of the readings are lower than they should be, rearrange the heaters to accommodate.

d. Monitor temperature every half hour or hour, and watch the main chamber pressure closely when the temperature inside approaches 100° C. Note: At 100° C, water evaporates off the main chamber walls. At this point, it’s possible for the pressure to rise enough to turn off the turbo pump. If this occurs, turn it back on again as soon as the pressure reaches the 10-2’s again.

7. Bakeout for approximately 3 days.a. Close the turbo pump to the main chamber at night. You can leave the turbo and

mechanical pumps on, but shut the main chamber valve in case of a power outage.b. Close the main chamber valve at night. However, when you close it, watch the

pressure. If the pressure rises beyond a little bit for closing the valve, the ion pump can’t handle the work. If this happens, shut the ion pump off for the night.

8. Turn the ion pump and the cold water shroud on for the rest of the bakeout if the pressure drops below 10-6’s into the 10-7’s at any point while baking-out. Leave the main chamber valve open and pump with both the turbo and ion pumps. See “After Baking,” step 11 and 12 for instructions on turning the cold water shroud back on.

After Baking1. Degas the filaments. The black control box is below the turbo pump control box and above the

pressure reading box.a. Ensure the computer cable coming out of the front of the control box connects to the

one coming out of the back of the desk computer.b. Turn the computer power on.c. Open the program on the computer called “Dycor System 2000.”d. Turn on the filament, which is the yellow light bulb on the menu bar.e. Go to “Control,” “Degas,” “Degas the filament.” The pressure will rise inside the main

chamber, peak, and then drop back down again. f. Turn off “Degas the filament” after the pressure drops down again.g. Close the program and turn off the power for all three ion gauges: the one in bottom of

chamber, the one the right side of chamber, and the one on top of the main chamber’s upper-left corner.

h. For each gauge, press the “degas” button. The pressure readings will rise, peak, and then drop back down again. After it drops again, turn the “degas” button off.

2. Close the roughing line to the turbo pump chamber and the main chamber. 3. Close the ion gun leak valve (See Figure 2) that connects the ion gun to roughing line.4. Close the HEED gun leak valve that connects the HEED gun to the main chamber.5. If the ion pump isn’t on yet and if pressure is low 10-6’s or lower, turn on the ion pump, shut the

main chamber valve, and turn the cold water shroud back on (see step 11 and 12 below). Make sure pressure drops when the ion pump turns on. If not, turn the pump and the water on, but leave the main chamber valve open and let the turbo help for a while.

6. Turn the bakeout heater temperature dial on the master switch down to zero.7. Turn off the following:

a. The bakeout heater master switch. b. The turbo pump heater. The power switch is on its control box.c. The ion pump heater. The power is below the thermocouple dial.

8. Unplug the 10 standing heaters, the hanging heater, and the leak valve heater tape.9. Leave the fireman’s blankets on, but unclip and unsnap the bottom.10. Let everything cool for 12 to 24 hours.11. Watch the pressure as the main chamber cools. If not done previously, turn on the ion pump and

shut the main chamber valve when it reaches low 10-6’s. Make sure pressure drops when the ion

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pump turns on. If not, complete the next step, but leave the main chamber valve open and let the turbo help relieve the main chamber pressure for a while. Try to close the main chamber valve again in an hour or so.

12. Turn the cold water shroud back on when turning the ion pump back on.a. Reopen the white knob going to the dark green hose.b. If the Robin has cold water going to it, adjust the water flow so that water is going to

both chambers.c. Turn the white knob going to the light green hose halfway between open and closed.

Note: It takes a couple minutes for the water to re-channel. Let it run for a few minutes then come back and make sure the water is channeled correctly, especially if channeling water to the Robin.

13. Take down the fireman’s blankets and put them away after everything has cooled.14. Put away the standing heaters and their stands.15. Take down the hanging heater and put it away.16. Take down the frame and put it away.17. Put all electronics and equipment back and reconnect all cables. See the “Cable Connections to

Everything Else” document for additional help.

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Appendix

Figure 1: Main Chamber Valve

Figure 3: Poppit Valve

Figure 5: Roughing Line

Figure 7: GHS Leak Valve

Figure 2: Ion Gun Leak Valve

Figure 4: Roughing Line Valve

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Figure 6: Century Valve

Figure 8: Vladimir's Ammeter Box

Figure 2: Deuterium Lamp Power Supply

Figure 31: Sciencetech Power Supply

Figure 43: Photoyield Setup

Figure 55: Heed Gun: Valve

Figure 60: HEED Gun: Handle

Figure 72: HEED Gun: Deflection Control Cable

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Figure 84: HEED Gun: Alignment Control Cable

Figure 9: HEED Gun: Blanker Cable

Figure 10: HEED Gun: Interlock Cable

Figure 119: HEED Gun: Power-in Cone

Figure 21: HEED Gun: Blanker Box

Figure 123: Patch Panel Computer

Figure 138: Keithley 230

Figure 140: Keithley 619

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Figure 152: Oscilloscope Generator

Figure 16: Pulse Generator

Figure 17: Grid/Collector Switch Box

Figure 187: Bakeout Heater Master Switch

Figure 199: Bakeout Heater Light

Figure 31: Thermocouple Selector

Figure 206: Thermocouple Location Key

Figure 28: Ion Pump Heater Switch

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Figure 210: RGS Control B

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Bakeout from Vacuum: No PumpdownCable Connections

Cleaning InstructionsFlushing Gas Handling System

Heed: ConditioningHeed: Taking Data

Ion YieldsMiscellaneous Pump InfoPartial Pressure Analyzer

Picture GuidePulsed Yields

Pumpdown: No BakeoutSample Prep

STAIB: Gun ConditioningSTAIB: Gun dataVacuum Break

Vladimir’s Box Key