Always make sure that the filament is indeed blown by trying to bring up the filament one more time. The SX-51 has been known on occasion to simulate a blown filament by shutting down the high voltage. To check, simply type :
SX> setu hv15
If the filament does come up properly there is no need to change it. If, on the other hand, the SXLocal window again reports "filament out" or "anomaly of gun current" then the filament probably really is blown.
In that case, from the SXLocal window type :
SX> heat off
SX> hv off
SX> vent gun
Execute (abort=^z)
Confirm the vent operation by hitting <Enter> again and wait until you see :
Turn gun valve to position 1
Now turn the gun valve to position 1 (2 > 3 > 1). You will see :
Gun valve ready
Activate manual valve for gun air inlet
Now turn the black lever on the gun valve assembly forward until you hear a "click". You will see :
Manual valve ready
Gun air inlet activated
If the filament just burned out, you may want to wait about an hour for it to cool down if you are not in a terrible rush. If you decide to go ahead and change the hot filament BE CAREFUL NOT TO MELT A PLASTIC GLOVE on the hot metal parts.
Next, lift the gun assembly by first unscrewing the four large socket head screws from the top of the gun. Place them to one side on the table. Then, open the gun chamber on it's hinge. Allow the grounding arm to contact the Whenelt assembly to prevent any possibility of a shock hazard and then push it to one side.
Get a pair of plastic gloves. The gun chamber must be kept clean and dust free for the microprobe to function properly.
Unscrew the whenelt cap (using several layers of Kim-wipes for thermal insulation if it is hot) and place on a clean surface. Remove the small interface ring. Grasp the whenelt assembly (it may be really hot!) and pull to remove.
Next, take the spare pre-built whenelt assembly and observing the slotted key, insert carefully until it is firmly seated. Place the interface ring back on and screw the whenelt cap back on until tight.
Remove your gloves and close the gun chamber. Take the four socket head bolts and drop them in and start them 1 or 2 turns only (DO NOT TIGHTEN YET).
If the length of time the gun is vented is extended, the SXLocal window may issue the prompt :
Close manual valve
In this case, close the manual valve by pushing the black button in and turning the lever up on the side of the gun valve assembly until you hear a "click".
From the SXLocal window type :
SX> pump
You will see:
Activate manual valve for gun primary pump
Pull the lever forward on the side of the gun valve assembly and you should see the message :
Manual valve ready
Wait until you see :
Close manual valve
Close the manual valve by black button in and turning the lever up on the side of the gun valve assembly until you hear a "click". You should see the message :
Manual valve ready
Wait until you see :
Turn gun valve to position 3
Now turn the gun valve (1 > 3) to position 3 and you should see the message :
Gun valve ready
Next tighten the four socket head bolts in a cross pattern so that they are tightened evenly.
Wait until you see the message :
Turn gun valve to position 2
Turn the gun valve to position 2 and then wait until you see the message :
Vacuum ready
Now bring up the beam manually is steps. Begin by setting the high voltage and setting the heat to 150 by typing :
SX> hv 15
SX> heat 150
SX> mag 50000
SX> gun
Wait 40 minutes or so and then bring the heat up 10 units at a time until you the heat is 215 to 220. Do not exceed a heat value of 225. The filament should now be over-saturated and ready for alignment.
Then, from the SXLocal window type :
SX> gun clear
SX> gun auto
When the gun auto alignment has completed check the condenser lens values. The "xhi" and "yhi" values should be between -1000 and +1000. The "xlo" and "ylo" values should be between -200 and +200. The closer to zero, the better the filament is aligned, and therefore the longer it will last (in general).
Next, check the filament for proper saturation by typing :
SX> heat
And adjust the heat value until the filament saturation plateau is located (normally between 200 and 210 for a new filament).
Then on a fluorescent sample (MgO or Benitoite) check that the aperture is correctly aligned by turning off the light and adjusting the fast focus thumbwheel.
From the SXLocal window type :
SX> foc fast
Allow the new filament to warm up for an hour or two and then check the saturation plateau again to see if it has drifted. Perform another gun auto command and check that they are similar to the first set. Lastly, if everything looks good, set the beam current and save the gun alignment by typing :
SX>cur 20
SX> setu hv15 save
Be sure to note in the filament log the date and gun and saturation values for the new filament. Place the old whenelt in the plastic box for protection and leave a note to remind me to rebuild it.
END
If the filament just burned out, you may want to wait about an hour for it to cool down, if you are not in a terrible rush. If you decide to go ahead and rebuild the hot filament, BE CAREFUL NOT TO MELT A PLASTIC GLOVE on the hot metal parts.
Put on a new pair of plastic gloves. Place the whenelt assembly on a clean piece of Kim-wipe on the sample preparation pad.
1. Remove the filament backing piece using the 2 holed end of the special Whenelt tool.
2. Gently remove the filament assembly and backing piece and check to see if the filament is actually broken by holding it under a bright light and then gently touch one side of the wire with a small screwdriver to see if the wire is broken. If so, place the filament in the acrylic filament case marked "Used".
If the filament is not blown, check for continuity using a VOM meter and if the filament still appears OK, set it aside for closer inspection.
3. Using a gloved finger, unscrew the filament support piece and set to one side.
4. Using a jewelers screwdriver, back out the filament centering screws until they are flush with the inside of the whenelt housing.
5. Using the ridged end of the special Whenelt tool, remove the aperture backing ring.
6. Remove the aperture disc and inspect. If both sides of the aperture disc are dirty, clean the disc using metal polish. Be sure to carefully clean the inside of the aperture hole using the broken end of a wooden cotton tipped swab.
Rinse and wipe several times with alcohol until all traces of metal polish have been cleaned off. Inspect carefully for any oxide residue and repeat the cleaning using the metal polish if necessary. Otherwise, clean the disc again using clean alcohol and the ultra-sonic cleaner. Dry the aperture disc using a Kim-wipe.
Throw away the old plastic gloves and change to clean gloves. Use a "Duster" to make sure that no lint or foreign material is inside the Whenelt housing. Inspect carefully under a bright light.
7. Replace the aperture disc in the whenelt housing. If only one side of the aperture has been oxidized, insert the aperture disc so that the oxidized side is facing out (away from the filament). Screw the aperture backing ring into the Whenelt housing using a gloved finger making sure that the wider slot is visible. Use the ridged end of the Whenelt tool to tighten the aperture backing ring.
8. Screw in the filament support piece until the outside end is flush with the back of the Whenelt housing.
9. Tighten the 4 centering screws until the filament support piece is tight. Obtain a new filament assembly from the acrylic case marked "New" and placing the filament on the filament backing ring carefully insert both pieces into the Whenelt housing and screw into place. Tighten the filament backing ring using the two holed end of the Whenelt tool making sure that the notch is engaged.
10. Loosen the four centering screws and adjust the height of the filament tip until it is perfectly even with the outside edge of the aperture disc.
11. Unscrew the filament backing ring 1 turn (use notch for reference) to obtain the correct filament gap.
12. Using the 4 centering screws, center the filament until it is exactly centered as viewed in the aperture disc. Place the rebuilt Whenelt assembly in the plastic case along with the Whenelt tool.
END
1. To remove a sample from the microprobe, first type the following commands from the SXLocal terminal emulation window :
SX> heat stan ! places filament in standby mode (heat to 150)
SX> vacu stat ! view vacuum status
SX> arlk ! pump air lock out for sample exchange
You will see:
Execute (abort = ^Z)? ! system requires confirmation, type <enter>
Hv off ! system turns off high voltage
Turn gun valve to position 1 ! manually rotate gun valve (2>3>1) to closed
Gun valve ready ! system confirms gun valve closed
Airlock backup complete ! after 1-2 minutes system confirms air lock ready
2. Next, turn
the extraction handle on the airlock to the extract symbol 
Open the airlock (push airlock handle in and swing up). Note that handle locks and rotates slightly.
Push extraction handle in all the way, then pull out to remove sample block.
Close the airlock (rotate handle and swing down). Note that handle locks and moves out slightly.
3. Now, from the SXLocal window type :
SX> pump ! vent airlock chamber
After a minute or so, the airlock is vented. Open the airlock door by depressing the latch button and remove the sample cassette by pushing the sample block onto the extraction handle until it clicks and releases the sample block.
4. Change the samples as needed on the sample preparation pad :
Place the sample on the sample preparation pad and change samples and standard mounts as necessary. Be sure to document sample placement and identification by filling out the sample mount map in one of the 3 ring binders.
Be sure to orient the sample block correctly. The small hole goes to the front of the sample mount. See the sample location chart for the correct orientation.
5. Place the prepared sample block back in the airlock :
When ready, open the airlock door (depress the
spring latch) and turn the extraction handle to the insert symbol
. Then
slide the sample block onto the extraction handle rails until it
clicks.
Close the airlock door. During this time, the system may request that the gun valve be turned to position 2. If this is requested, turn the gun valve to position 2 and wait for the Vacuum ready message, if not, then the arlk command can be given immediately.
6. When ready, type the following command to pump out the airlock :
SX> arlk ! pump out airlock chamber
You will see :
Execute (abort=^Z)? ! system requires confirmation, type <enter>
Hv off ! system turns off high voltage
Turn gun valve to position 1 ! manually rotate gun valve (2>3>1) to closed
Gun valve ready ! system confirms gun valve ready
Airlock backup complete ! after 1-2 minutes system confirms air lock ready
Now open the airlock (push airlock handle in and swing up). Note that handle locks and rotates slightly.
Push extraction handle in all the way, then pull the empty extraction handle back out all the way.
Close the airlock (rotate handle and swing down). Note that handle locks and moves out slightly.
7. Now, pump the airlock by typing from the SXLocal window :
SX> pump ! vent airlock chamber and pump out sample
Wait until the system requests that the gun valve be opened.
Turn gun valve to position 2 ! manually rotate gun valve (1<3<2) to open
Wait until you see:
Vacuum ready ! vacuum system is ready
8. Verify the stage coordinates :
SX>mov stag ref ! move to sample block cross hair and adjust
SX>veri stag ! zero stage axes
Move to the MgO standard and restore the beam using the "setu" command. If necessary adjust the filament heat and beam focus.
END
Opening the SXLocal Window
If the SXLocal (CrossTalk) terminal emulation program is not running, start it by double clicking the CrossTalk icon in the Probe for Windows group from Program Manager.
A command to enable task reading and writing to and from the SX processor will be automatically sent to the SX when the terminal emulation window opens. If a command syntax error is seen, exit the SXLocal application and try restarting it again.
If the status line (at the bottom of the window) says that the COM port is busy and could not be opened, the SXLocal application is already running in background. Use the Task manager to bring the application to the foreground.
Verifying the Stage
From the SXLocal window, type :
SX>mov stag ref
If necessary, bring the reflected light optics up. If an optical image of the sample is not visible in the left hand monitor (M1), click the "Light 6" button in the SXLocal window to turn on the sample reflected light.
If the TV camera image is still not visible, check the following items :
- click the Display button on the SXLocal window
- push button B in the M1 monitor recessed control panel (the green cross hair should be visible on M1)
- click the "Refl" button in the SXLocal window
- click the "Light 6" button (again)
- make sure the crossed polarizer is pulled out (over spec #1)
Adjust the stage using the trackball until the cross hair is centered on the sample block reference mark. Then type :
SX>veri stag
This will reset the stage axes to 0,0,0 for a rough translation calibration. Use the import standard or unknown positions using the fiducial translation option in Probe for Windows for a precise calibration.
Bringing the Beam Up
From the SXLocal terminal emulation window, first click the "Start" button at the bottom of the screen and wait 5 or 10 seconds. Once the sample is visible, adjust the stage X, Y and Z using the trackball to a position NOT on epoxy, then type the following command at the terminal prompt :
SX>setu hv15 ! or setu hv20 for a 20 KeV setup
Wait until the Setup Ready message appears in the SXLocal window. Then confirm that the desired operating voltage and beam current is displayed on the right hand monitor (M2).
Starting Probe for Windows
Start Probe for Windows by double clicking it's icon in the Probe for Windows group in Program Manager. When the program asks whether to interface to the microprobe hardware, click Yes. After a few seconds the Confirm Motor/Crystal dialog will show. Simply check that the crystal positions correspond to the ones displayed in the left hand monitor (M1). Click OK to proceed.
To begin, first open an existing run from the File | Open or Find File menus, or open a new run from the File | New menu. Select an existing file or enter a new file name and click OK. The program will prompt for a run title, your name and a sample description. Click OK when done.
Next open the Acquire window by clicking the Acquire! button just below the main window menu bar. The program will ask whether to acquire the nominal beam current (if a new run was started). Click Yes to acquire the nominal beam.
Moving to a Sample
Click the Move button to open the Move Motor/Crystal dialog. Make sure that you are on a fluorescent sample such as MgO or benitoite. You can simply type the X and Y positions from the standard position chart into the Move dialog X and Y fields and click Go, or you can click the Positions button in the Move dialog and select a existing position sample and click Go.
SXLocal Commands :
The following random SXLocal commands are useful :
SX>hv 20 ! sets KeV to 20 kilovolts
SX>cur 20 ! sets the beam current to 20 nA
SX>mag 400 ! sets the beam scan to 400X (63 - 50000 range)
(push button B in the M1 control panel to see SE)
SX>mag 50000 ! sets beam to minimum scan size for analysis
SX>light sample 0 ! turns light off for best BSE image (0 - 9, default is 6)
SX>det on ! turns SE detector on (det off for SE detector off)
SX>focu ! adjust beam focus or mag using thumbwheels
(focu fast for low mag or focu slow for high mag)
SX>mov stag ! restores the trackball after using thumbwheels
SX>size 20 ! set beam diameter to 20 microns (FIX mode)
(beam scan is disabled, use size off to use SE/BSE)
SX>vs2 auto ! set video board two in automatic mode
SX>vs2 manu ! set video board two in manual mode (BSE adjustment)
SX>mode tv ! set beam scan speed to tv video rate
SX>mode anal ! set beam scan speed to slow scan
Advanced SXLocal Commands :
SX>heat ! adjust filament saturation
SX>gun ! adjust electron lens
SX>gun auto ! perform electronic filament alignment
Shutdown procedure
Click the Quit button in the SXLocal window. Turn off room lights, leave and don't the door hit you in the ass on the way out.
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