A blog on the repair, operation and calibration of surface analysis systems and components including electron spectrometers, sputter ion guns and vacuum related hardware. Click on the Index tab below to see a list of all posts. Visit our website at http://www.rbdinstruments.com
Category Archives: X-ray Sources
Information on PHI (Physical Electronics) x-ray source repair, maintenance, and operation
The very early PHI 04-500 and 04-548 X-ray sources used a small filament that had couplers to make the connection between the X-ray source and the filament.
04-500 04-548 old style filament
In addition, the couplers were held in place with a notched ceramic that had a special pointed set screw which pressed into a copper wire that in turn made the connection to the electrical feedthrough on the source.
This connection scheme worked well enough as long as you set the filaments properly and did not ramp the current up too quickly. Even then, the filaments were prone to warping out of shape over time. Also the couplers could loosen up and then the filaments would short out.
PHI’s solution was to redesign the filament where the filaments were brazed into a ceramic base instead of using couplers. This resulted in a very stable filament base where the filaments can’t move at all and so they no longer warped out of position (unless you ran the filament current up too quickly).
Recently I updated an older 04-500 X-ray source from the old style to the new style filaments. You can see the before and after in the pictures below.
Old Style 04-500 X-ray source
Updated 04-500 X-ray source
This update will result in more stable X-ray source operation and extended filament lifetime.
The new style filaments cost more than the old style filaments by quite a bit. But factoring in the improved performance, longer lifetime and reduced downtime it may be worth the additional cost.
If you have an old style source please keep this filament conversion in mind the next time you need filaments or a complete source rebuild.
In a previous post we showed you how to remove dust from the radiator in a 16-020 or 16-050 X-ray source heat exchanger
For this post we will replace the flow switch, which is used in a 16-050 heat exchanger, and also replace all of the water lines. The water lines in this particular heat exchanger have become green with contamination from long term corrosion of the fittings and copper X-ray source anode.
We will remove the motor and pump as part of the hose replacement procedure and will also clean and lubricate the pump to motor connection.
This procedure will take about 2 hours. The replacement hose should be clear reinforced braided tubing that is 5/8” OD and 3/8” ID. This type of hose is available from Home Depot, McMaster-Carr, and Grainger. Measure the length of the existing water lines and then add another 10 feet for the16-050 lines. You may be able to get by with 50 feet but a100 foot roll at Home Depot is only about $50.00.
You will also need 3 gallons of distilled water from a grocery store
First of all, drain as much water as possible out of the water lines. Here is the best way to do that –
Turn OFF the 16-050 OFF and also unplug the power cord from the back of the system. Remove the top cover on the 16-050 and also remove the electrical cover that is located in front left hand corner of the 16-050.
Locate the Crydom Power On relay under the switch cover.
Double check that the power cord to the 16-050 is unplugged.
Move the black output wire from pin one to pin two. Both black output wires should be on pin two.
move wire from here
move wire to here
Remove the quick disconnects from the X-ray source and plug them into the ends of the IN and OUT water lines that connect to the 16-050. That way, when you turn on the 16-050 one line will have water coming out and the other one will have air going into it.
Plug the 16-050 power cord back in. Hold the water lines over a water tight pail (a plastic garbage container will work well). When you turn the 16-050 switch back ON, the water will flow out of the end of the water lines.
Turn the switch breaker OFF when the water stops flowing and is mostly spurting air.
(Note, if you have a 16-020 heat exchanger move the Pump power cord to the HV receptacle and the you can control the pump by turning the circuit breaker ON and OFF)
Unplug the 16-050 power cord.
Remove the side covers on the 16-050.
Remove the DI cartridge and water filter. Note the position of the cartridges so that you can replace them in the same locations later.
Remove the pump from the motor (one screw and a clamp) and set it aside. You do not need to disconnect the wires.
Remove the fan (the outer screws in the square metal fan support).
Next, remove the radiator.
Clean the radiator by flushing it with some Alconox or other detergent followed by a thorough rinse out with warm water.
Clean the cooling fins as needed.
Reinstall the radiator
Replace all the water lines one at a time. Remove a line by unscrewing the hose clamps and twisting the hose off the connector. If the connector has barbs on it you will need to cut a slit in the hose with a box cutter or utility knife. Use the old hose section to measure the length of replacement hose then cut the new hose to the same length. Feel free to make the new hoses slightly shorter or longer if that will make it fit better.
Also, to soften the line and make it easier to slide over a barbed connector, dip the line in Acetone for about 20 seconds. This works quite well. You could also heat the line with a heat gun on the low heat setting for a few seconds.
When you get to the flow switch, unscrew the two front panel screws and pull the flow switch away from the fort panel. If you are going to replace the flow switch, now is the time. You may need to pull some blanking plugs off of the old flow switch. Make sure that you put the new flow switch on exactly the same way that the old one comes off as that is very important for the water flow direction. Take a picture with your phone before you remove the lines for reference. Also note the location of the wires in the terminal strip.
Note that the 220VAC version of the flow switch is no longer made and so in a 16-050 you would also need a 220VAC to 120VAC step down transformer. Contact RBD Instruments if you need a replacement flow switch.
Step down transformer mounted in 16-050
After all of the water lines have been replaced, remove the quick disconnects from the water lines and plug the water lines together.
Reinstall the DI and water filter cartridges. You should replace both the De-ionizer and filter cartridges if it has been a while (a few years) since the last time you replaced them. If you replaced the x-ray anode in a 10-610 mono source as part of this maintenance then the deionizer cartridge MUST be replaced. Contact RBD Instruments if you need a deionizer cartridge or water filter.
Reinstall the motor.
Inspect the water pump and clean and lubricate (with grease) as necessary. The motor to pump connection can get a lot of debris and some rust accumulation.
Reattach the pump to the motor.
Put one gallon of fresh distilled water (from a grocery store, not lab DI) into the reservoir.
Plug in the 16-050 power cord.
Turn on the 16-050.
Immediately add another gallon of fresh DI water into the resistor as the water will be filling the lines and cartridges.
Check for leaks and tighten hose clamps as needed.
Add more water as needed until the level is correct on the back of the 16-050. It will take 3 to 3.5 gallons. Give it some time for the cartridges to fill up, about 10 to 15 minutes before you do a final top off.
If you have replaced the flow switch you can monitor pins 1 to 5 on the Coolant ON/OFF connector with an ohmmeter. With the 16-050 on and water flowing, adjust the potentiometer on the flow switch until the resistance between pins 1 and 5 drops down to 1 ohm or less.
Reconnect the Coolant ON/OFF cable.
Turn off the power to the 16-050 and unplug the power cord from the back of the system.
Confirm that the power cord is unplugged.
Move the wire on the terminal block form pin two back to pin one.
Replace the electrical cover.
Replace the side covers.
Replace the top cover.
Plug the 16-050 back in and turn on the power switch.
The 16-050 should turn on and off when the 32-095/6 is turned off and on.
Turn off the 32-095/6 and then reconnect the water lines to the X-ray source.
The heat exchanger cooling fan used on the Physical electronics 16-025 and 16-050 heat exchangers which are used to cool the x-ray sources on an XPS system can run slowly as the fan motor ages once the bearing lubricant begins to dry up. The result of a slow fan is that the anode will run warmer than normal and possibly melt. At a minimum reduced cooling will shorten the anode lifetime. The 16-020 heat exchanger has a fan that is attached to the pump motor, so it will not have this problem unless the pump motor fails.
The symptom for a slow heat exchanger fan is that with the source at full power after 20 minutes of operation the water lines to the x-ray source will be very warm or even hot rather than slightly warm.
To test the fan you can feel how much air is coming out the back side of the radiator when the 16-025 or 16-050 heat exchanger is on. The radiator will slow down the airflow, but it should still be a reasonable amount of air that escapes out the back side of the radiator. If the fan looks like it is spinning slowly and there is minimal airflow then the fan should be replaced.
If you want to test the actual RPMs of the fan you can use a non-contact laser tachometer (available for as little as $15.00). Or you can use an audio method as shown in this video on YouTube that uses Audacity:
It is held in place with some radiator mounting rods that are available at most auto parts stores. Look for Hayden Nylon mounting rods with vibration pads.
Nylon mounting rods
In addition to the cooling fan, if the pressure indicator on your 16-050 heat exchanger bounces during operation you should consider replacing the water pump as well. RBD Instruments provides the water pumps. The 16-020 and most 16-025 heat exchangers do not have a pressure gauge.
And of course, make sure that the radiator is free from dust as being covered with dust will also reduce the cooling efficiency of the 16-020, 16-025 or 16-050 heat exchangers. Refer to the RBD TechSpot post Heat Exchanger Preventive Maintenance for more information on dust and the radiator.
Heat exchanger preventive maintenance will prolong the anode lifetime on your 10-610 mono chromator anode and prevent a costly and time consuming anode meltdown.