04-548 dual anode X-ray source area of illumination (excitation)

This blog post includes a video that demonstrates the area of illumination for a PHI 04-548 dual anode X-ray source. That is, where the X-rays hit the sample.

The 04-548 dual anode source typically has one anode side that is Mg and the other side is Al. The older XPS systems that have an 04-548 X-ray source use a lens on the input to the SCA (Spherical Capacitor Analyzer) which determines the analysis area. For example the PHI 5600 XPS system can analyze areas as large as 10mm X 4mm down to 75uM.

The actual illumination area of the 04-548 dual anode X-ray source is quite large as shown in this video – 04-548 X-ray source illumination area.

Today’s state of the art XPS systems focus a small electron beam onto an aluminum target in conjunction with a mono-chromator to excite a very small area on the sample. Rather than exciting a very large area, today’s XPS systems excite a very small area. Down to just a few microns which make it possible to image the sample and analyze surface defects.

32-095 and 32-096 X-ray source control faulty capacitor – urgent!

Recently, I have seen the same problem on several 32-095 and 32-096 X-ray source controls which are used on older Physical Electronics PHI X-ray photo electron spectroscopy systems.

The issue is that C9, a 680 uF electrolytic capacitor blows out and the electrolytic material leaks out on the board.  Left unattended, the electrolytic etches and oxidizes the traces on the board.

If you have an older PHI XPS system that uses a 32-095 or 32-095 X-ray source control you should pull if out of the rack, remove the cover and inspect the board immediately.

If corrosion is present, then remove the board and remove C9.  Note the polarity of C9 as the + indicator on the board may be etched away.  Then, carefully clean the corrosion from the board as best as you can.   If in the shop I use some Alconox and let it sit on the board for a while, then rinse with DI water and let the board dry overnight.   In the field I have used isopropanol or methanol and cotton swabs.    Note that if the traces are corroded badly then they may come off the board as you clean it.  If so, you will need to use some fine copper wire to rebuild the traces.

Once the board is clean and dry, replace C9 with a new one.  I will dig into this issue some more and try to determine why this problem occurs so often and come up with a permanent solution.  In the meantime, I would recommend that the C9 capacitor be replaced every 5 years.

The pictures below show where C9 is located on the control board and what the corrosion looks like.

C9 removed
C9 location
C9 Neg towards connector

04-500 Old style X-ray source filament conversion

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

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 04-500

Old Style 04-500 X-ray source

new 04-500

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.

Contact RBD Instruments for more information.