Category Archives: General Optics and Vacuum

General information on repair, maintenance, and operation of both PHI (Physical Electronics) and other manufacturers’ systems and components

Contact issue with MCD ceramic on PHI 5600 XPS system

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This blog post will show you how to repair a damaged 16 channel MCD anode ceramic on a PHI 5600 X-ray Photoelectron Spectrometer system.

The MCD anode ceramic is part of the MCD (multi channel detector) assembly. The anode ceramic has 16 channels where electrons with slightly different energies are counted. The 16 channel detector offers a higher count rate as compared to the PSD (position sensitive detector) and single channel electron multipliers that were used on earlier XPS systems.

There are surface mount resistors on the MCD anode ceramic that couple the positive (POS) voltage to the individual channel output ceramics. One of these surface mount resistors in particular provides the pathway for the multiplier POS voltage to the channel (chevron) plates. The POS contact is on both sides of the ceramic and they are connected via a gold plated through hole.

It is possible that over time (or when the chevron plates are replaced) that the gold plated pad can become electrically open in which case there would be no voltage applied to the chevron plates and, therefor, no XPS signal.

The picture below shows the location of the POS voltage gold plated through hole.

In this case, the gold was worn away from the gold plated through hole which resulted in an open circuit and no data. The picture below shows a close up of the gold plated through hole and the open area on the ceramic.

Besides not getting any data this problem was also evident as the resistance between the POS and NEG connections was open instead of the normal 15 to 20 meg ohms.

A new MCD anode ceramic costs about $700.00 and so I decided to first try and repair the contact using a thin strip of oxygen free copper foil

First I used a ceramic cutting wheel to flatten out the out edge of the ceramic to make room for the copper foil. Then I cut the small piece of copper foil so that it would cover the pad by the resistor and then be able to bend over the other side of the ceramic so that it could contact the outer gold ring. I pressed the copper so that it would be as flat as possible. Since there is a contact on both sides of the ceramic in the areas that the copper foil will cover, those contacts will hold the copper foil in place.

After reassembling the MCD assembly the multiplier POS to NEG resistance was 20 meg ohms, which is correct.

This repair method works well if you do not have a replacement MCD ceramic handy.

The PHI part number for the 16 channel anode ceramic is 619102 and the price as of January 2025 is $729.00

For more information on installing the Chevron plates into the MCD assembly refer to this blog post – https://www.rbdinstruments.com/blog/5600-xps-system-mcd-channel-plate-replacement-procedure/

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

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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.

16-020 heat exchanger 12″ deionizer cartridge issue

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The 16-020 heat exchangers are used with the older Physical Electronics (PHI) 5100 through 5400 X-ray photo-electron spectrometer (XPS) systems.The 16-020 has a built-in deionizer cartridge (and a particle filter) which keeps the water in the closed loop system clean and it also keeps the resistance of the water high. 

The original deionizer cartridges were blue and had a recess in the bottom of the filter that matched up with a plastic guide on the bottom of the Millipore housing.  Those blue deionizer cartridges are no longer available. The new replacement deionizer cartridges do not have a recess on the bottom.

When a new deionizer cartridge is used with the original Millipore housing the plastic guide on the bottom of the housing will push up on the bottom of the deionizer.  This makes it difficult if not impossible to fully screw on the housing.  It also puts pressure on the bottom of the deionizer cartridge which can rupture the bottom of the deionizer and cause the media particles to leak out, potentially causing an issue with the water flow and or damage the pump and lead to a catastrophic anode melt down. There are two ways to solve this fit issue. One is to cut and grind out the top part of the guide on the original Millipore housing. To do that you need to remove the plug on the bottom of the housing and then use a drill or cutting wheel that is mounted on a drill extension. The pictures below show a housing before and after modification.

 

The other option is to replace the original Millipore housing with new housing that correctly fits the new deionizer cartridge. But if you replace the housing you will also need to replace the manifold as the new manifold will not fit into the original Millipore manifold.

RBD Instruments provides both deionizer cartridges and housings. If you have the original Millipore housing on your 12” deionizer cartridge then I recommend that you inspect it to see whether the guide on the bottom has been cut down or not.  If not, you should cut it down or replace the housing.  

If the deionizer is ruptured then the entire cooling system (reservoir, pump, water lines and source) needs to be inspected and flushed out.This problem is an issue only with the 12″ deionizer cartridge on the 16-020 heat exchangers. 

The 16-050 heat exchanger that is used on the 5600 and up XPS systems has a 10″ deionizer cartridge.

Not sure if you need to replace your deionizer cartridge?  Just run up the high voltage on your X-ray source to 15kV but do not set an power to the X-ray source.   Observe the emission current reading on the HV supply.  If the deionizer is good the reading will be 1-2 mA.  Once the leakage current gets up to 3-4 mA at 15kV you should plan on replacing the deionizer cartridge and particle filter soon.  If the leakage current at 15kV is 5 mA or higher you should replace the deionizer and particle filter and also flush out the water with new distilled water from a grocery store.  Lab distilled water does not always work but grocery store distilled water works every time.

Contact RBD Instruments to order the deionizer and particle filter.