15-255G Filament Change Procedure

Posted on May 9, 2015 by Randy

This post explains how to replace the C75-010 tungsten filament used in the Physical Electronics 15-255G double pass CMA. Refer to the pictures below for more details. RBD Instruments provides the C75-010 filaments as well as any other parts that you may need for your 15-255G analyzer. We also offer a complete analyzer rebuild service that includes a new filament and electron multiplier.

15-255G Filament Change Procedure

Use gloves, de-magnetize all tools and clean all tools with Isopropanol. Set up a work area with UHV aluminum foil. Or use regular aluminum foil and clean it with isopropanol.

Set analyzer on stand or use manuals and support analyzer on handles, facing up.

Remove outer magnetic shield (3 screws)
Remove inner magnetic shield (4 screws)
Carefully remove conical ceramic cover. Note that sometimes the conical ceramic will stick inside the cover. Be careful not to let it fall out if it does stick. If it falls out an breaks a replacement conical ceramic is expensive!
Remove conical ceramic and carefully set it on the aluminum foil.
Carefully lift inner cylinder up and off of the electron gun assembly. Note: If the inner cylinder does not move freely, use a heat gun to expand the inner cylinder so that it will slide off. Do not force it! Be careful not to damage the grids.
Look at the electron gun detail to familiarize yourself with the electron gun assembly.
Remove the deflection cover (3 small flat head screws)
Remove the deflection support screws (4 flat head)
Remove the deflection support post that is located between the two ceramic posts.
Tilt the electron gun out and down so that you can access the bottom plate of the electron gun.
Remove the three long screws that hold the electron gun assembly together.
Remove the V1 emission screw
Remove the 2 filament couplers from the filament posts. You will need a .048 4 spline wrench.
Remove the 3 filament support ceramics.
Remove the filament whenelt cap assembly. Note the orientation of the emission tab and filament posts as when you put the new filament in it will need to have the same orientation.
Remove the 3 screws that hold the filament base on and remove the filament.
Install the new filament in the same orientation as the old filament into the emission cap.
Install the 3 screws and the filament base and tighten slightly.
Position the filament so that it is centered in the hole and tighten the 3 screws. This is best done using a microscope. For best results the tip of the filament should be perfectly centered.
Install the filament assembly on top of the 3 filament support ceramics and use the 3 long screws to hold the assembly together. The three long screws need to be tightened firmly so that they all have the same distance with respect to the base.
Reconnect the V1 wire
Reconnect the filament couplers.
Install the deflection support post, screws and cover.
Ohm out the connections to the filament and V1.
Degauss the gun assembly.
Install the inner cylinder over the electron gun assembly. Line up the dead spots on the ceramic tubes.
Reinstall the upper outer cylinder.
Carefully install the conical ceramic. The resistor part should be 180 degrees out from the center flat ceramic. Ohm out OC (outer cylinder) to ground and make sure it has the correct resistance of 600 k ohms +/- 100 k ohms.
Install the conical cover and tighten the screws firmly and evenly.
Install the inner magnetic shield
Degauss the analyzer.
Install the outer magnetic shield.
Degauss the analyzer. Installation complete.

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Deionizer flow restrictor

Posted on April 25, 2015 by Randy

Deionizer flow restrictor for PHI X-ray source heat exchangers

This post is a reprint of a tech tip that we published in our fall 2008 Service Detail newsletter. This exact problem came up recently and so I thought I would resurrect this tech tip for educational purposes. In the recent case we knew that the leakage current was very high and it had been several years since the deionizer cartridge was replaced. Replacing the deionizer cartridge was the logical solution. Replacing the cartridge did solve the problem for a while, but within a very short time the leakage current problem returned. Cleaning out the flow restrictor as described below solved the problem.

If you need replacement water filters or deionizer cartridges for your PHI 16-020 or 16-050 X-ray source heat exchangers that are available at this link – PHI Optics Parts

Deionizer flow restrictor inspection and cleaning procedure:

The 04-500 and 04-548 15kV dual anode x-ray sources are water cooled by a closed loop radiant heat exchanger (model 16-020, 16-050) which includes a built in water filter and deionizer cartridge. Since the anode floats at 15kV, the water must be kept in a constant state of deionization to prevent leakage current. If the leakage current is more than 2 or 3 mA at 15kV of high voltage then the leakage current will start to affect the power regulation on the 32-095 or 32-096 X-ray source control. Normal leakage current (the current that is shown on the HV supply current meter when only the high voltage and no power is applied) should be less than 2mA @ 15kV. Once you get up to 3 to 5mA it is time to replace the water filter and deionizer cartridge. If the leakage is very high (10mA or more) then it is possible that the heat exchanger flow restrictor is plugged up.

Part of the loop in the cooling flow directs about 10% of the water through the deionizer and filter. There is a flow restrictor just in front of the input to the filter and this flow restrictor can become clogged or corroded over time, resulting in reduced flow to the deionizer cartridge and subsequent increased leakage current.

It is recommended that every time you replace the deionizer cartridge and filter (about once every 3 years is typical) that you inspect the flow restrictor and clean it out if necessary. If it is corroded you may need to drill it out with a tiny drill bit (about .030″).

The pictures below show the location of the flow restrictor and how to remove it for inspection. If it is plugged up then drill it out with a small drill bit and clean it before reinstalling it into the flow restrictor connector

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5600 XPS analyzer voltages

Posted on April 22, 2015 by Randy

One of the more common questions that we get when a PHI 5500 or 5600 XPS system loses the ability to collect data, is – “how can we test the analyzer voltages?” This post will explain the procedure in detail.

First though, the disclaimers –

#1 This procedure involves measuring potentially lethal voltages and is to be performed only by personnel property trained to work safely with high voltage.

#2 It is recommended that these measurements be taken using a Fluke 80K-40 high voltage probe or equivalent. The impedance of the 80-40K is high enough that it will not load down the 80-365/66 analyzer control voltages which will be measured during this test procedure.

Procedure

Turn off the card rack power
Remove the filter box from the analyzer by loosening the two 9/16″ bolts and then sliding the preamp off the SCA connector. Do not remove the black high voltage cable that is connected to the filter box.
Remove the 6 screws and take the cover off the filter box.
Position the filter box so that you can get to the connection points shown in the photos below.
Connect a jumper clip from the filter box chassis to the vacuum chamber. This will ensure that the filter box is grounded.
Connect the ground lead of the high voltage probe to the vacuum chamber, and the input end of the high voltage probe to the E7 IS test point in the filter box. The test points are hard to get to so you may need to use a small alligator or Pomona clip for the connection point inside the filter box and then connect the other end of the clip to the high voltage probe input.
Refer to the table below.
Turn on the card rack power and set up an alignment with a upper limit and lower limit of 1000eV. For any given pass energy voltages are shown for the inner cylinder ((IS), the mid-ring (MR), the outer cylinder (OC), the Retard voltage (V Ret), Lens 2 (L2), Lens 3 (L3) and the pass energy (V PE) with respect to ground. Values are shown for both Mg and Al anode energies. (Note that the CTL and FWD lens voltages are also included in the table. The CTL and FCL lens voltages are measured at the end of the CTL and FCL cables, not in the filter box.)
Select a few pass energies and measure and write down the voltages at all of the test points. By comparing the results of your measurements to the values in the table you can determine of any of the supplies may have a problem. Typically the voltages measured should be within 10 volts of the values in the table. If you have a problem with one or more of the supplies the measurement voltages will be off by a significant amount.
If you do find that there are some incorrect voltages then your qualified technician can use the calibration procedure in the 80-365 or 80-366 manual as a guide to help isolate the problem to the component level. If you do not have the necessary resources to troubleshoot the problem to the component level please contact RBD Instruments for repair options.

MULTIPLIER VOLTAGE TIP: Not listed in the table is the electron multiplier voltage. To test the multiplier voltage, remove the NEG and POS filter box covers and connect the high voltage probe clips between the resistors inside the multiplier NEG and POS filter boxes. Make the connections to the high voltage probe with the card rack power OFF. When acquiring data the multiplier voltage should be within 10V of the value that the multiplier is set to in the software.

Mg
Pass Energy (eV)	IS (E7)	MR (E8)	OS (E9)	VRet (E3)	L2 (E10)	L3 (E11)	V PE (E1)
2.95	-245.7	-246.7	-247.4	-249.7	-174.3	-209.7	-245.7
5.85	-241.8	-243.7	-245.1	-249.7	-214.0	-87.7	-241.7
11.75	-233.8	-237.6	-240.5	-249.7	-192.1	123.3	-233.6
23.5	-218.0	-225.6	-231.4	-249.7	-174.4	240.3	-217.6
29.35	-210.1	-219.6	-226.8	-249.7	-165.6	316.3	-209.6
46.95	-186.3	-201.5	-213.1	-249.7	-144.4	514.3	-185.5
58.7	-170.5	-189.5	-203.9	-249.7	-135.6	591.3	-169.4
93.9	-123.0	-153.4	-176.5	-249.7	-92.4	925.3	-121.3
117.4	-91.3	-129.3	-158.2	-249.7	-76.1	1082.3	-89.2
187.85	3.8	-57.0	-103.3	-249.7	-23.9	1625.3	7.2

				Mode	CTL	FCL
Mg source	1253.6			Minimum	-117.4	819.0
Work function	3.9			Small area	-187.3	-192.3
All voltage respective to ground				Large area	-209.7	0.0
BE set to	1000			Small aper	-123.6	819.0



Al
Pass Energy (eV)	IS (E7)	MR (E8)	OS (E9)	VRet (E3)	L2 (E10)	L3 (E11)	V PE (E1)
2.95	-478.7	-479.7	-480.4	-482.7	-336.9	-442.7	-478.7
5.85	-474.8	-476.7	-478.1	-482.7	-429.5	-320.7	-474.7
11.75	-466.8	-470.6	-473.5	-482.7	-408.3	-109.7	-466.6
23.5	-451.0	-458.6	-464.4	-482.7	-392.0	7.3	-450.6
29.35	-443.1	-452.6	-459.8	-482.7	-383.2	83.3	-442.6
46.95	-419.3	-434.5	-446.1	-482.7	-362.0	281.3	-418.5
58.7	-403.5	-422.5	-436.9	-482.7	-353.2	358.3	-402.4
93.9	-356.0	-386.4	-409.5	-482.7	-311.6	692.3	-354.3
117.4	-324.3	-362.3	-391.2	-482.7	-291.4	849.3	-322.2
187.85	-229.2	-290.0	-336.3	-482.7	-229.6	1392.3	-225.8

				Mode	CTL	FCL
Al source	1486.6			Minimum	-226.9	1583.3
Work function	3.9			Small area	-362.0	-371.7
All voltage respective to ground				Large area	-405.5	0.0
BE set to	1000			Small aper	-238.9	1583.3