Category Archives: General Optics and Vacuum

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

32-095 X-ray source control

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When the 32-095 X-ray source control is not working properly there are some easy  possible solutions that you can check before sending the unit to RBD Instruments Inc. for repair.

If the problem is that one filament works but the other one does not, then you should check the fuses located on the filament power supply board inside the 32-095 X-ray source control in the back left hand corner of the unit. (The other possibility is that the x-ray source filament is open.)     With the 32-095 power off, slide the unit out and remove the cover, then measure the resistance on the fuses.  Usually it is easiest to just completely unplug the 32-095 and remove it from the electronics rack.

The fuses are 5 amp slow blow and are shown in the board layout figure below.

filament_board_fuses

Filament power supply board fuses

The next most common problem is instability in the controller or flashing digits on the digital panel meter. These can be caused by high AC ripple on the +/-15V or +5 V supplies on the local power supply board which is located in the front left hand side of the 32-095.

The figure below shows the layout of the local power supply board and the location of the +/-15V and +5V supplies.

local power supply board layout

local power supply board layout

The picture below shows the points where you measure the +5v supply.   To measure the +5V supply, connect your test clips to the pins as shown in the picture below. Turn on the 32-095 power and then measure both the DC and AC voltage using a DVM. The correct value is +5.0 V DC (+/- 100 mV) and the AC ripple should be less than 10mV.   If the +5V supply has a problem the DC will be more like 4V and the AC will be 1 to 2V.  Power supply board problems are usually caused by bad capacitors.

 

32-095 local power supply board +5V

32-095 local power supply board +5V

The pictures below show the test points for the + and – 15V supplies.   The correct voltage values are + and – 15.0V (+/- 200 mV) and the AC ripple should be less than 20mV. If the DC voltage is low and the AC ripple is high then the supply has a problem.

32-095 local power supply board -15V

32-095 local power supply board -15V

32-095 local power supply board +15V

32-095 local power supply board +15V

The figures below show the +5 and +/- 15V local power supply board schematics.

5V schematic

5V schematic

15 V schematic

15 V schematic

 

Below is a table that lists common problems and possible solutions.   Sometimes the problems are easy to fix, but often the problem may be a hard to find bad capacitor, diode or integrated circuit.

Problem Possible solution
No current on one filament Bad power supply board fuse, open filament on source
No filament current but fuse is OK Bad PIC 645 regulator
Unstable operation Bad capacitor on local power supply board

If the problem is not an easy fix then RBD Instruments can repair your 32-095/96 x-ray source control and also provide you with a loaner unit to use while we are repairing yours.

Additional test info:

04-500/548 X-Ray Source Filament Test

The following information is helpful in testing the condition of the filaments in 04-500 or 04-548 15 kV dual anode X-ray sources and in troubleshooting the 32-095 X-ray source control.

 X-Ray Sources

On the big filament connector on the source, pins A and B (filament 1) and C and D (filament 2) should have less than 1 ohm of resistance. All pins should be open to ground.

The HV connector (anode) should be open to ground. Check that with the X-ray high voltage supply OFF and the HV cable to the source disconnected.

32-095 Test

Follow the 32-095 Outgas/Activate procedure in the 32-095 manual.

To bench check the 32-095, short pins A and B on the Pressure Interlock connector, and pins A and E on the Pump Control connector.

You can use two large paper clips as dummy loads when testing the filament current.  Put the clips on the end of the cable or on the filament connector on the back of the 32-095.

32-095 outgas activate test load

High voltage switch connections:

32-095 HV switch connections

Endoscopic ion pump inspection

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An easy way to determine whether or not an ion pump needs to be rebuilt is to perform an endoscopic ion pump inspection. The hard way is to drop the ion pumps.

In the last few years the prices have really come down on USB and android/iPhone endoscopes. If you do a search on EBay for USB endoscope you will see a lot of choices for under $20.00. The one used in this blog post is 7mm in diameter, which is small enough to fit into a 1.33” CF flange hole.

endoscope

endoscope

endoscope_for_phone

endoscope_for_phone

 

 

 

 

 

 

For this example we inspected a PHI 660 scanning auger system equipped with a 220 l/s ion pump. This system has been in use for about 10 years primarily for depth profiling using Argon gas.

Since there is a shield below the TSP filaments the only way into the ion pumps was thru the un-used 1.33 CF flange that is opposite the ion pump high voltage connector.

This video link shows what it looks like as you move the endoscope around inside the ion pump – https://www.youtube.com/watch?v=5DQVW3DCG9A&feature=youtu.be  Note that the video has a blue tint to if from the built in LED camera lighting.

The color corrected pictures below show that the ion pump elements are pitted, the insulating ceramics are coated and there are some flakes in the bottom of the pump well.   The conclusion was that the pump elements have another year or so left on them and so we will plan on replacing them in 12 to 18 months.

ion_pump_cf_flange

ion_pump_cf_flange

endoscope_inserted

endoscope_inserted

High_voltage_feedthru

High_voltage_feedthru

flakes_in_pump_well

flakes_in_pump_well

Pits_on_titanium_plate

Pits_on_titanium_plate

coating_on_ceramic

coating_on_ceramic

 

 

Calibrating the SIMSII RF Generator

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Calibrating the SIMSII RF Generator

This post shows you how to calibrate the Balzers QMH RF generators that are used on the PHI SIMSII and 6300/6600 series SIMS systems.

1. Load in a Molybdenum sample. Note that the sample mount covers on PHI sample mounts are made out of Molybdenum so if you have one of those on your sample you can use the cover.

2. Monitor the voltage on the two recessed banana jacks on the front of the RF generator with a DVM set to DC millivolts.

tuning_test_points

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.  In AugerScan set up a SIMS alignment with a Peak AMU of 10 and a range of zero.  Note that for this adjustment the ion beam does not need to be on.

sims_alignment_dialog_box

 

 

 

 

 

 

 

 

 

4. Acquire the alignment and adjust the Tuning capacitor on the back side of the RF generator for the minimum voltage.   The capacitor is a tuning type like what was used in old radios. The shaft of the capacitor is attached to a wheel with holes in it. To adjust the capacitor you put a small thin screwdriver or an Allen wrench into one of the holes and move the capacitor wheel left and right. There is a little bit of hysteresis in the adjustment so you will need to go back and forth a little bit to make sure that you are at the minimum voltage value.

The DC voltage will minimize at about 10 to 20mV depending on the RF generator AM range and the size of the quadrupole.

Once you have minimized the DC voltage stop the alignment. Change the AMU to 50 and repeat step 4.

5. Next change the AMU in the alignment to 200 AMU and adjust for minimum voltage. 200 AMU is as high as you will need to go as most of the RF generators only go up to a maximum of 250 AMU. But even if you have one that goes up to 500 or even 1000AMU, the effective signal above 200 AMU is minimal and so I think that it makes more sense to optimize the tuning over the effective range of the RF generator rather than the absolute maximum AMU.    The voltage at 200 amu will be about 400 to 600mV depending RF generator AMU range and the quad diameter.  The important thing is to minimize the voltage at 200 AMU.

After tuning the next step will be to adjust the peak positions.

6. The ion beam needs to be set up for normal operation and the raster turned OFF. Open the O2 leak valve on the SIMS II energy analyzer (top of SIMSII) and set it so that the vacuum in the chamber is 2 X 10-7 Torr. There is some hysteresis in the gas line so be very careful when adjusting this valve. My technique is to slowly open the valve and as soon as I see the pressure in the chamber starting to come up I close the valve ¼ turn and wait for the pressure to stabilize before further adjustment.

7. Set up an alignment in POS SIMS with an AMU of 16 and a range of 3. Set the time per step to 50ms.

sims_adjustment_pots

 8. Acquire the alignment and adjust the Cal LOW potentiometer on the RF generator so that the 16 AMU O2 peak is centered. Note that for this adjustment the ion beam needs to be on. CCW moves peak up.

9. Change the AMU to 98 and a range of 3.   Adjust the Cal HIGH potentiometer on the RF generator so that the 98 AMU moly peak is centered. The 98 Moly peak will be the highest peak in the group of peaks between 92 and 100 AMU.  CCW moves peak up.

10. Recheck the 16 AMU peak and readjust if necessary. If you adjust the 16 AMU peak then you will also need to adjust the 98 AMU peak as well.

Next we will adjust the resolution linearity. The resolution is adjusted by a combination of the Resolution number in the software and also the actual resolution fine potentiometer on the RF generator. We will adjust the resolution for what is called the 10% value. The 10% value represents the ratio between the 95 and 96 Moly peaks and when viewed in the log scale is one order of magnitude on the graph. We further will want to adjust the resolution linearity so that the peaks from 90 to 100 AMU and also 185 to 195 AMU on Moly are both showing approximately a 10% peak to valley ratio, as shown in the survey below.

10_percent_linearity

The resolution number in the software acts like a resolution offset – it affects the entire range of AMU. The resolution gain potentiometer on the RF generator acts like a gain, it has more effect on the high AMU than the low AMU. By selecting the correct Resolution number in the software and adjusting the resolution Fine potentiometer on the RF generator the overall resolution linearity can be adjusted.

11. Set up two survey windows in AugerScan. One will be set from 90 to 100 AMU and the other from 185 to 195 AMU. Initially set the resolution in the software to the last known good value or the value that is written on the front of the RF generator. Use an AMU of .05 and a time per step of 50 ms, one sweep.

10 percent moly peaks

 

 

 

12. Acquire both surveys (one at a time).

In each window the goal is to have approximately 10% peak to valley ratio (in the log scale). Adjust the resolution number for the 90 to 100 AMU peaks and the resolution fine for the 185 to 195 peaks. CW = more resolution. Remember that the Resolution number in the software will affect both the low and high peaks, and that the resolution fine pot on the RF generator will have more effect on the high peaks than the low peaks. Here is a table that might be helpful-

sims_adjustment_table

 Note that any time you change the resolution number for the 90 to 100 survey you need to change it to the same value for the 185 to 195 survey.

After a few iterations you will have the resolution set so that both the low and high AMUs are approximately 10% resolution.

13. Once the resolution linearity adjustment is complete, recheck the 16 AMU and 98 AMU peak positions and adjust if necessary.

If you run out of range on the resolution fine adjustment or the cal low peak position contact RBD Instruments for additional procedures on how to correct those issues.