20-805 or 11-500A analyzer control sweep voltage test

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Older PHI cylindrical mirror analyzers (CMA) uses two cylinders to focus electrons of a particular energy into an aperture for amplification via an electron multiplier.

For AES, the inner cylinder is at ground potential and the outer cylinder has a voltage applied to it (sweep voltage) that deflects the electrons into the collection aperture .

This blog post will show you how to test the sweep voltage.

11-500A Analyzer Controller

Turn off the 11-500A analyzer controller.

Remove the VM cable from the analyzer.

Set up an alignment with the lower limit at 100eV and the upper limit also set to 100eV. This will set the sweep voltage to sit at 100eV.

Remove the VM cable from the analyzer.

Connect your DVM meter to the center pin on the end of the VM cable with respect to the vacuum chamber.

Turn on the 11-500A and measure the DC voltage on the end of the VM cable.

Acquire the alignment. The scale factor for the analyzer is 1.7 so the sweep voltage for 100eV is 100 divided by equals 58.823 VDC. If you have close to 58.8V DC on the end of the VM cable, then the 11-500A sweep voltage is working properly.

20-805 Analyzer Controller

15-255G Analyzer

Turn off the 20-805 analyzer controller. Make sure that it is in the AES mode.

Remove the OC cable from the analyzer.

Set up an alignment with the lower limit at 100eV and the upper limit also set to 100eV. 

Turn on the 20-805 and acquire the alignment. Measure the DC voltage on the end of the OC cable with respect to the vacuum chamber.  You should have about 58.5V DC on the end of the OC cable.  If so, then the sweep voltage is working properly.

25-260/270 Analyzer

Turn off the 20-805 analyzer controller. Make sure that it is in the AES mode.

Remove the Analyzer cable from the CMA.

Pin B on the analyzer connector is the OC voltage.

Sweep voltage test for PHI AES CMAs

Set up an alignment with the lower limit at 100eV and the upper limit also set to 100eV. 

Turn on the 20-805 and acquire the alignment. Measure the DC voltage on pin B of the OC cable with respect to the vacuum chamber.  You should have about 58.5V DC on the end of the OC cable.  If so, then the sweep voltage is working properly

If the sweep voltage is not working then contact RBD Instruments for assistance.

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