Acquire a depth profile region over a wide energy range but do not turn on the sputter ion gun.<\/li><\/ol>\n\n\n\nMethod 1 \u2013 Plot the target current vs. time.<\/h2>\n\n\n\n As shown in the pictures below, plotting the target current versus time shows the stability of the electron beam as well as trends in the current. In this case the current being measured is an electron beam in the range of approximately 300nA.<\/p>\n\n\n\nBy changing the scale of the plot, you can see finer details of the current stability and any trend. In this measurement the current drifted up by about 30 nA over a 2 hour period and started to stabilize after the first hour. Room temperature changes can effect the stability of electron optics as can thermal mass of the electron source.<\/p>\n\n\n\nMeasuring target current vs. time works well for electron beams on Auger spectrometers and SEMs, as well as secondary electrons generated by X-ray sources on XPS systems. \u00a0The secondary electron current generated by X-ray sources is directly proportional to the X-ray flux. <\/p>\n\n\n\n
Method 2 \u2013 Wide energy range depth profile.<\/h2>\n\n\n\n For this method you want to set up a region for a depth profile that is at least 1000 eV wide.\u00a0 In the example below we acquired from 1000 to 0 eV on a silver sample, 2 sweeps per cycle. Normally the ion gun is turned on for a depth profile but for this test the ion gun is not turned on. <\/p>\n\n\n\nIn the picture below you can see the Profile vs. time display\nwhere the highest count in each cycle is displayed. <\/p>\n\n\n\nThis picture of all 95 Ag cycles super imposed shows that the stability is pretty good.\u00a0\u00a0 A depth profile test like this tests not only the X-ray source stability, but also the analyzer voltages, electron multiplier and detector electronics. You can do the same test with an AES system which would test the electron gun as well as the analyzer,electron multiplier and detector electronics. <\/p>\n\n\n\nThis picture below shows the first cycle and the next picture shows the last cycle. If you look very closely you will see a small increase in the carbon peak that coincides with the over all slight drop in the intensity of the Ag profile vs. time display. Carbon will typically increase over time in UHV systems due to adsorption and desorption effects.<\/p>\n\n\n\nIf you have some extra time you may want to run one of these test methods on your XPS, AES or SEM. The results can be interesting and if nothing else will let you know that your system is stable. <\/p>\n","protected":false},"excerpt":{"rendered":"
There are two easy ways to check the stability of the electron or photon source on an X-ray photoelectron spectrometer, Auger electron spectrometer or Scanning Electron microscope: Measure the target current and plot the results vs. time using a data … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","footnotes":"","jetpack_publicize_message":"Stability testing of surface analysis optics. This blog post shows two ways that you can measure the stability of your XPS, AES or SEM system vs. time.","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[164],"tags":[297,295,296],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2DEXo-Ij","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":3106,"url":"https:\/\/www.rbdinstruments.com\/blog\/cmapp-new-features\/","url_meta":{"origin":2747,"position":0},"title":"CMapp New Features","author":"Randy","date":"January 26, 2021","format":false,"excerpt":"A list of new features in CMapp, the RBD Instruments' microCMA data acquisition and data massage software.","rel":"","context":"In "microCMA"","block_context":{"text":"microCMA","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/microcma\/"},"img":{"alt_text":"estimate target current","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2021\/01\/target-current-9103-or-estimate.jpg?fit=364%2C566&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":371,"url":"https:\/\/www.rbdinstruments.com\/blog\/faraday-cup-procedure-to-align-ion-beam-current\/","url_meta":{"origin":2747,"position":1},"title":"Faraday cup procedure to align ion beam current","author":"Randy","date":"March 11, 2013","format":false,"excerpt":"Using Ta2O5 or SiO2 works well for aligning an ion beam to the focal point of an X-ray photoelectron or scanning Auger electron spectrometer. But, in order to optimize the ion beam focus at larger beam sizes, a Faraday cup is required. The Faraday cup used on many Physical Electronics\/PHI\u2026","rel":"","context":"In "Ion Sources"","block_context":{"text":"Ion Sources","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/ion-sources\/"},"img":{"alt_text":"faraday cup","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2013\/03\/faraday-cup-254x300.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":1600,"url":"https:\/\/www.rbdinstruments.com\/blog\/measure-electron-current-accurately\/","url_meta":{"origin":2747,"position":2},"title":"Measure electron current accurately","author":"Randy","date":"December 12, 2015","format":false,"excerpt":"To measure electron current accurately (or ion current) you need to take secondary electrons out of the measurement. This is easy to do if you have a Faraday cup. The Faraday cup traps secondary electrons which results in an accurate beam current measurement. If secondary electrons are allowed to leave\u2026","rel":"","context":"In "Operation and Calibration Procedures"","block_context":{"text":"Operation and Calibration Procedures","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/operation-and-calibration-procedures\/"},"img":{"alt_text":"Secondary electron cutoff","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2015\/12\/Secondary-electron-cutoff.jpg?fit=899%2C574&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2015\/12\/Secondary-electron-cutoff.jpg?fit=899%2C574&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2015\/12\/Secondary-electron-cutoff.jpg?fit=899%2C574&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2335,"url":"https:\/\/www.rbdinstruments.com\/blog\/how-to-test-the-bias-batteries-in-a-9103-picoammeter\/","url_meta":{"origin":2747,"position":3},"title":"How to test the bias batteries in a 9103 picoammeter","author":"Randy","date":"April 17, 2018","format":false,"excerpt":"The 9103 USB picoammeter is often equipped with a +90 V bias option which improves the accuracy of electron and ion current measurements (by reducing the number of low energy secondary electrons that are generated by the beam from leaving the target). The +90 V bias comprises two 45V batteries\u2026","rel":"","context":"In "9103 USB Picoammeter"","block_context":{"text":"9103 USB Picoammeter","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/9103-usb-picoammeter\/"},"img":{"alt_text":"9103 bias batteries","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2018\/04\/9103-Batteries.jpg?fit=972%2C648&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2018\/04\/9103-Batteries.jpg?fit=972%2C648&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2018\/04\/9103-Batteries.jpg?fit=972%2C648&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2261,"url":"https:\/\/www.rbdinstruments.com\/blog\/new-feature-use-the-9103-picoammeter-to-automatically-read-microcma-target-current\/","url_meta":{"origin":2747,"position":4},"title":"New Feature: Use the 9103 Picoammeter to Automatically Read microCMA Target Current","author":"Joe Caterinicchio","date":"March 29, 2018","format":false,"excerpt":"The latest software releases of Actuel for the 9103 Picoammeter and CMapp for the microCMA now support the ability to automatically read target current when acquiring data. To use this feature, you must (of course) have a 9103 Picoammeter running RBD's Actuel software. Run CMapp for the microCMA, select Hardware\u2026","rel":"","context":"In "9103 USB Picoammeter"","block_context":{"text":"9103 USB Picoammeter","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/9103-usb-picoammeter\/"},"img":{"alt_text":"microcma-hardware-properties","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2018\/03\/microcma-hardware-properties.png?fit=781%2C1025&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2018\/03\/microcma-hardware-properties.png?fit=781%2C1025&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2018\/03\/microcma-hardware-properties.png?fit=781%2C1025&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":1855,"url":"https:\/\/www.rbdinstruments.com\/blog\/9103-picoammeter-bias-modes\/","url_meta":{"origin":2747,"position":5},"title":"9103 Picoammeter bias modes","author":"Randy","date":"December 20, 2016","format":false,"excerpt":"9103 Picoammeter bias modes This post explains the 9103 picoammeter bias modes and also explains the concept of \u201cfloating\u201d. There are 4 picoammeter bias modes: No bias \u2013 the current source is connected directly to the picoammeter input Internal \u2013 a low noise DC supply (two 45 V DC batteries\u2026","rel":"","context":"In "9103 USB Picoammeter"","block_context":{"text":"9103 USB Picoammeter","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/9103-usb-picoammeter\/"},"img":{"alt_text":"Floating-the-9103-Functionality 5000V","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2016\/12\/Floating-the-9103-Functionality-5000V.png?fit=766%2C824&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2016\/12\/Floating-the-9103-Functionality-5000V.png?fit=766%2C824&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2016\/12\/Floating-the-9103-Functionality-5000V.png?fit=766%2C824&ssl=1&resize=700%2C400 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/2747"}],"collection":[{"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/comments?post=2747"}],"version-history":[{"count":2,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/2747\/revisions"}],"predecessor-version":[{"id":2761,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/2747\/revisions\/2761"}],"wp:attachment":[{"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/media?parent=2747"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/categories?post=2747"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/tags?post=2747"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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