{"id":359,"date":"2013-02-17T10:07:24","date_gmt":"2013-02-17T18:07:24","guid":{"rendered":"http:\/\/www.rbdinstruments.com\/blog\/?p=359"},"modified":"2014-11-06T09:02:19","modified_gmt":"2014-11-06T17:02:19","slug":"lab6-filament-rejuvenation","status":"publish","type":"post","link":"https:\/\/www.rbdinstruments.com\/blog\/lab6-filament-rejuvenation\/","title":{"rendered":"LaB6 filament Rejuvenation"},"content":{"rendered":"

Lanthanum hexaboride (LaB6 <\/sub>) filaments provide a very stable emission of electron current in the hot cathode electron sources used in many scanning Auger electron spectrometers. However, this type of filament is susceptible to deactivation from vacuum contaminants such as fluorine.<\/p>\n

If your LaB6 <\/sub>filament becomes contaminated it may exhibit symptoms such as unstable emission current or no emission current at all.\u00a0 The Auger data below shows instability in the background that was caused by unstable emission current from the cathode.<\/p>\n

\"Unstable

Usually it is possible to rejuvenate a LaB6<\/sub> filament by backfilling the chamber with Oxygen while monitoring the emission current as outlined in the procedure below.<\/p>\n

LaB6<\/sub> filament: rejuvenation procedure:<\/p>\n

    \n
  1. Set the beam voltage to 1kV and the emission voltage to 100% (or the maximum for that beam voltage).<\/li>\n
  2. Increase the filament current up to the normal operating value. 1.3 to 1.5 amps is typical for a PHI 600 or 660 scanning auger spectrometer.<\/li>\n
  3. Bleed O2<\/sub> into the system to about 5 X 10 -7<\/sup> Torr.<\/li>\n
  4. Slowly reduce the emission voltage until you get about 50uA of emission current.\u00a0 Keep an eye on it, as the O2<\/sub> cleans the filament the emission will rise and you will need to increase the emission voltage in order to keep the emission current from going up too much. The maximum recommended emission current is 100uA.<\/li>\n<\/ol>\n

    Once the emission current is stable then you can turn off the O2<\/sub>. This process typically takes 5 to 20 minutes. In some cases the vacuum chamber may have some low level contamination where the emission current of the filament will drop once the O2<\/sub> is turned off. In those cases, you may want to leave the O2 on for an extended period of time at a higher vacuum such as 2 X10-8<\/sup> Torr.<\/p>\n

    If rejuvenating the filament does not work then the filament may need to be replaced. RBD Instruments Inc. provides LaB6<\/sub> filaments for the Physical Electronics PHI 590 through 660 series scanning auger spectrometers. \u00a0Visit\u00a0 us at rbdinstruments dot com<\/p>\n","protected":false},"excerpt":{"rendered":"

    Lanthanum hexaboride (LaB6 ) filaments provide a very stable emission of electron current in the hot cathode electron sources used in many scanning Auger electron spectrometers. However, this type of filament is susceptible to deactivation from vacuum contaminants such as … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":361,"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":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[162],"tags":[53,54],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2013\/02\/bad-590-lab6-no-emmsion.jpg?fit=320%2C240&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p2DEXo-5N","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":677,"url":"https:\/\/www.rbdinstruments.com\/blog\/lab6-filament-replacement-procedure\/","url_meta":{"origin":359,"position":0},"title":"Lab6 filament replacement procedure","author":"Randy","date":"July 9, 2013","format":false,"excerpt":"This procedure shows the steps to replace the Lab6 filament in the 25-120A CMA used in the Physical Electronics 600 and 660 scanning auger systems. First, vent the system. Here is a link to a procedure on how to do that: 600_System_Up-to-air_Procedure Remove the filament cap on the top of\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":"tilt back filament housing","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2013\/07\/tilt-filament-housing-back-on-hinge.jpg?fit=588%2C330&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":1349,"url":"https:\/\/www.rbdinstruments.com\/blog\/25-110-analyzer-filament\/","url_meta":{"origin":359,"position":1},"title":"25-110 Analyzer Filament","author":"Randy","date":"February 11, 2015","format":false,"excerpt":"This is an old tech tip that I wrote back in 2002. The 25-110 analyzer was the first CMA that Physical Electronics used a Lab6 filament in. These days there are not a lot of 590 systems still in operation, but the ones that are still work well especially as\u2026","rel":"","context":"In "General Optics and Vacuum"","block_context":{"text":"General Optics and Vacuum","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/general-optics-and-vacuum\/"},"img":{"alt_text":"Loosen-bottom-cap-set-screws","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2015\/02\/Loosen-bottom-cap-set-screws.jpg?fit=640%2C480&ssl=1&resize=350%2C200","width":350,"height":200},"classes":[]},{"id":54,"url":"https:\/\/www.rbdinstruments.com\/blog\/imaging-on-a-scanning-auger-electron-microprobe\/","url_meta":{"origin":359,"position":2},"title":"Imaging on a PHI scanning auger electron microprobe","author":"Randy","date":"August 20, 2012","format":false,"excerpt":"This topic is something that we still get regular requests for information about. I first wrote this tech tip back in 2004 to summarize the training that we perform when installing a PHI 660 scanning auger electron microprobe.\u00a0 It still comes in handy today, especially in university labs where the\u2026","rel":"","context":"In "Theory"","block_context":{"text":"Theory","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/theory\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1205,"url":"https:\/\/www.rbdinstruments.com\/blog\/11-010-electron-gun-control-operation-repair-info\/","url_meta":{"origin":359,"position":3},"title":"11-010 electron gun control operation and repair info","author":"Randy","date":"August 9, 2014","format":false,"excerpt":"This post is a compilation of information that we have provided in some of our newsletters about the Physical Electronics 11-010 electron gun control. These units are typically found with the 10-150\/155 and 15-255G CMA auger and double pass x-ray photoelectron analyzers. As always, refer servicing to personnel trained to\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":"","src":"","width":0,"height":0},"classes":[]},{"id":3106,"url":"https:\/\/www.rbdinstruments.com\/blog\/cmapp-new-features\/","url_meta":{"origin":359,"position":4},"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":707,"url":"https:\/\/www.rbdinstruments.com\/blog\/10-155-filament-replacement-procedure\/","url_meta":{"origin":359,"position":5},"title":"10-155 Filament replacement procedure","author":"Randy","date":"July 22, 2013","format":false,"excerpt":"This blog post is an updated version of the 10-155 filament replacement procedure first published on the RBD Instruments website as a Technical Tip a number of years ago. This version has been updated with some close up pictures of the electron gun assembly shown at the bottom of this\u2026","rel":"","context":"In "General Optics and Vacuum"","block_context":{"text":"General Optics and Vacuum","link":"https:\/\/www.rbdinstruments.com\/blog\/category\/general-optics-and-vacuum\/"},"img":{"alt_text":"filament-coupler-space-between","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2013\/07\/filament-coupler-space.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\/2013\/07\/filament-coupler-space.jpg?fit=972%2C648&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2013\/07\/filament-coupler-space.jpg?fit=972%2C648&ssl=1&resize=700%2C400 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/359"}],"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=359"}],"version-history":[{"count":1,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/359\/revisions"}],"predecessor-version":[{"id":362,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/359\/revisions\/362"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/media\/361"}],"wp:attachment":[{"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/media?parent=359"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/categories?post=359"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/tags?post=359"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}