{"id":2071,"date":"2017-10-04T14:26:03","date_gmt":"2017-10-04T21:26:03","guid":{"rendered":"https:\/\/www.rbdinstruments.com\/blog\/?p=2071"},"modified":"2017-10-04T14:26:03","modified_gmt":"2017-10-04T21:26:03","slug":"homemade-titanium-sublimation-pump","status":"publish","type":"post","link":"https:\/\/www.rbdinstruments.com\/blog\/homemade-titanium-sublimation-pump\/","title":{"rendered":"Homemade Titanium Sublimation Pump"},"content":{"rendered":"

In this post I show how we made a small homemade titanium sublimation pump for an 8\u201d Kimball Physics spherical octagon UHV vacuum chamber.<\/p>\n

Our little chamber has a 60 l\/s ion pump, but even with baking (both IR and UVC), we were able to get only into the low 10-8 to high 10-9 Torr range.\u00a0 However, using the little titanium sublimation pump, which we \u201cFrankensteined\u201d together using parts we had readily available, allowed us to get in the low 10-9 to high 10-10 Torr range, a factor of ten improvement.<\/p>\n

A titanium sublimation pump works by heating a titanium filament wire to about 1300 degrees C. That is hot enough to create titanium gas molecules (sublimate) but not so hot that the filament wire melts.\u00a0 The sublimated titanium deposits on the wall of the chamber (or preferably on a shield wall) and forms a thin film. This layer of titanium is very reactive and will bond with other molecules in the vacuum chamber such as CO and O2. Disassociated hydrogen and water vapor also diffuse into the titanium layer.<\/p>\n

The reactivity of the titanium film is increased with lower temperatures, but most titanium sublimation pumps are operated at room temperature. Over time, the titanium film will become coated and need to be replenished. All commercial titanium sublimation pumps have 3 to 4 filaments so that when one filament burns out you can switch to another. Those filaments are also relatively thick in diameter at 12 gauge (.080\u201d) and need about 50 amps of current to operate.<\/p>\n

For our homemade titanium sublimation pump, we used 24 gauge (.020\u201d) so that we could operate at a much lower current of 4 amps.\u00a0 We also only have one filament.<\/p>\n

Before I show how we made our homemade titanium sublimation pump, here are links to some videos on how TSPs work:<\/p>\n

https:\/\/www.youtube.com\/watch?v=j5Y7m2ZJfgg<\/a><\/p>\n

https:\/\/www.youtube.com\/watch?v=9vJedaxRsxI<\/a><\/p>\n

The first thing that we needed was a 2-pin electrical feedthrough on a 2.75\u201d CF flange.\u00a0 For that we used a Getter pump flange from a PHI 04-303 ion gun as shown below.<\/p>\n

\"filament_wire_connections\"

We then needed to somehow support and electrically isolate the TSP filament wire. To do that we used a coupler and some little shoulder washers.<\/p>\n

\"Ceramic_support\"

The top part of the getter pump assembly is conveniently designed to allow gas molecules to pass through but also block direct deposition of titanium into the vacuum chamber.<\/p>\n

\"\"

Next we added a few turns into the titanium wire so that it would have a little bit of a spring to it. Then we connected the wire to the flange and support assembly. We have only one filament and so by effectively doubling the length of the wire we could also double the amount of titanium that we would be sublimating.<\/p>\n

\"filament_wire\"

For a chamber wall we used a 2.75\u201d nipple that has a tube ID of 1.6\u201d and a length of 4\u201d.\u00a0 The larger the surface area the better, but for the size chamber that we have, we are limited to a small 2.75\u201d nipple. We mounted this nipple on our chamber horizontally so that any flakes that form will not get into the chamber or ion pump.<\/p>\n

\"2.75_inch_CF_nipple\"

For a power supply, we used a 30 volt 5 amp Lavolta.<\/p>\n

\"30V_5amp_power_supply\"

After installing our homemade titanium sublimation pump into the chamber we pumped down and were ready to operate the TSP.<\/p>\n

To operate our titanium sublimation pump, we slowly increased the power supply current while observing the color of the light coming off the TSP filament and also monitoring the chamber pressure.\u00a0 The filament needs to be orange for the titanium to sublimate. Too hot and the lifetime of the filament will be reduced. Too low and the pumping effect is reduced. By experimenting we determined that about 3.8 amps DC was the correct amount of current.\u00a0 Once that was determined, we could just periodically turn the TSP on for about 2 minutes at a time.\u00a0 We did that 3 times over a 6-hour period and then let the chamber pump overnight. The next morning we were in the high 10-10 Torr range.\u00a0 Success!<\/p>\n

\"tsp_filament_in_operation\"

Conclusions:<\/p>\n

    \n
  1. It is possible to make a small titanium sublimation pump using off-the-shelf components that will operate with less than 5 amps of DC current.<\/li>\n
  2. Adding a titanium sublimation pump to a small chamber can help to get from HV to UHV.<\/li>\n<\/ol>\n

     <\/p>\n

     <\/p>\n

     <\/p>\n

     <\/p>\n","protected":false},"excerpt":{"rendered":"

    In this post I show how we made a small homemade titanium sublimation pump for an 8\u201d Kimball Physics spherical octagon UHV vacuum chamber. Our little chamber has a 60 l\/s ion pump, but even with baking (both IR and … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":2072,"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":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[164],"tags":[34],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2017\/10\/tsp_filament_in_operation.jpg?fit=586%2C486&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p2DEXo-xp","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":215,"url":"https:\/\/www.rbdinstruments.com\/blog\/titanium-sublimation-pump-operation\/","url_meta":{"origin":2071,"position":0},"title":"Titanium sublimation pump operation","author":"Randy","date":"November 18, 2012","format":false,"excerpt":"The TSP (titanium sublimation pump) is used in conjunction with an ion pump to improve pumping efficiency.\u00a0 It works by evaporating a titanium film onto the cryopanel or TSP shield. The titanium film is very reactive and so the gas molecules in the chamber that collide with the cryopanel wall\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":"TSP Filament orientation","src":"https:\/\/i0.wp.com\/rbdinstruments.com\/blog\/wp-content\/uploads\/2012\/11\/Filament-oreintation.png?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":1548,"url":"https:\/\/www.rbdinstruments.com\/blog\/up-to-air\/","url_meta":{"origin":2071,"position":1},"title":"660 System up to air procedure","author":"Randy","date":"August 5, 2015","format":false,"excerpt":"Overview This procedure will allow you to safely bring the 660 scanning auger system up to air for maintenance. \u00a0 Shut down AugerMap and turn off the 20-610 electron gun control (filament down slowly) Also turn off the 20-622 gun control. Turn off the card rack power If V4 is\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":"phi-660-scanning-auger","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2015\/08\/SAM660.jpg?fit=1200%2C900&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2015\/08\/SAM660.jpg?fit=1200%2C900&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2015\/08\/SAM660.jpg?fit=1200%2C900&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2015\/08\/SAM660.jpg?fit=1200%2C900&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":606,"url":"https:\/\/www.rbdinstruments.com\/blog\/tnbx-ion-pump\/","url_meta":{"origin":2071,"position":2},"title":"Servicing a P-E TNBX Ion Pump Well","author":"Joe Caterinicchio","date":"February 21, 2015","format":false,"excerpt":"RBD Instruments provides all of the parts that you need to rebuild these TNBX ion pump wells.\u00a0 Contact us for more information.\u00a0 For best results, read this entire post and then look at the pictures at the bottom of the post. 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The AVC provides control of the pneumatic valves on the system by using 24V DC solenoids to route air\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":"remove screw","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2019\/06\/remove-screw.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\/2019\/06\/remove-screw.jpg?fit=972%2C648&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2019\/06\/remove-screw.jpg?fit=972%2C648&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":2645,"url":"https:\/\/www.rbdinstruments.com\/blog\/infrared-bakeout-package\/","url_meta":{"origin":2071,"position":5},"title":"Infrared Bakeout Package","author":"Randy","date":"November 14, 2019","format":false,"excerpt":"Our new VB series bakeout packages are an easy way to remove water vapor from vacuum chambers. 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The BC-3 controller uses thermocouple feedback to regulate the vacuum chamber temperature, controls the power to the IRB-600\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":"BC-3-Bake-Out-Controller","src":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2019\/11\/BC-3-Bake-Out-Controller.jpg?fit=938%2C500&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2019\/11\/BC-3-Bake-Out-Controller.jpg?fit=938%2C500&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.rbdinstruments.com\/blog\/wp-content\/uploads\/2019\/11\/BC-3-Bake-Out-Controller.jpg?fit=938%2C500&ssl=1&resize=700%2C400 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/2071"}],"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=2071"}],"version-history":[{"count":2,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/2071\/revisions"}],"predecessor-version":[{"id":2086,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/posts\/2071\/revisions\/2086"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/media\/2072"}],"wp:attachment":[{"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/media?parent=2071"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/categories?post=2071"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rbdinstruments.com\/blog\/wp-json\/wp\/v2\/tags?post=2071"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}