{"id":2414,"date":"2008-03-24T10:58:43","date_gmt":"2008-03-24T10:58:43","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/2008\/03\/24\/lab-porn-plasma\/"},"modified":"2008-03-24T10:58:43","modified_gmt":"2008-03-24T10:58:43","slug":"lab-porn-plasma","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2008\/03\/24\/lab-porn-plasma\/","title":{"rendered":"Lab Porn: Plasma!"},"content":{"rendered":"

A couple more pretty pictures of the apparatus, to pass the time:<\/p>\n

\"i-6bbb9b4f578217a9a4256850f6a349ed-sm_discharge.jpg\"<\/p>\n

This is the plasma discharge source that we use to make metastable atoms. We excite the gas using a RF coil (under the tinfoil) with a couple of watts of power at 145 MHz (local ham radio people must love me…), which creates a discharge in the glass tube. Some small fraction of the atoms are excited to the state that we want in the chaos of the plasma, and we work with those downstream.<\/p>\n

When it’s working right, there’s a pretty steep pressure drop across the discharge region:<\/p>\n

<\/p>\n

\"i-fcd5a3ff131a5b25073dd1b40bd9eb69-sm_pressure_drop.jpg\"<\/p>\n

The pressure is much lower on the left (there’s a honkin’ big pump just out of the frame), which is why the color changes. Of course, if you screw up the valve settings, and let the pressure get too high all through the system, you get a kind of pretty effect:<\/p>\n

\"i-20b6f6cca643f12b0f014f3fbfc009a2-sm_discharge_chamber.jpg\"<\/p>\n

Here you can see the discharge extending into the source chamber, because there’s enough gas in there to keep it going. This is no good for the experiment, but it does look pretty cool.<\/p>\n

And that should be enough pretty pictures to keep people occupied until I get back…<\/p>\n","protected":false},"excerpt":{"rendered":"

A couple more pretty pictures of the apparatus, to pass the time: This is the plasma discharge source that we use to make metastable atoms. We excite the gas using a RF coil (under the tinfoil) with a couple of watts of power at 145 MHz (local ham radio people must love me…), which creates… Continue reading Lab Porn: Plasma!<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"1","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,32,7,50],"tags":[],"class_list":["post-2414","post","type-post","status-publish","format-standard","hentry","category-experiment","category-my_lab","category-physics","category-pictures","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/2414","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/comments?post=2414"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/2414\/revisions"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=2414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=2414"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=2414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}