{"id":38,"date":"2008-09-11T12:58:05","date_gmt":"2008-09-11T17:58:05","guid":{"rendered":"http:\/\/blog.richmond.edu\/physicstrawick\/2008\/09\/11\/the-lhc-the-worlds-purest-diamond-and-my-50-micron-contribution-to-a-17-mile-tunnel\/"},"modified":"2008-09-11T13:12:22","modified_gmt":"2008-09-11T18:12:22","slug":"the-lhc-the-worlds-purest-diamond-and-my-50-micron-contribution-to-a-17-mile-tunnel","status":"publish","type":"post","link":"https:\/\/blog.richmond.edu\/physicstrawick\/2008\/09\/11\/the-lhc-the-worlds-purest-diamond-and-my-50-micron-contribution-to-a-17-mile-tunnel\/","title":{"rendered":"The LHC: the world’s purest diamond and my 50 micron contribution to a 17 mile tunnel"},"content":{"rendered":"

With the recent news of the successful startup of the large hadron collider (LHC)<\/a> at CERN, I’m reminded that I actually worked on a small piece of it back in the late 1990s, in one of my former lives as a graduate student at Ohio State University.\u00a0 The LHC is the new, big, expensive, high energy particle accelerator, a 17 mile long tunnel that will accelerate particles to very high speeds, ultimately making collisions which will\u00a0 mimic the conditions of the early universe just after the big bang.\u00a0<\/p>\n

My own tiny piece of the project involved making tracking devices to detect the particles ejected from these high energy collisions. These tracking devices consist of a thin slab of insulating or semiconducting material, with a grid of tiny metal wires running horizontally on one side and vertically on the other.\u00a0 When a high energy particle comes tearing through, it ionizes atoms in the material, creating small voltages on the nearby wires.\u00a0 By monitoring the voltages on all of the wires, scientists can measure the precise x-y location of the high energy particle.\u00a0 The actual detector at the end of the 17 mile long tunnel consists of many thousands of these devices, arranged in a sphere surrounding the area where the collision occurs.\u00a0 By accurately tracking all of the particles ejected from a collision, scientists can work backwards to understand the physics of the collision itself.<\/p>\n

In an accelerator as powerful as the large hadron collider, the spray of ejected particles would basically shred ordinary tracking devices, which are normally made of silicon.\u00a0 I worked briefly with the RD42 collaboration to help develop tracking devices made of diamond, which is much less susceptible to radiation damage.\u00a0 As part of the project, the group helped develop very high purity synthetic diamonds made by a chemical vapor deposition (CVD)<\/a> technique.\u00a0 The chemical and electrical purity of these diamonds easily surpasses that of any naturally occurring diamond on the earth, and at one point I actually held in my hand what at the time was the most perfect diamond the world had ever seen.\u00a0 (It looked like a small piece of glass, about a centimeter square, maybe a couple of millimeters thick.)\u00a0<\/p>\n

I helped the group to perform the lithography<\/a> required to pattern\u00a0the diamond’s\u00a0surfaces with a dense array of 50 micron gold wires, about the thickness of a human hair.\u00a0 (It was a fairly standard application of existing lithography technology, made only slightly trickier by the roughness and optical properties of the diamond surface.)\u00a0 Interestingly, I never set out to be a high energy physicist, and initially I didn’t have anything to do with the group working on the LHC at Ohio State University.\u00a0 At the time, I was actually using lithography to attach electrodes to tiny superconducting crystals for a completely unrelated experiment; I just\u00a0happened to be the local expert there when the LHC group needed some help to prepare for some upcoming “beam time” at another accelerator.\u00a0 I took time away from my normal Ph.D. work to help them out, and it ended up being a very interesting and ultimately successful collaboration.<\/p>\n

The moral of the story, for those of you who like that sort of thing, is to pay attention to what your colleagues are working on, even if it seems unrelated to what you’re doing.\u00a0 There may be connections to your own work that aren’t so obvious.\u00a0 The LHC is a huge project, and many thousands of people have contributed to it; I sometimes wonder how many of those are\u00a0accidental contributors like me.\u00a0 Accidental or not, I’m proud to have played even a tiny technical part in the experiment, and I look forward to the new physics it will tell us.<\/p>\n","protected":false},"excerpt":{"rendered":"

With the recent news of the successful startup of the large hadron collider (LHC) at CERN, I’m reminded that I actually worked on a small piece of it back in the late 1990s, in one of my former lives as a graduate student at Ohio State University.\u00a0 The LHC is the new, big, expensive, high … Continue reading The LHC: the world’s purest diamond and my 50 micron contribution to a 17 mile tunnel<\/span><\/a><\/p>\n","protected":false},"author":21,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[508],"tags":[],"class_list":["post-38","post","type-post","status-publish","format-standard","hentry","category-research"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/posts\/38","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/users\/21"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/comments?post=38"}],"version-history":[{"count":0,"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/posts\/38\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/media?parent=38"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/categories?post=38"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.richmond.edu\/physicstrawick\/wp-json\/wp\/v2\/tags?post=38"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}