Purdue University - High EnergyPhysics

CLEO III Silicon Group


People who contributed to Si3

Summary of Current Status of Production at Purdue

CLEO Si3 Meeting Minutes and Transparencies


Si3 Review Committee Document

Si3 Review Committee Document Draft 2

New: Live Action Video from the CLEO Experimental Hall

CLEO III Silicon Upgrade Photographs and Figures


404 Post


Si3 in the news

Various PR plots in postscript

Recent Talks


Other CLEO Web Pages
The Cornell CLEO Homepage

The CLEO III Upgrade-Cornell

Cornell - assorted CLEO pictures (by Chris Bebek)

Pablo Hopman's Silicon Pages

OSU Silicon group sites
Electronics and Hybrids

Status Reports

OU Silicon Group-Detector Testing and Flex Circuits

Wayne State University - CLEO III Interaction Region and Beam Pipe

Updated: December 17, 1999

The Si3 Group November 30, 1999 with the complete layer 3/4 assembly which contains (about 80% of the silicon). L-R Eric Reber (undergrad), Ian Shipsey (Professor), Steve Kane (undergrad), Kirk Arndt (Engineer), David Miller (Professor), Tom Smith (Technician), Jim Fast (Sr. Scientist), Jik Lee (Research Scientist).

Particle Physics for 7 year olds- Photographs of children who painted the shipping crate. Thank-you notes from the children. Journal & Courier article (which explains how the children came to be involved). Physics for 4 year olds - thank you notes, pictures. Hillcrest Elementary, Delphi, February 12, 2002 thank you notes and photos. Happy Hollow Elementary, West Lafayette, February 27, 2002 thank you notes.

Our latest picture of the silicon detector 11/27/99 is at: CLEO III Silicon Detector Outer Layers (warning this is a high resolution picture).

Pictures of the layer 1 and 2 assembly are at clamshell pictures.

The layer 3 and 4 subassembly journey from West Lafayette to Ithaca.

Why did we build a silicon detector?

The Origin of Matter:
At the beginning of the Universe all the energy and matter we see today was squeezed into a space much less than 1 millimeter across. This confinement produced a very dense state in which heavy subatomic particles could exist. When most subatomic particles decay they produce equal amounts of stable matter and anti-matter, which subsequently meet and annihilate producing energy in the form of light. Today's Universe has about 109 times as much light as matter, and no anti-matter. It is conjectured that when certain subatomic particles, such as the beauty quark, decay they do so producing slightly more matter than anti-matter, so that after annihilation a small amount of matter remains. Similar processes during the period 10-35 to 10-12 seconds after the birth of the Universe may have given rise to the matter that permits us to exist.

To test this hypothesis the Purdue CLEO group is part of a 22 university CLEO experiment which collides electrons with positrons to produce beauty quarks at the Cornell Electron Storage Ring. As part of an upgrade to the experiment the Purdue group is leading the construction of a silicon vertex detector (Si3) which is based on microelectronic technology similar to a video camera. Si3 is a very precise, accurate and fast array of 450,000 cameras that detects the birth and death of the beauty quark, whose existence lasts for a trillionth of a second. Si3 is the most advanced detector of its type ever constructed at a university.

Above: The 450,000 cameras, each 50 microns apart, are electrically connected to each other by tiny hair-like wires using a technique called wirebonding. In this picture forty wirebonds are visible. The dime sets the scale. For Si3 half a million wirebonds were made at Purdue.

Much more detail can be found in articles by John Ellis (CERN), Ian Shipsey (Purdue) and the Purdue Univeristy News Service.

This research is supported by the United States National Science Foundation NYI Young Investigator Award 9257444, The United States Department of Energy grant DE-FG02-91ER40681 The Department of Physics, Purdue University, the School of Science, Purdue University and Purdue University.