D0

The mission of Fermilab is to provide the facilities to understand fundamental physics at the shortest distance scales. To explore forces at short distances very high energy collisions are typically required. The D0 experimental apparatus is used to observe the particles and clusters of energy that emerge from proton/anti-proton collisions. These head-on collisions provide maximal energy (about 2000 times the mass of the proton) where one can sift through the data recorded from various pieces of the detector in the search for states (particles or aggregations of particles) that can signal new physics.

The requirements for the D0 detector are: good geometrical coverage (surround the proton-antiproton collision point with detectors), precisely measure the energy and momentum of the outgoing particles (this is done with tracking chambers and calorimeters using highly segmented sections - about 50,000 in all), and identify the electrons, muons and jets (jets are the manifestation of the fractionally charged quarks which combine with one another to make the strongly interacting particles). In addition the detector must be fast, very fast. It has to look at 300,000 collisions per second and decide whether to save the detector data for further analysis. This sorting process is necessary for two reasons: there are insufficient resources to save and analyze data from every collision and not all collisions are interesting. We look for data that will provide evidence that there is something new or that answers a question posed by previous observations or present theories.

The detector was built during the years 1986 to 1992 at a cost of $70M. It is massive, 5000 tons, due to the requirement that the collision products be well measured. The collaboration of scientists, engineers and technicians that built and operate the detector number about 500 and they come from 50 institutes and universities around the world. A picture of the physicists who attended a recent collaboration meeting is shown here with a drawing of the detector (click on the detector image for a larger view).

If you come to the Fermilab Open House on September 13th you can participate in a tour of the D0 Assembly Hall where the D0 detector is undergoing modifications for an extended run in late 1999 or early 2000.