Historical Content Note: The following material is reprinted from publications from throughout Fermilab's history. It should be read in its original historical context.

D0 Takes First Data

This spring heralded the arrival of Fermilab's most modern collider detector, the D0 detector. After much hard work and successful testing by D0 physicists and staff, the detector began operation in May.

The completion and commissioning of the D0 detector involved years of working under a tight schedule, said Paul Grannis, guest scientist in the D0 Department and spokesman for the project.

After the final assembly and installation of the many detector parts was finished in the summer of 1991, the detector underwent a series of lengthy tests. In February of 1992, the detector was pushed from the Assembly Hall to the Collision Hall where it was then aligned and positioned on the beam line and hooked up. "A lot of hard work went in to starting up the experiment," said Jim Christenson of the D0 Department. "We had to make sure the entire apparatus worked properly on the Tevatron beam line in the Collision Hall."

By the middle of March, the detector was in place and tests were begun using cosmic rays. On the morning of May 12, the detector saw its first collision.

According to Paul, all major parts of the detector are working well and they have begun looking at their first events. "The total number of events is small compared to the amount in the total run," Paul said. "We expected to receive 25 inverse picobarns of data in the full run, but so far we have had only about lOOOth of the that total."

As time goes by, Jim said, D0 will see more collisions. "Right now, the accelerator is still in the commissioning mode and we are attempting to set up the detector to select interesting collisions properly."

The accelerator is scheduled to be shut down for a two-week period starting July 20. Once it is running again in August, D0 should be in the position to see some interesting events, Jim said. Right now, D0 is getting preliminary data to calibrate the detector and the electonics with little in the way of publishable physics, he added.

In this run, D0 hopes to find the top quark, which Paul said is possible if the mass of the top quark proves not to be too high. D0 will also be making precision studies of the W and Z bosons and testing the electroweak sector of the Standard Model. Searching for new supersymetric particles and conducting a large variety of precision tests of QCD are also on D0's agenda.