RunII Status and Prospects

by Michael Witherell

In mid-August, just a few weeks from now, CDF and DZero experimenters will present the first full round of Run II physics results at the Lepton-Photon Symposium at Fermilab. So far in Run II, we have delivered nearly twice the integrated luminosity of Run I, extending the physics reach of the experiments. Nonetheless, at this point, despite the very hard work and dedication of many talented people, the luminosity delivered to CDF and DZero has fallen below our initial plans and predictions for Run II.

IMPROVING RELIABILITY AND QUALITY

To maximize the Tevatron luminosity and hence the scientific potential of Run II, earlier this month Fermilab completed an accelerator plan for Run II through mid-2009. It will be reviewed by a Department of Energy panel on July 21-23. This is a good time to summarize where we are and where we are going with Run II at the Fermilab Tevatron.

At the start of FY2003, we estimated that the integrated luminosity for the year, that is, the total number of particle collisions delivered to the detectors, would reach a level between 200 and 320 inverse picobarns (pb^-1). We set a performance goal at 225 pb^-1. Meeting our performance goal by the August 25 start of the summer shutdown requires an average of 6.3 pb^-1 per week in integrated luminosity. We are working very hard to achieve this goal, but it will be a challenge. Over the course of the year, some weeks of operation were lost due to unscheduled shutdowns for various reasons, such as magnet failures and power pole replacement. In a record week in May, the accelerators delivered initial peak luminosities as high as 4.5 x 10³¹ cm^-2 sec^-1, but the peak luminosity has been well off the record for many of the accelerator stores. All of these factors have limited the integrated luminosity.

We can and we will improve the reliability and quality of accelerator operations. I am making changes in our organization to focus effort more effectively on improving the luminosity delivered every week, to quickly identify and remove limitations to increasing the luminosity, and to react faster to operational problems that develop. Starting immediately the Associate Director of Accelerators will hold a daily morning meeting with the Beams Division Head, the Head of Operations, the Run Coordinator, and the heads of the accelerator systems departments. They will assess the previous day's performance and react immediately to optimize the next day's performance. I will announce other changes as they are put in place. I will also call in additional effort from the entire laboratory to improve accelerator performance.

THE NEAR FUTURE

To optimize the scientific results in the next two years, we need to increase the data samples of the two collider experiments as much as possible. Between now and early 2005, we will:

• make continuous operational improvements designed to increase the efficiencies for proton and antiproton beam transfers;
  
  
• attack a series of maintenance projects to improve reliability of operations;
  
  
• upgrade instrumentation throughout the accelerator complex;
  
  
• improve alignment of accelerator components;
  
  
• upgrade the Antiproton Source to increase antiproton production rate;
  complete new damper systems in the Main Injector and Tevatron;
  
  
• optimize the orbits of beams in the Tevatron;
  
  
• commission the Recycler Ring; and
  
  
• introduce slip-stacking, a new technique that will increase Main Injector beam intensity for antiproton production.

THE LONGER FUTURE

The longer-term goal is to maximize the opportunity for discovery throughout the period of Run II. The Beams Division has completed a new long-term luminosity upgrade plan based on bottoms-up numbers. It presents parameters supported by computer modeling of the Tevatron and the antiproton cooling and accumulation systems. The experience acquired during two years of operation has given us a better understanding of the accelerators, allowing us to benchmark the model we are now using as a planning tool. We are also better able to estimate the number of hours of accelerator operation we can normally expect to achieve each week. The resulting targets for Tevatron luminosity are lower than our previous estimates; they are also more realistic.

The luminosity estimates presented for the period beyond FY2005 assume successful integration of the Recycler with electron cooling. The R&D program for electron cooling is progressing well. However, at this point we do not yet have a good enough understanding of the Recycler to present a completely worked-out plan for its commissioning. By next winter, using knowledge gained during the summer shutdown, we will be in a position to update our plan with new information.

At their June meeting, the Fermilab Physics Advisory Committee reviewed the status of upgrades to the CDF and DZero detectors in the light of the new accelerator plan. They conducted thoughtful and detailed discussions of this issue. They advised that I consult with the detector collaborations and with accelerator experts in reaching a decision on the scope of the detector upgrade projects. Of course, I will also consider |the results of the upcoming DOE review. Our goal remains the optimization of the potential for scientific discovery in Run II.

FOCUS AND DEDICATION

The physics program of the CDF and DZero experiments at the Tevatron collider represents the most important physics program now operating in particle physics. It is critical to the scientific success of the Tevatron Collider Run II and to the future of our laboratory that we deliver as much luminosity as possible to the detectors next year and every year after that. This will require an additional increase in the level of effort on the accelerator complex. It will require focusing that effort toward improved reliability and higher luminosity. Most important, it will require that all of us at Fermilab pull together to reach our goal.