Kamran Vaziri and Don Cossairt
June is the last month of Mike Witherell as the Fermi National Accelerator Lab (Fermilab) Director. Pierre Oddone is the new director of the Fermilab. During Witherell's time the colliding beams luminosity of the Tevatron dramatically improved. The latest record of 122E30/cm2/sec was achieved in April. On May 23, CDF and DZero announced the achievement of one inverse femtobarn of integrated luminosity. Concurrent with these increased levels of proton beam intensities and luminosities, radiation exposures, both individual and collective, continue to be at levels typical of recent years.
Fermilab's other two major experiments, MINOS and MiniBooNE, have been making good progress. The MINOS experiment has been taking beam. In mid-March, the first neutrino events at the far detector in conjunction with the beam started to show up. The first find was a neutrino-induced muon entering the detector. In its first full month, MINOS has run near its anticipated intensity and near its design repetition rate. Neutrinos are now being routinely detected at both the near and far detectors. However, a cooling water leak was found in the graphite target vacuum can, so the NuMI beam was inactive for two weeks while the experimenters were draining the water and trying to decide on how to proceed. A new target will be ready in July. For now the cooling water leak will be held back by pressurizing the target case with helium gas. Several parameters of this kludgy fix are being closely monitored. So far this temporary solution seems to be working and the beam intensity has been slowly raised to very close to design intensity.
On April 3, Fermilab passed an important milestone in the neutrino program. The total number of protons delivered to the MiniBooNE target over its two and a half years of operation reached 5E20. The Booster Neutrino Beam continues to operate well and will deliver many more protons by the time of the fall shutdown. Important physics results are expected from MiniBooNE late this year, using the data sample collected up to this year's shutdown. In addition to the 5E20 accomplishment, MiniBooNE will soon have other reasons to celebrate, having now recorded over a half-million neutrino events. Vernon Cupps of the Radiation Protection Group is aiding the MiniBooNE experiment by providing a foil-activation measurement to determine the "absolute" number of protons delivered to their pion production target. An announcement on the collaboration's search for sterile neutrinos is expected to be made in the fall.
