Since June, the installation of the major components of the 8-GeV extracted proton beamline have been installed, the passive shielding has been put into place, and the radiation monitoring instrumentation has been installed. The prompt radiation fields will be monitored using standard Fermilab "chipmunk" ion chambers in the conventional manner. However, this particular experiment will handle a beam of sufficient intensity to require confirmatory monitoring (a term with a specific U.S. regulatory meaning) of the releases of airborne radioactivity. Based upon experience of recent years, to improve the accuracy of the sampling of these effluents some improvements in the instrumentation was necessary. Until now it has always been possible to house most of the apparatus indoors. Under the conditions of MiniBooNE, this is not readily feasible. Thus, provisions for insulation against rapid temperature and humidity changes that occur in northern Illinois were needed. Also, due to industrial hygiene concerns, it was prudent to eliminate the use of lead for gamma-ray shielding.
One of these new stack monitors is pictured below as installed and ready for use.
In the first picture, one sees the apparatus installed in a conventional ice chest.
The second picture shows the apparatus as housed in a shed adjacent to the ventilation stack to be monitored. The shed is of commercial manufacture intended for consumer use for garden tools, etc., and is of low cost. Sheds of this type are easily assembled, readily accommodate the installation of shelving, and can be modified to meet other special needs.
A major activity for MiniBooNE since June has been the completion of the safety review activities. This has included the formal safety assessment process including an extensive shielding assessment. Members of the project; the Fermilab environment, safety, and health (ES&H) staff; the Department of Energy (DOE) Fermi Area Office; and the DOE Chicago Operations Office worked together to provide the necessary assurance of safe operation of this experiment. Following this period of intense and necessary, but procedural, activity, the first beam was delivered to the experiment's target on August 24. On September 9, the experiment announced its first observation of neutrino events. The rapid progress of the experiment is a reward to all who participated in the environment and safety review activities.
Tevatron Collider Run II Progress
While much attention has been focused on MiniBooNE, the highest priority of the Fermilab physics research program is that of Tevatron Run II. The operation of the Tevatron as a proton-antiproton collider is a technologically challenging task. To reach the goals of Run II, numerous incremental improvements in accelerator operation are needed due to the high energies and elevated beam intensities involved. Most of these efforts have the potential to produce enhanced levels of residual radioactivity that must be addressed during maintenance work. To date, the Fermilab Beams Division ES&H radiation safety staff working collaboratively with the division management, its operations personnel, and its support departments has managed to control radiation exposures to levels experienced in the past. The success of accelerator operations is the reward for these efforts. A new record in luminosity of 30.2E30 inverse square centimeters per second was set on September 24, 2002. (Luminosity is a measure of the collision rate of protons and antiprotons in a colliding beam accelerator.) By the time this article appears in the newsletter, it is clearly believed that this record will have been relegated to history.