Kamran Vaziri and Don Cossairt
The Fermi National Lab's (Fermilab's) accelerator shutdown is over. With significant help from across the laboratory, the teams in the Accelerator Division completed a staggering number of jobs during the shutdown. These many jobs, often in tight quarters, have been carried out safely. The same was true for the very complex activities undertaken by the DZero collaboration, especially the delicate installation of the innermost layer of the silicon detector. The Tevatron is up and running days ahead of schedule and with excellent luminosities.
The average collective weekly dose during the shutdown was about 1 person-rem, consistent with expectations of shutdown planning. Of course during the last two weeks of the shutdown the trends were downward, since many of the major shutdown tasks were either done (e.g., NuMI work) or nearly complete. The above doses include doses resulting from this task in the hottest location that is near a Lambertson magnet where the radiation field is several hundred mR/hr. The large-aperture quadrupole installation project has resulted in the accumulation of about 1 person-mrem. However, in the long term, these large-aperture magnets allow better tuning of the intense Main Injector beam, which results in lower losses and less residual radioactivation of the equipment--an ALARA measure.
Recently Fermilab was presented with National Safety Council's (NSC's) Occupational Excellence Achievement Award. According to the Bureau of Labor Statistics, Fermilab's injury rate is among the best of all research and development companies in physical, engineering, and life sciences. This earned Fermilab an NSC Occupational Excellence Achievement Award for 2005. The award is based on the rate of injuries that resulted in days away from work per 100,000 hours worked. Fermilab has met the NSC criteria for a number of years, and began submitting their data to the NSC for consideration 3 years ago. Since that time, Fermilab has been presented with this award each year.