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Fermilab has two major construction projects currently underway that relate directly to the high-energy physics research program. The purpose is to provide new, high intensity facilities in which to study neutrinos with the specific goal of determining if they have mass. If the three kinds of neutrinos (electron neutrino, muon neutrino, and tau neutrino) are found to have nonzero rest mass, then during time, they will transform from one kind into another or, "oscillate". If the neutrinos do, indeed, turn out have a small but nonzero rest mass and thus "oscillate", then the experiments will direct their attention toward precision measurements of neutrino properties. The level of excitement of this part of the field of particle physics has increased greatly during the past few years by well-publicized experimental results found at Los Alamos (the LSND experiment) and in Japan (the Super-Kamiokande experiment also called K2K).
One of these projects involves the construction of a new beam line to deliver 8 GeV protons from the Fermilab Booster synchrotron to a new target hall. The primary detector will consist of a large tank of liquid scintillator. The project is called "BooNE" for "Booster Neutrino Experiment" and its initial stage is called "MiniBooNE". (This choice of nomenclature by the experiment obviously allows room for expansion!) The civil construction began in November 1999 and is well underway. This audience may enjoy perusing the public portions of the BooNE website, particularly the pages on detector construction that include many pictures. This is called a "short baseline" experiment because the production of the neutrinos and their detection all occurs within the confines of the Fermilab site.
The other project is the Neutrinos at the Main Injector, called NuMI for short. This project centers around the construction of a transport line to deliver 120 GeV protons from the Fermilab Main Injector to a new target station where the neutrinos will be produced. The neutrinos will be directed downward and northwestward through the Earth toward the Soudan Underground Laboratory in northeastern Minnesota. The experiment being planned to use this facility is called the Main Injector Neutrino Oscillation Search (MINOS). The neutrinos will be studied using both large amounts of magnetized iron and plastic scintillator in detectors located both on the Fermilab site and at the Soudan Underground Laboratory. Hence, this is a "long baseline" experiment. The latter facility is being enlarged to accommodate this experiment. Differences in the distributions of the neutrinos of a particular type at these two locations would be evidence of "oscillations" and hence of a finite rest masses for these elusive particles. The reader might want to check out the public sections of the NuMI/MINOS website. The associated civil construction commenced this spring. As of this writing, the actual tunneling through the bedrock underlying the Fermilab site has begun. This project represents the first such tunneling at Fermilab. All previous construction here has been by "cut and fill" methods in the glacial till which underlies this site.
Both of these projects have raised significant environment, safety, and health issues. Aside from the occupational safety and environmental protection issues related to "deep" tunneling, the completed facilities when operated will utilize significantly higher beam powers than have been encountered previously at Fermilab. The prompt radiation fields are adequately handled by passive shielding. For NuMI, the target station is also located rather deep underground. A more troublesome feature of both projects is that the levels of residual radioactivity will be significantly greater than those previously encountered at Fermilab. Much effort has already gone into the design of components in order to achieve improved reliability and the ability to handle "hot" components remotely in order to adequately address occupational radiation exposures. Likewise, an intense effort has gone into the control of the activation of soil or rock and the activation of the air that will be present in the target region. The environmental radiation must, of course, be controlled to be well within regulatory standards. This work has required a significant amount of teamwork between project personnel and radiation and environmental protection specialists with the Fermilab ES&H Section. It is safe to say that the spirit of the ALARA principle is being followed throughout this work.