An essential contribution of the Core is the design and construction of facilities at the Radiological Research Accelerator Facility (RARAF), so that alpha particles of the appropriate energy, dose, and dose rates are available for the radon simulation for irradiations required for the biological Projects proposed. The physicist responsible for the facilities' design and construction will also collaborate with each of the biologists and molecular biologists to ensure that appropriate irradiation protocols are used, and that interpretation of the physical dosimetry is sensibly done. The core also provides an administrative framework and secretarial help for the ordering of supplies and the typing of manuscripts. The Bio-Instrument (machine) Shop is a vital need in the design, building, and maintenance of the sophisticated computer-controlled irradiation facility. Last, but not least, the core represents a vehicle for the exchange of information and the comparison of results from the various projects, bringing together investigators from several different departments and programs within the Comprehensive Cancer Center.