Bonner sphere measurements of D20-moderated and 252Cf source

On major experimental areas in the new research reactor facility at the University of Texas at Austin (UT) is a 9-m cubical room designed to house a variety of radiation experiments. The room has 1.3-m-thick concrete walls for radiation shielding and provisions for the remote control of radiation experiments. Sources currently available for use in the room include a neutron generator, various strengthed 252Cf sources, and several large 137Cs sources. A D2O sphere based on the National Institute of Standards and Technology (NIST) D2O-moderated 252Cf source was acquired recently for use in neutron research in the areas of dosimetry and calibration. Several other spherical shells are available for measurements with a 252Cf source or the neutron generator. Bare 252Cf and D2O-moderated 252Cf will be used in the room on a regular basis to calibrate neutron survey instruments as well as to continue ongoing research on neutron dosimeter and moderating detector response. The work presented in this paper involves the preliminary investigation into the response of individual Bonner spheres to D2O-moderated 252Cf. As such, it gives insight into the room-return characteristics of this new experimental area and the adequacy of the UT-calculated response matrix for Bonner spheres