The primary goal of this Phase I design study is to develop the design of an accelerator-based neutron source for clinical boron neutron capture therapy (BNCT) using the compact radio-frequency quadruple (RFQ) linear accelerator. This accelerator design study will be completed in collaboration with the Brain Tumor Research Center at the University of in San Francisco (UCSF). The accelerator design will take into account the new boron compounds being developed at UCSF, as well as the lithium neutron production target and epithermal beam moderator being designed by other groups in this field. The required output current of the accelerator will be determined from the medical therapy requirements, and the RFQ will be designed to achieve this current as efficiently as possible. If the current required makes a conventional room temperature structure too difficult to achieve, the final RFQ linac design may take advantage of a new superconducting RFQ structure currently under development. An additional goal of the Phase I program is to complete the plans for a Phase 1I prototype system that could be used in a clinical setting at UCSF to test new targets and moderators, carry out in vitro and in vivo radiobiologic studies on the new boron compounds, and demonstrate the clinical effectiveness of this treatment modality using an accelerator.Awardee's statement of the potential commercial applications of the research: The study will result in the design of a high-current RFQ linac suitable for clinical treatment of malignant brain tumors using BNCT, particularly when combined with the boron compounds being developed at UCSF. Such an accelerator would be an invaluable component of a hospital-based brain cancer therapy system and would have immense commercial potential in the medical control of this form of cancer, which presently has no effective cure.National Cancer Institute (NCI)