RADIOLOGICAL RESEARCH ACCELERATOR FACILITY (RARAF)

The overall technological goal is to upgrade our unique single-particle microbeam facility to improve the spatial resolution from +/- 3.5 mum, and to allow the use of more densely-ionizing radiations (i.e. heavier ion beams, with stopping powers from 15 to 4,500 keV/mum), compared with our current beams of H and He ins (stopping power range 15 to 200 keV/mum). The main specific technological goals are: 1. replacing the current physical collimator system with electrostatic lenses, that we will design and build. 2. replacing the current multiple-magnet beam transport system with a single magnet; 3. designing and building an on-line beam-shape verification system; 4. improving our cellular/sub-cellular optical identification system to a level commensurate with the +/- 0.3 mum resolution of the microbeam; 5. replacing the current ion source with a laser ion source that we shall design and build, allowing high charge-state ion bemas of essentially any element to be accelerated; 6. design/optimization/fabrication of the ion transport system to function independently of the accelerated ion type; 7. design/fabrication of a new differentially-pumped gaseous ion detector, within the beam optics system. In collaboration with investigators from outside and within Columbia University, 28 collaborative- and service-outgrowths of funded NIH research, many at the current RARAF facility. 7 of these projects originate from Columbia University, and 21 from other institutions. Training and information dissemination will continue to be important components of this resource. Training will continue to play an important role at the undergraduate, graduate, post doctoral, and senior scientist levels. Information dissemination will continue through organizing bi- annual international microbeam workshops, talks at national and international meetings, written and web-based user information, and peer- reviewed publications.