Microbeam irradiation has been a growing area of interest in recent years. Microbeam techniques provide radiobiology researchers with the capability of irradiating cells and even subcellular regions with precise doses over precise time intervals. A variety of systems exist using beams of various ions, X-rays, as well as electrons. Multiple locations are irradiated by scanning the particle or photon beam or by translating the cell targets over the beam. While each of these has its own advantages no one has yet demonstrated a multi-beam system, which could increase experimental efficiency and versatility.

We have been working to develop a carbon nanotube (CNT) based multi-pixel cellular irradiator to demonstrate this as yet unfulfilled possibility. Formation of the microbeam via carbon nanotube field emission represents a great advantage in that the beam generation can take place in a compact area, has significant advantages over thermionic electron generation, and is readily scaleable using microfabrication methods. Use of CNT based electron field emission along with other microfabrication techniques will readily facilitate the development of a multi-pixel system and allows for a greater degree of miniaturization as compared to other systems, particularly those based on particle accelerators.

The CNT based system provides reliable, controllable electron beams with excellent dose rate capabilities. With the potential for smaller, more accessible systems this project demonstrates a development that could make microbeam irradiation available to a broader group of scientists, accelerating the growth of knowledge about the effects and use of radiation on cells and the human body.