THE FEASIBILITY OF HEAVY CHARGED‐PARTICLE MICROSCOPY*

Abstract

The idea of applying accelerated heavy ions to microscopy was developed and proposed about ten years ago. The advancement of heavy-ion accelerator technology has promoted development of a new imaging system for diagnostic radiology. The plastic nuclear track-etch detector technique has recently been used for microradiography with low-energy heavy ions, and images of various biological specimens, including living plant cells, have been obtained. A simple and straightforward theoretical analysis indicates that a resolution of a few hundred angstroms may be reached in imaging a living cell with heavy particles of 10-..mu..m range. At present, however, such a high resolution is not expected, since the radiation damages to the specimen can be very severe at high doses. With certain improvement the present heavy-ion microradiography technique, nevertheless, can be used for gaining information on the density of organelles in a living cell and for obtaining a three-dimensional image of a living cell. A preliminary study on contrast mechanisms suggests that the heavy-ion microscope may give an equal or better contrast than the electron microscope. Other possible means of getting information with heavy-ion microscopes should be explored also. An energy or range analysis of heavy particles that passed through the biological specimen withmore » a proper detector, for example can provide additional information of interest.« less