A new detection method in studying penetration depth of low－energy heavy ions in botanic samples

1 INTRODUCTIONLow-energy heavy ion imPlantation has fOund its new application in crop breedingin recent years. It has been reported that the imPlantation of 20ro300 keV N+ ions intodry plant seeds such as rice and wheat in the dose ral1ge of 1015-1017 ions/cm' producedsignilicant inheritable mutation effe.t,[1]. The mutation effects axe guessed to be inducedby the direct interaction between energetic imPlanted ions and the DNA molecules in theembryo of seeds. However, based on the LS…

A new detection method in studying penetration depth of low-energy heavy ions in botanic samples

A new detection method has been applied to study the penetration depth of low-energyheavy ions in botanic samples. Highly oriented pyrolytic graphite (HOPG) pieces were placed behind the target samples with certain thickness to receive energetic penetrated ions during the irradiation. After irradiation, statistic number density of protrusion-like damage induced by energetic penetrated ions can be ob tained through scanning tunneling microscope (STM) observation on the surfaces of HOPG. The results of test indicate that the detection limit can be as low as 1.0× 109 protrusions/em2. With the method, the penetration depth of at least 60μm can be detected in kidney bean slices irradiated by N+ ions with dose of 0.3-3× 1017ions/cm2.