The 16th International Conference on Accelerator Mass Spectrometry

Here we search the 28Si doubly charged negative ion (28Si DCNI) with Accelerator Mass Spectrometry (AMS). Five kinds of silicon including samples made of Si, Si+Fe, Si3N4, SiO2+Fe, and Si3N4+Fe were prepared to find 28Si DCNI. These samples were loaded into an AMS, which was a tandem type machine with a negative ion source by cesium sputtering (SNICS). The ions produced from these samples went through the AMS and were measured in ΔE-Eresdual of an ionization detector. The existence of the 28Si DCNI (28Si2-) was originally believed to be in the spectrum of ΔE-Eresdual of the AMS.