Radioactivity ofBe10

The formation of radioactive ${\mathrm{Be}}^{10}$ by the ($d,p$) reaction from beryllium has been observed. The assignment of the activity to beryllium is the result of very careful chemical separations. ${\mathrm{Be}}^{10}$ emits negative electrons with an upper limit of 560±50 kev (end point in Al = 180±20 mg/${\mathrm{cm}}^2$). The half-life is very long; data are given from which its value could be computed if the yield were known.