RADIOCHEMICAL STUDY OF THE BI-209(P,BE-7)HG-203-PROCESS FROM 20 TO 70 MEV VIA IDENTIFICATION OF THE EMITTED PARTICLE (BE-7) AND THE PRODUCT NUCLEUS (HG-203)

The Bi-209(p,Be-7)Hg-203 process was investigated radiochemically over the proton energy range of 20 to 70 MeV via identification of both the emitted particle (7Be) and the product nucleus (Hg-203). It was found that the major part of Be-7 formed originated from interfering reactions on light mass impurity elements (C, N, O). Emphasis was therefore placed on the study of the product nucleus Hg-203. A clear evidence for Hg-203 was obtained. For proton energies up to 55 MeV the formation cross section is very low (74-224 nb) and refers to the real (p,Be-7) reaction on Bi-209. Above 55 MeV, however, the Hg-203 formation cross section increases rapidly, reaching a value of about 4 mu b at 70 MeV. This is presumably due to the onset of the competing several nucleon (4p3n) emission process.