CROSS-SECTION MEASUREMENTS FOR THE (HE-3,P) NUCLEAR-REACTION ON B ANDN BETWEEN 2 AND 4 MEV

Cross section measurements have been made for several proton groups fr om the (He-3,p) nuclear reaction on boron and nitrogen. Incident energ ies between 2 and 4 MeV and angles of 90 degrees and 135 degrees were used. A 1.5 mm thick surface barrier detector, covered to stop elastic ally scattered He-3 ions, was used to detect the high energy protons f rom these reactions. The proton energy was as high as 20 MeV in the ca se of a boron target. We propose the use of these reactions for quanti tative elemental areal density determination in thin film analyses.