Application of 14N(3He,4He)13N nuclear reaction to nitrogen profiling

In this paper the 14N(3He,4He)1'3N reaction is proposed for nitrogen profiling in metals and other materials. The beam energy is chosen to be 4.65 MeV in order to use the high cross section. Two types of particle filtering are used: a 25 μm thick mylar in front of the detector to avoid backscattered particle pileup and reduced detector bias voltage to avoid full energy detection of high energy protons produced by competing reactions. The depth resolution is about 150-200 nm and the sensitivity is better than for the 14N(d,4He)12C reaction. The low level of neutron radiation background allows use of this reaction in accelerator laboratories without radiation shielding. 11 refs., 5 figs