Production test of highly polarized ¹²N beam for materials science use

Production of spin polarized short-lived nucleus ¹²N (I^π=1⁺, T_1/2=11 ms) using heavy ion reactions has been performed. Typical polarization of about -25% and -10% through the projectile fragmentation Be(¹⁴N, ¹²N)X and the charge exchange CH₂(¹²C, ¹²N)X processes, respectively, was obtained at a primary-beam energy of 70A MeV. The present study proved that the combination of a ¹²C beam and a proton target gives the maximum figure of merit for polarized ¹²N beam production and is the most promising for materials science use of ¹²N as a nuclear probe. (author)