Long-Range Particles ofZ=1 to 4Emitted During the Spontaneous Fission ofCf252

The long-range particles emitted during the spontaneous fission of ${}_{}{}^{252}{}_{}{}^{}\mathrm{Cf}$ have been investigated, confirming the emission of ${}_{}{}^1{}_{}{}^{}\mathrm{H}$, ${}_{}{}^2{}_{}{}^{}\mathrm{H}$, ${}_{}{}^3{}_{}{}^{}\mathrm{H}$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$, ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, and ${}_{}{}^6{}_{}{}^{}\mathrm{He}$. In addition it was found that ${}_{}{}^8{}_{}{}^{}\mathrm{He}$, ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^8{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^9{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}$, and probably other isotopes of Be are also emitted. A detailed search for the emission of the heavy-helium isotopes ${}_{}{}^7{}_{}{}^{}\mathrm{He}$, ${}_{}{}^9{}_{}{}^{}\mathrm{He}$, and ${}_{}{}^{10}{}_{}{}^{}\mathrm{He}$ yielded no evidence for their particle stability. Relative intensities and most probable energies for all emitted hydrogen and helium isotopes (except ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) and for the Li and Be ions were obtained.