Magnetic Analysis of the Long-Range Particles from Fission ofU235

The long-range particles from pile-neutron fission of ${\mathrm{U}}^{235}$ were studied with a high-resolution magnetic spectrograph. The particles were detected with a CsI(Tl) crystal scintillator; differential pulse-height analysis was used. Scintillation pulse height vs $H\rho$ data show that the particles have the same value of $\frac{e^2}{m}$ as alpha particles. The range-energy relationship for the particles in aluminum was studied; this showed that the particles have the same value of $m{e}^2$ as alpha particles. Since the long-range particles have the same $\frac{e^2}{m}$ value and the same $m{e}^2$ value as alpha particles, they have the same values of $e$ and $m$; this confirms that they are alpha particles as was indicated by previous studies. The energy distribution of the particles as determined here is in good agreement with previous determinations by other methods. An extensive search revealed no fine structure in the energy distribution. The shape of the energy distribution indicates that the particles are formed at the instant of fission.