Particle Accompanied 252Cf Fission:
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-particles and about
10% tritons, the remaining fraction being constituted by a large
variety of particles. The relative emission probabilities of the
various ternary particles are summarized in table 1
for the spontanous fission of 252Cf. The hydrogen and helium
isotopes are always responsible for 99% of the ternary particle
yield, while the heavier particles are very rarely emitted. Nevertheless,
strong yield differences are observed between neighboring particles.
In table 1, both the first and second moments of the
energy distribution of ternary particles are also given. The main feature
of the spectrum is a fairly wide Gaussian shape, with a slight excess
of intensity at low energies. It is apparent that mean energies of the
measured ternary particles increase with the nuclear charge and decrease
within each element with increasing mass. The observed decrease of kinetic
energy with increasing mass and constant Z can be understood by assuming
very similar initial conditions for the vatious ternary particles. Indeed,
for a given initial energy, the heavier particles will move more slowly,
allowing the fission fragments to move further away before the particle
is fully accelerated.
