Gamma-ray multiplicity distribution in ternary fission of²⁵²Cf

Abstract

From multiparameter data obtained at Lawrence Berkeley National Laboratory, the integral characteristics of the prompt γ-ray emission were extracted for tripartition of 252Cf with He, Be and C being the third light charged particle. We used multifold γ-ray coincidence spectra for the determination of γ-ray multiplicities assuming a Gaussian distribution for γ-ray multiplicity. The multiplicity distribution characteristics, i.e. mean multiplicity and its dispersion were obtained by minimizing with respect to the calculated values of probabilities of multifold γ-ray coincidences using a combinatoric method. Comparison with the known experimental data from binary fission was made. Further, we investigated dependencies of the mean γ-ray multiplicity on the kinetic energy of the light charged particle. The mean γ-ray multiplicity for He ternary fission is found to increase rapidly with increasing kinetic energy of He in the region less than 11 MeV and then decrease slowly with increasing kinetic energy of He. The anomalous behaviour of γ-ray emission is discussed. The mean γ-ray multiplicity was determined for the first time for Be and C ternary fission. For Be, the γ-ray multiplicity as a function of kinetic energy was obtained as well.

The emission probabilities of long range alpha particles from even–even244–252Cm isotopes

“…In the cold valley, the minima is found for the fragment combinations with mass number A 1 = 4 He, 10 Be, 14 C, 16 C, 20 O, 22 O, 24 O, 26 Ne, 30 Mg, 32 Mg, 34 Si, 36 Si, 40 S, 42 S, 44 Ar, 46 Ar, 48 Ar, 50 Ca, 52 figure 4. The hatched bars belong to odd mass numbers and the dark ones belong to even mass numbers.…”

“…The minima obtained in the cold valley for the fragment combinations with mass number A 1 = 4 He, 10 Be, 14 C, 16 C, 18 C, 20 …”

“…In the cold valley the minima is found for the fragment combination with A 1 = 4 He, 6 He, 10 Be, 12 Be, 14 C, 16 C, 18 C, 20 In figure 3, the relative yield is plotted for all the considered isotopes of curium as a function of mass numbers A 1 and A 2 . The most probable fragment combinations occur with the alpha accompanied ternary fission is labeled.…”

“…Taking Coulomb and proximity potential [31] as the barrier the ternary fragmentation of 242 Cm emitting light clusters 4 He, 10 Be and 14 C have been studied with fragments in equatorial configuration. In the present work, we are interested in the study of alpha accompanied ternary fission of 244 Cm, 246 Cm, 248 Cm, 250 Cm and 252 Cm isotopes and we have considered the equatorial configuration of fragments, as the experimental studies of Oertzen et al [32] revealed that the equatorial configuration is the preferred configuration for the ternary fission accompanying light charged particles 4 He, 10 Be etc.…”

“…The transition towards three equal fragment partitions was computed using the three centre shell model. Jandel et al [14] studied the γ-ray multiplicity for the tripartition of 252 Cf with He, Be and C as the third light charged particle. Andreev et al [15] calculated the charge distributions for the ternary fragmentation of 252 Cf and induced ternary fission of 56 Ni.…”