Angular momentum of fission fragments in low energy fission of actinides

Journal Article · Sat Jan 01 00:00:00 EST 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.71.014304· OSTI ID:20695867

Naik, H; Dange, S P; Singh, R J ^[1]

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1. Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)

Independent isomeric yield ratios (IYR) of {sup 128}Sb, {sup 130}Sb, {sup 132}Sb, {sup 131}Te, {sup 133}Te, {sup 132}I, {sup 134}I, {sup 136}I, {sup 135}Xe, and {sup 138}Cs have been determined in fast neutron induced fission of {sup 232}Th, {sup 238}U, {sup 240}Pu, and {sup 244}Cm as well as in thermal neutron induced fission of {sup 232}U and {sup 238}Pu using radiochemical and offline {gamma}-ray spectrometric techniques. From the IYR, fragment angular momenta (J{sub rms}) have been deduced using a spin-dependent statistical model analysis. These data along with the literature data for {sup 230}Th*, {sup 234}U*, {sup 236}U*, {sup 240}Pu*, {sup 242}Pu*, {sup 244}Cm(SF), {sup 246}Cm*, {sup 250}Cf*, and {sup 252}Cf(SF) for fifteen even-Z fissioning systems show the following important features: (i) The J{sub rms} of the odd-Z fission products are higher than those of the even-Z fission products, indicating the odd-even effect. For both the odd-Z and even-Z fission products, the J{sub rms} increase with Z{sub F}{sup 2}/A{sub F}. (ii) The J{sub rms} of fragments with spherical 50-p and 82-n shells are lower compared to those of fragments outside the spherical shell, indicating the effect of shell closure proximity. (iii) The J{sub rms} of the fission products increase with mass number in spite of fluctuations in shell closure proximity and odd-even effects but do not show any correlation with the neutron emission curve. (iv) In all fifteen even-Z fissioning systems from Th to Cf, the yield-weighted J{sub rms} values show an anticorrelation with the elemental yields. (v) The odd-even fluctuation on J{sub rms} does not change drastically from Th to Cf, unlike the proton odd-even effect ({delta}{sub p}) which decreases significantly with the increase of Coulomb parameter (Z{sub F}{sup 2}/A{sub F}{sup 1/3})

• OSTI ID: 20695867
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 71, Issue 1; Other Information: DOI: 10.1103/PhysRevC.71.014304; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDES
ANTIMONY 128
ANTIMONY 130
ANTIMONY 132
CALIFORNIUM 252
CORRELATIONS
CURIUM 244
FAST NEUTRONS
FISSION
FISSION FRAGMENTS
FISSION PRODUCTS
FLUCTUATIONS
GAMMA RADIATION
IODINE 132
IODINE 134
IODINE 136
NEUTRON EMISSION
NEUTRON REACTIONS
NUCLEAR REACTION YIELD
PLUTONIUM 238
PLUTONIUM 240
SPIN
STATISTICAL MODELS
TELLURIUM 131
TELLURIUM 133
THERMAL NEUTRONS
THORIUM 232
URANIUM 232
URANIUM 238
XENON 135