BINARY FISSION STUDIES OF HELIUM-ION-INDUCED FISSION OF Bi$sup 209$, Ra$sup 226$, AND U$sup 23$$sup 8$

Journal Article · Mon Apr 13 04:00:00 EST 1964 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.134.B90· OSTI ID:4073668

Unik, J P; Huizenga, J R

The kinetic energies of coincident fission fragments were measured for helium-ion-induced fission of Bi/sup 209/ Ra/sup 226/ and U/sup 238/ with gold surface-barrier detectors and an Argonne three-parameter analyzer. The data obtained at each bombarding energy were analyzed to give total kinetic energy and mass yield distributions for fixed values of the average total kinetic energy, and total kineticenergy distributions as a function of heavy fragment mass M/sub H. The mass yield distributions for Bi/sup 209/, U/sup 238/, and Ra/sub 226/ are single, double, and triple humped, respectively. The total kinetic- energy release for Bi/sup 209/ fission decreases smoothly with increasing values of M/sub H/ and its variance remains constant. The total kinetic energy as a function of MH for all the bombardments of Ra/sup 226/ and U/sup 238/ show structure with a maximum value at M/sub H/ = 135, while each bombardment gives a maximum in the variance of the total kinetic energy at M/sub H/ = 131. This structure in the kinetic energy for Ra/sup 226/ and U/sup 238/ is interpreted in terms of shell structure in the heavy fragment. The larger kinetic energy observed for symmetric fission of heavy elements with energetic particles over that observed for thermal neutron fission is assumed to be due to a smaller effective separation of charge centers at the scission configuration. This effect may possibly result from a temperaturedependent viscosity and tensile strength of the nuclear fluid and leads to the interesting speculntion that information on these parameters may be inferred from nuclear fission data. The full width at half-maximum height in the total kinetic-energy distribution for 42- Mev helium-ioninduced fission of Bi/sup 209/ is 16 plus or minus 1 Mev (corrected for neutron emission and experimental dispersion) in excellent agreement with a theoretical calculation of Swiatecki and Nix. (auth)

• Research Organization: Argonne National Lab., Ill.
• NSA Number: NSA-18-015278
• OSTI ID: 4073668
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 134; ISSN PHRVA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BISMUTH 209
CONFIGURATION
CRYSTAL COUNTERS
DETECTION
DISTRIBUTION
ELECTRIC CHARGES
ENERGY RANGE
FISSION
FISSION PRODUCTS
GOLD
HELIUM
ION BEAMS
MASS
MEASURED VALUES
MEV RANGE
NUCLEAR MODELS
NUMERICALS
PHYSICS
RADIUM 226
REACTION KINETICS
SHELL MODELS
TEMPERATURE
THERMAL NEUTRONS
URANIUM 238
VELOCITY