Mass number and prompt neutron emission of individual fission fragments as functions of nuclear charge, both involving parameters determinable from radiochemical data

Journal Article · Tue Sep 01 00:00:00 EDT 1981 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.24.1055· OSTI ID:6210724

Talat-Erben, M; Tokay, R K

We lack an equation relating fission fragment mass before prompt neutron emission to the mass of the resulting fission product. It is shown that by using conveniently defined auxiliary functions and partly neglecting fine structure effects, expressions may be derived for mass number, charge density, and prompt neutron yields of individual fission fragments. All expressions involve parameters which can be evaluated from radiochemical fission product yield data, without recourse to any physical measurement whatsoever. The expressions for neutron yields from individual fragments reproduce the well-known saw-tooth curve. The fragment mass number as a function of charge is composed of two parallel straight lines with a simple discontinuity at symmetric charge division. Similarly, the fragment charge density versus charge has two branches extending in the heavy and light fragment regions, respectively. The corresponding relationship is a homographic function of charge, and is discontinuous at symmetric charge division, where Dirichlet's theorem applies. In the fission of /sup 238/U, the two branches come closer together at symmetric charge division as excitation energy of the fissioning nucleus increases. The expressions mentioned above have been applied to nine different low excitation energy (< or =14 MeV) fission processes for which selected recommended data are available. CompThe expression predicted by the liquid drop model for mass asymmetry of fission is shown to be identically valid for charge and neutron asymmetry also. Two new identities are also reported. In addition, two quantities are defined, namely, the proton dilution number with respect to nucleons and that with respect to neutrons. It is shown that the arithmetic mean of either of these quantities for the average light and heavy fragments equals the corresponding quantity for the fissioning nucleus, and that this equality holds true with notable accuracy in all low-energy fission processes considered.

• Research Organization: Department of Physical Chemistry, Faculty of Chemical Engineering, Technical University of Istanbul, Istanbul, Turkey
• OSTI ID: 6210724
• Journal Information: Phys. Rev. C; (United States), Vol. 24:3
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CALIFORNIUM 252
FISSION
FISSION FRAGMENTS
MASS
NEUTRON EMISSION
PLUTONIUM 239
THORIUM 232
URANIUM 233
URANIUM 235
URANIUM 238
CHARGE DENSITY
LIQUID DROP MODEL
RADIOCHEMICAL ANALYSIS
TIME-OF-FLIGHT METHOD
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
CALIFORNIUM ISOTOPES
CHEMICAL ANALYSIS
EMISSION
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MATHEMATICAL MODELS
MINUTES LIVING RADIOISOTOPES
NUCLEAR FRAGMENTS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
PLUTONIUM ISOTOPES
QUANTITATIVE CHEMICAL ANALYSIS
RADIOISOTOPES
THORIUM ISOTOPES
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES
652026* - Nuclear Properties &amp; Reactions
A=220 &amp; above
Experimental- Spontaneous &amp; Induced Fission- (-1987)
653006 - Nuclear Theory- Spontaneous &amp; Induced Fission