Fragment velocities, energies, and masses from fast neutron induced fission of /sup 235/U
We report on a complete (2E,2v) experiment for fast neutron induced fission on /sup 235/U. The energy dependence of fragment properties so far known only for thermal neutron induced fission is studied. Experimental problems as well as difficulties in data analysis are considered in detail in order to obtain clean and unbiased results. In particular, a self-consistent determination of the fragment total kinetic energy (E/sub K/,tot) was achieved by comparing the results obtained via the respective velocities and pulse heights. We find systematic discrepancies of 2 MeV if E/sub K/,tot is determined from the observed pulse heights with the calibration scheme of Schmitt et al. Therefore, refined calibration constants were deduced by comparison with accurate radiochemical mass yields. Measurements were performed at neutron energies of 0.50 and 5.55 MeV. Our results include mean values of fragment properties before and after neutron evaporation, e.g., of fragment velocities and masses, total kinetic energies, and the respective variances. We also show the distributions of fragment mass, of E/sub K/,tot, and of the variance of E/sub K/,tot. In addition, the number of prompt fission neutrons ..nu.. is given as a function of fragment mass. Our resolution of 2.1 mass units reveals fine structure not only in the fragment mass distribution but also in E/sub K/,tot(A() and ..nu..(A(). For the lower neutron energy of 0.50 MeV the present results compare reasonably well with similar measurements performed with thermal neutrons. Apparently the 0.5 MeV increase in saddle point excitation does not alter the results significantly.
- Research Organization:
- Universitaet Tuebingen, Physikalisches Institut, Tuebingen, Federal Republic of Germany
- OSTI ID:
- 6823871
- Journal Information:
- Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 29:3; ISSN PRVCA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Absolute mass calibration of fission product distributions measured with the E-$v$ method
THE NUMBER OF PROMPT NEUTRONS AND THE KINETIC ENERGY OF FISSION FRAGMENTS FROM THE LOW-ENERGY FISSION OF U$sup 23$$sup 5$
Related Subjects
A=220 & above
Experimental-- Spontaneous & Induced Fission-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
BARYONS
DATA
DATA ANALYSIS
ELEMENTARY PARTICLES
ENERGY
ENERGY DEPENDENCE
ENERGY RANGE
EXPERIMENTAL DATA
FAST FISSION
FERMIONS
FISSION
FISSION FRAGMENTS
FISSION NEUTRONS
HADRON REACTIONS
HADRONS
INFORMATION
KEV RANGE
KEV RANGE 100-1000
KINETIC ENERGY
MASS SPECTRA
MEV RANGE
MEV RANGE 01-10
NEUTRON REACTIONS
NEUTRONS
NUCLEAR FRAGMENTS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEONS
NUMERICAL DATA
SPECTRA
TARGETS
URANIUM 235 TARGET