A study of the /sup 235/U(n,f) cross section in the 3 to 30 MeV energy region

Conference · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6907053

Carlson, A D; Wasson, O A; Lisowski, P W; Ullmann, J L; Hill, N W

The /sup 235/U(n,f) cross section is often considered the most favorable of the neutron cross section standards. Above a few MeV, however, the uncertainties are still unacceptably high, except for the 14 MeV region. In an effort to improve the accuracy of this cross section, measurements have been initiated at the new target 4 facility at the Los Alamos National Laboratory (LANL) 800 MeV proton accelerator. This target provides an intense source of high energy neutrons at the 20 meter flight path used in the present study. The fission reaction rate is determined with a fast parallel plate ionization chamber designed at LANL while the neutron fluence is being measured with an annular proton recoil telescope whose properties were carefully studied earlier at the National Bureau of Standards (NBS). This detector provides satisfactory performance for neutron energies up to about 30 MeV. Possible use of this detector at higher neutron energies where the recoil proton range exceeds the solid state detector thickness is being investigated. The measurements provide the shape of the /sup 235/U(n,f) cross section relative to the hydrogen scattering cross section. The data will be normalized to the very accurately known values at 14 MeV. Experimental tests, diagnostic studies and preliminary cross section determinations have been completed and will be reported. 7 refs., 5 figs., 1 tab.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6907053
• Report Number(s): LA-UR-88-1896; CONF-880546-29; ON: DE88014450
• Country of Publication: United States
• Language: English

Related Subjects

652020* -- Nuclear Properties & Reactions
A=220 & above
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCELERATORS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BARYON REACTIONS
CROSS SECTIONS
DATA
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
FISSION
FISSION CHAMBERS
HADRON REACTIONS
HEAVY NUCLEI
INFORMATION
IONIZATION CHAMBERS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LI-DRIFTED DETECTORS
LI-DRIFTED SI DETECTORS
MEASURING INSTRUMENTS
MINUTES LIVING RADIOISOTOPES
NEUTRON DETECTORS
NEUTRON FLUENCE
NEUTRON REACTIONS
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUMERICAL DATA
PERFORMANCE TESTING
PROTON RECOIL DETECTORS
RADIATION DETECTORS
RADIOISOTOPES
SEMICONDUCTOR DETECTORS
SI SEMICONDUCTOR DETECTORS
TARGETS
TESTING
URANIUM 235
URANIUM 235 TARGET
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES