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Neutron spectra calculations from pulse height due to neutron interactions with protons and alpha particles in silicon charged particle detector
Comparison of measurements and calculations of fast neutron spectra from a radioactive neutron source inside spheres of Mo or Pb and from a cylindrical reactor containing a thick Pb or Mo reflector are used as a test of ENDF cross sections. The sphere leakage spectra were measured at a sphere-to-spectrometer distance of 2 meters using a 54 Ci spherical Am-Be neutron source. Reactor leakage spectrum measurements were made at the surface of the ZP-1 reactor when bare, with a Pb radial reflector 21 cm thick, and with a metallic Mo radial reflector 10 cm thick. In the case of the thin Mo sphere there is agreement between the calculation and measurement. The Pb calculation is much lower than the measurement except at the highest neutron energy. Two-dimensional calculations of reactor spectra result indicate that the reactor source is reasonably well known. Significant differences in leakage spectrum shape for both Mo and Pb reflectors suggest that there are large uncertainties in the inelastic cross sections for Pb and some for Mo.
Neutron spectra for various thicknesses of liquid hydrogen
Proton recoil measurements of PuBe source neutron spectra
Proton recoil distributions were obtained by using organic liquid scintillators of different size. The measured distributions are converted to neutron spectra by differentiation analysis for comparison to the unfolded spectra of the largest scintillator. The approximations involved in the differentiation analysis are indicated to have small effects on the precision of neutron spectra measured with the smaller scintillators but introduce significant error for the largest scintillator. In the case of the smallest cylindrical scintillator, nominally 1.2 by 1.3 cm, the efficiency is shown to be insensitive to multiple scattering and to the angular distribution to the incident flux. These characteristics of the smaller scintillator make possible its use to measure scalar flux spectra within media high efficiency is not required.
Differential energy flux neutron spectra in liquid hydrogen obtained by time-of-flight techniques
Proton and neutron spectra as measured by Cosmos satellites to determine cosmic radiation doses
Neutron spectra measurement in liquid hydrogen, water cooled fast neutron source, thermal neutron measurements, and liquid hydrogen facility checkout using nitrogen
Neutron-neutron S-wave scattering length from neutron spectra of deuterium bombardment by negative pion giving 2 neutrons and gamma ray
Fast neutron spectra in lead and water shielded reactor, comparing liquid scintillator measurements with discrete ordinates code calculations
Measurement of neutron spectra in liquid hydrogen
Proton recoil measurements of PuBe neutron source spectra, using pressurized hydrogen spherical proportional counter and liquid scintillator measurements
Measurements of MeV neutron were made at the surface of a lithium hydride and depleted uranium shielded reactor. Four shield configurations were considered: these were assembled progressively with cylindrical shells of 5-centimeter-thick depleted uranium, 13-centimeter-thick lithium hydride, 5-centimeter-thick depleted uranium, 13-centimeter-thick lithium hydride, 5-centimeter-thick depleted uranium, and 3-centimeter-thick depleted uranium. Measurements were made with a NE-218 scintillation spectrometer; proton pulse height distributions were differentiated to obtain neutron spectra. Calculations were made using the two-dimensional discrete ordinates code DOT and ENDF/B (version 3) cross sections. Good agreement between measured and calculated spectral shape was observed. Absolute measured and calculated fluxes were within 50 percent of one another; observed discrepancies in absolute flux may be due to cross section errors.
The epithermal portion of an equilibrium neutron spectrum in a planetary body is a function of the water content of its material. The neutrons are produced at high energies but are moderated by elastic and inelastic scattering until they either are captured by surrounding nuclei or escape. We have derived an expression that explicitly shows the dependance of epithermal neutron spectra on water content. Additionally, we compared its predictions to calculations done by Boltzman transport code for infinite media for silicon, oxygen, and a possible lunar composition, and we have obtained very good agreement.
Computerized method using combined codes for neutron spectra evaluation in thermal reactors
Integral test of inelastic scattering cross sections using measured neutron spectra from thick shells of Ta, W, Mo, and Be
Comparison of calculated and liquid scintillation measured fast neutron spectra in layered cylindrical shield of UOF2-water solution reactor
Neutron spectra calculations from proton-nucleus inelastic collisions for 15 to 18 MeV protons