Experimental nuclear cross sections for spacecraft shield analysis

Experiments have been performed to validate and to supplement the intranuclear cascade model as a method for estimating cross sections of importance to spacecraft shield design. The experimental situation is inconclusive particularly for neutron-producing reactions, but is relatively sound for reaction cross sections and for proton spectra at several hundred MeV at medium forward angles. Secondary photon contributions are imprecisely known

Rapid computation of specific energy losses for energetic charged particles

Rapid computation of specific energy losses for energetic charged particle

Nuclear reaction cross sections for spacecraft shield design

Nuclear reaction cross section data for spacecraft shield design, and for determining radiation dose effect on astronaut

Establishing an energy scale for pulse-height distributions from gamma-ray spectrometers based on inorganic scintillators

Energy scale for pulse height distributions from gamma ray spectrometers based on inorganic scintillator

Differential cross sections at forward angles for hydrogen and helium particles from 62 MeV protons incident on Ni-60

Tabulated differential cross sections are presented for the production, at angles of 15, 20, 25, and 40 deg, of proton, deuteron, triton, helium-3, and alpha particles from Ni-60 bombarded by 62-MeV protons. Continuum cross sections are listed in about 1-MeV bins for energies above lower cutoffs which range from 4 to 15 MeV for the different types of exit particles. Only the integral cross section is known for a considerable energy range within each spectrum. The proton, deuteron, and alpha particle cross sections are the same in the continuum range region above the evaporation peak as those cross sections previously observed for Fe-54 and Fe-56, but the corresponding yield of tritons is higher from Ni-60 and Fe-56 than from Fe-54

Tabulated cross sections for hydrogen and helium particles produced by 61-MeV protons on Fe56

Tabulated cross sections for hydrogen and helium particles produced by 61 MeV on iron 5

Absolute Efficiency Measurements of NE-213 ORGANIC Phosphors for Detecting 14.4 and 2.6 Mev Neutrons

Efficiency measurements of organic phosphor scintillator for detecting 14.4 and 2.6 MeV neutron

Extended covariance data formats for the ENDF/B-VI differential data evaluation

The ENDF/B-V included cross section covariance data, but covariances could not be encoded for all the important data types. New ENDF-6 covariance formats are outlined including those for cross-file (MF) covariances, resonance parameters over the whole range, and secondary energy and angle distributions. One ''late entry'' format encodes covariance data for cross sections that are output from model or fitting codes in terms of the model parameter covariance matrix and the tabulated derivatives of cross sections with respect to the model parameters. Another new format yields multigroup cross section variances that increase as the group width decreases. When evaluators use the new formats, the files can be processed and used for improved uncertainty propagation and data combination. 22 refs

Quantification of uncertainties in the parameters of a long-term energy model

Even if the form of an energy-economy model's equations can be assumed to specify correctly our technological processes and the relevant behaviors of our society over the necessary time range, there is uncertainty in model results induced by our imperfect knowledge of the numerical values of the model's parameters and input data. Some of this uncertainty is typically covered by provision of alternative scenarios with assumptions but, up to now, modelers have rarely dealt in detail with the inherent uncertainty of input data. However, when model output or response can be represented by a first-order Taylor expansion in the input data about the nominal solution point, knowledge of the variance-covariance (uncertainty) matrix of the input data is sufficient to determine the uncertainty in the computed response induced by the input uncertainties. Some guidelines are given for the evaluation of the required input-uncertainty matrices. Illustrative examples are given from the authors' beginning efforts to develop an uncertainty matrix for the important parameters of the Long-term Energy Analysis Package used within the Energy Information Administration of the Department of Energy