Engineering Papers⌕ Search

Engineering topics

Wilson, J. W.

Publications and source records attributed to Wilson, J. W..

303 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Proton-deuteron double scattering

A simple but accurate form for the proton-deuteron elastic double scattering amplitude, which includes both projectile and target recoil motion and is applicable at all momentum transfer, is derived by taking advantage of the restricted range of Fermi momentum allowed by the deuteron wave function. This amplitude can be directly compared to approximations which have neglected target recoil or are limited to small momentum transfer; the target recoil and large momentum transfer effects are evaluated explicitly within the context of a Gaussian model.

Wilson, J. W.↗
NASA NTRS1974

Geometric correction for spherical ion chambers

The dose at the center and the average dose of a spherical ion chamber were calculated for various inner and outer radii for a radiation spectrum described by E raised to a negative exponent, where the exponent ranges from 2.5 to 7. When the ratio of the chamber's inner radius to the wall thickness is small, the dose at the center does not deviate significantly from the average dose. However, when the ratio equals 5, the center dose exceeds the average dose by about 100% for an exponent of 7, and by about 30% for an exponent of 2.5.

Khandelwal, G. S.↗
NASA NTRS1973

Intermediate energy proton-deuteron elastic scattering

A fully symmetrized multiple scattering series is considered for the description of proton-deuteron elastic scattering. An off-shell continuation of the experimentally known twobody amplitudes that retains the exchange symmeteries required for the calculation is presented. The one boson exchange terms of the two body amplitudes are evaluated exactly in this off-shell prescription. The first two terms of the multiple scattering series are calculated explicitly whereas multiple scattering effects are obtained as minimum variance estimates from the 146-MeV data of Postma and Wilson. The multiple scattering corrections indeed consist of low order partial waves as suggested by Sloan based on model studies with separable interactions. The Hamada-Johnston wave function is shown consistent with the data for internucleon distances greater than about 0.84 fm.

Wilson, J. W.↗
NASA NTRS1973

Proton dosimeter design for distributed body organs.

The design of a real-time rem-rad dosimeter with sufficient generality for inclusion of dose distribution factors for space applications is discussed. This generalized dosimetric system is only slightly more complex than dosimeters in current use.

Khandelwal, G. S.↗
NASA NTRS1973

Intermediate energy nucleon-deuteron scattering theory.

Sloan's conclusion (1969) that terms of the multiple-scattering series beyond single scattering contribute only to S- and P-wave amplitudes in an S-wave separable model is examined. A comparison of experiments with the calculation at 146 MeV shows that the conclusion is valid in nucleon-deuteron scattering applications.

Wilson, J. W.↗
NASA NTRS1973

Intermediate energy nucleon-deuteron elastic scattering

The adequacy of a multiple scattering description of nucleon-deuteron scattering at intermediate energy is examined. Although the multiple-scattering series is expected to converge slowly, model calculations indicate that the higher-order multiple-scattering terms contribute only to the low-order partial waves. The first two terms, nucleon exchange and single scattering, are assumed to describe the high-order partial waves completely. It is assumed that the deuteron is coupled only to the nucleon channel and that the internal structure is adequately defined by a nonrelativistic wave function.

Wilson, J. W.↗
NASA NTRS1972

Isosinglet approximation for nonelastic reactions

Group theoretic relations are derived between different combinations of projectile and secondary particles which appear to have a broad range of application in spacecraft shielding or radiation damage studies. These relations are used to reduce the experimental effort required to obtain nuclear reaction data for transport calculations. Implications for theoretical modeling are also noted, especially for heavy-heavy reactions.

Wilson, J. W.↗