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Shen, B. S. P.

Publications and source records attributed to Shen, B. S. P..

15 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1982

Radio jets in NGC 4151

The relationship between the radio and optical emissions from the nucleus of the Seyfert galaxy NGC 4151 is investigated by mapping the radio radiation from this source at wavelengths of 20 and 6 cm using the Very Large Array of the National Radio Astronomy Observatory. Results show that the radio emission at wavelengths from 20 to 6 cm extend 10'' (950 pc) along a position angle of 72-84 degrees. This nonthermal emission is found to consist of at least six components and is similar to jets observed in other compact extragalactic radio sources. These radio jets appear to be coincident with the optical line emission region in NGC 4151 and are aligned with the position angle of the linearly polarized optical continuum emission.

Johnston, K. J.↗
NASA NTRS1974

Nuclear reactions induced by high-energy alpha particles

Experimental and theoretical studies of nuclear reactions induced by high energy protons and heavier ions are included. Fundamental data needed in the shielding, dosimetry, and radiobiology of high energy particles produced by accelerators were generated, along with data on cosmic ray interaction with matter. The mechanism of high energy nucleon-nucleus reactions is also examined, especially for light target nuclei of mass number comparable to that of biological tissue.

Shen, B. S. P.↗
NASA NTRS1974

A model for astrophysical spallation reactions

A Monte-Carlo model (RENO) for spallation reactions is described which can treat both the spallations induced by a free nucleon and those induced by a complex nucleus. It differs from other such models in that it employs a discrete-nucleon representation of the nucleus and allows clusters of nucleons to form and to participate in the reaction. The RENO model is particularly suited for spallations involving the relatively light nuclei of astrophysical and cosmic-ray interest.

Schmitt, W. F.↗
NASA NTRS1974

Calculation of astrophysical spallation reactions using the RENO model

The RENO model for the Monte-Carlo treatment of astrophysical spallation reactions has been used to generate preliminary cross-sections for the purpose of illustrating the discrete-nucleon approach to spallation modeling and to exhibit differences between two versions of RENO. Comparisons with experimental, theoretical, and semiempirical data demonstrate the practicability of the discrete-nucleon approach.-

Ayres, C. L.↗
NASA NTRS1972

Photometry of compact galaxies.

Photometric histories of the N galaxies 3C 390.3 and PKS 0521-36. Four other compact galaxies, Markarian 9, I Zw 92, 2 Zw 136, and III Zw 77 showed no evidence of variability. The photometric histories were obtained from an exhaustive study of those plates of the Harvard collection taken with large aperture cameras. The images of all galaxies reported were indistinguishable from stars due to the camera f-ratios and low surface brightness of the outlying nebulosities of the galaxies. Standard techniques for the study of variable stars are therefore applicable.

Shen, B. S. P.↗
NASA NTRS1972

Accelerator measurement of the energy spectra of neutrons emitted in the interaction of 3-GeV protons with several elements

The application of time of flight techniques for determining the shapes of the energy spectra of neutrons between 20 and 400 MeV is discussed. The neutrons are emitted at 20, 34, and 90 degrees in the bombardment of targets by 3 GeV protons. The targets used are carbon, aluminum, cobalt, and platinum with cylindrical cross section. Targets being bombarded are located in the internal circulating beam of a particle accelerator.

Nalesnik, W. J.↗