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Biological Effects of Thermal Neutrons and the B10 (n,c) Li7 Reaction

Description: Boron-10 has a high thermal neutron capture cross section (3880 barns). Following neutron capture, the subsequent nuclear disintegration produces an alpha particle and a lithium-7 nucleus with the release of an average of 2.34 MeV for the particle irradiation, and in 93% of the reactions there is also the emission of an 0.48 MeV gamma ray: [equation not transcribed]. The kinetic energy is divided between the lithium-7 nucleus and the alpha particle giving the equal and opposite momentums with a… more
Date: January 13, 1964
Creator: Archambeau, J. O.; Alcober, V; Calvo, W. & Brenneis, H.
Item Type: Refine your search to only Report
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Dose-survival Curves for HeLa Cell Cultures Using Thermal Neutrons and the B10 (n,α)Li7 Reaction

Description: The biological evaluation of the thermal neutron capture reaction of boron-10, B10 (n,α)Li7 + 2.786 MeV, has previously been studied, using different particles from the boron-10 thermal neutron capture reaction compared with 250 kvp x-rays has been reported as 1.05 for spleen-thymic weight reduction (1), as 1.5 to 2.0 for skin lesions in pigs (2), and 1.87 for skin lesions of the rabbit's ear (3). The significance of such a calculation is felt to be unreliable for the boron-10 reaction in anima… more
Date: January 13, 1964
Creator: Archambeau, J. O.; Drew, R. M. & Robertson, J. S.
Item Type: Refine your search to only Report
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RBE of Monoenergetic Fast Neutrons: Cytogenetic Effects in Maize

Description: Investigations on the relative biological effectiveness (RBE) of densely ionizing radiations (with high LET, rate of linear energy transfer) are of importance in both fundamental and applied radiobiology. In the latter, they serve as a basis in setting permissible exposure levels for types of radiation about which little long range experience is available. Some of the best RBE studies have been done on chromosomal aberrations. The difficulty is determining RBE on the basis of chromosomal exchan… more
Date: November 13, 1963
Creator: Smith, H. H.; Bateman, J. L.; Quastler, H. & Rossi, H. H.
Item Type: Refine your search to only Report
open access

Reutilization of DNA-Thymine, and Conversion of RNA-Pyrimidines for DNA-Thymine, in Normal Rat Bone Marrow Studies with Tritiated Nucleosides

Description: If one injects into an animal H3-thymidine, 50% of it is incorporated into deoxyribonucleic acid (DNA), within approximately 30 to 45 minutes, while the rest is catabolized. A storage of H3-thymidine for later incorporation into DNA does not occur, on the basis of available evidence. Once incorporated, the label remains bound to DNA until cell death and no unequivocal evidence has as yet been presented to indicate metabolic renewal or intracellular turnover of the DNA molecule. The loss of labe… more
Date: November 13, 1963
Creator: Feinendegen, L. E.; Bond, V. P.; Cronkite, E. P. & Hughes, W. L.
Item Type: Refine your search to only Report
open access

Two Lectures on the Magnetic Scattering of Neutrons

Description: In these lectures we will discuss some examples of information about magnetic properties of solids which can be obtained by neutron scattering. We consider a scattering process in which a neutron with wave vector k and spin σ is incident upon a solid in state q>. (Here q stands for all of the quantum numbers which describe the state of the solid, such as spin and orbital electronic states, phonon numbers, etc.) After interacting with the solid, the neutron goes off with wave-vector k' and spin … more
Date: January 13, 1964
Creator: Blume, M.
Item Type: Refine your search to only Report
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The Use of Activated Charcoal Iodine Monitors During and Following a Release of Fission Product Iodines

Description: The present core of the Brookhaven Graphite Reactor consists of some 4900 highly enriched uranium fuel loaded in 615 horizontal fuel channels passing through a 25 foot cube of graphite moderator and reflector. The core is divided into two halves (north and south) by an 8 cm. wide vertical gap in the center of the graphite. The cooling air enters the reactor through inlet filters, at the rate of 270,000 CFM, passes into the central gap and flows bi-directionally through the north and south halve… more
Date: January 13, 1964
Creator: Foelix, Charles F. & Gemmell, L.
Item Type: Refine your search to only Report
open access

Use of Neutron Irradiations in the Brookhaven Mutations Program

Description: In brief, these facilities consist of a 250 KvP X-ray generator; two areas of a research reactor, one a well thermalized unit of moderate capacity and a larger area with a mixed thermal and fast neutron distribution, all of which are used for brief, acute exposure. A 10 acre field, currently with almost 4000 curies of cobalt 60, serves to irradiate entire plants for either short or long periods of time. Recently, the flux density of the thermal column was increased by a factor of 5 over the ori… more
Date: November 13, 1963
Creator: Miksche, J. P. & Shapiro, S.
Item Type: Refine your search to only Report
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