324 research outputs found
Annual Report on Contract AEC AT(11-1) 34 p107B
Work that has been carried out in several areas of High Energy Physics is described. Visual techniques are used. For the study of the three-pion decay of the K/sup +/ meson, bubble chamber and emulsion methods are used to complement each other, particularly for the tau' mode. Several separate bubble chamber experiments in ..pi../sup +/p, anti pp and K/sup -/p interactions are also described, and the large effort devoted to computer reprogramming for the data analysis indicated. Two emulsion research projects are also described which have for their purpose the study of electromagnetic processes induced by 16 BeV electrons and the study of hypernuclei by K/sup -/ mesons. For the latter work high speed computer methods have been successfully applied to the analysis of the product hypernuclei. These programs of work have not been under way long enough for the main results yet to be available, but some preliminary data have been published and several reports on data analysis and related subjects have been prepared
Physics of ion beam cancer therapy: a multi-scale approach
We propose a multi-scale approach to understand the physics related to
ion-beam cancer therapy. It allows the calculation of the probability of DNA
damage as a result of irradiation of tissues with energetic ions, up to 430
MeV/u. This approach covers different scales, starting from the large scale,
defined by the ion stopping, followed by a smaller scale, defined by secondary
electrons and radicals, and ending with the shortest scale, defined by
interactions of secondaries with the DNA. We present calculations of the
probabilities of single and double strand breaks of DNA, suggest a way to
further expand such calculations, and also make some estimates for glial cells
exposed to radiation.Comment: 18 pag,5 fig, submitted to PR
Data for Elementary-Particle Physics
These data are provided: Masses and .Mean Lives of Elementary Particles; Atomic and Nuclear Properties of Materials; Particle Scattering; Atomic and Nuclear Constants; Particle Decay and Reaction Dynamics; Tentative Data on Strongly lnteracting Particles and Resonances; and Clebsch-Gordan Coefficients and Spherical Harmonics
Nonlinear energy-loss straggling of protons and antiprotons in an electron gas
The electronic energy-loss straggling of protons and antiprotons moving at
arbitrary nonrelativistic velocities in a homogeneous electron gas are
evaluated within a quadratic response theory and the random-phase approximation
(RPA). These results show that at low and intermediate velocities quadratic
corrections reduce significantly the energy-loss straggling of antiprotons,
these corrections being, at low-velocities, more important than in the
evaluation of the stopping power.Comment: 4 pages, 3 figures, to appear in Phys. Rev.
Comparative reproduction of the female horse, elephant and rhinoceros: implications for advancing assisted reproductive technologies
Recent loss of rhinoceros subspecies has renewed interest in using more advanced assisted reproductive technologies (ART) in rhinoceroses and elephants. Currently, only semen collection, semen preservation and artificial insemination (AI) have been used repeatedly with success in these species. Although ovum pick-up (OPU) and intra-cytoplasmic sperm injection (ICSI) have been reported recently in rhinoceroses, the techniques are not yet optimised. In contrast, multiple ART applications are routinely used in the horse. Since elephants and rhinoceroses share some reproductive features with equids, we postulate that procedures such as OPU, ICSI, in vitro fertilisation (IVF) and embryo transfer (ET), which are well established in the horse, may represent a basis to develop protocols for endangered pachyderms. In this review, we summarise current knowledge on reproductive physiology relevant to ART. We discuss the current state of ART in all three families and the requirements for the successful implementation of OPU, ICSI, IVF and ET in these species
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The Antiproton-Nucleon Annihilation Process (AntiprotonCollaboration Experiment)
In the exposure to a 7 0 0-MeV/c negative particle beam, 35 antiproton stars have been found. Of these antiprotons, 21 annihilate in flight and three give large-angle scatters ( {Theta} > 15 , T{sub P-} > 50 Mev), while 14 annihilate at rest. From the interactions in flight we obtain the total c r o s s section for antiproton interactio
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