8,347 research outputs found
Radiative capture of polarized neutrons by polarized protons
A model-independent irreducible tensor approach to p(n,gamma)d is presented
and an explicit form for the spin-structure of the matrix for the reaction is
obtained in terms of the Pauli spin-matrices for the neutron and the proton.
Expressing the multipole amplitudes in terms of the triplet --> triplet and
singlet --> triplet transitions, we point out how the initial singlet and
triplet contributions to the differential cross section can be determined
empirically.Comment: Revised version; typeset using RevTeX4; 6 pages, no figure
Phase ambiguity of the threshold amplitude in pp -> pp\pi^0
Measurements of spin observables in pp -> {\vec p}{\vec p}\pi^0 are suggested
to remove the phase ambiguity of the threshold amplitude. The suggested
measurements complement the IUCF data on {\vec p}{\vec p} -> pp\pi^0 to
completely determine all the twelve partial wave amplitudes, taken into
consideration by Mayer et.al. [15] and Deepak, Haidenbauer and Hanhart [20].Comment: 4 pages, 1 table
Deuteron photodisintegration with polarized photons at astrophysical energies
Following precise experimental studies at the Duke Free-Electron Laser
Laboratory, we discuss photodisintegration of deuterons with 100% linearly
polarized photons using a model independent theoretical approach taking
together and amplitudes simultaneously. The isoscalar
contribution is also taken exactly into account. From the existing experimental
measurement on doubly polarized thermal neutron capture, it is seen that the
isoscalar contribution could be of the same order of magnitude as the
experimentally measured cross sections at energies relevant to Big Bang
Nucleosynthesis (BBN). Therefore appropriate measurements on deuteron
photodisintegration are suggested to empirically determine the
contribution at astrophysical energies.Comment: 5 Pages, Latex-2
Electrolysis of Fused Anhydrous Aluminium Chloride and Chlorination of Salem Bauxite
Investigations carried out to determine (i)optimum condit-ions for the electrolysis of fused anhydrous aluminium chloride to yield aluminium metal and (ii) the optimum conditions for the chlorination of the ferruginous bauxite-ores from Salem District so as to eliminate selectively the chief impurities associated with these and to yield an acceptable grade of bauxite, are described. The electro-lysis experiments were carried out using chemically pure salts, to obtain reliable working results. Chlorination experiments yielded encouraging results if carried out on a mixture of the bauxite and powdered charcoal and on initially sulphided bauxite
Fluctuations of light intensity in coron Æ formed by diffraction
The fluctuations of light intensity in the diffraction corona produced by a large number of randomly distributed particles are investigated both theoretically and experimentally. The theoretical considerations show that the view put forward by de Haas is inadequate and that really the fluctuations arise owing to the interference of the waves diffracted by all the particles, which gives rise to a large number of sharp images of the source in monochromatic light. In white light, these spots must spread out, and produce radial streaks. These deductions from theory are all borne out by experiment
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