Orientation of nucleus excited in annihilation of positron on heavy-atom shell. [0. 5 to 6. 55 MeV]

Journal Article · Thu Feb 01 00:00:00 EST 1979 · Sov. Phys. - JETP (Engl. Transl.); (United States)

OSTI ID:5827430

Grechukhin, D P; Soldatov, A A

A calculation is made of the cross sections and orientation spin tensors of a nucleus excited in nonradiative annihilation of a positron by an electron from an (nlj) shell of an atom. Use is made of relativistic wave functions of the electron and positron, obtained by numerical integration of the Dirac equation with a single average Hartree--Fock--Slater atomic potential. The results of calculations of the factors governing the cross sections and orientation of the excited nucleus as a function of the positron energy E/sub +/ = 0.5--6.55 MeV are presented graphically for the series of E0, E1, and M1 multipole transitions in annihilation on the K shell of an atom. The results are given for the atoms with Z=41,49,60,70,82, and 92. Estimates are also obtained for the annihilation of a positron on the L shell of lead (Z=82). The results are used to estimate the cross sections of nuclear excitation in positron annihilation and the angular distributions of the decay products (quanta, fission fragments, etc.) of a nucleus excited in this way. A brief discussion is made of possible applications of low-energy positron beams in nuclear spectroscopy.

• Research Organization: I. V. Kurchatov Institute of Atomic Energy, Academy of Sciences of the USSR, Moscow
• OSTI ID: 5827430
• Journal Information: Sov. Phys. - JETP (Engl. Transl.); (United States), Vol. 49:2
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
INDIUM
POSITRON REACTIONS
POSITRON-ATOM COLLISIONS
LEAD
NEODYMIUM
NIOBIUM
ANNIHILATION
NUCLEAR ALIGNMENT
URANIUM
YTTERBIUM
ANGULAR DISTRIBUTION
CROSS SECTIONS
DIRAC EQUATION
ENERGY-LEVEL TRANSITIONS
EXCITATION
HARTREE-FOCK METHOD
K SHELL
L SHELL
SLATER METHOD
SPIN ORIENTATION
WAVE FUNCTIONS
ACTINIDES
ATOM COLLISIONS
BASIC INTERACTIONS
COLLISIONS
DIFFERENTIAL EQUATIONS
DISTRIBUTION
ELECTROMAGNETIC INTERACTIONS
ELECTRONIC STRUCTURE
ELEMENTS
EQUATIONS
FUNCTIONS
INTERACTIONS
LEPTON REACTIONS
METALS
NUCLEAR REACTIONS
ORIENTATION
POSITRON COLLISIONS
RARE EARTHS
REFRACTORY METALS
TRANSITION ELEMENTS
WAVE EQUATIONS
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