Abstract
Positron is the antipartie le of electron and its existence was predicted “by Dirac’s relativistic theory of electron. Positrons were experimentally discovered “by Anderson in cloud chamber photographs of cosmic rays. In a material medium, positrons do not live long because they can either annihilate with electrons in the medium, or can form a metastahle system of a positronium atom which is short-lived. In the first type of decay, called prompt or free annihilation, a positron, after thermalisation, annihilates with an electron in “the medium either througji a singlet collision (spins antiparallel) or through a triplet collision (spins parallel). Selection rules governing the annihilation show that a singlet collision results in emission of two photons in exactly opposite direction and each one having an energv of about 511 (= m0 c2) KeV. This annihilation has a life time ~10-10 s. On the other hand, a triplet collision gives rise to an annihilation into three photons with a lifetime ~10-7 secs. In this case the total rest energy (= 2 m0 c2) of the electron-positron pair is shared between the three photons which are emitted in one plane. The ratio of singlet (2 photon) to triplet (3-photon) annihilation rates was calculated by Ore and Powell2 to “be
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References
M. Deutsch, Progr. Hmc. Phys., 3, 131 (1953).
A. Ore and J.L. Powell, Phys. Rev., 75, 1696 (1949).
R.A. Ferrell, Rev. Mod. Phys., 28, 308 (1956).
A.T. Stewart, Canad. J. Phys., 35, 168 (1957).
L.G. Lang and S. DeBenedetti, Phys. Rev., 108, 914 (1957).
A.T. Stewart, in “Positron Annihilation”, edited by A.T. Stewart and L.O. Roellig, Academic Press, New York, 1967.
C.K. Majumdar, in “Theory of Condensed Matter”, International Atomic Energy Agency, Vienna, 1968.
I. Ya. Dekhtyar, Czech. J. Phys., 18B, 1 (1968).
A. Ore, Univ. i Bergen latarvit, rekke 9 (1949).
A.Z. Schwarzschild and E.K. Warhmrton, Ann. Rev. Nmclear Sci., 18, 265 (1968).
G.J. Celitans, S.J. Tao and J.H. Green, Proc. Phys. Soc. (London), 85, 833 (1964).
J.H. Green, in “Positron Annihilation”, edited by A.T. Stewart and L.O. Roellig, Académie Press, New York, 1967.
S.J. Tao, J.H. Green and G.J. Celitans, Proo. Phys. Soc. (London), 81, 1091 (1963).
J.H. Green and S.J. Tao, J. Chem. Phys., 39, 3160 (1953).
C.Y. Leung and D.A.L. Paul, J. Phys. (Lond.), B 2, 1278 (1969).
H.S.W. Massey, in “Positron Annihilation” edited by A.T. Stewart and L.O. Roellig, Academic Press, Hew York, 1967•
W. Brandt and H. Peibus, Phys. Rev., 184, 277 (1969).
H. Weisberg and S. Berko, Phys. Rev., 154. 249 (1967).
S. Kahana, Phys. Rev., 129, 1622 (1963).
A. Gianotti, C. Ghessi and M. Manbredi, Nuovo Cimento, 62 B. 121 (1969)-
P. Sen and A.P. Patro, Phys. Lett., 28 A, 414(1963).
Y.I. Goldanskii and E.P. Prokop’ev, Sov. Phys. Solid State, 6, 2641 (1964).
C. Bussolati, A. Dapasquier and L. Zappa, Muovo Cimento, 52 B, 529 (1967).
K.P. Singh, R.M. Singru and C.N.R. Rao, Chem. Phys. Letts., 3, 247 (1969).
H.F. Waung, W. Brandt and P.W. Levy, Bull. Am. Phys. Soc., 13, 1473 (1968).
J.L. Williams and H.J. Ache, J. Chem. Phys., 31A, 3536 (1969).
D. Her lach and F. Heinrich, Phys. Letts., 31 A, 47 (1970).
K.P. Singh, R.M. Singru, M.S. Tomar and C.N.R. Rao (To be published).
P. Colombino and B. Piscella, Nuovo Cimento, 58 B, 413 (1968).
B.V. Thosar, V.G. Kulkarni, R.G. Lagu and G. Chandra, Phys. Letts., 28 A, 760 (1969).
W. Brandt, in “Positron Annihilation”, edited by A.T. Stewart and L.O. Boellig, Academic Press, New York, 1967.
P.E. Gray, CF. Cook and G.P. Strain, Jr., J. Chem. Phys., 48. 145 (1968).
K.P. Singh, R.M. Singru and C.N.R. Rao (To be published).
G. Chandra, V.G. Kmlkarni, E.G. Lagu and B.V. Thosar, Phys. Letts., 19, 201 (1965).
B.V. Thosar, V.G. Kulkarni, E.G. Lagu and G. Chandra, Phys. Letts., 21, 647 (1966).
T.I. Goldanskii, in “Positron Annihilation”, edited by A.T. Stewart and L.O. Boellig, Academic Press, New York, 1967.
S.J. Tao and J.H. Green, J. Chem. Soc. A., 408 (1968).
J.H. Green and J. Lee, “Positronium Chemistry”, Academic Press, New York, 1964.
J.B. McGervey, in “Positron Annihilation”, edited by A.T. Stewart and L.O. Boellig, Academic Press, New York, 1967.
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Singru, R.M. (1970). Positron Annihilation in Solids. In: Rao, C.N.R. (eds) Modern Aspects of Solid State Chemistry. Springer, Boston, MA. https://doi.org/10.1007/978-1-4684-1875-0_12
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DOI: https://doi.org/10.1007/978-1-4684-1875-0_12
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