Reconstruction of momentum distribution from point-geometry positron-annihilation data

1979 ◽  
Vol 19 (2) ◽  
pp. 719-729 ◽  
Author(s):  
L. Pecora ◽  
A. C. Ehrlich
Keyword(s):  
Positron Annihilation ◽  
Momentum Distribution

MOMENTUM DISTRIBUTION OF METALLIC ELECTRONS BY POSITRON ANNIHILATION

1957 ◽  
Vol 35 (2) ◽  
pp. 168-183 ◽  
Author(s):  
A. T. Stewart
Keyword(s):  
Positron Annihilation ◽  
Momentum Distribution ◽  
Center Of Mass ◽  
Velocity Dependence ◽  
Conduction Electrons ◽  
Two Photon ◽  
Photon Decay ◽  
Electron Positron ◽  
Momentum Distributions ◽  
Annihilation Probability

The angular correlation of photons from the two-photon decay of positrons has been measured for positrons annihilating in some 34 elements, mostly metals. These data give the momentum distribution of photons and hence of the center of mass of the annihilating electron–positron pairs. The momentum distributions are discussed in terms of the velocity dependence of the annihilation probability. It is concluded that the observed momentum distributions are primarily the momentum distributions of the conduction electrons in the metals. A higher momentum component is observed, which is attributed to ion core effects.

Positron annihilation in alloys

1977 ◽  
Vol 55 (15) ◽  
pp. 1335-1341 ◽  
Author(s):  
K. M. Hong ◽  
J. P. Carbotte
Keyword(s):  
Positron Annihilation ◽  
Momentum Distribution ◽  
Coherent Potential Approximation ◽  
Fermi Momentum ◽  
Photon Momentum ◽  
Numerical Computations ◽  
Potential Approximation ◽  
Momentum Distributions ◽  
Annihilation Photon

A coherent potential approximation (CPA) treatment of positron annihilation in an alloy is presented. Simple formulae for the spatial and the momentum distributions of the positrons are derived. Numerical computations are performed to illustrate the effects of the smearing of the positron momentum distribution and of the electron Fermi momentum of the annihilation photon momentum distribution.

Pair momentum distribution inBi2Sr2CaCu2O8+δmeasured by positron annihilation: Existence and nature of the Fermi surface

1991 ◽  
Vol 67 (10) ◽  
pp. 1350-1353 ◽  
Author(s):  
L. P. Chan ◽  
D. R. Harshman ◽  
K. G. Lynn ◽  
S. Massidda ◽  
D. B. Mitzi
Keyword(s):  
Fermi Surface ◽  
Positron Annihilation ◽  
Momentum Distribution

Study of the electron momentum distribution in vanadium by positron annihilation

1983 ◽  
Vol 45 (9) ◽  
pp. 799-801 ◽  
Author(s):  
A.A Manuel ◽  
R Sachot ◽  
P Descouts ◽  
M Peter ◽  
R.M Singru ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Momentum Distribution ◽  
Electron Momentum ◽  
Electron Momentum Distribution

Positron Annihilation in Teflon and Polyethylene

1974 ◽  
Vol 52 (11) ◽  
pp. 935-939 ◽  
Author(s):  
Donald P. Kerr
Keyword(s):  
Angular Distribution ◽  
Positron Annihilation ◽  
Angular Correlation ◽  
Gamma Rays ◽  
Momentum Distribution ◽  
Angular Distributions ◽  
Distribution Data ◽  
Lifetime Component ◽  
Considerable Uncertainty ◽  
Correlation Data

Both the time spectra and the angular distributions of the annihilation gamma rays have been measured for positrons annihilating in Teflon and polyethylene in an attempt to clarify which annihilation mechanisms account for the various lifetimes in these materials. Some authors have suggested that, in addition to the longest lifetime component, one of the shorter lived components also arises from the pickoff annihilation of orthopositronium. If this were the case, substantially more positronium would be formed than is indicated by the intensity of the longest lived component alone, and should be detectable through a measurement of the intensity of the low momentum portion of the momentum distribution obtained from the angular correlation data. In the present work, four lifetimes are apparent in the time spectra although there is considerable uncertainty in resolving the two shortest components. The angular distribution data, in both cases, yielded a low momentum component whose intensity indicates that only the longest lifetime component arises from pickoff annihilation of orthopositronium. The three shorter lifetime components are discussed.

Sign in / Sign up

Export Citation Format

Share Document