Free-Positron Annihilation Mean Life in Diatomic and Rare Gases in Liquid and Solid States

1963 ◽  
Vol 132 (4) ◽  
pp. 1633-1635 ◽  
Author(s):  
D. C. Liu ◽  
W. K. Roberts
Keyword(s):  
Positron Annihilation ◽  
Rare Gases ◽  
Solid States ◽  
Free Positron

Positron annihilation in low-temperature rare gases. I. Helium

1975 ◽  
Vol 12 (2) ◽  
pp. 375-385 ◽  
Author(s):  
K. F. Canter ◽  
J. D. McNutt ◽  
L. O. Roellig
Keyword(s):  
Low Temperature ◽  
Positron Annihilation ◽  
Rare Gases

Positron annihilation in methane gas

1970 ◽  
Vol 48 (24) ◽  
pp. 2984-2990 ◽  
Author(s):  
P. M. Smith ◽  
D. A. L. Paul
Keyword(s):  
Positron Annihilation ◽  
Standard Error ◽  
Room Temperature ◽  
Annihilation Rate ◽  
Effective Number ◽  
Gas Density ◽  
Methane Gas ◽  
Free Positron

The annihilation of positrons in methane gas at room temperature has been measured at pressures below 2 atm. The annihilation rate for the free positron component is proportional to the gas density and corresponds to an effective number of electrons per molecule taking part in annihilation, Zeff = 139.6 ± 1.0 (standard error). The quenching of orthopositronium corresponds to 1Zeff = 0.57 ± 0.07. Resonance annihilation is discussed in a general way.

Dispersion de réfraction de l'argon, du krypton et du xénon sous les états solide et liquide

1970 ◽  
Vol 48 (17) ◽  
pp. 1947-1948 ◽  
Author(s):  
Jules Marcoux
Keyword(s):  
Visible Region ◽  
Index Of Refraction ◽  
Rare Gases ◽  
Solid States ◽  
Graph Form

Variations of the index of refraction, in the visible region, for three rare gases, argon, krypton, and xenon, in the liquid and solid states have been measured. The measured values are given in table and graph form. The value of n∞ for solid xenon is determined.

Time of flight spectrometer for background-free positron annihilation induced Auger electron spectroscopy

2016 ◽  
Vol 87 (3) ◽  
pp. 035114 ◽  
Author(s):  
S. Mukherjee ◽  
K. Shastry ◽  
C. V. Anto ◽  
P. V. Joglekar ◽  
M. P. Nadesalingam ◽  
...  
Keyword(s):  
Auger Electron Spectroscopy ◽  
Positron Annihilation ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Time Of Flight ◽  
Free Positron

Effective electron density for free-positron annihilation in low-Z compounds

1967 ◽  
Vol 50 (2) ◽  
pp. 256-262 ◽  
Author(s):  
C. Bussolati ◽  
S. Cova ◽  
L. Zappa
Keyword(s):  
Positron Annihilation ◽  
Electron Density ◽  
Effective Electron ◽  
Free Positron

scholarly journals Analytical Studying of Positron Annihilation Equations: دراسة تحليليّة لمعادلات الفناء البوزيتروني

2019 ◽  
Vol 3 (4) ◽  
Author(s):  
Huda Abd- Al Mohaimen Al Droubi, Abd Al Hadi Mostafa Soufan,
Keyword(s):  
Positron Annihilation ◽  
Life Time ◽  
Positronium Formation ◽  
Second Stage ◽  
The Third ◽  
Third Phase ◽  
Positronium Annihilation ◽  
Different Types ◽  
Free Positron ◽  
The Moment

  In this study examined the changes in some materials by studying different types of positron annihilations, such as free annihilation, bound annihilation, para and ortho positronium annihilation, and found that the o- Ps annihilation passes through a free- annihilation stage called the "pick- off" annihilation. Also solved the equations of the positron annihilation in two ways, computationally and programmatically (using the scilab- 6.0.1 and Mathematica12) according to specific conditions, at the moment t= 0, positronium was not yet formed, In the first stage studied the free positron annihilation, in the second stage the annihilation of the p- Ps and in the third phase, the annihilation of the o- Ps was studied, and we have found that the coefficient of decrease in the number of free positrons  at the same time reflects the probability of positronium formation. Studied the spectrum of the positron and positronium in both para and ortho and determine the positron case by solving the annihilation equations under different conditions and according to the life time of each case, this requires the study of the annihilation spectra of different materials to take advantage of this in the detection of defects in the material and improve the structure.    

Positron Annihilation Lifetime of Irradiated Polyimide

2012 ◽  
Vol 733 ◽  
pp. 151-154 ◽  
Author(s):  
Tetsuya Hirade ◽  
Toshitaka Oka ◽  
Norio Morishita ◽  
Akira Idesaki ◽  
Akihiko Shimada
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Volume Change ◽  
Electron Beam Irradiation ◽  
Positron Lifetime ◽  
Irradiation Effect ◽  
Beam Irradiation ◽  
Positron Annihilation Lifetime ◽  
Free Positron ◽  
Annihilation Probability

Ortho-positronium pick off annihilation lifetime gives the information of the microscopic free volume of polymers. Polyimide polymers such as Kapton are applied in many fields, but it was impossible to apply the positron lifetime method for free volume investigation because of no positronium formation. Here, we apply the idea of the free positron annihilation probability that is sum of the probability of annihilation by the positron and electrons on the molecular chain where the positron localized and that for the annihilation with the electrons on the neighboring molecular chains. The second term is probably affected by the free volume change. We have successfully shown the temperature dependence and the electron beam irradiation effect on the free volume change by observing the free positron annihilation lifetime for Kapton.

Positron annihilation in low-temperature rare gases. II. Argon and neon

1975 ◽  
Vol 12 (2) ◽  
pp. 386-395 ◽  
Author(s):  
K. F. Canter ◽  
L. O. Roellig
Keyword(s):  
Low Temperature ◽  
Positron Annihilation ◽  
Rare Gases
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