Digital triple coincidence positron lifetime setup with DRS4 and its benefits

2021 ◽  
Author(s):  
Martin Petriska ◽  
Stanislav Sojak ◽  
Vladimír Kršjak ◽  
Vladimír Slugeň
2000 ◽  
Vol 283-287 ◽  
pp. 858-862 ◽  
Author(s):  
H Ohkubo ◽  
S Sugiyama ◽  
K Fukuzato ◽  
M Takenaka ◽  
N Tsukuda ◽  
...  

2015 ◽  
Vol 213 (1) ◽  
pp. 165-169 ◽  
Author(s):  
Christian Herold ◽  
Hubert Ceeh ◽  
Thomas Gigl ◽  
Markus Reiner ◽  
Marco Haumann ◽  
...  

1993 ◽  
Vol 321 ◽  
Author(s):  
A. J. Kruk ◽  
H. Schut ◽  
J. Sietsma ◽  
A. Van Veen

ABSTRACTThe first stages of the nano-crystallization process of amorphous Fe75.5Cu1Nb3Si12.5B8 into a nano-crystalline structure are investigated by the positron annihilation lifetime technique. Samples have been isothermally annealed at 643 K for times varying between 600 and 105 seconds. The positron lifetime spectra have been analyzed allowing for three lifetimes. The shortest and the longest lifetime, τ1 = 150 ± 2 ps and τ3 = 1500–2000 ps respectively, are attributed to annihilation of positrons in the amorphous phase and to the formation and annihilation of ortho-positronium at the surface of the stacked foils and did not change significantly upon the annealing. The intermediate positron lifetime τ2 increased from 324 ps to 387 ps. The intensity of this component increased from 5 to 15%. Comparison with resistivity measurements indicates that the change of this lifetime component occurs at an early stage in the crystallisation process, i.e. when the fraction of crystalline material is on the order of 10−3. The increase of τ2 is attributed to positrons annihilating in a region with lower average density surrounding the small crystallite.


1995 ◽  
Vol 60 (6) ◽  
pp. 541-544 ◽  
Author(s):  
A. Polity ◽  
Th. Abgarjan ◽  
R. Krause-Rehberg

1971 ◽  
Vol 4 (2) ◽  
pp. 261-268 ◽  
Author(s):  
K P Singh ◽  
R M Singru ◽  
C N R Rao

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Abdullah Mohammed Ali Mohammed Altaweel ◽  
Jaya Madhu Raj ◽  
Malalvalli Nagarajaiah Chandrashekara ◽  
Puttegowda Ramya ◽  
Parthasarathy Sampathkumaran ◽  
...  

Abstract Polystyrene (PS) based composites respectively with cenosphere (CS) and calcium aluminosilicate (CAS) as fillers were studied using the positron lifetime technique to reveal the correlation between free volume, a microstructural property, and mechanical properties of the composites (tensile strength and tensile modulus). The thermal stability of the composites was determined using differential scanning calorimetry. The results showed that addition of CAS filler lead to a significant improvement in the mechanical properties of the composite, whereas addition of CS resulted in improvement in tensile modulus only. Both PS/CAS and PS/CS composites showed enhancement in thermal stability compared with that of the pure PS matrix. The positron results showed that the average free volume size for the PS/CAS composite (at 40 phr CAS) was reduced significantly compared with that of the pure PS. These results are understood in terms of the influence of silica content, filler-matrix interaction, and particle size.


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