Experimental setup of Doppler broadening measurements in AGPAS. The electron beam is converted to a photon beam through the converter (con). The two collimators clean the photon-beam and determine its size. The ionization chamber measures the dose rate next to the converter. The NaI(Tl) detector monitors the photon-beam intensity behind the sample.
The dependence of the 511-keV count rate in AGPAS measurements on the sample thickness for aluminum and steel. No significant improvement in the count rate above 1.0-mm thickness.
The ratio of the 511-keV background with respect to the 511-keV photons from the sample in AGPAS measurements as a function of sample thickness for aluminum and steel. The 511-keV background is referred to the 511-keV yield from positron annihilation in air and other materials around the sample.
Relative parameter (Rel. parameter) as a function of tensile strain for steel alloy with 0.17 wt % C. The tensile test was performed at room temperature and the strain was measured for each sample during the tensile test. The last point on the graph represents the sample, which was loaded up to total failure.
Relative parameter (Rel. parameter) as a function of thickness reduction in cold work rolling at room temperature for steel alloy with 0.17 wt % C.
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