Digital logarithmic airborne gamma ray spectrometer

Abstract

Abstract:A new digital logarithmic airborne gamma ray spectrometer is designed in this study. The spectrometer adopts a high-speed and high-accuracy logarithmic amplifier (LOG114) to amplify the pulse signal logarithmically and to improve the utilization of the ADC dynamic range, because the low-energy pulse signal has a larger gain than the high-energy pulse signal. The spectrometer can clearly distinguish the photopeaks at 239, 352, 583, and 609keV in the low-energy spectral sections after the energy calibration. The photopeak energy resolution of 137 Cs improves to 6.75% from the original 7.8%. Furthermore, the energy resolution of three photopeaks, namely, K, U, and Th, is maintained, and the overall stability of the energy spectrum is increased through potassium peak spectrum stabilization. Thus, effectively measuring energy from 20keV to 10MeV is possible.

Surface Engineering of Auxetic Scaffolds for Neural and Vascular Differentiation from Human Pluripotent Stem Cells

“…Auxetic PU (AU) foams were fabricated using previously developed processes. [29] In brief, the process involves isotropic compression of the starting materials followed by structure fixation. By careful selection of the starting materials and control of the fabrication conditions, different auxetic foams can be fabricated.…”

Ferroelectric‐Photocatalysts for Degradation of Phthalate: Doped BiFeO3‐Graphene Oxide Nanocomposites

“…A number of photocatalysts including TiO 2 , [ 12 ] ZnO, [ 13–15 ] Fe 2 O 3 , [ 16 ] MnFe 2 O 4 , [ 17 ] WO 3 , [ 18 ] and Bi 2 WO 6 , [ 19 ] and BiVO 4 [ 20 ] have been studied for their photodegradation efficiency against several phthalates and organic dyes. By using Bi 2 O 3 ‐TiO 2 it has been possible to degrade Cr(VI)/Pb(II)‐DBP mixed pollutants under visible light.…”