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The 53 Mn flux onto Earth is a quantity relevant for different extraterrestrial and astrophysical questions. It is a proxy for related fluxes, such as supernova-produced material or interplanetary dust particles. In this work, we performed a first attempt to assess the 53 Mn flux by measuring the 53 Mn/ 10 Be isotopic ratio in a 1400 L sample of molten Antarctic snow by AMS (Accelerator Mass Spectrometry). Using the 10 Be production rate in the atmosphere, an upper limit of 5.5 × 10 3 atoms cm -2 yr -1 was estimated for the deposition of extraterrestrial 53 Mn. This result is compatible with one of the two discrepant values existing in the literature., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A 4πγ integral counting system with a NaI(Tl) well-type detector and a digital interface to acquire measurement data was implemented at LMR-CNEA. The detection efficiency as a function of the energy was computed by Monte Carlo simulations and the total efficiencies for ampoules and point sources were calculated considering all the decay branches. A computer code was developed to analyse data. This program reads the files generated by the digitizer module, corrects for dead time and calculates source activities and their uncertainties. Ampoules with solutions of 113 Sn, 192 Ir and 131 I were measured., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The radionuclide (68)Ga is one of the few positron emitters that can be prepared in-house without the use of a cyclotron. It disintegrates to the ground state of (68)Zn partially by positron emission (89.1%) with a maximum energy of 1899.1 keV, and partially by electron capture (10.9%). This nuclide has been standardized in the frame of a cooperation project between the Radionuclide Metrology laboratories from CIEMAT (Spain) and CNEA (Argentina). Measurements involved several techniques: 4πβ-γ coincidences, integral gamma counting and Liquid Scintillation Counting using the triple to double coincidence ratio and the CIEMAT/NIST methods. Given the short half-life of the radionuclide assayed, a direct comparison between results from both laboratories was excluded and a comparison of experimental efficiencies of similar NaI detectors was used instead., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The nuclide (241)Am decays by alpha emission to (237)Np. Most of the decays (84.6%) populate the excited level of (237)Np with energy of 59.54 keV. Digital coincidence counting was applied to standardize a solution of (241)Am by alpha-gamma coincidence counting with efficiency extrapolation. Electronic discrimination was implemented with a pressurized proportional counter and the results were compared with two other independent techniques: Liquid scintillation counting using the logical sum of double coincidences in a TDCR array and defined solid angle counting taking into account activity inhomogeneity in the active deposit. The results show consistency between the three methods within a limit of a 0.3%. An ampoule of this solution will be sent to the International Reference System (SIR) during 2009. Uncertainties were analysed and compared in detail for the three applied methods., (Copyright 2009 Elsevier Ltd. All rights reserved.)

A non-radionuclide-specific computer code to analyze data, calculate detection efficiency and activity in a TDCR system is presented. The program was developed prioritizing flexibility in measuring conditions, parameters and calculation models. It is also intended to be well structured in order to easily replace subroutines which could eventually be improved by the user. It is written in standard FORTRAN language but a graphical interface is also available. Several tests were performed to check the ability of the code to deal with different decay schemes such as H-3, C-14, Fe-55, Mn-54 and Co-60.