1,721,104 research outputs found
Characterisation of a radionuclide specific laboratory detector system for the metallurgical industry by Monte Carlo simulations
No full textOne of the outputs of the European Metrology Research Programme project "Ionising radiation metrology for the metallurgical industry" (MetroMetal) was a recommendation on a novel radionuclide specific detector system optimised for the measurement of radioactivity in metallurgical samples. The detection efficiency of the recommended system for the standards of cast steel, slag and fume dust developed within the project was characterized by Monte Carlo (MC) simulations performed using different MC codes. Capabilities of MC codes were also tested for simulation of true coincidence summing (TCS) effects for several radionuclides of interest in the metallurgical industry. The TCS correction factors reached up to 32% showing that the TCS effects are of high importance in close measurement geometries met in routine analyses of metallurgical samples. © 2015 Elsevier Ltd
A full digital approach to the TDCR method
No full textCurrent state of the art solutions based on the Triple to Double Coincidence Ratio method are generally large size, heavy-weight and not transportable systems. This is due, on one side, to large detectors and scintillation chambers and, on the other, to bulky analog electronics for data acquisition. CAEN developed a new, full digital approach to TDCR technique based on a portable, stand-alone, high-speed multichannel digitizer, on-board Digital Pulse Processing and dedicated DAQ software that emulates the well-known MAC3 analog board. © 2013 Elsevier Ltd
Equivalence of computer codes for calculation of coincidence summing correction factors
No full textThe aim of the study was to check for equivalence of computer codes that can perform calculations of true coincidence summing correction factors. All calculations were performed for a set of well-defined detector and sample parameters, without any reference to empirical data. For a p-type detector model the application of different codes resulted in satisfactory agreement in the calculated correction factors. For high-efficiency geometries in combination with an n-type detector and a radionuclide emitting abundant X-rays the results were scattered. © 2013 Elsevier Ltd
Production status of the JLAB Hall-A GEM and Si μstrip Tracker
No full textWe developed and tested a new charged particle tracking system, able to operate in high luminosity experiments, which will be installed at Jefferson Laboratory HallA (VA, USA) for optimally exploit the new 12 GeV energy electron beam available at the end of 2013. The tracker is made of six GEM (Gas Electron Multiplier) large chambers and two 10×20 cm2 planes of SIlicon microstrip Detectors (SIDs). Each GEM chamber is composed by three 40×50 cm2 GEM modules, with two-dimensional strip readout, with expected spatial resolution of about 70 mm. The same dedicated acquisition system will be used for both detectors (GEM & SID) for a grand total of more than 50,000 channels. The readout electronics is divided into two parts: the front-end cards (based on the existing APV25 chip), hosted on the detectors periphery and the digitizer, a multi purpose VME-64x/VXS board located far from the high radiation environment. The very same electronics has been adopted by the Olympus experiment (DESY, Hamburg, D) to read out the six GEM chambers of its luminosity monitor. The developed detectors and electronics are now ready for the production, which will last for the next 2 years. © 2012 Elsevier B.V. All rights reserved
Bilateral comparison between PTB and ENEA to check the performance of a commercial TDCR system for activity measurements
No full textThe only commercial TDCR counter from Hidex Oy (Finland), comprising three photomultiplier tubes, was tested at the two National Metrology Institutes (NMIs) PTB and ENEA. To this end, the two NMIs purchased a Hidex 300 SL TDCR counter (METRO version) each and carried out various tests at their laboratories. In addition, the two institutions agreed to organize a bilateral comparison in order to acquire information on the reproducibility of the results obtained with the counters. To achieve this, PTB prepared some 89Sr liquid scintillation samples, which were first measured in various counters at PTB and then shipped to ENEA for comparative measurements. The aim of this paper is to summarize the findings on the counter characteristics and adjustments. In addition, the results of the bilateral comparison between PTB and ENEA are presented and the results from various commercial counters using the CIEMAT/NIST efficiency tracing and the TDCR method are discussed. © 2014 Elsevier Ltd
Construction and implementation of a TDCR system at ENEA
No full textA new 4π (LS) TDCR system was built at ENEA-INMRI. Three photomultiplier tubes, arranged in a planar 120° geometry around a spherical optical chamber, were directly linked to a CAEN Desktop Digitizer DT5720. This module, based on the Field Programmable Gate Array (FPGA) technology for real time Digital Pulse Processing (DPP), allowed to replace all the classical TDCR electronics by only one device. The activity of 3H and 63Ni standard sources were successfully measured by the new detector. © 2013 Elsevier Ltd
Metrological issues in molecular radiotherapy
No full textThe therapeutic effect from molecular radiation therapy (MRT), on both tumour and normal tissue, is determined by the radiation absorbed dose. Recent research indicates that as a consequence of biological variation across patients the absorbed dose can vary, for the same administered activity, by as much as two orders of magnitude. The international collaborative EURAMET-EMRP project "Metrology for molecular radiotherapy (MetroMRT)" is addressing this problem. The overall aim of the project is to develop methods of calibrating and verifying clinical dosimetry in MRT. In the present paper an overview of the metrological issues in molecular radiotherapy is provided. © Owned by the authors, published by EDP Sciences, 2014
Recent advances in digital coincidence counting for Radionuclide Metrology
No full textThe radioactivity measurement techniques developed within the EURAMET EMRP 'MetroFission' Joint Research Project, were aimed at performing on-site activity measurements at the primary standard level (4πβ-γ coincidence counting) for a wide range of radionuclides utilizing recent advances in high-speed digital sampling and digital signal processing. The state-of-the-art technology employed within this project provides up to 14-bit digitizer systems operating with sampling rates in the order of 108 to 109 samples-per-second, incorporating on-board FPGA devices, which greatly enhances the application of digital signal processing for the implementation of digital coincidence counting. These devices when coupled to suitable analysis software, demonstrate a significant improvement in the provision of primary standards of radioactivity. This manuscript provides a description of the systems employed, along with recommendations regarding optimization of the digital sampling of signals from photo-multiplier tubes and pre-amplifiers and compare the benefits of 'off-line' versus 'on-line' 4πβ-γ digital coincidence counting systems. © 2013 IEEE
A prototype of a portable TDCR system at ENEA
No full textA prototype of a portable liquid scintillation counting system based on the Triple-to-Double Coincidence Ratio (TDCR) technique was developed at ENEA-INMRI in the framework of the European Metrofission project. The new device equipped with the CAEN digitizers was tested for the activity measurements of pure ?-emitters (99Tc and 63Ni). The list-mode data recorded by the digitizers were analyzed by software implemented in the CERN ROOT environment, which allows the application of pulse shape discrimination using the new device. ᄅ 2014 Elsevier Ltd
Development of portable Liquid Scintillation counters for on-site primary measurement of radionuclides using the Triple-To-Double Coincidence Ratio method
No full textThe Triple-to-Double Coincidence Ratio (TDCR) method in Liquid Scintillation counting (LSC) is a primary radionuclide standardization method widely used in National Metrology laboratories and was primarily developed for the activity measurement of beta emitters. It is based on liquid scintillation: the light is detected by three photomultipliers (PM) and the detection efficiency is evaluated by using a model which uses the ratio of triple-to-double coincidences between the PM tubes. © 2013 IEEE
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