95 research outputs found
Treatment of radioactively contaminated wastewater in nuclear medicine facilities
No full textDiese Arbeit basiert auf einer Literaturrecherche und beschäftigt sich mit dem Abwasser aus nuklearmedizinischen Einrichtungen. Werden Patienten radioaktive Substanzen verabreicht, verweilen diese für eine gewisse Zeit im Körper und werden dann über die Atemluft sowie Körperflüssigkeiten und Exkremente ausgeschieden. Abhängig von den physikalischen Eigenschaften der inkorporierten Stoffe, ist die Höhe der potenziellen Gefahr, die von diesen Ausscheidungen ausgeht. Um das Personal dieser Einrichtungen sowie die Allgemeinbevölkerung vor gesundheitlichen Schäden durch Strahlung zu schützen, gibt es strenge Vorschriften und Grenzwerte, die bei der Ableitung des Abwassers ins Kanalsystem einzuhalten sind. Nach heutigem Stand der Technik, wird das Abwasser aus den Therapiestationen in speziellen Tanks zwischengelagert, diese werden als Abklinganlagen bezeichnet. In diesen Behältern wird das Abwasser gelagert, bis die Radioaktivität unter den behördlich festgelegten Grenzwert fällt und sicher abgeleitet werden kann.
Die Arbeit gibt einen Überblick, welche grundlegenden Überlegungen in die Planung von Abklinganlagen einfließen müssen, von den Anforderungen an die Nasszellen der Patientenzimmer bis hin zur Entleerung ins kommunale Kanalsystem. Abschließend stellt die Autorin neue Ansätze zur Abwasserbehandlung vor, welche das Potential haben in Zukunft die herkömmlichen Abklinganlagen zu ersetzen.This thesis is based on a literature research and deals with wastewater from nuclear medicine facilities. If patients are treated with radiopharmaceuticals, they stay in the body for a certain period and are then excreted via the respiratory air as well as body fluids and feces. The potential hazard of this excretion is depending on the physical properties of the incorporated substances. In order to protect the personnel of these facilities as well as the general population against health damage caused by radiation, there are strict regulations and thresholds to comply with when discharging the wastewater into the sewer system. According to the current state of the art, the wastewater from the therapy stations is stored in special containers, known as decay tanks. Their function is to store the liquid waste until its activity drops below a threshold determined by the authority, before it can be safely released into the sewer system.
The work gives an overview of the basic considerations that must be taken into account in the planning process of decay systems, from the requirements of the wet rooms of the patient rooms to the discharge into the municipal canal system. Finally, the author presents new approaches to wastewater treatment, which have the potential to replace conventional decay systems in the future
Implementation of the VMM ASIC in the Scalable Readout System
No full textThe Scalable Readout System (SRS) developed by the RD51 collaboration is a versatile and multi-purpose approach, which is used with different front-end chips to transfer data from detectors to computers. Targeting mainly micro-pattern gaseous detectors, the system is also applicable for silicon strip or pad detectors. The most frequently used front-end chip today is the APV25, originally developed for the CMS pixel detector. In the scope of the ATLAS New Small Wheel upgrade, a new front-end chip, the VMM, is developed, which has significantly improved specifications compared to the APV25.
We report on the implementation of the VMM in the Scalable Readout System carried out by the RD51 collaboration in the framework of a detector project related to the European Spallation Source ERIC. Due to the hierarchical design of the Scalable Readout System, only specific parts of the readout chain need to be adapted or designed, which is the carrier board for the front-end chip, an adapter card that connects to the common hardware of the system and the firmware for a field programmable gate array. In addition, we have developed dedicated software for slow control, data acquisition and online monitoring. The readout system has been tested in the laboratory and in particle beams and we present results which proof the functioning of the system, even though it is still in a prototype state.The Scalable Readout System (SRS) developed by the RD51 collaboration is a versatile and multi-purpose approach, which is used with different front-end chips to transfer data from detectors to computers. Targeting mainly micro-pattern gaseous detectors, the system is also applicable for silicon strip or pad detectors. The most frequently used front-end chip today is the APV25, originally developed for the CMS pixel detector. In the scope of the ATLAS New Small Wheel upgrade, a new front-end chip, the VMM, is developed, which has significantly improved specifications compared to the APV25
Demonstration of Gd-GEM detector design for neutron macromolecular crystallography applications
No full textThe European Spallation Source (ESS) in Lund, Sweden will become the world's
most powerful thermal neutron source. The Macromolecular Diffractometer (NMX)
at the ESS requires three 51.2 x 51.2~cm detectors with reasonable
detection efficiency, sub-mm spatial resolution, a narrow point spread function
(PSF) and good time resolution. This work presents measurements with the
improved version of the NMX detector prototype consisting of a Triple-GEM
detector with natural Gd converter and a low material budget readout. The
detector was successfully tested at the neutron reactor of the Budapest Neutron
Centre (BNC) and at the D16 instrument at the Institut Laue-Langevin (ILL) in
Grenoble. The measurements with Cadmium and Gadolinium masks in Budapest
demonstrate that the point spread function of the detector lacks long tails
that could impede the measurement of diffraction spot intensities. On the D16
instrument at ILL, diffraction spots from Triose phosphate isomerase w/
2-phosphoglycolate (PGA) inhibitor were measured both in the D16 Helium-3
detector and the Gd-GEM. The comparison between the two detectors show a
similar point spread function in both detectors, and the expected efficiency
ratio compared to the Helium-3 detector. Both measurements together thus give
good indications that the Gd-GEM detector fits the requirements for the NMX
instrument at ESS
Rate-capability of the VMM3a front-end in the RD51 Scalable Readout System
No full textThe VMM3a is an Application Specific Integrated Circuit (ASIC), specifically developed for the readout of gaseous detectors. Originally developed within the ATLAS New Small Wheel (NSW) upgrade, it has been successfully integrated into the Scalable Readout System (SRS) of the RD51 collaboration. This allows, to use the VMM3a also in small laboratory set-ups and mid-scale experiments, which make use of Micro-Pattern Gaseous Detectors (MPGDs). As part of the integration of the VMM3a into the SRS, the readout and data transfer scheme was optimised to reach a high rate-capability of the entire readout system and profit from the VMM3a’s high single-channel rate-capability of 3.6Mhits/s. The optimisation focused mainly on the handling of the data output stream of the VMM3a, but also on the development of a trigger-logic between the front-end cards and the DAQ computer. In this article, two firmware implementations of the non-ATLAS continuous readout mode are presented, as well as the implementation of the trigger-logic. Afterwards, a short overview on X-ray imaging results is presented, to illustrate the high rate-capability from an application point-of-view.The VMM3a is an Application Specific Integrated Circuit (ASIC), specifically developed for the readout of gaseous detectors. Originally developed within the ATLAS New Small Wheel (NSW) upgrade, it has been successfully integrated into the Scalable Readout System (SRS) of the RD51 collaboration. This allows, to use the VMM3a also in small laboratory set-ups and mid-scale experiments, which make use of Micro-Pattern Gaseous Detectors (MPGDs). As part of the integration of the VMM3a into the SRS, the readout and data transfer scheme was optimised to reach a high rate-capability of the entire readout system and profit from the VMM3a's high single-channel rate-capability of 3.6 Mhits/s. The optimisation focused mainly on the handling of the data output stream of the VMM3a, but also on the development of a trigger-logic between the front-end cards and the DAQ computer. In this article, two firmware implementations of the non-ATLAS continuous readout mode are presented, as well as the implementation of the trigger-logic. Afterwards, a short overview on X-ray imaging results is presented, to illustrate the high rate-capability rom an application point-of-view
Precise timing with the PICOSEC-Micromegas detector
No full textThis work presents the concept of the PICOSEC-Micromegas detector to achieve a time resolution below 30 ps. PICOSEC consists of a two-stage Micromegas detector coupled to a Cherenkov radiator and equipped with a photocathode. The results from single-channel prototypes as well as the understanding of the detector in terms of detailed simulations and preliminary results from a multichannel prototype are presented
Nanodiamond photocathodes for MPGD-based single photon detectors at future EIC
No full textWe are developing gaseous photon detectors for Cherenkov imaging applications in the experiments at the future Electron Ion Collider. CsI, converting photons in the far ultraviolet range, is, so far, the only photoconverter compatible with the operation of gaseous detectors. It is very delicate to handle due to its hygroscopic nature: the absorbed water vapour decomposes the CsI molecule. In addition, its quantum efficiency degrades under ion bombardment. These are the key reasons to quest for novel, less delicate materials for photocathodes adequate for gaseous photon detectors. Layers of hydrogenated nanodiamond particles have recently been proposed as an alternative material and have shown promising characteristics. The performance of nanodiamond photocathodes coupled to thick GEM-based detectors is the objects of our ongoing R&D. The first phase of these studies includes the characterization of thick GEM coated with nanodiamond layers and the robustness of its photoconverting properties with respect to the bombardment by ions from the multiplication process in the gaseous detector. The approach is described in detail as well as all the results obtained so far within these exploratory studies
Clean Biofuel Production and Phytoremediation Solutions from Contaminated Lands Worldwide
No full textThe overall objective of the H2020 Phy2Climate project is to build the bridge between the phytoremediation of contaminated sites with the production of clean drop-in biofuels. As the project aims for the production of high-quality drop-in biofuels like marine fuels (ISO 8217), gasoline (EN 228) and diesel (EN 590), a biorefinery concept is employed with the thermo-catalytic process (TCR®) at its centre. The produced biofuels will present no Land Use Change risks, thus, the phytoremediation will decontaminate lands from a vast variety of pollutants and make the restored lands available for agriculture, while improving the overall sustainability, legal framework, and economics of the process. In this way, Phy2Climate aims at significantly contributing to the Mission Innovation Challenge for sustainable biofuel production and to almost all UN Sustainable Development Goals, as well as to the EU Biodiversity Strategy for 2030, that is part of the European Green Deal, and to the new EU Soil Strategy for 2030 adopted in 2021. On the one hand, it is unquestionable that there is a growing demand for land, which increases tensions among the different groups of users. Land is a finite resource, and the main competitors are Feed, Food & Fuel. From the available worldwide arable land, about 71% is dedicated to animal feed, about 18% to food and only about 4% to biofuels (another 7% is for material use of crops). The multiple uttered food vs fuel debate is, actually, a food vs feed debate. However, the increasing demand for biofuels and biobased products also contributes to this tension, but in a much smaller dimension. The increasing land demand for energy crops leads to direct and indirect Land Use Change (iLUC), causing deforestation, soil erosion, loss of biodiversity and vital water resources. On the other hand, there is a significant area of land which is contaminated and, therefore, unusable for any purpose. Even worse, the investigation, registration as “contaminated site”, as well as the remediation and management of such areas are very cost-intensive, adding even more fuel to the fire.Phy2Climate project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement N° 101006912
The planispherical chamber: A parallax-free gaseous X-ray detector for imaging applications
No full textCrystallography or X-ray fluorescence experiments which require good signal to noise ratios and high position resolution can take advantage of the outstanding signal amplification capabilities of MicroPattern Gaseous Detectors (MPGDs) such as Gaseous Electron Multipliers (GEMs) coupled with the position resolution achieved by optical readout realized with CCD or CMOS cameras. Increasing the detection probability of incident radiation with thicker drift volumes in these detectors leads to a spatial resolution-limiting parallax error when employing parallel electric field lines in the drift region
Quantum Systems for Enhanced High Energy Particle Physics Detectors
No full textDevelopments in quantum technologies in the last decades have led to a wide range of applications, but have also resulted in numerous novel approaches to explore the low energy particle physics parameter space. The potential for applications of quantum technologies to high energy particle physics endeavors has however not yet been investigated to the same extent. In this paper, we propose a number of areas where specific approaches built on quantum systems such as low-dimensional systems (quantum dots, 2D atomic layers) or manipulations of ensembles of quantum systems (single atom or polyatomic systems in detectors or on detector surfaces) might lead to improved high energy particle physics detectors, specifically in the areas of calorimetry, tracking or timing
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