Accelerator Waste: A New Challenge for Radioanalytics

2007 ◽  
Author(s):  
Dorothea Schumann ◽  
Michael Wohlmuther ◽  
Jo¨rg Neuhausen
Keyword(s):  
Chemical Separation ◽  
Proton Accelerator ◽  
Accelerator Facility ◽  
Beam Dump ◽  
New Radio ◽  
Urgent Task ◽  
Theoretical Predictions ◽  
Paul Scherrer

The Paul Scherrer Institute (PSI) at Villigen (Switzerland) operates the most powerful accelerator facility in Europe. Due to the increasing quantities of accelerator waste with almost unknown radionuclide inventory, the development of new radio-analytical methods is an urgent task. Besides the characterization by γ-measurements and dose rate determinations, also the investigation of long-lived radionuclides, being probably essential for a final disposal, is required from Swiss authorities. Chemical separation is necessary for the determination of the majority of these isotopes. As a representive example for such studies, the analytics of a beam dump assembly is introduced. Samples were taken from the target E beam dump station from the 590 MeV proton accelerator facility. The content of several radionuclides with half-lives between 2 and 107 years was determined by γ-spectrometry and, after chemical separation, by Liquid Scintillation Counting (LSC) as well as Accelerator Mass Spectrometry (AMS). The results are compared with theoretical predictions. Long-term object of these studies is the elaboration of nuclide vectors, which allow the estimation of nuclide inventories by simple calculations.

scholarly journals The Meson Production Targets in the high energy beamline of HIPA at PSI

2021 ◽  
Author(s):  
Daniela Kiselev ◽  
Pierre-André Duperrex ◽  
Sven Jollet ◽  
Stefan Joray ◽  
Daniel Laube ◽  
...  
Keyword(s):  
Meson Production ◽  
High Energy ◽  
Thick Target ◽  
Proton Accelerator ◽  
Beam Power ◽  
Graphite Target ◽  
Beam Dump ◽  
Neutron Spallation Source ◽  
Spallation Source ◽  
Paul Scherrer

Two target stations in the 590 MeV proton beamline of the High Intensity Proton Accelerator (HIPA) at the Paul Scherrer Institut (PSI) produce pions and muons for seven secondary beamlines, leading to several experimental stations. The two target stations are 18 m apart. Target M is a graphite target with an effective thickness of 5 mm, Target E is a graphite wheel with a thickness of 40 mm or 60 mm. Due to the spreading of the beam in the thick target, a high power collimator system is needed to shape the beam for further transport. The beam is then transported to either the SINQ target, a neutron spallation source, or stopped in the beam dump, where about 450 kW beam power is dissipated. Targets, collimators and beam dumps are described.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

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