Search results for "beam [muon]"
showing 10 items of 30 documents
Charge breeding at GANIL: Improvements, results, and comparison with the other facilities
2019
International audience; The 1+/n+ method, based on an ECRIS charge breeder (CB) originally developed at the LPSC laboratory, is now implemented at GANIL for the production of Radioactive Ion Beams (RIBs). Prior to its installation in the middle of the low energy beam line of the SPIRAL1 facility, the 1+/n+ system CB has been modified based on the experiments performed on the CARIBU Facility at Argone National Laboratory. Later, it has been tested at the 1+/n+ LPSC test bench to validate its operation performances. Charge breeding efficiencies as well as charge breeding times have been measured for noble gases and alkali elements. The commissioning phase started at GANIL in the second half-y…
Practical Calculation Models for Column Footing and Comparison with Experimental Data
2017
In this paper, a simplified calculation model for the prediction of the load-carrying capacity of an RC column footing with a square cross section is presented. A detailed background of available experimental data and existing models for the prediction of the load-carrying capacity of slender and deep footings is presented. Cases of flexural failure and punching shear failures for slender footing and concrete strut crushing and tie yielding in deep members are analyzed. The aim of the paper is to propose a simple design formula for slender and deep footing verified by available experimental data and in agreement with other existing expressions. Expressions of the maximum mechanical ratio of…
Skull Bone Defects Reconstruction with Custom-Made Titanium Graft shaped with Electron Beam Melting Technology: Preliminary Experience in a Series of…
2017
Background: Cranioplasty represents a challenge in neurosurgery. Its goal is not only plastic reconstruction of the skull but also to restore and preserve cranial function, to improve cerebral hemodynamics, and to provide mechanical protection of the neural structures. The ideal material for the reconstructive procedures and the surgical timing are still controversial. Many alloplastic materials are available for performing cranioplasty and among these, titanium still represents a widely proven and accepted choice. Methods: The aim of our study was to present our preliminary experience with a “custom-made” cranioplasty, using electron beam melting (EBM) technology, in a series of ten patien…
Efficient transfer of positrons from a buffer-gas-cooled accumulator into an orthogonally oriented superconducting solenoid for antihydrogen studies
2012
Positrons accumulated in a room-temperature buffer-gas-cooled positron accumulator are efficiently transferred into a superconducting solenoid which houses the ATRAP cryogenic Penning trap used in antihydrogen research. The positrons are guided along a 9 m long magnetic guide that connects the central field lines of the 0.15 T field in the positron accumulator to the central magnetic field lines of the superconducting solenoid. Seventy independently controllable electromagnets are required to overcome the fringing field of the large-bore superconducting solenoid. The guide includes both a 15° upward bend and a 105° downward bend to account for the orthogonal orientation of the positron accu…
Thin Film Characterisation Using MeV Ion Beams
2009
This chapter focuses on the characterisation of very thin films having thicknesses from a few nanometres to tens of nanometres. The driving force for the ion beam analysis community has mostly been the rapid development of microelectronics — all the elements in new thin SiO2 replacing dielectrics, diffusion barriers, and silicide contacts need to be analysed with a depth resolution even better than a nanometre. This together with new film deposition techniques like atomic layer deposition (ALD) [1] have given a push to the ion beam analysis community to develop new and better techniques using energetic (>0.5 MeV) ion beams.
Stress gradient versus strain gradient constitutive models within elasticity
2014
Abstract A stress gradient elasticity theory is developed which is based on the Eringen method to address nonlocal elasticity by means of differential equations. By suitable thermodynamics arguments (involving the free enthalpy instead of the free internal energy), the restrictions on the related constitutive equations are determined, which include the well-known Eringen stress gradient constitutive equations, as well as the associated (so far uncertain) boundary conditions. The proposed theory exhibits complementary characters with respect to the analogous strain gradient elasticity theory. The associated boundary-value problem is shown to admit a unique solution characterized by a Helling…
Simplified model for compressive response of RC column footing with square cross-section
2017
Abstract In this paper, a simplified calculus model for the prediction of the compressive response of RC column footing with a square cross-section is presented. As it is well-known RC concrete footing are designed adopting uniform contact pressures on the substrate and assuming a strut and tie model in deep members and a cantilever beam or slab model in flexible members. Deep and flexible members are distinguished in literature only based on the tangent of the angle expressed as the ratio between the depth and the shear span of the footing. In this paper, several subgrade contact pressures distribution for column footings (rigid or soft soils) were considered in developing a mechanical mod…
First Characterization of Novel Silicon Carbide Detectors with Ultra-High Dose Rate Electron Beams for FLASH Radiotherapy
2023
Ultra-high dose rate (UHDR) beams for FLASH radiotherapy present significant dosimetric challenges. Although novel approaches for decreasing or correcting ion recombination in ionization chambers are being proposed, applicability of ionimetric dosimetry to UHDR beams is still under investigation. Solid-state sensors have been recently investigated as a valuable alternative for real-time measurements, especially for relative dosimetry and beam monitoring. Among them, Silicon Carbide (SiC) represents a very promising candidate, compromising between the maturity of Silicon and the robustness of diamond. Its features allow for large area sensors and high electric fields, required to avoid ion r…
Nanomanufacturing/Nanotechnology
2008
This chapter provides comprehensive knowledge regarding the fabrication of nanoproducts and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques, such as nanomachining (ultra-precision) and new trends in improving nanoprocesses taking into account AFM, laser beam machining, electron beam machining processes are overviewed. The background of nanomachining processes, including typical machining operations such as turning, milling and grinding and different construction materials (metallic and nonmetallic), is outlined. The physical mechanisms responsible for the transition from brittle to ductile regime machining are explained. Mo…
Nanosecond laser surface modification of AISI 304L stainless steel: Influence the beam overlap on pitting corrosion resistance
2014
Abstract Surface modifications of AISI 304L stainless steel by laser surface melting (LSM) were investigated using a nanosecond pulsed laser-fibre doped by ytterbium at different overlaps. The objective was to study the change in the corrosion properties induced by the treatment of the outer-surface of the stainless steel without modification of the bulk material. Different analytical techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and glow discharge optical emission spectrometry (GDOES) were used to characterize the laser-melted surface. The corrosion resistance was evaluated in a chloride solution at room temperature by electrochemical tests. The results sh…