Deployment of the RASP System for Cutting a Contaminated Power Reactor Turbine Shaft

2003 ◽  
Author(s):  
M. J. Sanders ◽  
H. Jeanes ◽  
S. Fray ◽  
H.-U. Arnold
Keyword(s):  
New Technology ◽  
Cutting Temperature ◽  
Development Program ◽  
High Energy ◽  
Low Energy ◽  
High Dose ◽  
Metal Artefacts ◽  
Turbine Shaft ◽  
Set Up

A need was identified for the in-situ size reduction of large components such as glove boxes, tanks and other components. A development programme resulted in a new cutting method that could be remotely deployed for the in-situ segmentation of large components of this type. RWE NUKEM has selected RASP as acronym for this technology Remotely-Operated Advanced Segmentation Process or RASP. A review of the standard manual cutting methods highlighted a number of significant shortcomings including operative safety; high energy cutting tools generating high temperatures; spread of contamination over wide areas; risk from sharp edges and operative fatigue. The development of new technology was therefore focused on improving safety for operatives and developing an inherently safe and flexible technology, which can be used for in-situ segmentation of any large components of various sizes and configurations. Important criteria included: minimal space requirements; fast set up times for use in confined spaces or high dose areas; the ability to cut in any direction; the ability to cut virtually any material and geometry; the minimization of secondary waste and low cutting temperature so flammable materials can be cut. It was concluded that a dry low energy mechanical cutting principle, which did not require cooling, would meet these criteria. The development program produced a low energy tool that uses the principles of a reciprocating saw together with a novel operating system that applies the principles of fuzzy logic. RASP technology can be used for virtually any cutting task and is among the safest and most versatile segmentation technologies for the in-situ processing of nuclear components. After completing a test programme in which a number of metal artefacts were segmented, RASP was been set up to cut a redundant SGHWR turbine shaft into pieces to facilitate packaging. The complete turbine assembly is a large heavy item with a steel shaft of 430mm diameter. The modular RASP framework was set up to enclose the unit and the system put to work and a hoist was set up to support the cut portion of the shaft on completion of the cut. The work was completed safely and without incident.

scholarly journals The High Energy Materials Science Beamline (HEMS) at PETRA III

2013 ◽  
Vol 772 ◽  
pp. 57-61 ◽  
Author(s):  
Norbert Schell ◽  
Andrew King ◽  
Felix Beckmann ◽  
Torben Fischer ◽  
Martin Müller ◽  
...  
Keyword(s):  
Smart Materials ◽  
Materials Science ◽  
High Energy ◽  
Test Facility ◽  
Polycrystalline Materials ◽  
Energy Materials ◽  
Friction Stir ◽  
Materials Research ◽  
Set Up

The HEMS beamline at PETRA III has a main energy of 120 keV, is tunable in the range 30-200 keV, and optimized for sub-micrometer focusing with Compound Refractive Lenses. Design, construction, and main funding was the responsibility of the Helmholtz-Zentrum Geesthacht, HZG. Approximately 70 % of the beamtime is dedicated to Materials Research, the rest reserved for “general physics” experiments covered by DESY, Hamburg. The beamline P07 in sector 5 consists of an undulator source optimized for high energies, a white beam optics hutch, an in-house test facility and three independent experimental hutches, plus additional set-up and storage space for long-term experiments. HEMS has partly been operational since summer 2010. First experiments are introduced coming from (a) fundamental research for the investigation of the relation between macroscopic and micro-structural properties of polycrystalline materials, grain-grain-interactions, recrystallisation processes, and the development of new & smart materials or processes; (b) applied research for manufacturing process optimization benefitting from the high flux in combination with ultra-fast detector systems allowing complex and highly dynamic in-situ studies of microstructural transformations, e.g. in-situ friction stir welding; (c) experiments targeting the industrial user community.

Gettering Behavior of Transition Metals in Low Energy, High Dose Ion Implanted Silicon

2012 ◽  
Vol 187 ◽  
pp. 283-286 ◽  
Author(s):  
Koichiro Saga
Keyword(s):  
Transition Metals ◽  
High Energy ◽  
Low Energy ◽  
Silicon Surfaces ◽  
High Dose ◽  
Metal Impurities ◽  
Surface Metal ◽  
Recombination Centers ◽  
Detrimental Impact ◽  
Ion Implanted

Metallic contamination on silicon surfaces has a detrimental impact on ULSI device performance and yield. Surface metal impurities degrade gate oxide integrity, while metal impurities dissolved in silicon provide recombination centers, resulting in junction leakage. Surface metal impurities penetrate silicon by the collision with dopant during ion implantation and are also diffused in silicon by subsequent annealing [. If metal impurities are present around junctions, they can cause junction leakage. In order to avoid the junction leakage, metal impurities must be away from junction. It was reported that iron can be gettered in the region of dopants implanted at high energy [. On the other hand, little work has been reported on the behavior of metal impurities in shallow junction. In this study, the gettering behavior of various transition metals in low-energy and high-dose ion-implanted silicon has been demonstrated.

scholarly journals Environmental and diagenetic controls on the morphology and calcification of the Ediacaran metazoan Cloudina

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amy Shore ◽  
Rachel Wood
Keyword(s):  
Mechanical Strength ◽  
Tube Wall ◽  
High Energy ◽  
Early Diagenesis ◽  
Low Energy ◽  
Post Mortem ◽  
Relative Thickness ◽  
Controlled Morphology ◽  
Globally Distributed

AbstractCloudina is a globally distributed Ediacaran metazoan, with a tubular, funnel-in-funnel form built of thin laminae (ca. 1–10 μm). To what degree local environmental controlled morphology, and whether early diagenesis controlled the degree of calcification of Cloudina, is debated. Here we test these hypotheses by considering assemblages from four, coeval localities from the Upper Omkyk Member, Nama Group, Namibia, from inner ramp to mid-ramp reef across the Zaris Subbasin. We show that sinuosity of the Cloudina tube is variable between sites, as is the relative thickness of the tube wall, suggesting these features were environmentally controlled. Walls are thickest in high-energy reef settings, and thinnest in the low-energy, inner ramp. While local diagenesis controls preservation, all diagenetic expressions are consistent with the presence of weakly calcified, organic-rich laminae, and lamina thicknesses are broadly constant. Finally, internal ‘cements’ within Cloudina are found in all sites, and pre-date skeletal breakage, transport, as well as syn-sedimentary botryoidal cement precipitation. Best preservation shows these to be formed by fine, pseudomorphed aragonitic acicular crystals. Sr concentrations and Mg/Ca show no statistically significant differences between internal Cloudina cements and botryoidal cements, but we infer all internal cements to have precipitated when Cloudina was still in-situ and added considerable mechanical strength, but may have formed post-mortem or in abandoned parts of the skeleton.

Si NWs Conversion to Si-SiC Core-Shell NWs by MBE

2015 ◽  
Vol 821-823 ◽  
pp. 965-969
Author(s):  
Fernando Lloret ◽  
D. Araujo ◽  
M.P. Villar ◽  
L. Liu ◽  
Konstantinos Zekentes
Keyword(s):  
Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Si Nanowires ◽  
Transmission Electron ◽  
Set Up

Si nanowires (NWs) samples have been converted to silicon carbide (SiC) NWs at different conditions of substrate temperature in an ultra-high vacuum using a molecular beam epitaxy (MBE) set-up. Auger electron spectroscopy (AES) and reflection high-energy electron diffraction (RHEED) have been in-situ carried out to control the growth process. Scanning electron microscopy (SEM) and conventional transmission electron microscopy (CTEM) have been used to characterize the resulting nanostructures. In addition, the samples have been prepared by focused ion beam (FIB) in order to have electron-transparently lamellas for TEM with the interface nanowire-substrate. SiC/Si shell/core NWs free of planar defects have been obtained for conversion tmpratures lower than 800oC.

Blunt major trauma: now two different diseases?

2020 ◽  
Vol 81 (4) ◽  
pp. 1-3
Author(s):  
Timothy Coats
Keyword(s):  
Energy Transfer ◽  
Major Trauma ◽  
Trauma System ◽  
High Energy ◽  
Low Energy ◽  
Older Person ◽  
Younger Patients ◽  
Low Energy Transfer ◽  
Set Up ◽  
The Uk

Major trauma in the UK has changed and can now be thought of as two different diseases: the traditional type of high energy transfer major trauma occurring in younger patients, and low energy transfer major trauma (usually an older person falling on one level). The current NHS trauma system is not well set up to treat low energy transfer major trauma – adapting to the changing disease is the next big challenge.

Argon Ion Bombardment During Molecular Beam Epitaxy of Ge (001)

1988 ◽  
Vol 128 ◽  
Author(s):  
Eric Chason ◽  
K. M. Horn ◽  
J. Y. Tsao ◽  
S. T. Picraux
Keyword(s):  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Ion Beam ◽  
High Energy ◽  
Low Energy ◽  
High Energy Electron ◽  
Argon Ion Bombardment ◽  
Argon Ion

ABSTRACTUsing in situ, real-time reflection high energy electron diffraction (RHEED), we have measured the evolution of Ge (001) surface morphology during simultaneous molecular beam epitaxy and Ar ion beam bombardment. Surprisingly, low-energy Ar ions during growth tend to smoothen the surface. Bombardment by the ion beam without growth roughens the surface, but the surface can be reversibly smoothened by restoring the growth beam. We have measured the effect of such “ion beam growth smoothening” above and below the critical temperature for intrinsic growth roughening. At all measured growth temperatures the surface initially smoothens, but below the critical roughening temperature the final surface morphology is rough whereas above this temperature the final morphology is smooth.

scholarly journals Intra-Cascade Surface Recombination of Point Defects During Ion Bombardment of Ge (001)

1993 ◽  
Vol 316 ◽  
Author(s):  
J. A. Floro ◽  
B. K. Kellerman ◽  
E. Chason ◽  
S. T. Picraux ◽  
D. K. Brice ◽  
...  
Keyword(s):  
Point Defects ◽  
Surface Recombination ◽  
Ion Bombardment ◽  
High Energy ◽  
Low Energy ◽  
Yield Reduction ◽  
High Energy Electron ◽  
Near Surface ◽  
Large Numbers

ABSTRACTLow energy Ar and Xe ion bombardment of Ge (001) produces large numbers of point defects on the Ge surface and in the near-surface regions. Defect concentrations on the surface are detected and quantified in real time during bombardment using in situ Reflection High Energy Electron Diffraction (RHEED). We report the energy dependence of the defect yield for 70–500 eV Ar and Xe ion bombardment, and the temperature dependence of the defect yield (defects/ion) during 200 eV ion bombardment. The defect yield drops rapidly as the substrate temperature during bombardment is varied from 175 K to 400 K. We attribute the yield reduction to surface recombination of adatoms and vacancies produced in the same collision cascade.

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