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Feasible Workspace for Robotic Fiber PlacementMoutran, Serge Riad 21 May 2002 (has links)
Online consolidation fiber placement is emerging as an automated manufacturing process for the fabrication of large composite material complex structures. While traditional composite manufacturing techniques limited the products' size, geometrical shapes and laminate patterns, robotic automation of the fiber placement process allows the manufacture of complex bodies with any desired surface pattern or towpreg's direction. Therefore, a complete understanding of the robot kinematic capabilities should be made to accurately position the structure's substrate in the workcell and to compute the feasible product dimensions and sizes.
A Matlab algorithm is developed to verify the feasibility of straight-line trajectory paths and to locate all valid towpreg segments in the workspace, with no focus on optimization. The algorithm is applied preliminary to a three-link planar arm; and a 6-dof Merlin robot is subsequently considered to verify the towpreg layouts in the three-dimensional space. The workspace is represented by the longest feasible segments and plotted on parallel two-dimensional planes. The analysis is extended to locate valid square areas with predetermined dimensions. The fabrication of isotropic circular coupons is then tested with two different compaction heads. The results allow the formulation of a geometric correlation between the end-effector dimensional measures and the orientation of the end-effector with respect to the towpreg segments. / Master of Science
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Miniaturization of Linear Ion Traps and Ion Motion Study in a Toroidal Ion Trap Mass AnalyzerLi, Ailin 01 August 2017 (has links)
I describe the miniaturization of a linear-type ion trap mass spectrometer for possible applications in portable chemical analysis, and demonstrate the advantages of using lithographically patterned electrode plates in realizing an ion trap with dimension r0 less than 1 mm. The focus of the work was to demonstrate the viability and feasibility of the patterned electrode approach to trap miniaturization, and also to discover potential obstacles to its use. Planar ceramic substrates were patterned with metal electrodes using photolithography. Plates that were originally used in a linear trap with a half-spacing (r0) of 2.19 mm were positioned much closer together such that r0 = 0.95 mm. A capacitive voltage divider provided different radiofrequency (RF) amplitudes to each electrode, and the capacitor values were adjusted to provide the correct electric field at this closer spacing. Electron ionization mass spectra of toluene and dichloromethane demonstrate instrument performance with better than unit mass resolution. Compared with the larger plate spacing, the signal intensity is reduced, corresponding to the reduced trapping capacity of the smaller device, but the mass resolution of the larger device is retained. A further miniaturized linear ion trap with a half-spacing of 362 µm was designed and tested. A series of obstacles and troubleshooting on ion source, analytical method, and electronics were present. These experiments show promise for further miniaturization using patterned ceramic plates and provide a guide for the ion trap miniaturization. The feasibility of a wire linear ion trap was also demonstrated. Unit mass resolution was obtained, indicating a promise for further optimization and miniaturization of the wire linear ion trap. In addition to the practical experiments on the miniaturized linear ion traps, I theoretically studied ion motion in the toroidal ion trap using SIMION simulations, which show classical chaotic behavior of single ions. The chaotic motion is a result of the non-linear components of the electric fields as established by the trap electrodes, and not by Coulombic interaction from other ions. The chaotic behavior was observed specifically in the ejection direction of ions located in non-linear resonance bands within and adjacent to the region of stable trapping. The non-linear bands crossing through the stability regions correspond to hexapole resonance conditions, while the chaotic ejection observed immediately adjacent to the stable trapping region corresponds to a "fuzzy" ejection boundary. Fractal-like patterns were obtained in a series of zoomed-in regions of the stability diagram.
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Ontology Driven Development For Hla FederatesKoksal Algin, Ceren Fatma 01 June 2010 (has links) (PDF)
This thesis puts forth a process for ontology driven distributed simulation through a case
study. Ontology is regarded as a domain model, including objects, attributes, methods and
object relations. The case study involves trajectory simulation. A trajectory simulation is a
piece of software that calculates the flight path and other parameters of a munition, such as
its orientation and angular rates, from launch to impact. Formal specification of trajectory
simulation domain is available as a domain model in the form of an ontology, called
Trajectory Simulation ONTology (TSONT). Ontology driven federation development
process proposed in this thesis is executed in three steps. The first step is to analyze the
TSONT and to create instances of individuals guided by the requirements of the targeted
simulation application, called Puma Trajectory Simulation. Puma is the simulation of a
ficticious air-to-ground guided bomb. The second step is to create the High Level
Architecture(HLA) Federation Object Model (FOM) using Puma Simulation individuals.
FOM will include the required object and interaction definitions to enable information
exchange among federation members, including the Puma federate and the Exercise
Manager federate. Transformation from the ontology to FOM is realized in two ways:
manually, and by using a tool called OWL2OMT. The third step is to implement the
Trajectory Simulation federation based on the constructed FOM. Thus, the applicability of
developing HLA federates and the federation under the guidance of ontology is
demonstrated.
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Ontology Based Reuse Infrastructure For Trajectory SimulationDurak, Umut 01 July 2007 (has links) (PDF)
In this research, we developed an ontology based reuse infrastructure for trajectory simulation and investigated the use of ontologies and domain engineering practices to develop a formalized methodology to make use of the experience and knowledge leveraged from the past trajectory simulation projects. Trajectory simulation in this context is a computational tool to calculate the flight path and other parameters of munition such as its orientation or angular rates during its operation
In this thesis, engineering knowledge to simulate the trajectory of a munition is captured in an ontology called Trajectory Simulation ONTology (TSONT). Concepts of trajectory simulation and the relation among these concepts are captured by using Web Ontology Language and presented as a domain model that is available for reuse.
Using the formalized domain knowledge, reuse infrastructure specifications are constructed to enable the reuse of software artifacts for two main programming paradigms, which are object oriented programming and function oriented programming. UML and application frameworks are used when constructing for object oriented paradigm. And data flow diagrams are used to formalize the design of the function oriented simulations to compute the trajectory of munition. Object oriented and function oriented platform independent designs are constructed to specify the infrastructure using the knowledge captured in TSONT and made available for reuse. With constructing two different designs for two different paradigms by using the same domain model, evidence of knowledge reuse were produced.
Three different case studies were carried out as infrastructure implementation. In the first case study, an object oriented application framework was developed in MATLAB for six degrees of freedom trajectory simulation using platform independent object oriented design. This framework is reused to develop two different simulations. Using the developed framework for two applications produced evidence of code reuse. In the second case, a point mass trajectory simulation framework is designed to be implemented in C# reusing the same platform independent object oriented design. This case produced the evidence of design reuse. In the last case study, a MATLAB Simulink Blockset is developed for point mass unguided trajectory simulations and two different simulations are built using the Blockset. By this case, we collected the evidence of code reuse also in function oriented paradigm.
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High performance algorithms to improve the runtime computation of spacecraft trajectoriesArora, Nitin 20 September 2013 (has links)
Challenging science requirements and complex space missions are driving the need for fast and robust space trajectory design and simulation tools. The main aim of this thesis is to develop new and improved high performance algorithms and solution techniques for commonly encountered problems in astrodynamics. Five major problems are considered and their state-of-the art algorithms are systematically improved. Theoretical and methodological improvements are combined with modern computational techniques, resulting in increased algorithm robustness and faster runtime performance. The five selected problems are 1) Multiple revolution Lambert problem, 2) High-fidelity geopotential (gravity field) computation, 3) Ephemeris computation, 4) Fast and accurate sensitivity computation, and 5) High-fidelity multiple spacecraft simulation. The work being presented enjoys applications in a variety of fields like preliminary mission design, high-fidelity trajectory simulation, orbit estimation and numerical optimization. Other fields like space and environmental science to chemical and electrical engineering also stand to benefit.
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Contrôle d'écoulements en vue d'un pilotage alternatif pour les projectiles d'artillerie / Flow control for alternative projectile steeringLibsig, Michel 14 January 2016 (has links)
Afin d'atteindre leur cible, les projectiles guidés d'artillerie nécessitent d'être dotés d'un dispositif de pilotage. Des surfaces de contrôle déployables et orientables sont donc nécessaires. Toutefois, le montage de gouvernes ajustables sur une ogive est une tâche mécaniquement ardue. En effet, lors du tir effectué par canon, l'équipement de bord subit une accélération significative, ce qui implique que des liaisons mécaniques particulièrement robustes doivent être conçues entre les ailettes et le corps. Cette technologie est bien maîtrisée lorsqu'elle est employée sur des projectiles de gros calibre, mais devient bien plus compliquée quand elle doit être adaptée pour être intégrée dans des petits ou moyens calibres. Néanmoins, dans des conditions de vol supersonique, des ondes de choc qui interagissent avec des surfaces solides sont susceptibles de considérablement modifier la distribution de pression. Ce principe a permis d'imaginer une méthode alternative de pilotage de projectiles supersoniques en exploitant des ondes de choc générées au moyen de petites perturbations créées à partir d'un micro-actionneur de forme cylindrique, aussi appelé micro-plot. Comme les forces de portance exercée sur un corps sont essentiellement dues à une pression appliquée sur de grandes surfaces, il a été choisi de se baser sur une configuration stabilisée par empennage. En vue de simplifier l'étude, le travail a été effectué sur un projectile académique de référence bien connu appelé le Basic Finner.Des expériences ont tout d'abord été effectuées dans la soufflerie supersonique de l'ISL sur une plaque plane comportant un plot et deux ailettes verticales. Ces mesures ont permis de valider la capacité de simulations numériques stationnaires RANS à prédire à la fois la distribution pariétale de la pression que génère un tel actionneur et le champ de vitesse de l'écoulement dans son voisinage. Les distributions de pression et de vitesse ont été mesurées en utilisant des méthodes optiques appelés Pressure Sensitive Paints (PSP) et Particle Image Velocimetry (PIV) afin d'être comparés avec les résultats de la CFD. Une étude paramétrique a ensuite été menée en se basant exclusivement sur ces simulations RANS. Ces calculs ont permis de déterminer l'emplacement optimal pour lequel le plot est le plus efficace sur toute l'enveloppe de vol du projectile. A partir de cette position optimale, deux configurations spécifiques ne générant aucun moment de roulis ont été étudiées numériquement et comparés en termes d'efficacité. En utilisant les coefficients aérodynamiques résultants de ce travail, des simulations de trajectoires à 6 degrés de liberté (6-DOF) ont été réalisées avec le code de BALCO (OTAN). Celles-ci ont permis de déterminer la déviation potentielle qui peut être obtenue sur une des deux configurations retenues en employant un tel micro-actionneur. Ces simulations 6-DOF ainsi que l'effet de du plot sur le projectile ont enfin été validés lors d'une campagne d'essai en vol libre qui a eu lieu sur le champ de tir de l'ISL. / In order to reach their target, guided artillery projectiles need some steering capability. Folding and adjustable control surfaces are thus necessary. However, mounting adjustable rudders on a shell is a difficult task, mechanically speaking. Indeed, during the gun launch, the onboard equipment undergoes significant acceleration so that robust mechanical joints have to be designed between the rudders and the body. This technique performs very well on large-caliber projectiles, but becomes more complicated when it has to be embedded in small- or medium-caliber ones. Nevertheless, under supersonic flight conditions, shock waves interacting with solid surfaces are likely to strongly modify the pressure distribution. This principle made it possible to imagine a way of steering small-caliber vehicles using shock waves generated by means of small disturbances created by a cylindrical-shaped micro-actuator, also called micro-pin. As lift forces exerted on a body are mainly due to the pressure applied to large surfaces, a finned configuration has been chosen. To simplify the study, the work has been conducted on the Basic Finner, a well known academic reference projectile.Experiments were first performed in the ISL supersonic wind tunnel on a flat plate on which a pin and two vertical projectile-like fins were mounted in order to validate the capability of steady RANS numerical simulations to predict both the pressure footprint of such an actuator and the flow velocity in its vicinity. Pressure and velocity distributions have been measured by using optical methods called Pressure-Sensitive Paint (PSP) and Particle Image Velocimetry (PIV) in order to be compared with the calculation results. A parametric study was then conducted with these RANS simulations so that the optimum location for which the pin is the most effective over the complete flight envelope of the projectile could be determined. Using this optimum position two specific no-roll momentum configurations were studied numerically and compared in terms of effectiveness. By using the aerodynamic coefficients resulting from this work, 6-Degree-Of-Freedom (6-DOF) trajectory simulations were performed with the NATO BALCO code on one of these configurations in order to determine the potential deviation which can be obtained with such an actuator. These 6-DOF simulations as well as the pin effect on the projectile could finally be validated during a free-flight campaign that took place at the ISL open-range testing site.
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Fuel Efficiency Analysis of Optimized Flights / Bränsleeffektiveitet analy av optimerade flygningarBettar, Michael January 2022 (has links)
The impact of air travel on the climate, along with its increasing share in CO2 emissions have raised the demand for sustainable air travel solutions. The current aircraft technologies have seen significant improvement throughout the years. Although, the rate at which new aircraft technologies are developed can not keep up with the increased demand for air travel. Hence, a different approach to reduce the aviation’s impact on climate can be achieved by optimizing the vertical flight path in order to reduce the fuel consumption, i.e. using dynamic programming. Upon departure, an optimization of the vertical flight path is initiated and an optimal flight plan is suggested to the flight crew. The fuel saving produced by the optimal flight plan is a potential saving that can only be fully achieved if the flight crew chose to fly according to the optimized flight path. However, restrictions from the Air Traffic Control, as well as the flight crew’s willingness to follow the optimized flight path can affect the achieved saving. Hence, a tool is developed in order to compute trip fuel consumption from post-flight data obtained from the Automatic Dependent Surveillance-Broadcast (ADS-B) surveillance technology. A method to identify the start and end positions of cruise segments is successfully implemented. Two methods of calculating the fuel are implemented and compared. The first method is based on simulating the actual flight, which uses the same performance model as for the simulation of the operational flight plan trip and optimized trip. The second method is based on utilizing the ADS-B data to obtain the aircraft speed which in return can be used as a parameter to obtain the fuel flow of the aircraft, hence the trip is not simulated. The results reveals that the simulation method produces flight trajectories that are comparable to the operational and optimized flight plans since they use the same model structure. However, using ADS-B data to obtain fuel consumption represents the actual flight trajectory more accurately. Furthermore, an optimization algorithm based on the onboard Flight Management Computer is implemented. According to the results, the FMC optimization offers a sufficient optimization of the cruise phase, when compared to the OFP trip, however performs worse than the dynamic programming, which provides a global optimal solution. / Flygresornas inverkan på klimatet, tillsammans med dess ökande andel av CO2-utsläppen, har ökat kraven på hållbara flygplanslösningar. Den nuvarande flygplansteknologin har genomgått betydande förbättringar genom åren. Men takten för vilken ny flygplansteknik utvecklas kan inte hålla jämna steg med den ökade efterfrågan på flygresor. Däremot kan ett annat tillvägagångssätt för att minska flygets påverkan på klimatet uppnås genom att optimera den vertikala flygvägen för att minska bränsleförbrukningen, d.v.s. med hjälp av högupplösta väderdata. Vid avgång initieras en dynamisk programmering där optimering av den vertikala flygbanan och en optimal färdplan föreslås för flygbesättningen. Bränslebesparingen som den optimala färdplanen ger är en besparingspotential som endast kan uppnås fullt ut om flygbesättningen väljer att flyga enligt den. Restriktioner från flygledningen, samt flygbesättningens vilja att följa den optimerade färdplanen kan dock påverka den uppnådda besparingen. Därav utvecklas ett verktyg för att beräkna färdens bränsleförbrukning från postflight data erhållna från Automatic Dependent Surveillance-Broadcast (ADS-B) övervakningsteknologi. En metod för att identifiera start- och slutpositionerna för kryssningssegment implementeras framgångsrikt. Två metoder för att beräkna bränslet implementeras och jämförs. Den första metoden baseras på att simulera den faktiska flygningen. Denna metod använder samma prestandamodell som för simuleringen av den operativa färdplanens resa och den optimerade resan. Den andra metoden baseras på att använda ADS-B-data för att erhålla flygplanets hastighet, som i sin tur kan användas som en parameter för att få fram flygplanets bränsleflöde vid en tidpunkt. Resultaten visar att simuleringsmetoden ger flygbanor som är rättvist jämförbara med de operativa och optimerade flygplanerna, då de använder samma modell. Men att använda ADS-B-data för att få bränsleförbrukning representerar den faktiska flygbanan mer exakt. Dessutom implementeras en optimeringsalgoritm baserad på den inbyggda Flight Management Computer. Enligt resultaten erhåller FMC-optimeringen en tillfredsställande optimering av kryssningsfasen, jämfört med OFP-resan, men presterar sämre än den dynamiska programmeringen, vilket alltid ger en global optimal lösning.
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Post-Flight Analysis of Fuel Consumption / Efter-flygningsanalys av bränsleförbrukningBettar, Michael January 2022 (has links)
The impact of air travel on the climate, along with its increasing share in CO2 emissions haveraised the demand for sustainable air travel solutions. The current aircraft technologies haveseen significant improvement throughout the years. Although, the rate at which new aircrafttechnologies are developed can not keep up with the increased demand for air travel. Hence, adifferent approach to reduce the aviation’s impact on climate can be achieved by optimizing thevertical flight path in order to reduce the fuel consumption, i.e. using dynamic programming.Upon departure, an optimization of the vertical flight path is initiated and an optimal flight planis suggested to the flight crew. The fuel saving produced by the optimal flight plan is a potential saving that can only be fullyachieved if the flight crew chose to fly according to the optimized flight path. However, restrictionsfrom the Air Traffic Control, as well as the flight crew’s willingness to follow theoptimized flight path can affect the achieved saving. Hence, a tool is developed in order tocompute trip fuel consumption from post-flight data obtained from the Automatic DependentSurveillance-Broadcast (ADS-B) surveillance technology. A method to identify the start andend positions of cruise segments is successfully implemented. Two methods of calculating thefuel are implemented and compared. The first method is based on simulating the actual flight,which uses the same performance model as for the simulation of the operational flight plantrip and optimized trip. The second method is based on utilizing the ADS-B data to obtain theaircraft speed which in return can be used as a parameter to obtain the fuel flow of the aircraft,hence the trip is not simulated. The results reveals that the simulation method produces flighttrajectories that are comparable to the operational and optimized flight plans since they use thesame model structure. However, using ADS-B data to obtain fuel consumption represents theactual flight trajectory more accurately. Furthermore, an optimization algorithm based on the on-board Flight Management Computeris implemented. According to the results, the FMC optimization offers a sufficient optimizationof the cruise phase, when compared to the OFP trip, however performs worse than the dynamicprogramming, which provides a global optimal solution / Flygresornas inverkan på klimatet, tillsammans med dess ökande andel av CO2-utsläppen, harökat kraven på hållbara flygplanslösningar. Den nuvarande flygplansteknologin har genomgåttbetydande förbättringar genom åren. Men takten för vilken ny flygplansteknik utvecklas kaninte hålla jämna steg med den ökade efterfrågan på flygresor. Däremot kan ett annat tillvägagångssättför att minska flygets påverkan på klimatet uppnås genom att optimera den vertikalaflygvägen för att minska bränsleförbrukningen, d.v.s. med hjälp av högupplösta väderdata. Vidavgång initieras en dynamisk programmering där optimering av den vertikala flygbanan och enoptimal färdplan föreslås för flygbesättningen. Bränslebesparingen som den optimala färdplanen ger är en besparingspotential som endast kanuppnås fullt ut om flygbesättningen väljer att flyga enligt den. Restriktioner från flygledningen,samt flygbesättningens vilja att följa den optimerade färdplanen kan dock påverka denuppnådda besparingen. Därav utvecklas ett verktyg för att beräkna färdens bränsleförbrukningfrån post-flight data erhållna från Automatic Dependent Surveillance-Broadcast (ADS-B) övervakningsteknologi.En metod för att identifiera start- och slutpositionerna för kryssningssegmentimplementeras framgångsrikt. Två metoder för att beräkna bränslet implementeras ochjämförs. Den första metoden baseras på att simulera den faktiska flygningen. Denna metodanvänder samma prestandamodell som för simuleringen av den operativa färdplanens resa ochden optimerade resan. Den andra metoden baseras på att använda ADS-B-data för att erhållaflygplanets hastighet, som i sin tur kan användas som en parameter för att få fram flygplanetsbränsleflöde vid en tidpunkt. Resultaten visar att simuleringsmetoden ger flygbanor somär rättvist jämförbara med de operativa och optimerade flygplanerna, då de använder sammamodell. Men att använda ADS-B-data för att få bränsleförbrukning representerar den faktiskaflygbanan mer exakt. Dessutom implementeras en optimeringsalgoritm baserad på den inbyggda Flight ManagementComputer. Enligt resultaten erhåller FMC-optimeringen en tillfredsställande optimering avkryssningsfasen, jämfört med OFP-resan, men presterar sämre än den dynamiska programmeringen,vilket alltid ger en global optimal lösning.
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A Radio Frequency Quadrupole Instrument for use with Accelerator Mass Spectrometry: Application to Low Kinetic Energy Reactive Isobar Suppression and Gas–phase Anion Reaction StudiesEliades, John Alexander 21 August 2012 (has links)
A radio frequency (rf) quadrupole instrument, currently known as an Isobar Separator for Anions (ISA), has been integrated into an Accelerator Mass Spectrometry (AMS) system to facilitate anion–gas reactions before the tandem accelerator. An AMS Cs+ sputter source provided > 15 keV ions that were decelerated in the prototype ISA to < 20 eV for reaction in a single collision cell and re-accelerated for AMS analysis. Reaction based isobar suppression capabilities were assessed for smaller AMS systems and a new technique for gas–phase reaction studies was developed.
Isobar suppression of 36S– and 12C3– for 36Cl analysis, and YF3– and ZrF3– for 90Sr analysis were studied in NO2 with deceleration to < 12 eV. Observed attenuation cross sections, σ [x 10^–15 cm^2], were σ(S– + NO2) = 6.6, σ(C3– + NO2) = 4.2, σ(YF3– + NO2) = 7.6, σ(ZrF3– + NO2) = 19. With 8 mTorr NO2, relative attenuations of S–/Cl– ~ 10^–6, C3–/Cl– ~ 10^–7, YF3–/SrF3– ~ 5 x 10^–5 and ZrF3–/SrF3– ~ 4 x 10^–6 were observed with Cl– ~ 30% and SrF3– > 90% transmission. Current isobar attenuation limits with < 1.75 MV accelerator terminal voltage and ppm impurity levels were calculated to be 36S–/Cl– ~ 4 x 10^–16, 12C3–/Cl– ~ 1.2 x 10^–16, 90YF3–/SrF3– ~ 10^–15 and 90ZrF3–/SrF3– ~ 10^–16.
Using 1.75 MV, four 36Cl reference standards in the range 4 x 10^–13 < 36Cl/Cl < 4 x 10^–11 were analyzed with 8 mTorr NO2. The measured 36Cl/Cl ratios plotted very well against the accepted values. A sample impurity content S/Cl < 6 x 10^–5 was measured and a background level of 36S–/Cl < 9 x 10^–15 was determined.
Useful currents of a wide variety of anions are produced in AMS sputter sources and molecules can be identified relatively unambiguously by stripping fragments from tandem accelerators. Reactions involving YF3–, ZrF3–, S– and SO– + NO2 in the ISA analyzed by AMS are described, and some interesting reactants are identified.
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A Radio Frequency Quadrupole Instrument for use with Accelerator Mass Spectrometry: Application to Low Kinetic Energy Reactive Isobar Suppression and Gas–phase Anion Reaction StudiesEliades, John Alexander 21 August 2012 (has links)
A radio frequency (rf) quadrupole instrument, currently known as an Isobar Separator for Anions (ISA), has been integrated into an Accelerator Mass Spectrometry (AMS) system to facilitate anion–gas reactions before the tandem accelerator. An AMS Cs+ sputter source provided > 15 keV ions that were decelerated in the prototype ISA to < 20 eV for reaction in a single collision cell and re-accelerated for AMS analysis. Reaction based isobar suppression capabilities were assessed for smaller AMS systems and a new technique for gas–phase reaction studies was developed.
Isobar suppression of 36S– and 12C3– for 36Cl analysis, and YF3– and ZrF3– for 90Sr analysis were studied in NO2 with deceleration to < 12 eV. Observed attenuation cross sections, σ [x 10^–15 cm^2], were σ(S– + NO2) = 6.6, σ(C3– + NO2) = 4.2, σ(YF3– + NO2) = 7.6, σ(ZrF3– + NO2) = 19. With 8 mTorr NO2, relative attenuations of S–/Cl– ~ 10^–6, C3–/Cl– ~ 10^–7, YF3–/SrF3– ~ 5 x 10^–5 and ZrF3–/SrF3– ~ 4 x 10^–6 were observed with Cl– ~ 30% and SrF3– > 90% transmission. Current isobar attenuation limits with < 1.75 MV accelerator terminal voltage and ppm impurity levels were calculated to be 36S–/Cl– ~ 4 x 10^–16, 12C3–/Cl– ~ 1.2 x 10^–16, 90YF3–/SrF3– ~ 10^–15 and 90ZrF3–/SrF3– ~ 10^–16.
Using 1.75 MV, four 36Cl reference standards in the range 4 x 10^–13 < 36Cl/Cl < 4 x 10^–11 were analyzed with 8 mTorr NO2. The measured 36Cl/Cl ratios plotted very well against the accepted values. A sample impurity content S/Cl < 6 x 10^–5 was measured and a background level of 36S–/Cl < 9 x 10^–15 was determined.
Useful currents of a wide variety of anions are produced in AMS sputter sources and molecules can be identified relatively unambiguously by stripping fragments from tandem accelerators. Reactions involving YF3–, ZrF3–, S– and SO– + NO2 in the ISA analyzed by AMS are described, and some interesting reactants are identified.
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