In this report, the effects of adding 11B4C as interlayers into Fe/Si multilayers is studied. Fe/Si multilayers are commonly used for neutron polarization at large research facilities, and improving the polarizing properties would improve their efficiency. To study this, DC magnetron sputtering was used to make different sets of samples varying interlayer thicknesses, period thicknesses, number of periods, layer thickness ratios and also testing it with steel instead of iron in the multilayers. The samples were then studied using a series of characterization techniques to study how different growth parameters affected the sample’s properties. X-ray diffraction(XRD) and selected area electron diffraction (ED) were used for studying the crystal structure of the samples. X-ray reflectometry (XRR) was used to for fitting layer thicknesses and interface widths, and also to compare reflectivities. Elastic recoil detection analysis (ERDA) was used to study the compositions changes of the samples. Vibrating sample magnetometry (VSM) gave information about how the magnetization changed between samples. Transmission electron microscopy (TEM) visualized the structure of the samples. Finally, polarized neutron reflectometry (PNR) was done at Institute Laue Langevin (ILL), revealing the actual polarization of the samples. The results of the measurements concluded that for a sample with 40 periods, a period thickness of approximately 16 Å and a thickness ratio of around 0.5 for iron and silicon, using 1 Å thick 11B4C interlayers improved the polarization between the Bragg peaks by 60 %, and at the angle of the spin up peak by 130 %. The results also indicate improved polarization for samples with more or thicker periods. Using low carbon steel instead of iron showed poor results for thin layers, however showed promise for thicker layers due to good reflectivity results, but further testing is required.

With the construction of the European Spallation Source (ESS) steadily approaching the operational phase, an environmental monitoring program will soon be implemented with the purpose of monitoring emissions. With regard to radiation safety, it is highly important to monitor alpha emitting radionuclides in aerosol form. Thus, an experimental investigation of direct alpha spectroscopy methods was conducted in order to evaluate the current experimental setup at Medical Radiation Physics in Malmö. Direct alpha spectroscopy measurements of aerosols collected on filters collected during combustion of earth soil samples were performed. Additionally, the natural alpha background in aerosols was intended to be assessed from filter samples collected at Hyltemossa Research Station in northern Scania (Sweden). Furthermore, simulations of direct alpha spectroscopy measurements are conducted in order to anticipate a measured spectra during normal operation but also in the case of an emergency at the ESS, simulations used calculated data by the ESS together with a dispersion model in order to track emissions to ground level concentrations. Direct alpha spectroscopy for environmental samples, was able to detect the presence of 210Po with a low approximate activity level of 2.8 mBq per filter. The well-defined peaks resulted from the use of a multi stage impactor when sampling, which lead to a high surface deposition of the particles. The simulations illustrate this further by showing the effect of surface deposition and how it highly affects the quality of the attained spectrum for both the normal operation and the emergency scenario. Simulated spectrum for normal operation suggest the possible detection of 148Gd without any treatment of the filters. For the emergency scenario the activity level of 148Gd is much lower than from other radionuclides. Thus the simulated spectra instead show the possible need of chemical separation of the wanted radionuclide. / Den Europeiska spallationskällans (ESS) konstruktion fortgår precis vid utkanten av Lund och den börjar närma sig driftsfasen. I takt med det här kommer ett program för att säkerställa miljö, säkerhet och hälsa att startas, ett av målen kommer vara att övervaka utsläpp och säkerställa nivåer i förhållande till regelbestämda värden. Därav görs en experimentell undersökning av metoder för direkt alfaspektroskopi, som mål att utvärdera den nuvarande experimentuppställningen vid Medicinsk Strålningsfysik i Malmö. Mätningar av filter görs med direkt alfaspektroskopi, både filter med naturlig alfabakgrund och filter med innehåll uppsamlat under förbränningstest av jordprover. Filterinsamlingen av naturlig bakgrund görs vid Hyltemossa forskningsstation i nordöstra Skåne. Utöver den experimentella studien, simulering av förväntade spektrum vid mätning av uppsamlade filter görs, både vid normal drift för ESS och vid ett hypotetiskt olyckscenario där radioaktiva partiklar släpps ut. ESS egna beräkningar för utsläpp används som grund till de undersökta scenarierna. De resulterande mätningarna av jordprover gav goda resultat som styrker användandet av direkt alfaspektroskopi vid identifiering av miljöprover, närvaro av 210Po identifieras och uppskattas med beräkning till en låg aktivitetsnivå på 2.8 mBq per uppmätt filter. Grunden till den väldefinierade energitoppen för 210Po antas komma ifrån användandet av en kaskadimpaktor, vilket resulterade i en hög ytdeposition av partiklar vid insamling. Resulterande spektrum från simuleringarna för både normal operation och hypotetiskt olycksscenario fortsätter att illustrera den enormt positiva effekten av ytdeposition vid insamling. Slutsatsen från det simulerade spektrumet vid normal drift av ESS är att 148Gd kommer vara möjligt att upptäcka med den använda metoden för direkt alfaspektroskopi. För det simulerade olycksscenariot vid ESS är andelen utsläppt 148Gd i förhållande till andra radionuklider mycket lägre, vilket leder till en låg signal i spektrumet. Slutsatsen är därav att kemisk separation antagligen kommer behövas för att mäta nivåerna av 148Gd.

<p dir="ltr">Modern machine learning research has recently made impressive progress across various research disciplines, such as computer vision, natural language processing, also in scientific fields including materials and molecule discovery, chip, and circuit design. In photonics/optics area, conventional methods in designing and optimiza- tion typically demand substantial time and extensive computing resources, where machine learning approaches hold the potential to significantly elevate and expe- dite these processes. On the other hand, machine learning algorithms can benefit from optical/photonics based neuromorphic computing systems due to their unique strengths in power consumption and parallelization. This talk will focus on imple- menting machine learning algorithms to optimize the optical/ photonics device (ML for photonics) as well as building optical based computing system for ML applica- tions (photonics for ML): First, I will discuss my work using probabilistic generative model (CVAE) for designing nanopatterned photonics power splitter with arbitrage splitting ratio. The model is incorporated with adversarial censoring and active learn- ing to increase the quality of generated devices. Next, I will report a physics-guided and physics-explainable recurrent neural network for time dynamics discovery in op- tical resonances, which can precisely forecast the time-domain response of resonance features with a very short portion of the initial input. The model is trained in a two-step multi-fidelity framework for high-accuracy forecast. In the end, I will present our progress in developing free space reconfigurable optical computing sys- tems for scientific computing, which is an optical based general matrix multiplication (GEMM) hardware accelerator by engineering a spatially reconfigurable array made from chalcogenide phase change materials. A device-system co-design methodology was implemented for GEMM system optimization. The device has been demonstrated over a various of ML applications.</p>

The High Luminosity upgrade of the Large Hadron Collider (HL-LHC), necessitates that the ATLAS experiment replace their current Inner Detector (ID) system. The new Inner Tracker (ITk) will be an all silicon detector, utilising both pixel and strip sensors, with the aim of performing as well, or better than the current system - but in a much more challenging environment. The ITk Strip detector will consist of 17888 modules, ∼ 700 of which will be produced in the Scandinavian ITk Cluster - a collaboration of Copenhagen, Lund, Oslo and Uppsala university and our industrial partner NOTE. This work encompasses the journey from individual components through industrial scale module assembly and on to performance evaluation studies at the DESY II testbeam facility. Optimisation studies were performed of the correlated multi-variable calibration necessary for a glue robot to precisely and reliably dispense the two component epoxy used in the bonding of front-end electronics to the silicon sensor. Procedures and tools were developed for integrating this process into an industrial workflow, and to account for future fundamental changes, such as a switch in the epoxy utilised. To demonstrate sufficient tracking performance of ITk strip modules, even at end-of-life, testbeam campaigns of pre-irradiated modules are conducted. These campaign serve as vi-tal feasibility studies for the ITk as a whole. Reconstruction of end-cap type modules have been historically tricky, due to their complex geometry. This work presents the full integration of semi-automated end-cap type module reconstruction in the Corryvreckan testbeam analysis framework. This represent a major improvement in turnover time from raw data to final result, making the previously impossible concept of live reconstruction during testbeam campaigns within reach.

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Accelerator Mass Spectrometry (AMS) studies of rare isotopes with abundant isobars that form negative ions often require the use of large accelerators to achieve high sensitivity measurements. The Isobar Separator for Anions (ISA) is a radiofrequency quadrupole (RFQ) reaction cell system that provides selective isobar suppression for many of these isotopes in the low energy system, prior to injection into an accelerator. The ISA can then facilitate the measurement of these ions using smaller accelerators. A commercial version from Isobarex Corp. was installed in a separate low energy injection line of the 3 MV accelerator system at the A. E. Lalonde AMS Laboratory in the University of Ottawa and was tested using the measurement of 36Cl, suppressing its stable isobar 36S. The ISA includes a DC deceleration region, a combined cooling and reaction cell, and a DC acceleration region. The deceleration region reduces the beam energy from the ion source (20-35 keV) to a level that chemical reactions can occur, scattering is minimized, and that the reaction cell can accept and contain. RFQ segments along the length of the cell create a potential well, which limits the divergence of the traversing ions. DC offset voltages on these RFQ segments maintain a controlled ion velocity through the cell. Helium was used as a cooling gas to further decelerate the ions, facilitating charge exchange between 36S and a reaction gas. Helium provided the highest transmission of 30-80% for chlorine anions. The reaction gas NO2 was chosen to preferentially react with sulfur. Over seven orders of magnitude reduction of sulfur to chlorine was observed. After exiting the cell, the beam is reaccelerated prior to injection into the tandem accelerator for AMS analysis. Using 36Cl reference materials, it was determined that linear transmission results could be obtained for a 36Cl/Cl ratio ranging from 10−11 to 10−15. The measurements were stable over more than 24 hours of continuous measurement. A blank level on the order of 10−15 was observed. The ISA was used to measure unknown 36Cl /Cl ratio groundwater samples and the results are compared to external AMS measurements.

Startups need various resources to survive and scale, while large corporations have vast resources but search for innovations and take startups as a valuable source (Wymer and Regan, 2005). Corporate accelerators are an emerging trendy phenomenon that large organizations are adopting to collaborate with startups. Corporate accelerators take startups either from a specific industry or from all industries (Cohen and Hochberg, 2014), and achieve economic benefit either by financial returns or innovation integration (Deloitte, 2019). The types of partnerships between startups and large corporations can be classified into exploitation, exploration, or the hybrid. The exploitative partnership focus on utilizing existing capabilities from both parties, the explorative partnership aims at building new competitive advantages for involved companies, and the hybrid focus on both sides (Koza and Lewin, 2000). Therefore, the purpose of this study is to explore strategies for startups to select suitable corporate accelerators and partner with large organizations. This research used the explorative method and gathered knowledge from the literature review on startups, strategic partnership and corporate accelerator and thoughts from startups via semistructured qualitative interviews. The author compared the startups’ experience and outcome in different corporate accelerators. The findings show that early-stage startups need a framework to guide their process in building partnerships with large corporations. Also, corporate accelerators were found to be a good tool that brings startups with network, corporate resources, and future customers. Moreover, the key success factors in startup-corporation partnerships are trust, clear objectives, and partner compatibility. A partnership framework was developed to facilitate startups to build partnerships with large corporations through corporate accelerators. / Startups behöver olika resurser för att överleva och växa, medan stora företag har stora resurser men söker efter innovationer och ser startups som en värdefull källa (Wymer och Regan, 2005). Företagsacceleratorer är ett trendigt fenomen som stora organisationer använder för att samarbeta med startups. Företagens acceleratorer tar startups antingen från en specifik bransch eller från alla branscher (Cohen och Hochberg, 2014) och uppnår ekonomisk fördel antingen genom finansiell avkastning eller innovationsintegration (Deloitte, 2019). De typer av partnerskap mellan nystartade företag och stora företag kan klassificeras i exploatering, utforskning eller en hybrid. Det exploaterande partnerskapet fokuserar på att utnyttja befintliga kapaciteter från båda parter, det efterforskande partnerskapet syfte är att bygga nya konkurrensfördelar för involverade företag och hybridens fokus ligger på båda sidorna (Koza och Lewin, 2000). Därför är syftet med denna studie att utforska strategier för nystartade företag för att välja lämpliga företagsacceleratorer och samarbeta med stora organisationer. Utforskande metoden och samlade in kunskap från litteraturöversikt om startups, strategiska partnerskap och företagens acceleratorer och tankar från startups via semistrukturerade kvalitativa intervjuer. Författaren jämförde startups upplevelser och resultat i olika företagsacceleratorer. Resultaten visar att startups i tidigt skede behöver ett ramverk för att styra deras process för att skapa samarbeten med stora företag. Även företagens acceleratorer visade sig vara ett bra verktyg som ger startups nätverk, företagsresurser och framtida kunder. Vidare så är de viktigaste framgångsfaktorerna i partnerskap mellan startups förtroende, tydliga mål och parternas kompatibilitet. Ett ramverk för partnerskap utvecklades för att underlätta för startups att skapa samarbeten med stora företag genom företagsacceleratorer.

The corporate accelerator Ericsson ONE, at the multinational networking and telecommunications company Ericsson headquartered in Sweden, is subject to this master thesis research. Within the organization, there was a need for a new business performance measurement system for indicating the performance and success of Ericsson ONE. The objective of this research was to find suitable frameworks and methods that can be applied when developing a customized business performance measurement system for a corporate accelerator. The goal was then to identify relevant measurements and Key Performance Indicators for Ericsson ONE to use and to visualize that data to communicate it to the users. This has been a qualitative study with ten conducted semi-structured, in-depth interviews with representatives from different departments at Ericsson ONE. Additionally, interviews were also made with representatives from an external accelerator program. The study has been following a three-step method for assessing and developing a business performance measurement system in a structured way. It resulted in a mockup of a dashboard where data for the new business performance measurements both can be collected and visualized. To ensure all important areas and perspectives of the organization are covered, the strategy performance management tool Balanced Scorecard was applied. / Företagsacceleratorn Ericsson ONE i det multinationella nätverks- och telekommunikationsföretaget Ericsson med huvudkontor i Sverige är uppdragsgivaren för detta examensarbete. Inom organisationen fanns ett behov av ett mätsystem för att indikera hur Ericsson ONE utvecklas och för att se vilken framgång som sker. Syftet med denna uppsats var att hitta lämpliga ramar och metoder för att utveckla ett anpassat mätsystem till en företagsaccelerator. Målet var att för Ericsson ONE identifiera relevant mätbar data utifrån lämpliga ramverk samt att visualisera och kommunicera denna data för användarna. Denna kvalitativa studie har genomförts genom att representanter från olika delar av Ericsson ONE har intervjuats på ett semistrukturerat sätt. Även representanter från ytterligare ett acceleratorprogram har inkluderats. Projektet har följt en trestegsmetod för att utvärdera och utveckla ett mätsystem på ett strukturerat sätt. Detta resulterade i att en mockup för en dashboard har utvecklats där data och mätindikatorerna kan samlas ihop och visualiseras. För att säkerställa att alla viktiga områden och perspektiv i organisationen täcks, användes strategihanteringsverktyget Balanced Scorecard.

<p> The simulation of soft tissue deformations has many practical uses in the medical field such as diagnosing medical conditions, training medical professionals and surgical planning. While there are many good computational models that are used in these simulations, carrying out the simulations is time consuming especially for large systems. This is because most simulators are based on software, which are run on general-purpose computers (GPC) that are not optimized to carry out the operations needed for simulation. In order to improve the performance of these simulators, field-programmable-gate-arrays (FPGA) based accelerators for carrying out Matrix-by-Vector multiplications (MVM) have been implemented by Ramachandran in 1998 and Zhuo et. al. in 2005. Zhuo et. al. also looked at the best ways to store a matrix in memory, and how this is affected by certain properties of the matrix.</p> <p> A better approach is to implement an accelerator for carrying out all operations required for simulation on hardware. In this study we propose a hardware accelerator for simulating soft-tissue deformation using finite-difference approximation of elastodynamics equations based on conjugate-gradient inversion of sparse matrices. We designed and implemented the accelerator, which is optimized for use with sparse matrices, on FPGA. We also conducted performance and resource requirements analysis for the accelerator. Our results show this approach is capable of achieving sufficiently high computational rate for carrying out real-time simulation; even with large grids or meshes. Finally, we developed computational models for carrying out real-time simulation of tissue deformation.</p> / Thesis / Master of Applied Science (MASc)