The ability for base stations to be able to beam-form their signals, directing the signal energy to specific users, is a topic of research that has been heavily studied during the last decades. The beam-forming technique aims to increase the signal-to-interference-and-noise-ratio of the user and, consequently, increase the capacity and coverage of the communication system. One such method is the Differential Beam-Forming technique, that has been developed at Ericsson Research. In this version of beam-forming, the beams can be dynamically sharpened and widened when tracking a specific terminal, to try to optimize the signal energy sent to that terminal. Beam-forming, however, makes the link-adaptation algorithm process substantially harder to perform. The reason for this is that the link-adaptation algorithm now has to take into account not only the changing radio environment, but also the changing transmit signal that is being beam-formed. Fortunately, since the beam-formed signal is known at the point of transmission, there should be a potential to utilize this knowledge to make the link-adaptation more efficient. This thesis, investigates how the link-adaptation algorithm could be changed to perform better in beam-forming setups, as well as what information from the beam-forming algorithm that could be included and utilized in the link-adaptation algorithm. This is done by designing and investigating three new link-adaptation algorithms, in the context of Differential Beam-Forming in an LTE FDD system. The algorithms that has been designed are both of a beam-forming-aware and beam-forming-unaware character, meaning if the beam-forming information is utilized within the algorithm, or not. These algorithms have been simulated for different base station antenna array-sizes. Unfortunately, due to simulator restrictions, the terminals have been simulated in a stationary environment, which has proven to be a limiting factor for the results. However, the results still show that smarter beam-forming-aware link-adaptation could possibly be used to increase the performance of the link-adaptation when using beam-forming.

In the Large Hadron Collider (LHC), particle physics events are created by colliding high energy proton beams at a number of interaction points around the ring. One of the main performance indicating parameters of the LHC is the luminosity. The luminosity is limited by, amongst other things, the strength of the beam-beam interaction. In this thesis, the effect of the beam-beam interaction on the luminosity performance of the LHC and the proposed High Luminosity Large Hadron Collider (HL-LHC) is investigated. Results from a number of dedicated, long-range beam-beam machine studies are presented and analysed. In these studies, the minimum beam-beam separation for two different beta star— optics are identified. This separation defines the minimum operational crossing angle in the LHC. The data from these studies are then compared to simulation of the dynamic aperture and the results are discussed. In addition to studies of the LHC, an analytical approach is derived in order to describe the hourglass effect, which may become a contributing factor in limiting the luminosity performance of the HL-LHC.

The design of high quality electron generators to meet specific requirements is important in the application of these devices to a variety of materials processing systems (including welding, cutting and additive manufacture), X-ray tubes for medical, scientific and industrial applications, microscopy and lithography. Designs can be analysed by field solvers, and electron trajectories plotted to provide an indication of the beam quality. Incremental improvement of designs has normally been executed by trial and error, and this can be a time consuming activity requiring expert intervention for each iteration of the design process. The unique contribution made to knowledge by this work is the application of optimisation techniques to the design of electron guns to produce beams with the required optical properties. This thesis presents a review of the design of electron guns, including a discussion of thermionic cathode material properties and their suitability for use in electron guns for processing materials, the influence of space-charge on gun design and the derivation of salient beam metrics to characterise the beam. Beam quality metrics have been developed that allow quantification of electron beam characteristics, allowing objectives to be set for the optimisation process. Additionally, a method is presented that enables real world measurements to be directly compared with modelled beams. Various optimisation methods are reviewed. A genetic algorithm was selected, which would use gun modelling and beam characterisation calculations as the objective function, as a suitable method for application to this problem. However, it was recognised that selections for the best evolutionary parameters, the population size, number of parents, the mutation rate and mutation scale, were not readily determined from published work. An investigation is presented where a range of evolutionary parameters was tested for a set of geometrical problems, which had some similarity to electron gun design but could be computed sufficiently quickly to enable an extensive survey, and the most efficient combination of parameters was identified. Detail is given of the customisation of a genetic evolutionary optimisation method for the design of electron guns. Examples are presented of electron gun design optimisation processes to meet specified beam requirements within defined geometric and electrical constraints. The results of this work show that optimum evolutionary parameter settings for the geometric problem vary with the complexity of the problem and trends have been identified. Application of these parameters to an electron gun optimisation has been successful. The derived beam parameter metrics have been applied to electron guns as an objective function. Comparisons of modelled predictions of the beam characteristics with the measured real world values have been shown to be reasonable.

Following the discovery of the Higgs-like boson at the Large Hadron Collider, there is demand for precision measurements on recent findings. The Compact Linear Collider, CLIC, is a candidate for a future linear electron-positron collider for such precision measurements. In CLIC, the beams will be brought to collisions in the multi-TeV regime through high gradient acceleration with high frequency RF power. A high intensity electron beam, the so-called drive beam, will serve as the power source for the main beam, as the drive beam is decelerated in special structures, from which power is extracted and transfered to the main beam. When the drive beam is decelerated the beam quality deteriorates and the momentum spread increases, which makes the beam transport challenging. Dedicated diagnostics to monitor the momentum profile along each bunch train and transverse profile diagnostics will be needed to guarantee the reliability of the decelerator and consequently the power source of the main beam acceleration. A test facility, CTF3, has been constructed at CERN to validate key technical aspects of the CLIC concept. The beam quality in the decelerator will be investigated in the test beam line, TBL, where several power extraction structures reduce the drive beam energy by up to 55%. At the same time, the single-bunch rms energy spread grows from the initial value of 1% to almost 6%. To monitor the parameters of such a beam is challenging but crucial for the optimization of the beamline. In this thesis we report on progress made on adapting generally used methods for beam profile measurements to the demanding conditions of a wide momentum profile. Two detector technologies are used for measuring transverse profile and momentum profile and we discuss the performance of these instruments, in the view of the large momentum spread and with the outlook towards equivalent beam profile monitors in the CLIC decelerator.

Växjö university has together with Södra developed a new green-glued laminated beam, which to be used in a building system. To make a product of the beam it is desired to also develop a building system based on the beam. An important part of such a building system is the connections. The main aim of the thesis was to design a new beam-to-beam connection in for the new green-glued laminated boards. This thesis is about to develop and test a new connection for a beam-to-beam connection in the building system. The requirements set on the connection was that it should be used in an office building with a beam length of 6 m, the connection should be fast to assemble and invisible. The report thoroughly describes the conceptual design, the development and test of the connection. Five different types of connections were designed in the conceptual design phase. One of these connections fulfilled the requirements and was taken to the development and testing phase. Three versions of the connection were tested. The report describes how the green-glued laminated beams with the connections were tested in a testing machine until the failure occurs. The developed connection could fulfil the requirements set on the connection. One version of the connection was even stronger than the green-glued laminated beams.

Transverse load distribution behavior amongst bridge girders is influenced by many parameters including girder material properties, spacing, skew, deck design, and stiffening element interactions. In order to simply and conservatively approximate the bridge superstructure load distribution between girders, the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications contain load distribution factor (LDF) equations for many common bridge types. The Texas Department of Transportation (TxDOT) had recently developed a new design for bridge superstructures that utilizes a spread configuration of prestressed concrete slab beams. AASHTO does not contain LDFs for this type of bridge so the load sharing behavior of this superstructure must be investigated further. TxDOT has funded the Texas A&M University Transportation Institute (TTI) to design, model, construct, test, and analyze a full scale spread slab beam bridge. In addition to this testing, an existing slab beam bridge in Denison, Texas will be instrumented and observed for supplementary slab beam behavior data. To predict bridge behavior, computer models of the Riverside experimental bridge and of the Denison field bridge were developed using both the grillage and finite element methods of analysis. The experimental results from the Riverside and Denison bridges will not be collected by the conclusion of this thesis so a third bridge with existing experimental data, the Drehersville, Pennsylvania bridge, was also modeled for calibration purposes. The work presented by this thesis focuses on how to accurately model transverse load distribution relationships and LDFs for use in bridge design. The analysis covered is concentrated primarily on the grillage method, with the finite element analysis as part of the larger project scope. From this analysis it was determined that the grillage method was able to accurately model bridge LDFs as compared to FEM modeling and experimental results, for spread slab beam and spread box beam bridges. The critical loading configurations for all bridges placed two trucks side by side and as far to one edge of the bridge as possible. It was also determined that at an ultimate loading case, the load is distributed much more evenly across the deck than at service loading.

Design and realization of a conventional carbon dioxide laser was performed. Gas composition and gas pressure effects on laser output power were studied. Effects of input electrical power and current on laser power were also investigated. Beam profiling of the laser beam was performed by pinhole method. Laser beam parameters like beam divergence, beam propagation factor were measured. These properties were extracted from focusing a laser beam in near field and performing a number of cuts across the beam cross-section and measuring the beam diameter at these points. Diameter measurements were obtained by knife edge method. Laser beam parameters were obtained for three different power laser beams in two axes across the beam. Found parameters were compared with regard to beam power and beam cross-section axis. Also possibility of using the obtained laser beam in material processing was investigated.

The FONT beam-based, intra-train feedback system has been designed to provide beam position stabilisation in single-pass accelerators. A FONT feedback system utilising position information from three high-resolution cavity beam position monitors (BPMs) has been commissioned at the interaction point (IP) of the Accelerator Test Facility 2 (ATF2) at KEK, Japan. The ultimate goal of the feedback in the IP region is to stabilise the low-emittance electron beam to the nanometre level. The operation, optimisation and resolution performance of this IP system forms the subject of this thesis. The IP feedback system makes use of beam position measurements from the BPMs to drive an upstream kicker and provide a local correction. The BPMs have a fast decay time of ~25 ns to allow bunches within the beam train to be resolved. The operation of the IP BPMs, the noise floor, and position sensitivity to phase are discussed in detail. Attempts are made to diagnose an unwanted ~60 MHz oscillation in the cavity signals, which is bunch charge-dependent and thus likely beam generated. The BPM resolution estimate was notably improved from 50 nm to 20 nm using waveform integration in analysis of the BPM signals. A multi-parameter fit was used to address inaccurate calibrations and charge-dependencies to achieve more consistent resolution performance and produce a best-ever resolution estimate for the BPMs of 17.5 ± 0.4 nm. A novel mode of IP beam position stabilisation using two BPMs as input to the feedback has been successfully demonstrated. The beam position was stabilised to 57 ± 4 nm, as measured at an independent BPM. Feedback performance was improved to this level by sampling the waveform to optimise bunch-to-bunch correlation. Analysis suggests correction capability could be enhanced by firmware waveform integration to achieve a measurable beam stabilisation of ~40 nm in the future.

Concrete is a versatile building material used all over the world. Today's constructions in building and civil engineering have high requirements and complexity that require a carefully executed dimensioning in connection with planning. Calculation programs that work based on standards are a tool for designers in calculation work. Complicated programs or ambiguities in the programs can take up important time, therefore good and clear programs are necessary for time efficiency. This thesis has compared the calculation programs Concrete Beam and Beam EC2, which both are calculation programs used for dimensioning concrete beams. Concrete Beam is used by most constructors in Sweden, while Beam EC2 is a new calculation program that is not used to the same extent. There is therefore a need to evaluate the respective calculation programs in order to increase knowledge in the construction industry about the differences between the calculation programs, as well as to open up the possibility of using more calculation programs in the future. The aim of the thesis is to investigate whether there are differences between Concrete Beam and Beam EC2 when dimensioning a concrete beam. To implement this, the differences in factors such as ease of use, available functions and a calculation result are examined. A smaller sensitivity analysis is also performed to analyze the stability of the calculation programs' values.    The thesis is carried out as a case study with input from a completed reference project by Sweco Sverige AB. The reference project contributes realistic values ​​that are used as input data in the study. The values ​​from the reference project are supplemented with smaller hand calculations for the loads acting on the beam, for example the dead weight and the wind load. This is because values ​​from the reference project are missing. The implementation involves applying the specified values ​​for the inputs from the case study and the hand calculations in the programs. The result shows how each program considers whether the concrete beam can withstand failure and the serviceability limit state, but also how the programs chose to dimension reinforcement in the beam, as well as the result from the sensitivity analysis. Based on the results, a certain difference in the calculation programs could be established, for example how they chose to shape the reinforcement in the beam, which then also led to differences in crack width and deformations. In contrast, the results for the moment and shear force were almost identical. The study also included a sensitivity analysis where Beam EC2 showed stable values ​​while Concrete Beam got a more uncertain result. Based on the results and the sensitivity analysis, the conclusion is that there are clear differences between the calculation programs. The usability is discussed in the opinion of the authors but needs further studies to be used as a general conclusion. The result is limited according to boundaries and the time frame for the work, but there is an opportunity for further studies regarding the differences and usability of the programs in the industry.

Ultrashort pulsed lasers have become critical to understanding light-matter interactions in new regimes such as generation of attosecond pulses, laser filamentation, and intense relativistic processes. Development of more powerful and energetic ultrafast lasers is required for advancing these fields of study. Several petawatt class systems now exist with more in development to further scale peak power and extend the frontier of ultrafast laser technology. Another relevant solution to the scaling of energy and power of ultrashort pulses is coherent beam combining (CBC). CBC is useful for not only scaling of laser parameters but also to mitigate parasitic nonlinear processes associated with high-intensity ultrashort pulses. In addition CBC is flexible and can be implemented as part of other techniques for ultrashort pulse amplification such as optical-parametric chirped-pulse amplification (OPCPA). In this thesis, CBC of ultrashort laser pulses is investigated based upon the method known as divided-pulse amplification (DPA). Active, passive and hybrid DPA have been achieved in a flashlamp-pumped Nd:YAG laser seeded from a Ti:sapphire mode-locked laser. Picosecond pulses at a repetition rate of 2.5 Hz were amplified and combined to record energy of 216 mJ with a combination efficiency of 80%. Engineering of the Nd:YAG amplifier chain for high-efficiency energy extraction is presented. In addition, phasing of actively divided pulses with a CW pilot laser co-propagating with the pulsed beam is also demonstrated. Analysis of multiple DPA configurations shows the viability of the method for a variety of different laser architectures including discussion of design restrictions.