Numerical optimization of spherical variable-line-spacing grating X-ray spectrometers

Operation of an X-ray spectrometer based on a spherical variable-line-spacing grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and spectrometer geometry

Accurate prediction of X-ray pulse properties from a free-electron laser using machine learning

Free-electron lasers providing ultra-short high-brightness pulses of X-ray radiation have great potential for a wide impact on science, and are a critical element for unravelling the structural dynamics of matter. To fully harness this potential, we must accurately know the X-ray properties: intensity, spectrum and temporal profile. Owing to the inherent fluctuations in free-electron lasers, this mandates a full characterization of the properties for each and every pulse. While diagnostics of these properties exist, they are often invasive and many cannot operate at a high-repetition rate. Here, we present a technique for circumventing this limitation. Employing a machine learning strategy, we can accurately predict X-ray properties for every shot using only parameters that are easily recorded at high-repetition rate, by training a model on a small set of fully diagnosed pulses. This opens the door to fully realizing the promise of next-generation high-repetition rate X-ray lasers

Double Excitations in Helium Atoms and Lithium Compounds

This thesis addresses the investigation of doubly excited 2l´nl states in helium atoms and double core excitations in solid lithium compounds. Measurements on He are made in field free environments and under the influence of electric and magnetic fields, using synchrotron based inelastic photon scattering. Cross sections for scattering to singly excited final states are directly determined and compared to theoretical results and are found to be in excellent agreement. Radiative and spin-orbit effects are quantified and are shown to play an important role in the overall characterization of highly excited He states below the N =2 threshold. A dramatic electric field dependence is also observed in the flourecence yield already for relatively weak fields. This signal increase, induced by electric as well as magnetic fields, is interpreted in terms of mixing with states of higher fluorescence branching ratios. Double core excitations at the lithium site in solid lithium compounds are investigated using resonant inelastic x-ray scattering (RIXS). The lithium halides LiF, LiCl, LiBr and LiI are studied as well as the molecular compounds Li2O, Li2CO3 and LiBF4. States with one, as well as both, of the excited electrons localized at the site of the bare lithium nucleus are identified, and transitions which involve additional band excitations are observed. A strong influence of the chemical surrounding is found, and it is discussed in terms of the ionic character of the chemical bond

Double Excitations in Helium Atoms and Lithium Compounds

This thesis addresses the investigation of doubly excited 2l´nl states in helium atoms and double core excitations in solid lithium compounds. Measurements on He are made in field free environments and under the influence of electric and magnetic fields, using synchrotron based inelastic photon scattering. Cross sections for scattering to singly excited final states are directly determined and compared to theoretical results and are found to be in excellent agreement. Radiative and spin-orbit effects are quantified and are shown to play an important role in the overall characterization of highly excited He states below the N =2 threshold. A dramatic electric field dependence is also observed in the flourecence yield already for relatively weak fields. This signal increase, induced by electric as well as magnetic fields, is interpreted in terms of mixing with states of higher fluorescence branching ratios. Double core excitations at the lithium site in solid lithium compounds are investigated using resonant inelastic x-ray scattering (RIXS). The lithium halides LiF, LiCl, LiBr and LiI are studied as well as the molecular compounds Li2O, Li2CO3 and LiBF4. States with one, as well as both, of the excited electrons localized at the site of the bare lithium nucleus are identified, and transitions which involve additional band excitations are observed. A strong influence of the chemical surrounding is found, and it is discussed in terms of the ionic character of the chemical bond

Automatisk återvinningssorterare: En plattform desginad för att sortera glas, plast och metall

This report describes the design and construction of a tilting platform for sorting household waste, limited to plastic, glass, and metal. The platform utilizes a capacitive sensor to identify if an object is placed on the platform, an inductive sensor to detect metal, and a load cell to differentiate between plastic and glass based on their weight difference. The load cell was found to be inaccurate due to sensitivity to physical changes in the environment and sensor placement, leading to inaccurate weight measurements. Relocating the sensors away from the load cell is recommended to improve accuracy. The platform tilts using to two servomotors, which makes the platform tilt in two degrees of freedom. This solution worked as thought out, except for the universal joint having poor quality, resulting in a wobbly motion.Denna rapport beskriver designen och konstruktionen av en vippande plattform för sortering av hushållsavfall begränsat till plast, glas och metall. Plattformen använder en kapacitiv sensor för att identifiera om ett föremål placeras på den, en induktiv sensor för att detektera metall och en lastcell för att skilja mellan plast och glas baserat på deras viktskillnad. Lastcellen visade sig vara opålitlig på grund av dess känslighet för fysiska förändringar i miljön och placeringen av sensorerna, vilket ledde till felaktiga viktmätningar. Det rekommenderas att flytta sensorerna bort från lastcellen för att förbättra noggrannheten. Den lutande funktionen drivs av två servomotorer som var funktionell men hade en ostadig rörelse på grund av dåliga universal joints

Double Excitations in Helium Atoms and Lithium Compounds

This thesis addresses the investigation of doubly excited 2l´nl states in helium atoms and double core excitations in solid lithium compounds. Measurements on He are made in field free environments and under the influence of electric and magnetic fields, using synchrotron based inelastic photon scattering. Cross sections for scattering to singly excited final states are directly determined and compared to theoretical results and are found to be in excellent agreement. Radiative and spin-orbit effects are quantified and are shown to play an important role in the overall characterization of highly excited He states below the N =2 threshold. A dramatic electric field dependence is also observed in the flourecence yield already for relatively weak fields. This signal increase, induced by electric as well as magnetic fields, is interpreted in terms of mixing with states of higher fluorescence branching ratios. Double core excitations at the lithium site in solid lithium compounds are investigated using resonant inelastic x-ray scattering (RIXS). The lithium halides LiF, LiCl, LiBr and LiI are studied as well as the molecular compounds Li2O, Li2CO3 and LiBF4. States with one, as well as both, of the excited electrons localized at the site of the bare lithium nucleus are identified, and transitions which involve additional band excitations are observed. A strong influence of the chemical surrounding is found, and it is discussed in terms of the ionic character of the chemical bond

Automatisk återvinningssorterare: En plattform desginad för att sortera glas, plast och metall

This report describes the design and construction of a tilting platform for sorting household waste, limited to plastic, glass, and metal. The platform utilizes a capacitive sensor to identify if an object is placed on the platform, an inductive sensor to detect metal, and a load cell to differentiate between plastic and glass based on their weight difference. The load cell was found to be inaccurate due to sensitivity to physical changes in the environment and sensor placement, leading to inaccurate weight measurements. Relocating the sensors away from the load cell is recommended to improve accuracy. The platform tilts using to two servomotors, which makes the platform tilt in two degrees of freedom. This solution worked as thought out, except for the universal joint having poor quality, resulting in a wobbly motion.Denna rapport beskriver designen och konstruktionen av en vippande plattform för sortering av hushållsavfall begränsat till plast, glas och metall. Plattformen använder en kapacitiv sensor för att identifiera om ett föremål placeras på den, en induktiv sensor för att detektera metall och en lastcell för att skilja mellan plast och glas baserat på deras viktskillnad. Lastcellen visade sig vara opålitlig på grund av dess känslighet för fysiska förändringar i miljön och placeringen av sensorerna, vilket ledde till felaktiga viktmätningar. Det rekommenderas att flytta sensorerna bort från lastcellen för att förbättra noggrannheten. Den lutande funktionen drivs av två servomotorer som var funktionell men hade en ostadig rörelse på grund av dåliga universal joints

An ultra-high-stability four-axis ultra-high-vacuum sample manipulator

A report on a four-axis ultra-high-stability manipulator developed for use at the Veritas and Species RIXS beamlines at MAX IV Laboratory, Lund, Sweden, is presented. The manipulator consists of a compact, light-weight X-Y table with a stiffened Z tower carrying a platform with a rotary seal to which a manipulator rod holding the sample can be attached. Its design parameters have been optimized to achieve high eigen-frequencies via a light-weight yet stiff construction, to absorb forces without deformations, provide a low center of gravity, and have a compact footprint without compromising access to the manipulator rod. The manipulator system can house a multitude of different, easily exchangeable, manipulator rods that can be tailor-made for specific experimental requirements without having to rebuild the entire sample positioning system. It is shown that the manipulator has its lowest eigen-frequency at 48.5 Hz and that long-term stability is in the few tens of nanometres. Position accuracy is shown to be better than 100 nm. Angular accuracy is in the 500 nrad range with a long-term stability of a few hundred nanoradians