Commissioning of the First Insertion Devices on the 1.5 GeV Storage Ring in MAX IV

When installing an insertion device (ID) in a storage ring the electron beam is affected. The positional displacement and angle deflection is called orbit displacement (OD) and higher order effects such as focusing of the electron beam are referred to as linear optics. The ability to perform multiple simultaneous experiments is crucial in a synchrotron light source such as MAX IV. This is impossible to achieve if one ID affects the output of another through the electron beam, making correction for an ID's effect on the beam imperative. This thesis covers the commissioning process of the first ID to be installed in the MAX IV 1.5 GeV storage ring (R1). The OD and linear optics of an elliptically polarised undulator (EPU) was to be compensated for in a feed forward approach. In essence the commissioning should make the ID transparent to the electron beam. A general procedure was developed using MATLAB and other software and libraries by first solving the problem on a model of the ring and then in the real storage ring. The electron orbit was corrected down to 1 micrometer for most settings of the ID which is close to the noise level of the measuring system of the ring. The commissioning is considered successful and the ID is ready for beamline delivery and will be able to run without affecting other beamlines. It was discovered that some magnetic coils performed 25 percent below their specifications, and that the beta beat of the bare R1 was at its worst 15 percent, something that should be improved for optimal performance of the facility.Ett insättningselement på MAX IV är en förutsättning för det ljus man vill skapa, men påverkar elektronerna som far runt i anläggningen negativt - med hjälp av smarta elektromagneter kan detta lösas. MAX IV är en partikelaccelerator i världsklass. I anläggningen i utkanten av Lund swishar elektronerna i ljusets hastighet runt i enorma ringar av vakuumrör. Till skillnad från vad många tror krockas här däremot elektronerna inte mot något och man kollar varken efter antimateria eller Higgspartiklar. Istället är användningsområdet för MAX IV mer likt det för ett vanligt mikroskop. Ordspråket "att se något i ett nytt ljus" kan inte passa bättre än det man gör på MAX IV. Elektronerna som leds runt de två ringarna i anläggningen är som vilken ström som helst och mäts av forskarna i Ampere. Och precis som när man slår på strömbrytaren på väggen hemma kan man använda strömmen till att skapa ljus. Skillnaden är att istället för en glödlampa har man på MAX IV ett så kallat insättningselement. En annan skillnad till glödlampan hemma är att med insättningselementen och den välskötta elektronstrålen kan man inte bara skapa världens skarpaste och starkaste ljus - utan också ljus i nästan vilken färg man vill! Med det producerade ljuset tittar de forskare som kommer till Lund från hela världen närmare på sammansättningen av mediciner och material för att kunna förstå deras egenskaper och hur de kan användas. För att producera detta superskarpa ljus måste störningar på elektronstrålen hållas till ett minimum, något insättningselementen försvårar. I elementen böjs elektronstrålen upp och ner i en svajande bana vilket skapar själva ljuset innan elektronerna enligt design lämnar elementet med samma vinkel och position i höjd- och sidled. Men trots noggrannheten i konstruktionen och installationen av insättningselementet, kan ett så pass litet fel som 0.01 % i styrkan på insättningselementet få ödesdigra konsekvenser: elektronernas bana förändras så pass mycket att de krockar med väggen på röret och ljuset släcks direkt efter det satts igång. Detta dilemma kan som tur är lösas. En elektromagnet placeras före och efter insättningselementet och genom att ändra styrkan på elektromagneterna kan elektronernas bana korrigeras. Kruxet är att elektronstrålen inte kan korrigeras efter den har försvunnit in i sidan av vakuumröret. För varje inställning på insättningselementet (tänk dig dimmerinställningar till glödlampan) måste det i förväg finnas motsvarande styrkor på elektromagneterna så att i samma ögonblick som insättningselementet ändrar sig gör också elektromagneterna det och kompenserar. Denna metod för korrigering kallas feed forward, i kontrast till den vanligare metoden feed back. Med en hel tabell fylld av sådana inställningar kan MAX IV köras utan problem och producera världens skarpaste och starkaste ljus

Wireless Body Area Network for Heart Attack Detection

This article describes a body area network (BAN) for measuring an electrocardiogram (ECG) signal and transmitting it to a smartphone via Bluetooth for data analysis. The BAN uses a specially designed planar inverted F-antenna (PIFA) with a small form factor, realizable with low-fabricationcost techniques. Furthermore, due to the human body's electrical properties, the antenna was designed to enable surface-wave propagation around the body. The system utilizes the user's own smartphone for data processing, and the built-in communications can be used to raise an alarm if a heart attack is detected. This is managed by an application for Android smartphones that has been developed for this system. The good functionality of the system was confirmed in three real-life user case scenarios

Remote Nanoscopy with Infrared Elastic Hyperspectral Lidar

Monitoring insects of different species to understand the factors affecting their diversity and decline is a major challenge. Laser remote sensing and spectroscopy offer promising novel solutions to this. Coherent scattering from thin wing membranes also known as wing interference patterns (WIPs) have recently been demonstrated to be species specific. The colors of WIPs arise due to unique fringy spectra, which can be retrieved over long distances. To demonstrate this, a new concept of infrared (950–1650 nm) hyperspectral lidar with 64 spectral bands based on a supercontinuum light source using ray-tracing and 3D printing is developed. A lidar with an unprecedented number of spectral channels, high signal-to-noise ratio, and spatio-temporal resolution enabling detection of free-flying insects and their wingbeats. As proof of principle, coherent scatter from a damselfly wing at 87 m distance without averaging (4 ms recording) is retrieved. The fringed signal properties are used to determine an effective wing membrane thickness of 1412 nm with ±4 nm precision matching laboratory recordings of the same wing. Similar signals from free flying insects (2 ms recording) are later recorded. The accuracy and the method's potential are discussed to discriminate species by capturing coherent features from free-flying insects

Remote Vegetation Diagnostics in Ghana with a Hyperspectral Fluorescence Lidar

Spectral imaging and lidar methods for the characterization of vegetation are vital for understanding plants and, in turn, food security, biodiversity, and vegetation health in a changing climate. While novel hyperspectral imaging, canopy lidar,and solar-induced fluorescence provide details on species, state, structure, and plant physiology, such data come from different instruments. Thus, post-processing and data fusion struggles with synchronization, spatial overlap, and resolution issues. Especially in the tropical regions of sub-Saharan Africa, these complex, expensive, and bulky instruments remain inaccessible. Here, in Ghana, we have built a low-cost, lightweight, and realistic instrument for simultaneously acquiring hyperspectral data of vegetation fluorescence and canopy structure with perfect spatial overlap. In this paper, we demonstrate the application of the hyperspectral fluorescence lidar for diagnostics and species specificity of locally significant crops. We demonstrate simultaneous range and fluorescence measurements of forest canopy, conducted in full sunlight. Our results indicate that the upper side of the leaves shows a more substantial deviation for stressed plants, whilethe lower side shows greater contrast for plant species. This new and simple tool provides a combined method for hyperspectral classification and assessment of the physiological state while also reporting the vegetation height over ground and its diversity

A biophotonic platform for quantitative analysis in the spatial, spectral, polarimetric, and goniometric domains

Advanced instrumentation and versatile setups are needed for understanding light interaction with biological targets. Such instruments include (1) microscopes and 3D scanners for detailed spatial analysis, (2) spectral instruments for deducing molecular composition, (3) polarimeters for assessing structural properties, and (4) goniometers probing the scattering phase function of, e.g., tissue slabs. While a large selection of commercial biophotonic instruments and laboratory equipment are available, they are often bulky and expensive. Therefore, they remain inaccessible for secondary education, hobbyists, and research groups in low-income countries. This lack of equipment impedes hands-on proficiency with basic biophotonic principles and the ability to solve local problems with applied physics. We have designed, prototyped, and evaluated the low-cost Biophotonics, Imaging, Optical, Spectral, Polarimetric, Angular, and Compact Equipment (BIOSPACE) for high-quality quantitative analysis. BIOSPACE uses multiplexed light-emitting diodes with emission wavelengths from ultraviolet to near-infrared, captured by a synchronized camera. The angles of the light source, the target, and the polarization filters are automated by low-cost mechanics and a microcomputer. This enables multi-dimensional scatter analysis of centimeter-sized biological targets. We present the construction, calibration, and evaluation of BIOSPACE. The diverse functions of BIOSPACE include small animal spectral imaging, measuring the nanometer thickness of a bark-beetle wing, acquiring the scattering phase function of a blood smear and estimating the anisotropic scattering and the extinction coefficients, and contrasting muscle fibers using polarization. We provide blueprints, component list, and software for replication by enthusiasts and educators to simplify the hands-on investigation of fundamental optical properties in biological samples

Lidar as a potential tool for monitoring migratory insects

The seasonal migrations of insects involve a substantial displacement of biomass with significant ecological and economic consequences for regions of departure and arrival. Remote sensors have played a pivotal role in revealing the magnitude and general direction of bioflows above 150 m. Nevertheless, the takeoff and descent activity of insects below this height is poorly understood. Our lidar observations elucidate the low-height dusk movements and detailed information of insects in southern Sweden from May to July, during the yearly northward migration period. Importantly, by filtering out moths from other insects based on optical information and wingbeat frequency, we have introduced a promising new method to monitor the flight activities of nocturnal moths near the ground, many of which participate in migration through the area. Lidar thus holds the potential to enhance the scientific understanding of insect migratory behavior and improve pest control strategies.Fil: Chen, Hui. Nanjing Agricultural University; China. Lund University; SueciaFil: Li, Meng. Lund University; SueciaFil: Månefjord, Hampus. Lund University; SueciaFil: Travers, Paul. Polytech Clermont; FranciaFil: Salvador, Jacobo Omar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Lund University; SueciaFil: Müller, Lauro. Lund University; SueciaFil: Dreyer, David. Lund University; SueciaFil: Alison, Jamie. University Aarhus; DinamarcaFil: Høye, Toke T.. University Aarhus; DinamarcaFil: Hu, Gao. Nanjing Agricultural University; ChinaFil: Warrant, Eric. Lund University; SueciaFil: Brydegaard, Mikkel. Lund University; Suecia. FaunaPhotonics; Dinamarca. Norsk Elektro Optikk; Dinamarc