Probing laser-driven structure formation at extreme scales in space and time

Irradiation of solid surfaces with high intensity, ultrashort laser pulses triggers a variety of secondary processes that can lead to the formation of transient and permanent structures over large range of length scales from mm down to the nano-range. One of the most prominent examples are LIPSS - Laser Induced Periodic Surface Structures. While LIPSS have been a scientific evergreen for of almost 60 years, experimental methods that combine ultrafast temporal with the required nm spatial resolution have become available only recently with the advent of short pulse, short wavelength free electron lasers. Here we discuss the current status and future perspectives in this field by exploiting the unique possibilities of these 4th-generation light sources to address by time-domain experimental techniques the fundamental LIPSS-question, namely why and how laser-irradiation can initiate the transition of a "chaotic" (rough) surface from an aperiodic into a periodic structure.Comment: 13 pages incl. 5 figure

The Adaptive Gain Integrating Pixel Detector at the European XFEL

The Adaptive Gain Integrating Pixel Detector (AGIPD) is an x-ray imager, custom designed for the European x-ray Free-Electron Laser (XFEL). It is a fast, low noise integrating detector, with an adaptive gain amplifier per pixel. This has an equivalent noise of less than 1 keV when detecting single photons and, when switched into another gain state, a dynamic range of more than 10$^4$ photons of 12 keV. In burst mode the system is able to store 352 images while running at up to 6.5 MHz, which is compatible with the 4.5 MHz frame rate at the European XFEL. The AGIPD system was installed and commissioned in August 2017, and successfully used for the first experiments at the Single Particles, Clusters and Biomolecules (SPB) experimental station at the European XFEL since September 2017. This paper describes the principal components and performance parameters of the system.Comment: revised version after peer revie

Megahertz-rate ultrafast X-ray scattering and holographic imaging at the European XFEL

The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, results from the first megahertz-repetition-rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL are presented. The experimental capabilities that the SCS instrument offers, resulting from the operation at megahertz repetition rates and the availability of the novel DSSC 2D imaging detector, are illustrated. Time-resolved magnetic X-ray scattering and holographic imaging experiments in solid state samples were chosen as representative, providing an ideal test-bed for operation at megahertz rates. Our results are relevant and applicable to any other non-destructive XFEL experiments in the soft X-ray range

DRAGoN: Drone for RAdiation detection of Gammas and Neutrons

The Dragon project’s goal is to design, develop and characterize a mobile system composed of an Unmanned Aerial Vehicle, with a Radiation Detection System capable of identifying radioactive contamination spread over an area of a few to tens of square meters. The capability to quickly survey large areas in case of radiation leakages and nuclear disaster is crucial. It saves time, money and protects personnel using remote detection. It represents an innovative solution for the detection and identification of radioactive materials in a specific area. The proposed technology incorporates thermal and fast neutron detectors along with gamma ray detectors. These measurements are complementary: their combined power is expected to improve the system performances. The system compactness and mobility also permits autonomous measurements and navigation and provides a detailed picture of the radiation levels or contamination surrounding the environment. An overview of the DRAGoN status will be presented, starting from the detection system, the electronic and the first tests

Atmega328P-based X-ray Machine Exposure Time Measurement Device with an Android Interface

The purpose of this study was to design an X-ray microcontroller-based ATmega328P microcontroller exposure time measurement device. That can be done by integrating an X-ray detection circuit, analog signal conditioner, ATmega328P microcontroller and Bluetooth module HC-05 to display and control the measurement results on mobile phones Android. The benefits of this research are expected to be able to increase knowledge and expertise in the field of radiology instruments through X-ray machine parameter measurement techniques and assist technicians to calibrate the X-ray exposure time parameters

Repercussões do nível de corte do TSH para 6mu/l na triagem neonatal de hipotireoidismo congênito em Santa Catarina: resultados preliminares

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Departamento de Pediatria