Ibrahimkutty S., Wagener P., Rolo T.D.S., Karpov D., Menzel A., Baumbach T., Barcikowski S., Plech A.

in Scientific Reports, 5 (2015), 16313. DOI:10.1038/srep16313

Abstract

Pulsed-laser assisted nanoparticle synthesis in liquids (PLAL) is a versatile tool for nanoparticle synthesis. However, fundamental aspects of structure formation during PLAL are presently poorly understood. We analyse the spatio-temporal kinetics during PLAL by means of fast X-ray radiography (XR) and scanning small-angle X-ray scattering (SAXS), which permits us to probe the process on length scales from nanometers to millimeters with microsecond temporal resolution. We find that the global structural evolution, such as the dynamics of the vapor bubble can be correlated to the locus and evolution of silver nanoparticles. The bubble plays an important role in particle formation, as it confines the primary particles and redeposits them to the substrate. Agglomeration takes place for the confined particles in the second bubble. Additionally, upon the collapse of the second bubble a jet of confined material is ejected perpendicularly to the surface. We hypothesize that these kinetics influence the final particle size distribution and determine the quality of the resulting colloids, such as polydispersity and modality through the interplay between particle cloud compression and particle release into the liquid.

Riechelmann, Max

Diploma Thesis, Faculty for Computer Science, Karlsruhe Institute of Technology, 2015.

Abstract

NVIDIAs recently presented GPUDirect RDMA technology allows direct communication on the PCIe bus between NVIDIA GPUs and other devices. The ability to bypass main memory and write and read directly into/from the GPU memory is expected to decrease the latency of data tranfer actions. KIRO (KITs InfiniBand remote communication library) is used to provide high-performance communication for control systems at the image beam line of the ANKA synchrotron. To improve the reaction time of control systems and be ready for cameras with throughput of several gigabytes per second, we have modified KIRO to use the GPUDirect RDMA technology. Using this approach we were able to reach throughput rates of 40 GBit/s and could nearly halve the latency. The GPUDirect technology and the updated architecture of KIRO will be presented in this work. The achieved performance and feasability of the integration in the current workflow will be discussed.

 

First assessor: Prof. Dr. Wolfgang Karl
Second assessor: Prof. Dr. Marc Weber

Supervised by Dipl.-Inform. Timo Dritschler,  Dr. Ing. Mario Kicherer

Stevanovic U., Caselle M., Cecilia A., Chilingaryan S., Farago T., Gasilov S., Herth A., Kopmann A., Vogelgesang M., Balzer M., Baumbach T., Weber M.

in IEEE Transactions on Nuclear Science, 62 (2015) 911-918, 7111386. DOI:10.1109/TNS.2015.2425911

Abstract

© 1963-2012 IEEE. High-speed X-ray imaging applications play a crucial role for non-destructive investigations of the dynamics in material science and biology. On-line data analysis is necessary for quality assurance and data-driven feedback, leading to a more efficent use of a beam time and increased data quality. In this article we present a smart camera platform with embedded Field Programmable Gate Array (FPGA) processing that is able to stream and process data continuously in real-time. The setup consists of a Complementary Metal-Oxide-Semiconductor (CMOS) sensor, an FPGA readout card, and a readout computer. It is seamlessly integrated in a new custom experiment control system called Concert that provides a more efficient way of operating a beamline by integrating device control, experiment process control, and data analysis. The potential of the embedded processing is demonstrated by implementing an image-based trigger. It records the temporal evolution of physical events with increased speed while maintaining the full field of view. The complete data acquisition system, with Concert and the smart camera platform was successfully integrated and used for fast X-ray imaging experiments at KIT’s synchrotron radiation facility ANKA.

Rota L., Caselle M., Chilingaryan S., Kopmann A., Weber M.

in IEEE Transactions on Nuclear Science, 62 (2015) 972-976, 7111377. DOI:10.1109/TNS.2015.2426877

Abstract

© 2014 IEEE. We developed a direct memory access (DMA) engine compatible with the Xilinx PCI Express (PCIe) core to provide a high-performance and low-occupancy alternative to commercial solutions. In order to maximize the PCIe throughput while minimizing the FPGA resources utilization, the DMA engine adopts a novel strategy where the DMA address list is stored inside the FPGA and not in the central memory of the host CPU. The FPGA design package is complemented with simple register access to control the DMA engine by a Linux driver. The design is compatible with Xilinx FPGA Families 6 and 7, and operates with the Xilinx PCIe endpoint Generation 1 and 2 with all lane configurations (x1, x2, x4, x8). A multi-engine architecture is also presented, where two x8 lanes cores are used in parallel together with a PCIe bridge, to exploit fully the capabilities of a PCIe Gen2 x16 lanes link. A data throughput of 3461 MBytes/s has been achieved with a single PCIe Gen2 x8 lanes endpoint. If the dual-engine architecture is used, the throughput is increased up to 6920 MBytes/s. The presented DMA is currently used in several experiments at the ANKA synchrotron light source.

Stevanovic U., Caselle M., Cecilia A., Chilingaryan S., Farago T., Gasilov S., Herth A., Kopmann A., Vogelgesang M., Balzer M., Baumbach T., Weber M.

in IEEE Transactions on Nuclear Science (2015). DOI:10.1109/TNS.2015.2425911

Abstract

High-speed X-ray imaging applications play a crucial role for non-destructive investigations of the dynamics in material science and biology. On-line data analysis is necessary for quality assurance and data-driven feedback, leading to a more efficent use of a beam time and increased data quality. In this article we present a smart camera platform with embedded Field Programmable Gate Array (FPGA) processing that is able to stream and process data continuously in real-time. The setup consists of a Complementary Metal-Oxide-Semiconductor (CMOS) sensor, an FPGA readout card, and a readout computer. It is seamlessly integrated in a new custom experiment control system called Concert that provides a more efficient way of operating a beamline by integrating device control, experiment process control, and data analysis. The potential of the embedded processing is demonstrated by implementing an image-based trigger. It records the temporal evolution of physical events with increased speed while maintaining the full field of view. The complete data acquisition system, with Concert and the smart camera platform was successfully integrated and used for fast X-ray imaging experiments at KIT’s synchrotron radiation facility ANKA.

Rota L., Caselle M., Chilingaryan S., Kopmann A., Weber M.

in IEEE Transactions on Nuclear Science (2015). DOI:10.1109/TNS.2015.2426877

Abstract

We developed a direct memory access (DMA) engine compatible with the Xilinx PCI Express (PCIe) core to provide a high-performance and low-occupancy alternative to commercial solutions. In order to maximize the PCIe throughput while minimizing the FPGA resources utilization, the DMA engine adopts a novel strategy where the DMA address list is stored inside the FPGA and not in the central memory of the host CPU. The FPGA design package is complemented with simple register access to control the DMA engine by a Linux driver. The design is compatible with Xilinx FPGA Families 6 and 7, and operates with the Xilinx PCIe endpoint Generation 1 and 2 with all lane configurations (x1, x2, x4, x8). A multi-engine architecture is also presented, where two x8 lanes cores are used in parallel together with a PCIe bridge, to exploit fully the capabilities of a PCIe Gen2 x16 lanes link. A data throughput of 3461 MBytes/s has been achieved with a single PCIe Gen2 x8 lanes endpoint. If the dual-engine architecture is used, the throughput is increased up to 6920 MBytes/s. The presented DMA is currently used in several experiments at the ANKA synchrotron light source.

Rota L., Caselle M., Chilingaryan S., Kopmann A., Weber M.

in 2014 19th IEEE-NPSS Real Time Conference, RT 2014 – Conference Records (2015), 7097561. DOI:10.1109/RTC.2014.7097561

Abstract

© 2014 IEEE. PCI Express (PCIe) is a high-speed serial point-to-point interconnect that delivers high-performance data throughput. KIT has developed a Direct Memory Access (DMA) engine compatible with the Xilinx PCIe core to provide a smart and low-occupancy alternative logic to expensive commercial solutions. In order to maximize the PCIe throughput the DMA engine adopts a new strategy, where the DMA descriptor list is stored inside the FPGA and not in the central memory system. The FPGA design package is complemented with a simple register access to control the DMA engine by a Linux driver. A handshaking sequence between the DMA engine and the Linux driver ensures that no errors occure, even in data transfers of several hundreds of Gigabytes. The design has been tested with Xilinx FPGA Families 6 and 7, and operates with the Xilinx PCIe endpoint generation 1 and 2 with all lane configurations (x1, x2, x4, x8, x16). Data throughput of more than 3.4 GB/s has been achieved with a PCIe Gen 2 ×8 lanes endpoint. The proposed DMA is currently used in several experiments at the ANKA synchrotron light source.

Caselle M., Brosi M., Chilingaryan S., Dritschler T., Judin V., Kopmann A., Mueller A.-S., Raasch J., Smale N.J., Steinmann J., Vogelgesang M., Wuensch S., Siegel M., Weber M.

in 2014 19th IEEE-NPSS Real Time Conference, RT 2014 – Conference Records (2015), 7097535. DOI:10.1109/RTC.2014.7097535

Abstract

© 2014 IEEE. Since a few years Coherent Synchrotron Radiation (CSR) generated by short electron bunches is provided at the ANKA synchrotron light source. To study the THz emission characteristics over multiple revolutions superconducting YBa2Cu3O7-δ (YBCO) thin-film detectors can be used. The intrinsic response time of YBCO thin films is in the order of a few picoseconds only. For fast and continuous sampling of this individual ultra-short terahertz pulses a novel digitizer system has been developed with programmable sampling times in the range of 3 to 100 ps. The Real-time system is based on a heterogeneous FPGA and GPU architecture for on-line pulse reconstruction and evaluations of the peak amplitudes and the time between consecutive bunches. The data is transmitted to a GPU computing node by a fast data transfer link based on a bus master DMA engine connected to PCI express endpoint logic. This new DMA architecture ensures a continuous high data throughput of up to 4 GByte/s. The presented DAQ system is able to resolve the bursting behavior of single bunches even in a multi-bunch environment and to study the bunch-bunch-interactions.

Schultze, Felix

Master thesis, Faculty of Computer Science, Karlsruhe Institute of Technology, 2015.

Abstract

An ever increasing number of large tomographic images is recorded at synchrotron facilities world wide. Due to the drastic increase of data volumes, there is a recent trend to provide data analysis services at the facilities as well. The ASTOR project aims to realize a cloud-based infrastructure for remote data analysis and visualization of tomographic data. A key component is a web-based data browser to select data sets and request a virtual machine for analysis of this data. One of the challenges is to provide a fast preview of 3D volumes but also 3D sequences. Since a standard data sets exceed 10 gigabytes, standard visualization techniques are not feasible and new data reduction techniques have to be developed.

 

First assessor: Prof. Dr.-Ing. Carsten Dachsbacher
Second assessor: Dr. Suren Chilingaryan

Supervised by  Dr. Andreas Kopmann

Smith J.L., Palermo N.A., Theobald J.C., Wells J.D., Heethoff M.

in Journal of Insect Science, 15 (2015). DOI:10.1093/jisesa/iev114

Abstract

© The Author 2015. Male Chrysomya megacephala (F.) blow fly compound eyes contain an unusual area of enlarged dorsal facets believed to allow for increased light capture. This region is absent in females and has been hypothesized to aid in mate tracking in low light conditions or at greater distances. Many traits used in the attraction and capture of mates are allometric, growing at different rates relative to body size. Previous reports concerning C. megacephala eye properties did not include measurements of body size, making the relationship between the specialized eye region and body size unclear. We examined different morphological features of the eye among individuals of varying sizes. We found total eye size scaled proportionately to body size, but the number of enlarged dorsal facets increased as body size increased. This demonstrated that larger males have an eye that is morphologically different than smaller males. On the basis of external morphology, we hypothesized that since larger males have larger and a greater number of dorsally enlarged facets, and these facets are believed to allow for increased light capture, larger males would be active in lower light levels than smaller males and females of equal size. In a laboratory setting, larger males were observed to become active earlier in the morning than smaller males, although they did not remain active later in the evening. However, females followed the same pattern at similar light levels suggesting that overall body size rather than specialized male eye morphology is responsible for increased activity under low light conditions.