Bergmann T., Balzer M., Bormann D., Chilingaryan S.A., Eitel K., Kleifges M., Kopmann A., Kozlov V., Menshikov A., Siebenborn B., Tcherniakhovski D., Vogelgesang M., Weber M.

in 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2015 (2016), 7581841. DOI:10.1109/NSSMIC.2015.7581841

Abstract

© 2015 IEEE. The EDELWEISS experiment, located in the underground laboratory LSM (France), is one of the leading experiments using cryogenic germanium (Ge) detectors for a direct search for dark matter. For the EDELWEISS-III phase, a new scalable data acquisition (DAQ) system was designed and built, based on the ‘IPE4 DAQ system’, which has already been used for several experiments in astroparticle physics.

Harbaum T., Seboui M., Balzer M., Becker J., Weber M.

in Proceedings – 24th IEEE International Symposium on Field-Programmable Custom Computing Machines, FCCM 2016 (2016) 184-191, 7544775. DOI:10.1109/FCCM.2016.52

Abstract

© 2016 IEEE. Modern high-energy physics experiments such as the Compact Muon Solenoid experiment at CERN produce an extraordinary amount of data every 25ns. To handle a data rate of more than 50Tbit/s a multi-level trigger system is required, which reduces the data rate. Due to the increased luminosity after the Phase-II-Upgrade of the LHC, the CMS tracking system has to be redesigned. The current trigger system is unable to handle the resulting amount of data after this upgrade. Because of the latency of a few microseconds the Level 1 Track Trigger has to be implemented in hardware. State-of-the-art pattern recognition filter the incoming data by template matching on ASICs with a content addressable memory architecture. An implementation on an FPGA, which replaces the content addressable memory of the ASIC, has not been possible so far. This paper presents a new approach to a content addressable memory architecture, which allows an implementation of an FPGA based design. By combining filtering and track finding on an FPGA design, there are many possibilities of adjusting the two algorithms to each other. There is more flexibility enabled by the FPGA architecture in contrast to the ASIC. The presented design minimizes the stored data by logic to optimally utilize the available resources of an FPGA. Furthermore, the developed design meets the strong timing constraints and possesses the required properties of the content addressable memory.

Amstutz C. et al.

in 2016 IEEE-NPSS Real Time Conference, RT 2016 (2016), 7543102. DOI:10.1109/RTC.2016.7543102

Abstract

© 2016 IEEE.A new tracking system is under development for operation in the CMS experiment at the High Luminosity LHC. It includes an outer tracker which will construct stubs, built by correlating clusters in two closely spaced sensor layers for the rejection of hits from low transverse momentum tracks, and transmit them off-detector at 40 MHz. If tracker data is to contribute to keeping the Level-1 trigger rate at around 750 kHz under increased luminosity, a crucial component of the upgrade will be the ability to identify tracks with transverse momentum above 3 GeV/c by building tracks out of stubs. A concept for an FPGA-based track finder using a fully time-multiplexed architecture is presented, where track candidates are identified using a projective binning algorithm based on the Hough Transform. A hardware system based on the MP7 MicroTCA processing card has been assembled, demonstrating a realistic slice of the track finder in order to help gauge the performance and requirements for a full system. This paper outlines the system architecture and algorithms employed, highlighting some of the first results from the hardware demonstrator and discusses the prospects and performance of the completed track finder.

Amstutz C. et al.

in 2016 IEEE-NPSS Real Time Conference, RT 2016 (2016), 7543110. DOI:10.1109/RTC.2016.7543110

Abstract

© 2016 IEEE.The CMS collaboration is preparing a major upgrade of its detector, so it can operate during the high luminosity run of the LHC from 2026. The upgraded tracker electronics will reconstruct the trajectories of charged particles within a latency of a few microseconds, so that they can be used by the level-1 trigger. An emulation framework, CIDAF, has been developed to provide a reference for a proposed FPGA-based implementation of this track finder, which employs a Time-Multiplexed (TM) technique for data processing.

Rota L., Balzer M., Caselle M., Kudella S., Weber M., Mozzanica A., Hiller N., Nasse M.J., Niehues G., Schonfeldt P., Gerth C., Steffen B., Walther S., Makowski D., Mielczarek A.

in 2016 IEEE-NPSS Real Time Conference, RT 2016 (2016), 7543157. DOI:10.1109/RTC.2016.7543157

Abstract

© 2016 IEEE. We developed a fast linear array detector to improve the acquisition rate and the resolution of Electro-Optical Spectral Decoding (EOSD) experimental setups currently installed at several light sources. The system consists of a detector board, an FPGA readout board and a high-Throughput data link. InGaAs or Si sensors are used to detect near-infrared (NIR) or visible light. The data acquisition, the operation of the detector board and its synchronization with synchrotron machines are handled by the FPGA. The readout architecture is based on a high-Throughput PCI-Express data link. In this paper we describe the system and we present preliminary measurements taken at the ANKA storage ring. A line-rate of 2.7 Mlps (lines per second) has been demonstrated.

Hahn S., Muller Y., Hofmann R., Moosmann J., Oktem O., Helfen L., Guigay J.-P., Van De Kamp T., Baumbach T.

in Physical Review A – Atomic, Molecular, and Optical Physics, 93 (2016), 053834. DOI:10.1103/PhysRevA.93.053834

Abstract

© 2016 American Physical Society. ©2016 American Physical Society. We analyze theoretically and investigate experimentally the transfer of phase to intensity power spectra of spatial frequencies through free-space Fresnel diffraction. Depending on λz (where λ is the wavelength and z is the free-space propagation distance) and the phase-modulation strength S, we demonstrate that for multiscale and broad phase spectra critical behavior transmutes a quasilinear to a nonlinear diffractogram except for low frequencies. On the contrary, a single-scale and broad phase spectrum induces a critical transition in the diffractogram at low frequencies. In both cases, identifying critical behavior encoded in the intensity power spectra is of fundamental interest because it exhibits the limits of perturbative power counting but also guides resolution and contrast optimization in propagation-based, single-distance, phase-contrast imaging, given certain dose and coherence constraints.

T. Baumbach, V. Altapova, D. Hänschke, T. dos Santos Rolo, A. Ershov, L. Helfen, T. van de Kamp, J.-T. Reszat, M. Weber, M. Caselle, M. Balzer, S. Chilingaryan, A. Kopmann, I. Dalinger, A. Myagotin, V. Asadchikov, A. Buzmakov, S. Tsapko, I. Tsapko, V. Vichugov, M. Sukhodoev, UFO collaboration

Final report, BMBF Programme: “Development and Use of Accelerator-Based Photon Sources”, 2016

Executive summary

Recent progress in X-ray optics, detector technology, and the tremendous increase of processing speed of commodity computational architectures gave rise to a paradigm shift in synchrotron X-ray imaging. In order to explore these technologies within the two UFO projects the UFO experimental station for ultra-fast X-ray imaging has been developed. Key components, an intelligent detector system, vast computational power, and sophisticated algorithms have been designed, optimized and integrated for best overall performance. New methods like 4D cine-tomography for in-vivo measurements have been established. This online assessment of sample dynamics not only made active image-based control possible, but also resulted in unprecedented image quality and largely increased throughput. Typically 400-500 high-quality datasets with 3D images and image sequences are recorded with the UFO experimental station during a beam time of about 3-4 days.

A flexible and fully automated sample environment and a detector system for a set of up to three complementary cameras has been realized. It can be equipped with commercial available scientific visible-light cameras or a custom UFO camera. To support academic sensor development a novel platform for scientific cameras, the UFO camera framework, has been developed. It is a unique rapid-prototyping environment to turn scientific image sensors into intelligent smart camera systems. All beamline components, sample environment, detector station and the computing infrastructure are seamlessly integrates into the high-level control system “Concert” designed for online data evaluation and feedback control.

As a new element computing nodes for online data assessment have been introduced in UFO. A powerful computing infrastructure based on GPUs and real-time storage has been developed. Optimized reconstruction algorithms reach a throughput of several GB/s with a single GPU server. For scalability also clusters are supported. Highly optimized reconstruction and image processing algorithms are key for real-time monitoring and efficient data analysis. In order to manage these algorithms the UFO parallel computing framework has been designed. It supports the implementation of efficient algorithms as well as the development of data processing workflows based on these. The library of optimized algorithms supports all modalities of operation at the UFO experimental station: tomography laminography and diffraction imaging as well as numerous pre- and post-processing steps.

The results of the UFO project have been reported at several national and international workshops and conferences. The UFO project contributes with developments like the UFO- camera framework or its GPU computing environment to other hard- and software projects in the synchrotron community (e.g. Tango Control System, High Data Rate Processing and Analysis Initiative, Nexus data format, Helmholtz Detector Technology and Systems Initiative DTS). Further follow-up projects base on the UFO results and improve imaging methods (like STROBOS-CODE) or add sophisticated analysis environments (like ASTOR).

The UFO project has successfully developed key components for ultra-fast X-ray imaging and serves as an example for future data intense applications. It demonstrates KIT’s role as technology center for novel synchrotron instrumentation.

Koenig T., Zuber M., Trimborn B., Farago T., Meyer P., Kunka D., Albrecht F., Kreuer S., Volk T., Fiederle M., Baumbach T.

in Physics in Medicine and Biology, 61 (2016) 3427-3442, 3427. DOI:10.1088/0031-9155/61/9/3427

Abstract

© 2016 Institute of Physics and Engineering in Medicine. The x-ray dark-field contrast accessible via grating interferometry is sensitive to features at length scales well below what is resolvable by a detector system. It is commonly explained as arising from small-angle x-ray scattering (SAXS), and can be implemented both at synchrotron beamlines and with low-brilliance sources such as x-ray tubes. Here, we demonstrate that for tube based setups the underlying process of image formation can be fundamentally different. For focal spots or detector pixels that comprise multiple grating periods, we show that dark-field images contain a strong artificial and system-specific component not arising from SAXS. Based on experiments carried out with a nanofocus x-ray tube and the example of an excised rat lung, we demonstrate that the dark-field contrast observed for porous media transforms into a differential phase contrast for large geometric magnifications. Using a photon counting detector with an adjustable point spread function, we confirm that a dark-field image can indeed be formed by an intra-pixel differential phase contrast that cannot be resolved as such due to a dephasing between the periodicities of the absorption grating and the Talbot carpet. Our findings are further corroborated by a link between the strength of this pseudo-dark-field contrast and our x-ray tube’s focal spot size in a three-grating setup. These results must not be ignored when measurements are intended to be reproducible across systems.

Huang D.-Y., Bechly G., Nel P., Engel M.S., Prokop J., Azar D., Cai C.-Y., Van De Kamp T., Staniczek A.H., Garrouste R., Krogmann L., Dos Santos Rolo T., Baumbach T., Ohlhoff R., Shmakov A.S., Bourgoin T., Nel A.

in Scientific Reports, 6 (2016), 23004. DOI:10.1038/srep23004

Abstract

With nearly 100,000 species, the Acercaria (lice, plant lices, thrips, bugs) including number of economically important species is one of the most successful insect lineages. However, its phylogeny and evolution of mouthparts among other issues remain debatable. Here new methods of preparation permitted the comprehensive anatomical description of insect inclusions from mid-Cretaceous Burmese amber in astonishing detail. These “missing links” fossils, attributed to a new order Permopsocida, provide crucial evidence for reconstructing the phylogenetic relationships in the Acercaria, supporting its monophyly, and questioning the position of Psocodea as sister group of holometabolans in the most recent phylogenomic study. Permopsocida resolves as sister group of Thripida + Hemiptera and represents an evolutionary link documenting the transition from chewing to piercing mouthparts in relation to suction feeding. Identification of gut contents as angiosperm pollen documents an ecological role of Permopsocida as early pollen feeders with relatively unspecialized mouthparts. This group existed for 185 million years, but has never been diverse and was superseded by new pollenivorous pollinators during the Cretaceous co-evolution of insects and flowers. The key innovation of suction feeding with piercing mouthparts is identified as main event that triggered the huge post-Carboniferous radiation of hemipterans, and facilitated the spreading of pathogenic vectors.

Rota L., Vogelgesang M., Perez L.E.A., Caselle M., Chilingaryan S., Dritschler T., Zilio N., Kopmann A., Balzer M., Weber M.

in Journal of Instrumentation, 11 (2016), P02007. DOI:10.1088/1748-0221/11/02/P02007

Abstract

© 2016 IOP Publishing Ltd and Sissa Medialab srl.Modern physics experiments produce multi-GB/s data rates. Fast data links and high performance computing stages are required for continuous data acquisition and processing. Because of their intrinsic parallelism and computational power, GPUs emerged as an ideal solution to process this data in high performance computing applications. In this paper we present a high-throughput platform based on direct FPGA-GPU communication. The architecture consists of a Direct Memory Access (DMA) engine compatible with the Xilinx PCI-Express core, a Linux driver for register access, and high- level software to manage direct memory transfers using AMD’s DirectGMA technology. Measurements with a Gen3 x8 link show a throughput of 6.4 GB/s for transfers to GPU memory and 6.6 GB/s to system memory. We also assess the possibility of using the architecture in low latency systems: preliminary measurements show a round-trip latency as low as 1 μs for data transfers to system memory, while the additional latency introduced by OpenCL scheduling is the current limitation for GPU based systems. Our implementation is suitable for real-time DAQ system applications ranging from photon science and medical imaging to High Energy Physics (HEP) systems.