Cieri D. et al.
in Proceedings of Science, 2017-September (2017).
© Copyright owned by the author(s) under the terms of the Creative Commons. A new tracking detector is under development for use by the CMS experiment at the High-Luminosity LHC (HL-LHC). A crucial component of this upgrade will be the ability to reconstruct within a few microseconds all charged particle tracks with transverse momentum above 3 GeV, so they can be used in the Level-1 trigger decision. A concept for an FPGA-based track finder using a fully time-multiplexed architecture is presented, where track candidates are reconstructed using a projective binning algorithm based on the Hough Transform followed by a track fitting based on the linear regression technique. A hardware demonstrator using MP7 processing boards has been assembled to prove the entire system, from the output of the tracker readout boards to the reconstruction of tracks with fitted helix parameters. It successfully operates on one eighth of the tracker solid angle at a time, processing events taken at 40 MHz, each with up to 200 superimposed proton-proton interactions, whilst satisfying latency constraints. The demonstrated track-reconstruction system, the chosen architecture, the achievements to date and future options for such a system will be discussed.
Fedi G., Magazzu G., Palla F., Bilei G.M., Checcucci B., Gentsos C., Magalotti D., Storchi L., Balzer M.N., Tcherniakhowski D., Sander O., Baulieu G., Galbit G.C., Viret S., Modak A., Chowdhury S.R.
in Proceedings of Science, 2017-September (2017).
© Copyright owned by the author(s) under the terms of the Creative Commons. A Real-Time demonstrator based on the ATCA Pulsar-IIB custom board and on the Pattern Recognition Mezzanine (PRM) board has been developed as a flexible platform to test and characterize low-latency algorithms for track reconstruction and L1 Trigger generation in future High Energy Physics experiments. The demonstrator has been extensively used to test and characterize the Track-Trigger algorithms and architecture based on the use of the Associative Memory ASICs and of the PRM cards. The flexibility of the demonstrator makes it suitable to explore other solutions fully based on a high-performance FPGA device.
Losel P., Heuveline V.
in Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 10129 LNCS (2017) 121-128. DOI:10.1007/978-3-319-52280-7_12
© Springer International Publishing AG 2017. Segmenting the blood pool and myocardium from a 3D cardiovascular magnetic resonance (CMR) image allows to create a patient-specific heart model for surgical planning in children with complex congenital heart disease (CHD). Implementation of semi-automatic or automatic segmentation algorithms is challenging because of a high anatomical variability of the heart defects, low contrast, and intensity variations in the images. Therefore, manual segmentation is the gold standard but it is labor-intensive. In this paper we report the set-up and results of a highly scalable semi-automatic diffusion algorithm for image segmentation. The method extrapolates the information from a small number of expert manually labeled reference slices to the remaining volume. While results of most semi-automatic algorithms strongly depend on well-chosen but usually unknown parameters this approach is parameter-free. Validation is performed on twenty 3D CMR images.
Steinmann J.L., Blomley E., Brosi M., Brundermann E., Caselle M., Hesler J.L., Hiller N., Kehrer B., Mathis Y.-L., Nasse M.J., Raasch J., Schedler M., Schonfeldt P., Schuh M., Schwarz M., Siegel M., Smale N., Weber M., Muller A.-S.
in Physical Review Letters, 117 (2016), 174802. DOI:10.1103/PhysRevLett.117.174802
© 2016 American Physical Society. Using arbitrary periodic pulse patterns we show the enhancement of specific frequencies in a frequency comb. The envelope of a regular frequency comb originates from equally spaced, identical pulses and mimics the single pulse spectrum. We investigated spectra originating from the periodic emission of pulse trains with gaps and individual pulse heights, which are commonly observed, for example, at high-repetition-rate free electron lasers, high power lasers, and synchrotrons. The ANKA synchrotron light source was filled with defined patterns of short electron bunches generating coherent synchrotron radiation in the terahertz range. We resolved the intensities of the frequency comb around 0.258 THz using the heterodyne mixing spectroscopy with a resolution of down to 1 Hz and provide a comprehensive theoretical description. Adjusting the electron’s revolution frequency, a gapless spectrum can be recorded, improving the resolution by up to 7 and 5 orders of magnitude compared to FTIR and recent heterodyne measurements, respectively. The results imply avenues to optimize and increase the signal-to-noise ratio of specific frequencies in the emitted synchrotron radiation spectrum to enable novel ultrahigh resolution spectroscopy and metrology applications from the terahertz to the x-ray region.
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
© 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
© 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.
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
© 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.
Amstutz C. et al.
in 2016 IEEE-NPSS Real Time Conference, RT 2016 (2016), 7543110. DOI:10.1109/RTC.2016.7543110
© 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.
Amstutz C. et al.
in 2016 IEEE-NPSS Real Time Conference, RT 2016 (2016), 7543102. DOI:10.1109/RTC.2016.7543102
© 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.
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
© 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.