Steinmann J.L., Boltz T., Brosi M., Brundermann E., Caselle M., Kehrer B., Rota L., Schonfeldt P., Schuh M., Siegel M., Weber M., Muller A.-S.

in Physical Review Accelerators and Beams, 21 (2018), 110705. DOI:10.1103/PhysRevAccelBeams.21.110705


© 2018 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the. Electron accelerators and synchrotrons can be operated to provide short emission pulses due to longitudinally compressed or substructured electron bunches. Above a threshold current, the high charge density leads to the microbunching instability and the formation of substructures on the bunch shape. These time-varying substructures on bunches of picoseconds-long duration lead to bursts of coherent synchrotron radiation in the terahertz frequency range. Therefore, the spectral information in this range contains valuable information about the bunch length, shape and substructures. Based on the KAPTURE readout system, a 4-channel single-shot THz spectrometer capable of recording 500 million spectra per second and streaming readout is presented. First measurements of time-resolved spectra are compared to simulation results of the Inovesa Vlasov-Fokker-Planck solver. The presented results lead to a better understanding of the bursting dynamics especially above the micro-bunching instability threshold.

Buzmakov A.V., Asadchikov V.E., Zolotov D.A., Roshchin B.S., Dymshits Y.M., Shishkov V.A., Chukalina M.V., Ingacheva A.S., Ichalova D.E., Krivonosov Y.S., Dyachkova I.G., Balzer M., Castele M., Chilingaryan S., Kopmann A.

in Crystallography Reports, 63 (2018) 1057-1061. DOI:10.1134/S106377451806007X


© 2018, Pleiades Publishing, Inc. Abstract: The design of a new automatic X-ray microtomograph is described. The parameters of optical schemes and X-ray detectors in use are presented. Methods for automating experiments, processing tomographic data, and getting access to them are reported.

Funkner S., Brosi M., Briindcrmantr E., Caselle M., Nasse M.J., Niehues G., Rota L., Schonfeldr P., Weber M., Muller A.-S.

in International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz, 2018-September (2018), 8510080. DOI:10.1109/IRMMW-THz.2018.8510080


© 2018 IEEE. At the KArlsruhe Research Accelerator (KARA), we use electro-optical sampling to measures profiles of compressed electron bunches during the microbunching instability. The observation of the complex dynamics of this instability is of special interest because it leads to intense THz radiation bursts. As the revolution frequency of the storage ring is 2.72 MHz, high detection rates are required to record the bunch profiles for every revolution with single-shot measurements. To achieve fast detection rates, we implemented a KIT-developed ultra-fast line array and recorded the electron bunch charge density for every revolution for 3.6 s with a data throughput of 1.4 GBytes/s.

Niehues G., Brosi M., Briindermann E., Casclle M., Funkncr S., Kehrer B., Nasse M.J., Patil M., Rota L., Steinmann J.L., Weber M., Muller A.-S.

in International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz, 2018-September (2018), 8510133. DOI:10.1109/IRMMW-THz.2018.8510133


© 2018 IEEE. A key bottleneck for investigations of ultrafast processes is a detection scheme to record all individual spectra with high repetition rates to avoid averaging and to improve the signal-to-noise ratio. Here, we present spectral measurements of fs laser sources used for electro-optical detection with a KIT-developed linear sensor array and DAQ system adapted to light sources with MHz repetition rates. This system can be equipped with different sensor types covering a broad wavelength range. It can therefore be used for various applications and scientific questions. The presented exemplary applications range from accelerator-based diagnostics to table-top laser experiments.

Kehrer B., Brosi M., Steinmann J.L., Blomley E., Brundermann E., Caselle M., Funkner S., Hiller N., Nasse M.J., Niehues G., Rota L., Schedler M., Schonfeldt P., Schuh M., Schutze P., Weber M., Muller A.-S.

in Physical Review Accelerators and Beams, 21 (2018), 102803. DOI:10.1103/PhysRevAccelBeams.21.102803


© 2018 authors. Published by the American Physical Society. To understand and control dynamics in the longitudinal phase space, time-resolved measurements of different bunch parameters are required. For a reconstruction of this phase space, the detector systems have to be synchronized. This reconstruction can be used for example for studies of the microbunching instability which occurs if the interaction of the bunch with its own radiation leads to the formation of substructures on the longitudinal bunch profile. These substructures can grow rapidly – leading to a sawtooth-like behavior of the bunch. At KARA, we use a fast-gated intensified camera for energy spread studies, Schottky diodes for coherent synchrotron radiation studies as well as electro-optical spectral decoding for longitudinal bunch profile measurements. For a synchronization, a synchronization scheme is used which compensates for hardware delays. In this paper, the different experimental setups and their synchronization are discussed and first results of synchronous measurements presented.

Evangelista Y. et al.

in Journal of Instrumentation, 13 (2018), P09011. DOI:10.1088/1748-0221/13/09/P09011


© 2018 IOP Publishing Ltd and Sissa Medialab. Multi-pixel fast silicon detectors represent the enabling technology for the next generation of space-borne experiments devoted to high-resolution spectral-timing studies of low-flux compact cosmic sources. Several imaging detectors based on frame-integration have been developed as focal plane devices for X-ray space-borne missions but, when coupled to large-area concentrator X-ray optics, these detectors are affected by strong pile-up and dead-time effects, thus limiting the time and energy resolution as well as the overall system sensitivity. The current technological gap in the capability to realize pixelated silicon detectors for soft X-rays with fast, photon-by-photon response and nearly Fano-limited energy resolution therefore translates into the unavailability of sparse read-out sensors suitable for high throughput X-ray astronomy applications. In the framework of the ReDSoX Italian collaboration, we developed a new, sparse read-out, pixelated silicon drift detector which operates in the energy range 0.5-15 keV with nearly Fano-limited energy resolution (≤150 eV FWHM @ 6 keV) at room temperature or with moderate cooling (∼0°C to +20°C). In this paper, we present the design and the laboratory characterization of the first 16-pixel (4 × 4) drift detector prototype (PixDD), read-out by individual ultra low-noise charge sensitive preamplifiers (SIRIO) and we discuss the future PixDD prototype developments.

Blank T., Pfistner P., Leyrer B., Caselle M., Simons C., Schmidt C.J., Weber M.

in 2018 International Conference on Electronics Packaging and iMAPS All Asia Conference, ICEP-IAAC 2018 (2018) 288-292. DOI:10.23919/ICEP.2018.8374306


© 2018 Japan Institute of Electronics Packaging. The Compressed Baryonic Matter Experiment (CBM) investigates highly compressed nuclear matter, utilizing a Silicon Tracking System comprising 896 silicon sensors modules packed in eight layers with an overall area of four sqm. Each module consists of one sensor, 16 Read-Out Chips and 16 double-layer micro flex-cables, which are connected to the top and bottom side of the sensor. The cables are up to 50 cm long. They carry 128 signal traces on two layers at a pitch of 100 μm and a line-width of 25 μm. The layers are separated by a meshed core to reduce the cable capacity to 0.44 pF/cm. The cables are bonded onto one sensor by a pick and place flip-chip machine. The interconnection is realized by gold stud-bumps on the silicon and SAC solder bumps on the cable. The status of the sensor module and cable production process are presented.

Rota L., Caselle M., Brundermann E., Funkner S., Gerth C., Kehrer B., Mielczarek A., Makowski D., Mozzanica A., Muller A.-S., Nasse M.J., Niehues G., Patil M., Schmitt B., Schonfeldt P., Steffen B., Weber M.

in Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (2018). DOI:10.1016/j.nima.2018.10.093


© 2018 Synchrotrons and modern FEL light sources operate with bunch repetition rates in the MHz range. The profile of the electron beam inside the accelerator can be characterized with indirect experimental techniques where linear array detectors are employed to measure the emitted synchrotron radiation or the spectrum of a near-IR laser. To improve the performance of modern beam diagnostics we have developed KALYPSO, a detector system operating with a continuous frame rate of up to 2.7 MHz. To facilitate the integration in different experiments, a modular architecture has been adopted. Different semiconductor micro-strip sensors can be connected to front-end ASICs to optimize the quantum efficiency at different photon energies, ranging from visible light up to near-IR. The front-end electronics are integrated within an heterogeneous DAQ consisting of FPGAs and GPUs, which allows scientists to implement real-time data processing algorithms. The current version of the detector is in operation at the KARA synchrotron light source and at the European XFEL. In this contribution we present the detector architecture, the performance results and the on-going technical developments.

Asadchikov V., Buzmakov A., Chukhovskii F., Dyachkova I., Zolotov D., Danilewsky A., Baumbach T., Bode S., Haaga S., Hanschke D., Kabukcuoglu M., Balzer M., Caselle M., Suvorov E.

in Journal of Applied Crystallography (2018). DOI:10.1107/S160057671801419X


© International Union of Crystallography, 2018 This article describes complete characterization of the polygonal dislocation half-loops (PDHLs) introduced by scratching and subsequent bending of an Si(111) crystal. The study is based on the X-ray topo-tomography technique using both a conventional laboratory setup and the high-resolution X-ray image-detecting systems at the synchrotron facilities at KIT (Germany) and ESRF (France). Numerical analysis of PDHL images is performed using the Takagi–Taupin equations and the simultaneous algebraic reconstruction technique (SART) tomographic algorithm.

Aggleton R. et al.

in Journal of Instrumentation, 12 (2017), P12019. DOI:10.1088/1748-0221/12/12/P12019


© 2017 CERN. A new tracking detector is under development for use by the CMS experiment at the High-Luminosity LHC (HL-LHC). A crucial requirement of this upgrade is to provide the ability to reconstruct all charged particle tracks with transverse momentum above 2-3 GeV within 4 μs 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 combinatorial Kalman Filter. A hardware demonstrator using MP7 processing boards has been assembled to prove the entire system functionality, 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 acceptance at a time, processing events taken at 40 MHz, each with up to an average of 200 superimposed proton-proton interactions, whilst satisfying the latency requirement. The demonstrated track-reconstruction system, the chosen architecture, the achievements to date and future options for such a system will be discussed.