D. Tcherniakhovski

Focal-plane detector system for the KATRIN experiment

Abstract The focal-plane detector system for the KArlsruhe TRItium Neutrino (KATRIN) experiment consists of a multi-pixel silicon p-i-n-diode array, custom readout electronics, two superconducting solenoid magnets, an ultra high-vacuum system, a high-vacuum system, calibration and monitoring devices, a scintillating veto, and a custom data-acquisition system. It is designed to detect the low-energy electrons selected by the KATRIN main spectrometer. We describe the system and summarize its performance after its final installation.

Hardware setup for the next generation of 3D Ultrasound Computer Tomography

We describe the second generation of a 3D-Ultrasound Computer Tomography (USCT) system. After we achieved in the first generation a device with sub-wavelength resolution and three imaging modalities (reflection, attenuation, speed of sound) and tested it with static phantoms, we developed a device for in-vivo imaging. In the new system the geometry of transducers and their spatial distribution is optimized in respect to uniformity and high value of: contrast, resolution, and illumination. Furthermore we developed new electronics which allows faster DAQ (≤ 2 min) and contains larger and faster FPGAs to use their processing power for data pre-processing.

Design of the trigger system for the Auger fluorescence detector

The trigger system for the AUGER fluorescence detector is presented. The main goals of the design were low price, high flexibility of the trigger, high reliability and good testability even at remote operation. The simulation of all boards using VHDL tools resulted in a design which is optimal with respect to these goals and highly independent of existing commercial solutions. The large-scale integration of modern FPGAs yielded a massive parallel system for recognition of tracks and suppression of background. The readout and control is carried out by low cost PCs under the LINUX operating system.

FPGA-based DAQ system for multi-channel detectors

In this article a data acquisition (DAQ) system is presented consisting of FPGA-based electronics and an object-oriented readout software that has been developed for the needs of multi-channel detectors. The design goal of the DAQ electronics was to develop an affordable and scalable multi-channel system that is flexible enough to be easily adapted to the experiment requirements. The analog circuitry is integrated on separate analog boards for easy adaptation to different experiments. The heart of the electronics is a hierarchical system of up to 81 FPGAs organized in three layers. It digitizes up to 480 channels with 12 bit ADCs at 10 to 40MHz sampling rate. The electronics are interfaced by a PCI-bridge to a commercial Processor PMC board.

Statistical current monitor for the cosmic ray experiment Pierre Auger

The air fluorescence telescopes are one essential part of the Pierre Auger Project, currently under construction in Argentina. With a pixel camera of 440 photomultiplier tubes the telescopes observe fluorescence light induced by cosmic ray extensive air showers passing through the atmosphere. In this paper we report on a method to monitor the dc anode current in each photomultiplier by statistical analysis of the signal fluctuations. The method has in our case the advantage that we were able to implement it using free resources of FPGA logic; therefore no additional electronics is required. We present details of the current monitor design and its performance measured with a prototype device.

Characterization of an FPGA-based DAQ system in the KATRIN experiment

This article will describe the procedures used to validate and characterize the combined hardware and software DAQ system of the KATRIN experiment. The Mk4 DAQ Electronics is the latest version in a series of field programmable gate array (FPGA)-based electronics developed at the Karlsruhe Institute of Technologys Institute of Data Processing and Electronics (IPE). This system will serve as the primary detector readout in the KATRIN experiment. The KATRIN data acquisition software is a MacOS X application called ORCA (Object-oriented Real-time Control and Acquisition), which includes a powerful scripting language called ORCAScript. This article will also describe how ORCAScript is used in the validation and characterization tests of the Mk4 DAQ electronics system.

Third level trigger for the fluorescence telescopes of the Pierre Auger Observatory

Abstract The trigger system for the Auger fluorescence telescopes is implemented in hard- and software for an efficient selection of fluorescence light tracks induced by high-energy extensive air showers. The algorithm of the third stage uses the multiplicity signal of the hardware for fast rejection of lightning events with above 99% efficiency. In a second step direct muon hits in the camera and random triggers are rejected by analyzing the space–time correlation of the pixels. The trigger algorithm was tested with measured and simulated showers and implemented in the electronics of the fluorescence telescopes. A comparison to a prototype trigger without multiplicity shows the superiority of this approach, e.g. the false rejection rate is a factor 10 lower.

FPGA-based multi-channel DAQ systems with external PCI express link to GPU compute servers

Our group at KIT has been developing data acquisition (DAQ) systems for many years mainly for large physics experiments like the KATRIN neutrino experiment or the Pierre Auger cosmic ray observatory. The DAQ systems were continuously enhanced as new technologies became available. The core of the DAQ systems are field programmable gate arrays (FPGAs). Trigger functions running on the FPGAs select relevant events out of the permanent data stream of the ADCs and pass it over PCI bus to a embedded Linux computer for further analysis and storage. Modern experiments have raising requirements in both data rate and complexity of trigger and analysis function. To achieve a flexible and fast data link we developed a PCI to PCI Express (PCIe) adapter board which can be connected to any PC equipped with a standard PCIe plug-in adapter. We use this adapter to replace the embedded Linux system and to connect external GPU servers directly to the DAQ system. With this powerful data processing facility at the end of the data chain we can run complex third level trigger functions, reconstruction algorithms and analysis calculations. With PCIe as fast data link and GPU computing together with the well established FPGA unit we achieved a substantial enhancement of our DAQ system.

Single photoelectron resolution for the calibration of photomultiplier systems

The Pierre Auger Observatory is a hybrid detector to measure ultra-high energy cosmic rays by an array of 1600 surface detectors and 24 fluorescence telescopes. Every night the response of the telescopes to light from a LED source, distributed through fibers and illuminating the camera, is measured. This relative calibration monitors the response of each pixel and the time stability. The absolute calibration is one way to perform an end-to-end calibration including effects of the UV filter transmittance, losses at the corrector ring elements, mirror reflectivity, shadowing effects of the camera, light collection efficiency, photomultiplier tube (PMT) gain, and the response of the analog and digital electronics. The absolute gain of each PMT is obtained from the variance of the recorded signals and taking into account the single photoelectron resolution (SER) and the bandwidth of the analog electronics. Thus, the knowledge of the SER and the quality parameters of the optics allow us to calculate the sensitivity piece by piece and to cross-check the absolute calibration. This work presents the results of measurements of the single photoelectron spectra recorded on site with our standard setup. The results are consistent with the Monte Carlo simulations of the multiplication processes at each dynode.

A Real-Time Demonstrator for Track Reconstruction in the CMS L1 Track-Trigger System Based on Custom Associative Memories and High-Performance FPGAs

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 high-performance FPGA device.