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A DAQ architecture for a PET system is presented that focuses on modularity, scalability and reusability. The system defines two basic building blocks: data acquisitors and concentrators, which can be replicated in order to build a complete DAQ of variable size. Acquisition modules contain a scintillating crystal and either a position-sensitive photomultiplier (PSPMT) or an array of silicon photomultipliers (SiPM). The detector signals are processed by AMIC, an integrated analog front-end that generates programmable analog outputs which contain the first few statistical moments of the light distribution in the scintillator. These signals are digitized at 156.25 Msamples/s with free-running ADCs and sent to an FPGA which detects single gamma events, extracts position and time information online using digital algorithms, and submits these data to a concentrator module. Concentrator modules collect single events from acquisition modules and perform coincidence detection and data aggregation. A synchronization scheme over data links is implemented that calibrates each link’s latency independently, ensuring that there are no limitations on module mobility, and that the architecture is arbitrarily scalable. Prototype boards with both acquisition and concentration functionality have been built for evaluation purposes. The performance of a small PET system with two detectors based on continuous scintillators is presented. A synchronization error below 50 ps rms is measured, and energy resolutions of 19% and 24% and timing resolutions of 2.0 ns and 4.7 ns FWHM are obtained for PMT and SiPM photodetectors, respectively. [ABSTRACT FROM PUBLISHER]

Abstract: The ATLAS Tile Calorimeter is a sampling detector composed by cells made of iron-scintillator tiles. The calorimeter cell signals are digitized in the front-end electronics and transmitted to the Read-Out Drivers (RODs) at the first level trigger rate. The ROD receives triggered data from up to 9856 channels and provides the energy, phase and quality factor of the signals to the second level trigger. The back-end electronics is divided into four partitions containing eight RODs each. Therefore, a total of 32 RODs are used to process and transmit the data of the TileCal detector. In order to emulate the detector signals in the production and commissioning of ROD modules a board called ROD Injector and Multiplexer Board (RIMBO) was designed. In this paper, the RIMBO main functional blocks, PCB design and the different operation modes are described. It is described the crucial role of the board within the TileCal ROD test-bench in order to emulate the front-end electronics during the validation of ROD boards as well as during the evaluation of the ROD signal reconstruction algorithms. Finally, qualification and performance results for the injection operation mode obtained during the Tile Calorimeter ROD production tests are presented. [ABSTRACT FROM AUTHOR]

A data acquisition system for a positron emission tomograph (PET) based on avalanche photodiode (APD) readout of lutetium oxyorthosilicate (LSO) scintillator crystals is presented. The analog data of each APD are read out by fast analog to digital converters (ADCs) and processed within field programmable gate arrays (FPGAs). The ADCs are continuously sampling with a 80 MHz, low jitter clock, which is synchronous for the whole detector. The main tasks of the FPGAs are pulse detection and extraction of signal timing information from the digitized data stream. The detected signal pulse data are therefore compared to a predefined set of pulse shapes with known phase shifts with respect to the sample clock. By searching for the best match within this calibration set, a precise start time information for the signal pulse can be determined. The calculated time values are then transmitted from the ADC cards via fiber optic links to multiplexer modules which combine the different data streams and can also perform further processing like search for coincident events. Finally, the preprocessed detector data are transmitted from the multiplexers to PCI cards in the image reconstruction computers by gigabit optical links. [ABSTRACT FROM AUTHOR]

An overview of the Dø Central Track Trigger (CTT) for the Tevatron Run 2 program is presented. This newly commissioned system uses information from the Dø Central Fiber Tracker and Preshower Detectors to generate trigger information for the first level of the three-tiered Dø Trigger. The system delivers tracking detector trigger decisions every 132 ns, based on input data flowing at a rate of 475 Gbit per second. Initial results indicate excellent performance of the CTT. First studies of efficiency and trigger performance of the CTT are presented. [ABSTRACT FROM AUTHOR]