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Microelectronics, telecommunication and controls developments

Final Activity Report Summary - MITELCO (Microelectronics, telecommunication and controls developments)

The MITELCO research projects were mainly concerned with the Large hadron collider (LHC) experiments. Nine Early stage trainings (ESTs) worked on development, installation and commissioning of data acquisition and control systems for the ALICE, ATLAS, CMS and LHCb detectors. Two ESTs developed Application specific integrated circuits (ASICs) for future experiments and one developed firmware for the readout of a detector in LHCb.

The NA62 experiment would study a rare decay mode of the K meson and therefore needed highly segmented (pixel) tracking detectors to measure the time of passage, the trajectory and momentum of particles in a beam of approximately 10^9 particles per sec. Requirements were for timing accuracy of 200 ps, spatial resolution of 100 microns and lossless handling of 1.5M hits/sec/mm2. The timing and hit rate specs were 10 times more demanding than for LHC pixel systems. The chosen architecture used ASICs, each containing a matrix of 40 times 45 pixel cells. The pixels contained simple time-over-threshold logic and transmitted hit signals to end-of-column logic which measured their timing and handled readout. A prototype chip was designed in a 130 nm Complementary metal-oxide semiconductor (CMOS) process.

One technique applied in particle physics measured precise time intervals, e.g. the time of flight of a particle, or electron drift times in gaseous detectors. For such purposes, a multi-channel, large dynamic range time-to-digital conversion (TDC) integrated macro was developed in a 130 nm CMOS process. It used a delay-locked loop technique to generate a stable time base. Dynamic non-linearity was measured as 5.8 ps (rms) and timing precision as 7 ps (rms). A version of the macro was implemented in the NA62 pixel chip.

For the Time projection chamber (TPC) at the LHC heavy ion collision experiment ALICE, Field-programmable gate array (FPGA) based firmware was developed for the readout control unit (RCU). The RCU interfaced a TPC readout partition to the experiment's Data acquisition (DAQ) trigger and Detector control system (DCS). The RCU was made operational in the TPC system and used in successful commissioning tests of the TPC with cosmic rays.

Four ALICE tools were developed for online data quality monitoring. One of them, AMORE, was a fabric of batch processes running on dedicated servers in the DAQ network. It extracted, from raw detector data, high-level physics 'observables' which were accessible by users' code and could be graphically displayed. Considering the detector complexity and the real-time reduction of the event stream by six orders of magnitude, such online tools were indispensible.

Several software modules were developed for the network of approximately 1 600 processors in the ATLAS DAQ system, including an alarm collection and interpretation system as well as an interface to a central monitoring system, a web-based presentation of the status of data-taking and parallel archiving of large data sets acquired on the nodes of the distributed DAQ system. For the Content management system (CMS) data acquisition a 'DAQ configurator' tool was developed and successfully employed in the 2007 commissioning and integration milestones.

For the LHCb DAQ system a network storage system was selected, procured, installed and commissioned. This involved performance evaluation of commercial hardware and development of open source based software for high-speed parallel file writing at speeds of up to 400 MByte/sec.

In ALICE a control system for safe operation of the 100 kV TPC power supplies was developed. To facilitate a homogeneous experiment-wide control system a common standard for finite state machine and user interface tools was defined and supported across all sub-detector groups.

In ATLAS frontend control systems for general equipment infrastructures were prototyped, deployed and commissioned in final versions. They included rack control, environment monitoring and infrared-based safety systems for detecting personnel in the cavern. A control system was provided for beam tests of a luminosity detector. Furthermore, for CMS 'Prozessvisualisierungs- und Steuerungs-System' (PVSS) based controls software was developed to capture detector monitoring data in a database throughout the lifetime of the experiment.

Finally, for LHCb's prototype DAQ system tests PVSS Supervisory control and data acquisition (SCADA) interfaces were developed for the event builder and data sources and a prototype run control system was implemented. A PVSS to ROOT interface was developed for data handling and visualisation.