Bochum 2018 – wissenschaftliches Programm

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HK: Fachverband Physik der Hadronen und Kerne

HK 35: Instrumentation XI

HK 35.4: Vortrag

Mittwoch, 28. Februar 2018, 14:45–15:00, Audimax H1

The readout system of the upgraded ALICE TPC — •Lars Bratrud for the ALICE collaboration — Institut für Kernphysik - Goethe Universität, Frankfurt, Germany

With the planned upgrade of the ALICE Time Projection Chamber for operation at Pb-Pb interaction rates of up to 50 kHz, a new continuous readout system based on point-to-point links will be implemented.

A new Front-End Card (FEC) based on 5 SAMPA front-end ASICs has been developed, which allows to read 160 channels from the new GEM-based readout chambers. The data is sent via two radiation hard GigaBit Transceivers (GBTs) to the Common Readout Unit (CRU) in the counting room at a total data transfer rate of 1.1 GB/s per FEC. Data processing will be performed in the CRU: Data decoding, channel mapping, common mode correction, and cluster-finding. One downlink to the FEC is used for control and configuration through a dedicated Slow Control Adapter chip – the GBT-SCA. To monitor the header-less data stream from the FEC, the SAMPA ADC clocks are sent together with the actual data stream. The generation of a synchronization pattern in the SAMPA, triggered by the readout system, ensures correct (global) alignment of the data on all FECs.

Several verification studies have been performed with the new FEC to make sure that it meets the required specifications for resolution, dynamic range, data transfer rate, and reliability. In order to allow early testing of the Front-End Cards without CRU hardware, a temporary readout solution based on the current readout cards of ALICE was developed and parts of this system will be reused in the CRU.