1 ns time to digital converters for the KM3NeT data readout system

• Main Author: Calvo, David
• Format: Conference Proceeding
• Language: English
• Subjects: CHERENKOV COUNTERS; Converters; DATA ACQUISITION SYSTEMS; Field programmable gate arrays; Firmware; Gate arrays; IMPLEMENTATION; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; MEDITERRANEAN SEA; MULTIPARTICLE SPECTROMETERS; NEUTRINO DETECTION; Oversampling; PARTICLE IDENTIFICATION; PHOTOCATHODES; Photomultiplier tubes; PHOTOMULTIPLIERS; Read out systems; READOUT SYSTEMS; RESOLUTION; SCINTILLATION COUNTERS; SPHERES; Synchronism; SYNCHRONIZATION; TELESCOPE COUNTERS; TIME-OF-FLIGHT METHOD
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4902781

The KM3NeT collaboration aims at the construction of a multi-km3 high-energy neutrino telescope in the Mediterranean Sea consisting of thousands of glass spheres (nodes), each of them containing 31 photomultiplier (PMT) of small photocathode area. The readout and data acquisition system of KM3NeT has to collect, treat and send to shore, in an economic way, the enormous amount of data produced by the photomultipliers. For this purpose, 31 high-resolution time-interval measuring channels are implemented on the Field-Programmable Gate Arrays (FPGA) based on Time to Digital Converter (TDC). TDC are very common devices in particles physics experiments. Architectures with low resources occupancy are desirable allowing the implementation of other instrumentation, communication and synchronization systems on the same device. The required resolution to measure both, time of flight and timestamp must be 1 ns. A 4-Oversampling technique with two high frequency clocks is used to achieve this resolution. The proposed TDC firmware is developed using very few resources in Xilinx Kintex-7.