C. Avanzini

The trigger for K0→π0π0 decays of the NA48 experiment at CERN

The trigger used for the collection of the samples of K0→π0π0 decays in the NA48 experiment at CERN uses a novel pipeline design in order to satisfy the demanding specifications of a high rate kaon beam. The trigger algorithms, architecture and performance are described.

A high-resolution TDC-based board for a fully digital Trigger and Data AcQuisition system in the NA62 experiment at CERN

A time-to-digital converter-based system, to be used for most subdetectors in the high-flux rare-decay experiment NA62 at CERN SPS, was built as part of the NA62 fully digital trigger and data acquisition system in which the TDC Board (TDCB) and a general-purpose motherboard (TEL62) will play a fundamental role. While TDCBs, housing four high-performance time-to-digital converters (HPTDCs), measure hit times from subdetectors, the motherboard processes and stores them in a buffer, produces trigger primitives from different detectors, and extracts only data related to the lowest trigger level decision, once this is taken on the basis of the trigger primitives themselves. The features of the TDCB developed by the Pisa NA62 group are extensively discussed and performance data are presented in order to show its compliance with the experiment requirements.

A Silicon Array for Cosmic-Ray Composition Measurements in CALET

The CALorimetric Electron Telescope (CALET) mission is proposed for a long exposure observation of high energy cosmic rays and gamma radiation, taking advantage of the JEM-EF facility on the International Space Station. The instrument is optimized for the search of nearby sources of acceleration of cosmic ray electrons in the TeV energy range. Its large collection power also allows for precision studies of the elemental composition of VHE nuclei and of their spectral features. The charge identification of the incoming particle is performed by a double-layered array of pixelated silicon sensors, covering a seamless sensitive area of the order of 1 m 2 . The conceptual design of the array and its front-end electronics are presented.

The CALET CHD for determination of nuclear charge

Calorimetric Electron Telescope (CALET) will be a high energy cosmic ray observatory on the Japanese Experimental Module – Exposed Facility of the International Space Station. In addition to electrons and gamma-rays, CALET has an excellent detection capability of cosmic ray nuclei. In order to determine the atomic number of measured nuclei, the CHarge Detector (CHD) is placed on the top of the calorimeter. The CALET-CHD consists of two orthogonal layers of plastic scintillator charge-measuring modules. Each layer is segmented into 14 scintillator paddles (45 cm×3.2 cm×1 cm) for the reduction of back scattering effects. We evaluated the charge resolution of the plastic scintillators with heavy ion accelerators. In this presentation, we will report the design of the CALET-CHD and its nuclei identification capability as inferred from heavy ion beam tests.

The TDC based integrated trigger system of the NA62 experiment at CERN

The main goal of the NA62 experiment is to measure the branching ratio of the K+ ¿ ¿+¿¿¿ decay, collecting O(100) events in two years of data taking. Efficient online selection of interesting events and loss-less readout at high rate will be key issues for such experiment. An integrated trigger and data acquisition system has been designed, where the processing of timing information from the subdetectors is a key element. Only the very first trigger stage will be implemented in hardware, in order to reduce the total rate for the software levels on PC farms. Readout uniformity among different subdetectors and scalability were taken into account in the architecture design.