C. Petta

The Data Acquisition and Transport Design for NEMO Phase 1

The NEMO collaboration proposes to build an underwater neutrino telescope located South-East off the Sicily coast. This paper describes the concepts underlying the communication link design going over the whole data acquisition and transport from the front-end electronics to the module sending data on-shore through a fiber optic link which relies on Dense Wavelength Division Multiplexing. An on-shore board, plugged into a PC, extracts and distributes data both to first-level trigger and control systems. Underwater apparatus monitoring and controls are guaranteed by oceanographic instruments and dedicated sensors, whose data are packed and sent back to shore using the same optical link. The communication is fully bidirectional, allowing transmission of timing and control commands. The architecture described here provides a complete real-time data transport layer between the onshore laboratory and the underwater detector. During winter 2006 a first prototype of the apparatus has been deployed: calibration results from the currently working system are here reported.

The design of a system for coloured digital radiology with VLSI circuits and GaAs pixel detectors

AbstractWedescribethedesignofadigitalradiologysystemwithGaAspixeldetectors,basedontheenergyselectionofthenonabsorbedX-ray spectrum.We present ageneral layout; we show that simulationand experimentaldatacorroboratetheidea for the feasibility of the system. ( 1998 Elsevier Science B.V. All rights reserved. 1. IntroductionTheuseof GaAsasahigh-eƒciencyX-rayimag-ing detector is now well known [1].An idea for a novel digital radiology device withinherent high spatial and energy resolution hasbeen proposed [2]. It is based on a GaAs pixeldetector and two custom-made VLSI electroniccircuits which process each photon pulse and clas-sify it according to its energy.The circuits store the counting and the energyinformation, allowing the acquisition of coloured X-ray images. The artiÞcial elaboration of colourcan be performedon line in a scale proportionaltotheenergyofthedetectedphoton.Thescaleresolu-tionwillbelimitedbytheelectroniccircuitsdesign.The method,generallyapplicable,has beenillus-trated before [3]. Here we describe the design fora digital imaging system with an X-ray source,a GaAs pixel detector and the VLSI circuits. Thepaperconcentratesonthegenerallayoutinarealis-tic conÞguration. We address the compromises be-tween the performances of the system, versus thefabrication technologies risks and the costs.WehaveatpresentaÞrstversionofthedetectorswith 32 pixels and the new chip with 8 energyintervals.We show data and compare with the simulationproving that the design idea is well based.2. The basic principleIn radiology, the use of the energy and count-ing information is performed simultaneously in

NEMO: A PROJECT FOR A KM3 UNDERWATER DETECTOR FOR ASTROPHYSICAL NEUTRINOS IN THE MEDITERRANEAN SEA

The status of the project is described: the activity on long term characterization of water optical and oceanographic parameters at the Capo Passero site candidate for the Mediterranean km3 neutrino telescope; the feasibility study; the physics performances and underwater technology for the km3; the activity on NEMO Phase 1, a technological demonstrator that has been deployed at 2000 m depth 25 km offshore Catania; the realization of an underwater infrastructure at 3500 m depth at the candidate site (NEMO Phase 2).