Sistema multicanal para aquisiç˜ao de dados em um ... - CBPFIndex

Abstract
This work is a contribution to the development of instrumentation for the MonRAt
experiment (acronym for “Atmospheric Radiation Monitor”, in Portuguese), which is a
compact telescope that aims to measure the fluorescence radiation caused by interaction
of ultra-high energy cosmic rays (between 10 18 eV and 10 20 eV ) in the atmosphere. The
experiment uses the multianodic photomultipliers technology (with 64 pixels) as a fluorescence
radiation sensor. The acquisition system developed is composed of hardware,
firmware and software elements. The hardware is composed of 16 FPGA-based data processing
modules developed in CBPF, providing 64 analog input channels, sampling rate
60 MSPS and 128 channels for time interval measuring, with resolution down to 120 ps.
The firmware describes two architectures of logic circuits, which have been developed and
implemented in one FPGA. The acquisition program was developed for Linux, written in
C++ language, using the ROOT framework. It manages the acquisition process, configures
the hardware and receives data through USB ports. Data can be displayed in real time
and can also be saved in text files. All the systems are described, as well as results of the
characterization of the acquisition channels and measurements for gain determining of the
photomultiplier pixels by two different methods: single photoelectron and photostatistic.
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