Francisco Javier Egea Canet
Modern nuclear physics experiments involving fusion-evaporation reactions frequently require the detection of particles (alphas,protons,neutrons) which provide crucial information about the nucleus under study. Some reaction channels involving neutron detection have very low-cross section and require the use of large scintillator arrays which are also sensitive to the gamma-rays, hence, meaning that neutron-gamma discrimination (NGD) techniques must be applied. Besides, due to the high counting rates at which the experiments are carried out and the need of using digital electronics, the NGD is expected to be implemented digitally in the earlier stages in order to decrease the total data throughput which would be mostly produced by the gamma-rays. NGD has been largely used in a wide assortment of neutron detectors (Neutron Wall) using analog electronics employing pulse-shape analysis (PSA) techniques such as the zero cross-over (ZCO) and charge-comparison (CC) methods. Due to the inherent limitations of the analog electronics, an effort is put into moving these PSA methods for NGD to the digital domain using programmable devices such as FPGA, so a higher degree of flexibility and integration can be achieved without losing performance in terms of the discrimination performance. In this paper we analyze the performances, complexity and resources of two widely-used PSA algorithms (Zero-CrossOver and Charge Comparison) in order to implement them using digital electronics based on FPGA. The chosen algorithm will be set in the new-digital electronics of the NEDA (Neutron Detector Array) detector, currently in a development stage. It is expected, by employing this algorithm in an FPGA, to provide a simple mechanism to discard a large amount of gamma-rays while preserving the flexibility and robustness that digital systems offer.
Abderrahman Boujrad (GANIL) Andrea Triossi (CERN) Andrés Gadea (IFIC) Charles Houarner (GANIL) Enrique Sanchis Peris (Universitat de Valencia) Gilles De France (GANIL) Huyuk Tayfun (IFIC) Ian Lazarus (STFC Daresbury Laboratory (GB)) Jaowrski Grzegorz (LNL) Johan Nyberg (Uppsala University) Jose Javier Valiente Dobon (LNL (INFN)) Marcin Jastrzab (Universita dell'Insubria-Unknown-Unknown) Michel Tripon (GANIL) Modamio Victor (Universitet i Oslo) Moszynski Marek (National center for nuclear research, Otwock-Świerk, Poland) Nizamettin Erduran (Istanbul Sabahattin Zaim University) Pär-Anders Söderström (Department of Nuclear and Particle Physics, Uppsala University, Uppsala) Robert Wadsworth (University of York) Sefa Erturk (Physics Department) Vicente Gonzalez Millan (Instituto de Fisica Corpuscular (IFIC) UV-CSIC)