<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">% report CNAF 2019
% defilippo@ct.infn.it
% version 1.0
\documentclass[a4paper]{jpconf}
\usepackage{graphicx}
\usepackage{cite}
\begin{document}
\title{The NEWCHIM activity at CNAF for the CHIMERA and FARCOS devices}
\author{E.~De~Filippo$^1$, G.~Cardella$^1$, E.~Geraci$^{2,1}$, B.~Gnoffo$^{2,1}$,  
        G.~Lanzalone$^{3,6}$, C. Maiolino$^3$, N.S.~Martorana$^{3,4}$, 
        A.~Pagano$^1$, E.V.~Pagano$^3$, 
        M.~Papa$^1$, S.~Pirrone$^{1}$, G.~Politi$^{2,1}$, F.~Rizzo$^{2,3}$, 
        P.~Russotto$^{3}$, A.~Trifir\`o$^{5,1}$, M~Trimarchi$^{5,1}$ }
        
\address{$^1$ INFN Sezione di Catania, Catania, IT}
\address{$^2$ Universit\`a di Catania, Catania, IT}
\address{$^3$ INFN Laboratori Nazionali del Sud, Catania, IT}
\address{$^4$ CSFNSM, Catania, IT}
\address{$^5$ Universit\`a di Messina, Messina, IT}
\address{$^6$ Universit\`a di Enna, Enna, IT}

\ead{defilippo@ct.infn.it}

\begin{abstract}
The CHIMERA 4$\pi$ detector operates at INFN-LNS Catania laboratories by using both stable and radioactive ion beams in the Fermi energy regime (10-100 MeV/A). Recently it has been equipped by the new ancillary and modular Femtoscopy Array for Correlation and Spectroscopy (FARCOS) with the implementation of a new digital electronic front-end. We have used the storage capabilities of the CNAF facility in order to handle the huge increase in data storage evaluated at about 5 TB/day in
the 2018 experiment campaigns.    
\end{abstract}

\section{Introduction}
The CHIMERA 4$\pi$ detector is constituted by 1192 Si-CsI(Tl) telescopes. The first stage of
the telescope is a 300 $\mu$m thick silicon detector followed by a CsI(Tl) crystal, having a 
thickness from 6 to 12 cm in length with photodiode readout. One of the key point of this device is the low threshold for simultaneous mass and charge identifications of particles and light ions, the velocity measurement by Time-of-Flight technique and the Pulse Shape Detection (PSD) aiming to measure the rise time of signals for charged particles stopping in the first Silicon detector layer of the telescopes. The CHIMERA array was designed to study the processes responsible for particle productions in nuclear fragmentation, the reaction dynamics and the isospin degree of freedom. Studies of Nuclear Equation of State (EOS) in asymmetric nuclear matter have been performed both at lower densities with respect to nuclear saturation density, in the Fermi energy 
regime at LNS Catania facilities \cite{def14}, and at high densities in the relativistic heavy ions beams energy domain at GSI \cite{rus16}. The production of Radioactive Ion Beams (RIB) at LNS in the recent years has also opened the use of the 4$\pi$ detector CHIMERA to nuclear structure and clustering studies \cite{acqu16, mar18}. 

FARCOS (Femtoscope ARray for COrrelations and Spectroscopy) is an ancillary and compact multi-detector with high angular granularity and energy resolution for the detection of light charged particles (LCP) and Intermediate Mass Fragments (IMF) \cite{epag16}. It has been designed as an array for particle-particle correlation measurements in order to characterize the time scale and shape of emission sources in the dynamical evolution of heavy ion collisions. The FARCOS array is constituted, in the final project, by 20 independent telescopes. Each telescope is composed by three detection stages: the first $\Delta E$ is a 300 $\mu$m thick DSSSD silicon strip detector with 32x32 strips; the second is a DSSSD, 1500 $\mu$m thick with 32x32 strips; the final stage is constituted by 4 CsI(Tl) scintillators, each one of 6 cm in length. 

\begin{figure}[t]
\begin{center}
\includegraphics[width=0.4\textwidth]{fig1.png}
%\vspace{-0.3cm}
\caption{Photograph of a set of 6 Farcos telescopes assembled and tested with radioactive sources inside the CHIMERA vacuum chamber. On the right is visible one ring of the CHIMERA array.}
\label{fig1}
\end{center}
\end{figure}

A generic and scalable electronic system, covering digitalization, signals readout, synchronization and triggering based on the GET electronics (General Electronics for TPCs) \cite{pol18} has been adopted for FARCOS readout and for the CsI(Tl) readout of CHIMERA. 
The total number of GET channels for the CHIMERA + FARCOS (20 telescopes) devices is around 
6000. The integration of this system has required the development of a new first stage front-end for FARCOS, based on CMOS new preamplifiers for both DSSSD Silicon and CsI(Tl) detector, integrated in a single and compact ASIC board, and the design of a new dual-gain module to fit with the wide dynamical energy ranges expected for the CHIMERA CsI(Tl) detectors \cite{def18, cas18}. A redesign of CHIMERA data acquisition was needed in order to couple the GET digital acquisition with Chimera Silicon detectors readout handled by the analog acquisition on VME bus. 

\section{CNAF support for Newchim}
In the new digital data acquisition we store the sampled signals, thus producing a huge set of raw data. The data rate can be evaluated at 3-5 TB/day in a experiment (without FARCOS). For example the last CHIMERA experiment in 2018 collected a total of 70 TB of data in two weeks of beam time.
Clearly this easily saturates our local disk servers storage capabilities. We use the CNAF as main backup storage center: after data merging and processing, the raw data (signals) are reduced to physical variables in ROOT format, while the original raw data are copied and stored at CNAF. Copy is done in the {\it /storage/gpfs...} storage area in the general purpose tier 1-UI machines by using the Tier 1 infrastructure and middleware software. In the future could be interesting to use also the CPU resources at CNAF in order to run the data merger and signal processing software directly on the copied data. Indeed we expect a significative increase of the storage resources needed when the FARCOS array will be fully operational.           

\section*{References}

\begin{thebibliography}{99}
\bibitem{def14} De Filippo E and Pagano A 2014 {\it Eur. Phys. J. A} {\bf 50} 32
\bibitem{rus16} Russotto P et al. 2016 {\it Phys. Rev. C} {\bf 94}  034608
\bibitem{acqu16} Dell'Aquila D et al. 2016 {\it Phys. Rev. C} {\bf 93}  024611
\bibitem{mar18} Martorana N S et al. 2018 {\it Phys. Lett. B} {\bf 782}  112
\bibitem{epag16} Pagano E V et al. 2016 {\it EPJ Web of Conf.} {\bf 117} 10008
\bibitem{pol18} Pollacco E C et al. 2018 {\it Nucl. Instr. Meth. Phys. Res. A} {\bf 887} 81 
\bibitem{def18} De Filippo E et al., 2018 {\it  Journal of Physics Conference Series} {\bf 1014}
 012003
\bibitem{cas18} A. Castoldi, C. Guazzoni, T. Parsani, 2018 {\it Nuovo Cimento C} {\bf 41} 168
\end{thebibliography}
\end{document}
</pre></body></html>