# Online Program Overview Session: N-38

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## Nuclear Physics Instrumentation I

Session chair: Emilija Pantic U. C. Davis

Shortcut: N-38
Date: Thursday, October 26, 2017, 13:40
Room: Regency VII
Session type: NSS Session

### Contents

1:40 pm N-38-1

#### Test Beam Results and Status of the sPHENIX Calorimeter System(#2999)

M. E. Connors1, 2

1 Georgia State University, Physics and Astronomy, Atlanta, Georgia, United States of America
2 RIKEN BNL Research Center, Brookhaven National Lab, Upton, New York, United States of America

On behalf of the sPHENIX Collaboration

Content

sPHENIX is a planned upgrade to the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). It is designed for precise measurements of jets, heavy-flavor and upsilons in the quark gluon plasma which is created in heavy-ion collisions at RHIC. sPHENIX consists of tracking and calorimeter systems that cover the full $2\pi$ in azimuth and $\pm1$ in psuedo-rapidity. The calorimeter system is composed of an electromagnetic calorimeter and a hadronic calorimeter. The EMCal towers are made of fibers embedded in a tungsten and epoxy mixture. The HCal has alternating layers of steel plates and scintillator tiles. Fibers embedded in the scintillator tiles are read out by SiPMs as is the light collected in the EMCal towers. To test the performance of the calorimeter design, a prototype was built and tested as the T-1044 experiment at the Fermilab Test Beam Facility.  Results from the 2016 test beam demonstrated that the mid-rapidity configuration performed as expected from simulation and satisfied the performance requirements for the sPHENIX program. In February 2017, the high rapidity configuration of the calorimeter prototypes were tested. This includes the 2-dimensional projective EMCal towers. Recent developments and the newest results from the 2017 test beam will be presented.

Keywords: calorimetry
1:58 pm N-38-2

#### Design of a Compact Time Projection Chamber for the sPHENIX Experiment(#2495)

K. Dehmelt1

1 Stony Brook University, Department of Physics and Astronomy, Stony Brook, New York, United States of America

On behalf of the sPHENIX-Collaboration

Content

The sPHENIX detector is being proposed at the Relativistic Heavy Ion Collider to measure jets, jet correlations and Upsilon resonances for advancing our understanding of the Quark-Gluon Plasma formed in heavy ion collisions. It is also expected to form the basis of a day-1 detector for a future U.S. Electron Ion Collider.

sPHENIX is based on a superconducting solenoidal magnet, formerly used by the BaBar experiment, and of charged particle tracking, electromagnetic as well as hadronic calorimetry. It covers a large acceptance, 2π in azimuth and |η| < 1.1 in pseudorapidity and allows to acquire data at a rate of up to 15 kHz.

A Gas Electron Multiplier (GEM) based Time Projection Chamber (TPC) has been proposed for tracking in a high multiplicity environment. The main tasks of this configuration are the achievement of excellent momentum resolution and combating ion back-flow (IBF) which both present a challenge for a compact TPC.

The motivation and the design of the technology choices will be presented along with the present status of ongoing R&D and simulation studies as well as first prototype results. Furthermore, alternative readout structures, like hybrids of various Micropattern Gas Detectors (MPGD) will be discussed.

Keywords: RHIC, TPC, MPGD, GEM, Micromegas, IBF, EIC, QGP
2:16 pm N-38-3

#### Design and Performance of the Readout Electronics for the sPHENIX Calorimeters(#3423)

E. J. Mannel1

1 Brookhaven National Lab, Physics Dept, Upton, New York, United States of America

On behalf of the sPHENIX Collaboration

Content

The sPHENIX collaboration has proposed a major upgrade, sPHENIX, to probe the nature of the Quark-Gluon Plasma, QGP, by studying jets produced in p+p, p+A, and A+A collisions at RHIC. The sPHENIX detector consists of a super-conducting solenoid, formerly the BaBar solenoid, electromagnetic and hadronic calorimetry, and central tracking optimized for jet studies. For sPHENIX electromagnetic and hadronic calorimeters, we have designed an optical readout system based on Silicon Photomultipliers (SiPMs). We have also designed a new 14-bit ADC based digitizer system capable of operating up to 65 MHz and provides a digital pipeline capable of buffering 8 micro-sec of data and up to 5 triggered events. In this paper we will present the current design, along with the performance of the prototype calorimeter electronics and readout chain.

2:34 pm N-38-4

#### Light Collection Efficiency and Uniformity of Light Guides for the sPHENIX Electromagnetic Calorimeter(#3887)

S. Stoll1, D. Cacace1, J. Huang1, Z. Shi2, T. Shimek3, C. Woody1

1 Brookhaven National Laboratoryity, Physics, Upton, New York, United States of America
2 Massachusettes Inst of Technology, Physics, Cambridge, Massachusetts, United States of America
3 Texas State University, Physics, San Marcos, Texas, United States of America

sPHENIX Collaboration

Content

A new electromagnetic calorimeter is being designed for the sPHENIX experiment at RHIC which consists of a tungsten powder and epoxy absorber with embedded scintillating fibers that are read out with SiPMs through short acrylic light guides. The light guides must be as short as possible in order that the calorimeter fit inside the spectrometer magnet of the sPHENIX experiment. In addition, a high degree of segmentation is required in order to measure photons and jets in heavy ion collisions, thus leading to a large number of individual towers with approximately 25K light guides. These requirements present numerous challenges in terms of achieving good light collection efficiency and uniformity from the absorber blocks which is necessary to obtain good energy resolution from the calorimeter. We have tested different versions of simple trapezoidal light guides on prototype calorimeters in beam tests conducted at Fermilab, and also utilized a simulation program to study more complicated light guide geometries and compared them to measurements in the laboratory. We will present the results of these studies and discuss our findings on how to implement an optimal light guide design on the sPHENIX electromagnetic calorimeter.

Keywords: Light Guide, Winston Cone, sPHENIX, sipm, calorimeter
2:52 pm N-38-5

#### The PANDA Barrel DIRC Detector at FAIR(#3179)

M. Krebs1, 2

2 Goethe University, Institute for nuclear physics, Frankfurt, Hesse, Germany

On behalf of the PANDA Cherenkov Group

Content

The Barrel DIRC detector will provide charged particle identification (PID) in the target spectrometer of the PANDA experiment. Its design is based on the successful BABAR DIRC detector with important improvements, such as focusing optics and fast photon timing. Based on extensive R&D efforts, the PANDA Barrel DIRC baseline design using 3 narrow bars per sector with multi-layer spherical lenses and fused silica prisms acting as expansion volume was found to deliver the needed performance for hadronic PID in the target spectrometer of the PANDA experiment. Due to cost constraints, alternative radiator geometries have been investigated in simulations. The best performing candidate is the wide plate, which in fact replaces the 3 narrow bars per sector, offering significant cost-saving potential as the optical industry needs to fab ricate fewer pieces. In order to validate the PANDA Barrel DIRC baseline design and to test the cost-saving option using wide plates, test beam campaigns have been performed at CERN in 2015 and 2016. On this basis a Technical Design Report (TDR) has been submitted in late 2016. The baseline design of the PANDA Barrel DIRC and the validation of the PID performance in particle beams at CERN will be shown in this contribution.

Keywords: Hadron physics, DIRC detectors, Photon sensors
3:10 pm N-38-6

#### Status and perspective of the FARCOS telescope array(#3847)

L. Acosta1, 2, L. Auditore3, 4, C. Boiano5, G. Cardella2, A. Castoldi6, 5, M. D'Andrea2, E. De Filippo2, D. Dell'Aquila7, 8, S. De Luca3, 4, F. Favela2, F. Fichera2, N. Giudice9, 2, B. Gnoffo9, 2, A. Grimaldi2, C. Guazzoni6, 5, G. Lanzalone10, 11, F. Librizzi2, I. Lombardo7, 8, C. Maiolino11, S. Maffessanti6, 5, N. S. Martorana9, 2, S. Norella3, 4, A. Pagano2, E. V. Pagano9, 11, M. Papa2, T. Parsani6, 5, G. Passaro11, S. Pirrone2, G. Politi9, 2, F. Previdi12, 5, L. Quattrocchi9, 2, F. Rizzo9, 11, P. Russotto11, G. Sacca'2, G. M. Salemi2, D. Sciliberto2, A. Trifirò3, 4, M. Trimarchi3, 4, M. Vigilante7, 8

1 Universidad Nacional Autónoma de México, Instituto de Física, Mexico City, Mexico
2 INFN, Sezione di Catania, Catania, Italy
3 Universita’ degli Studi di Messina, Dip. di Scienze MIFT, Messina, Italy
4 INFN, Gruppo Collegato di Messina, Messina, Italy
5 INFN, Sezione di Milano, Milano, Italy
6 Politecnico di Milano, DEIB, Milano, Italy
7 Universita' degli Studi di Napoli Federico II, Dip. Fisica, Napoli, Italy
8 INFN, Sezione di Napoli, Napoli, Italy
9 Universita’ degli Studi di Catania, Dipartimento di Fisica e Astronomia, Catania, Italy
10 Universita' KORE, Facolta' di Ingegneria e Architettura, Enna, Italy
11 INFN, Laboratori Nazionali del Sud, Catania, Italy
12 Universita' degli Studi di Bergamo, Dip. di Ingegneria gestionale, dell'informazione e della produzione, Bergamo, Italy

Content

Few years ago we proposed a novel detection system – named FARCOS (Femtoscopy ARray for COrrelations and Spectroscopy) – to target different open cases in nuclear physics. The basic cluster unit of the FARCOS array is a telescope structure with an active area of 6.4 × 6.4 cm2 composed of three detection stages. The ΔE stages are DC-coupled Double-Sided Silicon Strip Detectors (DSSSDs), 300 μm thick and 1500 μm thick, featuring 32 × 32 orthogonal strips. The third stage, acting as calorimeter, is composed of four truncated pyramids of CsI(Tl) crystals with an active area of 3.2 × 3.2 cm2 and an absorption length of 6 cm arranged in window configuration. The final system will be a modular assembly of 20 telescopes.

A key feature of FARCOS, not present in similar existing correlator systems, is the capability to operate pulse-shape analysis in order to fully identify the particles stopping even in the first detection layer.

The FARCOS frontend electronics has been designed to feature a dynamic range in excess of half GeV with 4 different selectable gain values and an energy resolution of the order of 10 keV FWHM with a power budget of about 10 mW/channel (ASIC only). 16-channel charge preamplifiers are integrated in a single chip. A dedicated 8 layer frontend board houses 2 ASICs and the line-drivers needed to provide a differential output and to drive the several-meter long connections. The performance of the individual components has been extensively qualified together with the performance of few workhorses of the FARCOS clusters in view of the assembly of the final telescopes foreseen for fall 2017.

The presentation will focus on the relevant features of the FARCOS telescope array. The final structure of the FARCOS telescope will be critically revised and the measured performance of the different components will be discussed, with a special focus on their impact on the upcoming measurement campaigns.

Work supported by INFN (NEWCHIM experiment).

Keywords: FARCOS telescope, Correlator, Femtoscopy, Particle identification