ELECTRONICS GROUP AGATA

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1 ELECTRONICS GROUP The CSNSM electronics group activities are mainly related to the construction of nuclear physics instrumentation. The group is involved in the design and the development of detector instrumentation and data acquisition systems. They cover projects from local laboratory needs as well as international collaborations in various European Projects. The group offers complete system construction, starting from the technical project specification definition, including all different design phases and procedures up to full production and system integration inside the experimental areas. Even though the group is answering to most requests, its domain of expertise is in digital electronics design using High-speed data transmission and processing (High density FPGAs, fiber optics, etc.). During the last few years the principal activity of the group has been focused on new R&D project for the S3 (Super Separator Spectrometer) detection system which will be installed at GANIL. Beside the responsibility of the full electronic chain of the tunnel detector instrumentation of S3, the group also ensured upgrades and the maintenance of the Local Level Processing electronics for AGATA (Advanced GAmma Tracking Array). After experiencing several departures in the past, the technical staff structure is capable of handling projects with the help of some quality students. Members: V. Alaphilippe, N. Karkour, L. Gibelin, X. Lafay, D. Linget, B. Travers. AGATA N. Karkour, N. Dosme, X. Grave, L. Gibelin, A. Korichi, X. Lafay, E. Legay, D. Linget, B. Travers. Collaborations : GANIL: E. Clément, C. Michelagnoli, F. Saillant, M. Tripon, IFIC-Valencia: A. Gadéa, STFC-Daresbury: I. Lazarus AGATA is a high-resolution gamma spectrometer using radioactive or high intensity stable beams. It s a 4π detector composed of 180 highly segmented Ge crystals. These segments (36 per crystal) are used to calculate the total energy deposited by a γ ray when it scatters inside the detector. The interaction position of the γ ray is calculated from the shape of the signal. In collaboration with the IPNO and the Padua group (INFN lab), the CSNSM electronics group has participated in the design of the Local level Processing (LLP) electronics which is housed in ATCA format modules. Each module is composed of a carrier motherboard and 4 daughterboards. The electronics group designed the segment and core mezzanine daughterboards used for data processing. AGATA ELECTRONICS ARCHITECTURE The objective of the Front-End Electronics (FEE) is to digitize each signal from crystals and to process them in real time in order to establish the amount of energy deposited by the γ ray in each segment and the total energy in the core contact of the detector. The positions of the interaction points of the γ ray are calculated in the Pulse Shape Analysis (PSA) for which the FEE supplies a short trace of the digitized leading edge of each pulse along with energy and timestamp. The detector signals are 100 MHz (14- bit resolution). Each Digitizer is designed to house the signals of a complete crystal. They are placed near the detector mechanics with no access during the beam run. The digital data are sent to another hall with 2 Gbits/s optical fibers. The (Segment/Core) mezzanine cards receive the digital data, calculate energy, store part of the trace and associate event number and timestamp to the processed data. This buffer is sent to the carrier card housing 4 mezzanines. Two carrier cards are needed to process one complete crystal.

2 OUR CONTRIBUTION After the complete installation of the new phase in the GSI Accelerator (105 mezzanine boards for 15 crystals), several firmware updates were made on the cards for future production purposes. In parallel, a complete test bench, which copies a complete acquisition of a crystal, was used to qualify the FPGA firmware updates inside the mezzanine cards as well as the GSI setup. During 2014, the AGATA experiment moved to GANIL for a new nuclear structure campaign using the beam capabilities of GANIL/SPIRAL2. The group was in charge with the dismantling and the installation of all the LLP system. This task included the optical fiber links installation and all the interconnections setting of the experiment (digitizers, triggers, acquisitions, power supplies ). The group insured full commissioning of the whole system with the collaboration of data acquisition and local teams. Since the beginning of AGATA, we insure full maintenance for the LLP hardware even though these modules were not designed originally by the group. Indeed, the carrier cards were designed in Italy but since 2011, our colleagues could not insure the production of these modules. The CSNSM electronics group was very keen to the scientific results of the project progress, and was aware of the importance of the carrier cards. In this context, the group took the responsibility of the maintenance/operation of the 24 carrier cards needed in 2012 for the GSI phase. This responsibility pushed the project instrumentation capacity from 15 to 25 crystals. The instrumented crystals of AGATA went up from 15 (Legnaro) to 28 (GSI), and this was only possible because of the devotion of the group to handle the 24 carrier card production. Several changes were made to the manufacturing files, and the group faced huge difficulties in purchasing components that become obsolete. In addition, the PCB manufacturing files had to be totally revised, and the production of these cards was a real challenge. All the previous production was made in SnPb process, and this was changed to Pb Free process, which made the production more critical. Despite these difficulties all 24 cards were produced and delivered to GSI and now they all GANIL. AGATA GROUNDING The electronics group is also responsible for ensuring the complete grounding system in AGATA. Measurement campaigns were conducted at LNL, GSI, GANIL and the latest results achieved showed -100 db of noise rejection. In other words, if a transient noise of 4 kv is sent to the system, the effect is only 4 mv, a truly excellent result. It demonstrates that the signal integrity resolution factor in AGATA is 10-4, which means that the signal measurement is extremely precise and sensitive to noise and to EMC. An excellent grounding installation thus ensures an excellent result. REFERENCES : Data-flow coupling and data-acquisition triggers for the PreSPEC-AGATA campaign at GSI, D. Ralet, S. Pietri, Y. Aubert, M. Bellato, D. Bortolato, S. Brambilla, F. Camera, N. Dosme, A. Gadea, J. Gerl, P. Golubev, X. Grave, H. T. Johansson, N. Karkour, A. Korichi, N. Kurz, X. Lafay, E. Legay, D. Linget, N. Pietralla, D. Rudolph, H. Schaffner, O. Stezowski, B. Travers, O. Wieland, and PreSPEC and AGATA collaboration : Jun 2015 Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 8 Figure 1 a) AGATA LLP electronics and optical fibers (X. Lafay). b) EMC GANIL (N. Karkour). CSNSM - Electronics Group 102

3 SIRIUS GANIL D. Linget, V. Alaphilippe, S. Cabaret, L. Gibelin, X. Grave, K. Hauschild, S. Hervé, N. Karkour, X. Lafay, Internships : M. Chidiac, M. Melki, A. Oliva. Collaborations : GANIL: A. Boujrad, Ch. Houarner, L. Legeard, F. Saillant, Ch. Spitael, M. Tripon, IPHC: O. Dorvaux, B. Gall, F. Leblanc, CEA/IRFU: Th. Chaminade, B. Sulignano,. The S3 project is an international collaboration to construct the most powerful spectrometer at GANIL on SPIRAL2 accelerator. The electronics group works on the focal plane detection system called (Spectroscopy Identification of Rare Isotopes Using S3). This system is composed of around 400 channels to be equipped with different detectors (DSSD, Si Tunnel, Tracker and Ge detectors). The group participates in the Front-End Electronics (FEE), the Back-End Electronics (BEE) group and is responsible of the Tunnel acquisition chain, and the EMC requirements and qualifications. The group insures also the technical coordination, and documentation of the project. The group plays an important role in the infrastructure and integration of the instrument (cabling, power supplies, security, etc.). The FEE requirements are to produce a very large dynamic Preamplifier for Si detectors with a very good resolution. In the past 3 years, the group continued an R&D phase to prove the philosophy of a digital feedback CSP (DFCSP). This preamplifier has continuous feedback controlled by a 3-component system (ADC-FPGA-DAC). The system prevents the preamplifier from saturating and calculates the total energy deposited inside the CSP. The general aim of the system is to be able to measure, with great precision, bipolar low energy charges as well as high-resolution High Energy signals. Measuring high-energy particles consists of injecting an opposite charge to desaturate the CSP. The injected value, thanks to the DAC, will indicate the high energy value of the particle. Hence, the physicist will be able to measure precisely the high energy and the low energy decay particles. In parallel, after validation on the first prototype, the team designed the definitive version of the FADC- DAC card. This daughter board, plugged on Numexo2 card, insures the digitization of 4 channels (Flash MHz-14 bits resolution thanks to the EXOGAM2/NEDA collaboration) with the feedback generator 100 MHz-14 bits) for the preamp. The feedback and energy algorithms are based in the FPGA of the Numexo2 card. For the final design of this board, the main goal is to choose good packages for the components to reduce by 50% the size, to be compatible with the mother board requirement. In this vacuum chamber test bench was designed the DFCSP algorithm since 4 years. The high energy which saturates the output of the CSP was measured with an energy resolution of the order of The preliminary results show a FWHM of MeV which saturates the CSP (the CSP 20 MeV). The charge collected inside the CSP was measured through the DFCSP algorithms. This is a tight collaboration between the GANIL and the CSNSM. EXOGAM 2 hardware and firmware were shared with the DFCSP firmware to perform these analyses. This was done with the help of internship students from the excellent collaboration of the CSNSM with the University of MIT (USA) and the University of Lebanon. Figure 2 a) CSNSM electronics and detector test bench (L. Gibelin). b) Alpha spectra obtained using the GANIL-CSNSM charge sensitive preamplifier with the SIRIUS silicon detector developed at the IPHC (K. Hauschild). 103 CSNSM - Electronics Group

4 COCOTE D. Linget, V. Alaphilippe, S. Cabaret, L. Gibelin, X. Grave, C. Hamadache, S. Hervé, N. Karkour, J. Kiener, X. Lafay, V. Tatischeff, Internships : R. Bitar, N. Mina, R. Hokayemet, M. Omran. Collaboration: IPNO-Orsay : J.J. Dormard, B.Y. Ki, E. Rauly, N. de Séréville, E. Wanlinn. The Compton telescope prototype is based on a LaBr3 scintillator (Energy-CSNSM) coupled with a stack of DSSD (track follower-ipno). During the last years, the group was in charge of the integration of the different electronics (developed in the past) to make synchronization and acquisition for this experiment. The main job is the firmware development in the Altera FPGA to transform the MAROC3 test card into a 64-channel data acquisition system. A complete reverse engineering was done on the test board. The second main work is the Virtex6 FPGA Firmware. To do that the group used the help of high level students (last year graduate electrical engineers) REFERENCES : PhD Thesis of A. Gostojic (CSNSM, 2016) Application of artificial neural network in 3D imaging with lanthanum bromide calorimeter, A. Gostojic V. Tatischeff J. Kiener [...] P. Barrillon, Nucl. Instr. Meth. in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment, 787 (2015) CSNSM - Electronics Group 104

5 Publications CONFERENCES Gadea A.,, Bazzacco D., Clément E. Early discussion on the plans for the installation of the FEE at GANIL (2013) CEM à GSI et au GANIL, (Invited talk) Journées techniques AGATA France (2013), Production et test de l électronique de Pre-Processing FEE Production carrier V4.0, (Invited talk) Journées techniques AGATA France (2013), Orsay Pre-Processing Electronic: manufacturing status, (Invited talk) 13 th AGATA Week (2013), GANIL Caen VHDL1 firmware : status and planning, (Invited talk) 13 th Agata Week (2013), GANIL Caen FEE Pre-Processing mezzanine, (Invited talk) Journées techniques AGATA France (2013), Orsay, Status des préamplificateurs et digitisers (upgrade), (Invited talk) Journées techniques AGATA France (2014) Status of the Processing FEE for the Early phase 1 (Hardware and Firmware), (Invited talk) 14 th AGATA Week (2014) Madrid (Spain) Tunnel Electronics: Digital Feedback Preamplifier DFCSP, RoadMAp for SIRIUS Electronics, EMC Definition and Considerations for SIRIUS project, (Invited talk) SIRIUS Workshop (2014), Electronics and DAQ for the SIRIUS project, (Invited talk) S3 Collaboration Workshop (2014), GANIL Caen Nouvelle électronique : état des lieux, Mesures CEM à GANIL, (Invited talk) Journées techniques AGATA France (2014), Grounding measurements at GANIL, (Invited talk) 15 th AGATA Week (2014), GANIL Caen Status of the Processing FEE for the Early phase 1 (Hardware and Firmware), (Invited talk) 15 th AGATA Week (2014), GANIL Caen Status of the ATCA pre-processing FEE Hardware, Firmware and maintenance, (Invited talk) 14 th AGATA Week (2014) Madrid (Spain), Production et test de l électronique de Pre-Processing : hardware et firmware, (Invited talk) Journées techniques AGATA France (2014), Flash ADC and DAC development board, (Invited talk) SIRIUS Workshop (2014), Status et perspective de l électronique de Pre-Processing ATCA : hardware et firmware, (Invited talk) 13 th AGATA Week (2014), EMC considerations, TUNNEL Electronics DFCSP Qualification, RoadMap Construction for SIRIUS, (Invited talk) SIRIUS Kick-off Meeting (2015), Orsay Pre-Processing Elactronic Maintenance (Hardware and Firmware), (Invited talk) 16 th AGATA Week (2015), Valencia (Spain) firmware_tunnel_sirius_2015, (Invited talk) SIRIUS Kick-off Meeting (2015), Orsay Flash ADC and DAC Mezzanine development, (Invited talk) SIRIUS Kick-off Meeting (2015), Linget, D., Etat des lieux de l électronique, (Invited talk) Journées techniques AGATA France (2015), OTHER COMMUNICATIONS Journées techniques AGATA France : Organisateur des journées techniques (2013), Journées techniques AGATA France : Organisateur des journées techniques (2014), SIRIUS Workshop, Organisateur des journées techniques 2014, Journées techniques AGATA France : Organisateur des journées techniques 2014, SIRIUS Kick-off Meeting, Co-Organisateur 2015, Journées techniques AGATA France : Organisateur des journées techniques 2015, 105 CSNSM - Electronics Group