The AGATA collaboration has a long-standing leadership in the development of front-end electronics for high resolution
γ
-ray spectroscopy using large volume high purity germanium detectors. For two ...decades, the AGATA collaboration has been developing state-of-the-art digital electronics processing with high resolution sampling ADC, high-speed signal transfer and fast readout to a high throughput computing (HTC) farm for on-line pulse shape analysis. The collaboration is presently addressing the next challenge of equipping a 4
π
array with more than 6000 channels in high resolution mode, generating approximately 10 MHz of total trigger requests, coupled to a large variety of complementary instruments. A next generation of front-end electronics, presently under design, is based on industrial products (System on Module FPGA’s), has higher integration and lower power consumption. In this contribution, the conceptual design of the new electronics is presented. The results of the very first tests of the pre-production electronics are presented as well as future perspectives.
Three different Artificial Neural Network architectures have been applied to perform neutron/γ discrimination in neda based on waveform and time-of-flight information. Using the coincident γ-rays ...from agata, we have been able to measure and compare on real data the performances of the Artificial Neural Networks as classifiers. While the general performances are quite similar for the data set we used, differences, in particular related to the computing times, have been highlighted. One of the Artificial Neural Network architecture has also been found more robust to time misalignment of the waveforms. Such a feature is of great interest for online processing of waveforms.
A digital TDC with a reduced number of delay line cells Boujrad, A; Bloyet, D; Tripon, M
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2002, Letnik:
486, Številka:
3
Journal Article
Recenzirano
In nuclear physics experiments, a decision maker named as “trigger” gives a bit pattern which allows the fired detectors identification. As the data acquisition dead time is greater than the time ...between physical events, timing information is essential. We add to the trigger function a Time to Digital Converter (TDC) in order to make a separation between events. The paper describes the architecture chosen for the TDC and illustrates the contribution of each element to the TDC performance. An eight-bit counter is used for the dynamic range of the TDC (in microsecond) associated to a delay line improving the resolution (in nanosecond). The study shows that exploiting the two system clock states (high and low) allows to reduce the number of delay line cells. The Differential Nonlinearity Measurements are given for different resolutions (1, 2 and 5
ns) and illustrate the clock period, the clock duty cycle and the delay line contributions to the TDC performances.
This paper presents the final design and results of the FADC Mezzanine for the EXOGAM (EXOtic GAMma array spectrometer) and NEDA (Neutron Detector Array) detectors. The measurements performed include ...those of studying the effective number of bits, the energy resolution using HP-Ge detectors, as well as timing histograms and n/γ discrimination performance. Finally, the conclusion shows how a common digitizing device has been integrated in the experimental environment of two very different detectors which combine both low-noise acquisition and fast sampling rates. Not only the integration fulfilled the expected specifications on both systems, but it also showed how a study of synergy between detectors could lead to the reduction of resources and time by applying a common strategy.
This paper presents the design of the NEDA (Neutron Detector Array) electronics, a first attempt to involve the use of digital electronics in large neutron detector arrays. Starting from the ...front-end modules attached to the PMTs (PhotoMultiplier Tubes) and ending up with the data processing workstations, a comprehensive electronic system capable of dealing with the acquisition and pre-processing of the neutron array is detailed. Among the electronic modules required, we emphasize the front-end analog processing, the digitalization, digital pre-processing and communications firmware, as well as the integration of the GTS (Global Trigger and Synchronization) system, already used successfully in AGATA (Advanced Gamma Tracking Array). The NEDA array will be available for measurements in 2016.
En physique nucléaire, l'interaction faisceau-cible engendre une multitude d'événements qui ne sont pas tous d'intérêt pour le phénomène physique étudié. Il est donc important de disposer d'un ...système de sélection nommé trigger. Nous avons étudié et réalisé un nouveau trigger adapté aux expériences menées au GANIL. Nous avons présenté un historique des différents triggers utilisés aux GANIL (Grand Accélérateur National d'Ions Lourds) et avons montré la nécessité d'un nouveau trigger modulaire, universel et ouvert. Après une description des différents modes de fonctionnement du nouveau trigger (GANIL Master Trigger, GMT) nous avons décrit les phases de sa conception et de sa réalisation. Le trigger renseigne sur la configuration des détecteurs temporels, or cette information peut être fondamentale dans le cas où la fenêtre d'analyse du trigger couvre plusieurs périodes du faisceau. Nous avons donc proposé une structure de mesure de temps (Time to Digital Converter, TDC) qui permet de lever cette indétermination. Les contraintes de temps mort, d'intégration et de consommation nous ont conduit à proposer une architecture numérique basée sur un compteur associé à une ligne A Retard (LAR). Des calculs simples ont permis de définir la zone de fonctionnement du TDC. Cette zone dépend du rapport cyclique de l'horloge et des retards de la LAR. Des mesures de Non Linéarité Différentielle (NLD) pour des résolutions différentes (1,2,5 et 10 ns) ont permis d'établir les limites de ce système et de mettre en évidence des solutions d'amélioration de ces caractéristiques.
SIRIUS is a state-of-the-art detector system for nuclear decay spectroscopy that will be mounted at the focal plane of S 3 (Super Separator Spectrometer), which is part of the new SPIRAL2 facility at ...GANIL, Caen in France. Such a system requires high performance as it is dedicated to the study of very exotic nuclei. It is the result of collaboration between GANIL CSNSM, IRFU, and IPHC It is composed of a succession of detectors (Trackers, Silicon detector DSSD and Tunnel plus an array of five clover Germanium detectors). This set-up is mounted in a compact geometry. The energy measurement varies from 50 keV to over 500 MeV with high precision (2 × 10 -3 ) at low energies and 1 % for the detection of heavy ions. A major challenge has been the development of new electronics with a very large dynamic range maintaining an adequate energy resolution for the measured particles (with energies from a few hundred keV up to 500 MeV).
We have developed a new telescope array, dedicated to the study of direct reactions of exotic nuclei on light targets in inverse kinematics. This device, called MUST2, is briefly described, and the ...results of the first tests performed with an alpha source and Ni beams at 10 and 75 MeV/u on a CDH target are presented.
The new GANIL data acquisition system Boujrad, A.; Saillant, F.
2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149),
2000, Letnik:
2
Conference Proceeding
We report on the new GANIL DAQ system based on VXI-C crates and electronic modules (trigger, converters, scalers...) with a complete software running under LynxOS real-time kernel. The system ...elements can be used in various configurations depending on the type of experiments undertaken by the physicists. Moreover the older electronic subsystems (VXI-D, CAMAC...) can be easily coupled with the newest ones. The easiness of use and the modularity characterize the hardware equipment and the software application. The real-time software is implemented on one or several VME CPUs based on a PowerPC processor. The number of processes can be distributed on these CPUs and are dedicated to a specific job. The data flow is sent by such a task onto the Ethernet 10/100 network using TCP/IP protocol towards the "tapeserver" alpha workstation. This whole "new generation" DAQ system is operational from several months and many experiments have already used it in different configurations.
