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S. Akkoyun,
A. Algora,
B. Alikhani,
F. Ameil,
G. de Angelis,
L. Arnold,
A. Astier,
A. Ataç,
Y. Aubert,
C. Aufranc, [......],
D. Weisshaar,
D. Wells,
O. Wieland,
A. Wiens,
G. Wittwer,
H. J. Wollersheim,
F. Zocca,
N. V. Zamfir,
M. Ziȩbliński,
A. Zucchiatti
[show abstract]
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ABSTRACT: The Advanced GAmma Tracking Array (AGATA) is a European project to develop
and operate the next generation gamma-ray spectrometer. AGATA is based on the
technique of gamma-ray energy tracking in electrically segmented high-purity
germanium crystals. This technique requires the accurate determination of the
energy, time and position of every interaction as a gamma ray deposits its
energy within the detector volume. Reconstruction of the full interaction path
results in a detector with very high efficiency and excellent spectral
response. The realization of gamma-ray tracking and AGATA is a result of many
technical advances. These include the development of encapsulated
highly-segmented germanium detectors assembled in a triple cluster detector
cryostat, an electronics system with fast digital sampling and a data
acquisition system to process the data at a high rate. The full
characterization of the crystals was measured and compared with
detector-response simulations. This enabled pulse-shape analysis algorithms, to
extract energy, time and position, to be employed. In addition, tracking
algorithms for event reconstruction were developed. The first phase of AGATA is
now complete and operational in its first physics campaign. In the future AGATA
will be moved between laboratories in Europe and operated in a series of
campaigns to take advantage of the different beams and facilities available to
maximize its science output. The paper reviews all the achievements made in the
AGATA project including all the necessary infrastructure to operate and support
the spectrometer.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 11/2011; 668:26. · 1.21 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: An AGATA symmetric, coaxial, high-purity germanium (HPGe) detector has been scanned in coincidence mode. Charge pulse shapes from the 36-fold segmented outer contacts and center contact were stored for events at more than 2000 precisely determined 3-D interaction positions spread over ten depths ( z ). A database (basis) of the 37 average experimental pulse shapes at each position was generated. The electric field simulation code Multi Geometry Simulation (MGS) was used to generate the pulse shapes for the geometry on a 1.0-mm cubic grid. A minimization between the experimental pulse shapes at each position and the MGS basis yielded mean displacements of between 1.5 and 3.0 mm in the x - y plane. The vectors of these displacements were biased in the direction of the center of the detector. This effect is attributed to cross-talk. The maximum level of derivative cross-talk was measured and shown to be 534%ns. However due to the lack of a global clock in the acquisition system, it could not be accounted for throughout the basis.
IEEE Transactions on Nuclear Science 09/2009; · 1.45 Impact Factor
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Q. T. Doan,
D. Curien,
O. Stezowski,
J. Dudek,
K. Mazurek,
A. Gozdz,
J. Piot,
G. Duchene,
B Gall,
H. Molique, [......],
A. Maj,
K Zuber,
P. Bednarczyk,
N. Schunck,
J. Dobaczewski,
A. Astier,
I Deloncle,
D. Verney,
G De Angelis,
J. Gerl
[show abstract]
[hide abstract]
ABSTRACT: Theoretical predictions suggest the presence of tetrahedral symmetry as an explanation for the vanishing intra-band E2-transitions at the bottom of the odd-spin negative parity band in $^{156}Gd$. The present study reports on experiment performed to address this phenomenon. It allowed to determine the intra-band E2 transitions and branching ratios B(E2)/B(E1) of two of the negative-parity bands in $^{156}Gd$.
12/2008;
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M. Bellato,
L. Berti,
D. Bortolato,
P.J. Coleman-Smith,
P. Edelbruck,
X. Grave,
R. Isocrate,
I. Lazarus,
D. Linget, P. Medina,
C. Oziol,
G. Rampazzo,
C. Santos,
B. Travers,
A. Triossi
[show abstract]
[hide abstract]
ABSTRACT: AGATA is a 4-pi array of high purity Ge detectors for in-beam gamma-ray spectroscopy based on the novel concepts of pulse shape analysis (PSA) and gamma-ray tracking. Tracking and PSA require the concurrent digitization-at a sampling rate of 100 Msamples/s-of preamplifier signals of the 36-fold segmented Ge crystals composing the array. Locally digitized data are optically transferred to remote pre-processing nodes for pulse energy computation. The design of the front-end readout and level-1 (L1) trigger in AGATA follows a synchronous pipeline model: the detector data are stored in pipeline buffers at the global AGATA frequency, waiting the global L1 decision. A global timing system provides a reference clock and time tag to the digitizers and the pre-processing units by means of a tree of optically connected timing units. Pre-processing nodes are integrated in advanced TCA-based carrier cards with full mesh connectivity in the backplane and read-out through pci-express based optical links. The front-end data readout and its integration in the global trigger and synchronization system will be described.
IEEE Transactions on Nuclear Science 03/2008; · 1.45 Impact Factor
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M. R. Dimmock,
A. J. Boston,
H. C. Boston,
J. R. Cresswell,
L. Nelson,
P. Nolan,
S. Rigby,
C. Unsworth,
I. Lazarus,
J. Simpson, P. Medina,
C. Parisel,
C. Santos
[show abstract]
[hide abstract]
ABSTRACT: The Advanced GAmma Tracking Array (AGATA) is a European project that is aiming to construct a complete 4π High Purity Germanium (HPGe) gamma-ray spectrometer for nuclear structure studies at future Radioactive Ion Beam (RIB) Facilities. The proposed array will utilise digital electronics, Pulse Shape Analysis (PSA) and Gamma-Ray Tracking (GRT) algorithms, to overcome the limited efficiencies encountered by current Escape Suppressed Spectrometers (ESS), whilst maintaining the high Peak-to-Total ratio. Two AGATA symmetrical segmented Canberra Eurisys (CE) prototype HPGe detectors have been tested at the University of Liverpool. A highly collimated Cs-137 (662keV) beam was raster scanned across each detector and data were collected in both singles and coincidence modes. The charge sensitive preamplifier output pulse shapes from all 37 channels (one for each of the 36 segments and one for the centre contact) were digitised and stored for offline analysis. The shapes of the real charge and image charge pulses have been studied to give detailed information on the position dependent response of each detector. 1mm position sensitivity has been achieved with the parameterisation of average pulse shapes, calculated from data collected with each of the detectors. The coincidence data has also been utilised to validate the electric field simulation code Multi Geometry Simulation (MGS). The precisely determined 3D interaction positions allow the comparison of experimental pulse shapes from single site interactions with those generated by the simulation. It is intended that the validated software will be used to calculate a basis data set of pulse shapes for the array, from which any interaction site can be determined through a χ2 minimisation of the digitized pulse with linear combinations of basis pulseshapes. The results from this partial validation, along with those from the investigation into the position sensitivity of each detector are presented.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
09/2007;
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[show abstract]
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ABSTRACT: A new method to determine the positions and energies of the γ-interactions in a segmented HPGe crystal of the AGATA detector is presented. The procedure is able to decompose multi-hit events, even if hits occur in the same segment. We tested the method with simulated signals; noise and the finite bandwidth of the preamplifier have been considered.
IEEE Transactions on Nuclear Science 07/2006; · 1.45 Impact Factor
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L. Arnold,
R. Baumann,
E. Chambit,
M. Filliger,
C. Fuchs,
C. Kieber,
D. Klein, P. Medina,
C. Parisel,
M. Richer,
C. Santos,
C. Weber
[show abstract]
[hide abstract]
ABSTRACT: We report on the development of Tracking Numerical Treatment (TNT) boards, which are the basic bricks of a more ambitious data acquisition system intended for online data acquisition and treatment in future European experiments. The module makes extensive use of field programmable gate arrays (FPGA) for signal deconvolution and energy calculation with a minimum of data loss. Four channels can be processed simultaneously. Event collection is performed through a fast universal serial bus (USB2). The system can sustain an event rate of 100 kHz without dead time. Here we describe the practical implementation of pulse processing algorithms in a digital electronic module based on high density FPGAs for event processing. The overall system and its architecture are portrayed, along with some technical characteristics. Finally, we present some results and future developments.
IEEE Transactions on Nuclear Science 07/2006; · 1.45 Impact Factor
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A Gadea,
N Marginean,
L Corradi,
S M Lenzi,
C A Ur,
E Farnea,
G de Angelis,
E Fioretto,
D R Napoli,
A M Stefanini, [......],
D Curien, P Medina,
M Chambit,
R Chapman,
X Liang,
S J Freeman,
A Smith,
B J Varley,
V Pucknell,
R Lemmon
[show abstract]
[hide abstract]
ABSTRACT: CLARA is an array of 25 Clover (EUROBALL type) Ge detectors, placed at the target position of the large acceptance magnetic spectrometer PRISMA. Due to the granularity of the CLARA Ge array (100 crystals), the photopeak efficiency (≈3%) and the PRISMA large acceptance (≈80 msr, and 20% Δp/p), the setup is an excellent tool to investigate the structure of neutron-rich nuclei, populated in multinucleon transfer reactions and deep inelastic collisions with stable beams. Since March 2004 the setup is fully operational, and since then several experiments have been performed, with beams delivered by the LNL XTU-Tandem and the ALPI linac. In this contribution the preliminary outcome of the first experiments is shown.
Journal of Physics G Nuclear and Particle Physics 09/2005; 31(10):S1443. · 4.18 Impact Factor
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L. Arnold,
R. Baumann,
E. Chambit,
M. Filliger,
C. Fuchs,
C. Kieber,
D. Klein, P. Medina,
C. Parisel,
M. Richer,
C. Santos,
C. Weber
[show abstract]
[hide abstract]
ABSTRACT: In order to perform a spectroscopy system, typical digital systems consisted of several DSP and a flash ADC. Nowadays FPGAs are well suited for this, since it is possible to implement various tasks running in parallel in a single FPGA device. Here we describe the practical implementation of preprocessing algorithms on a digital electronic module featuring one only FPGA for event processing. The overall system and its functionalities are presented, and then we report some results and future developments
Real Time Conference, 2005. 14th IEEE-NPSS; 07/2005
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[show abstract]
[hide abstract]
ABSTRACT: AGATA is presently one of the world main detector projects for nuclear physics. It is the first real 4pi gamma-ray spectrometer and consists of segmented Germanium detectors. It is based on the novel technique of pulse shape analysis allowing for the tracking of the gamma-rays inside the detector. Thanks to the resulting determination of the gamma emission direction, the effective granularity is expected to be greater than 5 times 10<sup>4</sup> and the energy resolution better than 0.5% for transitions emitted by nuclei recoiling at velocities as high as c/2. The PSA is presently considered as the bottle neck of the project. It must allow the determination of the 3D hit locations with high accuracy even in the case of multiple interactions in the same segment. This is achieved by considering the net charge signal and the induced image signals of the neighboring segments. In multi hit cases, the algorithm must decompose the signals into their individual components in real time (some ms). A microprocessor farm, whose size depends on the time performance of our algorithm, is dedicated to the PSA
Real Time Conference, 2005. 14th IEEE-NPSS; 07/2005
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A. Gadea,
D.R. Napoli,
G. Angelis,
R. Menegazzo,
A.M. Stefanini,
L. Corradi,
M. Axiotis,
L. Berti,
E. Fioretto,
T. Kroell, [......],
S.J. Freeman,
A. Smith,
B. Varley,
K. Fayz,
V. Pucknell,
J. Simpson,
W. Gelletly,
P. Regan,
The EUROBALL,
Collaboration
[show abstract]
[hide abstract]
ABSTRACT: Following the commissioning of the PRISMA large-acceptance spectrometer, installed at the Laboratori Nazionali di Legnaro (LNL), an international nuclear-structure collaboration has started to develop a large
g\gamma
-ray setup to be installed in the target position of the spectrometer. The array is based on the EUROBALL composite CLOVER detectors. In this contribution the CLOVER detector array is described and its expected performance figures discussed. This new setup, by using the high-intensity heavy-ion beams provided by the LNL ALPI linac, will push the study of nuclear structure towards moderately neutron-rich nuclei by means of quasi-elastic and deep inelastic reactions.
European Physical Journal A 03/2003; 20(1):193-197. · 2.19 Impact Factor
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A Gadea,
DR Napoli,
G de Angelis,
R Menegazzo,
AM Stefanini,
L Corradi,
M Axiotis,
L Berti,
E Fioretto,
T Kroell, [......],
J Durell,
SJ Freeman,
A Smith,
B Varley,
K Fayz,
V Pucknell,
J Simpson,
W Gelletly,
P Regan,
EUROBALL PRISMA-2 Collaborat
[show abstract]
[hide abstract]
ABSTRACT: Cited References Count:23|SPRINGER-VERLAG|175 FIFTH AVE, NEW YORK, NY 10010 USA|Gadea, A|Napoli, DR|de Angelis, G|Menegazzo, R|Stefanini, AM|Corradi, L|Axiotis, M|Berti, L|Fioretto, E|Kroell, T|Latina, A|Marginean, N|Maron, G|Martinez, T|Rosso, D|Rusu, C|Toniolo, N|Szilner, S|Trotta, M|Bazzacco, D|Beghini, S|Bellato, M|Brandolini, F|Farnea, E|Isocrate, R|Lenzi, SM|Lunardi, S|Montagnoli, G|Pavan, P|Alvarez, CR|Scarlassara, F|Ur, C|Blasi, N|Bracco, A|Camera, F|Leoni, S|Million, B|Pignanelli, M|Pollarolo, G|DeRosa, A|Inglima, C|La Commara, M|La Rana, G|Pierroutsakou, D|Romoli, M|Sandoli, M|Bizzeti, PG|Bizzeti-Sona, AM|Lo Bianco, G|Petrache, CM|Zucchiatti, A|Cocconi, P|Quintana, B|Beck, C|Curien, D|Duchene, G|Haas, F|Medina, P|Papka, P|Durell, J|Freeman, SJ|Smith, A|Varley, B|Fayz, K|Pucknell, V|Simpson, J|Gelletly, W|Regan, P|EUROBALL PRISMA-2 Collaborat|ISI Document Delivery No.:820OV
20:193-197.
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L. Nelson,
M.R. Dimmock,
A.J. Boston,
H.C. Boston,
J.R. Cresswell,
P.J. Nolan,
I. Lazarus,
J. Simpson, P. Medina,
C. Santos,
C. Parisel
[show abstract]
[hide abstract]
ABSTRACT: The Advanced GAmma Tracking Array (AGATA) symmetric prototype detector has been tested at the University of Liverpool. A 137Ce source, collimated to a 2 mm diameter, was scanned across the front face of the detector and data were acquired utilising digital electronics. Pulse shapes from a selection of well-defined photon interaction positions have been analysed to investigate the position sensitivity of the detector. Furthermore, the application of the electric field simulation software, Multi Geometry Simulation (MGS) to generate theoretical pulse shapes for AGATA detectors has been presented.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
