The response of silicon–silicon–CsI(Tl) and silicon–CsI(Tl) telescopes to fragments produced in nuclear interactions has been studied. The telescopes were developed within the FAZIA collaboration. ...The capabilities of two methods are compared: (a) the standard
Δ
E
–
E
technique and (b) the digital Pulse Shape Analysis technique (for identification of nuclear fragments stopped in a single Si-layer). In a test setup, nuclear fragments covering a large range in nuclear charge, mass and energy were detected. They were produced in nuclear reactions induced by a 35A MeV beam of
129Xe impinging on various targets. It was found that the
Δ
E
–
E
correlations allow the identification of all isotopes up to
Z
∼
25
. With the digital Pulse Shape Analysis it is possible to fully distinguish the charge of stopped nuclei up to the maximum available
Z (slightly over that of the beam,
Z=54).
In the last few years the FAZIA
1 collaboration has been investigating the properties of silicon detectors – in particular the crystal orientation and resistivity non-uniformity – in order to better ...pin down the detector characteristics that influence their performances for particle identification using
Δ
E
−
E
and Pulse Shape Analysis (PSA) techniques. In this paper we present the first particle identification results obtained with detectors selected for good resistivity uniformity and using a “non-channeled” configuration. A new digital electronics was also designed for the R&D phase of FAZIA and was tested under beam for the first time. A quantitative procedure to measure the observed performances is applied in order to quantify the particle identification thresholds. Particle identification thresholds of
∼
2.5
AMeV
for
Z
∼
3
–
10
have been reached with the studied reaction.
FAZIA front-end electronics Salomon, F.; Edelbruck, P.; Brulin, G. ...
EPJ Web of Conferences,
01/2015, Letnik:
88
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
FAZIA is a multi-detector specifically designed to optimize ion identification in heavy-ion experiments. Its electronic is fully digital; it was designed in the laboratories of the collaboration. ...This paper presents the front-end part of this electronic.
FAZIA is a multidetector specifically designed to optimize A and Z reaction product identification in heavy-ion collision experiments. This multidetector is modular and based on three-layer ...telescopes made of two silicon detectors followed by a thick (10 cm) CsI(Tl) scintillator read-out by a photodiode. Its electronics is fully digital. The goal to push at maximum identification capability while preserving excellent energy resolution, can be achieved by using pulse-shape analysis techniques and by making an intensive use of high-speed flash ADCs. This paper presents the front-end part of the electronics.
New charge- and current-sensitive preamplifiers coupled to silicon detectors and devoted to studies in nuclear structure and dynamics have been developed and tested. For the first time shapes of ...current pulses from light charged particles and carbon ions are presented. Capabilities for pulse shape discrimination techniques are demonstrated.
Current pulses induced in a silicon detector by 10 different heavy ion species at known energies around 10
A
MeV have been sampled in time at high frequency. Their individual average shapes are quite ...well reproduced by a fit procedure based on our recent charge carrier collection treatment which considers the progressive extraction of the electrons and holes from the high carrier density zone along the ionizing particle track. This region is assumed to present a supplementary dielectric polarization and consequently a disturbed electric field. The influence of the nature of the heavy ion on the values of the three fit parameters is analyzed.
FAZIA is designed for detailed studies of the isospin degree of freedom, extending to the limits the isotopic identification of charged products from nuclear collisions when using silicon detectors ...and CsI(Tl) scintillators. We show that the FAZIA telescopes give isotopic identification up to Z~25 with a ΔE-E technique. Digital Pulse Shape Analysis makes possible elemental identification up to Z=55 and isotopic identification for Z=1-10 when using the response of a single silicon detector. The project is now in the phase of building a demonstrator comprising about 200 telescopes.
A study of the identification properties and of the energy response of a Si-Si-CsI(Tl) ΔE-E telescope exploiting a partially depleted second Si stage has been performed. Five different bias voltages ...have been applied to the second stage of the telescope, one corresponding to full depletion, the others associated with a depleted layer ranging from 60% to 90% of the detector thickness. Fragment identification has been obtained using either the ΔE-E technique or the Pulse Shape Analysis (PSA). Charge collection efficiency has been evaluated. The ΔE-E performance is not affected by incomplete depletion. Isotopic separation capability improves at lower bias voltages with respect to full depletion, though charge identification thresholds increase.
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.
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