5,043 research outputs found
Mass and Isospin Effects in Multifragmentation
A systematic study of isospin effects in the breakup of projectile spectators
at relativistic energies has been performed with the ALADiN spectrometer at the
GSI laboratory (Darmstadt). Four different projectiles 197Au, 124La, 124Sn and
107Sn, all with an incident energy of 600 AMeV, have been used, thus allowing a
study of various combinations of masses and N/Z ratios in the entrance channel.
The measurement of the momentum vector and of the charge of all projectile
fragments with Z>1 entering the acceptance of the ALADiN magnet has been
performed with the high efficiency and resolution achieved with the TP-MUSIC IV
detector. The Rise and Fall behavior of the mean multiplicity of IMFs as a
function of Zbound and its dependence on the isotopic composition has been
determined for the studied systems. Other observables investigated so far
include mean N/Z values of the emitted light fragments and neutron
multiplicities. Qualitative agreement has been obtained between the observed
gross properties and the predictions of the Statistical Multifragmentation
Model.Comment: 10 pages,7 figure, 18th Nuclear Physics Division Conference of the
EPS, Prague, submitted to Nucl. Phys.
Trigger and readout electronics for the STEREO experiment
The STEREO experiment will search for a sterile neutrino by measuring the
anti-neutrino energy spectrum as a function of the distance from the source,
the ILL nuclear reactor. A dedicated electronic system, hosted in a single
microTCA crate, was designed for this experiment. It performs triggering in two
stages with various selectable conditions, processing and readout via UDP/IPBUS
of 68 photomultiplier signals continuously digitized at 250 MSPS. Additionally,
for detector performance monitoring, the electronics allow on-line calibration
by driving LED synchronously with the data acquisition. This paper describes
the electronics requirements, architecture and the performances achieved.Comment: Topical Workshop on Electronics for Particle Physics (TWEPP) 2015,
Lisboa. 9 pages, 9 figure
Improved 3D-imaging detection at the Cryogenic Storage Ring
The study of electron induced molecular fragmentation processes in fast-beam experiments sets high demands on the technical realization of appropriate detection techniques. A complete reconstruction of the total kinetic energy release and thus detailed physical information of this process can only be deduced from the fully correlated measurement of distances. Therefore, the reaction product detector must be able to measure both the impact positions on the detectors surface as well as the time difference between impacts with the highest resolution. In this work a new timing readout for the 3D-imaging detector NICE at the Cryogenic Storage Ring in Heidelberg was set up and tested for the first time. The upgrade is based on the silicon photomultiplier technology, employing a multi-pixel detector with high intrinsic time resolution. First performance test show promising results: it was possible to resolve spatially well separated impacts with a time difference down to zero, exceeding the time resolution limit of the pre-existing setup
Real-time digital signal processor implementation of self-calibrating pulse-shape discriminator for high purity germanium
Pulse-shape analysis of the ionization signals from germanium gamma-ray
spectrometers is a method for obtaining information that can characterize an
event beyond just the total energy deposited in the crystal. However, as
typically employed, this method is data-intensive requiring the digitization,
transfer, and recording of electronic signals from the spectrometer. A hardware
realization of a real-time digital signal processor for implementing a
parametric pulse shape is presented. Specifically, a previously developed
method for distinguishing between single-site and multi-site gamma-ray
interactions is demonstrated in an on-line digital signal processor, compared
with the original off-line pulse-shape analysis routine, and shown to have no
significant difference. Reduction of the amount of the recorded information per
event is shown to translate into higher duty-cycle data acquisition rates while
retaining the benefits of additional event characterization from pulse-shape
analysis.Comment: Accepted by NIM
A Large-Scale FPGA-Based Trigger and Dead-Time Free DAQ System for the Kaos Spectrometer at MAMI
The Kaos spectrometer is maintained by the A1 collaboration at the Mainz
Microtron MAMI with a focus on the study of (e,e'K^+) coincidence reactions.
For its electron-arm two vertical planes of fiber arrays, each comprising
approximately 10 000 fibers, are operated close to zero degree scattering angle
and in close proximity to the electron beam. A nearly dead-time free DAQ system
to acquire timing and tracking information has been installed for this
spectrometer arm. The signals of 144 multi-anode photomultipliers are collected
by 96-channel front-end boards, digitized by double-threshold discriminators
and the signal time is picked up by state-of-the-art F1 time-to-digital
converter chips. In order to minimize background rates a sophisticated trigger
logic was implemented in newly developed Vuprom modules. The trigger performs
noise suppression, signal cluster finding, particle tracking, and coincidence
timing, and can be expanded for kinematical matching (e'K^+) coincidences. The
full system was designed to process more than 4 000 read-out channels and to
cope with the high electron flux in the spectrometer and the high count rate
requirement of the detectors. It was successfully in-beam tested at MAMI in
2009.Comment: Contributed to 17th IEEE Real Time Conference (RT10), Lisbon, 24-28
May 201
A mobile antineutrino detector with plastic scintillators
We propose a new type segmented antineutrino detector made of plastic
scintillators for the nuclear safeguard application. A small prototype was
built and tested to measure background events. A satisfactory unmanned field
operation of the detector system was demonstrated. Besides, a detailed Monte
Carlo simulation code was developed to estimate the antineutrino detection
efficiency of the detector.Comment: 23 pages, 11 figures; accepted for publication in Nuclear Instruments
and Methods in Physics Research
GET: A generic electronics system for TPCs and nuclear physics instrumentation
General Electronics for TPCs (GET) is a generic, reconfigurable and comprehensive electronics and data-acquisition system for nuclear physics instrumentation of up to 33792 channels. The system consists of a custom-designed ASIC for signal processing, front-end cards that each house 4 ASIC chips and digitize the data in parallel through 12-bit ADCs, concentration boards to read and process the digital data from up to 16 ASICs, a 3-level trigger and master clock module to trigger the system and synchronize the data, as well as all of the associated firmware, communication and data-acquisition software. An overview of the system including its specifications and measured performances are presented
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