51,658 research outputs found
MIMAC : a micro-TPC detector for non-baryonic dark matter search
The MIMAC project is multi-chamber detector for Dark Matter search, aiming at
measuring both track and ionization with a matrix of micromegas micro-TPC
filled with He3 and CF4. Recent experimental results on the first measurements
of the Helium quenching factor at low energy (1 keV recoil) are presented.Comment: 7 pages, Proc of Dark Energy and Dark Matter conference, Lyon :
France (2008
A high dynamic Micro Strips Ionization Chamber featuring Embedded Multi DSP Processing
An X-ray detector will be presented that is the combination of a segmented
ionization chamber featuring one-dimensional spatial resolution integrated with
an intelligent ADC front-end, multi DSP processing and embedded PC platform.
This detector is optimized to fan beam geometry with an active area of 192 mm
(horizontal) and a vertical acceptance of 6 mm. Spatial resolution is obtained
by subdividing the anode into readout strips, having pitch of 150 micrometers,
which are connected to 20 custom made integrating VLSI chips (each capable of
64-channel read-out and multiplexing) and read out by 14 bits 10 MHz ADCs and
fast adaptive PGAs into DSP boards. A bandwidth reaching 3.2Gbit/s of raw data,
generated from the real time sampling of the 1280 micro strips, is cascaded
processed with FPGA and DSP to allow data compression resulting in several days
of uninterrupted acquisition capability. Fast acquisition rates reaching 10 kHz
are allowed due to the MicroCAT structure utilized not only as a shielding grid
in ionization chamber mode but also to provide active electron amplification in
the gas.Comment: 5 pages, 7 figures, distilled by AFPL Ghostscript 7.0
Development and test of the high-precision gamma-beam monitor at the ESFRI facility ELI-NP
This document describes the development of a fission chamber for gamma beam intensity monitoring at the high-energy gamma line at ELI-NP.
The fission chamber foreseen for monitoring the gamma beam intensity on the high-energy beam line at ELI-NP is an ionization chamber with several 238U deposits of a thickness in the range from 100 to 150 μg/cm2 in a compact design. The innovative design of the chamber allows measuring for each individual micro pulse arriving at a time interval of 1.6x10^-8 s.JRC.G.2-Standards for Nuclear Safety, Security and Safeguard
Neutral particle Mass Spectrometry with Nanomechanical Systems
Current approaches to Mass Spectrometry (MS) require ionization of the
analytes of interest. For high-mass species, the resulting charge state
distribution can be complex and difficult to interpret correctly. In this
article, using a setup comprising both conventional time-of-flight MS (TOF-MS)
and Nano-Electro-Mechanical-Systems-based MS (NEMS-MS) in situ, we show
directly that NEMS-MS analysis is insensitive to charge state: the spectrum
consists of a single peak whatever the species charge state, making it
significantly clearer than existing MS analysis. In subsequent tests, all
charged particles are electrostatically removed from the beam, and unlike
TOF-MS, NEMS-MS can still measure masses. This demonstrates the possibility to
measure mass spectra for neutral particles. Thus, it is possible to envisage
MS-based studies of analytes that are incompatible with current ionization
techniques and the way is now open for the development of cutting edge system
architectures with unique analytical capability
Medium-Energy Gamma-Ray Astrophysics with the 3-DTI Gamma-Ray Telescope
Gamma-ray observations in the medium energy range (0.50-50.0 MeV) are central to unfolding many outstanding questions in astrophysics. The challenges of medium-energy gamma-ray observations, however, are the low photon statistics and large backgrounds. We review these questions, address the telescope technology requirements, and describe our development of the 3-Dimensional Track Imaging (3-DTI) Compton telescope and its performance for a new mediumenergy gamma-ray mission. The 3-DTI is a large-volume time projection chamber (TPC) with a 2-dimensional gas micro-well detector (MWD) readout
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