320 research outputs found
The effect of the displacement damage on the Charge Collection Efficiency in Silicon Drift Detectors for the LOFT satellite
The technology of Silicon Drift Detectors (SDDs) has been selected for the
two instruments aboard the Large Observatory For X-ray Timing (LOFT) space
mission. LOFT underwent a three year long assessment phase as candidate for the
M3 launch opportunity within the "Cosmic Vision 2015 -- 2025" long-term science
plan of the European Space Agency. During the LOFT assessment phase, we studied
the displacement damage produced in the SDDs by the protons trapped in the
Earth's magnetosphere. In a previous paper we discussed the effects of the Non
Ionising Energy Losses from protons on the SDD leakage current. In this paper
we report the measurement of the variation of Charge Collection Efficiency
produced by displacement damage caused by protons and the comparison with the
expected damage in orbit.Comment: 17 pages, 7 figures. Accepted for publication by Journal of
Instrumentatio
Thermal Grease Evaluation for ATLAS Upgrade Micro-Strip Detector.
The ATLAS upgrade detector foreseen at the phase 2 upgrade of LHC requires a complete new inner detector using silicon pixel and strip detectors. For both technologies, a specific mechanical and thermal design is required. Such a design may use soft thermal interfaces such as grease between the various parts. One foreseeable use would be between the cooling pipe and the thermal block allowing the strip modules to be decoupled from the mechanical and cooling structure. This note describes the technique used and the results obtained when characterizing a few grease samples. The results have been compared with thermal FEA simulations. A thermal conductivity measurement for each sample could be extracted from the measurements, with a systematic uncertainty of less than 6%. Some samples were irradiated to the expected fluence at sLHC and their resulting thermal conductivity compared with the non-irradiated samples
Modelling of simple cases in view of active stabilisation for a future linear collider
Final focus magnet stabilisation is an important issue when working with nanometre size beams. The present study focuses on mechanical stabilisation. As a first step, the case of a 1m free-fixed aluminium beam placed on a table with active stabilisation has been studied. This work describes three aspects, namely, sensors and actuators to measure and compensate ground motion, mechanical simulations and a feedback loop. Measurements done with low frequency velocity sensors (down to 0.1Hz) in our Annecy lab during office hours show that the displacement RMS on the active table is 1nm at 4Hz compared to 10nm without active stabilisation. Simulations of the dynamic response of the beam have been compared to measurements done with accelerometers placed on the clamping and on the free end of the aluminium beam. The results are in good agreement. We are therefore able to predict by simulation the response of a structure subjected to an external excitation. A first sketch of a feedback loop to compensate specific vibrations has also been developed and allows the simultaneous elimination of several resonance peaks on a reduced-size mock-up. This algorithm will be applied to stabilise a larger mock-up, leading to more realistic experimental conditions. In future tests, the active table will globally stabilise in a range of frequencies from 0.5Hz to 50Hz whereas the feedback loop will compensate single strong resonances
Penetrating particle ANalyzer (PAN)
PAN is a scientific instrument suitable for deep space and interplanetary
missions. It can precisely measure and monitor the flux, composition, and
direction of highly penetrating particles (100 MeV/nucleon) in deep
space, over at least one full solar cycle (~11 years). The science program of
PAN is multi- and cross-disciplinary, covering cosmic ray physics, solar
physics, space weather and space travel. PAN will fill an observation gap of
galactic cosmic rays in the GeV region, and provide precise information of the
spectrum, composition and emission time of energetic particle originated from
the Sun. The precise measurement and monitoring of the energetic particles is
also a unique contribution to space weather studies. PAN will map the flux and
composition of penetrating particles, which cannot be shielded effectively,
precisely and continuously, providing valuable input for the assessment of the
related health risk, and for the development of an adequate mitigation
strategy. PAN has the potential to become a standard on-board instrument for
deep space human travel.
PAN is based on the proven detection principle of a magnetic spectrometer,
but with novel layout and detection concept. It will adopt advanced particle
detection technologies and industrial processes optimized for deep space
application. The device will require limited mass (~20 kg) and power (~20 W)
budget. Dipole magnet sectors built from high field permanent magnet Halbach
arrays, instrumented in a modular fashion with high resolution silicon strip
detectors, allow to reach an energy resolution better than 10\% for nuclei from
H to Fe at 1 GeV/n
Proposal for SPS beam time for the baby MIND and TASD neutrino detector prototypes
The design, construction and testing of neutrino detector prototypes at CERN
are ongoing activities. This document reports on the design of solid state baby
MIND and TASD detector prototypes and outlines requirements for a test beam at
CERN to test these, tentatively planned on the H8 beamline in the North Area,
which is equipped with a large aperture magnet. The current proposal is
submitted to be considered in light of the recently approved projects related
to neutrino activities with the SPS in the North Area in the medium term
2015-2020
Internal alignment and position resolution of the silicon tracker of DAMPE determined with orbit data
The DArk Matter Particle Explorer (DAMPE) is a space-borne particle detector
designed to probe electrons and gamma-rays in the few GeV to 10 TeV energy
range, as well as cosmic-ray proton and nuclei components between 10 GeV and
100 TeV. The silicon-tungsten tracker-converter is a crucial component of
DAMPE. It allows the direction of incoming photons converting into
electron-positron pairs to be estimated, and the trajectory and charge (Z) of
cosmic-ray particles to be identified. It consists of 768 silicon micro-strip
sensors assembled in 6 double layers with a total active area of 6.6 m.
Silicon planes are interleaved with three layers of tungsten plates, resulting
in about one radiation length of material in the tracker. Internal alignment
parameters of the tracker have been determined on orbit, with non-showering
protons and helium nuclei. We describe the alignment procedure and present the
position resolution and alignment stability measurements
A PMT-Block test bench
The front-end electronics of the ATLAS hadronic calorimeter (Tile Cal) is
housed in a unit, called {\it PMT-Block}. The PMT-Block is a compact instrument
comprising a light mixer, a PMT together with its divider and a {\it 3-in-1}
card, which provides shaping, amplification and integration for the signals.
This instrument needs to be qualified before being assembled on the detector. A
PMT-Block test bench has been developed for this purpose. This test bench is a
system which allows fast, albeit accurate enough, measurements of the main
properties of a complete PMT-Block. The system, both hardware and software, and
the protocol used for the PMT-Blocks characterisation are described in detail
in this report. The results obtained in the test of about 10000 PMT-Blocks
needed for the instrumentation of the ATLAS (LHC-CERN) hadronic Tile
Calorimeter are also reported.Comment: 23 pages, 10 figure
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