3,010 research outputs found
Impact of dead zones on the response of a hadron calorimeter with projective and non-projective geometry
The aim of this study is to find an optimal mechanical design of the hadronic
calorimeter for SiD detector which takes into account engineering as well as
physics requirements. The study focuses on the crack effects between two
modules for various barrel mechanical design on calorimeter response. The
impact of different size of the supporting stringers and dead areas in an
active calorimeter layer along the module boundary has been studied for single
pions and muons. The emphasis has been put on the comparison of the projective
and non-projective barrel geometry for SiD hadronic calorimeter.Comment: 12 pages, 8 figure
Status of the Micromegas semi-DHCAL
The activities towards the fabrication and test of a 1 m3 semi-digital
hadronic calorime- ter are reviewed. The prototype sampling planes would
consist of 1 m2 Micromegas chambers with 1 cm2 granularity and embedded 2 bits
readout suitable for PFA calorime- try at an ILC detector. The design of the 1
m2 chamber is presented first, followed by an overview of the basic performance
of small prototypes. The basic units composing the 1 m2 chamber are 32 \times
48 cm2 boards with integrated electronics and a micro-mesh. Results of
character- ization tests of such boards are shown. Micromegas as a proportional
detector is well suited for semi-digital hadronic calorimetry. In order to
quantify the gain in perfor- mance when using one or more thresholds,
simulation studies are being carried out, some of which will be reported in
this contribution
Proposal of a new Hcal geometry avoiding cracks in the calorimeter
The classical geometry of a calorimeter consists most of the time in several modules, whose edges are pointing on the beam axis. Thus, detection discontinuities between two consecutive modules induce cracks in the calorimeter, and consequently a loss of precious information. This paper describes two new possible Hcal geometries avoiding such cracks in the detection. Then it deals with the internal layout and assembly procedure
Test in a beam of large-area Micromegas chambers for sampling calorimetry
Application of Micromegas for sampling calorimetry puts specific constraints
on the design and performance of this gaseous detector. In particular, uniform
and linear response, low noise and stability against high ionisation density
deposits are prerequisites to achieving good energy resolution. A
Micromegas-based hadronic calorimeter was proposed for an application at a
future linear collider experiment and three technologically advanced prototypes
of 11 m were constructed. Their merits relative to the
above-mentioned criteria are discussed on the basis of measurements performed
at the CERN SPS test-beam facility
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
Work Plans of the EUROTeV Technical Work Packages for 2005-2007
This report summarises the status of the work in the seven scientific Work Packages of EUROTeV as presented during the ILC-European Regional Meeting at Royal Holloway in June 2005. The purpose of the meeting was to monitor the progress and to contrast the developments inside EUROTeV with the worldwide developments of the GDE. The presentations of the entire meeting are available from http://www.pp.rhul.ac.uk/workshop/
Resistive micromegas for sampling calorimetry
MicromegasInternational audienceMicromegas is an attractive option for a gaseous sampling calorimeter. It delivers proportional and fast signals, achieves high efficiency to minimum ionising particles with a compact design and shows well-uniform performance over meter-square areas. The current R&D focuses on large- size spark-protected Micromegas with integrated front-end electronics. It targets an application at future linear colliders (LC) and possible upgrades of LHC experiments for the running at high luminosity. In the later case, occasional sparking should be suppressed to avoid dead-time and technical solutions using resistive coatings are investigated. Small prototypes of resistive and non-resistive Micromegas were constructed and tested in a beam at DESY. Results are reported with emphasis on the impact of the resistive layer on the detector performance
MICROMEGAS chambers for hadronic calorimetry at a future linear collider
Prototypes of MICROMEGAS chambers, using bulk technology and analog readout,
with 1x1cm2 readout segmentation have been built and tested. Measurements in
Ar/iC4H10 (95/5) and Ar/CO2 (80/20) are reported. The dependency of the
prototypes gas gain versus pressure, gas temperature and amplification gap
thickness variations has been measured with an 55Fe source and a method for
temperature and pressure correction of data is presented. A stack of four
chambers has been tested in 200GeV/c and 7GeV/c muon and pion beams
respectively. Measurements of response uniformity, detection efficiency and hit
multiplicity are reported. A bulk MICROMEGAS prototype with embedded digital
readout electronics has been assembled and tested. The chamber layout and first
results are presented
Large Area Micromegas Chambers with Embedded Front-end Electronics for Hadron Calorimetry
AbstractMicromegas (Micro-mesh gaseous structure) is an attractive technology for applications in particle physics experiments (TPC, calorimeters, muon systems, etc.). The most important results of an extensive R&D program aiming to develop a new generation of a fine-grained hadron calorimeter with low power consumption digital readout using Micromegas chambers as an active element are presented. In 2010, the first large scale prototype of Micromegas chamber with almost 8000 readout channels has been built and tested with high energy particle beams at CERN. The fundamental results, such as detection effciency, hit multiplicity, gain stability, response uniformity and effect of power pulsing of the detector front-end electronics are reported. Eventually, the development and test of the second generation of the large scale prototype with new readout electronics and some important improvements of its mechanical design is described and the prospective towards the construction of a technological prototype of a 4.5 λ deep digital calorimeter for a future linear collider is also given
Recent results of Micromegas sDHCAL with a new readout chip
Calorimetry at future linear colliders could be based on a particle flow
approach where granularity is the key to high jet energy resolution. Among
different technologies, Micromegas chambers with 1 cm2 pad segmentation are
studied for the active medium of a hadronic calorimeter. A chamber of 1 m2 with
9216 channels read out by a low noise front-end ASIC called MICROROC has
recently been constructed and tested. Chamber design, ASIC circuitry and
preliminary test beam results are reported
- …