Micromegas, a multipurpose gaseous detector Charpak, G; Derré, J; Giomataris, Y ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2002, Letnik:
478, Številka:
1
Journal Article
Recenzirano
In this paper the advantages of a new gaseous detector. Micromegas, are described. Some of its properties are given and the consequences are out-lined in a series of experiments related to charged ...particle localization, neutron imaging, gamma or X-ray imaging.
Fast signals and single electron detection with a MICROMEGAS photodetector Derré, J; Giomataris, Y; Rebourgeard, Ph ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2000, Letnik:
449, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The performance of a new gaseous photodetector was investigated. It consists of a solid photocathode and a gas amplification structure of the MICROMEGAS type. Using a mixture of helium and isobutane ...at atmospheric pressure, a stable and high amplification gain close to 10
7 was achieved. Such a high gain and small fluctuations allowed the detection of single photoelectrons with a time resolution better than 700 ps. These performances are comparable with those obtained with the best photomultipliers.
Spatial resolution in Micromegas detectors Derré, J.; Giomataris, Y.; Zaccone, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2001, Letnik:
459, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The performance of a telescope of Micromegas detectors has been studied in a pion beam at the CERN PS. With a gas filling of CF
4 and 20% isobutane and with a strip pitch of 100
μm an accuracy of ...14±3
μm on the spatial resolution has been measured at normal incidence. A simulation demonstrates that the resolution is limited by the size of the holes of the mesh of the detector and could be reduced to 11
μm in the same conditions with smaller holes. Even further improvement down to 8.5
μm is feasible for the same gas with an optimized 75
μm strip pitch.
The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003–2004. A new upper limit on the rate of the lepton number ...violating decay K±→π∓μ±μ± is reported: B(K±→π∓μ±μ±)<8.6×10−11 at 90% CL. Searches for two-body resonances X in K±→πμμ decays (such as heavy neutral leptons N4 and inflatons χ) are also presented. In the absence of signals, upper limits are set on the products of branching fractions B(K±→μ±N4)B(N4→πμ) and B(K±→π±X)B(X→μ+μ−) for ranges of assumed resonance masses and lifetimes. The limits are in the (10−11,10−9) range for resonance lifetimes below 100 ps.
Recent experimental results with MICROMEGAS Derré, J; Giomataris, I
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2002, Letnik:
477, Številka:
1
Journal Article
Recenzirano
We report on recent measurements with MICROMEGAS: spatial resolution, rate capability and photodetection.
The spatial resolution at CERN PS beam has been studied using several gas mixtures. With a ...gas filling of CF4 and 20% isobutane an accuracy of 14
μm has been measured at normal incidence.
An optimized gas mixture for operation at high rate environments and especially for the LHC has been found.
The study of a new gas photodetector with a CsI photocathode and a gas amplification structure of the MICROMEGAS type is presented. A high single electron efficiency and a time resolution of better than 700
ps was obtained.
Study of sparking in Micromegas chambers Bay, A; Perroud, J.-P; Ronga, F ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2002, Letnik:
488, Številka:
1
Journal Article
Recenzirano
The discharge properties of Micromegas detector are studied in detail. Tests have demonstrated that the origin of discharges in hadron beams is mainly associated with nuclear interactions of the ...incident particle with the gas of the detector. Use of low average Z gas mixtures diminishes the spark rate. The streamer discharge model of Raether has been proved to be valid for this detector. A detector polarization which minimizes the spark energy is proposed. Gas and geometry factors improving the discharge limit are discussed.
A technique for nonradioactive in situ hybridization on human metaphase chromosomes has been developed to localize human cosmid clones. The simple procedure using two fluorescent dyes (fluorescein ...and propidium iodide) allows the simultaneous identification of chromosomal R-bands and hybridization signal in a single screening of the slides. This technique has been used for rapid correlation of the genetic and physical map of chromosome 11q13-qter in the region of genes responsible for ataxia-telangiectasia and tuberous sclerosis.
Micromegas technology is a promising candidate to replace Atlas forward muon chambers -tracking and trigger- for future HL-LHC upgrade of the experiment. The increase on background and pile-up event ...probability requires detector performances which are currently under studies in intensive RD activities. We studied performances of four different resistive Micromegas detectors with different read-out strip pitches. These chambers were tested using ~120 GeV momentum pions, at H6 CERN-SPS beam line in autumn 2010. For a strip pitch 500μm we measure a resolution of ~90 μm and a efficiency of ~ 98%. The track angle effect on the efficiency was also studied. Our results show that resistive techniques induce no degradation on the efficiency or resolution, with respect to the standard Micromegas. In some configuration the resistive coating is able to reduce the discharge currents at least by a factor of 100.
A
bstract
The NA48/2 experiment at CERN reports the first observation of the
K
±
→
π
0
π
0
μ
±
ν
decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. ...The decay branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV
2
/
c
4
is measured to be (0.65 ± 0.03) × 10
−
6
. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10
−
6
, in agreement with chiral perturbation theory predictions.
Spatial resolution and rate capability of MICROMEGAS detector Derré, J.; Giomataris, I.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2001, Letnik:
461, Številka:
1
Journal Article
Recenzirano
We report on recent measurements of MICROMEGAS: spatial resolution and rate capability.The spatial resolution has been studied using several gas mixtures at the CERN PS test beam. With a gas filling ...of CF
4 and 20% isobutane, an accuracy of 12
μm has been measured at normal incidence. Optimized conditions and gas mixtures for operation at high-rate environments have been found.
PDF
