One of the major drawbacks of a SiPM is due to the so-called cross-talk effect. Often, one single photon in a chain reaction can generate more photons and thus can fire more than one micro-cell of a ...SiPM. This can be considered as a noise in the signal multiplication process and this degrades the signal/noise ratio. In self-trigger schemes this noise can be so high that it can make operating them difficult at low threshold settings. For the past few years, we have dwelt on this effect aiming to suppress it at the design stage. One can use (a) trenches around the micro-cells for suppressing the direct photon “communication” channel and (b) the so-called double p–n junction for suppressing photon-induced charge “communication” in neighbor pixels. The low cross-talk is mandatory, for example, for producing SiPM-based light sensor modules for the Imaging Atmospheric Cherenkov Technique projects for ground-based gamma-ray astrophysics. We produced and tested a few modules consisting of 4 SiPMs, each with a size of 5
mm×5
mm of custom production type. We report here on the main parameters of these units.
The operation of gas proportional chambers in the transition radiation detectors (TRD) in the experiments in the future high-luminosity colliders will be limited due to an extremely high particle ...intensity. Therefore, the development of TRD on the basis of thin inorganic high Z scintillator films is interesting. The results of beam studies of TRD based on thin CsI (Na) film are discussed.
The exclusive photoproduction reaction γp→ϒp has been studied with the ZEUS experiment in ep collisions at HERA using an integrated luminosity of 468 pb−1. The measurement covers the kinematic range ...60<W<220 GeV and Q2<1 GeV2, where W is the photon–proton centre-of-mass energy and Q2 is the photon virtuality. These results, which represent the analysis of the full ZEUS data sample for this channel, are compared to predictions based on perturbative QCD.
Large area UV SiPMs with extremely low cross-talk Dolgoshein, B.; Mirzoyan, R.; Popova, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2012, Letnik:
695
Journal Article
Recenzirano
For about ten years the collaboration MEPhI-Max Plank Institute for Physics in Munich has been developing SiPMs for the MAGIC and EUSO astro-particle physics experiments. The aim was to develop UV ...sensitive sensors of very high photon detection efficiency, substantially exceeding that of the classical photo multiplier tubes. For very high photo detection efficiency one needs to operate SiPM under the highest Geiger efficiency, i.e., to apply a high over-voltage. This means operating SiPM under high gain that in its turn produces a very high cross-talk. For suppressing the latter adverse effect we used isolating trenches and a second p–n junction, but also special implantation profiles and layers. We produced UV sensitive SiPMs of sizes 1mm×1mm and 3mm×3mm showing a peak Photon Detection Efficiency in the range of 50–60% at a cross-talk level of only 3–5%. One of the outstanding features of the new SiPM is their extremely low sensitivity of gain to temperature variations, amounting to 0.5%/°C. Below we report on new SiPMs.
Large area silicon photomultipliers: Performance and applications Buzhan, P.; Dolgoshein, B.; Filatov, L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2006, Letnik:
567, Številka:
1
Journal Article
Recenzirano
The Silicon Photomultipliers (SiPMs) with large area up to
10
×
10
mm
2
are considered and their optimal parameters, such as efficiency, gain, dark rate, afterpulsing probability and optical ...crosstalk are discussed. The
3
×
3
mm
2
SiPM is described and its performance is demonstrated. Three examples of
3
×
3
mm
2
SiPM application are given: (1) transition radiation X-ray detection; (2) time of flight measurements with fast scintillators; (3) detection of PET gammas using LYSO crystals. Corresponding experimental results are presented and discussed.
Inclusive-jet cross sections have been measured in the reaction ep→e+jet+X for photon virtuality Q2<1 GeV2 and γp centre-of-mass energies in the region 142<Wγp<293 GeV with the ZEUS detector at HERA ...using an integrated luminosity of 300 pb−1. Jets were identified using the kT, anti-kT or SIScone jet algorithms in the laboratory frame. Single-differential cross sections are presented as functions of the jet transverse energy, ETjet, and pseudorapidity, ηjet, for jets with ETjet>17 GeV and −1<ηjet<2.5. In addition, measurements of double-differential inclusive-jet cross sections are presented as functions of ETjet in different regions of ηjet. Next-to-leading-order QCD calculations give a good description of the measurements, except for jets with low ETjet and high ηjet. The influence of non-perturbative effects not related to hadronisation was studied. Measurements of the ratios of cross sections using different jet algorithms are also presented; the measured ratios are well described by calculations including up to O(αs2) terms. Values of αs(MZ) were extracted from the measurements and the energy-scale dependence of the coupling was determined. The value of αs(MZ) extracted from the measurements based on the kT jet algorithm is αs(MZ)=0.1206−0.0022+0.0023(exp.)−0.0035+0.0042(th.); the results from the anti-kT and SIScone algorithms are compatible with this value and have a similar precision.
The GAMMA-400 telescope is designed to investigate discrete high-energy gamma-ray sources in the energy range of 0.1–3000 GeV, to measure the energy spectra of galactic and extragalactic diffuse ...gammaray emissions, and to study gamma-ray bursts and gamma-ray emissions from an active Sun. The gamma-ray telescope has an angular resolution of ∼0.01°, an energy resolution of ∼1%, and a proton rejection factor of ∼10
6
. Its special assignment is to measure fluxes of gamma rays, electrons, and positrons that could be associated with the annihilation or decay of dark matter particles.
The ATLAS Inner Detector consists of three sub-systems, the Pixel Detector at the innermost radius, the Semi-Conductor Tracker at intermediate radii, and the Transition Radiation Tracker (TRT) at the ...outermost radius in front of the electromagnetic calorimeter. The TRT provides a combination of continuous tracking with many projective measurements based on individual drift-tubes (or straws) and of electron identification based on radiator fibres or foils interleaved between the straws themselves. This paper describes the current status of design and construction of the various components of the TRT: the assembly of the barrel modules has recently been completed, that of the end-cap wheels is well underway, and the on-detector front-end electronics is in production. The detector modules and front-end electronics boards will be integrated together over the next year, the barrel and end-cap TRT parts will be assembled and tested with their SCT counterparts during 2005 and installation and commissioning in the ATLAS pit will take place at the end of 2005 and the beginning of 2006.
The GAMMA-400 space observatory will provide precise measurements of gamma rays, electrons, and positrons in the energy range 0.1-3000 GeV. The good angular and energy resolutions, as well as ...identification capabilities (angular resolution ~0.01°, energy resolution ~1%, and proton rejection factor ~10 6 ) will allow us to study the main galactic and extragalactic sources, diffuse gamma-ray background, gamma-ray bursts, and to measure electron and positron fluxes. The peculiar characteristics of the experiment is simultaneous detection of gamma rays and cosmic-ray electrons and positrons, which can be connected with annihilation or decay of dark matter particles.
Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 320 pb−1. Measurements were made in the isolated-photon ...transverse-energy and pseudorapidity ranges 4<ETγ<15 GeV and −0.7<ηγ<0.9 for exchanged photon virtualities, Q2, in the range 10<Q2<350 GeV2 and for invariant masses of the hadronic system WX>5 GeV. Differential cross sections are presented for inclusive isolated photon production as functions of Q2, x, ETγ and ηγ. Leading-logarithm parton-shower Monte Carlo simulations and perturbative QCD predictions give a reasonable description of the data over most of the kinematic range.
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