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[en] By taking part in a comparison measurement held at Hedi reservoir in Lianjiang City, Guangdong Province, the values of cosmic ray response factor were further verified for six RSS-131 high pressure ionization chambers in use in Guangdong Environmental Radiation Monitoring Center (GERC). The results show that the value range is 0.609-0.713, with an average of 0.651 and a standard deviation of 0.036. It indicates that the cosmic ray response factor is stable, and, with theoretical calculations combined, can be easily obtained for different regions, so as to solve the difficulties in cosmic ray measurement. (authors)
[en] The electric current of ex-core detector can be obtained from the scalar product of the spatial weighting function and the core power distribution. In this paper, the transportation calculation code DORT was used to evaluate spatial weighting function of the ex-core detector in two-dimensional geometry, and the cross sections were generated with the nuclear data library MATXS-47, which is processed from ENDF/B-Ⅶ.1. Applying the method to the Indian Point 2, the radial spatial weighting functions were calculated. The calculation results agree well with the reference values. (authors)
[en] One of the main design drivers for detectors at future energy-frontier colliders is the precise determination of the energy of particle jets. This is achieved with detector designs optimized for particle flow algorithms. CALICE is an R&D collaboration focussed on the development of highly granular calorimeters optimized to aid this paradigm by providing high spatial resolution. The Analogue Hadronic Calorimeter (AHCAL) is one of the detector concepts based on scintillating tiles read out by Silicon Photomultipliers. This calorimeter provides high spatial granularity and single-cell timing in order to enhance the particle separation and background rejection capability. A 22000 channel technological prototype has been constructed and extensively tested in particle beams at CERN in 2018. This contribution is focussed on the time analysis of the data taken in the course of these test beam campaigns. It will touch upon the correction of electronic effects caused by the read-out chip and report on the achievable hit time resolution.
[en] For the high luminosity phase of the LHC, the tracking system of the ATLAS experiment will be replaced with a new all-silicon detector called the Inner Tracker (ITk), to cope with the expected severe conditions in terms of radiation and occupancy. With the production of modules scheduled to begin in 2020, a thorough understanding of the current prototype modules is critical. Beam Tests allow, to some extent, to simulate real experimental conditions and test the module performance. This talk presents the results of beam tests at DESY and CERN. The devices under test are the first ever double-sided R0 module built from non-irradiated silicon sensors and a single R0 module irradiated up to a dose of 1.1 10 n/cm. The R0 module will occupy the innermost position in the end-cap wheels of the ITk-strip detector system and will face the highest radiation dose. The results presented focus on the detection efficiency and spatial resolution of the modules.
[en] Photomultiplier-Tubes are photodetectors with good single photon resolution. For the optimal photon reconstruction the PMT gain is required to 1E7 e- per electron. The gain of the PMT depends exponentially on the applied high voltage. By regulating the high voltage, the gain can be tuned and stabilized. By using the presented technique it is possible to simply connect all PMTs to the readout system, without characterizing the gain and the correct HV beforehand. By using the charge of dark counts there is no need for a special light source in the detector for implementing this procedure. Potential changes of the PMT gain can be compensated during runtime. This concept will be implemented and tested in the OSIRIS detector.
[en] During the current long shutdown of the LHC the LHCb detector will undergo a comprehensive upgrade. An important part of this upgrade is the replacement of the current downstream tracking stations by a detector made of scintillating fibres. These fibres are wound and glued to form mats with a length of 2.5 m. Charged particles crossing the scintillator emit light which is then guided by total internal reflection towards silicon photo multipliers at the end of the mat. The amount of light observed at the end of the fibre is an important predictor for the performance of the system. This so called light yield is among other things affected by irradiation damage of the fibres. Hence it is important to understand and quantify these effects in order to predict the performance of the tracker during its life time. In this talk several approaches to the simulation of scintillating fibres are presented. Special emphasis is put on the development of effective models from simulation studies and measurements of single fibres.
[en] Gaseous detectors are widely used in the field of particle physics research, such as at the main experiments of the LHC. Given the increasing demand of precision and reliability of the detectors for the discovery of new particles, it is essential to better understand the details of the already existing detectors and those of the next generation. To achieve this, the generation and propagation of signals inside the detectors are studied on a microscopic scale. Simulations are performed using the Garfield++ package mainly focusing on GEM detectors. Starting from ionizing particles, the ion-electron pairs are generated in the gas volume. The electrons are propagated towards the regions of high electric field where the electron multiplication takes place. Finally the collection of the signal on the electrodes is simulated. The studies presented here cover the influence of environmental parameters, detector geometry, high voltage distribution and gas composition.
[en] For the planned upgrade of the IceCube neutrino telescope, seven additional strings equipped with new optical modules will be installed in the center of DeepCore, the current low energy IceCube extension. The upgrade will significantly enhance IceCube's low-energy neutrino detection capabilities with the goal of performing precision measurements in atmospheric neutrino oscillation, and improve the calibration of the existing IceCube detector in particular also for the reconstruction of astrophysical high-energy neutrinos. In order to achieve these goals, a crucial pre-requisite is to accurately distinguish between neutrinos and atmospheric muons. This study presents initial studies on event selection algorithms and their performance.
[en] The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kt liquid scintillator reactor neutrino experiment currently being built in the Guangdong province in southern China. In order to reliably reconstruct neutrino-induced inverse beta decay events from photomultiplier signals, scintillator purity is imperative. Potential air leaks in the filling and cycling lines or failures of the purification plants are risks that endanger the high radiopurity necessary to obtain clean signals within such a large active target volume. The Online Scintillator Internal Radioactivity Investigation System (OSIRIS) is being developed as a failsafe monitor to assess the quality of the scintillator batches before filling them into the central detector. This presentation serves as a general introduction to the project concept, design and schedule, with more details on software and hardware shown in their own respective talks.
[en] The IceCube Neutrino Observatory is a km scale Cherenkov light detector that also searches for signatures of particles beyond the standard model. Sub-relativistic magnetic monopoles may catalyze proton decay via the Rubakov-Callan effect. Icecube can detect the Cherenkov light induced by this process. However, the cross-section for this process is model dependent and ranges over several orders of magnitude. This results in diverse signatures of monopoles, slowly moving through the detector. Thus, it is important to find significant variables that characterize the signal with respect to background. In this talk, we present a new selection method based on machine learning.