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• A prototype system is developed to profile outcomes of 50 filtering acceptance levels (FAL). • Experiments on 27 unsupervised and 29 supervised granulated datasets are conducted. • An algorithm is developed to separate noise labels using 50 FALS. • Experimental results using five classification-oriented classifiers are presented. • Effects of 50 FALs on classification performance are profiled and summarized. Deciding whether a label in a dataset is noisy or not depends on factors such as filtering levels, data patterns, relabeling policies, and pre-defined regulations. By focusing on filtering acceptance levels (FAL), a decision support model (named DSM-ENL) is proposed and implemented on real datasets that are granulated, dealing with noise label detection and profiling effects of 50 FALs (51 %–100 %) on noise rate (NoR), classification accuracy (CA), and area under ROC curve (AUC). A case used to demonstrate the DSM-ENL is illustrated, followed by experiments on 27 unsupervised and 29 supervised granulated datasets using five classifiers with 70 %–30 % training and testing criteria. The findings revealed that: (1) the best CAs among classifiers vary with FALs; (2) NoR, CA, and AUC oscillate as FAL increases; (3) lower FAL boundaries (from 0.51 to 0.60) are more likely to lead to higher CAs; and (4) correlation of coefficient among dataset characteristics, FAL, NoR, CA, and AUC are not high compared to that of CA and NoR and that of CA and AUC. The research demonstrates the value of profiling the effects of FALs applied for noise-label datasets on learning performance. [ABSTRACT FROM AUTHOR]

Abstract Results of radiation tests of Hamamatsu 2.0 × 2.0 mm 2 through-silicon-via (S13360-2050VE) multi-pixel photon counters, or MPPCs, are presented (Hamamatsu, 0000). Distinct sets of eight MPPCs were exposed to four different 1 MeV neutron equivalent doses of 200 MeV protons. Measurements of the breakdown voltage, gain and noise rates at different bias overvoltages, photoelectron thresholds, and LED illumination levels were taken before and after irradiation. No significant deterioration in performance was observed for breakdown voltage, gain, and response. Noise rates increased significantly with irradiation. These studies were undertaken in the context of MPPC requirements for the Cosmic Ray Veto detector of the Mu2e experiment at the Fermi National Accelerator Laboratory. [ABSTRACT FROM AUTHOR]

The Compressed Baryonic Matter (CBM) experiment is one of the major scientific spectrometers of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. As one of the core sub-systems in CBM experiment for charged hadron identification, the Time-of-Flight (TOF) system is required to have a time resolution better than 80 ps. According to the final state particle flux distribution, the CBM-TOF will be constructed with several types of Multi-gap Resistive Plate Chambers (MRPC). In the outer region of the TOF wall where the particle fluxes are around 1 kHz/cm2, MRPCs with ultra-thin float glass electrodes are considered as a cost effective solution. MRPC3b prototypes have been developed and tested with excellent performance which could meet all the requirements. Before the construction of CBM-TOF, approximately 80 MRPC3bs are assembled for the STAR endcap TOF (STAR-eTOF) upgrade at RHIC as part of the FAIR Phase-0 programs for CBM-TOF which provides a valuable opportunity for detector stability test under high flux environments. This paper will introduce the batch test of the MRPC3bs for STAR-eTOF upgrade. Time resolution of better than 70 ps and efficiency of around 95% are achieved. Notably, during the batch test, it has been observed that the noise rates of the two edge strips in each counter are significantly higher than those of the middle strips. Simulations with Computer Simulation Technology (CST) Studio Suite are carried out and several kinds of MRPC prototypes are designed and tested accordingly. Based on the simulation and test results, the design of the MRPC3b has been further optimized by modify the shape and position of High-Voltage injection pad and increasing the distance between the glass edge and both end strips, resulting in a significant suppression of noise rates in the edge strips. [ABSTRACT FROM AUTHOR]

There are several working groups that are currently working on high rate RPC's using different materials such as Si-based ceramics, low-resistivity glass, low-resistive bakelite etc. A new type of single gap RPC has been fabricated using very low-resistive carbon-loaded PTFE material to compete with all these other groups and materials. In terms of bulk resistivity, this material show a very low bulk resistivity and should in principle be able to work at the highest rates, provided the material can withstand working bias and radiation. The efficiency and noise rate of the RPC are measured with cosmic rays. The detailed method of fabrication and first experimental results are presented. [ABSTRACT FROM AUTHOR]

Resistive Plate Chamber is a well-known gaseous detector in the field of High Energy Physics experiments for its good tracking capability, high efficiency, good time resolution, and low cost of fabrication. The main issue in Resistive Plate Chamber is its limitation in the rate handling capability. Several experimental groups have developed sophisticated techniques to increase the particle rate capability and reduce the noise rate of this detector. In bakelite Resistive Plate Chamber linseed oil coating on the inner electrode surface is done to get rid of surface roughness of the resistive electrodes. We developed a new method for linseed oil coating in case of bakelite Resistive Plate Chamber to achieve good efficiency (> 90%). In this article, we discussed the test results obtained from a prototype fabricated in this new method, using a conventional gas mixture. [ABSTRACT FROM AUTHOR]

Single gap Resistive Plate Chamber (RPC) is one of the very popular gaseous detectors used in high-energy physics experiments nowadays. It is a very fast detector having low cost of fabrication. The RPCs are usually built using glass or bakelite plates having high resistivity ∼ 1 0 10 – 1 0 11 Ω cm. Bakelite RPCs are generally fabricated with a linseed oil coating inside to make the inner electrode surface smoother which helps to reduce the micro discharge probability. Linseed oil coating also reduces the surface UV sensitivity dramatically and effectively protect the bakelite surfaces from the Hydrofluoric Acid (HF), produced by the interaction of fluorine with the water vapour. There is a conventional way to do this linseed oil coating after making the gas gap as done in experiments e. g. ALICE, CMS etc. A new technique is introduced here to do the linseed oil coating on the bakelite plate before making the gas gap. 100% Tetrafluoroethane (C 2 H 2 F 4) gas is used to test the RPC module in the avalanche mode with cosmic rays. Conventional NIM electronics is used for this study. The efficiency and noise rate are measured. In this article, the detailed method of fabrication and the first test results are presented. [ABSTRACT FROM AUTHOR]

The first CMS MB2 station, with one RPC and one DT module, has been tested with a muon beam under a high intensity photon flux at the CERN Gamma Irradiation Facility during the Autumn 2001 test. Results on efficiency, rate capability, cluster size and spatial resolution, for the RPC detector, are reported here. Studies with a small percentage of SF6 in the gas mixture, in order to decrease the noise rate, have also been carried out. [Copyright &y& Elsevier]

Abstract: Pixelated photon detectors (PPDs) are arrayed APDs operated in Geiger-mode. Multi-pixel photon counter (MPPC) is a PPD produced by Hamamatsu Photonics K.K. We performed measurement of total noise rate, random noise rate, after-pulsing, crosstalk, and relative photon detection efficiency for a 1600px MPPC. The explosive increase of total noise rate to over-voltage is able to be understood of multiplication effect of after-pulsing and crosstalk. Considering the electric field structure of MPPC (p-on-n type) and Geiger-efficiency as a function of the position of initial pair creation, these characteristics are all able to be understood. One suggestion for p-on-n type PPD from these results is narrowing the depletion layer below the multiplication layer to reduce random noise and after-pulsing. Another proposal is to put additional buffer capacitance parallel to the diode to accomplish higher gain with lower over-voltage simultaneously with lower noise rate. [ABSTRACT FROM AUTHOR]