A detector with high detection efficiency in 4- and 5-photon-positronium annihilations

2002 ◽  
Vol 80 (11) ◽  
pp. 1287-1295
Author(s):  
M Chiba ◽  
J Nakagawa ◽  
H Tsugawa ◽  
R Ogata ◽  
T Nishimura
Keyword(s):  
Standard Deviation ◽  
Quantum Electrodynamic ◽  
Detection Efficiency ◽  
Signal To Noise Ratio ◽  
Front Face ◽  
Signal To Noise ◽  
Statistical Effect ◽  
High Detection ◽  
High Detection Efficiency ◽  
Photon Annihilation

We first measured 4- and 5-photon annihilations in positronium using a multiphoton spectrometer (UNI), which consists of 32 NaI(Tl) scintillators with lead shields, each being located on a surface of an icosidodecahedron. The front face of each scintillator is placed at a distance of L = 262 mm from the center of the UNI. With this setup, the detection efficiency of 4- and 5-photon-annihilation processes are too small to get a sufficient number of events to analyze the physics. To obtain a larger detection efficiency, we must set the NaI(Tl) scintillators closer to the target. The original principle in designing the UNI was to suppress backgrounds (BG) and make them as low as possible allowing modest efficiencies for 4- and 5-photon-annihilation events, i.e., to get the highest signal-to-noise ratio (S/N). The new concept is to get the highest S/σ where σ is an error of one standard deviation of the signal including BG effects. A higher S/σ means a larger number of events with smaller BG taking into account a statistical effect. The detection efficiencies with BG effects are studied with respect to L using a detector simulator based on the EGS4 code in which 2- to 5-photon-annihilation events are generated by quantum-electrodynamic processes based on GRACE and BASES/SPRING codes. As a result, the detection efficiency and S/σ of 5-photon annihilations at L = 136 mm are 529 and 17 times larger than those at L = 262 mm, respectively. PACS Nos.: 36.10Dr, 12.20Fv, 13.10+q

Weak Transient Electromagnetic Radiation Signal Detection Method Considering the New Watershed Image Segmentation Algorithm

2019 ◽  
Vol 34 (03) ◽  
pp. 2054009
Author(s):  
Wenjun Huo ◽  
Peng Chu ◽  
Kai Wang ◽  
Liangting Fu ◽  
Zhigang Niu ◽  
...  
Keyword(s):  
Electromagnetic Radiation ◽  
Cross Correlation ◽  
Detection Efficiency ◽  
Signal To Noise Ratio ◽  
Estimation Method ◽  
Detection Methods ◽  
Signal To Noise ◽  
Long Distance ◽  
Transient Electromagnetic ◽  
Noise Ratio

In order to study the detection methods of weak transient electromagnetic radiation signals, a detection algorithm integrating generalized cross-correlation and chaotic sequence prediction is proposed in this paper. Based on the dual-antenna test and cross-correlation information estimation method, the detection of aperiodic weak discharge signals under low signal-to-noise ratio is transformed into the estimation of periodic delay parameters, and the noise is reduced at the same time. The feasibility of this method is verified by simulation and experimental analysis. The results show that under the condition of low signal-to-noise ratio, the integrated method can effectively suppress the influence of 10 noise disturbances. It has a high detection probability for weak transient electromagnetic radiation signals, and needs fewer pulse accumulation times, which improves the detection efficiency and is more suitable for long-distance detection of weak electromagnetic radiation sources.

High detection efficiency neutron sensitive microchannel plate

2013 ◽  
Vol 8 (01) ◽  
pp. P01015-P01015 ◽  
Author(s):  
J Pan ◽  
Y Yang ◽  
Y Tian ◽  
M Zeng ◽  
T Deng ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Microchannel Plate ◽  
High Detection ◽  
High Detection Efficiency

scholarly journals First measurements with the new 3He-filled Monoblock Aluminium Multitube neutron detector developed at the ILL for ANSTO PLATYPUS reflectometer

2020 ◽  
pp. 1-15
Author(s):  
Luis Abuel ◽  
Friedl Bartsch ◽  
Andrew Berry ◽  
Jean-Claude Buffet ◽  
Sylvain Cuccaro ◽  
...  
Keyword(s):  
Research Collaboration ◽  
Detection Efficiency ◽  
Mechanical Design ◽  
Performance Parameters ◽  
Detector Performance ◽  
High Detection ◽  
Neutron Wavelength ◽  
High Detection Efficiency ◽  
Main Detector ◽  
Characterisation Methods

A detector upgrade was carried out on the PLATYPUS instrument dedicated to neutron reflectometry at the Australian Nuclear Science and Technology Organisation (ANSTO). The new detector, developed in the framework of a research collaboration between the ILL and ANSTO, is based on the Monoblock Aluminium Multi-tube (MAM) detector design already in use on several reflectometers and SANS instruments at the ILL. This article provides a technical description of the mechanical design and read-out electronics of the PLATYPUS detector and its commissioning on the PLATYPUS instrument. The main detector performance parameters have been measured and are presented here as well as the characterisation methods and the results of several reflectometry measurements. These measurements show an improvement in experimental data quality resulting from high positional resolution, high detection efficiency and reduced neutron scattering background in the 2.5–19 Å neutron wavelength range used in PLATYPUS instrument.

scholarly journals Potentialities of the future technical improvements in the search of rare nuclear decays by bolometers

2018 ◽  
Vol 33 (09) ◽  
pp. 1843003 ◽  
Author(s):  
Fabio Bellini
Keyword(s):  
Nuclear Physics ◽  
Detection Efficiency ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Particle Identification ◽  
X Ray ◽  
High Detection ◽  
High Detection Efficiency ◽  
Hybrid Devices ◽  
Excellent Energy Resolution

Bolometers are cryogenic calorimeters which feature excellent energy resolution, low energy threshold, high detection efficiency, flexibility in choice of materials, particle identification capability if operated as hybrid devices. After 30 years of rapid progresses, they represent nowadays a leading technology in several fields: particle and nuclear physics, X-ray astrophysics, cosmology. However, further and substantial developments are required to increase the sensitivity to the levels envisioned by future researches. A review of the challenges to be addressed and potentialities of bolometers in the search for rare nuclear decays is given, with particular emphasis to the neutrinoless double beta decay physics case.

Movements of mottled sculpins (Cottus bairdii) in a Michigan stream: how restricted are they?

2009 ◽  
Vol 66 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Matthew J. Breen ◽  
Carl R. Ruetz ◽  
Kurt J. Thompson ◽  
Steven L. Kohler
Keyword(s):  
Home Range ◽  
Standard Error ◽  
Small Proportion ◽  
Detection Efficiency ◽  
Maximum Displacement ◽  
Passive Integrated Transponder ◽  
Seasonal Movement ◽  
High Detection ◽  
High Detection Efficiency ◽  
Movement Distance

We monitored 94 mottled sculpins ( Cottus bairdii ) marked with passive integrated transponder (PIT) tags to examine seasonal movement patterns. High detection efficiency (mean ± standard error = 0.76 ± 0.03) of PIT-tagged fish was obtained with a portable antenna. Nighttime searches were more effective than daytime relocations in summer, and smaller fish (<65 mm) were detected more readily than larger fish (≥65 mm). Sculpins used erosional habitats more than depositional habitats, particularly during summer and nighttime. Search attempts within a 150 m reach showed that displacement, mean movement distance, and home range did not differ significantly between summer and winter, suggesting that season did not strongly influence movement. Additionally, movement metrics were unrelated to sculpin size. However, supplementary searches of a larger reach (700 m) showed that 16% of PIT-tagged fish moved more than 100 m over 1 year, with a maximum displacement of 511 m, and mobile fish typically displayed upstream bias. Although most mottled sculpins in our system were relatively sedentary, a small proportion of individuals moved further than previously reported for other systems.

scholarly journals Comparative Performance of Catalytic Fenton Oxidation with Zero-Valent Iron (Fe(0)) in Comparison with Ferrous Sulphate for the Removal of Micropollutants

2019 ◽  
Vol 9 (11) ◽  
pp. 2181
Author(s):  
Anuradha Goswami ◽  
Jia-Qian Jiang
Keyword(s):  
Standard Deviation ◽  
Signal To Noise Ratio ◽  
Ferrous Sulphate ◽  
Fenton Oxidation ◽  
Zero Valent Iron ◽  
Fenton Process ◽  
Signal To Noise ◽  
Experimental Conditions ◽  
Comparative Performance ◽  
Sludge Production

This research aims to depict the comparative performance of micropollutants’ removal by FeSO4- and zero-valent iron (Fe(0))-catalytic Fenton oxidation and to explore the possibilities of minimising the sludge production from the process. The emerging micropollutants used for the study were gabapentin, sulfamethoxazole, diuron, terbutryn and terbuthylazine. The Taguchi method, which evaluates the signal-to-noise ratio instead of the standard deviation, was used to develop robust experimental conditions. Though both FeSO4- and Fe(0)-catalytic Fenton oxidation were able to completely degrade the stated micropollutants, the Fe(0)-catalytic Fenton process delivered better removal of dissolved organic carbon (DOC; 70%) than FeSO4 catalytic Fenton oxidation (45%). Fe(0)-catalytic Fenton oxidation facilitated heterogeneous treatment functions, which eliminated toxicity from contaminated solution and there was no recognisable sludge production.

NUV Silicon Photomultipliers With High Detection Efficiency and Reduced Delayed Correlated-Noise

2015 ◽  
Vol 62 (3) ◽  
pp. 1318-1325 ◽  
Author(s):  
Fabio Acerbi ◽  
Alessandro Ferri ◽  
Gaetano Zappala ◽  
Giovanni Paternoster ◽  
Antonino Picciotto ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Correlated Noise ◽  
Silicon Photomultipliers ◽  
High Detection ◽  
High Detection Efficiency
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