The apparent teleconnection between cosmic-ray muon flux over a base point in the Caribbean is discussed against the background of an extensive record of indices representing large-scale climatic phenomena, but limite...The apparent teleconnection between cosmic-ray muon flux over a base point in the Caribbean is discussed against the background of an extensive record of indices representing large-scale climatic phenomena, but limited cosmic-ray muon flux data. Many investigators have shown that large-scale climate phenomena influence sub-seasonal and seasonal climate variability, especially in the northern hemisphere and their impacts on the Caribbean are well documented. These climatic phenomena that impact the Caribbean include, but are not limited to, the El Nino Southern Oscillation, the Quasi-Biennial Oscillation, the North Atlantic Oscillation, and the Arctic Oscillation which is now being investigated. Although strong statistical correlation between variables over non-contiguous regions are not absolute as proof of teleconnections, the correlation strength can be used as an indication of its existence. The data gathered at the Mona Campus of the University of the West Indies, in Jamaica, using a simple QuarkNet 6000 muon detector over the period September 2011 to September 2013, showed an apparent significant relationship with these climatic indices. This suggests that cosmic-ray muon flux might be linked to the behavior of the climate phenomena and therefore can be used as a climate or meteorological index over the Caribbean.展开更多
Introduction Cosmic-ray muon imaging is a kind of nondestructive detection technology which can be used to detect unknown objects in geological exploration,civil engineering and nuclear safety.Transmission imaging and...Introduction Cosmic-ray muon imaging is a kind of nondestructive detection technology which can be used to detect unknown objects in geological exploration,civil engineering and nuclear safety.Transmission imaging and scattering tomography schemes are studied.Method The transmission scheme uses a multilayer detector to measure the direction of a cosmic-ray muon passing through an object.The scattering scheme involves placing two detectors upstream and downstream of the object to record the incident and exit directions of the muon passing through the object.The effect of the detector resolution on the imaging clarity of transmission imaging was studied.The applicable scenarios of the two schemes were analyzed.Results The results by calculating show that in the transmission imaging of a hundred-meter object,a spatial resolution of 2.5 m can be achieved,and Cu and Fe can be discriminated with a density difference of 1.1 g/cm3.Scattering tomography is mainly suitable for meter-level objects,which can detect 0.2 m chamber and distinguish 0.05 m heavy metal blocks in rock.展开更多
A recent experimental finding replicated an earlier research result, both of which demonstrated conflict with a specific Standard Model prediction. The “Muon g - 2” studies have indicated that the degree of muon pre...A recent experimental finding replicated an earlier research result, both of which demonstrated conflict with a specific Standard Model prediction. The “Muon g - 2” studies have indicated that the degree of muon precession predicted by the Model is not the same as observed. The researchers offer many posteriori atheoretical hypotheses as possible explanations of their findings, but no fundamental theoretical understanding of the near discovery is among them. This article describes both an explication for the unexpected result and describes its underlying mechanism based on an existing cosmological theory, the Probabilistic Spacetime Theory. The paper also discusses the potential value of this theory.展开更多
This study aimed to investigate the relationship between atmospheric conditions and cosmic ray (CR) muons using daily and monthly CR data collected by the KAAU muon detector in Jeddah, Saudi Arabia between 2007 and 20...This study aimed to investigate the relationship between atmospheric conditions and cosmic ray (CR) muons using daily and monthly CR data collected by the KAAU muon detector in Jeddah, Saudi Arabia between 2007 and 2012. Specifically, the study examined the effects of atmospheric pressure, air temperature, and relative humidity on CR muons at different time scales (annual, seasonal, and monthly). The results of the analysis revealed that atmospheric pressure and air temperature had a negative impact on CR muons, while relative humidity had a positive impact. Although air temperature and relative humidity had small mean values across all time scales, their coefficients varied significantly from month to month and season to season. In addition, the study conducted multivariable correlation analyses for each day, which showed that pressure coefficients had consistently negative mean values, while the temperature and humidity coefficients had varying effects, ranging from positive to negative values. The reasons for the variations in the coefficients are not yet fully understood, but the study proposed several possible terrestrial and extraterrestrial explanations. These findings provide important insights into the complex interactions between the Earth’s atmosphere and cosmic rays, which can contribute to a better understanding of the potential impacts of cosmic rays on the Earth’s climate and environment.展开更多
Muon tomography is a capable imaging technique to measure the geometry of high-Z objects. However,most existed algorithms used in muon tomography have obscured the effects of angular distribution and momentum spectra ...Muon tomography is a capable imaging technique to measure the geometry of high-Z objects. However,most existed algorithms used in muon tomography have obscured the effects of angular distribution and momentum spectra of cosmic ray muons and reduced the spatial resolution. We present a modified multi-group model that takes into account these effects and calibrates the model by the material of lead. Performance tests establish that the model is capable of measuring the thickness of a Pb slab and identifying the material of an unknown slab on a reasonable exposure timescale, in both cases of complete and incomplete angular data. Results show that the modified multi-group model is helpful for improvements in image resolution in real applications.展开更多
Muon scattering tomography is believed to be a promising technique for cargo container inspection, owing to the ability of natural muons to penetrate into dense materials and the absence of artificial radiation. In th...Muon scattering tomography is believed to be a promising technique for cargo container inspection, owing to the ability of natural muons to penetrate into dense materials and the absence of artificial radiation. In this work, the material discrimination ability of muon scattering tomography is evaluated based on experiments at the Tsinghua University cosmic ray muon tomography facility,with four materials: flour(as drugs substitute), aluminum,steel, and lead. The features of the different materials could be discriminated with cluster analysis and classifiers based on support vector machine. The overall discrimination precisions for these four materials could reach 70, 95, and 99% with 1-, 5-, and 10-min-long measurement,respectively.展开更多
文摘The apparent teleconnection between cosmic-ray muon flux over a base point in the Caribbean is discussed against the background of an extensive record of indices representing large-scale climatic phenomena, but limited cosmic-ray muon flux data. Many investigators have shown that large-scale climate phenomena influence sub-seasonal and seasonal climate variability, especially in the northern hemisphere and their impacts on the Caribbean are well documented. These climatic phenomena that impact the Caribbean include, but are not limited to, the El Nino Southern Oscillation, the Quasi-Biennial Oscillation, the North Atlantic Oscillation, and the Arctic Oscillation which is now being investigated. Although strong statistical correlation between variables over non-contiguous regions are not absolute as proof of teleconnections, the correlation strength can be used as an indication of its existence. The data gathered at the Mona Campus of the University of the West Indies, in Jamaica, using a simple QuarkNet 6000 muon detector over the period September 2011 to September 2013, showed an apparent significant relationship with these climatic indices. This suggests that cosmic-ray muon flux might be linked to the behavior of the climate phenomena and therefore can be used as a climate or meteorological index over the Caribbean.
文摘Introduction Cosmic-ray muon imaging is a kind of nondestructive detection technology which can be used to detect unknown objects in geological exploration,civil engineering and nuclear safety.Transmission imaging and scattering tomography schemes are studied.Method The transmission scheme uses a multilayer detector to measure the direction of a cosmic-ray muon passing through an object.The scattering scheme involves placing two detectors upstream and downstream of the object to record the incident and exit directions of the muon passing through the object.The effect of the detector resolution on the imaging clarity of transmission imaging was studied.The applicable scenarios of the two schemes were analyzed.Results The results by calculating show that in the transmission imaging of a hundred-meter object,a spatial resolution of 2.5 m can be achieved,and Cu and Fe can be discriminated with a density difference of 1.1 g/cm3.Scattering tomography is mainly suitable for meter-level objects,which can detect 0.2 m chamber and distinguish 0.05 m heavy metal blocks in rock.
文摘A recent experimental finding replicated an earlier research result, both of which demonstrated conflict with a specific Standard Model prediction. The “Muon g - 2” studies have indicated that the degree of muon precession predicted by the Model is not the same as observed. The researchers offer many posteriori atheoretical hypotheses as possible explanations of their findings, but no fundamental theoretical understanding of the near discovery is among them. This article describes both an explication for the unexpected result and describes its underlying mechanism based on an existing cosmological theory, the Probabilistic Spacetime Theory. The paper also discusses the potential value of this theory.
文摘This study aimed to investigate the relationship between atmospheric conditions and cosmic ray (CR) muons using daily and monthly CR data collected by the KAAU muon detector in Jeddah, Saudi Arabia between 2007 and 2012. Specifically, the study examined the effects of atmospheric pressure, air temperature, and relative humidity on CR muons at different time scales (annual, seasonal, and monthly). The results of the analysis revealed that atmospheric pressure and air temperature had a negative impact on CR muons, while relative humidity had a positive impact. Although air temperature and relative humidity had small mean values across all time scales, their coefficients varied significantly from month to month and season to season. In addition, the study conducted multivariable correlation analyses for each day, which showed that pressure coefficients had consistently negative mean values, while the temperature and humidity coefficients had varying effects, ranging from positive to negative values. The reasons for the variations in the coefficients are not yet fully understood, but the study proposed several possible terrestrial and extraterrestrial explanations. These findings provide important insights into the complex interactions between the Earth’s atmosphere and cosmic rays, which can contribute to a better understanding of the potential impacts of cosmic rays on the Earth’s climate and environment.
基金supported by the Science and Technology Development Foundation of CAEP(No.2015B0103014)the National Natural Science Foundation of China(No.11605163)
文摘Muon tomography is a capable imaging technique to measure the geometry of high-Z objects. However,most existed algorithms used in muon tomography have obscured the effects of angular distribution and momentum spectra of cosmic ray muons and reduced the spatial resolution. We present a modified multi-group model that takes into account these effects and calibrates the model by the material of lead. Performance tests establish that the model is capable of measuring the thickness of a Pb slab and identifying the material of an unknown slab on a reasonable exposure timescale, in both cases of complete and incomplete angular data. Results show that the modified multi-group model is helpful for improvements in image resolution in real applications.
文摘Muon scattering tomography is believed to be a promising technique for cargo container inspection, owing to the ability of natural muons to penetrate into dense materials and the absence of artificial radiation. In this work, the material discrimination ability of muon scattering tomography is evaluated based on experiments at the Tsinghua University cosmic ray muon tomography facility,with four materials: flour(as drugs substitute), aluminum,steel, and lead. The features of the different materials could be discriminated with cluster analysis and classifiers based on support vector machine. The overall discrimination precisions for these four materials could reach 70, 95, and 99% with 1-, 5-, and 10-min-long measurement,respectively.
