A development of a compact software package for systematic error studies in muon g-2/EDM experiment at J-PARC

Won E.,Lee Woodo 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.3

The J-PARC muon g − 2/EDM experiment aims to measure the muon magnetic moment anomaly aμ = (g − 2)∕2 . The target sensitivity for aμ is a statistical uncertainty of 450 × 10−9 , and aμ can be extracted by measuring the spin precession of muons (ωa). The ωa can be extracted from the distribution of muon decay time, and the time is measured by reconstructing tracks of positrons that are decayed from the muons. To extract ωa precisely, the systematic effects on ωa should be controlled under the aforementioned sensitivity. To study systematic effects, we develop a compact simulation package, and using our developed package, we study several systematic effects and discuss the results. We discuss the implementation details of the package and studies of systematic effects on ωa.

A cosmic ray muons tomography system with triangular bar plastic scintillator detectors and improved 3d image reconstruction algorithm: A simulation study

Zhao Yanwei,Luo Xujia,Qin Kemian,Liu Guorui,Chen Daiyuan,Augusto R.S.,Zhang Weixiong,Luo Xiaogang,Liu Chunxian,Liu Juntao,Liu Zhiyi 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.2

Purpose: Muons are characterized by a strong penetrating ability and can travel through thousands of meters of rock, making them ideal to image large volumes and substances typically impenetrable to, for example, electrons and photons. The feasibility of 3D image reconstruction and material identification based on a cosmic ray muons tomography (MT) system with triangular bar plastic scintillator detectors has been verified in this paper. Our prototype shows potential application value and the authors wish to apply this prototype system to 3D imaging. In addition, an MT experiment with the same detector system is also in progress. Methods: A simulation based on GEANT4 was developed to study cosmic ray muons' physical processes and motion trails. The yield and transportation of optical photons scintillated in each triangular bar of the detector system were reproduced. An image reconstruction algorithm and correction method based on muon scattering, which differs from the conventional PoCA algorithm, has been developed based on simulation data and verified by experimental data. Results: According to the simulation result, the detector system’s position resolution is below 1 ~ mm in simulation and 2 mm in the experiment. A relatively legible 3D image of lead bricks in size of 20 cm 5 cm 10 cm used our inversion algorithm can be presented below 1 104 effective events, which takes 16 h of acquisition time experimentally. Conclusion: The proposed method is a potential candidate to monitor the cosmic ray MT accurately. Monte Carlo simulations have been performed to discuss the application of the detector and the simulation results have indicated that the detector can be used in cosmic ray MT. The cosmic ray MT experiment is currently underway. Furthermore, the proposal also has the potential to scan the earth, buildings, and other structures of interest including for instance computerized imaging in an archaeological framework.

Development of a Cosmic-ray Muon Radiography System with Plastic Scintillators

이효상,S. J. Kim,K. Y. Baik,J. K. Ahn 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.5

We demonstrate that cosmic-ray muon radiography is viable for detecting high-Z material. While the health risks from radiation and the cost for better image quality, areserious concerns in envertional radiography cosmic-ray muon radiography is free from radiation risk and is good for three-dimensional imaging. Our simulation study supports the ability to reconstruct high-Z material objects with cosmic-ray muons. We also developed a small-scale muon radiography system with plastic scintillators. The large angular deviation from multiple scattering through a test Pb block shows the feasibility of the cosmic-ray muon radiography system.

A simple model for explaining muon-related anomalies and dark matter

Chiang, Cheng-Wei,Okada, Hiroshi World Scientific Publishing 2019 International Journal of Modern Physics A Vol.34 No.20

<P>We propose a model to explain several muon-related experimental anomalies and the abundance of dark matter. We introduce a vector-like exotic lepton that form an iso-doublet and three right-handed Majorana fermions as an iso-singlet. A real/complex scalar field is added as a dark matter candidate. We impose a global <TEX>$ U(1)_{\mu }$</TEX> symmetry under which fields associated with the SM muon are charged. To stabilize the dark matter, we impose a <TEX>$ Z_{2}$</TEX> (or <TEX>$ Z_{3}$</TEX>) symmetry under which the exotic lepton doublet and the real (or complex) scalar field are charged. We find that the model can simultaneously explain the muon anomalous magnetic dipole moment and the dark matter relic density in no conflict with any lepton flavor-violating/conserving observables, with some details depending upon whether the scalar field is real or complex. Besides, we extend the framework to the quark sector in a way similar to the lepton sector, and find that the recent anomalies associated with the <TEX>$ b \rightarrow s\mu ^{+}\mu ^{-}$</TEX> transition can also be accommodated while satisfying constraints such as the <TEX>$ B_{s(d)} \rightarrow \mu ^{+}\mu ^{-}$</TEX> decays and neutral meson mixings.</P>

우주선 뮤온 검출을 위한 CAU 다선비례검출기 설계와 제작

이지훈,김태현,남기환,박현정,송두리,신재철,오민기,이종훈,이필수,진경환,김시연 한국물리학회 2012 새물리 Vol.62 No.6

We designed and constructed a multi-wire proportional chamber to detect cosmic-ray muons. The main body of the detector is a stainless-steel chamber containing a mixture of Ar and CO_2 gases. When an incident muon hits an Ar molecule, an electron produced by ionization generates a subsequent ionization of Ar, resulting in an electron avalanche identified as a signal. The charge division method is adopted to determine the position through which a muon passes. In this paper, we explain the manufacturing process and introduce the specifications for the detector and its components to obtain signals on the display of an oscilloscope. 우주선-뮤온을 검출하기 위한 다선비례검출기를 제작하였다. 이 검출기는스테인레스 챔버에 아르곤과 이산화탄소의 혼합개스를 채우고, 뮤온이기체분자와 충돌한 다음 이온화과정에서 유도된 전자사태가 만드는신호를 검출한다. 전하분리법을 적용하여, 뮤온이 지나간 지점을 관측할수 있도록 하였다. 제작 과정및 오실로스코프에서 신호를 성공적으로검출하도록 선택된 회로의 사양을 소개한다.

Cryogenic system for COMET experiment at J-PARC

Ki, T.,Yoshida, M.,Yang, Y.,Ogitsu, T.,Iio, M.,Makida, Y.,Okamura, T.,Mihara, S.,Nakamoto, T.,Sugano, M.,Sasaki, K.i. Heywood Co ; Elsevier Science Ltd 2016 Cryogenics Vol.77 No.-

Superconducting conductors and cryogenic refrigeration are key factors in the accelerator science because they enable the production of magnets needed to control and detect the particles under study. In Japan, a system for COMET (Coherent Muon to Electron Transition), which will produce muon beam lines, is under the construction at J-PARC (Japan Proton Accelerator Research Complex). The system consists of three superconducting magnets; the first is a pion-capture solenoid, the second is a muon-transport solenoid, and the third is a detector solenoid. It is necessary to cool down the magnets efficiently using two-phase helium and maintain them securely at 4.5K. For stable cryogenic refrigeration of the magnets, a suitable cooling method, structures, and the irradiation effect on materials should be investigated. In this paper, we focus on the development of an overall cryogenic system for cooling the capture and transport solenoids. A conduction-cooling method is considered for cooling the capture and transport solenoids because of the advantages such as the reduction of total heat load, fewer components, and simplified structure. To supply cryogenic fluids (4.5K liquid helium and 58K gas helium) and currents to the conduction-cooled magnets subjected to high irradiation, cryogenic components (cooling paths in the magnets, transfer tubes, and a current lead box) are developed. Based on the environment of high irradiation, the conditions (temperature and pressure) of helium in cooling paths are estimated, as well as the temperature of the capture magnet. We develop a dynamic model for quench simulation and estimate the maximum pressure in the cooling pipe when the capture magnet quenches. We conclude with a discussion of the next steps and estimated challenges for the cryogenic system.

A search for pair production of new light bosons decaying into muons in proton-proton collisions at 13 TeV

Sirunyan, A.M.,Tumasyan, A. North-Holland Pub. Co 2019 Physics letters. Section B Vol.796 No.-

<P><B>Abstract</B></P> <P>A search for new light bosons decaying into muon pairs is presented using a data sample corresponding to an integrated luminosity of 35.9 <SUP> fb − 1 </SUP> of proton-proton collisions at a center-of-mass energy s = 13 TeV , collected with the CMS detector at the CERN LHC. The search is model independent, only requiring the pair production of a new light boson and its subsequent decay to a pair of muons. No significant deviation from the predicted background is observed. A model independent limit is set on the product of the production cross section times branching fraction to dimuons squared times acceptance as a function of new light boson mass. This limit varies between 0.15 and 0.39fb over a range of new light boson masses from 0.25 to 8.5 GeV. It is then interpreted in the context of the next-to-minimal supersymmetric standard model and a dark supersymmetry model that allows for nonnegligible light boson lifetimes. In both cases, there is significant improvement over previously published limits.</P>

Development of a muon detector based on a plastic scintillator and WLS fibers to be used for muon tomography system

박찬우,김규범,백민규,강인수,이성연,정윤수,정희준,정용현 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.3

Muon tomography is a useful method for monitoring special nuclear materials (SNMs) such as spent nuclear fuel inside dry cask storage. Multiple Coulomb scattering of muons can be used to provide information about the 3-dimensional structure and atomic number(Z) of the inner materials. Tomography using muons is less affected by the shielding material and less harmful to health than other measurement methods. We developed a muon detector for muon tomography, which consists of a plastic scintillator, 64 long wavelength-shifting (WLS) fibers attached to the top of the plastic scintillator, and silicon photomultipliers (SiPMs) connected to both ends of each WLS fiber. The muon detector can acquire X and Y positions simultaneously using a position determination algorithm. The design parameters of the muon detector were optimized using DETECT2000 and Geant4 simulations, and a muon detector prototype was built based on the results. Spatial resolution measurement was performed using simulations and experiments to evaluate the feasibility of the muon detector. The experimental results were in good agreement with the simulation results. The muon detector has been confirmed for use in a muon tomography system.

Image reconstruction algorithm for momentum dependent muon scattering tomography

Bae JungHyun,Montgomery Rose,Chatzidakis Stylianos 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.5

Nondestructive radiography using cosmic ray muons has been used for decades to monitor nuclear reactor and spent nuclear fuel storage. Because nuclear fuel assemblies are highly dense and large, typical radiation probes such as x-rays cannot penetrate these target imaging objects. Although cosmic ray muons are highly penetrative for nuclear fuels as a result of their relatively high energy, the wide application of muon tomography is limited because of naturally low cosmic ray muon flux. This work presents a new image reconstruction algorithm to maximize the utility of cosmic ray muon in tomography applications. Muon momentum information is used to improve imaging resolution, as well as muon scattering angle. In this work, a new convolution was introduced known as M-value, which is a mathematical integration of two measured quantities: scattering angle and momentum. It captures the objects’ quantity and density in a way that is easy to use with image reconstruction algorithms. The results demonstrate how to reconstruct images when muon momentum measurements are included in a typical muon scattering tomography algorithm. Using M-value improves muon tomography image resolution by replacing the scattering angle value without increasing computation costs. This new algorithm is projected to be a standard nondestructive radiography technique for spent nuclear fuel and nuclear material management.

Characterization of the atmospheric muon flux in IceCube

Aartsen, M.G.,Abraham, K.,Ackermann, M.,Adams, J.,Aguilar, J.A.,Ahlers, M.,Ahrens, M.,Altmann, D.,Anderson, T.,Archinger, M.,Arguelles, C.,Arlen, T.C.,Auffenberg, J.,Bai, X.,Barwick, S.W.,Baum, V.,Bay North-Holland ; Elsevier Science Ltd 2016 Astroparticle physics Vol.78 No.-

<P>Muons produced in atmospheric cosmic ray showers account for the by far dominant part of the event yield in large-volume underground particle detectors. The IceCube detector, with an instrumented volume of about a cubic kilometer, has the potential to conduct unique investigations on atmospheric muons by exploiting the large collection area and the possibility to track particles over a long distance. Through detailed reconstruction of energy deposition along the tracks, the characteristics of muon bundles can be quantified, and individual particles of exceptionally high energy identified. The data can then be used to constrain the cosmic ray primary flux and the contribution to atmospheric lepton fluxes from prompt decays of short-lived hadrons. In this paper, techniques for the extraction of physical measurements from atmospheric muon events are described and first results are presented. The multiplicity spectrum of TeV muons in cosmic ray air showers for primaries in the energy range from the knee to the ankle is derived and found to be consistent with recent results from surface detectors. The single muon energy spectrum is determined up to PeV energies and shows a clear indication for the emergence of a distinct spectral component from prompt decays of short-lived hadrons. The magnitude of the prompt flux, which should include a substantial contribution from light vector meson di-muon decays, is consistent with current theoretical predictions. The variety of measurements and high event statistics can also be exploited for the evaluation of systematic effects. In the course of this study, internal inconsistencies in the zenith angle distribution of events were found which indicate the presence of an unexplained effect outside the currently applied range of detector systematics. The underlying cause could be related to the hadronic interaction models used to describe muon production in air showers. (C) 2016 Elsevier B.V. All rights reserved.</P>