检索结果-内蒙古大学图书馆

Design and Test of SiPM Readout Circuit 38

学校读者我要写书评

暂无评论

Design and Test of SiPM Readout Circuit

38th International Cosmic Ray Conference, ICRC 2023

作者： Li, Kefan Yang, Mingjie Zhang, Shoushan Chen, Long Zhu, Fengrong Southwest Jiaotong University School of Physical Science and Technology No. 999 Xi’an Road Chengdu China Institute of High Energy Physics Chinese Academy of Sciences Key Laboratory of Particle Astrophysics & Experimental Physics Division & Computing Center No. 19B Yuquan Road Beijing China Institute of High Energy Physics Chinese Academy of Sciences TIANFU Cosmic Ray Research Center No. 1500 Kezhi Road Chengdu China

Silicon photomultiplier (SiPM) have several advantages such as high photon detection efficiency, wide spectral response range, high gain at low bias voltage and compact structure. In addition, SiPM is not damaged by high night sky background (NSB) level, which means that SiPM is a good choice for the atmospheric Atmosphere Cherenkov experiment such as LHAASO-WFCTA and The Cherenkov Telescope Array (CTA) . However, the quenching resistor and capacitor inside SiPM will lead to a longer recovery when a photon casuses avalanche inside SiPM, and then the pusle generated always has a much longer fall time than PMT. This work proposes a passive shaping circuit based on pole-zero cancellation circuit to realize the narrow pulse readout for SiPM without increasing power supply and the output pulse width has been reduced to under than 50 ns with the type of HAMAMATSU-S14466 and the size of 15 mm ×15 mm in the lab, when SiPM is illuminated by the 10 ns pulsed light. © Copyright owned by the author(s) under the terms of the Creative Commons.

关键词： Photons

Discovery of the Ultra-High-Energy gamma-ray source LHAASO J2002+3238 spatially associated with SNR G69.7+1.0 38

学校读者我要写书评

暂无评论

Discovery of the Ultra-High-Energy gamma-ray source LHAASO J...

38th International Cosmic Ray Conference, ICRC 2023

作者： Hou, B.W. Zhang, R. Xi, S.Q. Chen, S.Z. He, H.N. Xia, Z.Q. Key Laboratory of Particle Astrophyics & Experimental Physics Division & Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China University of Chinese Academy of Sciences Beijing100049 China Tianfu Cosmic Ray Research Center Sichuan Chengdu610000 China University of Science and Technology of China Hefei230026 China Key Laboratory of Dark Matter and Space Astronomy Key Laboratory of Radio Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing210023 China

The origin of Galactic PeV cosmic rays is still under debate. Shell-type supernova remnants (SNRs) are proposed to be one of the candidate sources of Galactic PeV cosmic rays, but observational evidence is lacking. Here we report LHAASO’s detection on a point source J2002+3238 with a significance of 5.8 sigma above 25 TeV and 6.8 sigma above 100 TeV. The spectrum is consistent with a power-law spectrum with no cutoff. Inside the error region of the source, a shell-type SNR G69.7+1.0 is found locating only 0.07◦away from the best-fit location of the source, suggesting a strong association between the UHE gamma-ray source and the SNR. This provides strong evidence on SNRs as possible PeV accelerators. © Copyright owned by the author(s) under the terms of the Creative Commons.

关键词： Cosmic rays

Detection of a new GeV source in the outer region of the Coma cluster: a signature of external accretion shock ?

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Chen, Xiao-Bin Wang, Kai Huang, yi-Yun Zhang, Hai-Ming Xi, Shao-Qiang Liu, Ruo-Yu Wang, Xiang-Yu School of Astronomy and Space Science Nanjing University Nanjing210023 China Ministry of Education Nanjing210023 China Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and Technology Guangxi University Nanning530004 China Key Laboratory of Particle Astrophysics & Experimental Physics Division & Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China

The supersonic flow motions associated with infall of baryonic gas toward sheets and filaments, as well as cluster mergers, produces large-scale shock waves. The shocks associated with galaxy clusters can be classified mainly into two categories: internal shocks appear in the hot intracluster medium within the viral radius, and external accretion shocks form in the outer cold region well outside of the virial radius. Cosmic-ray (CR) electrons and/or protons accelerated by these shocks are expected to produce gamma-rays through inverse-Compton scatterings (ICS) or inelastic pp collisions respectively. Recent studies have found a spatially extended GeV source within the virial radius, consistent with the internal shock origin. Here we report the detection of a new GeV source at a distance of about 2.8◦ from the center of the Coma cluster through the analysis of 16.2 years of Fermi-LAT data. The hard spectrum of the source, in agreement with the ICS origin, and its location in a large-scale filament of galaxies points to the external accretion shock origin. The gamma-ray (0.1 − 103 GeV) luminosity of the source, 1.4 × 1042 erg s−1, suggests that a fraction ∼ 10−3 of the kinetic energy flux through the shock-surface is transferred to relativistic CR electrons. © 2024, CC BY.

关键词： Cosmic rays

Search for neutrino emission from the Cygnus Bubble based on LHAASO γ-ray observations

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Li, Wenlian Huang, Tian-Qi Xu, Donglian He, Huihai Tsung-Dao Lee Institute Shanghai Jiao Tong University Shanghai201210 China Key Laboratory of Particle Astrophysics and Experimental Physics Division and Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China TIANFU Cosmic Ray Research Center Sichuan Chengdu China Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai200240 China University of Chinese Academy of Sciences Beijing100049 China

The Cygnus region, which contains massive molecular and atomic clouds and young stars, is a promising Galactic neutrino source candidate. Cosmic rays transport in the region can produce neutrinos and γ-rays. Recently, the Large High Altitude Air Shower Observatory (LHAASO) detected an ultrahigh-energy γ-ray bubble (Cygnus Bubble) in this region. Using publicly available track events detected by the IceCube Neutrino Observatory in 7 years of full detector operation, we conduct searches for correlated neutrino signals from the Cygnus Bubble with neutrino emission templates based on LHAASO γ-ray observations. No significant signals were found for any employed templates. With the 7 TeV γ-ray flux template, we set a flux upper limit of 90% confidence level (C.L.) for the neutrino emission from the Cygnus Bubble to be 5.7 × 10−13 TeV−1cm−2s−1 at 5 TeV. © 2024, CC BY.

关键词： Cosmic rays

由超拍电子伏特加速器产生的超高能伽马射线气泡

学校读者我要写书评

暂无评论

Science Bulletin 2024年第4期69卷 449-457页

作者： LHAASO Collaboration Zhen Cao Chuandong Gao Cong Li Ruo-Yu Liu Ruizhi Yang 不详 Key Laboratory of Particle Astrophyics&Experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China TIANFU Cosmic Ray Research Center ChengduChina Institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China University of Science and Technology of China Hefei 230026China

We report the detection of aγ-ray bubble spanning at least 100deg2 in ultra-high energy(UHE)up to a few PeV in the direction of the star-forming region Cygnus X,implying the presence super PeVatron(s)accelerating protons to at least 10 PeV.A log-parabola form with the photon indexΓ(E)=(2.71±0.02)+(0.11±0.02)×log10(E/10 TeV)is found fitting the gamma-ray energy spectrum of the bubble *** sources,“hot spots”correlated with very massive molecular clouds,and a quasi-spherical amorphousγ-ray emitter with a sharp central brightening are observed in the *** the core of~0.5°,spatially associating with a region containing massive OB association(Cygnus OB2)and a microquasar(Cygnus X-3),as well as previously reported multi-TeV sources,an enhanced concentration of UHEγ-rays is observed with 2 photons at energies above 1 *** general feature of the bubble,the morphology,and the energy spectrum,are reasonably reproduced by the assumption of a particle accelerator in the core,continuously injecting protons into the ambient medium.

关键词： Cosmic rays γ-rays Interstellar medium Star cluster

Determining the Origin of Very-high-energy Gamma Rays from Galactic Sources by Future Neutrino Observations

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Song, Bo-Heng Huang, Tian-Qi Wang, Kai Department of Astronomy School of Physics Huazhong University of Science and Technology Wuhan430074 China Key Laboratory of Particle Astrophysics and Experimental Physics Division Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Tianfu Cosmic Ray Research Center Sichuan Chengdu610000 China

Recently, the Large High Altitude Air Shower Observatory (LHAASO) identified 12 γ-ray sources emitting gamma rays with energies above 100 TeV, making them potential PeV cosmic-ray accelerators (PeVatrons). Neutrino observations are crucial in determining whether the gamma-ray radiation process is of hadronic or leptonic origin. In this paper, we study three detected sources, LHAASO J1908+0621, LHAASO J2018+3651, and LHAASO J2032+4102, which are also the most promising galactic high-energy neutrino candidate sources with the lowest pre-trial p-value based on the stacking searches testing for excess neutrino emission by IceCube Neutrino Observatory. We study the lepto-hadronic scenario for the observed multiband spectra of these LHAASO sources considering the possible counterpart source of the LHAASO sources. The very-high-energy gamma rays are entirely attributed to the hadronic contribution, therefore the most optimistic neutrino flux can be derived. Then, we evaluate the statistical significance (p-value) as a function of observation time of IceCube and the next-generation IceCube-Gen2 neutrino observatory respectively. Our results tend to disfavor that all gamma rays above 100 GeV from LHAASO J1908+0621 are of purely hadronic origin based on current IceCube observations, but the purely hadronic origin of gamma rays above 100 TeV is still possible. By IceCube-Gen2, the origin of gamma rays above 100 TeV from LHAASO J1908+0621 can be further determined at a 5σ significance level within a running time of ∼ 3 years. For LHAASO J2018+3651 and LHAASO J2032+4102, the required running time of IceCube-Gen2 is ∼ 10 years (3σ) and ∼ 10 years (5σ), respectively. Future observations by the next-generation neutrino telescope will be crucial to understanding the particle acceleration and radiation processes inside the sources. © 2023, CC BY.

关键词： Gamma rays

Chapter 1 LHAASO Instruments and Detector technology

学校读者我要写书评

暂无评论

Chinese physics C 2022年第3期46卷 1-35页

作者： Xin-Hua Ma Yu-Jiang Bi Zhen Cao Ming-Jun Chen Song-Zhan Chen Yao-Dong Cheng Guang-Hua Gong Min-Hao Gu Hui-Hai He Chao Hou Wen-Hao Huang Xing-Tao Huang Cheng Liu Oleg Shchegolev Xiang-Dong Sheng Yuri Stenkin Chao-Yong Wu Han-Rong Wu Sha Wu Gang Xiao Zhi-Guo Yao Shou-Shan Zhang Yi Zhang Xiong Zuo Key Laboratory of Particle Astrophyics&Experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China TIANFU Cosmic Ray Research Center ChengduSichuanChina University of Chinese Academy of Sciences Beijing 100049China Department of Engineering Physics Tsinghua UniversityBeijing 100084China Institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237ShandongChina Institute for Nuclear Research of Russian Academy of Sciences Moscow 117312Russia Moscow Institute of Physics and Technology Moscow 141700Russia Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023JiangsuChina

The Large High Altitude Air Shower Observatory(LHAASO)(Fig.1)is located at ***(4410 m a.s.l.,600 g/cm^(2),29°21'27.56"N,100°08'19.66"E)in Daocheng,Sichuan province,*** consists of 1.3 km^(2) array(KM2A)of electromagnetic particle detectors(ED)and muon detectors(MD),a water Cherenkov detector array(WCDA)with a total active area of 78,000 m^(2),18 wide field-of-view air Cherenkov telescopes(WFCTA)and a newly proposed electron-neutron detector array(ENDA)covering 10,000 m^(2).Each detector is synchronized with all the other through a clock synchronization network based on the White Rabbit *** observatory includes an IT center which comprises the data acquisition system and trigger system,the data analysis *** this Chapter,all the above-mentioned components of LHAASO as well as infrastructure are described.

关键词： LHAASO gamma ray astronomy cosmic ray physics

Testing and analysis of the plastic scintillator units for LHAASO-ED

学校读者我要写书评

暂无评论

Radiation Detection Technology and Methods 2021年第4期5卷 513-519页

作者： Ya-Ping Wang Chao Hou Xiang-Dong Sheng Shao-Hui Feng Hong-Kui Lv Jia Liu Jing Zhao Xiao-Peng Zhang Quan-Bu Gou Key Laboratory of Particle Astrophyics&Experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China TIANFU Cosmic Ray Research Center ChengduSichuanChina

Background A total of 5195 electromagnetic particle detectors(EDs)are used in the 1-square-kilometer extensive air shower array(KM2A),which is a subarray of the Large High Altitude Air Shower Observatory(LHAASO).Purpose As the detection sensitive medium of the EDs,more than 20,000 plastic scintillator units(BC-408),produced by Saint-Gobain,are used in *** is important to monitor the light output of the scintillator units among the *** To improve the efficiency,a sampling inspection scheme(misjudgment rate of less than 5%)was designed,and a batch test system was *** units of scintillator units can be measured at a *** test system selects the single muon events of cosmic rays to measure the light output values of the plastic scintillator *** The measurement has an uncertainty of less than 2%.By pretest calibration,the difference between different channels can be *** calibration was implemented approximately every 3 months,and the test system had been running stably for 28 *** measuring the ratio of the signals of selected far and near probe events,the changes in the quality of different batches of plastic scintillator units can be *** The test system realized accurate measurement of the light output,and all batches satisfied the requirements of the experiment.

关键词： LHAASO ED Plastic scintillator unit Light output

Search for neutrino signals correlated with LHAASO diffuse Galactic emission

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Li, Wenlian Huang, Tian-Qi Xu, Donglian He, Huihai Tsung-Dao Lee Institute Shanghai Jiao Tong University Shanghai201210 China Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai200240 China Key Laboratory of Particle Astrophysics and Experimental Physics Division and Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China TIANFU Cosmic Ray Research Center Sichuan Chengdu China School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China University of Chinese Academy of Sciences Beijing100049 China

The diffuse Galactic γ-ray emission originates from the interactions between cosmic rays and the interstellar medium or radiation fields within our Galaxy, where the production of neutrinos is also anticipated. Recently, the Large High Altitude Air Shower Observatory (LHAASO) reported measurements of diffuse γ-rays from the Galactic plane with energies ranging from sub-TeV to 1 PeV. Using publicly available 7 years of IceCube track data with the full detector, we conduct a template search using the γ-ray flux map observed by LHAASO-KM2A as the neutrino emission template and perform a scan search of the Galactic plane. In the template search, a mild excess of neutrinos is observed in the Galactic plane with a pretrial (posttrial) significance of 1.9σ (1.1σ). The measured muon neutrino intensity at 25 TeV is 4.73+2.53−251 × 10−14 TeV−1 cm−2 s−1 sr−1, consistent with the expected neutrino flux assuming that all the diffuse Galactic γ-rays originate from hadronic interactions. In the Galactic plane scan search, the most significant location is found at l = 63.57◦ and b = 0.93◦ with a pretrial (posttrial) significance of 4.6σ (1.8σ). © 2024, CC BY.

关键词： Gamma rays