C. F. Feng
A5029861487- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Gamma-ray bursts and supernovae
- Radiation Therapy and Dosimetry
- Neutrino Physics Research
- Particle Accelerators and Free-Electron Lasers
- Solar and Space Plasma Dynamics
- High-Energy Particle Collisions Research
- Radio Astronomy Observations and Technology
- Quantum Chromodynamics and Particle Interactions
- Radiation Detection and Scintillator Technologies
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Ionosphere and magnetosphere dynamics
- Lightning and Electromagnetic Phenomena
- Earthquake Detection and Analysis
- Atmospheric aerosols and clouds
- Ultrasound and Hyperthermia Applications
- Astro and Planetary Science
- Satellite Communication Systems
- Precipitation Measurement and Analysis
- Endometrial and Cervical Cancer Treatments
- Intraperitoneal and Appendiceal Malignancies
Shandong University
2012-2024
Zhejiang Environmental Monitoring Center
2024
Dalian Medical University
2023-2024
Chongqing Medical University
2023-2024
Second Affiliated Hospital of Chongqing Medical University
2023-2024
Yantai University
2024
Harbin Engineering University
2024
National University of Defense Technology
2024
Tibet University
2007
Hirosaki University
2006
We report on the highest energy photons from Crab Nebula observed by Tibet air shower array with underground water-Cherenkov-type muon detector array. Based criterion of a number measured in an shower, we successfully suppress 99.92% cosmic-ray background events energies E>100 TeV. As result, 24 photonlike TeV against 5.5 events, which corresponds to 5.6σ statistical significance. This is first detection astrophysical source.
The intensity of Galactic cosmic rays is nearly isotropic because the influence magnetic fields in Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using large data sample Tibet Air Shower Arrays. Besides revealing finer details known anisotropies, new component ray sidereal time uncovered around Cygnus region direction. For cosmic-ray up TeV, all components anisotropies fade away, showing...
The measurement of cosmic ray energy spectra, in particular for individual species, is an essential approach finding their origin. Locating the "knees" spectra important part and has yet to be achieved. Here we report a mixed Hydrogen Helium spectrum using combination ARGO-YBJ experiment prototype Cherenkov telescope LHAASO experiment. A knee feature at 640+/-87 TeV, with clear steepening spectrum, observed. This gives fundamental inputs galactic acceleration models.
Measuring the anisotropy of arrival direction distribution cosmic rays provides important information on propagation mechanisms and identification their sources. In fact, flux is thought to be dependent only due presence nearby ray sources or particular magnetic-field structures. Recently, observation unexpected excesses at TeV energy down an angular scale as narrow $\ensuremath{\sim}10\ifmmode^\circ\else\textdegree\fi{}$ raised possibility that problem origin Galactic may addressed by...
Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called shadow). The shadow an important tool to determine performance of air shower array. Indeed, westward displacement center, due bending effect geomagnetic field on propagation cosmic rays, allows setting absolute rigidity scale primary particles inducing showers recorded detector. In addition, shape permits detector point spread function, while position at high energies evaluation pointing accuracy....
The extended TeV gamma-ray source ARGO J2031+4157 (or MGRO J2031+41) is positionally consistent with the Cygnus Cocoon discovered by Fermi-LAT at GeV energies in superbubble. Reanalyzing ARGO-YBJ data collected from 2007 November to 2013 January, angular extension and energy spectrum of are evaluated. After subtracting contribution overlapping sources, excess map fitted a two-dimensional Gaussian function square region 10° × 10°, finding σext= 18 ± 05. observed differential dN/dE = (2.5 0.4)...
The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying northern γ-ray sky energies above 10 TeV with unprecedented sensitivity. observations have long been one most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by decays heavy particles. In this Letter, we present first analysis LHAASO-KM2A, using 340 days data from 1/2-KM2A and 230 3/4-KM2A. Several regions interest are used to search a signal...
The proton-air cross section in the energy range 1--100 TeV has been measured by ARGO-YBJ cosmic ray experiment. analysis is based on primary flux attenuation for different atmospheric depths (i.e. zenith angles) and exploits detector capabilities of selecting shower development stage means hit multiplicity, density lateral profile measurements at ground. effects fluctuations, contribution heavier primaries uncertainties hadronic interaction models, have taken into account. results used to...
We report the observation of TeV gamma-rays from Cygnus region using ARGO-YBJ data collected 2007 November to 2011 August. Several sources are located in this including two bright extended MGRO J2019+37 and J2031+41. According Milagro set, at 20 is most significant source apart Crab Nebula. No signal detected by experiment, derived flux upper limits 90% confidence level for all events above 600 GeV with medium energy 3 lower than flux, implying that might be variable hard identified as a...
The ARGO-YBJ experiment detects extensive air showers in a wide energy range by means of full-coverage detector which is stable data taking its full configuration since November 2007 at the YBJ International Cosmic Ray Observatory (4300 m a.s.l., Tibet, People's Republic China). In this paper measurement light-component spectrum primary cosmic rays region $(5\textdiv{}200)\text{ }\text{ }\mathrm{TeV}$ reported. method exploited to analyze experimental based on Bayesian procedure. measured...
We report on a clear solar-cycle variation of the Sun's shadow in 10 TeV cosmic-ray flux observed by Tibet air shower array during full solar cycle from 1996 to 2009. In order clarify physical implications variation, we develop numerical simulations shadow, using potential field source surface model and current sheet (CSSS) for coronal magnetic field. find that intensity deficit simulated is very sensitive structure, better reproduced CSSS model. This first successful attempt evaluate models flux.
The ARGO-YBJ experiment is a full-coverage air shower detector located at the Yangbajing Cosmic Ray Observatory (Tibet, People's Republic of China, 4300 m a.s.l.). high altitude, combined with technique, allows detection extensive showers in wide energy range and offer possibility measuring cosmic ray proton plus helium spectrum down to TeV region, where direct balloon/space-borne measurements are available. has been stable data taking its full configuration from November 2007 February 2013....
A correlation between the secondary cosmic ray flux and near-earth electric field intensity, measured during thunderstorms, has been found by analyzing data of ARGO-YBJ experiment, a full coverage air shower array located at Yangbajing Cosmic Ray Laboratory (4300 m a. s. l., Tibet, China). The counting rates showers with different particle multiplicities (m=1, 2, 3, ≥4) have to be strongly dependent upon intensity polarity course 15 thunderstorms. In negative fields (i.e., accelerating...
Cosmic ray antiprotons provide an important probe to study the cosmic propagation in interstellar space and investigate existence of dark matter. Acting Earth-Moon system as a magnetic spectrometer, paths primary are deflected opposite sense with respect those protons their way Earth. This effect allows, principle, search for antiparticles direction observed deficit rays due Moon (the so-called "Moon shadow"). The ARGO-YBJ experiment, located at Yangbajing Ray Laboratory (Tibet, P.R. China,...
The ARGO-YBJ detector, located at the Yangbajing Cosmic Ray Laboratory (4300 m a. s. l., Tibet, China), was a "full coverage" air shower array. high altitude location and frequent occurrence of thunderstorms, made suitable to study effects atmospheric electric fields (AEF) on secondary cosmic rays. By analyzing data detector recorded during significant variations rate detected showers have been observed. During 20 thunderstorm episodes in 2012, rates (both increases decreases amplitudes up...
Data from the Tibet III air shower array (with energies around 3 TeV) and II 10 have been searched for diffuse gamma rays Galactic plane. These arrays an angular resolution of about 09. The sky regions are inner Galaxy, 20° ≤ l 55°, outer 140° 225°, |b| 2° or 5°. No significant Galactic-plane gamma-ray excess was observed. 99% confidence level upper limits intensity obtained (for 2°) 1.1 × 10-15 cm-2 s-1 sr-1 MeV-1 at TeV 4.1 10-17 3.6 10-16 1.3 assuming a differential spectral index 2.4. in...
The Wide Field-of-View Cherenkov Telescope Array (WFCTA) and the Water Detector Arrays (WCDA) of LHAASO are designed to work in combination for measuring energy spectra various cosmic ray species over a very wide range from few TeV 10 PeV. calibration WCDA can be achieved with proven technique westward shift Moon shadow galactic rays due geomagnetic field. This deflection angle $\Delta$ is inversely proportional rays. precise measurements shifts by allows us calibrate its scale energies as...
Abstract The ARGO-YBJ detector, located at the Yangbajing Cosmic Ray Laboratory (4300 m a. s. l., Tibet, China), was a “full coverage” (central carpet with an active area of ∼93%) air shower array dedicated to gamma-ray astronomy and cosmic-ray studies. wide field view (∼2 sr) high duty cycle (>86%), made suitable search for short unexpected emissions like bursts (GRBs). Between 2007 November 6 2013 February 7, 156 satellite-triggered GRBs (24 them known redshift) occurred within (zenith...
The search for Gamma Ray Burst (GRB) emission in the energy range 1-100 GeV coincidence with satellite detection has been carried out using Astrophysical Radiation Ground-based Observatory at YangBaJing (ARGO-YBJ) experiment. high altitude location (4300 m a.s.l.), large active surface ($\sim$ 6700 m$^2$ of Resistive Plate Chambers), wide field view ($\sim 2~$sr, limited only by atmospheric absorption) and duty cycle ($>$ 86 %) make ARGO-YBJ experiment particularly suitable to detect short...
We analyze the Sun's shadow observed with Tibet-III air shower array and find that shadow's center deviates northward (southward) from optical solar disk in "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing numerical simulations based on model, we average IMF strength away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than model prediction. These demonstrate a useful tool for quantitative evaluation of field.