A novel trigger algorithm for wide-field-of-view imaging atmospheric Cherenkov technique experiments

Xin, G. G.; Cai, H.; Guo, Yi-Qing; Chen, Tianlu; Cheng, Liu; Qian, Xiang-Li

doi:10.1007/s41365-022-01003-3

Cited by 5 publications

(3 citation statements)

References 29 publications

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“…In the simulation phase, the camera was assigned the following trigger algorithm: if the number of photons gathered by a single PMT within a time window of 20 ns was 9, it was considered to have been triggered; if the number of adjacent PMTs triggered was 3, the telescope was considered to have been triggered; and if the number of telescopes triggered was 2, the array was deemed to have been triggered (Xin et al 2022). For high-energy events, the single PMT trigger threshold was higher (Colin et al 2009).…”

Section: Simulationmentioning

confidence: 99%

Gamma/Hadron Separation Method for the HADAR Experiment

Ren,

Chen,

Feng

et al. 2024

Res. Astron. Astrophys.

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Ground-based arrays of imaging atmospheric Cherenkov telescopes (IACTs) are the most sensitive γ-ray detectors for energies of approximately 100 GeV and above. One such IACT is the High Altitude Detection of Astronomical Radiation (HADAR) experiment,which uses a large aperture refractive water lens system to capture atmospheric Cherenkov photons (i.e., the imaging atmospheric Cherenkov technique). The telescope array has a low threshold energy and large field of view, and can continuously scan the area of the sky being observed, which is conducive to monitoring and promptly responding to transient phenomena. The process of γ-hadron separation is essential in very-high-energy (VHE; >30 GeV) γ-ray astronomy and is a key factor for the successful utilization of IACTs. In this study, Monte Carlo (MC) simulations were carried out to model the response of cosmic rays within the HADAR detectors. By analyzing the Hillas parameters and the distance between the event core and the telescope, the distinction between air showers initiated by γ rays and those initiated by cosmic rays was determined. Additionally, a Quality Factor was introduced to assess the telescope’s ability to suppress the background and to provide a more effective characterization of its performance.

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Section: Simulationmentioning

confidence: 99%

Gamma/Hadron Separation Method for the HADAR Experiment

Ren,

Chen,

Feng

et al. 2024

Res. Astron. Astrophys.

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“…4. We believe this is due to the triggering process, where, in order to reduce contamination from night sky background and starlight, we fixed the triggering window to the size of 10 × 10 pixels of the PMT (Xin et al 2022), considering only the distribution and counting of photons within the triggering window, leading to incomplete imaging and degraded reconstruction for highenergy events. This triggering method does not fully utilize the advantage of HADAR's large imaging area.…”

Section: Experimental Sensitivitymentioning

confidence: 99%

Study of the Observation Sensitivity of Gamma-Ray Bursts for the HADAR Project

Zhang,

Chen,

Feng

et al. 2024

ApJ

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The High Altitude Detection of Astronomical Radiation (HADAR) is a novel wide-field Cherenkov Telescope. It is designed for gamma-ray astronomy in the energy range of 10 GeV to 100 TeV, with gamma-ray bursts (GRBs) being one of its primary research focuses. To assess its complementary capabilities, this study first presents the Crab sensitivity of HADAR. Then, to compare the sensitivity of GRBs, the observation time for all experiments is standardized to 100 s. To clearly demonstrate HADAR’s advantages, we estimate its observational results with a 221009A-like GRB. The study found that HADAR is capable of more comprehensively recording the bending and absorption of self-Compton radiation, which is expected to fill observational gaps in space- and ground-based experiments. We anticipate that this facility will ensure a large statistical GRB sample and advance our understanding of GRBs.

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“…In order to improve the measurement of signals in the presence of night sky background noise, Xin GG et al proposed a triggering algorithm suitable for HADAR. For more details on the triggering process, refer to [14], where the PMT trigger setting of this study aligns with theirs.…”

Section: Hadar Simulation Settingsmentioning

confidence: 99%

Research on the Gamma/Proton Identification Effect of HADAR Based on Multi-Layer Sensor

2024

mpcr

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This study aims to optimize the discrimination performance of gamma/proton in high altitude detection of astrological radiation (HADAR) experiments by employing the multilayer perceptron (MLP) algorithm. The HADAR experiment is used to observe the Cherenkov light produced by cosmic rays and gamma rays in the atmosphere via a composite array composed of four water lenses and surrounding scintillation detectors. And it is highly competitive in detecting the transient sources and the prompt emission of gamma-ray bursts due to its advantages such as low threshold energy (~30GeV) and wide field of view (~30°). However, the image discrimination between background noise and signal become weak when the detected energy of HADAR is less than 100 GeV, leading to unsatisfactory gamma/proton discrimination performance of traditional Hillas parameter methods. In this study, we employ MLP as a discriminator to conduct training and classification based on input characteristic parameters (such as Hillas parameters and core information). The results of Monte Carlo simulation demonstrate that the MLP method exhibits excellent performance and accuracy gamma/proton identification. Specifically, the discrimination between signal and background noise is enhanced at detection energies between 30-100 GeV, and the highest achieved Q-factor is 2.17 (proton exclusion rate ~97.80%, gamma retention rate ~32.20%). This study provides valuable references and a solid foundation for enhancing the gamma/proton discrimination performance of HADAR.

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A novel trigger algorithm for wide-field-of-view imaging atmospheric Cherenkov technique experiments

Cited by 5 publications

References 29 publications

Gamma/Hadron Separation Method for the HADAR Experiment

Gamma/Hadron Separation Method for the HADAR Experiment

Study of the Observation Sensitivity of Gamma-Ray Bursts for the HADAR Project

Research on the Gamma/Proton Identification Effect of HADAR Based on Multi-Layer Sensor

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