Study on the performance of electromagnetic particle detectors of LHAASO-KM2A

Zhang, Zhongquan; Hou, Chao; Cao, Z.; Chang, Jingfan; Feng, Cunfeng; Erlan, Hanapia; Gong, G.; Liu, Jia; Lv, Hongkui; Sheng, X. D.; Zhang, Shaoru; Chengguang, Zhu

doi:10.1016/j.nima.2016.04.079

Cited by 19 publications

(14 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6) consists of 4 plastic scintillation tiles (100 cm × 25 cm × 1 cm each) covered by 5-mm-thick lead plates to absorb low-energy charged particles in showers and to convert shower gammas into electron-positron pairs. Sixteen wavelength-shifting fibers (2.7 m in length and 1.5 mm in diameter) are embedded in 32 grooves (each 1.8 mm in depth and 1.6 mm in width) of each tile to collect scintillation light generated by charged particles and guide the scintillation light to a 1.5-inch photomultiplier tube (PMT) with a temperature coefficient < 0.2%/ • C. Each PMT is supplied by a high-voltage module with a temperature coefficient of < 0.01%/ • C, while the high voltage of each PMT can be adjusted independently [9,10].…”

Section: Km2a-edmentioning

confidence: 99%

Design of the LHAASO detectors

2018

Radiat Detect Technol Methods

View full text Add to dashboard Cite

Introduction The Large High Altitude Air Shower Observatory plans to build a hybrid extensive air shower array with an area of about 1 km 2 at an altitude of 4,410 m a.s.l. in Sichuan province, China, to explore the origin of high-energy cosmic rays. KM2A LHAASO-KM2A will detect gamma ray sources with a sensitivity of about 1% Crab Unit at 100 TeV. It covers an area of 1 km 2 with a total of 5195 scintillation detectors. Its angular resolution reaches about 0.3 degrees, and the energy resolution is better than 25%. With the help of 1171 muon detectors, cosmic nuclei background will be rejected to a level of 10-4 at 50 TeV. The design and performances of the scintillation detectors and muon detectors are described in detail. WCDA LHAASO-WCDA focuses on surveying the northern sky for steady and transient sources from 100 GeV to 20 TeV, with a very high background rejection power and a good angular resolution. The WCDA consists of three water ponds with a total area of 78,000 m 2 , and the effective water depth is 4 m. Each water pond is divided into 5m × 5m cells partitioned by black plastic curtains to prevent penetration of the light from neighboring cells. An 8-inch PMT sits at the bottom center of each cell, looking upward to collect Cherenkov light generated by shower secondary particles in water. WFCTA LHAASO-WFCTA is composed of 12 wide-field-of-view Cherenkov/fluorescence telescopes. Each telescope consists of a spherical light collector of about 4.7 m 2 and focal plane camera of 32 × 32 pixels with a pixel size of 0.5 degree. LHAASO prototype arrays A prototype array about 1% of LHAASO has been constructed at Yangbajing Cosmic Ray Observatory and has been in operation for more than 2 years. Its performance fully meets the design requirements. Conclusion The LHAASO detectors are designed to fulfill the physical goals in gamma ray astronomy and cosmic ray physics. One-fourth of LHAASO will be constructed and put into operation to produce physical data by the end of 2018. The whole array will be finished in the beginning of 2021.

show abstract

Section: Km2a-edmentioning

confidence: 99%

Design of the LHAASO detectors

2018

Radiat Detect Technol Methods

View full text Add to dashboard Cite

show abstract

“…The ED consists of four plastic scintillation tiles of 100 cm × 25 cm × 2.5 cm each. The scintillation photons are detected by a 1.5 inch photomultiplier tube (PMT) through 2.7 m wavelength-shifting fibers embedded in the grooves in the scintillation tiles [5]. For each PMT, two output channels (anode and dynode outputs) with different gains and linearity performances are deployed to cover the large dynamic range [6].…”

Section: Lhaaso-km2a Electromagnetic Particle Detectorsmentioning

confidence: 99%

“…Timing calibration of the LHAASO-KM2A electromagnetic particle detectors Hongkui Lv 5. A Gaussian function is fitted to the hit time residual distribution, the peak value of which is considered as the time correction to be applied to the hit times for a new iteration.…”

Section: Pos(icrc2017)455mentioning

confidence: 99%

Timing calibration of the LHAASO-KM2A electromagnetic particle detectors

Lv¹,

He²,

Sheng³

et al. 2017

Proceedings of 35th International Cosmic Ray Conference — PoS(ICRC2017)

Self Cite

View full text Add to dashboard Cite

The Large High Altitude Air Shower Observatory (LHAASO) is a multipurpose project focusing on high energy gamma-ray astronomy and cosmic ray physics. The 1 km 2 array (KM2A) of this observatory will consist of 5242 electromagnetic particle detectors (EDs) and 1171 muon detectors (MDs). The remoteness and numerous EDs extremely demand a robust and automatic calibration procedure. In this paper, a self-calibration method which relies on the measurement of charged particles within the extensive air showers is proposed. The method is fully validated by Monte Carlo simulation and successfully applied in a KM2A prototype array experiment. The self-calibration method can be used to determine the detector time-offset constants at the subnanosecond level, which is adequate to meet the physical requirements of LHAASO experiment.

show abstract

“…The resulting performances of ED fully meet the design requirements. More details about the ED and its performances can be found elsewhere [4,5]. According to the engineer array result, the noise rate is 2 kHz for each ED.…”

Section: The Km2a Detector and Simulation 21 The Km2a Detectormentioning

confidence: 99%