Test bench for fibers of the LHAASO-WCDA time calibration system

Liu, J.Y.; Gao, Puze; Yu, C. X.; Chen, M.J.; Luo, Y.A.; Yao, Zhiguo; Zha, M.; Wu, Huan; Li, H.C.; Wang, X.J.

doi:10.1088/1748-0221/12/10/p10021

Cited by 8 publications

(9 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…30). Each WCD is equipped by an 8-inch PMT for timing and pulse height in low range and a 1.5-inch PMT for pulse height in high range at the center of WCD and 4 m beneath water surface [16]. The pool measures EAS directions with angular resolution better than at 10 TeV and at 600 GeV.…”

Section: Wcdamentioning

confidence: 99%

Chapter 1 LHAASO Instruments and Detector technology *

Cao

et al. 2022

Chinese Phys. C

View full text Add to dashboard Cite

The Large High Altitude Air Shower Observatory ( LHAASO ) ( Fig. 1 ) is located at Mt. Haizi (4410 m a.s.l., 600 g/cm2, 29◦ 21’ 27.56” N, 100◦ 08’ 19.66” E) in Daocheng, Sichuan province, P.R. China. LHAASO consists of 1.3 km2 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 m2, 18 wide field-of-view air Cherenkov telescopes (WFCTA ) and a newly proposed electron-neutron detector array ( ENDA ) covering 10,000 m2. Each detector is synchronized with all the other through a clock synchronization network based on the White Rabbit protocol. The observatory includes an IT center which comprises the data acquisition system and trigger system, the data analysis facility. In the following of this Chapter, all the above mentioned components of LHAASO will be briefly described, together with infrastructure which is a fundamental component of the LHAASO observatory.

show abstract

Section: Wcdamentioning

confidence: 99%

Chapter 1 LHAASO Instruments and Detector technology *

Cao

et al. 2022

Chinese Phys. C

View full text Add to dashboard Cite

show abstract

“…Since the plastic fibers have cropping errors in the production process with an error of several cms, the relative time offsets among the fibers in the bundle need to be calibrated after the LED and the fiber bundle assembly. For this purpose, a test platform based on high-precision TDC, onedimensional electric slide and fast PMT for relative time offsets of fibers is built [2]. After the test, the time accuracy of optical fiber in calibration system is 10 𝑝𝑠, which can meet the requirements of calibration accuracy.…”

Section: Pos(icrc2021)751mentioning

confidence: 99%

Time calibration of the LHAASO-WCDA detectors

Gao¹,

Liu²,

Zhang³

et al. 2022

Proceedings of 37th International Cosmic Ray Conference — PoS(ICRC2021)

View full text Add to dashboard Cite

The LHAASO (Large High Altitude Air Shower Observatory) is a multi-purpose experiment for measuring the high energy gamma rays and cosmic rays. One of the major detectors is the 78,000 𝑚 2 WCDA (Water Cherenkov Detector Array), equipped with 3120 PMTs, which aims to survey the gamma-ray sky continuously in a wide energy range, from 100 GeV to 30 TeV. Precisely calibrating the time offsets of each detector cell is essential to obtain a good angular resolution for observing the gamma ray sources[1]. A dedicated system composed of LED light sources and fibers guided lights to every cell is used for time offset calibration of the whole array. Besides, Cosmic-ray shower events are analyzied for caliculating the time offsets and the charge-time correlations. Finally the observation to the Crab Nebula is visited to fix the pointing error brought by above calibration and calculations. Above calibration procedure and the final calibration results are presented in this talk.

show abstract

“…The White Rabbit Protocol (WR) [2] is used to distribute the clock and ensure the synchronization of each detector unit within 200 ps through a fiber network over the entire LHAASO array. In the central timing station, a rubidium oscillator synchronized with GPS/BeiDou Time (BDT) is used as the source of the clock, which is distributed to the entire array through the WR network.…”

Section: Wcda-1 Detector Arraymentioning

confidence: 99%

Performance of LHAASO-WCDA and observation of the Crab Nebula as a standard candle *

Aharonian¹,

An²,

Bai³

et al. 2021

Chinese Phys. C

Self Cite

View full text Add to dashboard Cite

The first Water Cherenkov detector of the LHAASO experiment (WCDA-1) has been operating since April 2019. The data for the first year have been analyzed to test its performance by observing the Crab Nebula as a standard candle. The WCDA-1 achieves a sensitivity of 65 mCU per year, with a statistical threshold of 5 . To accomplish this, a 97.7% cosmic-ray background rejection rate around 1 TeV and 99.8% around 6 TeV with an approximate photon acceptance of 50% is achieved after applying an algorithm to separate gamma-induced showers. The angular resolution is measured using the Crab Nebula as a point source to be approximately 0.45° at 1 TeV and better than 0.2° above 6 TeV, with a pointing accuracy better than 0.05°. These values all match the design specifications. The energy resolution is found to be 33% for gamma rays around 6 TeV. The spectral energy distribution of the Crab Nebula in the range from 500 GeV to 15.8 TeV is measured and found to be in agreement with the results from other TeV gamma ray observatories.

show abstract

Test bench for fibers of the LHAASO-WCDA time calibration system

Cited by 8 publications

References 9 publications

Chapter 1 LHAASO Instruments and Detector technology *

Chapter 1 LHAASO Instruments and Detector technology *

Time calibration of the LHAASO-WCDA detectors

Performance of LHAASO-WCDA and observation of the Crab Nebula as a standard candle *

Contact Info

Product

Resources

About