An apparatus to measure water optical attenuation length for LHAASO-MD

Liu, Cong; Xiao, Gang; Feng, S. H.; Wang, Lingyu; Li, Xiurong; Zuo, Xin; Cheng, Ning; Wang, Hui; Gao, Bo; Duan, Zhihao; Liu, Jia; He, H. H.; Saeed, Mohsin Hassan

doi:10.1016/j.nima.2018.03.029

Cited by 8 publications

(5 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second is the indirect measurement method, that is, through the amount associated with the attenuation length to invert the value of the water attenuation length. Although the direct measurement method is straightforward, the signal attenuation of light in water is very small, and the experiment requires effective detection of small signals and control of errors within a very small range, which is difficult to achieve for the measurement [6]. The integrating cavity technique is, however, considerably simpler to implement.…”

Section: Methodsmentioning

confidence: 99%

Automatic detection device for the attenuation length of water measured by reffection cavity

Zhu¹,

Tang²,

Zhang³

et al. 2023

Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)

View full text Add to dashboard Cite

Water serves as a key medium for the water Cherenkov detector, and the water absorption length significantly affects the efficiency of the detectors. The water absorption length represents the distance traveled by 1/e of light intensity attenuation due to the absorption of photons in water, representing the cleanliness of the water. It is a great challenge to measure or monitor the water attenuation length accurately at home and abroad. A method, like the integrating cavity ring-down spectroscopy is described in this paper, which could reveal the water absorption length and the reflectivity of the material at the same time. Based on it, an automatic detection device was designed and installed. A cylindrical cavity covered with highly reflective materials on the inner wall was employed to load the water. A cover is designed which can be controlled by a stepper motor to change the depth of water in the reflective chamber by moving the position of the cover, and at the same time sealing the reflective chamber by using the variable air pressure of the tires. The light provided by a pulse-twinkled LED was injected into the cavity, and the data was recorded by a fast photomultiplier tube(PMT). Finally, the collected waveforms of PMT at different water depths of the cavity were analyzed to get the absorption length of water and the reflectivity of the inner wall.

show abstract

Section: Methodsmentioning

confidence: 99%

Automatic detection device for the attenuation length of water measured by reffection cavity

Zhu¹,

Tang²,

Zhang³

et al. 2023

Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)

View full text Add to dashboard Cite

show abstract

“…This water absorption length is reasonable when compared with the numbers mea-sured for the current detector arrays. A study from the LHAASO collaboration using a custom developed apparatus reports attenuation lengths around 16.8 m at 405 nm Li et al [23]. Studies performed by the HAWC collaboration shows attenuation lengths varying between 5 m and 16 m for 405 nm Abeysekara and et al [24].…”

Section: Overview Of Simulation Toolsmentioning

confidence: 99%

Optimization Studies of a Water Cherenkov Detector for Gamma-ray Astronomy

Kunwar

Schoorlemmer

Hinton

2019

Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019)

View full text Add to dashboard Cite

Ground-based, wide field of view instrumentation in gamma-ray astronomy is currently limited to the northern hemisphere and hence, lacks sensitivity to our Galactic Center and the rest of the southern sky. A Southern Gamma Observatory comprising an array of ground-level detector units with a high fill factor (> 70 %) at high altitude (> 4 km) could be used to observe the southern sky. Water Cherenkov Detectors (WCDs) have shown their potential as detector units for such an array. Detailed simulations are needed to understand the response of WCDs to the flux of secondary particles impinging on them. In this contribution, we study the complete simulation chain from the air shower simulation with CORSIKA to the detector level simulation with GEANT4, in an attempt to optimize WCDs.

show abstract

“…The seawater pH is set to be the estimated value at the Archean-Proterozoic boundary, 7 (Krissansen-Totton et al, 2018). In consideration of the low productivity in the Precambrian ocean, the seawater light attenuation length scale is set to 15 m, which is close to pure water (Kim, Pradal, & Gnanadesikan, 2015;Li et al, 2018).…”

Section: Model Parameterizationmentioning

confidence: 99%

Photoferrotrophy, BIF deposition, and iron-free oxygen oases in the Archean surface ocean

Crowe,

Ding,

Zhao

2023

Preprint

View full text Add to dashboard Cite

Banded Iron Formations (BIFs) are both the world’s largest ore deposits and important geological archives that record the early evolution of the Earth-Life system. BIFs were likely deposited as the result of ferrous iron [Fe(II)] oxidation, precipitation, and sedimentation from iron-rich (ferruginous) seawater, mostly during the Archean Eon. Proposed mechanisms for iron oxidation include abiotic reactions with photosynthetic oxygen, reaction with oxygen catalyzed by iron-oxidizing bacteria (IOB), and anoxic oxidation by anoxygenic iron-oxidizing phototrophic bacteria (photoferrotrophs). These iron oxidation processes may have operated concurrently, but their relative contributions to BIF deposition have not been considered. Here, we developed a 1-D ferruginous ocean model incorporating abiotic iron cycling and the physiology of oxygenic phototrophs, microaerophilic IOB, photoferrotrophs, and iron-reducing bacteria. Our model shows that, under Archean ocean conditions, most iron oxidation and precipitation would have been driven by photoferrotrophy, with a small fraction by microaerophilic IOB and a negligible contribution from abiotic reactions. The combined activities of these pathways led to BIF deposition at rates in line with geological records and, importantly, allowed the development of an Fe(II)-free surface ocean conducive to the formation of oxygen oases and the proliferation of oxygenic phototrophs. Teaser Archean ocean simulation shows that photoferrotrophs dominated the precipitation of BIFs and promoted the formation of marine oxygen oases.

show abstract

An apparatus to measure water optical attenuation length for LHAASO-MD

Cited by 8 publications

References 5 publications

Automatic detection device for the attenuation length of water measured by reffection cavity

Automatic detection device for the attenuation length of water measured by reffection cavity

Optimization Studies of a Water Cherenkov Detector for Gamma-ray Astronomy

Photoferrotrophy, BIF deposition, and iron-free oxygen oases in the Archean surface ocean

Contact Info

Product

Resources

About