Speaker
Description
The high-pressure Xe TPC is a crucial detector technology used in the searching for neutrino-less double beta decays (NLDBD). The PandaX-Ⅲ experiment, located at the China Jinping Underground Laboratory II (CJPL-II), currently employs a 10 bar, 140 kg TPC filled with 90% enriched 136Xe gas to investigate NLDBD. The readout plane of the TPC is comprised of 52 thermal-bonding Micromegas detectors, each measuring 200×200 mm².
Significant improvement has been made in the research on thermal-bonding Micromegas used in PandaX-III. It is the first large-area gaseous detector operating in high-pressure gas, thereby greatly extending the working environment of gaseous detectors. The resistive Ge layer and polishing PCB contributes to higher gain and improved stability. The use of flexible PCBs and other low-radioactivity materials aids in maintaining a low radiopurity background. A fabrication process optimized for mass production of the Micromegas was developed, and more than 52 micromegas detectors had been produced. Testing of the prototype yielded impressive results, demonstrating an energy resolution of 20% at 5.9 keV and a high gain of up to 10^4 in 10 bar Ar/Iso (97.5/2.5). Currently, the detector assembly was completed and calibration using cosmic muons in 1 bar Ar/Iso(97.5/2.5) has been processed. Additionally, an improved version of the thermal-bonding Micromegas, characterized by lower radioactivity and better stability has been developed for future upgradation.
| Primary experiment | PandaX-III experiment |
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