Welcome important progress!, The world's deepest underground laboratory
On August 31st, the reporter learned that the world's largest polyethylene shielding chamber has been built in the second phase of the Jinping underground laboratory project, and the laboratory chamber has entered the clean laboratory construction phase.
The Jinping Underground Laboratory is the first dark matter laboratory in China and also the deepest, largest, and best equipped underground laboratory in the world. Its location is within the Jinping Mountain Tunnel, which is 2400 meters underground in Liangshan Prefecture, Sichuan Province. This site selection can utilize the thick rock layers of the mountain to block the interference of cosmic rays, creating a unique environment for laboratory construction.
The waterproofing and radon suppression construction of the project tunnel wall has been completed. Respondents provide pictures
In order to serve high-level cutting-edge physics experiments and ensure the accuracy of laboratory construction, the project construction party adopts key technologies such as waterproofing and radon suppression, and strictly selects low background construction materials, striving to reduce the impact on the original extremely low radiation environment of the cave. "In the construction of underground laboratories, we found that these engineering measures are far from enough, and a series of extremely deep underground extremely low radiation background shielding devices are needed to achieve lower radiation background requirements. To this end, we have built a large combined solid shielding device - a polyethylene shielding chamber." said Tan Lei, Chief Engineer of the Jinping Large Facilities II Project of China Construction Third Engineering Bureau.
Tan Lei introduced that the polyethylene shielding cabin is 51.9 meters long, 9.78 meters wide, and 7.9 meters high, with a thickness of 1 meter. It is mainly composed of high-density polyethylene sheets with a thickness of 100 millimeters and non adhesive paving, weighing over 1800 tons.
The polyethylene shielded cabin project is under construction. Respondents provide pictures
It is understood that the requirements for the background radiation value index of the cabin building materials are high, which is a major challenge in the early construction work. "Building the cabin is to better shield radiation, but the materials used to build the cabin inherently contain radiation." Wang Wei, the project manager of the construction party, said, "The construction of polyethylene shielding cabins is a key link in ensuring the construction of the most 'pure' laboratory. We have screened more than 60 suppliers to provide support for the construction of shielding cabins."