STORY: World's deepest underground lab to boost China's research in dark matter
SHOOTING TIME: Dec. 7, 2023
DATELINE: Dec. 8, 2023
LENGTH: 00:02:14
LOCATION: CHENGDU, China
CATEGORY: TECHNOLOGY

SHOTLIST:
1. various of the laboratory
2. various of Jinping Mountain
3. SOUNDBITE 1 (Chinese): LI HONGBI, Engineer with the physics laboratory
4. SOUNDBITE 2 (Chinese): LI HONGBI, Engineer with the physics laboratory
5. SOUNDBITE 3 (Chinese): YUE QIAN, Professor at Tsinghua University

STORYLINE:

A 2,400-meter-deep physics laboratory in southwest China's Sichuan Province became operational on Thursday, making it the deepest and largest underground lab in the world.

The Deep Underground and Ultra-low Radiation Background Facility for Frontier Physics Experiments (DURF) is located beneath Jinping Mountain in Sichuan's Liangshan Yi Autonomous Prefecture.

The DURF, with a total room capacity of 330,000 cubic meters, is the second phase of China Jinping Underground Laboratory. It started construction in December 2020 and was jointly built by Tsinghua University and Yalong River Hydropower Development Company, Ltd.

SOUNDBITE 1 (Chinese): LI HONGBI, Engineer with the physics laboratory
"The second phase of China Jinping Underground Laboratory started construction on Dec. 20, 2020, and after about three years of construction, it has finally been completed. Currently, the laboratory's air, water, and electrical systems have all been completed and put into operation, meeting the conditions for the entry of the research personnel. Starting today (Thursday), all our research groups can focus on the scientific experiments in the newly-built facility."

Scientists believe the laboratory provides a "clean" space for them to pursue the invisible substance known as dark matter. They said the extreme depth helps block most cosmic rays that mess with the observation.

SOUNDBITE 2 (Chinese): LI HONGBI, Engineer with the physics laboratory
"The DURF is exposed to a flux of cosmic rays which is only one hundred-millionth of that on the earth's surface, allowing scientists to conduct experiments effectively. But radon is released by bedrock. So we have to contain radon within an extremely low concentration through waterproof measures and keep it outside the laboratory."

SOUNDBITE 3 (Chinese): YUE QIAN, Professor at Tsinghua University
"Building a large-scale scientific facility to conduct the most significant cutting-edge research allows us to face major international scientific frontier questions and might produce major results. 
I believe that for researchers, such excellent experimental conditions enable us to pursue our dreams and explore the mysteries of the universe in the world's deepest laboratory."

Xinhua News Agency correspondents reporting from Chengdu, China.
(XHTV)