|
 Daya
Bay, China ¨C On October 13, 2007, members of the Daya Bay Collaboration
and government officials from China and the U.S. Department of Energy
held a groundbreaking ceremony for the international Daya Bay Reactor
Neutrino experiment at the Daya Bay Nuclear Power Facility, which is
located in Shenzhen, Guangdong Province, about 55 kilometers northeast
of Hong Kong in Southern China. The experiment is poised to discover a
new kind of neutrino "oscillation," an outstanding mystery concerning
the behavior of the subatomic particles known as neutrinos.
¡®I believe the Daya Bay Reactor Neutrino Experiment will achieve a full
success with the efforts and wisdom of the scientists¡¡¯ remarked by
Jinpei Cheng, Vice Minister of Ministry of Science and Technology, in
the ceremony.
Neutrinos (and their antiparticles) come in three kinds, and in recent
years several experiments have determined that the three types can
morph, or oscillate, among themselves. Oscillation has a profound
consequence, namely that neutrinos, once thought to be massless, do
indeed have a tiny mass; neutrinos fill the Universe, and their effect
on the evolution and structure of the Universe is therefore significant.
Learning more about this new kind of neutrino oscillation may also help
scientists unlock the secret of why antimatter is largely missing from
the Universe, which makes our existence possible.
Robin Staffin, Director of the Office of High Energy Physics of U.S.
Department of Energy, said, ¡¯At the ground where we are now stand,
scientists will measure with the world¡¯s greatest precision, one of the
most important parameters of nature.¡¯
The ceremony on October 13 marks the beginning of civil construction
near the Daya Bay and Ling Ao nuclear power plants, the sources of the
antineutrinos to be measured in the experiment. Three experimental halls
connected by long tunnels will be excavated in the adjacent mountains,
which will shield the experiment from cosmic rays. Each hall will
feature a 10-meter deep pool of water, within which the antineutrino
detectors (eight in all) will be deployed. The water protects the
detectors from radiation that could interfere with measurements and also
helps identify any unwanted particles.
Yifang Wang of the Institute of High Energy Physics, co-spokesperson of
the Daya Bay Experiment, commented that ¡®The project is now progressing
well¡We are now ready for manufacturing and mass production of the
equipment.¡¯ The first experimental hall is scheduled to be ready by the
end of 2008. Commissioning of the detectors in this hall will take place
in 2009. Construction will continue and is anticipated to last about two
years, with installation of the last detector scheduled for 2010. ¡®The
completed experiment will be the best in the world for investigating
this new, unknown kind of neutrino oscillation using nuclear reactors,¡¯
Kam-Biu Luk of the University of California at Berkeley, co-spokesperson
of the experiment, said.
Chunli Bai, Executive Vice President of the Chinese Academy of Sciences,
said, ¡®The Daya Bay Reactor Neutrino Experiment bears great importance
in strengthening international collaboration in the field of basic
science.¡¯
The Daya Bay Collaboration is made up of thirty-five institutions with a
total of over 190 collaborators from three continents, working together
to build the experiment. The project is supported by the Ministry of
Science and Technology of China, the Chinese Academy of Sciences, the
National Natural Science Foundation of China, the Guangdong Provincial
Government, the Shenzhen Municipal Government, the China Guangdong
Nuclear Power Group, and the Office of High Energy Physics of the U.S.
Department of Energy. Additional funding is being provided by the U.S.
National Science Foundation, other countries and regions including Hong
Kong, Taiwan, the Czech Republic, and Russia. The Daya Bay Reactor
Neutrino Experiment is one of the largest cooperative scientific
projects between China and the U.S., and is establishing a model for
future cooperation in the realm of scientific research. |
