At present, there are about 20 experimental projects in the world that are or will soon start to detect dark matter, and it is expected that dark matter particles can be detected within 4 to 5 years. By detecting the secondary particles produced by the annihilation of dark matter, such as neutrinos, positive and negative electron pairs, protons, antiprotons, etc., is an effective way to understand dark matter, and tellurium dioxide crystals are the first choice for detecting neutrinos. The CUORE project uses tellurium dioxide crystals as radiant calorimeters to detect the absolute mass and properties of neutrinos.
The patent uses a secondary crystal growth preparation method to obtain high-purity tellurium dioxide single crystal, especially the content of radioactive impurities such as U and Th can be reduced to 10-13g / g, thus making Shanghai Silicate a large neutrino detection project (CUORE project) The world's only supplier of core detection materials.
In the field of nuclear physics, neutrino experiments have always been the scientific frontiers of world attention. However, what is the mass of the neutrino (static) and how is it converted between different types of neutrinos? It is still a basic scientific problem to be solved.
At present, the measurement of absolute neutrinos from double β decay provides the only experimental method. Tellurium dioxide (TeO2) crystal is not only an acousto-optic crystal with a high quality factor, but also a crystal for neutrino detection with double β decay characteristics. Since the natural abundance of 130Te is 33.8%, there is no need to concentrate it, and the cost is low, so TeO2 crystal has become the first choice for double β decay source.
The neutrino detection frontier scientific project CUORE (Cryogenic Underground Observatory for Rare Events), a rare physical phenomenon observed at low temperature by the cooperation of scientists from many countries, is the use of 998 TeO2 single crystal arrays to detect the absolute mass and nature of neutrinos, in order to unlock the scientific community The important dark matter mystery. The TeO2 crystal as a double β decay source requires large size (not less than 50mm × 50mm × 50mm), high purity (unintentionally doped impurity concentration less than 10-7g / g, radioactive impurities such as U, Th, etc. Less than 10-13g / g).
At present, the Tellurium Oxide Group of Shanghai Silicate Institute Pilot Base has provided more than 1,000 pieces of high-purity tellurium dioxide single crystals to the CUORE project, achieving foreign exchange earning of more than 5 million US dollars. High-purity tellurium dioxide single crystal, as a large-size high-quality tellurium dioxide single crystal new product, has received financial support from Shanghai and the National Key New Product Program in 2010 and 2011, and has achieved good social and economic benefits.
This internationally leading scientific research achievement not only helps enhance China's international influence in the field of dark matter detection, but also plays a positive role in promoting neutrino detection and dark matter detection in China.
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