CT machine. It is shaped like a drum washing machine . The patient lies inside, and the X-rays emitted by the machine are used to examine the body tissue, and finally form an image, which is convenient for doctors to determine the cause of the disease.
Do you know? Our country has built a super scientific device in Dongguan, which is similar to a CT machine - the spallation neutron source.
It is a "super microscope" that can "see everything as large as aircraft wings and high-speed railway wheels and rails, as small as lithium batteries and DNA molecules , as close as shampoo and toothpaste, and as far away as superconducting materials in space... to "the structure and changes of these substances. So, how does this big scientific device work? In what areas can it play a role?
1. The principle of spallation neutron source
To understand what a "sparse neutron source" is, we must first understand what "sparse" is? What is " neutron source "?
neutron - We have learned in middle school physics that it is part of the nucleus and is an uncharged nucleon . It is not easily hindered by other charged protons or electrons. is therefore very penetrating and destructive. Low.
A neutron source is a device that can generate free neutrons. It is divided into many types due to different ways of generating neutrons, and the spallation neutron source is one of them.
Free neutrons decay easily and have extremely short life spans. To produce a large number of free neutrons in a short period of time, must use protons to hit the nucleus and bombard the neutrons out. This process is called spallation. Just like when we throw a ping pong ball into a box full of ping pong balls, some ping pong balls will jump up, and some will jump out of the box upon impact, which is very similar to the process of falling apart.
The spallation neutron source uses high-energy proton beams to bombard heavy element targets and separate a large number of neutrons from the target.
It is not a simple machine, but a giant equipment covering an area of thousands of acres. includes various high-precision equipment and instruments as well as supporting facilities, civil engineering , etc., and is a comprehensive and organic whole.
According to statistics, in order to build this super device, my country went through more than 10 years of preparation, took six and a half years to build, and spent about 2.3 billion yuan before finally completing the main work in 2018. Although costs a lot, it is still a neutron-generating device with low cost, high safety and great advantages compared with other nuclear reaction neutron sources.
2. Application fields of spallation neutron sources
Before the establishment of the spallation neutron source in my country, only three countries in the world, the United States, the United Kingdom and Japan, had spallation neutron source devices.
Because installations are rare, use in various countries requires payment, application, and queueing. The process is cumbersome and time-consuming. Sometimes it takes several months to wait, seriously delaying the experimental results. The completion of the
spallation neutron source marks that our country has broken the monopoly of the United States, Britain and Japan. It also shows that our country has entered the world's advanced ranks in the research and application of neutron scattering technology.
At present, spallation neutron sources can play an important role in research in many fields such as chemistry, magnetics, superconductivity, medicine, crystalline materials, polymers, complex fluids, and engineering.
For example, in the field of materials, the lithium batteries used in our mobile phones need to take into account characteristics such as battery life, capacity and safety when designing. This involves many microscopic processes and is not easy to detect and test.
At this point, the spallation neutron source can come in handy.
The neutron beam it emits can easily penetrate the battery material. When the battery is charged and discharged, the real-time working status of the electrode, electrolyte and interface is analyzed through the neutron scattering data. This allows scientific researchers to understand the working mechanism of the battery. Take effective measures to improve battery performance.
In terms of medicine, the Spallation Neutron Source assisted Dongguan People's Hospital in building the world's leading cancer treatment experimental center - the Boron Neutron Capture Therapy Center.
To put it simply, a boron-containing drug is injected into the patient's body. After the drug enters the cancer cells, it is irradiated with neutron rays. This ray can react with the boron entering the cancer cells, killing the cancer. cells, but no damage to other surrounding tissues.
There is also the aviation field that our country has always attached great importance to. A large number of electronic components are used in aviation engineering. These electronic components have high precision, high standards, and high requirements.
These device materials are prone to nuclear reactions with atmospheric neutrons, causing single particle effects and causing system operation errors. Once the system is damaged and causes an aviation disaster, the loss will be immeasurable. Therefore, it is very important to improve the resistance of electronic devices to neutron single event effects.
In this case, experiments can only be carried out using neutron sources. The spallation neutron source is the most ideal simulation source of all neutron sources. With the assistance of the spallation neutron source, our country has a guarantee in improving the reliability and safety of electronic components , and can better develop aviation technology.
Summary
The spallation neutron source is a powerful tool for exploration. It can emit light and heat as small as to understand the microscopic world or as large as to explore the vast universe. At present, my country's spallation neutron source is open to global users and operates stably and efficiently. It not only promotes the development of my country's science and technology, industry and other technologies, but also contributes to the innovation and progress of science and technology around the world.
