How do neutrino detectors: an example of Japanese “Super-Kamiokande”

Hiding at the depth of 1 km under the mountain, Ikeno, in a zinc mine Kamioka, 290 km North from Tokyo (Japan) is the place as its lair would dream of any super villain from some movie or story about supercoach. Here is a “Super-Kamiokande” (or “Super-K”) neutrino detector. Neutrinos are a subatomic fundamental particles, very weakly interacting with ordinary matter. They are able to penetrate completely into all and everywhere. The observation of these fundamental particles helps scientists to find the collapsing star and learn new information about our Universe. Business Insider spoke with three staff “Super-Kamiokande” and found out how it all works and what experiments performed by scientists.

Immersed in the subatomic world

Neutrinos very difficult to detect. So difficult that the famous American astrophysicist and science popularizer Neil Degrasse Tyson once called “the most elusive prey in space.”

“Matter is not for neutrinos no obstacles. These subatomic particles can pass through a hundred light-years metal and not even slow down,” said Degrasse Tyson.

But why scientists are trying to grasp?

“When the supernova occurs, the star collapses into itself and becomes a black hole. If this event happens in our galaxy, the neutrino detectors like the same “Super-K” is able to capture emitted in this process, neutrinos. Such detectors are very few in the world,” explains Yoshi Uchida, Imperial College London.

Before a star collapses, it emits in all directions of outer space neutrinos, and the laboratory of such a “Super-Kamiokande” serve in the role of early warning systems that tell scientists where to look to see the last moments of the lives of stars.

“Simplified calculations say that the events of a supernova explosion in the radius in which our detectors can catch only happen once in 30 years. In other words, if you miss one, you’ll have to wait on average a few decades to the next event,” says Uchida.

Neutrino detector “Super-K” not just detects neutrinos falling on him from outer space. In addition, it is transmitted neutrinos with the T2K experimental setup, located in the town of Tokaj, in the opposite part of Japan. Sent to the neutrino beam has to go about 295 miles, after which it enters the detector “Super-Kamiokande”, located in the Western part of the country.

The observation of how neutrinos change (or oscillate) when moving through matter, can tell scientists more about the nature of the Universe, for example, about the relationship between matter and antimatter.

“Our model the “Big Bang” suggests that matter and antimatter were created in equal proportions,” — said in an interview with Business Insider, Morgan Vasko from Imperial College London.

“However, the bulk of antimatter for some or for some reason disappeared. Ordinary matter is much more than antimatter.”

Scientists believe that the study of neutrinos may be one of the ways through which the answer to this riddle is finally found.

As a “Super-Kamiokande” catches neutrinos

Located at a depth of 1000 meters under the ground, “Super-Kamiokande” size of a 15-storey building represents something.

The scheme of a neutrino detector “Super-Kamiokande”

A huge stainless steel tank in the form of a cylinder filled with 50 thousand tons of specially purified water. Passing through this water, the neutrino moves at the speed of light.

“Neutrinos entering the tank produce light scheme is the same as Concorde had broken the sound barrier,” says Uchida.

“If the plane moves very fast and breaks the sound barrier, behind it creates a very powerful shock wave of sound. Similarly, a neutrino passing through the water and moving faster than the speed of light creates a light Shockwave,” explains the scientist.

On the walls, the ceiling and the bottom of the tank is installed a little more than 11 000 special gold-colored “light bulbs”. They are called photomultipliers are very sensitive to light. They catch the light, these shock waves are generated by neutrinos.

Look photomultipliers so

Morgan Vasco describes them as “back bulbs”. These devices are so sensitive that even with a single quantum of light is able to generate an electrical impulse, which is then processed by a special electronic system.

Don’t drink the water, dude

So the light from shock waves created by neutrinos made up of sensors the water in the tank should be crystal clear. So clean that you can’t even imagine. “Super-Kamiokande” it is a constant process of special multi-level cleaning. Scientists irradiate it with ultraviolet light to kill all possible bacteria. In the end she becomes such that it scares me.

“Sorokina water can dissolve anything. Sorokina the water here is very, very unpleasant thing. It has the properties of acid and alkali,” says Uchida.

“Even a drop of this water can bring you so much trouble that you never dreamed of,” adds Wasco.

People traveling by boat in the reservoir, “Super-Kamiokande”

If you need to conduct maintenance inside the tank, for example for replacement of faulty sensors, the researchers have to use a rubber boat (pictured above).

When Matthew fry was a graduate student at the University of Sheffield he and two other students “lucky” to do the same work. By the end of the day, when it’s time to rise up intended for this purpose omit the gondola broke down. Physicists had nothing to do, how to go back in the boat and wait until it has been repaired.

“I didn’t know when she was lying on her back in this boat and talked with the others, as a tiny part of my hair, literally not more than three inches in length, touched the water,” says Malek.

While they swam inside “Super-Kamiokande”, and scientists upstairs was fixing the gondola, Malek nothing to worry. He was concerned early in the morning the next day, realizing that there was something terrible.

“I woke up at 3 in the morning the unbearable itching on the head. It was probably the most horrible itching I’ve ever experienced in my life. Worse than chickenpox, which I had in childhood. He was so awful that I just couldn’t fall asleep,” continued the scientist.

Fry realized that the drop of water that got on the tip of his hair, “sucked dry” of them all nutrients and their deficiency has reached his skull. He hastily ran to the shower and spent over an hour trying to restore my hair.

Another story told Vasco. He had heard that in 2000, the year when maintenance staff is pulled from the tank water and found at the bottom of the shape of a wrench.

“Apparently this key is accidentally left one of the employees when they filled the tank with water in 1995. After water in 2000, they found that the key disappeared”.

“Super-Kamiokande 2.0”

Despite the fact that “Super-Kamiokande” is already a very large neutrino detector, scientists have proposed to create a large installation called “Hyper-Kamiokande”.

“If we get approval to build “Hyper-Kamiokande”, the detector will be ready approximately in 2026,” says Vasco.

Under the proposed concept, the detector “Hyper-Kamiokande” is 20 times more “Super-Kamiokande”. It is planned to use about 99 000 photomultipliers.

Leave a Reply

Your email address will not be published. Required fields are marked *