Vol.05 Hida Space Science Museum KamiokaLab

You can see miniature models and videos showing the interesting construction work needed for building Super-Kamiokande, including the excavating work, installation of Cherenkov light detectors (photomultiplier tubes), and the two-month job of supplying 50,000 tons of pure water into its huge tank.

Science communicators at the KamiokaLab give easy-to-understand descriptions. (Photo shows visitors in a scheduled group tour.)

Miniature models illustrate the task of installing photomultiplier tubes. More than 10,000 photomultiplier tubes were installed on the inner sides of the huge tank with a height of 40 meters (131 feet). It must have been a tough job!

This is a display duplicating the interior of the water tank in Super-Kamiokande. Photomultiplier tubes were installed here using the same materials and techniques as used in the actual construction work. (For safety reasons, these photomultiplier tubes do not hold a vacuum but are instead filled with nitrogen.) There are other interesting display methods….

This display is so exciting and realistic you will feel as if you are actually swimming inside Super-Kamiokande! You will see the overwhelming sight of endless arrays of photomultiplier tubes both above and below! In the KamiokaLab, there are indeed many interesting ideas and displays that help understand neutrino research and leave visitors feeling thrilled and satisfied.

I felt as if I were on a spaceship…. It was a continual thrill from the very first minute.

A shower of neutrinos!

Now going into Super-Kamiokande through the mine tunnel inside Mt. Ikenoyama.

Observing neutrinos from inside Super-Kamiokande!

All matter in our world is made up of atoms. In the center of an atom is a nucleus that consists of extraordinarily tiny elementary particles. Yet, I am told that neutrinos are even tinier and lighter when compared to these elementary particles. In the game shown in the photo above, use your hands to catch atoms projected on the screen and then paste them onto another type of atom to create, for example, water or other substances around us.

This is an interesting display demonstrating the property of neutrinos that lets them pass through anything. Here, a small ball representing a neutrino easily passes through the black shield placed in the middle of the path!?

Neutrinos pass through everything, but in very rare cases they collide or interact with matter. Super-Kamiokande detects the light emitted when a neutrino collides with the nucleus or electron of an oxygen or hydrogen atom in water and then analyzes the acquired data in detail to find the energy, type, and direction of the neutrino. The game shown above lets you roll a white ball (representing a neutrino) to fall into a black circle (representing the nucleus or electron of an oxygen or hydrogen atom) to cause light emissions. It looks easy but is actually quite difficult! That is why neutrinos rarely cause light emissions. This game helped me learn how difficult it is to observe neutrinos in action!

One neutrino “changes” into another neutrino!? This fact was first discovered at Super-Kamiokande. There are three types of neutrinos. In the game shown in the photo above, when a “tau neutrino” starts flying around, try touching it! Its speed gets faster and faster and it quickly changes into another type of neutrino. This is very exciting to watch! The fact that one neutrino changes into another type of neutrino seems to prove that neutrinos have mass. I learned that many scientists all around the world were excited about this great discovery.

This is a miniature model of Mt. Ikenoyama where the Kamioka mine is located. Let’s take a peek inside of the mountain by gripping the handles and lifting off the top!

Besides Super-Kamiokande, KamLAND and KAGRA were also built to conduct low-background experiments.

This is a miniature model of KAGRA, a facility that supports the challenge of observing gravitational waves directly by using a technique known as interferometry. I’m told that if we can detect and utilize gravitational waves then we could observe states dating back to when the universe was born that would be impossible to capture with light!

A life-size panel of Dr. Takaaki Kajita who directed the experiments at Super-Kamiokande and won the Nobel Prize in Physics in 2015 for the discovery that “neutrinos have mass.” How about getting a picture of yourself shaking hands with him!

The final display zone also shows a lot of things including a live video of the experiments at Super-Kamiokande, an introduction to the researchers, a Q&A corner, and a picture-story show. You can also listen to public discussions and short lectures by science communicators. I would really like for you to check out the schedule and visit here!