Building of next-generation experimental gear is being pursued at Yemilab, a multipurpose underground analysis facility positioned 1,009 meters beneath the summit of Mount Yemi in Jeongseon County, Gangwon Province, South Korea, to research stellar evolution processes and neutrino properties. The thick bedrock right here blocks cosmic ray particles raining down from the floor, creating an surroundings advantageous for capturing uncommon and weakly occurring particle reactions.
So Jung-ho, a senior engineer on the Institute for Primary Science (IBS) Yemilab, and Kim Younger-deok, director of IBS’s Heart for Underground Physics, are every advancing plans to construct the underground accelerator “YUNA@Ok” and the neutrino detector “νEYE.” Each devices are anticipated to grow to be key instruments for understanding basic bodily phenomena within the universe.
YUNA@Ok: An Underground Accelerator to Recreate Stellar Evolution
YUNA@Ok, proposed by Senior Engineer So, stands for “Yemi Underground Nuclear Astrophysics at Korea.” It’s an accelerator designed to recreate nuclear reactions similar to fusion occurring inside stars and to review how the weather that make up stars had been fashioned.
To enhance the efficiency of an accelerator—which accelerates particles similar to protons utilizing electrical fields to induce collision reactions—both an extended acceleration part or greater voltage is required. Nevertheless, within the space-constrained underground surroundings, extra nuclear reactions are induced by rising the particle beam present to spice up the variety of particles.
At the moment, solely three services worldwide function underground accelerators: CASPAR in america, LUNA in Italy, and JUNA in China. LUNA, a big underground accelerator just lately inbuilt Italy, can produce energies of as much as roughly 3.5 MeV (mega-electron volts) for protons. An electron volt is a unit representing the vitality of a single particle, with 1 MeV equal to 1 million electron volts.
The goal vitality for YUNA@Ok envisioned by Senior Engineer So is 6 MeV for protons and 9 MeV for alpha particles—ranges far exceeding current services. “The purpose is to look at nuclear reactions that nobody on the earth has ever seen, in high-energy regimes that current services haven’t reached,” he mentioned.
When voltage is elevated and particle vitality rises, positively charged atomic nuclei can extra simply overcome the “Coulomb barrier”—the repulsive pressure between them—to set off fusion reactions. This enables the analysis scope to increase to nuclear reactions involving carbon and oxygen, which have greater Coulomb obstacles. In stars the place hydrogen fuses into helium, heavier parts similar to carbon, oxygen, and magnesium are produced relying on the evolutionary stage. The extra exactly nuclear reactions involving heavy parts are measured, the nearer scientists get to elucidating stellar evolution.
Senior Engineer So mentioned, “We’re at the moment discussing particular analysis plans with home researchers together with Cheon Myung-ki, director of Soongsil College’s Heart for Excessive Nuclear Astrophysics, Ahn Jung-keun, professor of physics at Korea College, and Hahn In-sik, director of IBS’s Heart for Unique Nuclear Research.”
νEYE: Observing Low-Vitality Neutrinos with an Oil-Stuffed Detector
Yemilab has a big cylindrical experimental house measuring roughly 20 meters in each diameter and depth. Director Kim is reviewing plans to put in a neutrino detector of roughly 2 kilotons, referred to as νEYE, on this house. νEYE stands for “Neutrino Experiment at YEmilab.”
Neutrinos are elementary particles with no electrical cost and intensely small mass. They’re produced in fusion reactions contained in the Solar, supernova explosions, and nuclear fission processes in reactors. They barely work together with different matter and may move straight by means of the Earth—which additionally makes them extraordinarily tough to detect.
Neutrino detectors are likewise affected by background noise from muons produced by cosmic rays and pure radiation, so detectors should be put in deep underground to tell apart the faint indicators left by neutrinos.
Neutrino detection strategies differ relying on the fabric filling the detector. Detectors stuffed with water, similar to Japan’s Tremendous-Kamiokande and Hyper-Kamiokande, use the “Cherenkov technique.” The Cherenkov impact happens when a charged particle travels sooner than the pace of sunshine in water, emitting blue mild. Water is cheap and straightforward to acquire, making it advantageous for constructing massive detectors on the size of tons of of 1000’s of tons.
The νEYE envisioned by Director Kim makes use of oil (natural solvent) as a substitute of water, using the “liquid scintillator” technique. When a neutrino interacts with particles within the liquid scintillator, a quick flash of sunshine is produced, which is captured by optical sensors put in across the detector.
A comparability of main underground accelerators and neutrino detectors is as follows:
| Facility | Nation | Sort | Vitality/Scale |
|---|---|---|---|
| LUNA | Italy | Underground accelerator | As much as 3.5 MeV for protons |
| CASPAR | United States | Underground accelerator | — |
| JUNA | China | Underground accelerator | — |
| YUNA@Ok (proposed) | South Korea | Underground accelerator | 6 MeV for protons, 9 MeV for alpha particles |
| Tremendous-Kamiokande | Japan | Neutrino detector | Water (Cherenkov technique) |
| νEYE (proposed) | South Korea | Neutrino detector | ~2 kilotons, oil (liquid scintillator technique) |
Be aware: Vitality figures for CASPAR and JUNA weren’t included in publicly out there information.
The νEYE development plan has at the moment been submitted to South Korea’s Ministry of Science and ICT as a brand new large-scale infrastructure R&D venture. Director Kim mentioned, “The purpose is to extend detector sensitivity inside Yemilab’s restricted house to look at decrease vitality regimes,” including, “We will reveal properties of neutrinos that haven’t but been sufficiently studied, together with photo voltaic neutrinos.”
A New Hub for Cosmic Origins Analysis
Yemilab has already established itself as an vital hub for underground experiments, together with darkish matter searches. With the development of YUNA@Ok and νEYE now being pursued, the power is anticipated to safe worldwide competitiveness in analysis on stellar evolution and neutrino properties.
Specifically, YUNA@Ok will pioneer vitality regimes not reached by current underground accelerators, enabling analysis on nuclear reactions involving carbon and oxygen. That is anticipated to supply vital clues for understanding late-stage stellar evolution and the formation of heavy parts.
νEYE is specialised for low-energy neutrino commentary by means of the liquid scintillator technique. Exact measurement of photo voltaic neutrinos may present key info for understanding the Solar’s inside construction and fusion processes. The scientific group anticipates that each experiments will play vital roles in elucidating the origins and evolution of the universe.
