Gadolinium, a rare-earth element often used in MRI contrast dye, will help scientists study supernovae. The Super-Kamiokande underground neutrino observatory in Japan was recently modified so it could detect neutrinos from distant supernovae.
Supernovae are massive explosions caused when very old stars implode upon themselves. Super-K uses water to catch neutrinos from supernovae. The observatory was only able to detect neutrinos from supernovae relatively close to Earth before the modification. Adding gadolinium to the water will allow the observatory to detect neutrinos from much more distant supernovae. This will allow scientists to better understand the history of the universe’s supernovae.
The observatory underwent a $10 million refurbishment from June 2019 to January 2020. It is located 1,000 meters underneath a mountain in central Japan’s Hida.
Super-K’s smaller predecessor Kamiokande detected the first supernova-sourced neutrinos in 1987. It detected 12 neutrinos from Supernova 1987A in the Large Magellanic Cloud, which orbits the Milky Way. Masatoshi Koshiba shared the 2002 Nobel physics prize for this achievement. That was, however, the last time supernova-sourced neutrinos have been detected.
Antineutrinos released by supernovae cause a neutron and positron to be released from water molecules. Gadolinium nuclei can capture the neutrons released much more effectively than the hydrogen and oxygen nuclei in water.
The idea to add gadolinium to Super-K came from Ohio State University’s John Beacom and the Kavli Institute for the Physics and Mathematics of the Universe’s Mark Vaginsin in 2004. Vagins spent a decade demonstrating the idea could work, building a $6 million neutrino detector in the process. That neutrino detector was given the name Evaluating Gadolinium’s Action on Detector Systems, a name with the humorous acronym EGADS. The gadolinium modification to Super-K has been given the name Gadolinium Antineutrino Detector Zealously Outperforming Old Kamiokande, Super! Its humorous acronym is GADZOOKS! The words egads and gadzooks are often found in superhero comics, denoting surprise.
Japanese physicists are hoping their government will fund an even bigger, more effective neutrino observatory called Hyper-Kamiokande. This would be a $50 million project and would hold 260,000 tons of water, over five times the capacity of Super-K.
The FDA warned in 2017 that gadolinium-based contrast agents (GBCAs) are retained in the body. GBCAs may cause gadolinium deposition disease, a proposed disease characterized by peripheral neuropathic pain, joint stiffness, buzzing sensation, fatigue, muscle spasms, headache, clouded mentation, distal extremity and skin substrate thickening, discoloration and pain.