A Report on the Ground at KEK: Electrons and Positrons Collide for the first time in the SuperKEKB Accelerator

At 0:38am (GMT+09:00), April 26, 2018, several hours after KEK accelerator team found the collision point of electrons and positrons accelerated and stored by the SuperKEKB accelerator, one hadronic event produced by electron-positron annihilation (matter-antimatter annihilation), was reconstructed and displayed on a screen by the Belle II detector at the Tsukuba campus of KEK in Japan.

People involved in this project said cheerfully, “It is the result of our great efforts to overcome difficulties”, “I am so relieved to see the first collisions that we have long been waiting for”, “This is the real start of Belle II experiment.” They managed to make first tuning of the nano-beam scheme, overcome many difficulties and finally reached the first collisions.

………..

Accelerator tuning of SuperKEKB entered the final stretch on the night of April 25th. When the last vertical tuning of the beams for collision finished successfully at 8:15, around 30 researchers and engineers involved in the tuning erupted into cheers at the SuperKEKB accelerator control room. Soon after they confirmed the stability of beam, they handed over the baton to the Belle II team. The Belle II team began to raise the high voltage on its detectors to observe particle reactions. The physics run started at 10:10pm.

Sauce: https://www2.kek.jp/ipns/en/release/first-collision/

Article from April 2018. I hadn't heard of the KEK Laboratory; so did some digging. If already

covered, please disregard.

Additional links:

Wiki, for an overview

https://en.wikipedia.org/wiki/KEK

Under Secretary for Science of U.S. DOE visited KEK

https://www.kek.jp/en/newsroom/2018/10/18/1300/