Speaker
Description
SuperKEKB is a double-ring collider consisting of a 7-GeV electron ring (HER) and a 4-GeV positron ring (LER) with a circumference of approximately 3 km, constructed by reusing the KEKB tunnel. To further increase the peak luminosity, “Nano-beam scheme with large crossing angle” is adopted. Electrons and positrons collide at a larger horizontal crossing angle while maintaining the bunch length about the same as that of KEKB. Therefore, the actual collision area can be considerably shorter than the bunch length. This mitigates the hourglass effect that results from colliding over the entire length of the bunch and allows a strong vertical squeeze to increase luminosity.
SuperKEKB was commissioned for 4 months in 2022 and now it has entered Long Shutdown 1 (LS1) for approximately 15 months. Various upgrades are currently underway. The beam currents were increased gradually, and the maximum of 1145 mA and 1460 mA were stored in the HER and LER, respectively. The peak luminosity of 4.7 ×10^34 cm-2 s-1 with a vertical beta function (βy*) of 1 mm at the collision point was achieved, breaking the previous year’s SuperKEKB world record in June 2022. The recent progress will be presented, and then the problems and issues to be overcome will be discussed along with the upgrade work during LS1 for further improvement of the luminosity performance.
| Collaboration / Activity | SuperKEKB |
|---|
