At the KEKB B-Factory, the total integrated luminosity accumulated by the Belle detector reached 1000 fb-1 on November 29th 2009, which was one of the initial goals of the KEKB project.

The Belle detector was installed in the KEKB accelerator in May 1999. This new luminosity record was accomplished ten and a half years after the installation. The accumulation of 1000 fb-1 is a world record for integrated luminosity; KEKB also has achieved the world's highest instantaneous peak luminosity. The figure below shows the history of the integrated luminosity at KEKB/Belle. This record was accomplished through a combination of various efforts including increasing beam currents by overcoming a number of vacuum troubles as well as suppressing the effects of the photo-electron clouds by installing solenoid coils all around the positron ring. To accumulate integrated luminosity at a higher rate, it was important to reduce the frequency of machine problems and to keep the beams operating stably without beam aborts, in addition to increasing the peak luminosity. In this sense, the achievement of this record is the fruit of the efforts of all members who have been concerned with KEKB including the staff of the facilities division and the injector. 

Source: KEK Website