Optics measurements and corrections at the early commissioning of SuperKEKB

We present experimental results of measurements and corrections for the optics at the early Phase-1 commissioning of SuperKEKB. The aim of SuperKEKB is a positron-electron collider built to achieve the target luminosity of 8x10^35 cm^−2s^−1. We have three stages; Phase-1 is the commissioning of the machine without the final focus magnets and detector solenoid(no collision); the collision with the final focus system and the Belle II detector will be performed at Phase-2 and Phase-3. The strategy for the luminosity upgrade is a novel "nano-beam” scheme found elsewhere[1]. In order to achieve the target luminosity, the vertical emittance has to be reduced by corrections of machine error measured with an orbit response. The vertical emittance should be achieved to be less than 10pm(∼0.2% coupling) during Phase-1 by fully utilizing correction tools of skew quadrupole-likecoils wound on sextupole magnets and power supplies for each correction coil in quadrupole magnets.