4D Emittance Measurements Using Multiple Wire and Waist Scan Methods in the ATF Extraction Line.

Abstract

TUPC087International audienceEmittance measurements performed in the diagnostic section of the ATF extraction line since 1998 lead to ver- tical emittances three times larger than the expected ones, with a strong dependence on intensity. An experimental program is pursued to investigate potential sources of emit- tance growth and find possible remedies. This requires ef- ficient and reliable emittance measurement techniques. In the past, several phase-space reconstruction methods devel- oped at SLAC and KEK have been used to estimate the ver- tical emittance, based on multiple location beam size mea- surements and dedicated quadrupole scans. These methods have been shown to be very sensitive to measurement er- rors and other fluctuations in the beam conditions. In this context new emittance measurements have been performed revisiting these methods and newly developed ones with a systematic approach to compare and characterise their per- formance in the ATF extraction line