An automatic finder of field defects in a large A.G. machine

A series of program modules has been written in C, which can perform various tasks to analyze closed orbit measurements. They have been grouped into a software package which can be used by an operator to find field defects from orbit measurements. The basic algorithms used are well known and simple, based on fitting betatron oscillations. The effort has been put in the execution speed and ease of use. New algorithms have been introduced to detect wrong measurements and check the relevance of the kick calculation, which are a decisive step towards automatisation. It is presently possible to localize all relevant dipole field defects in a machine as large as LEP within less than one hour, including the check of the orbit readings.<>