Determination of LHC Main Dipole Field Errors during a Sector Test using Trajectory Analysis

During the installation phase of the LHC, a beam test of a complete LHC arc may be performed in the year 2006. One of the motivations for such a test is the experimental determination of the field errors of the main dipole magnets directly with beam. The possibility of obtaining useful information on certain field errors from an analysis of the trajectory response to orbit corrector kicks has been evaluated. The influence of monitor noise and calibration errors has been tested. This first study indicates that under the conditions that have been evaluated, it is possible to determine the average a2, b2 and b3 field errors of the main dipoles and the average b2 field error of the main quadrupoles and perform a check of the test bench measurements of the magnets during the sector test.