The AT-MAS Field Quality Observatory Main Quadrupoles

This web site contains updated graphs of field quality measured in the Large Hadron Collider Quadrupoles at the manufacturer and comparison to beam dynamics targets. LHC main quadrupoles are built by a CERN-CEA collaboration under the responsibility of T. Tortschanoff (AT-MAS-MQ section). This analysis is carried out by the AT-MAS-MA section as a support to the follow up of the production and steering of field quality towards beam dynamics targets.

Instructions: to reduce the probability of activating IE and Excel bugs, please do not open files from your browser but save them on your disk (on IE, place your mouse on the link, then right mouse and Save target as ...). Then, please open them with the disabled macro and no update options. You need a NICE password to download the files. For problems in file downloading please contact authors.

Collared coils are identified by a progressive number. Comparison with targets is carried out by assuming that unallowed harmonics have the same value in the collared coil and at 1.9 K, and that only allowed components at injection are shifted by the persistent current as measured for the prototypes (b6=-4.0, and zero for b10 and b14). The contribution of the beam screen is taken into account in the targets. Data at 300 K are locally re-centered using feed-down of b2 on b1 and a1 at first order. We assume a target of 0 units for all systematics at injection, and the target for the random as given in the 9901 table. We acknowledge F. Simon, M. Durante, CEA and Accel teams for providing the data at 300 K and MTM-MA section for data on prototypes at 1.9 K.

Excel files with magnetic measurements of each collared coil or cold mass at room temperature can be found in the LHC main quadrupole data repository.

Disclaimer: Please note that these measurements are the result of the efforts and collaboration of many people. However these results are not final. You can consult data, but before using them you are kindly requested to ask the permission from the authors.