Both in-vacuum undulators (IVUs) and cryogenic permanent magnet undulators (CPMUs), each important to third-generation light sources, are best characterized in their operating environment. To create a precision Hall probe map of an IVU/CPMU (IVU hereafter), an in-vacuum magnetic measurement (IVMM) system is proposed. Point-by-point measurement of field and trajectory error informs corrective tuning.

A novel design concept for a universal IVMM System has been developed and explored. The IVMM seals to the rectangular Ultra High Vacuum (UHV) flange of the IVU and shares its common vacuum space. Moreover, a modular design permits a wide range of IVUs of varying magnetic length to be mapped with a single IVMM, and is thus cost effective when multiple IVUs of varying configurations are planned. Here we review aspects of the modular IVMM design concept.