Development of a full scale superconducting undulator module for the ILC positron source

An undulator based positron source is the baseline for the International Linear Collider (ILC). The HeLiCal collaboration in the UK is working on the development of a full scale 4-m long undulator module. Several prototypes have been built and tested in the R&D phase of the programme that culminated in the development of manufacturing techniques suitable for construction of the first full scale undulator sections. This paper details the design and the construction status of 4-m long undulator module.