To push the limits of current insertion device (ID) technology and benefit synchrotrons and free electron lasers, a new cryogenic permanent magnet undulator (CPMU) has been developed. This development explores short-period undulators with unprecedented combinations of short periods and high magnetic fields. The innovative CPMU, featuring a 1-meter-long prototype with a 12 mm period, has been successfully delivered.

The CPMU design has advanced to a more mature stage, addressing the challenges of short periods while enhancing the magnetic field. Significant improvements over conventional CPMUs have been thoroughly assessed optimizing magnetic materials and cooling techniques to achieve higher performance and reliability.

The focus on short-period undulators is driven by the need for higher brilliance and more compact radiation sources. By reducing the period length and increasing the magnetic field strength, the CPMU can generate higher harmonics, essential for scientific applications in materials science, biology, and chemistry.

This project is part of the LEAPS-INNOV initiative. The CPMU was designed under the leadership of SOLEIL and ESRF, with the prototype built at SOLEIL.