Functionality and performance of the multichannel Mott electron polarimeter iMott

A prototype of the multichannel Mott electron polarimeter nicknamed iMott, based on imaging-type electron optics, has been tested at the scattering energy of 20 keV. The working principles of iMott’s electron optics were systematically analyzed through numerical simulations and experimental calibration. The polarimeter demonstrates the ability to transfer electron images from a hemispherical analyzer to the scattering target and then to position-sensitive direct-electron detectors. The possibility of keeping the minimum resolution degradation is shown. Despite the inherent inefficiency of Mott scattering, the multichannel design provides significant advantages, including faster signal accumulation, as well as post-measurement adjustable resolution and count rate. Preliminary calibration with unpolarized electrons has been performed. Challenges such as the detector frame rates, high-voltage insulation, and ultra-high vacuum compatibility were identified, offering a roadmap for future instrumental progress of the iMott.