Improved Multi-dimensional Bunch Shape Monitor

Measuring longitudinal beam parameters is important for operation and development of high intensity linear accelerators, but it is notoriously difficult for ion beams at non-relativistic energies. The Bunch Shape Monitor BSM) is a device used for measuring the longitudinal bunch distribution in a hadron linac. However, the existing BSM models have poor electron collection efficiency from the wire and are limited to one dimensional measurements of the phase coordinate. While there is great potential for using BSMs in advanced beam dynamics experiments, the technical limitations of the existing design make it difficult. In response to this problem, RadiaBeam proposes to develop a BSM with improved performance that incorporates three major innovations. First, the collection efficiency will be improved by adding a focusing field between the wire and the entrance slit. Second, a 10-20x improvement in the measurement speed will be achieved by sampling longitudinal profiles of multiple energy slices simultaneously. Finally, the design will be augmented with both a movable wire and a microwave deflecting cavity to add functionality and enable measuring the transverse profile as a wire scanner. In Phase I, we will perform the electromagnetic design, including beam dynamics studies, of the beam focusing system to improve the collection efficiency by an order of magnitude. This will be followed by the design of a point-to-point wire-to-screen guidance system with a goal of improving the measurement speed by another order of magnitude. The proof-of-concept design activities will also include the engineering design of the movable wire and deflector system. The proposed instrument can be used not only in numerous scientific ion accelerators across the world LANSCE, FRIB, EIC, ATLAS, PIP-II, ESS, FCC, RIKEN etc.) but also in many industrial and medical accelerators for ion implantation, PET isotopes production, ion therapy, nuclear energetics and materials irradiation.