A compact beam delivery system enabling ultra-fast dose delivery for upright proton therapy - Project Summary/Abstract This project aims to develop a compact fixed beamline solution incorporating Fixed-Field Alternating Gradient (FFA) technology and a novel ultra-fast energy degrader for ultra-rapid dose delivery in proton therapy. By leveraging the unique capabilities of this system, we seek to enhance the quality of proton therapy for patients and significantly reduce the treatment time and cost of proton therapy. In particular, by delivering each field in a few seconds, this system will enable effective and more efficient treatment of moving targets. At the same time, the higher patient throughput and significantly reduced costs of facilities hosting this compact system will improve the accessibility of proton therapy in the United States and worldwide. Moreover, up to 50% shorter treatment times will significantly improve patient comfort. The project is composed of three specific aims: (1) Ultra-fast beam delivery, (2) Beam transport fits within a single treatment room, and (3) Technology validation. Specific Aim 1 focuses on achieving ultra-fast dose delivery by designing and validating an ultra-fast energy degrader system capable of rapid beam energy changes. A full-size prototype of the degrader will be engineered by the industrial partner Pyramid Technical Consultants. This will be followed by the design of the FFA-based beam transport, enabling efficient energy switching and rapid dose delivery. The FFA lattice will be modeled and simulated in detail. Pyramid Technical Consultants will also develop a fast pencil beam scanning (PBS) system, which will be integrated into the beamline design. We will iteratively optimize the entire beam transport solution, considering clinical requirements for beam quality. Specific Aim 2 will ensure that the beam transport system fits within a single treatment room. This will involve designing the optics for a beam extraction segment, enabling compatibility within a compact treatment room the size of a LINAC vault. Two options for the treatment room will be investigated, including a compact ceiling-mounted synchrotron or a superconducting cyclotron to be paired with our system. Specific Aim 3 focuses on the validation of the developed technology. Experimental testing will be conducted to validate the degrader prototype and the fast PBS system, assessing their speed and accuracy of dose delivery. Furthermore, a down-scaled FFA magnetic beamline will be installed to demonstrate system feasibility and benchmark output beam parameters against detailed particle transport and tracking simulations. Successful completion of these aims will pave the way for the translation of the FFA technology combined with an ultra-fast energy degrader into a pre-commercial prototype of the compact beamline, offering a promising solution to expedite treatments, improve patient outcomes, and address the limited availability and high cost of proton therapy.