Uniform transverse beam profile with a new type of nonlinear magnet

Abstract

Abstract:In this paper, a new type magnet is proposed and processed to uniform the transverse beam profile. Compeared to the octupole, the new type magnet can prove a similar octupole magnet field in the middle, but the rise rate declines quickly in the edge. So that, a same uniform beam is got with less particles loss. Besides that, a mechanical structure is added to adjust the width of the middle region to satisfy different transverse dimensions, and this whould further reduce particles loss. Some numerical simulations have been done respectively with the octupole and the new type of magnet to show the advantages of the new type magnet.

Investigation into the Uniformization of Proton Beams for FLASH Therapy

“…. n. The formula for calculating non-uniformity is defined as [30]: From left to right, the figures correspond to the selection of horizontal and vertical grids from the 5th to the 16th. Specifically, the middle picture selects horizontal grids ranging from the 5th to the 16th and the vertical grids range from the 3rd to the 17th.…”

“…The coordinates of each grid are determined by the indices 𝑖, 𝑗, where 𝑖 and 𝑗 represent the horizontal and vertical directions, and the particle count in each grid is denoted as 𝑁 , 𝑖, 𝑗 = 1 … 𝑛. The formula for calculating non-uniformity is defined as [30]:…”