LEBT Chopper System: System Design Document (SDD)

The Low Energy Beam Transport (LEBT) chopper creates a required beam time structure by chopping out (removing by deflecting from the beam path) unwanted parts of a continuous beam transported from the ion source to RFQ in LEBT. The unchopped parts of the beam propagate through the LEBT, while the deflected parts are deposited on an absorbing target. The chopper system in general consists of a deflecting structure, where the beam-deflecting fields are created, and a pulse generator that feeds this structure with voltage pulses having the required time pattern. The system should turn deflection on and off within a short time interval, because the beam parts within the pulse front and end will be only partially deflected and will form unwanted tails of the beam pulse downstream. This can be achieved with traveling slow-wave chopper structures where the field propagates with the same velocity as the beam, as illustrated in Fig. 1.. Authors: Kurennoy, Sergey S. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000328549647); Grumstrup, Torben Peter [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000244702923); Alvarez Prieto, Juan Diego [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0009000376215243); Braido, Anthony Jeffrey [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0009000481320897); Carlisle, Christopher Lee [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)]. DOE Contract: 89233218CNA000001. Subjects: 43 PARTICLE ACCELERATORS; Accelerator Design, Technology, and Operations