Variable-spot ion beam figuring

TL;DR

This paper presents a novel variable-spot ion beam figuring method that adjusts the ion beam spot size during scanning to enhance process reachability and adaptability, supported by simulation results.

Contribution

It introduces a new variable-spot IBF scheme with a unique algorithm and integral etching time concept, improving upon conventional dwell time methods.

Findings

Simulation verifies feasibility and practicality

Enhanced reachability and process adaptability

Potential as a promising alternative to conventional IBF

Abstract

This paper introduces a new scheme of ion beam figuring (IBF), or rather variable-spot IBF, which is conducted at a constant scanning velocity with variable-spot ion beam collimated by a variable diaphragm. It aims at improving the reachability and adaptation of the figuring process within the limits of machine dynamics by varying the ion beam spot size instead of the scanning velocity. In contrast to the dwell time algorithm in the conventional IBF, the variable-spot IBF adopts a new algorithm, which consists of the scan path programming and the trajectory optimization using pattern search. In this algorithm, instead of the dwell time, a new concept, integral etching time, is proposed to interpret the process of variable-spot IBF. We conducted simulations to verify its feasibility and practicality. The simulation results indicate the variable-spot IBF is a promising alternative to the conventional approach.