Carbon Film in Radio Frequency Surface Plasma Source with Cesiation

TL;DR

This paper investigates how carbon film deposition affects cesiation in RF surface plasma sources, showing that carbon films sustain cesiation longer with lower cesium consumption despite higher work functions.

Contribution

It reveals that carbon films maintain cesiation longer than metals or semiconductors, offering a potential improvement for RF surface plasma sources.

Findings

Carbon films sustain cesiation longer than metals or semiconductors.

Work function of graphite with alkali deposition is higher and lacks a minimum.

Carbon films can operate with lower cesium consumption.

Abstract

It is assumed that persistent cesiation in the SNS RF SPS is related to deposition of carbon film on the collar converter. The work function dependence for graphite with alkali deposition has no minimum typical for metals and semiconductors and the final work function is higher. For this reason, the probability of H- secondary emission from cesiated metal and semiconductors can be higher than from cesiated carbon films but the carbon film maintains cesiation longer and can operate with low cesium consumption.