Multipacting mitigation by atomic layer deposition: the case study of Titanium Nitride

TL;DR

This paper explores using Atomic Layer Deposition to apply Titanium Nitride films on SRF cavities, effectively reducing multipacting phenomena by controlling film properties at the atomic level.

Contribution

It demonstrates a scalable ALD method to tune TiN film resistivity and electron emission yield, mitigating multipacting in superconducting RF cavities.

Findings

ALD enables precise control of TiN film properties.

Optimized TiN films reduce multipacting in SRF cavities.

Method can be adapted to other RF vacuum devices.

Abstract

This study investigates the use of Atomic Layer deposition (ALD) to mitigate multipacting phenomena inside superconducting radio frequency (SRF) cavities used in particle accelerators. The unique ALD capability to control the film thickness down to the atomic level on arbitrary complex shape objects enable the fine tuning of TiN film resistivity and total electron emission yield (TEEY) from coupons to devices. This level of control allows us to adequately choose a TiN film thickness that provide both a high resistivity to prevent Ohmic losses and low TEEY to mitigate multipacting for the application of interest. The methodology presented in this work can be scaled to other domain and devices subject to RF fields in vacuum and sensitive to multipacting or electron discharge processes with their own requirements in resistivities and TEEY values