Computing and Library Services - delivering an inspiring information environment

MEIS studies of oxygen plasma cleaning of copper for fast response time photocathodes used in accelerator applications

Noakes, T., Mistry, S., Cropper, M.D., Rossall, Andrew and Van den Berg, Jakob (2016) MEIS studies of oxygen plasma cleaning of copper for fast response time photocathodes used in accelerator applications. In: High Resolution Depth Profiling Workshop (HRDP08), 7, Western University, London, Ontario, Canada.

Metadata only available from this repository.


The performance of a fourth generation light source is to a greater extent reliant on the properties
of the electron bunches, with the fundamental limit controlled by the photocathode where the
electrons are emitted. Normally conducting RF guns often use metal photocathodes, mainly due
to their fast response time that allows very short pulses to be generated. However, they typically
have very low quantum efficiency (QE) compared to semiconductor alternatives (GaAs or
Cs2Te). The drive to use higher QE metals is motivated by the need to minimize the laser power
required to generate sufficient bunch charge for the downstream accelerator.
The use of Cu as the metal photocathode of choice is long standing. However, the preparation of
an atomically clean surface is thought to be key to achieving a high enough QE to be used in an
RF gun. At STFC Daresbury laboratory a preparation procedure has been developed that has
allowed a QE of approximately 10-5 to be achieved. This coupled with a high power UV laser
system has allowed electron bunches of up to 250 pC to be generated in the Versatile Electron
Linear Accelerator (VELA) facility [1]. However, there is very little understanding of how the
cleaning procedure leads to the required surface properties for electron emission and hence a
detailed study has been initiated.

Item Type: Conference or Workshop Item (Speech)
Subjects: Q Science > QC Physics
Schools: School of Computing and Engineering > International Institute for Accelerator Applications
School of Computing and Engineering
Related URLs:
Depositing User: Andrew Rossall
Date Deposited: 03 Nov 2016 15:28
Last Modified: 28 Aug 2021 12:08


Downloads per month over past year

Repository Staff Only: item control page

View Item View Item

University of Huddersfield, Queensgate, Huddersfield, HD1 3DH Copyright and Disclaimer All rights reserved ©