Characterization CNM Proposal Slade J Jokela Igor V

Purpose • Our goal is to determine what is responsible for the ageing of

Equipment • Four-point non-destructive probe (can be used as STM) • SEM for positioning

Procedure • Examine sample under SEM, STM, and AES • Determine Secondary Emissive Yield

Variations • Sample heating up to 500 °C for examination of thermal desorption/diffusion. –

What needs to be done • Equipment needs to be checked out by CNM

Vacuum Transfer System • This is for the characterization instrument (XPS, UPS, LEED) in

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Characterization: CNM Proposal Slade J. Jokela, Igor V. Veryovkin, Alexander V. Zinovev

Purpose • Our goal is to determine what is responsible for the ageing of secondary electron emissive materials. – Will examine changes in surface composition and structure under electron exposure – This experiment will not perfectly emulate normal MCP ageing as it must be carried out in a limited time. High electron flux must be used to complete experiment in the allotted time.

Equipment • Four-point non-destructive probe (can be used as STM) • SEM for positioning of probe can be used for surface examination • Gemini column for high resolution (energy and spatial) mapping of surface chemical composition using Ager Electron Spectroscopy (AES).

Procedure • Examine sample under SEM, STM, and AES • Determine Secondary Emissive Yield (LEED System) • Expose small sample area to some fluence of electrons from (LEED System) – Start with large fluence to see if there is a detectable change, then perform smaller fluence exposures to determine dynamics • Repeat…

Variations • Sample heating up to 500 °C for examination of thermal desorption/diffusion. – Especially carbon • Gas exposure for examining effects on composition and morphology. – Primarily interested in atmospheric gasses

What needs to be done • Equipment needs to be checked out by CNM – Voltage Sources • Plan on starting measurements in July or August. – Still need to check calendar at CNM

Vacuum Transfer System • This is for the characterization instrument (XPS, UPS, LEED) in building 200 -D 110. • Discussion between Hau Wang, myself, and Igor have resulted in shared costs for this hardware – Some items remain to be purchased • Vacuum Chamber ($1840) • Machining (Estimates must be made)