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Surface characterization and SEY measurements. Available: XPS system ► provides surface chemical composition in the topmost 2 nm, by measuring the energy spectrum of photoelectrons excited by X-rays (h =1.2 or 1.4 KeV) from core levels.
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Surface characterization and SEY measurements Available: XPS system ► provides surface chemical composition in the topmost 2 nm, by measuring the energy spectrum of photoelectrons excited by X-rays (h =1.2 or 1.4 KeV) from core levels NB: XPS has lower effect of “scrubbing” than Auger e-gun (gets signal from a larger area, comparably lower current densities involved) Upgrade for SEY: ►additional UHV chamber and instrumentation (e-gun, flood-gun, picoamperemeter,UHV components)
E const -Vret Is +HV A B E const -Vret Is C E var Is +45V Ic
primary beam current D secondaries E var -20V or GND/+90V Is E E var Is +50V -/+50V secondaries backscatt.
What is the importance of: • Incidence angle dependence • Minimum primary energy • Energy distribution • Estimate of costs: 100K • e-gun 45K • Flood gun (home made) • Manipulator 12K • Data acquisition 15K • UHV 30K