Tecnología para Campanas deVacío

QUIM 6216Dra. J. Torres

Partes de una campana de vacío y deun sistema de análisis de superficies

"gate"transferenciade muestra

pistolade iones

instrumentode medición

Conexiones “Flanges”

Conexiones y Sellados“Flanges and Seals”

Elastomeric Gasket:• Buna-N (nitrile rubber-NBR)• Silicone,• fluorocarbon (e.g. Viton-FKM)

Conexiones y Sellados“Flanges and Seals”

Valves

Creating Vacuum

• Compression and gas transfer pumps• Entrapment or go getter pumps

Rotor Vane (Mechanical Pump) Rotary Vane (Mechanical) Pump

Turbomolecular Pump

Diffusion Pump

Sorption Pump

Sublimation Pump

TSP for Titanium Sublimation Pump

Sputter Ion Pump Sputter Ion Pump

Cryopump

System Bakeout

External bakeout Internal bakeout

Diaphragm Gauge

Measuring Pressure• Mechanical Gauges

– have liquid or solid diaphragms that change positionunder the force of all the gas molecules bouncing offthem. These gauges measure absolute pressuresunaffected by gas/vapor properties. Unfortunately, thistype of gauge is ineffective below 10-5 Torr.

• Gas Property – Gauges– measure a bulk property, such as thermal conductivity or

viscosity. They are dependent on gas composition andare effective over limited pressure ranges belowapproximately 100 Torr and above 10-4 Torr.

• Ionization Gauges– The residual gas molecules are ionized by electrons and

the resulting ion current measured. Ionization gaugescover the pressure range from 10-4 Torr to 10-10 Torr.

Capacitance Manometer

Bourdon Gauge

Thermocouple Gauge

Pirani Gauge

Bayard-Alpert Ion Gauge Cold Cathode Ion Gauge