Vacuum Physics and Techniques PDF
Document Details
Uploaded by HappierLarimar2949
National Technical University of Athens
Tags
Summary
This document details various aspects of vacuum physics and techniques. It covers topics such as kinetic theory, types of vacuum pumps, including mechanical, diffusion, roots, turbo, absorption, and cryo pumps, as well as measurement methodologies and residual gas analysis. The document is suited for students learning about integrated circuit and sensor fabrication processes.
Full Transcript
VACUUM PHYSICS AND TECHNIQUES KINETIC THEORY OF GASES M-B DISTRIBUTION OF VELOCITIES MEAN FREE PATH d0= molecular diameter n=molecular density (mlcs/m3) Air...
VACUUM PHYSICS AND TECHNIQUES KINETIC THEORY OF GASES M-B DISTRIBUTION OF VELOCITIES MEAN FREE PATH d0= molecular diameter n=molecular density (mlcs/m3) Air at room temperature For two gases a and b Time of formation of a monolayer v=molecular velocity Conductance In series FLOW OF GASES In parallel In series In parallel Allowance Pumping speed Resistance Evacuation time IV. VACUUM PUMPS 1. Primary (mechanical) Pumps Operating Principle Double Stage Operating Principle SS + Gas Ballast Operating Principle Single stage 3. Roots Pumps 2. Diffusion Pumps Operating Principle Cooling Failure 4. Turbo Pumps 5. Absorption Pumps Operating Principle Ion Pumps 6. Cryo Pumps VII. MEASUREMENT OS LOW PRESSURES 1. Pirani Manometers 2. Baratron (capacitance manometer) 2. Baratron (capacitance manometer) 3. Ionization manometers a. Ionization manometers w cold cathode (Penning) b. Ionization manometers w hot cathode (Bayard-Alpert) VI. MISCELLANEOUS VACUUM TECHNIQUES Leak detector Residual Gas Analyzer
