The First Five Years 1992-1996 the Bell Jar Vacuum Technique and Related Topics for the Amateur Investigator Reference Number: FF0701 The First Five Years 1992-1996 © 1999, Stephen P. Hansen The content of this booklet is derived from articles which have appeared in the Bell Jar (ISSN 1071-4219), the quarterly journal of vacuum technique and related topics in physics for the amateur experimenter. Further information on this journal will be supplied on request from: the Bell Jar 35 Windsor Drive Amherst, NH 03031 www.belljar.net [email protected] Copyright 1999, Stephen P. Hansen No redistribution is permitted. Reference Number: FF0701 Contents Forward Vacuum: Means of Production, Measurement and Applications Part 1: Fundamentals and Tutorials Part 1A: Basics of Vacuum 1-2 Basics of Vacuum 1-2 Some Vacuum Fundamentals 1-2 The Writings of Michael McKeown 1-9 Backstreaming from Oil-Sealed Mechanical Pumps 1-21 Complete Dummies Guide to the Operation of a Typical Diffusion 1-23 Pumped High Vacuum System Manometers 1-26 Applications for Mechanical Diaphragm Manometers 1-36 Part 1B: Putting Vacuum Systems Together 1-39 An Amateur’s Vacuum System 1-39 Diffusion Pump Basics 1-43 Organization of a Diffusion Pumped System 1-47 A Simple Mini System for Evaporation 1-51 The Restoration of a High-Vacuum, Thin Film Deposition Machine 1-52 Adding Instrumentation to a High Vacuum Deposition Station - A Student 1-56 Project at Cambrian College Part 2: Vacuum Components and Bits & Pieces Refrigeration Service Vacuum Pumps 2-2 The Aerobic Workout Vacuum Pump 2-4 A Homebuilt Thermocouple Gauge Controller 2-5 Easy Gauging - In Praise of the Lowly Discharge Tube 2-8 More on Thermal Conductivity Gauges 2-10 Constructing a Pirani Gauge 2-14 How to Make a Glass to Metal Seal 2-16 Reconfigurable Glass Vacuum Chambers 2-20 A Simple, Flexible Chamber for Beam Experiments 2-24 A Kit of Components for Conducting Gaseous Discharge and Electron 2-28 Beam Experiments Part 3: Projects How to Make Buckyballs 3-2 Build a Pair of Magdeburg Hemispheres 3-6 Production of Very Low Temperatures 3-8 Introductory Vacuum Experiments 3-10 Constructing a Radiometer 3-13 A Cheap Metal Vacuum Chamber 3-14 A Simple Vacuum Stand 3-15 A Homebuilt Transmission Electron Microscope 3-16 The Production of Phosphors: An Introduction 3-21 A Brief Note on Solder Glass for Sealing 3-23 Copyright 1999, Stephen P. Hansen No redistribution is permitted. Reference Number: FF0701 Some Ideas for Electrical Feedthroughs 3-23 Gun for High Speed Particle Impact Testing 3-25 The Evolution of the X-Ray Tube 3-26 Generating X-Rays with Receiving Tubes 3-31 A Sorption Pumped X-Ray Tube 3-36 Geiger Counters and Power Supplies 3-37 Plasma Accelerators - An Introduction 3-44 A Coaxial Plasma Gun 3-47 New Life for Old Microwave Ovens 3-51 Microwave Miscellany 3-56 Apparatus Splits Glass Tubes Longitudinally 3-57 Some Resources and Ideas for Plasma Experiments 3-58 Some New Books in the American Vacuum Society’s Classics Series 3-63 A Brief Tutorial on the Glow Discharge (in 2 parts) 3-64 Some Experiments with Glow Discharge Produced Electron Beams 3-70 Demonstrate a Transmission Electron Microscope 3-75 The Multiplate Chamber (MPC) Electron & Ion Source 3-76 Build a Multiplate Chamber Beam Source 3-80 Something Different: Freeze-Drying 3-83 Compression Plates for Stacked Electrode Assemblies 3-84 Electron Optics Kits 3-87 Build a Plasma Sphere 3-88 Some Notes on Atmospheric Pressure Plasma Displays 3-91 Infrasound Monitoring with a Microbarograph 3-94 A Home-Grown, Sealed Carbon Dioxide Laser 3-100 Part 4: Musings Vacuum in the Amateur Scientist 4-2 Pathological Science 4-3 Some Recollections 4-5 Home-Made Geissler Tubes 4-8 Appendix: Some Suppliers Copyright 1999, Stephen P. Hansen No redistribution is permitted. Reference Number: FF0701 Forward The incentive for producing this compilation came from several factors: I was getting tired of handling the boxes and folders containing the hardcopy issues; My wife, Chris, was getting tired of these same boxes, strewn all around the upstairs bedrooms; Volume 1, originally produced on an obsolete word-processing typewriter, existed only in print form and the originals were getting rather dog-eared; Some of the later issues were in peril because a number of the electronic files had gotten corrupted; A certain percentage of each issue (classifieds and the like) had gotten outdated; The sets of back issues were beginning to cost more than I thought they should. As a result, I have finally produced the work now at hand. When I announced this project, over one year ago, I thought it would be pretty easy to pull up all of the files and stick them together in some coherent form. However, for some of the reasons noted above, and because I just had to tinker a bit, it turned into a larger project. In this compilation are all of what I feel are the useful articles from the 20 issues that comprised Volumes 1-5. To keep the length manageable and the content relevant, I did cut out the time-sensitive items and the various bits of commentary. I will keep my eye out for items that should have been retained in this compilation but fell through the cracks. They will be collected and will appear at some future date, either in the next compilation or in a regular issue. I did try to correct a few errors, although I’m sure that there are still a few lurking in these pages. As I find these (or they are brought to my attention) I will publish corrections in later publications and/or on line. Some attempt was made to group articles by topic so referring to a related article shouldn’t be difficult. Steve Hansen November 1999 The chart on the next page depicts how vacuum is produced (types of pumps), how it is measured (types of gauges) and how it is used. This compilation will touch on most of these items. Copyright 1999, Stephen P. Hansen No redistribution is permitted. Torr Production Measurement Application Characteristics 10 -9 High Vacuum Surface Science 11 Hot & High 10 -8 Pumps: Ultra 3.5 (10 )/L Accelerators Microscopes: 5 300 km Turbo, Cold 5.0 (10 ) cm X-Ray Tubes SEM, TEM, FIM 10 -7 Cryo-sorption, Cathode Electron Diffusion, 200 km Tubes Evaporated 10 -6 Ion Ion Gauges Films 10 -5 Vacuum Metallurgy High Molecular g Rotary -4 a 10 r D Vane Cold Cathode r 16 a 3.5 (10 )/L -3 l 10 with Ion, Atom, Electron u c 5.0 cm e Roots Sources l 100 km 10 -2 o km M Blower e g Sputtering Plasma Etch s u e a -1 e 10 g g e G u Low Pressure u c Freeze Dry a C a n G CVD T a Rotary G t 0 i 10 i m c n Medium Vane g Plasma Ashing a Transition a a r p r i Gas Lasers a GM Tubes ~ Piston h 10 1 P 19 C p 3.5 (10 )/L Pump a Neon Signs Sorption LP Arcs -3 Di 5.0 (10 ) cm 2 10 e CVD g Vacuum Distillation Low u 22 Convection Pirani Gauge Pirani Convection Dry Vane a 2.7 (10 )/L 3 10 G -6 n 6.6 (10 ) cm Viscous o d Atm Pressure 10 4 r u Plasmas o Molecules per Altitude >> Atm. B Range/ liter at 0º C above Regime Rev. 4, 2006 MFP (λ) cm Earth © Stephen P Hansen 1992 Reference Number: FF0701 Basics of Vacuum Background “Modern atomic physics is the child of the vacuum pump.” Karl K. Darrow, a researcher at Bell Laboratories, made this statement in his 1932 book “Electrical Phenomena in Gases.” Indeed, the development of vacuum pumps capable of reaching very low pressures has been intertwined with most of the advances in physics since the mid-nineteenth century. The simple low pressure electrical discharge tubes developed by Geissler and others quickly progressed from curiosities to devices with significant implications. The discovery of x-rays by Roentgen in 1895 represented a watershed. The identification of the electron and the invention of the cathode ray oscilloscope tube happened at about the same time. Other developments quickly followed: the vacuum tube made the radio industry possible and vacuum coating processes led to new types of optical elements as well as to integrated circuits. The scanning electron microscope, mass spectrometer, laser, computer, microwave oven, compact disk and even plasma treated tire cords would all be fiction without vacuum and vacuum processes. Unfortunately, even though it pervades our technology and our lives, vacuum is a field that has not been very accessible to the amateur and the non-specialist, mainly due to a severe lack of information specifically targeted toward that audience. Amateur vacuum experimentation did have a period of activity in the late 1950s and 1960s. For those who remember, two good examples were C.L. Stong’s Amateur Scientist column in Scientific American and the amateur oriented pumps, kits and plans once offered by the firm of Morris & Lee of Buffalo, NY. Between the two, an impressive array of apparatus emerged from the efforts of ambitious basement experimenters. Reported were a variety of gas lasers, x-ray tubes, potential drop accelerators, mass spectrometers, simple & compound electron microscopes and high altitude chambers, to name a few. All of these were cobbled together with converted refrigeration compressors, single stage diffusion pumps, copper & glass tubing, sealing wax and a lot of ingenuity.