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Vacuum Technology and the Amateur Steve Hansen

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Title: Vacuum Technology and the Amateur Steve Hansen


1
Vacuum Technology and the Amateur Steve Hansen
the Bell Jar www.belljar.net
www.mksinst.com
2
Influences
  • C. L. Stong and The Amateur Scientist
  • Franklin B. Lee (founder of Morris Lee, now
    Science First)
  • John Strong and Procedures in Experimental
    Physics
  • Frank Früngel and High Speed Pulse Technology
  • My parents

3
The Importance of Vacuum
  • Modern atomic physics is the child of the vacuum
    pump.
  • Karl K. Darrow, Bell Labs, 1932
  • Vacuum technology is largely secondary in that
    it is a part of other
  • technologies that are central to analysis,
    research, development and
  • manufacturing. It is used to provide a process
    environment. Many
  • advances in vacuum technique have resulted from
    the demands of
  • other technologies, although scientists and
    engineers have studied
  • vacuum for its own sake.
  • John F. OHanlon, A Users Guide to Vacuum
    Technology, 1989

4
The Appeal of Vacuum E.R. Brown
  • Every TN (Telescope Nut) has probably had the
    desire to aluminize his own mirrors and
    anti-reflection coat his own lenses...but has
    felt that the equipment for doing this work was
    so complicated and expensive that it was not
    worth while…
  • Coating lenses and aluminizing mirrors,
    however, is only a small part of the work which
    can be performed by high vacuum equipment, and
    the processes of which it is capable offer a
    fascinating field for the TN with his mechanical
    ingenuity and intellectual curiosity....
  • Not the least of the appeal of high vacuum to
    the TN is its natural perversity. Compared to
    high vacuum systems, the most recalcitrant
    optical surface is a paragon of meek
    submissiveness. This sort of thing makes raving
    maniacs of most people, but TNs are of the
    peculiar breed of cat which thrive on
    frustrations.
  • Earle R. Brown, ATM3, 1953

5
The Appeal of Vacuum C.L. Stong
  • One of the first steps in most experiments is
    to provide the immediate environment in which the
    experimental event can take place.
  • When one must do such things as wash and
    sterilize laboratory glassware, this preparation
    can be a dull chore.
  • But when the experiment deals with the behavior
    of molecules, atoms or subatomic particles, the
    experimental setting becomes interesting in its
    own right. Such experiments often require an
    environment of consummate orderliness a high
    vacuum.
  • C.L. Stong, Scientific American, 1960

6
How Much Vacuum is Needed?
  • One mans vacuum is another mans sewer.
  • Norman Milleron, 1970

7
A Plumbers History of Vacuum
8
Making, Measuring Using Vacuum
9
Vacuum the Amateur Scientist
  • Technique
  • Homemade vacuum pumps and some of the things that
    can be done
  • with them, March 1960
  • Working in a Vacuum
  • October 1996
  • Much Ado about Nothing (including Bruce Kendalls
    Pirani gauge)
  • November 1996
  • Pressure Difference/Reduced Pressure
  • Wind Tunnel that Achieves Supersonic Speeds with
    a Vacuum System
  • October 1966
  • Apparatus for Simulating High Altitudes
  • September 1965 and April 1998

10
Vacuum the Amateur Scientist
  • Enabled by Increased Mean Free Path (Beams)
  • Aluminizing Equipment
  • August 1935, January 1939, July/August 1937
  • Cyclotron Built by a Group of Bold High School
    Boys
  • September 1953
  • How High School Students Constructed a b -ray
    Spectrometer
  • September 1958
  • Potential Drop Accelerators
  • January 1959, August 1971
  • High School Physics Club Builds Electron
    Microscopes
  • September 1973

11
Vacuum the Amateur Scientist
  • Vapor Pressure
  • How to Make an Isoteniscope an Apparatus for
    Measuring the Boiling
  • Point of Fluids
  • December 1970
  • Plasma/Glow Discharge Vapor Pressure
  • How to Generate Free Radicals and Collect them
    for Analysis
  • March July 1963

12
Vacuum the Amateur Scientist
  • Plasma/Glow Discharge
  • How to Sputter Thin Films of Metal onto Glass and
    Experiment with them
  • October 1967
  • Discharges at Reduced Pressure (various articles)
  • February 1956, February 1958, August 1966
  • Inexpensive and Safe Method for the Generation of
    X-Rays
  • July 1956
  • Gas Lasers (various articles)
  • September 1964, February 1969, September 1971,
    June 1974,
  • October 1980, April 1990
  • Cosmic Ray Telescope (G-M coincidence counter)
  • February 2001

13
Evolution of an Amateurs Vacuum System (35 years
of scrounging)
14
The Inspiration
John Strong Roger Haywards depiction of a
kinetic system for vacuum metallization Procedu
res in Experimental Physics 1938
15
Medium Vacuum - 1968 - 1980
  • First attempt at an integrated system. Mounted
    everything on/in a Grainger tool stand replaced
    the refrigerator compressor with a well worn
    Cenco Megavac belt drive pump.
  • 9 x 17 inch Pyrex cylindrical chamber with
    aluminum endplates
  • Copper plumbing fittings
  • Brass bellows valve (vent)
  • Homebrew thermocouple gauge
  • Homebrew fittings and feedthroughs
  • High vacuum diffusion pump mounted separately

16
High Vacuum - 1980 to 1995
  • Incorporated 2 diffusion pump (50s vintage)
  • A better mechanical pump
  • Another Grainger tool stand
  • Brass foreline valve
  • Ancient cold cathode gauge
  • Zeolite trap (optional)
  • Some standard fittings flanges

17
Current Primary System
HiVac Column
Med - Moderate HiVac Column
Plasma Focus
Added valving for roughing, capacitance manometer
for high accuracy pressure measurement,
filler tube when large glass chamber not
needed, turbo pump
Capacitor
18
Then Today
Above Segregated MedVac HiVac columns, copper
plumbing fittings. Right Integrated MedVac
HiVac columns, high use of standard
fittings, MFC for gas admittance, pressure
control.
19

Something Simpler
  • A simple vacuum pumping system for
  • basic experiments and teaching. Includes
  • refrigeration service pump, manifold made
  • of brass plumbing fittings, vent valve, gas
  • inlet needle valve, bourdon gauge and
  • separable polycarbonate bell jar.
  • Several of these have been made for high
  • school teachers, distributed via the AVS.

20
Rolling your Own
21
Materials Selection
  • Generally the amateur vacuumist will be working
    in the pressure range
  • over 10-5 Torr and will not be excessively
    concerned with small levels of
  • contamination
  • Copper plumbing fittings with solder connections
  • Tin-silver soft solder (remove flux residue)
  • O-ring/elastomeric seals
  • Limited use of polymers (Delrin, nylon, acrylic,
    vinyl tubing, etc.)
  • Glass (borosilicate preferred)
  • Stainless steel, aluminum and other low vapor
    pressure metals. Try to avoid brass, zinc, etc.
    especially in higher temperature applications and
    be wary of cast metals.
  • Avoid greases except for sliding seals
  • Generally avoid threaded pipe fittings but if
    used, seal the threads with 5-minute clear epoxy

22
Getting Materials
  • Several things have made the assembly of a vacuum
    system much
  • easier now than was the case 20 or more years
    ago
  • Wide use of vacuum in industry
  • Standardized components (fittings, flanges, etc.)
  • Great access to surplus sellers (e.g. eBay)
  • Information resources, support networks, internet

23
Tools
  • Standard hand tools for metal working
  • Plumbers torch for soldering light brazing
  • Drill press
  • Small metal lathe
  • Small milling machine highly desirable

24
Get Friendly with a Good Technical Glassblower
Wayne Martin MM Glassblowing Nashua, NH
25
Safety
  • Implosion (including loose things getting sucked
    in)
  • Electrical shock
  • Radiation (typically x-rays associated with high
    voltage/low pressure discharges)
  • Toxic and reactive chemicals
  • Pump exhaust vapors
  • Reaction by-products
  • Materials used in experiments
  • Residue left on surplus treasures

26
A Sampling of Amateur Vacuum Projects
27
Refurbishing a Relic Evaporator
John Moon and Alan Ward of Sudbury, Ontario
28
Small Plasma Gun - 3kJ
29
Thompson e/m Apparatus
30
Chris Fryes TEM
Scratch built, based on the RCA EMU series design
31
Richard Hulls Fusor Projects
The Open Source Fusor Research Consortium
www.fusor.net
32
Micro Freeze Dryer
33
Hypobaric Chamber for Biological Studies
34
G. Schmermunds Sorption Pumped X-Ray Tube
Bake zeolite filled bulb at 350º C attach to
x-ray tube Open stopcock and immerse bulb in
liquid nitrogen Apply voltage to electrodes,
close stopcock when discharge goes dark.
35
Greg Koneskys Arc Reactor for Synthesizing
Fullerines
  • Carbon arc operated at 100-300 Torr in helium
    atmosphere. Chamber
  • includes linear motion feedthrough to control rod
    separation and water
  • cooled collecting surface. Fullerines are
    concentrated from the soot using
  • a solvent wash or a Soxhlet extractor. Some other
    byproducts are formed,
  • perhaps carbolites.

36
Vacuum Gauges
Quartz Tuning Fork
Langmuirs Viscosity Gauge 1913
  • A potentially fruitful area for the amateur
  • Controller electronics for commercial sensors
  • Enhancements to cold cathode gauges
  • New life for forgotten designs

37
Saddle Field Ion/Atom Source
Gas Inlet
Anode Rods
Charged particle oscillator Operating Range
lt10-2 Torr No magnetic field Applications Ion
milling Ion beam processes Sample thinning
(TEM) DLC film deposition Reactive
Etching Pressure gauge
38
Gel Candle Debubbling
39
Resources for the Amateur
  • American Vacuum Society (AVS) www.avs.org
  • Publishes Journal of Vacuum Science Technology
    (JVSTA, JVSTB),
  • various educational monographs, AVS Classics
    books, etc.
  • Review of Scientific Instruments Pricey but
    limited open access is
  • starting in 2005
  • Society of Vacuum Coaters (SVC) www.svc.org
  • On line educational guides and Don Mattox
    Foundations of Vacuum
  • Coating Technology (66 page Acrobat file)
  • Vacuum Technology Coating (Industry Magazine)
    www.vactechmag.com
  • Excellent up-to-date information and free if you
    can make it through the
  • subscription form.
  • Institute of Physics www.iop.org
  • All articles are open access for 30 days from
    date of publication
  • Patents excellent grist for vacuum projects. All
    US patents are online via

40
199
  • Print journal started in 1992 as a quarterly for
    hobbyists and educators. Contributors range from
    beginners to professionals.
  • Temporary suspension during Vol 10 (2001)
  • Resuming publication in January 2005
  • Years 1-5 available as a compilation subsequent
    years as individual issues
  • Web site (www.belljar.net) contains on-line
    articles, tutorials and other features Discussion
    forum starting in early 2005
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