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Hobbyist vaccum system, suggestions for projects?

W

William J. Beaty

Jan 1, 1970
0
I just bought a "coater" at the UW surplus auction.
http://www.washington.edu/admin/surplus/LOT72A.jpg It's a
console with a 14" bell jar w/various vacuum feedthroughs,
all hooked to a diffusion pump, vacuum pump, pirani/penning
gauges, and a 100-amp 10V power supply. Looks almost totally
pristine. The big rubber gasket is all cracked, and it melted
itself onto the bell jar rim, so the thing probably sat in a store
room for a few years. I've yet to see if it runs the first time
plugged in.

My question: what would YOU do if you scored such a beast?

:)

I'll probably start out simple and make the world's largest
radiometer. A field-emission microscope would be cool (make
a phosphor screen, then erode a tungsten wire atomically-sharp
using acetylene torch or electrolysis.)

I've always wondered what hobby-science would be like in
low Earth orbit or on the moon. Stick your workbench in a
vacuum environment where incandescent bulbs need no glass (and
where the hot filaments generate an electron cloud, so custom
vacuum tubes can be made from light bulbs and bits of foil.)
Now I can finally try such things out. Why not take an old
tube-type table radio, break the glass envelopes off all the
tubes, then pump the whole thing down and see if I can still
get it to work? Same with an oscilloscope. Cut the electron
gun free and shine it on phosphor-coated glass. And if I can
manage to cast fluorescent shadows on a phosphor screen with
a wide, high-current e-beam, what will the SHADOW of a small
coil look like as I crank up the current in the coil? (or as
I charge the whole coil to pos or neg high voltage?) And I
wonder how easy it is to make a TEM out of soup cans and duct
tape?

Other than that, I can't think of anything good. :)

Has anyone here kept up with The Bell Jar newsletter? Were there
any cool projects there worth tracking down?


(((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))
William J. Beaty SCIENCE HOBBYIST website
[email protected] http://amasci.com
EE/programmer/sci-exhibits amateur science, hobby projects, sci fair
Seattle, WA 206-789-0775 unusual phenomena, tesla coils, weird sci
 
R

Richard Henry

Jan 1, 1970
0
William J. Beaty said:
I just bought a "coater" at the UW surplus auction.
http://www.washington.edu/admin/surplus/LOT72A.jpg It's a
console with a 14" bell jar w/various vacuum feedthroughs,
all hooked to a diffusion pump, vacuum pump, pirani/penning
gauges, and a 100-amp 10V power supply. Looks almost totally
pristine. The big rubber gasket is all cracked, and it melted
itself onto the bell jar rim, so the thing probably sat in a store
room for a few years. I've yet to see if it runs the first time
plugged in.

My question: what would YOU do if you scored such a beast?

:)

I'll probably start out simple and make the world's largest
radiometer. A field-emission microscope would be cool (make
a phosphor screen, then erode a tungsten wire atomically-sharp
using acetylene torch or electrolysis.)

I've always wondered what hobby-science would be like in
low Earth orbit or on the moon. Stick your workbench in a
vacuum environment where incandescent bulbs need no glass (and
where the hot filaments generate an electron cloud, so custom
vacuum tubes can be made from light bulbs and bits of foil.)

If it has no glass, why would you call it a bulb?
 
J

James Meyer

Jan 1, 1970
0
I just bought a "coater" at the UW surplus auction.
http://www.washington.edu/admin/surplus/LOT72A.jpg It's a
console with a 14" bell jar w/various vacuum feedthroughs,
all hooked to a diffusion pump, vacuum pump, pirani/penning
gauges, and a 100-amp 10V power supply. Looks almost totally
pristine. The big rubber gasket is all cracked, and it melted
itself onto the bell jar rim, so the thing probably sat in a store
room for a few years. I've yet to see if it runs the first time
plugged in.

My question: what would YOU do if you scored such a beast?
Use it to freeze-dry that guy that keeps claiming that Einstein was
wrong and that he can make FTL cables.

Jim "Add water to reconstitute." Meyer
 
U

Uncle Al

Jan 1, 1970
0
William J. Beaty said:
I just bought a "coater" at the UW surplus auction.
http://www.washington.edu/admin/surplus/LOT72A.jpg It's a
console with a 14" bell jar w/various vacuum feedthroughs,
all hooked to a diffusion pump, vacuum pump, pirani/penning
gauges, and a 100-amp 10V power supply. Looks almost totally
pristine. The big rubber gasket is all cracked, and it melted
itself onto the bell jar rim, so the thing probably sat in a store
room for a few years. I've yet to see if it runs the first time
plugged in.

My question: what would YOU do if you scored such a beast?

:)

What a fine toy! Be carful with the glass bell jar - implosion
hazard. No surface scratches!
I'll probably start out simple and make the world's largest
radiometer. A field-emission microscope would be cool (make
a phosphor screen, then erode a tungsten wire atomically-sharp
using acetylene torch or electrolysis.)

Electrolysis. It's in the literature.
I've always wondered what hobby-science would be like in
low Earth orbit or on the moon. Stick your workbench in a
vacuum environment where incandescent bulbs need no glass (and
where the hot filaments generate an electron cloud, so custom
vacuum tubes can be made from light bulbs and bits of foil.)

Lee de Forest ho!
Now I can finally try such things out. Why not take an old
tube-type table radio, break the glass envelopes off all the
tubes, then pump the whole thing down and see if I can still
get it to work?

The Group I oxide emission coating on the filaments is incredibly
sensitive to atmospheric contamination. A vacuum radio will put
NASA's stupid human tricks in space to shame. That's hometown
newspaper stuff!
Same with an oscilloscope. Cut the electron
gun free and shine it on phosphor-coated glass. And if I can
manage to cast fluorescent shadows on a phosphor screen with
a wide, high-current e-beam, what will the SHADOW of a small
coil look like as I crank up the current in the coil? (or as
I charge the whole coil to pos or neg high voltage?) And I
wonder how easy it is to make a TEM out of soup cans and duct
tape?

High voltage electrons aimed at a surface = bremsstrahlung. CRT faces
are thick leaded glass. Don't get a dose of soft x-rays.
Other than that, I can't think of anything good. :)

80% argon, 10% hydrogen, 1% methane + RF generator to strike a plasma
in ca. 200 torr - CVD diamond deposition. If you have an internal
densified graphite slab as one electrode you can sputter coat diamond
through a hydrogen plasma. Beware UV emission.

Buckeyballs and nanotubes in 200 torr helium from DC carbon arc
between densified graphite electrodes (Sears' buzz box). Hydrogen
should sputter diamond. The emitter electrode can be thin (cooled by
work function as electrons evaporate) but the electrode the electons
impact must be substantial - it rapidly erodes.

Your Christmas/Chanuka/Ramadan/Kwanzaa/Winter Solstice came early this
year!
 
S

S.M.Taylor

Jan 1, 1970
0
William said:
I just bought a "coater" at the UW surplus auction.
http://www.washington.edu/admin/surplus/LOT72A.jpg It's a
console with a 14" bell jar w/various vacuum feedthroughs,
all hooked to a diffusion pump, vacuum pump, pirani/penning
gauges, and a 100-amp 10V power supply. Looks almost totally
pristine. The big rubber gasket is all cracked, and it melted
itself onto the bell jar rim, so the thing probably sat in a store
room for a few years. I've yet to see if it runs the first time
plugged in.

My question: what would YOU do if you scored such a beast?

Go on, what did you pay for it ? I got one for 18" mirrors in the UK
last year for 150 GBP, 250 usd, just like yours.I'd like to still think
I got a bargain !

Steve
 
D

DarkMatter

Jan 1, 1970
0
Other than that, I can't think of anything good. :)


Sell the chamber to my company. How big is it?

Don't worry about the gasket.
 
D

DarkMatter

Jan 1, 1970
0
Use it to freeze-dry that guy that keeps claiming that Einstein was
wrong and that he can make FTL cables.

Jim "Add water to reconstitute." Meyer

Hahhaahhhah good one! Is that "Rod Speed"? What an ass he is.

He is a con artist, fully exposed.
 
K

klmok

Jan 1, 1970
0
I just bought a "coater" at the UW surplus auction.
http://www.washington.edu/admin/surplus/LOT72A.jpg It's a
console with a 14" bell jar w/various vacuum feedthroughs,
all hooked to a diffusion pump, vacuum pump, pirani/penning
gauges, and a 100-amp 10V power supply. Looks almost totally
pristine. The big rubber gasket is all cracked, and it melted
itself onto the bell jar rim, so the thing probably sat in a store
room for a few years. I've yet to see if it runs the first time
plugged in.

My question: what would YOU do if you scored such a beast?


I once wanted a lab size bell jar for jewelry casting work where a
vacuum to excavate the investment is an essential procedure. Got a
quote of more than CDN$1000 for just the bell jar. What you scored on
is probably worth at least $3 thou new. Besides jewelry work (never
got started on it) that vacuum system is probably very useful for
resin casting work as in making scale model parts.
 
M

Murray Arnow

Jan 1, 1970
0
Uncle Al said:
What a fine toy! Be carful with the glass bell jar - implosion
hazard. No surface scratches!
I'm jealous. It's the same kind of gear that got me through my thesis
(my apparatus had a few more more geegaws).
Electrolysis. It's in the literature.
If you are going after field emission with this sort of primitive
arrangement, you'll need a much higher-voltage power-supply -- kV range.

I don't know how much you know about electron lenses, but you'll have to
build one for the microscope. This can be a bit dicey. There's lots of
literature out there to fall back on.
Lee de Forest ho!


The Group I oxide emission coating on the filaments is incredibly
sensitive to atmospheric contamination. A vacuum radio will put
NASA's stupid human tricks in space to shame. That's hometown
newspaper stuff!
Uncle Al is right about coating contamination. An activated cathode (the
primary emitter is typically barium oxide) will readily form a poorly
emitting barium hydroxide when exposed to air.

The way to lessen the contamination is to keep the cathode-heater at a
reduced current, just enough to keep the cathode slightly war, whenever
you expose the cathode to the atmosphere. Eventually, the cathode will
die, but you can reclaim it by painting the the surface with barium
carbonate and re-activating.
High voltage electrons aimed at a surface = bremsstrahlung. CRT faces
are thick leaded glass. Don't get a dose of soft x-rays.
If William only uses the 10 volt supply, I don't think he has to worry
about any x-ray hazards. I don't know what kind of high-voltage currents
William plans to use, but he will see a great many interesting things in
the micro- and nano- amp ranges which also won't cause too much x-ray
concern.
80% argon, 10% hydrogen, 1% methane + RF generator to strike a plasma
in ca. 200 torr - CVD diamond deposition. If you have an internal
densified graphite slab as one electrode you can sputter coat diamond
through a hydrogen plasma. Beware UV emission.
UV hazard outside the bell jar?
Buckeyballs and nanotubes in 200 torr helium from DC carbon arc
between densified graphite electrodes (Sears' buzz box). Hydrogen
should sputter diamond. The emitter electrode can be thin (cooled by
work function as electrons evaporate) but the electrode the electons
impact must be substantial - it rapidly erodes.
Beware, sputtering experiments inside your new bell will leave
everything inside in less than pristine condition.
Your Christmas/Chanuka/Ramadan/Kwanzaa/Winter Solstice came early this
year!
William, you should try to get a copy of "Handbook of Materials and
Techniques for Vacuum Devices" by Walter H. Kohl. It is out of print,
but there are copies floating around. It is a mine of information for
operating a system like yours.

Good luck and have fun.
 
S

Stepan Novotill

Jan 1, 1970
0
You can expand styrofoam heads if you add a bit of heat as you pump
out the air. To shrink a styrofoam head you tie it to a rock and lower
it a hundread feet into the ocean off a canoe. I saw this done to a
styrofoam cup and it came out the size of a small shot glass.
 
P

Paul R. Mays

Jan 1, 1970
0
Stepan Novotill said:
You can expand styrofoam heads if you add a bit of heat as you pump
out the air. To shrink a styrofoam head you tie it to a rock and lower
it a hundread feet into the ocean off a canoe. I saw this done to a
styrofoam cup and it came out the size of a small shot glass.



Freeze drying herb in a vacuum for freshness....
 
P

Paul R. Mays

Jan 1, 1970
0
William J. Beaty said:
I just bought a "coater" at the UW surplus auction.
http://www.washington.edu/admin/surplus/LOT72A.jpg It's a
console with a 14" bell jar w/various vacuum feedthroughs,
all hooked to a diffusion pump, vacuum pump, pirani/penning
gauges, and a 100-amp 10V power supply. Looks almost totally
pristine. The big rubber gasket is all cracked, and it melted
itself onto the bell jar rim, so the thing probably sat in a store
room for a few years. I've yet to see if it runs the first time
plugged in.

My question: what would YOU do if you scored such a beast?


Http://Ripkaboroski.com/device5.jpg
Http://Ripkaboroski.com/device5b.jpg

Varification device for modification of quantum state
 
S

Steve Roberts

Jan 1, 1970
0
First thing, get rid of the Diff pump and get a used turbopump and/or
large ion pump. You wont miss the oil mist. Second get a huge rougher
pump, preferably direct drive rotary vane. on large chambers, the
pump[ing rate of the rougher and its ultimate vacuum are critical,
keep the vacuum connections short!

if I had a large chamber and room for it, I already have the the
rougher/turbo/270 L/sec ion pump for pumping laser tubes I'd:

1. vacuum evap my own transistors. even better yet, build a opamp.
even if the slew rate was only one volt per second and the offset is
huge, a home made functional opamp on a microscope slide would put
you into the record books.

2. coat my own mirrors, and coat amatuer astro mirrors to pay for
chamber upgrades.

3. a 10-20 litre volume of glowing neon has to be beautiful.

4. a low energy SEM, using backscatter or xray detector

5. look up the word omegatron, ie a tiny mass spec.

6. plasma cleaning/etching

7. hydrogen cleaning and vacuum brazing of small assemblies

8. mini linac.

9, worlds largest nixie!

10. a whole radio in one tube

11. a working home made crt

Steve Roberts
 
N

Nils Dalen

Jan 1, 1970
0
I just bought a "coater" at the UW surplus auction.
http://www.washington.edu/admin/surplus/LOT72A.jpg It's a
console with a 14" bell jar w/various vacuum feedthroughs,
all hooked to a diffusion pump, vacuum pump, pirani/penning
gauges, and a 100-amp 10V power supply. Looks almost totally
pristine. The big rubber gasket is all cracked, and it melted
itself onto the bell jar rim, so the thing probably sat in a store
room for a few years. I've yet to see if it runs the first time
plugged in.

My question: what would YOU do if you scored such a beast?

:)

1) check the Duniway stockroom catalogue for a new gasket
2) check the bottom of the diff pump and see of the old oil was burned
by a prior user
3) if (2) sandblast the diff pump
4) get new oil for the diff pump (duniway)
5) check pressure on the rough pump (put a gauge directly on the
pump). Make sure you can pull <50 Torr
6) if not (5) look for a rebuild kit for the rough pump
7) don't run the diff pump until you get a good rough pump and seal on
the bell jar.
8) do you need boats or wire for the evap source? Get these as well.

You could then always evap gold onto cheap silver jewelry (something
like earrings that won't get rubbed so much). Just be fairly sure
that the relationship isn't expected to last longer than the gold
coating....

Nils
 
U

Uncle Al

Jan 1, 1970
0
Stepan said:
You can expand styrofoam heads if you add a bit of heat as you pump
out the air. To shrink a styrofoam head you tie it to a rock and lower
it a hundread feet into the ocean off a canoe. I saw this done to a
styrofoam cup and it came out the size of a small shot glass.

100 feet is 3 atmospheres. That won't do much to any respectible
sytrofoam cup, PV=nRT. Between Catalina Island and the Southern
California coast the ocean plummets 2500-2700 feet deep. 75-80
atmospheres ought to do it. The usual demo is to attach foamed stuff
to the surface of a deep submersible and go down into an abyssal or
just the bottom of the Atlantic (2 miles) or the Pacific (3 miles).
Crunch.

If you are in the deep submersible, pray to the god of syntactic foam.
 
U

Uncle Al

Jan 1, 1970
0
Murray said:
[snip]
80% argon, 10% hydrogen, 1% methane + RF generator to strike a plasma
in ca. 200 torr - CVD diamond deposition. If you have an internal
densified graphite slab as one electrode you can sputter coat diamond
through a hydrogen plasma. Beware UV emission.
UV hazard outside the bell jar?

Any hot plasma is a not insubstantial UV source just from the temp.
The bell jar is most likely Pyrex and will be transparent into UV-B.
It is a very real eye and skin hazard.

I once worked near paired 1 kW microwave-pumped electrodeless mercury
discharge lamps. They were little suckers hardly the size of hot
dogs. We went around the thing in the dark with ZnS/Cu phosphor paper
checking for pinholes after the microwave field survey came up clean.
Engineers go in first!

"Do not look into laser beam with remaining eye." Even "safe" laser
pointers are nasty. Be conservative.

[snip]
 
M

Murray Arnow

Jan 1, 1970
0
Uncle Al said:
Any hot plasma is a not insubstantial UV source just from the temp.
The bell jar is most likely Pyrex and will be transparent into UV-B.
It is a very real eye and skin hazard.

I recall discussions about UV eye-hazard a few years back with people I
thought knowledgeable in the subject. There is little doubt about UV
being a skin hazard, but what was maintained was that the humors of eye
efficiently attenuated UV leaving the retina out of harms way. I don't
know if UV is known to be responsible for cataracts or turbidity in the
humors, though. Anyway, where the eyes are concerned it is always wise
to take precautions.
 
T

Tim Boescke

Jan 1, 1970
0
1. vacuum evap my own transistors. even better yet, build a opamp.
even if the slew rate was only one volt per second and the offset is
huge, a home made functional opamp on a microscope slide would put
you into the record books.

This reminds me of something. I wonder what kind of semiconductor
devices could be produced by a hobbyist using easily accessable
equipment and materials?

Of course there is a plethora of point contacts devices. I have
seen various reports on home made detectors using galena (mineral
or home made), ZnO, FeS2 etc.

Another interesting find was a Cu2O solar cell made from a heated
copper sheet and NaCl electrolyte.

Are there any more interesting devices you could make, being limited
to simple technologies? (Well, limiting maybe to atmospheric
tempering/annealing at most)

For example there were some papers about using Dip-Coating to
deposit doped ZnO/NiO Layers using acetates, annealing just
required moderate temperatures. Several groups even reported
working PN-Diodes and MISFETs. This looks like a promising route,
given that one would be able to prepare the precursors - which
should be possible for a hobbyist chemist.

How about building devices utilising electrochemistry? A
semiconductor/electrolyte diode should be comparably simple
or how about something akin a CHEM-MESFET? (CHEMFET without
dielectric insulator)

Any ideas for metal deposition? How about insulating layers?
Also photolithography should not be too far off, there are
lots of people making their own ~200um resolution PCBs at
home using contact aligment.
 
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