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Do-It-Yourself Ion
Trapping
Wolfgang
Paul and Hans
Dehmelt received the Nobel Prize for Physics in 1989 for developing ion
trapping technieques, and you can build your own ion traps to levitate
charged particles in air.
The
photograph on the right shows a collection of 25-micron-diameter
particles trapped in a loop earring. Additional pictures below show
traps made from various buckles and key rings. Traps like these are
easy to make and fun to use.
What you need:
>>
A high-voltage transformer, capable of supplying at least
3kV AC at
50-60 Hz, and preferably 110 volts to 6 kV. Suppliers can be difficult
to locate, but they are out there. Prices are also higher than one
might like.
>> A Variac to drive the transformer, such as this one.
>>
Current-limiting resistors, for safety. We use 10 MOhm, 10 Watt
resistors. You can buy them from your favorite electronics supplier
(Mouser, Digikey, etc.).
>>
Some particles to trap; we recommend Lycopodium club moss spores, as
they are cheap and harmless. They are available online under the name
"Dragon's Breath", ane you can purchase some from Amazon, eBay, or other suppliers.
>>
A laser pointer to illuminate the particles, with a lens to expand the
laser beam to a diameter of about 1 cm. The particles are quite
difficult to see without laser illumination.
>> An electronics chassis.
The necessary know-how is supplied in the documentation below. Good luck!
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Written
Documentation - Ion Trapping Demo Kit
1. Improved Microparticle Electrodynamic Ion Traps for Physics Teaching
This paper describes ion trapping physics
and many experimental tricks to make terrific microparticle ion traps.
2. How to Construct a Microparticle Ion Trap
A mathematics-free (almost)
description of ion trapping
3. Physics
of electrodynamic ion traps - A qualitative description
A mathematics-free (almost)
description of ion trapping
4. Particle dynamics in damped nonlinear quadrupole ion traps
The origin of extended orbits and the "trapnado" phenomenon
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Video
Documentation - Ion Trapping Demo Kit
Coming Soon .... See also our Electrodynamic Ion Traps experiment.
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Photo
Gallery - Ion Trapping Demo Kit
These ion traps were
all made with ths kit, using key rings, buckles, etc. The traps
are all interchangable since they are held in place (and powered) using
a single alligator clip The trap above is made from a
diamond-shaped earring. The particles were illuminated with a
green laser, and some of the images were modified (using PaintShopPro)
to give different colors.
   
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