From: johncobb@ut-emx.cc.utexas.edu (John W. Cobb)
Newsgroups: sci.physics
Subject: Re: ELECTRON HELIX : ITS POWER AND POSSIBLITIES
Date: 3 Sep 92 18:20:21 GMT
Reply-To: johncobb@ut-emx.cc.utexas.edu (John W. Cobb)
Organization: The University of Texas at Austin

Please put <CR>'s in your post, it makes for easier reading

In article <1992Sep1.121501.613@ualr.edu>, hdgarner@acs.harding.edu writes:
|>The purpose of this essay is to investigate the possibility of conforming
|> a stream of electrons into a helical path for the purpose of forming 
|>extremely powerful magnetic fields.  This helical path of electrons is 
|>what shall be referred to as the "electro|>n helix".  The basis for this 
|>research is the fact that a current-bearing wire wound into a helix forms
|> a magnetic field.  For most applications the wire is made of a metal 
|>such as copper which has a certain amount of resistance caused by the 
|>motion 
|>
|>
|>c
|>trons trying to pass through and transfer between the copper atoms.  
|>This motion causes friction which slows down the electrons and generates 
|>heat.  Because of this friction, there is a limit to how fast electrons 
|>can travel through an ordinary metal wire|> at room temperature before 
|>the wire melts from the heat generated by the friction.
|>A stream of electrons can attain extremely high speeds when they are 
|>free from the friction that occurs when they are confined to a metal 
|>wire.  My theory is that a stream of electrons can be accelerated near 
|>the speed of light with a particle accelerator|> and then, with the use 
|>of magnetic fields, constrained into a helix in the same way as a metal 
|>wire is wound into a coil.  This procedure will serve to convert a large
|>amount of electric energy into a large amount of magnetic energy.  The 
|>major diff
|>
There is one big fly in the ointment here. Your goal is to use this stream
of electrons to generate a magnetic field through Ampere's Law -no? Well
In order to get the electrons to move in a helix, you need an "External
field" Now each electron will respond to the cominbed effect of the
external field AND the magnetic field caused by the other moving electrons.
Now if you work out the signs, you will find that the electrons create a
"self magnetic field" that is pointed in the opposite direction to the
externally opposed magnetic field. Thus, when you start the electrons in
a helix, they will generate a field that opposes the external field, so
you will need to ramp up the external field or else the elctrons will fly
off into other orbits. So in the final analysis, you are better off just
using whatever was generating the external field in the first place, reverse
its current and you will get a larger magnetic field (for a given external
source) than is ever possible with the "electron helix" attachment. The basic
problem here is often stated as: gyrating electrons are diamagnetic with a
coefficient less than 1.

Now another idea is that you could take a superconductor while it is in
a normal state and put it in an external field. Then cool the superconductor
past its transition. The transition will cause currents to flow in the SC
coil. Now turn off the external field and you will have trapped the magnetic
field. Thus you have an energy STORAGE mechanism.

Also note, even if you get a really strong field, it won't do work for
you directly. The Lorentz force acts perpendicular to the velocity so 
a steady magnetic field will not accelerate anything (in the sense of
increasing its energy). It will only change the direction of the momentum
vector. [Now here's an easy puzzler: how do particle colliders like the
Tevatron, NSCL, or the SSC accelerate the particles, if not by steady
magnetic fields?]

Finally, I would caution you to be careful not to simply plug in numbers
willy-nilly without thinking about them. I seriously doubt that you
actually have over 20 significant digits in these numbers. Where do you get 
the number for the diameter of the electron that you use? This is 10,000 times 
smaller than the size on the electron in the hydrogen atom. In general the 
size of an electron is a function of its momentum for free electrons like you
are talking about. In fact the limit in "packing" these electrons together
is due to electrostaic repulsion. Take a while a figure out how much energy
will be required to assemble this 1 meter helix of pure electrons. You are
talking about an enourmous amount of energy just to assemble this
arrangement, not to mention the stresses involved in maintaining it.

I don't mean to be a bah-humbugger about an idea that popped into your
head. All ideas are new the first time you hear them. I jus tthink that
this one needs a great deal of "tweeking" before you will get it launched.
If you are really interested in following this further, let me suggest 
that you look toward the field of "one component plasmas". The idea is
that you confine a set of many like charged particles by clever choices
of electric and magnetic fields. These are sometimes similar to single
atom traps except that they are designed to study many-body problems. A
good place to start would be Ron Davidson's <Physics of Non-Neutral
Plasmas> published in 1990 By Addison wesley as Volume 81 in their
"Frontiers in Physics" series. There is some neat physics in this
sub-discipline. For instance, have you ever wondered what is the crystal
structure of pure electrons in a solenoidal magnetic field? [Okay
well maybe not, but you can find some neat wierdness here, in my mind not
unlike the delightful surprises that pop out of condensed matter theory
with things like superfluidity, etc.]

john w. cobb