Active Sheilding

Bill,

Response below:
From: bill t
To: spacesettlers@egroups.com
Sent: Sunday, December 24, 2000 1:55 PM
Subject: [spacesettlers] Re: Active Sheilding

You still have the problem of the X-Ray bath caused by all the
electrons hitting the metal grid.

Tom - But if the grid is a KM away, the reduction per inverse square law will be substantial. Modest shielding will still be necessary, and I am not arguing against passive shielding, but only that active shielding should be kept on the table and studied.

To do it properly you need a magnetic field to divert the electrons
from the grid. Once you have that the billions of volts you will have
to be dissappiate all that energy that gets converted to heat. So we
are again at the heat dissapiation problem.

Tom - This would require further analysis.

Anyway, there is a whole class of neutral particles that will be
totally unaffected by electromagnetic shields that could easily kill
everyone.

Tom - The only neutral particles I know of are neutrons, and they will have decayed long before arriving on site. Naturally, X and gamma rays must be shielded passively.

I'm still into the passive shields camp. It is a low maintanence
solution.

Bill

--- In spacesettlers@egroups.com, "Tom Tucker (Olympia)"
wrote:
> Bill,
>
> So, I take it you now agree that active shielding can be used to at
least deal with cosmic rays and positively charged ions from the sun?
By the way, we are talking about billions of volts, not millions since
I believe that cosmic rays have an energy equivalent to 30 billion EV.
>
> Now, lets proceed with dealing with those pesky electrons. Since
they have a relatively low mass and can be compelled to turn at very
sharp corners, we can use either an electric or magnetic field to
divert them.
>
> From a distance, a 1km diameter shell appears to be a point
charge. Instead of charging the exterior of the colony with the high
charge, lets charge instead a spherical wire grid surrounding the
colony. Electrons are attracted to the positively charged grid and
are neutralized or diverted, and positively charged nuclei are
repelled. Only problem remains to maintain the charge and
construction.
>
> Cheers,
>
> Tom
>
> From: bill t
> To: spacesettlers@egroups.com
> Sent: Saturday, December 23, 2000 2:18 PM
> Subject: [spacesettlers] Re: Active Sheilding
>
> If you are a million volt positive charge, every electron in the
> solarsystem will be attracted to you. When they hit the outer
shell
> they will have a million eV energy each. when a electron hits a
metal
> (the outer shell) it produces X-Rays. These X-Rays will be
directed
> towards the interior of the habitat. Thus you will have a constant
> X-Ray source inside the habitat.
>
> Finally, for every positive charged nuclei that gets thrown out of
the
> sun, there is at least one electron that has been dissaciated from
it.
>
> Bill
>
> --- In spacesettlers@egroups.com, "Tom Tucker (Olympia)"
> wrote:
> >
> > From: Ian Woollard
> > To: spacesettlers@egroups.com
> > Sent: Thursday, December 21, 2000 8:57 PM
> > Subject: Re: [spacesettlers] Active Sheilding
> >
> >
> > bill t wrote:
> >
> > > The main problem with Active Shielding...
> >
> > The main problem with active shielding is that it doesn't
> > work. Period.
> >
> > > You can arrange a magnetic field to deflect the electrons,
but
> I'm
> > > wondering what the weight of the material, and the power
> utilization
> > > is. All the power is heat that has to be radiated away. This
> means
> > > more radiators.
> >
> > Radiators aren't a problem. The problem is that people die
> > from radiation poisoning (10% chance of cancer per 5-10 years
> > if I remember correctly), caused by cosmic rays. Active
shielding
> > doesn't touch cosmic rays- they're waaaay too high energy. We
> > can't even produce rays that powerful in our particle
> > accelerators that are miles across and use whole power
> > stations to keep them running; active shielding
> > has absolutely no chance of even deflecting it,
> > and quite a lot of the particles aren't even charged
> > anyway.
> > Tom Tucker - Bill, cosmic rays are nuculi that have been
stripped
> of their electrons which makes them positively charged. Solar
flares
> are a storm of charged particles with the bulk also consisting of
> ionized nuculi. Both of these types of deadly radiation can be
> repelled by a positive high voltage charge. Since in space, there
is
> no place for a charge to arc or to drain from via ionization as
there
> is when in an atmosphere, one could perhaps build-up a charge of
> billions of volts which is comparable to that of cosmic rays and
in
> excess of that found in solar flares. The positive charge would
be
> maintained/generated by the use of an electron gun/accelerator
located
> a few KM from the space craft on the end of a conductive tether.
In
> space, we can generate much higher voltages than we can on earth.
> > Particle accelerators produce very heavy nuculi at hear the
> velocitiy of light, but this is not relevant to the electrostatic
> shielding under discussion here.
> > Proof of concept has yet to be attempted, but hypothetically,
it
> can be done.
> >
> > X-Rays from the sun and stars are a much smaller worry and
some
> light shielding would still be needed for these EMF for which
active
> shielding will be ineffective. How much would be needed? Need more
> data. Perhaps the few CM of steel that a "cruise ship type
habitat"
> would use would be sufficient?
> >
> > 6 foot of just about anything non radioactive works wonders.
> >
> > If a lunar mass driver is used that's not ridiculous.
> >
> > I worked out about $100/ft^2 ballpark. Getting some
> > near earth asteroids should be cheaper still (some
> > of them have delta-vs of tens of meters - yes that's
> > right meters not kilometers, per second.)
> >
> > Living in asteroids will be much cheaper. Shoring up the
> > inside of an asteriod you've mined out is pretty simple and
cheap
> > in microgravity.
> >
> > You get the outside for free pretty much. You don't have to
> > move anything anywhere, just tie the rubble down, smelt your
> > aluminium and sling up some big mirrors and put a sign outside
> > 'home sweet home'.
> >
> > > Just a Thought,
> > >
> > > Bill
> >
> >
> >
> >
> >
>

Response below:
From:
bill t
To:
spacesettlers@egroups.com
Sent:
Sunday, December 24, 2000 1:55 PM
Subject:
[spacesettlers] Re: Active Sheilding
You still have the problem of the X-Ray bath caused by all the
electrons hitting the metal grid.
Tom - But if the grid is a KM away, the reduction per inverse square law will be substantial. Modest shielding will still be necessary, and I am not arguing against passive shielding, but only that active shielding should be kept on the table and studied.
To do it properly you need a magnetic field to divert the electrons
from the grid. Once you have that the billions of volts you will have
to be dissappiate all that energy that gets converted to heat. So we
are again at the heat dissapiation problem.
Tom - This would require further analysis.
Anyway, there is a whole class of neutral particles that will be
totally unaffected by electromagnetic shields that could easily kill
everyone.

Tom - The only neutral particles I know of are neutrons, and they will have decayed long before arriving on site. Naturally, X and gamma rays must be shielded passively.
I'm still into the passive shields camp. It is a low maintanence
solution.
Bill
--- In spacesettlers@egroups.com, "Tom Tucker (Olympia)"
tntucker@c...> wrote:
> Bill,
>
> So, I take it you now agree that active shielding can be used to at
least deal with cosmic rays and positively charged ions from the sun?
By the way, we are talking about billions of volts, not millions since
I believe that cosmic rays have an energy equivalent to 30 billion EV.
>
> Now, lets proceed with dealing with those pesky electrons. Since
they have a relatively low mass and can be compelled to turn at very
sharp corners, we can use either an electric or magnetic field to
divert them.
>
> From a distance, a 1km diameter shell appears to be a point
charge. Instead of charging the exterior of the colony with the high
charge, lets charge instead a spherical wire grid surrounding the
colony. Electrons are attracted to the positively charged grid and
are neutralized or diverted, and positively charged nuclei are
repelled. Only problem remains to maintain the charge and
construction.
>
> Cheers,
>
> Tom
>
> ----- Original Message -----
> From: bill t
> To: spacesettlers@egroups.com
> Sent: Saturday, December 23, 2000 2:18 PM
> Subject: [spacesettlers] Re: Active Sheilding
>
> If you are a million volt positive charge, every electron in the
> solarsystem will be attracted to you. When they hit the outer
shell
> they will have a million eV energy each. when a electron hits a
metal
> (the outer shell) it produces X-Rays. These X-Rays will be
directed
> towards the interior of the habitat. Thus you will have a constant
> X-Ray source inside the habitat.
>
> Finally, for every positive charged nuclei that gets thrown out of
the
> sun, there is at least one electron that has been dissaciated from
it.
>
> Bill
>
> --- In spacesettlers@egroups.com, "Tom Tucker (Olympia)"
>
> >
> > ----- Original Message -----
> > From: Ian Woollard
> > To: spacesettlers@egroups.com
> > Sent: Thursday, December 21, 2000 8:57 PM
> > Subject: Re: [spacesettlers] Active Sheilding
> >
> >
> > bill t wrote:
> >
> > > The main problem with Active Shielding...
> >
> > The main problem with active shielding is that it doesn't
> > work. Period.
> >
> > > You can arrange a magnetic field to deflect the electrons,
but
> I'm
> > > wondering what the weight of the material, and the power
> utilization
> > > is. All the power is heat that has to be radiated away. This
> means
> > > more radiators.
> >
> > Radiators aren't a problem. The problem is that people die
> > from radiation poisoning (10% chance of cancer per 5-10 years
> > if I remember correctly), caused by cosmic rays. Active
shielding
> > doesn't touch cosmic rays- they're waaaay too high energy. We
> can't even produce rays that powerful in our particle
> > accelerators that are miles across and use whole power
> > stations to keep them running; active shielding
> > has absolutely no chance of even deflecting it,
> > and quite a lot of the particles aren't even charged
> > anyway.
> > Tom Tucker - Bill, cosmic rays are nuculi that have been
stripped
of their electrons which makes them positively charged. Solar
flares
> are a storm of charged particles with the bulk also consisting of
> ionized nuculi. Both of these types of deadly radiation can be
> repelled by a positive high voltage charge. Since in space, there
is
> no place for a charge to arc or to drain from via ionization as
there
> is when in an atmosphere, one could perhaps build-up a charge of
> billions of volts which is comparable to that of cosmic rays and
in
> excess of that found in solar flares. The positive charge would
be
> maintained/generated by the use of an electron gun/accelerator
located
> a few KM from the space craft on the end of a conductive tether.
In
> space, we can generate much higher voltages than we can on earth.
> > Particle accelerators produce very heavy nuculi at hear the
> velocitiy of light, but this is not relevant to the electrostatic
> shielding under discussion here.
> > Proof of concept has yet to be attempted, but hypothetically,
it
> can be done.
> >
> > X-Rays from the sun and stars are a much smaller worry and
some
> light shielding would still be needed for these EMF for which
active
> shielding will be ineffective. How much would be needed? Need more
> data. Perhaps the few CM of steel that a "cruise ship type
habitat"
> would use would be sufficient?
> >
> > 6 foot of just about anything non radioactive works wonders.
> >
> > If a lunar mass driver is used that's not ridiculous.
>
> > I worked out about $100/ft^2 ballpark. Getting some
> > near earth asteroids should be cheaper still (some
> > of them have delta-vs of tens of meters - yes that's
> > right meters not kilometers, per second.)
> >
> > Living in asteroids will be much cheaper. Shoring up the
> > inside of an asteriod you've mined out is pretty simple and
cheap