How can superconductors be used to protect spaceships from radiation in space?

[John d Marano]

This might be another silly question but here it goes;

I was reading how " A superconductor excludes the lines of magnetic force" http://www.aip.org/history/mod/superconductivity/01.html and I'm wondering if a giant superconducting magnetic field could help protect spaceships/space stations by deflecting charged particles? It's not a totally impractical question considering how cold space is it shouldn't be hard to maintain a large superconductor . . .Regards,
JDM

 

[OmCheeto]

This might be another silly question but here it goes;

I was reading how " A superconductor excludes the lines of magnetic force" http://www.aip.org/history/mod/superconductivity/01.html and I'm wondering if a giant superconducting magnetic field could help protect spaceships/space stations by deflecting charged particles? It's not a totally impractical question considering how cold space is it shouldn't be hard to maintain a large superconductor . . .Regards,
JDM

(bolding mine)

I think that's what caught me off guard, the first time I read it, many years ago.
It has since been revised:

The Meissner effect is the expulsion of a magnetic field from a superconductor during its transition to the superconducting state.

 

[Drakkith]

...and I'm wondering if a giant superconducting magnetic field could help protect spaceships/space stations by deflecting charged particles? It's not a totally impractical question considering how cold space is it shouldn't be hard to maintain a large superconductor . . .

That's a good question. Since the field is so small in size (compared to the Earth's field), it would probably have to be very powerful to have a noticeable impact on relativistic charged particles. Unfortunately I don't know any details.

 

[John d Marano]

That's a good question. Since the field is so small in size (compared to the Earth's field), it would probably have to be very powerful to have a noticeable impact on relativistic charged particles. Unfortunately I don't know any details.

Can't sleep tonight [again] so I'll wonder aloud;

If superconducting fields can deflect relativistic charged particles I wonder if a funnel shaped superconductor could channel those particles to fuel a solar sail . . .

JDM

 

[Drakkith]

Can't sleep tonight [again] so I'll wonder aloud;

If superconducting fields can deflect relativistic charged particles I wonder if a funnel shaped superconductor could channel those particles to fuel a solar sail . . .

JDM

Solar sails don't work off of charged particles. Besides, relativistic particles tend to go through things rather than simply impact and accelerate them. This tends to damage the material as well.

 

[OmCheeto]

I just finished reading a paper on this problem:
RADIATION HAZARD OF RELATIVISTIC INTERSTELLAR FLIGHT
by Oleg G. Semyonov

He lists some very good ideas:
Water, aluminum, titanium, and magnetic shielding.
The magnetic shield requires an electron stripper to be effective.

His last line seems hopeful:

Nevertheless, the shielding of relativistic starships from hard ionizing radiation produced by interstellar gas and cosmic rays does not seem to be far beyond existing technology.

His graph "b" on page 4 is interesting. With no shielding, at v = 0.1c, the radiation level is 90 REM/sec. Which from my memory, yields an LD-50 in only 5 seconds!

Hmmm...
0.1c = 30,000,000 m/sec
vessel radius = 5 m
vessel frontal area = π*10² = 78.5 m²
interstellar composition(from Oleg's paper) = 89% hydrogen + 10% helium + 1% other
interstellar density = 2E5 atoms/m³
hydrogen to deal with = 4.71E14 atoms/sec
mass of hydrogen atom = 1.66E-27 kg
Just calculating for the hydrogen, we get 0.000000000000782 kg collected or deflected per second.
Doesn't sound too difficult.

I do like the idea of collecting the hydrogen though.
Someone should figure out what the propulsive effect would be if we used particle accelerators to use them as thrust material, at say, 0.99c.
It seems such a waste to just throw things away.
But then the ship would accelerate to relativistically significant speeds, and then things would get way over my head.
Never mind.

hmmm...
γ = 1/√(1-v^2/c^2) = 7.09 @ 0.99c
mass of vehicle = 320000 kg (10 x a Greyhound bus. We're going to need a small nuclear reactor)
KE of hydrogen propellant = (γ-1)*mc^2 = 429,000 joules
Δv of vessel per second = √(2*ke/m) = 1.64 m/s
Time to accelerate to 0.2c = 7 months.
yup. Way over my head.