Re: Lasers and Scoops

[T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)]

>In addition to my other questions, this one about our ionizing laser for a 
>ramscoop is troubling.  How much power will it take to effectively cover an 
>area of space, perpendicular to the direction of the ship, with a laser 
>blanket beam that is strong enough to ionize iron?  If the numbers are too 
>obscene for sensitive readers, how about for hydrogen?

Yeah, sound really troubling isn't it? I pointed that out once, even not so
long ago a described what a maser beaming array would look like. I also
pointed out the we probably wouldn't need any shielding anymore because all
debris in our way would have been blasted away long before we would arrive.
I should mention though that this would only be true for the starting phase,
where the beam is still enough compact.

The numbers you are asking about, do depend on:
- the weight of the ship
- the final velocity
- the fading of the beam
- the accuracy of directing the beam
- the size of the receiver on the ship
- the velocity of the beam (c for EM-radiation, ? for Hydrogen)

Shortly said we don't know most of these factors accurately
(understatement), so we can only calculate minimum numbers. Keep in mind
that we are talking about diametres so things have the tendency to behave
quadratic instead of linear. I think that at best we can assume an
efficiency of 10%.

>By the way, I already know that shining your beams ahead of the ship like a 
>flashlight won't work.  I though that we could run the lasers through some 
>mirror aparatus.  Those mirrors would diverge and reflect the beam to shine 
>radially from the ship's bow in all directions perpendicular to the ship's 
>direction.  It would be like an ionizing blanket.
>
>Aren't there more efficient ways to ionize something besides use of lasers. 

No, only EM-radiation can do the trick. Maybe in the far futere there will
be other methods but not not.

Tim