Cosmic Radiation

On Tuesday, September 23, 2003, at 12:07 AM, Andy Goddard wrote:

> Al wrote:
>
>> For radiation protect similar to Earth you need twice the mass of the
>> atmosphere per unit surface area. You need 2x since the Earth blocks
>> almost all cosmic radiation coming from below so the dosage coming
>> from
>> any one direction needs to be cut in half.
>
> Ummm...if I'm on the inside surface of a cylinder, I can presume that
> the
> stuff "above" my local horizon is similar/greater in density than that
> which is below my feet, so surely the minimum thickness that's
> important
> here is the cylinder materials?
>
> Which, if I take a realistic atmospheric scale height (8.4km) and
> density
> (1.225 kg/m3), means I only need 10 tonnes of "stuff" per square metre
> for
> decent protection. Say 4m of concrete, 10m of ice...

I come up with (approximately) the same number.

>
> Regards,
>
> Andy G
>

Space tourism could be our ticket to the stars. Save your pennies,
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Al Globus
CSC at NASA Ames Research Center
http://www.nas.nasa.gov/~globus/home.html

Views expressed in this email are only my opinions and are not the
position of any organization I'm familiar with.