[ExI] Why space tech isn't cutting edge

[spike]

-----Original Message-----
From: extropy-chat-bounces at lists.extropy.org
[mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of Adrian Tymes
Sent: Saturday, November 24, 2012 10:47 AM
To: ExI chat list
Subject: Re: [ExI] Why space tech isn't cutting edge

On Sat, Nov 24, 2012 at 10:18 AM, spike <spike66 at att.net> wrote:
>>... So we get this shower of secondary particles that hit the 
> microprocessor, and we know by Maxwell's equations an incoming charged 
> particle creates an EM field which in some rare cases can flip a bit

>...So, the problem with the secondaries is mainly that they are charged?

>...Lead or tungsten around magnetic fields.

>...First layer: a dense material to make as certain as practical that no
cosmic rays will penetrate, but will instead create secondaries for the
second layer to deal with.  If possible, multiple layers of crystal instead
of one single crystal to maximize coverage, and minimize gaps in the
molecular structure that rays can get through.

>...Second layer: multiple layers of magnets, again arranged in layers to
minimize straight paths through.  Make these magnets strong enough to suck
up or deflect charged secondary particles.  You don't have to stop them,
just steer them away from the CPU inside.

>...What problems do you see with this?
_______________________________________________

>From what I understand, the cosmic particle goes all the way through the
shield, then the spray (we used to call it a spall cone) is ionized material
from the back surface of the shield.  The front surface is nearly irrelevant
because the shield itself stops the secondary particles that are generated
from the particle's path, but the back surface gets you.  Of course with
sufficiently thick shielding, you could physically stop the particle and
everything it generates.  

Consider variations, such as a proton-electron pair being part of the spall
cone, which would be not deflected by a magnetic field, since it is neutral
as a pair, but ionizes upon impact with the surface of the processor.  Or
another problem I can imagine is that the magnetic field would deflect the
electrons only, since they are light, but not the protons, so that a shower
of protons only would give your gate a net positive charge.  Another
possibility is that the electrons in the spall cone fail to penetrate the
surface of the processor but the protons go blasting on in.  In both cases,
that would cause your NPN junctions to go temporarily short and your PNP
junctions to go temporarily open.

I hope you come up with a solution to that cosmic ray problem.  We are
cheering wildly for you Adrian.

spike