Lead! (the heavy stuff)

[graham-xrf]

Sure you can turn it. As said above, it's soft and gummy. High rake tools (like for cutting plastic) should work well.

This gives me hope. So would that be 8° or 10° instead of standard 5° ?

 

[JimDawson]

This gives me hope. So would that be 8° or 10° instead of standard 5° ?

Good question. I would start grinding a HSS tool until it did what I wanted. Try it, and if it doesn't cut right, then grind a little more. If you want to use carbide inserts, then one for aluminum should work well. The rake angle at the cutting edge on those is about like a knife edge.

 

[NC Rick]

If it makes it more machining-friendly, then sure, the heavy lead content would work, if the aim was only to stop the radiation getting through the shield into where it was not wanted. This shield has also not to contaminate space with signatures of metals in the lead.

Here the attempt is to get the radiation to identify metals, and that needs that "quiet zone" shielded by lead. We know the energy is not high enough to provoke anything from the main signature for lead itself, other than a couple of recognizable low energy markers.
If we mix other stuff in the lead, it introduces atoms that will respond, so making signals competing with the responses from the alloys we are trying to identify. At least with pure lead, when the energy enters it, it pretty much gets stopped, absorbed, and turned into (a tiny amount) of heat.

If the shape can't be turned, then maybe we should go for a little casting.
As @Bi11Hudson has suggested, the idea of a casting that we can hand-ream to finish up seems to have potential.

Way above my pay grade. But very cool!

 

[graham-xrf]

Way above my pay grade. But very cool!

To be honest, a good deal of it started out way above mine. I never thought I would get this far into this project. The "xrf" in my HM ID was a complete coincidence, it alluding to my having retired from satellite RF engineering. We who are between us designing this thing are doing it all in the open in this forum, mistakes and all! Having to machine up something in lead is one of the challenges. Plastics too!

Luckily we discovered there are HM members who know a whole lot about radiation physics!