Re: Langston Field
There are problems with the Langston Field. It seems to be quite complicated.
Pournelle only really detailed it's function in his co-authored The Mote in God's Eye (with Larry Niven). Most of the rest of the time, it just seemed a defense field with an interesting failure effect.
However, in Mote we discover that it's semi-physically permeable. A human falls into the MacArthur's field and sticks there; he has to be pulled out by a search and rescue team. Later, a boarding team rams a pinnace through the ship's field to crash aboard, and suffer only a moment of extreme cold; similarly, three lifeboats are shot out of the field without any negative problems.
However, Torpedoes (which are simply powerful nuclear missiles) detonate on contact with the field, someimes causing pin-point burn throughs, i.e. the field can be overloaded locally before the energy has a chance to disperse throughout the field. Not to mention the question of why the torpedoes aren't just set to detonate inside the field and thus destroy the ship.
Plus, the fact that larger Langston Fields are more powerful than smaller ones due to having more area to radiate excess energy away with. The Moties exploit this feature with their expanding Langston Fields.
So, if you want a Langston Field you're not talking a simple build. I'm not going to have much free time until monday, but I might try and build one then.