Airbus & LENR : "The Challenge"

Papp first design used water with a chlorine additive. It worked well but the water was hard on the inside of the engine. so Papp converted his process to use noble gas. R. Mills is using this same method in the Suncell where he uses water and copper to produce the reaction activated by a low voltage electric arc.

Papp used radium as the alpha particle source. They say he had a bottle of radium that he brought into the country from Europe buried in his backyard.

Papp produced a pressure pulse to push a piston. This is what Holmlid produces in his reaction. Leif produces a shock wave of nanoparticle fragments. In the Holmlid reaction like the Papp reaction, energy is not thermalized. Papp did the same thing except the particle fragments came from noble gas nanoparticles.

Quote from Longview

Again, is there a good link to a credible-to-you description of the Papp engine?

I saw a garage experimenter from Australia or New Zealand present a video on Youtube of a simple device that seemed worked, but I can't find the link. Russ Gries has attempted to build a so-called "popper," without success, if I recall, but I believe the general design will be similar to a working prototype [1]. (I suspect Gries was focusing on the gas mixture and on a magnetic field and didn't use a suitable alpha emitter.) Bob Rohner of the Rohner Group has been working on a demonstration "popper" which provides a simple demo and which Michael McKubre, a researcher involved in LENR at Stanford Research International, seems to think was legit [2]. If you ignore Feynman's claim of a hoax, you can see Bob and Tom Rohner testing and running a working engine for Josef Papp in a series of videos on Youtube starting with [3].

Unfortunately I cannot provide a link to a simple description that I know for sure to work, but Rus Gries's videos might be a good place to start.

[1] http://bit.ly/1kodAf7
[2] http://bit.ly/1jStDBt
[3] http://bit.ly/1GoFvp4

(LENR Forum insists on inlining the videos into this post, so I'm running the links through bit.ly.)

Quote from Longview

Thorium sounds like a good candidate. Are there lighter weight alpha emitters that might give much higher output to mass ratio for such application?. Of course it would have to be an alpha emitter with relatively long natural half life, otherwise it would be exhausted too fast for long endurance power output.

As you suggest, I suspect there's going to be a tradeoff that is made between potential thrust and how long the alpha emitter lasts. Most of the alpha emitters are heavier isotopes. Alpha decay is not an all-or-nothing thing, and if there is a way to induce activity, it's possible that some lighter elements that appear to be stable are in fact only "quasi-stable" and that activity can be induced in these under suitable conditions (this possibility is discussed in [1]).

Quote from Longview

Is there other evidence of laser stimulation of alpha decay other than say Letts / Hagelstein?... it is a fascinating idea to me.

The Letts-Hagelstein paper is one of a number of experiments that lend themselves to an interpretation of "LENR-as-induced-decay." Think of any LENR experiment that shows a correlation between helium and heat, for example. Nonetheless I am open to there being several different things going on in LENR, all of which have escaped scientific scrutiny up to now, just because of the controversy surrounding the subject.

[1] http://bit.ly/1MSS90U