Thanks for the questions Ecco
As far as I understand the reaction can also occur spontaneously, without laser application, provided that enough ultra-dense hydrogen is generated with a hydrogen flux through the catalyst heated preferably in the 200-650°C range. Furthermore, in "Spontaneous ejection of high-energy particles from ultra-dense deuterium D(0)" it's suggested that it doesn't take much time for this process to occur. Here's an excerpt from the paywalled paper:
[...] At the start of a run with D2 gas admission into the apparatus, the signal out from the PMT with PS and glass converters is low as seen in the spectrum indicated “initial” in Fig. 3. After 1 h in that run, the signal increased a factor of 40 as shown by the higher curve in Fig. 3. [...]
This spontaneous process is occurring with the D(0) phase in place if you have D(1) normal Rydberg matter you would not observe it.
If one is to assume that in most low-temperature LENR experiments without nanosecond laser application performed throughout the years the same effect occurred, then the only thing one should be concerned with is attempting to produce as much ultra-dense hydrogen as possible. Eventually some sort of clearly anomalous reaction should be able to occur.
Yes in the end
Either way, shouldn't the transition from H2 to 2H and finally to the ultra-dense phase be quite exothermic?
H2 to 2H* is endothermic. 2H* to H(1) is not known but most likely little exothermic with reference to 2H*. H(1) to H(0) must have similar total energy otherwise they could not transform easily in to one another as Holmlid has observed.
EDIT: sveinol: more in detail, what would the heat of formation of H(0) be? I recall reading somewhere 630eV, but that seems a very high value given that it should be about 4.5eV for the formation of molecular hydrogen. At this level it would not be better than nuclear, but it would still be much better than chemical.
The 630eV energy is not formation energy of (H0) it is the repulsive electrostatic energy when the binding mechanism has been removed with the laser.
Greetings
Sveinn