I went back to the article to read it more carefully. Not only had I skimmed it the first time, for some reason I thought it was only two pages long when in fact it was a dozen!
http://www.infinite-energy.com/images/pdfs/RosenblumIE17.pdf
With this larger context I've learned some things from the article itself. One is the type of hydrino production technique. This was largely a gas / vapour cell (although there is some plasma), contained in a thick stainless steel cylindrical vessel, with the gas kept at near vacuum, something like 10e-3 atmospheres. The reaction volume must be kept hot in order for potassium (vapour phase) to be doubly ionized, in order to have the correct energy to serve as a hydrino catalyst.
Temperature of the outer skin of the vessel would reach around 750 C. In other words, the context of power and temperature regards the outer surface of the stainless steel. So I've concluded that Mill's use of the term 'power density' was surface power density, rather than volumetric power density. Just like the Sun has the volumetric power density of a composite heap but vast surface power density, so with this reaction vessel. With the inside of the vessel being near vacuum, there is no way Mills could be referring to volumetric power density imo.
Also, even the word 'continuous' means something different here. With the Suncell, continuous means that the ignitions are close enough together to appear as a continuous reaction. For example, a short BLP video at
https://www.youtube.com/watch?v=NfGgHD8e9sM
shows a pretty continuous operation.
But with this gaseous cell from 1997, continuous was contrasted with 'batch'.
To explain: For testing the cell would be near vacuum, with potassium metal inside heated sufficiently to ionize to K+2. A small amount of H2 was added and the vessel sealed. The H2 was dissociated by contact with a hot tungsten plate, forming atomic H. This atomic H would over time drop to lower and lower hydrino states, releasing huge amounts of energy per atom. So in a single batch run, the vessel would get hotter and hotter until the hydrogen was all used and the atomic hydrino had eventually all converted to dihydrino gas and hence would become nonreactive.
During a batch run the hydrino reactions themselves were continuous.
But in the context of a larger time frame it was still a single batch ; hydrogen was not being added. So in this larger time context it was not continuous.
But they were working on making it continuous. Here's an extract from page 28, my bold:
AR: Eventually, can the process run continuously?
RM: It can run continuously, yes. We've done that. Where you feed in new hydrogen.
AR: At a controlled rate, just as fast as it's needed?
RM: [Changed the subject!]
Yes, Mills didn't answer the question. Clearly they had not achieved this imo.
So this it seems to me is why this method of hydrino generation ultimately didn't work out. They couldn't successfully transition between from batch to continuous operation while simultaneously maintaining high enough temperatures.
Lowdown: It's settled in my mind, Mills gets a pass here. No doubt the skeptics here will protest. Oh well. The batch run experiments were validated as releasing heat energy far exceeding electrical energy input. That's good enough for me.
BTW that article makes for very good reading for both the beginner and the relatively experienced in matters of Dr. Mills and his GUTCP.
