Reply To: NIMBY FUD

[asymmetric_implosion]

Why stop at a billion? What distribution are you assuming to calculate your 1 in 14,000 chance of having 5 shots in a row that are within 3%? I think you will find that literature suggests a non-normal (non-Gaussian) distribution of radiation yield from a plasma focus. My concern is you don’t know the distribution of your radiation yield yet so claiming that 5 shots is statistically significant seems premature. In my way of thinking (engineer not physicist), each time you fire a shot you are sample the machine’s inherent distribution at a fixed set of conditions. You need to sample the distribution many times before you have confidence in it.

I’m not trying to say that the result is not exciting, but it is not unique. I appreciate that the typical standard deviation in most PF devices is ~ 50% (my PF is 46-53% depending on conditions) and you have demonstrated far better than most, but not all. Ahmed et al (doi:10.1088/0741-3335/48/6/003) showed 5% a few years ago in 10 shots using alpha particle pre-ionization. I believe your combination of the cathode near insulator and initial magnetic field are the reason for this. It is something that many others have not adopted yet.

I also appreciate the problems you’ve had with the pulse power but a reliable 1 MA drive that is demonstrated to operate at 1 Hz all day long at 100 kV costs about $5M. The electrodes and other components can’t cost more than $1M. Look up the linear transformer driver papers by Sandia National Lab. The LTD has rise times up to 800 ns. It seems that would go a long way to solving your pulse power problems in the next few years. Just my opinion but $6M seems better than $30M. Best of luck in the upcoming campaigns. I look forward to a paper on the statistical significance of the data later this year.