[KeithPickering]

Loved it. You inspired me to install LMMS, which I had never heard of before. 🙂

[KeithPickering]

The final version of the DPF bibliography is now available (240 references since 2010).

https://docs.google.com/file/d/0BzVIYTRbaNZwbzFObW5MMGZoeU0/edit

[KeithPickering]

Lerner wrote: Umm, can’t I speak for myself? and what is hakase? I asked for them in one document, chronologically or grouped by month. see first message in thread.No reason to create more work.
Thanks, Keith!

I have created an HTML document in Google Docs at https://docs.google.com/file/d/0BzVIYTRbaNZwUGxaeExIZkJhaE0/edit
The document has public permissions, so just grab it and put it where you like.

I’ve sorted the references by date, but conference papers generally have only a year, and I have put those at the top of a given year. Similarly, papers with a year and month but no day I have sorted to the top of the given month.

Visual inspection showed a handful of references returned by Inspec were not actually DPF references (generally astronomical plasma papers) which I deleted. The final version now has 69 references.

Finally, references returned by ISI have a DOI but no URL; references returned by Inspec have a URL (generally doi-like) but no actual DOI. I’ve put them both in the same field on the HTML table.

[KeithPickering]

zapkitty wrote:

So now I’ve got 84 citations, and the question is how to display them in a useful manner. Two options come to mind:

I [em]think[/em] that Lerner-hakase wanted these to go into the lists at DPF network?

http://denseplasmafocus.org/

… which has its own setup for listing cites.

Thanks for the link, but wow! A lot of work by hand, there, for 84 citations. Also, the “register” link is broken, as is the “login” link. So I’m thinking denseplasmafocus.org is not ready for Prime Time.

I’m willing to do the hand work if there’s no easier way … but here’s hoping there’s an easier way.

[KeithPickering]

OK, just back from the library. My Inspec search for “dense plasma focus” during 2010-2012 yielded 72 citations, which I downloaded in bibtex format. I did the identical search using ISI and got 31 citations; later inspection showed that 19 of these were duplicates from Inspec, while 12 were not found on Inspec (including a couple by LPP team members). So it’s definitely worth it to search ISI too.

So now I’ve got 84 citations, and the question is how to display them in a useful manner. Two options come to mind:

1. Just put them all in a big HTML table, all on one page. Rather long, but the page is searchable. I could do this by writing a perl script.
2. Create a bibliographic database using MySQL or similar, along with query and display screens using .php. This would require someone at your site with the time and expertise to do it. Or I could do it, but that would mean giving me access to your server for testing.

For now I’m proceeding with option 1. Let me know if you’d prefer option 2.

[KeithPickering]

Let me give it a shot before you spend anything.

My local university has Inspec. They have public computers in the library that should have access. Since Google Scholar lists 280 DPF papers since 2010, I assume the total number we’re talking about is manageable.

I’ll post my progress here.

[KeithPickering]

There are still a lot of unexplored possibilities if decaborane has unanticipated issues. Pentaborane, for example, is gaseous at room temperature.

[KeithPickering]

FoFu1 is a research device, not intended for power production. At the very low pressures inside the device, the problem is taking enough fuel out (prior to a shot), not putting it in.

[KeithPickering]

annodomini2 wrote:

FYI here are photos taken previously of an insulator, and one that appears to be damaged.

Remember that ‘secret’ insulator formulation? Starlite: http://www.telegraph.co.uk/technology/5158972/Starlite-the-nuclear-blast-defying-plastic-that-could-change-the-world.html

Might be worth seeing if Maurice Ward has finally broken down and filed a patent!

It’s a thermal insulator, no word on electrical properties.

I had never heard of the stuff, but the AWE test video shows that there is a lot of outgassing under thermal stress with this stuff. Not what we want.

[KeithPickering]

Wow. Could this be caused by expansion of a hot cathode? If that’s the case, some things to think about would be increasing the tolerance space between cathode and insulator, or increasing the tensile strength of the insulator (rather than flexural strength, as I had been assuming).

Or maybe this might be caused by arcing? In which case, dielectric strength might indeed be a consideration.

[KeithPickering]

Wow, you learn something new every day. 🙂 Based on their spec sheet, Ceralloy 147 looks like another interesting possibility to try. It seems to be stronger than alumina, but not as strong as Technox (both structurally, and dielectricly).

[KeithPickering]

benf wrote: Would Silicon Nitride be a possibility? It’s used in the Space Shuttle rocket motors. Here’s product description and spec sheet from Ceradyne and Wikipedia info.

Silicon nitride is a semiconductor, not a good choice for an insulator.

[KeithPickering]

Just to follow up, here’s a comparison of various grades of Technox vs. various grades of alumina

	Material:                          Technox 2000   Technox 3000      96% AlO3    99.5% AlO3

	Flexural strength (Kpsi)                   145            203           50         55   

	Compressive strength (Kpsi)                290            290          305        377

	Modulus of elasticity (Mpsi)                30             30         43.5       54.4

	Poisson ratio:                             .30            .30          .21        .22

	Fracture toughness (KIC)                    10             10          3.5          4

	

Dynex doesn’t give dielectric constants in its materials sheet, but http://iopscience.iop.org/0508-3443/18/6/305 indicates that zirconia has a dielectric constant of 22, while that of alumina is about 4.

[KeithPickering]

Physical strength, rather than dielectric strength, is the key. There are plenty of materials better than alumina from a dielectric standpoint, but you’d have to look long and hard to find anything stronger. And if breakage is the problem, that’s a tough nut to crack. In that regard it would be useful to know for sure the failure mode: flexural, tensile, or compressive. From the description above I’m guessing flexural, as the shots bend the “brim” of the hat (but I could be wrong). Macor, for example, has 3 times the dielectric strength as alumina, but only 1/4 the flexural strength. So if alumina is going to break under the stress, Macor will too.

In spite of asymmetric implosion’s comments, I’m thinking a zirconia ceramic may be the solution. Dynacer (http://www.dynacer.com/data_sheets.htm) has several grades of a zirconia ceramic they call Technox which has 3 to 4 times the flexural strength as alumina. Pure zirconia also beats alumina in dielectric resistance too. And like all ceramics it looks like it can be made into pretty much any shape.

[KeithPickering]

Maybe it’s 40 Watts over 17 years.

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