Inner grid size assessment

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Harry Dixon
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Inner grid size assessment

Post by Harry Dixon » Mon May 21, 2018 1:18 am

Hello fusor.net,

As my team begin to start designing our first star-mode fusor, I wanted to get a few things straight about the inner grid.

I was wondering if anyone has ever made a study where they assessed what inner grid diameter would produce the largest number of fusion reactions with a constant amount of deuterium gas.

Harry Dixon

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Richard Hull
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Re: Inner grid size assessment

Post by Richard Hull » Mon May 21, 2018 6:08 am

No, no such experiments have even taken place, here.

There are 2 or 3 FAQs dealing with grid materials, construction and sizing, based solely on typical proven functional successes.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Dan Knapp
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Re: Inner grid size assessment

Post by Dan Knapp » Mon May 21, 2018 2:20 pm

There is some discussion of the relative size of cathode grid to anode diameter in the chapter on grids in the book:
Inertial Electrostatic Confinement (IEC) Fusion: Fundamentals and Applications
by George H. Miley and S. Krupakar Murali

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Bob Reite
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Re: Inner grid size assessment

Post by Bob Reite » Wed May 23, 2018 2:45 am

Oh I remember Doug Coulter finding that a grid half the diameter gave him more neutrons. Not double as I recall, but statistically significant.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.

Ameen Aydan
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Re: Inner grid size assessment

Post by Ameen Aydan » Fri Jun 01, 2018 7:10 pm

Where can you get that book about IEC fusion. I don't have $120 laying around, so if you could share maybe that could help? thank you!

Dan Knapp
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Re: Inner grid size assessment

Post by Dan Knapp » Fri Jun 01, 2018 8:57 pm

Ask your library to borrow a copy for you on interlibrary loan. You can buy a copy of the relevant chapter (Effect of Grid Geometry on IEC Performance) on the Springer web site for $29.95. If you attend a school whose library subscribes to the Springer book series, you can download a pdf copy of the book, or you can buy a paperback "mycopy" version (black and white; no color pictures) for $29.95.

Dan Knapp
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Re: Inner grid size assessment

Post by Dan Knapp » Fri Jun 01, 2018 9:26 pm

Out of curiosity, I did a web search to see if the book might be available anywhere else. Amazon will rent you a Kindle version for as little as $22 (price depends upon how long you can use it). There are several questionable web sites that claim they have it available for free download, but you use these at your own risk. Your best bet is to try your library first. In the age of electronic media, we tend to forget that there is still a lot of useful information in book form, and we tend to forget that there is this old thing called a library that has books on shelves and will borrow books for you from other libraries. Use it while you can, for libraries are on the decline. My university library just put the last of their hard copy books and journals up for auction sale. We have a problem looming when publishers go out of business and their electronic online journal files disappear. I hope someone is archiving electronic journal files. I heard at one time that Google was going to do this, but I haven't heard anything recently on it.

Rex Allers
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Re: Inner grid size assessment

Post by Rex Allers » Sat Jun 02, 2018 12:43 am

(Psst. --- Shssssh. --- Don't tell anyone.)

I didn't expect much but tried my searching-foo and *Wow* had big success. Somehow I found myself to page with a big cache of IEC-Fusion document files.
https://archive.org/details/IECFusionReactors

At the top is a list of 31 documents and #11 is the book Dan mentioned. To get them I clicked PDF in the download options at the right column. It let me download a 50 Mb zip file containing all 31 files as PDFs. A quick look at just that one file, it appears to be complete, 415 pages. Even searchable and with figures, diagrams, tables, and clear equations.

A great wealth of info. Unexpected.
Rex Allers

Ameen Aydan
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Re: Inner grid size assessment

Post by Ameen Aydan » Sat Jun 02, 2018 12:48 am

thank you so much. I did not know of any sources (except for this website) about IEC fusion or fusion alone. This is a great help. Thank you so much!

Rex Allers
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Re: Inner grid size assessment

Post by Rex Allers » Sat Jun 02, 2018 4:47 am

Adding a bit more about that zip of PDFs related to IECF that I found. No idea who put it together or if there are any ownership issues on the documents.

Here's the list of files in it:
1 ACT _ ESA - Advanced Propulsion Review IEC Thrusters
2 Critique of IEC Fusion Systems 1991 - 31763419-MIT
3 Deuterium Fusion Using IEC - kovalchick
4 EKXL Poisson Solver for IEC Systems - a257644
5 Easy to Build IEC Fusor - Hull
6 Fusion in a Magnetically-Shielded-Grid IEC Device 1510.01788v1
7 IEC Actively Colled Grids - seltzman_andrew_h_200805_phys
8 IEC Devices for Satellite Propulsion 07-Murali Presentation
9 IEC Dipole Assisted 2005 Presentation
10 IEC Driven Subcritical Fission Reactor - 80
11 IEC Fusion - George_H_Miley_S_Krupakar_Murali_(authors)_Iner(BookZZorg)
12 IEC Fusion Thruster manuscript_Becnel_02798
13 IEC Fusion in Japan - Stark Effect and Laser Enhancement
14 IEC Improvement ORNL - 158
15 IEC Neutron Generator Modeling - Bromley
16 IEC as a Power Source for Propulsion - 19930022121
17 IEC for Spacecraft FPPG_Poster_2006
18 IEC of Fusion Plasma with Grids - 11 Nadler
19 Improving Confinement in IED for Space - PhD-2007-DietrichCarl
20 Inertial electrostatic confinement fusion - US Patent 7550741
21 InertialelectrostaticconfinementWikipedia
22 K_Murali-IEC_Based_Compact_X-ray_Source
23 Magnetic Electrostatic Plasma Confinement
24 Multiple potential well structure in inertial electrostatic confinement devices
25 N and P Production Rate in Spherical Plasmas - jpfrs2004_06-731
26 Philo Farnsworth_ Fusor (Inertial Electrostatic Confinement)
27 Plasma jet source using an inertial electrostatic confinement discharge plasma US6121569
28 The Farnsworth-Hirsch Fusor - 634fusor
29 The Worlds Simplest Fusion Reactor - Ligon-QED-IE
30 Tips for IEC Investigators - FUSORTIP
31 magnetic-electrostatic-plasma-confinement
------
The publication that Dan mentioned is #11. That is what caused me to find this archive this afternoon.

Taking a quick scan of all the files contained, fusor.net and its members are well represented. Names I recognize and associated file-list numbers:
R. Hull -- 5, 26, 28
A. Seltzman -- 7
F. Sanns -- 20
J. Kovalchick - 3

In #3 there are acknowledgements of many other members and the forum.

Apologies if I missed anyone else from here in the list. I did no work except find the zip today. Hope the files in it don't ruffle any feathers here.

Some of the Richard Hull stuff is interesting early papers.
Rex Allers

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