Thursday, June 28, 2007

Reactor Building and Reactor Controls

I have been thinking about a reactor building. Hexagon or octagon? I lean towards octagon. Open top cell. I'll have to look at gamma ray "sky" factor scattering to see if that is a problem. An open top would make it easier to string unanticipated wires or pipes.

I'm thinking partial shield at this time. I think that would be OK since I'm contemplating a switch gear yard to one side of the building. That would allow a truck entrance from the switch gear side. I'd rather not have to crane in the heavy stuff. Forklifts and rollers. Also we are going to have to put an LN2 tank in there some where.

For viewing during operation I'm thinking one periscope - very simple design and only for confidence. Plus multiple video cameras. Cameras will each have their own video cable and control wiring.

I have been giving the bus question some thought. I think Ethernet for data collection and CAN for control. A PC104 system for control spots. Wireless will not be used for any functions. An isolated (to 100KV) 24 VDC supply and back up battery will be used for incidental power and control an the high voltage side. Isolation from the low voltage side will be handled by transformers for power and fiber optics for data.

Safety controls (master breaker trip etc.) will be hard wired as well as computer controlled.

Wednesday, June 27, 2007

HV Power Conversion

Light Triggered SCRs [pdf] an overview.

Power Conversion a book (the above link is an excerpt.

Eupec Information - semiconductors.

GvA-leistungselektronik power semiconductors and modules.

Monograph - Light triggered SCRs 8kV [pdf] used in Celilo Converter Station of the Pacific Northwest-Southwest HVDC Intertie by Bonneville Power Administration in Portland/Oregon/USA.

Magnet Power Supplies

My plan for the magnet power supplies (100V, 1,000A max) is to use an induction heating power supply to supply the power and use a ferrite transformer for voltage isolation. Followed by rectification and filtering.

Some candidates for the induction heating supply can be found at: Induction heating power supplies.

Since supplies of up to 1.5 MW are standard it may be a good way to develop the high voltage as well.

Funding the Polywell

Any ideas?

Open Thread #1

Have at it.

Sunday, June 24, 2007

LN2 Storage

LN2 storage tank should have 10 minutes of operation at .45 T magnet intensity. Capability to install a larger tank as experiments warrant.

Storage at 150 psig except when operating reactor then storage will be at 0 psig. Liquid level measurement will be a differential pressure gauge on the pump inlet standpipe (safety).

Total liquid level measurement will be a teflon insulated probe capacitance measurement. The probe will extend through the tank and down the standpipe to near the pump inlet level.

LN2 flow calculator

Reactor Vessel Rqmts.

Here are some random points on reactor vessel rqmts. This will get expanded as we get deeper into the problem. Save this page periodically if you want a history.

View ports
Pump ports
Gas Analyzer port
Laser Analyzer ports - Thompson Scattering Tomography
Plasma Analyzer port
Electron gun port

Vacuum Pressure measuring port with various instruments to cover the whole range.
Vessel temperature monitoring
12 LN2 connections (2 per coil)
Inlet pressure monitoring of LN2
Outlet pressure monitoring of LN2
Inlet temperature monitoring of LN2
Outlet temperature monitoring of LN2
12 HV/Coil current connections (rated to 100 KV if possible used to 75 KV) 1,000 Amps max. continuous. (pulsed higher).

Sunday, June 17, 2007

WB7x Design Issues

Here is my prelim list which gives kind of a broad outline of some of the design issues for WB-7x. This is a strictly first pass effort and is as of yet no where near exhaustive. If you have comments post them.

Power supplies:

Three Alternative Grid supplies
Grid Power 0 - 70KV ~10V steps Capable of modulation @ 10KHz (+/- 5KVpk) for power control 25A continuous. 50A for 3 seconds at reduced or zero modulation due to core saturation (if transformer modulation is used).

Grid Power 0 - 35KV ~5V steps Capable of modulation @ 10KHz (+/- 5KVpk) for reactor power control. 15A continuous. 30A for 3 seconds at reduced or zero modulation due to core saturation (if transformer modulation is used).

Grid Power 0 - 17.5KV ~2.5V steps Capable of modulation @ 10KHz (+/- 2.5KVpk) for reactor power control. 6A continuous. 12A for 3 seconds at reduced or zero modulation due to core saturation (if transformer modulation is used).

PID control designed to keep the Modulation Transformer (if used) unsaturated. Or can be operated open loop.

Ripple less than 100 V at operating current. (that is going to be tough except at high frequencies). Ripple is bad because it spreads the energy.


Magnet power Isolated from Ground to 100 KV
Vacuum Pump Power
Electron gun filament supplies
Electron gun power supplies
Electron gun grid control
24 VDC isolated to 100 KV for the high power control bus rqmts. 1 KW (could be less)
120/240VAC 60Hz 10 KW .6 PF isolated to 100 KV for misc. reactor rqmts

Reaction Control Points:
Coil current
Magnetic Grid Voltage
D-D pressure (will be used to control H in pB11 reaction)
D-D valving (will be used to control H in pB11 reaction)
Vacuum Pump power control
B11 injection control
Electron gun controls

Residual Gas Analyzer
Data Collection and control computer
Coil outlet temperatures
Coil LN2 manifold temperature
Coil LN2 flow rates
Coil current
Laser diagnostics
Neutron counters
Gama counters
Radiation survey instruments
Health physics

Calibration/Quality control materials/data:
Lab Clock for event synchronization

Test procedures:
Item qualifications
System Quals
Reactor Tests

Reactor Systems:
Magnet System
Vacuum Systems
Grid Voltage
HV Safety
LN2 Safety
Coil Energy Safety

Control Bus Issues
Reaction time
Radiation hardness
I like CAN bus for control however, I'm open to suggestions.
No wireless. No crash buses i.e. Ethernet (except for data collection).
Stuff that has to fail safe will be on CAN.

Labratory Procedures
Health Physics
First Aid

Labratory Infrastructure
Shop Air
Chilled Water

Update: 28 June 007 2031z
Labratory Infrastructure added
Update: 30 June 007 0536z
Electron gun stuff added

Friday, June 15, 2007

CAD Drafting Programs

Over at the IEC Fusion Newsgroup and also at the NASA Space Flight Forum I'm looking into the design of a test reactor with the following specifications.

Do we have enough expertise here to design WB-7x ?

Here is my general specification: LN2 cooled truncated cube coil configuration. Minimum size feasible for coil of reasonable dimensions and cost. 60 KV driver supply 10A, 100 V ripple maximum (10V much better). Capable of moderate levels of modulation (+/- 2 to 5 KV at 10 KHz) Vacuum pumps capable of 12 hr draw down or better. Vacuum chamber custom designed for coils and insulators. Updated 23 June 007: 75 KV driver capable of 25 Amps. Alternatives: (provision needs to be made in the lab to install bigger power supplies if a smaller one is chosen) 40 KV at 13 Amps. 20 KV at 7 amps.

My ideal would be a D-D Polywell - LN2 cooled magnets - well radiation shielded and instrumented - laser diagnostics - run continuously in an automated data collection mode for runs of at least a few minutes and preferably an hour at a time. HV power supply of 75KV so low levels of p-B11 fusion can be done. There is a p-B11 resonance that needs to be explored that is in that region. If the power density was sufficient in that region it could be a big advantage Bremms wise. The fusion cross section peaks at .1 barns there.

An electrostatically or piezoelectrically operated gas injection valve must be designed. B11 injection needs to be figured out. Decaborane might be the answer from a safety perspective. It boils at 213 C. Electrically heat a container of it to maintain a certain gas pressure and then valve it. Or perhaps a boron block heated by an electron beam or laser.

From the wiki on Decaborane:

In aneutronic fusion research, decaborane is used to boronize the tokamak plasma to research the proton-11Boron reactions.

All very interesting. However, what I want to do is suggest a CAD drafting program for use in the above project. First off the price must be zero for a 2D version. Upgrades to a full 3D engineering version must be reasonable. The 2 D version must not be in any way crippled. It must be easy to learn.

I have settled on Solid Edge Free 2D drafting package for now. I'm going to test it and see if there are any problems. If so I will report back. If not I will report that. Expect news in a day or less.

Any comments or suggestions would be appreciated.

Solid Edge Testimonial

Monday, June 11, 2007

Change The World In Three Minutes

Dr. Robert Bussard talks about how to change the world and it only takes three minutes.

For a deeper look at this technology:

Bussard Fusion Reactor

The video at this one is deep on physics and lasts an hour and a half, however the last 30 minutes has the implications. The three minute video is excerpted from this longer version:
Easy Low Cost No Radiation Fusion

IEC Fusion Newsgroup
IEC Fusion Technology

Wednesday, June 6, 2007

Geometric Solids

Dr. Bussard says that the number of edges meeting at any vertex must be an even number for optimum operation of the magnetic grid.

Here are some candidate solids you can play with

The Rhombitruncated Cubeoctahedron

The Rhombicosidodecahedron

The Rhombicosidodecahedron

The Rhombicubeoctahedron

The Icosidodecahedron

The Cubeoctahedron

The Octahedron

Or you can go to the main page and look at different solids. The indivildual geometry pages I have given are Java applets. If that doesn't work for you the main page also has them in VRML.

Sunday, June 3, 2007

Feynman Lectures

Here is a link to some lectures on physics by Nobel Winner Richard Feynman. If the chunks are too long for you or you don't have the right video player Lubos Motl has some links to the whole thing segmented in shorter clips.

Feynman is very wise to do what I normally do. When he needs mathematics done he leaves it to mathematicians (which in some cases is Feynman himself). So to get these lectures may be conceptually difficult, however they will not be mathematically difficult. For those of you math challenged, no worries, mate.

Saturday, June 2, 2007

Electron Circulation in Cubic Polywell

Here is the full page version which has much better resolution.

Let me add that it was done by Indrek.