U fo Wisconsin fusor report

[Richard Hull]

Thanks to Richard Hester for posting the "additional fusor link" on the links forum. I printed out and read with great delight the October 2000 report on the Univ. of Wisconsin fusor effort. I highly suggest any avid fusioneer on this list go to the site and do the same.

It appears that they obtained about 10e7 neuts at 55kv@60ma for a power input of 3.3kw. With a moderate production of 10e5 neutrons at 400 watts, The Hull/Zambelli fusor systems fall in the zone of credibility. Not only has our instrumentation and technique been proven good, but results from our fusors are in line with high level institutional results. While to many this may seem expected, amateurs are often treated as such and their results often viewed with suspicion. Not so in this case. All amateurs working on simple neutron producing fusors with decent equipment and using moderate skills, WILL do fusion!

Some intersting results of the paper were noted. The shocker was that the collisional core WAS NOT the main source of fusion within the fusor!!!!!!!! Instead, the fast deuteron, fast neutral collisions in the inter-grid region are supposedly the main source of fusions in the system.... (many, many more of 'em happening, even if they are not an ideal case of high cross section). Important finding if warranted to be true.

Another nice finding is that at the magic 60kv level, D-3He fusion starts looking better than D-D fusion! Most amateurs will never hit 60kv at the current level of 70ma (4200 watts), but if we do, some really big bucks are going to have to be rolled out to purchase 3He inorder to continue to play with the big boys. I always realized that over 100kv applied, D-D was a losing battle. What I didn't realize was that D-3He exceeded D-D at as low a figure as 60kev.

This is another bummer for amateur fusion in that we can only really hope to play on the lower cusp of fusion without deep pockets, a rich uncle, or a scientific gas company sponsorship. I am ready and willing, like a NASCAR racer, to plaster big advertising logo stickers all over the body of my fusor like "Powered by Matheson Gas"...."Vacuum by Lesker", etc., in exchange for free product.

Too bad that D-T is just not an option for us. We would be doing 10e8 NOW in junk amateur devices at 30kv!! Wisconsin would be at 10e10!!!

Nice work by a well funded and dedication institution.

Richard Hull

[guest]

How much is a lecture bottle of 3he ?

[r_c_edgar]

If I recall, 3He is currently valued at over $1000/gram. I don't know exactly how much that would put a lecture bottle at, but I'm pretty sure it will fall into the category of 'too much' for most amateurs.

--Ryan Edgar

[Richard Hull]

I am moving the He3 commentary to the construction site which is where it would be searched. I will research pricing.

Comments on the U of Wisc. work can continue here as it is general fusion and theory discussion.

Richard Hull

[guest]

Hey Richard:

We can still beat them at their own game.
Remember my post about altering the fuel mixture.
If neutrals do the trick then the findings of Plasma Focus people about mixing in a little argon might be worth a try.
I went the high power pulse route due to costs of alternate fuels... Aneutronic research is not new... just very costly. The University of Texas had the stuff hanging around because they had dilution refrigerators.. We got what boiled away. I bet you could find a school that does ultra low temp work thats just venting the stuff to the atmosphere.

Larry Leins
Physics Teacher

[Richard Hull]

Woaa there....

Argon???!!!

There still remains such a thing as cross section at given energies!

Argon-deuteron fusion???!!!

I don't think so...........

In the Helium3- deuteron scenario, there was always a modestly poor cross section at the lower energies. Add to that the fact that fusion done by banging neutrals against hot ions is a statistically rare thing until the hot ion is really moving (really hot) and you have a marginal system under 40kev with D-3He.

Some High Z element like argon has close to zero chance of fusing even at 1++ megavolt applied!!!

Any genuine fusion recorded in a fusor relying on the D-A reaction is simply D-D fusion and D-D fusion alone.

Nice thought, but a bit beyond dreamland.

Richard Hull

[guest]

Could someone explain to me why D-D fusion is less likely at 100 Kev than 30 or 60 Kev. Looking at the cross sections for this reaction, the cross section appears to max out at around 1 Mev. It seems like the higher the voltage the more efficient the reaction should be.

thanks

[Richard Hull]

Bob,

D-D fusion will continue to grow to about 1 mev as you state. However this discussion started talking aobut how D-3He fusion beat out D-D at 60kv. (the cross section curves intersected there). From 60kv on up, the D-3He reaction was better (more fusions per unit increase in voltage than D-D.) As I noted in one of my posts, D-D WILL get better and better out to 1 megavolt, but not as fast or a good as D-3He after 60kv.

If any amateur ever hits 100kv applied, (unlikely), he or she might figure on going to D-He regardless of the expense. After 100kv They would be just pouring in more voltage for marginal returns in D-D.

Richard Hull

[guest]

Not to fuse but be something to bang against.
Neutron stripper reactions.
Heavy ion fusion does occur tho,,,,,
argon whammed into thorium makes plute at 40mev!

[guest]

Richard, thanks for the clarification. I try and catch most of the posts but there is a lot out there!

[ijv]

I'm a bit confused by the voltage levels you were quoting Richard, could you clarify a bit.

When you say that the report shows at 60 kV D-He3 fusion is more reactive than D-D, which results are you referring to?.

From Fig. 2 the D-He3 curve crosses over at about 45 kV, but thats for ions only. For CX D-D & CX D-He3, the curves won't cross to well over 60 kV (off the end of the graph.

Later on in the report in Fig. 9 there is a graph of proton poduction rates for D-D & D-He3. The D-He3 rate is climbing more steeply than the D-D, but the graph only goes out to 55kV (extrapolating out the curves could cross at around 60kV though)

Also, how does the graphs in this report tie in with the relatively well know reactivity chart in
http://silver.neep.wisc.edu/~neep533/LEC24/32slide.html

On this chart D-He3 reactivity is greater than D-D at only about 15kV (I assume that the horizontal axes are reffering to the same quantity).

Thanks for any light that anyone can throw on this.

[Richard Hull]

The figure #2 actually does show the theoretical reaction rates for D+D and D+3He crossing at or about 43kv with the D+3He winning. (left most two curves on the graph) This graph is, however, theoretical and based on calculations, not on any empirical experiment they performed.

Figure 9 is based on data actually taken. It shows a steeper rate for D+3He and a bit of interpolation put this actual crossing more out near 65kv applied. Plus, in the body of the paper, (Experimental Results), they state that at high energies the cross section of D+3He exceeds D+D.

It is intersting to note that they use "reaction rates" (mev/cm^2sec) as opposed to cross section in some of their graphs. This calulated, and sometimes empirically supported usage, they say, reflects more realistically the fuctioning of the IEC fusion over the classically heated hot ion fusion in the maxwellian.

So, I am under the opinion, based on their data and empirical graphic representation, that the fusion rate for D+He3 will indeed beat out D+D at some voltage around 65 kv applied IN THEIR DEVICE. This jibes with the cross sectional data, but empirically is seen to be delayed a bit beyond the theoretical cross sectional 43kv cross over. This may be due to the fast neutral-hot ion fusion polution in the process admitted to in their paper.

Richard Hull

[ijv]

Thanks for that Richard.

Are the results you are getting out of your setup directly comparable to the UofW data for D-D fusion?. If so how does it compare. You have mentioned some spot values, I am wondering about the trend in this case.