Fusion Message Board

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Subject: 100K Neutrons!!!
Date: Jan 02, 4:15 pm
Poster: Richard Hull

On Jan 02, 4:15 pm, Richard Hull wrote:

I what is the finest and most productive run to date, Fusor III pushed over the 100,000 neutrons/second mark.

I have removed the entire fusor from the original frame work and set aside an entire bench area in my lab with 3 vertical tiers of 2X8 feet for permenant fusor operations with all pumps, gas manifolds, power supplies and plumbing for same. The new arrangement treats the fusor as part of a system rather than a system itself as in the frame model. This allows all components to be swapped out upgraded and repaired much easier than with the frame model. Thus, I am now working with about 48 square feet of surface area devoted 100% to fusor operations.

The key to this success is the upgrade of the power supply to over 35KV @ 3.5KW! Also, all the vacuum hardware was Stainless Steel and the only rubber hose was a short 6" section between the pump and the first SS control valve. The total vacuum path was cut in half! This lowered the conductance considerably. BOY it makes a difference! The gas handling apparatus was streamlined and all swagelock conponets were used.

The super number of neuts was achieved after a complete bakeout of the micromaze and about 3 hours of pumping. I now have two neutron counters! The superior and quanitative BC-720 detector and a factory victoreen BF3 neutron detector.

The fidgeting took about 30 minutes to find the sweet spot. With flowing D2 and the supply set to 29kv and 15 ma, the grid was nearly white hot! The 13 star rays were as sharp as if drawn. The Victoreen BF3 unit is used to tell when neuts are going. The audio level is set to max and normally you will here about 1 click every 5 minutes. (the monster has a 30 lb 10" diameter sold UHMW PE cylinder in which the BF3 sits to moderate the fast neuts.

At the height of activity the victoreen was popping away at about 3-4 snaps per second 2 feet away. (this is a 3 mrem neutron field!) The HP counter hooked to the BC-720 detector was advancing far more rapidly than in the past and I knew this was a special run.

The session ended early 8 minute run when the long lasting Tantalum grid collapsed. The clock was stopped and the necesary calcs showed that I had made and average of 113,800 neutrons/ second!!

A record for fusor III. I must now repair the fusor with a more robust Ta grid structure.

Richard Hull