Monday, March 21, 2011

Fusion Achieved

Since I have last written, I have done much work on the reactor, including the addition of a new mounting system, based upon an old scroll saw stand, and the completion of the deuterium system. Also, the neutron detection system was completed.

Here is a picture of the full reactor.
The new detection system utilizes a boron-10 lined proportional tube, which can detect thermal neutrons, however, the neutrons from the D+D -> He-3 + n reaction have very high energies, and therefore must have their energy reduced prior to entering the tube. Therefore, the tube is placed inside a HDPE neutron moderator, which reduces neutron energy through elastic collisions with protons inside the moderator. The tube is read by a Ludlum Model-3.

I eventually fired the reactor up and did some trials with the gas system. My data indicates that the reactor does indeed work!


Due to the lack of the increase between tests 2 (background, unmoderated) and 3 (reactor on, unmoderated), it can be known that the tube was not detecting x-rays or EMI from the fusor, and that any recorded count would be due to neutrons.
The following three tests, (4-6, reactor on, moderated) show a large increase over background, indicating that the reactor was indeed producing a measurable neutron flux, and was indeed working!

I entered the reactor, with this simple experiment into the science fair, and I won both the district and regional fairs, and because of this, I will be attending the Intel International Science and Engineering fair in LA!
What's Next?

I am in the process of rebuilding the gas system to allow for lower leak rates, and hence higher deuterium purity, this should allow for substantially higher neutron fluxes. Additionally, I am developing a penning type ion source, which will be added to the reactor and will allow it to operate at lower pressure with greater stability. Also, I may move the reactor to a new, recently acquired chamber with an exceptionally low leak rate, and a water cooling jacket.
And finally, some pictures of the reactor