Fusor 2020

For posts specifically relating to fusor design, construction, and operation.
User avatar
Mark Rowley
Posts: 873
Joined: Sun Dec 29, 2002 5:20 am
Real name: Mark Rowley
Location: Sacramento California
Contact:

Re: Fusor 2020

Post by Mark Rowley » Tue Aug 25, 2020 9:42 pm

First run with the cooling maze was a resounding success. Following a 15 minute sustained run at a roughly estimated neutron TIER of 1.3E+6 it never peaked over 87F (30.5C). Cooling fluid was water with Rislone Hy-per Cool Super Coolant. As of now, the coolant is only recirculating within a 2 gallon reservoir with no radiators or extra cooling system. Adding a couple fan cooled computer-type radiators (as in Jon’s system) is something I’ll probably employ in the future.

In addition to these changes I opted to replace the Yellowjacket HVAC pump with a much quieter and more efficient Welch DuoSeal 1402. Being a higher capacity pump, it’ll rough down to almost 9mTorr in a couple minutes. The Yellowjacket could rough the system down to around 12-13 after about 5-10 minutes. Performance wise with the fusor it’s negligible but at least the lab is a once again a quiet place during operation.

One other bit of good news is the fact that I was able to keep the HDPE moderator in the exact configuration and distance as it was when BTI calibrated a month or so back. I’ll double check calibration in the next few days to see if the water in the two mazes have made any significant differences with moderation.

Mark Rowley

2A89E1B1-2ED2-4528-A3AA-9242B9811DFD.jpeg

User avatar
Richard Hull
Moderator
Posts: 13220
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: Fusor 2020

Post by Richard Hull » Wed Aug 26, 2020 4:13 am

Great report and I am glad you are running cool. I used a yellow Jacket from 1997-2003. It could hit 8 micros on fusor II , but with the increased volume in fusor III, it hit 10 or12 microns in a few minutes. Ultimately, like you, I swore off direct drives and went for the much more soothing lup-lup lup of a belt drive, slow winder. Great work.

The key is that, once calibrated, never move the moderator or significantly alter the positions of any major physical object around or near the moderator. Fusor IV was frozen in space 2004-2019. Right now, as I am un-calibrated I have complete freedom to just mess the entire system up and introduce or remove anything as it pleases me. I really do like this, as I can experiment and allow the 3He tell me whether I have made a quantitative improvement. With the silver activator buried in the moderator, I can always prove I am doing fusion over and above any questions regarding the 3He counter which we all know is showing fusion is taking place. Still.......Dead silver made radioactive in a few minutes always shuts up any doubters related to electronic neutron counting instrumentation. (Not that anyone has doubted the 3He heralding fusion.)

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.

User avatar
Mark Rowley
Posts: 873
Joined: Sun Dec 29, 2002 5:20 am
Real name: Mark Rowley
Location: Sacramento California
Contact:

Re: Fusor 2020

Post by Mark Rowley » Wed Aug 26, 2020 8:01 am

A very good point Richard. Totally plays into why I’m having so much fun with activation lately.

After a second test run this afternoon I noticed an annoying backscatter problem. Easily fixable but moderator configuration will undoubtedly get altered. If the aging BTI’s fail beforehand, I’ll be just as happy with activation numbers and gamma spec.

Mark Rowley

User avatar
Mark Rowley
Posts: 873
Joined: Sun Dec 29, 2002 5:20 am
Real name: Mark Rowley
Location: Sacramento California
Contact:

Re: Fusor 2020

Post by Mark Rowley » Sun Jun 20, 2021 5:32 am

Before resuming the BoT2021 project, I’ve decided to try something unique with this fusor.

Reviewing old disassembly photos from last year, I came across the beam impact “lozenge” images from the inside wall.

C35FB9A7-E9FD-47D9-9312-962B930B88EF.jpeg

The lozenges expectedly line up with each of the 6 “star mode” beam radials from the grid.

Since I’m making some deuterated titanium targets for the BoT2021 project, I figure I’ll try installing several in the fusor before it’s temporarily disassembled. Placement will be on the chamber wall in the same location as the lozenge impact marks where they will serve as deuterated targets.

If the ion beams have any type of BoT characteristics as indicated by fusors with cylindrical grids, this might result with a substantial increase in neutron production… or it just may fail miserably.

Either way, I’ll update with the results soon. And of course this is all incumbent on the success of the deuterizing apparatus.

viewtopic.php?t=14055

Mark Rowley

User avatar
Jim Kovalchick
Posts: 585
Joined: Thu Apr 14, 2011 12:00 am
Real name:

Re: Fusor 2020

Post by Jim Kovalchick » Sun Jun 20, 2021 12:21 pm

Mark,
I recommend using small Ti targets. I used large pieces of it in mine and found pressure control became difficult. I was also using a ring grid then, so perhaps your multi beam arrangement may help avoid big temperature induced pressure changes.

Jim K

User avatar
Richard Hull
Moderator
Posts: 13220
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: Fusor 2020

Post by Richard Hull » Sun Jun 20, 2021 2:42 pm

"Let the experiment be done" Benjamin Franklin

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.

User avatar
Mark Rowley
Posts: 873
Joined: Sun Dec 29, 2002 5:20 am
Real name: Mark Rowley
Location: Sacramento California
Contact:

Re: Fusor 2020

Post by Mark Rowley » Sun Jun 20, 2021 6:11 pm

Jim, definitely going small. The furnace will only host a maximum size of 15x40mm. I’ll be using 0.203mm sheet and each target will probably be 15mm sq, possibly smaller. Installation will utilize a simple slide-in low profile aluminum sleeve (or similar).

First run will probably utilize a single target. If it works, one would be sufficient to identify any positive results.

Mark Rowley

Post Reply

Return to “Fusor Construction & Operation (& FAQs)”