Fusor Forums

Cleaned things up somewhat, and got more beam out - going to keep dialing it in.

RT

Dialded in on H mode, and am pulling proper beam now. Some pics and videos of operation:

https://youtu.be/Jx0ts2VmjHs

https://youtu.be/mu_XNZKC0aw

RT

Robert,

Now this is a really cool project! I've watched this thread with great interest. Is the Northwest Nuclear Consortium open to visitors?

I'm trying to pull together a midwest conference for fusor.net members (viewtopic.php?f=47&t=11408). I know you are well outside the midwest but do you ever travel to this area? You would certainly be welcome as a guest speaker.

Thanks Garrett,

With regards to the invite out east, thanks also. I can't say I'm out there very often, but I'm likely to be at HEAS this year, I'll be certain to say hello if I see you there.

I haven't been affiliated with NWNC for several years, and admins haven't been responsive to my request to edit the thread of it's mention. The system resides with me now, as it should.

RT

Understood. I was really interested in seeing your device first hand and discussing ideas. Hopefully I'll be at HEAS this year.

You're welcome to drop by Seattle sometime and see it, it's in my living room. Otherwise wait about a year and visit the Philippines as I'll be there studying abroad for a few years and my most of my hardware but for the most extreme of export restricted materials will come with. My couch there will be open to to surfing, unless I'm out surfing.

Robert,

Can you elaborate more on the physics of plasma going into "H" mode?

I have seen this phenomenon myself or at least something similar while playing around with an induction coil and a neon tube, as the neon tube was held close to a high frequency induction coil the tube lights up but at some point the plasma goes from being just normal "neon tube bright" to something more like a flash bulb. The transition was rapid, and within seconds it melted the glass and vented the neon tube.

Steven

Steve- Here's a paper that works out the transition point:
http://iopscience.iop.org/article/10.10 ... 21/014/pdf

Jake,

Thanks, read the abstract, but the rest of it is behind a pay wall, so it's inaccessible to me unless I pay $33.

Steven

Here you go, Steven.

http://sci-hub.cc/http://iopscience.iop ... 21/014/pdf

Gave a thin film titanium coated copper target a beating last night. It puked a meganeut or so at 50kV after effectively instantly loading. Wasn't a lot left of it when I pulled it out for a look at the damage. Good stuff!

Also attaching a video, a few photos, and a cool .gif of the focal spot adjusting at lower power. First one's the gif.

https://youtu.be/jLvlHaeXsss

Robert,

Excellent as always! How thick was your Titanium coating, and are you currently cooling your target?

Bruce

You can really see the secondary electrons hitting the viewport, a magnet might work to deflect them.
What's the x-ray dose rate at the viewport?

I just finised work on my new SSPA with 1kW to drive my plasma heating.
Attached you see the numbers (going up to 850W) and a nice picture of the device.
The short video shows the very first test without adjusting the tuner - so you see almost the same power reflected as going out. The sound gives you an idea of the powersupply needed for this!! Unfortunatly the file was not uploaded due to a mp4-restriction.

@Robert: I did not see any RF-discharges in the tuner - as you did. What power levels did you reach when these issues occured?

BR,
Werner

Werner
Nice to see you using the W6PQL kits for the SSPA.
You can see my build on https://www.qrz.com/db/ZL2TUD

@John: You are right! But I did not use the controlling boards. The reason for choosing the BLF188XR was its robustness versus Price. The right device for a plasma generator! Are you also going to use it for this purpose - or just for ham?
I just read that you are very good in designing RF devices: I still do not know how to design the antenna for the plasma. My first idea was just trying to use a copper pipe with 14 turns and give it a try - using the tuner. I also thought about calculating a kind of resonance frequency resulting out of the geometry – but did not succeed. Next try was to use a spectrum analyzer with a VSWR bridge to measure the resonance frequency - did not work. What do you think will be the right way to focus on – from your experience?

BR,
Werner

Werner
we should transfer this to a new post so as to not dilute the good work of Robert Tubbs
I'll start a new post under ion sources to answer this

Hi Robert,
Please, comment about the RF power on your Ion Source Inductively Coupled as well as the Proton/Deuteron current.
Could you provide some diagram of your source? I am curious about the three extractors electrodes.
Thanks!
Roberto