Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Current images of fusor efforts, components, etc. Try to continuously update from your name, a current photo using edit function. Title post with your name once only. Change image and text as needed. See first posting for details.
RobertTubbs
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Re: Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Post by RobertTubbs » Mon May 08, 2017 7:13 pm

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
20170507_004519_1.gif
20170508_011723.jpg
20170508_000633.jpg

Bruce Meagher
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Re: Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Post by Bruce Meagher » Fri May 12, 2017 9:30 pm

Robert,

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

Bruce

Andrew Seltzman
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Re: Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Post by Andrew Seltzman » Sat May 13, 2017 5:08 am

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?
Andrew Seltzman
www.rtftechnologies.org

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Werner Engel
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Re: Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Post by Werner Engel » Mon May 22, 2017 5:38 pm

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
Attachments
1kW SSPA with filter and bias-PS in RF tight casing _almost finished.jpg
Amp Test for plasma heating.pdf
(340.44 KiB) Downloaded 81 times

John Futter
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Re: Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Post by John Futter » Mon May 22, 2017 7:12 pm

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

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Werner Engel
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Re: Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Post by Werner Engel » Tue May 23, 2017 4:49 pm

RF Coil with CF flanges.JPG
The first prototype of the RF-coil
@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

John Futter
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Re: Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Post by John Futter » Tue May 23, 2017 7:10 pm

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

Roberto Ferrari
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Re: Tubbs Beam-on-Target Effort [Neuts/Pics/Tips]

Post by Roberto Ferrari » Wed Jul 18, 2018 8:38 pm

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

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