Progress Update

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Joe Gayo
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Re: Progress Update

Post by Joe Gayo »

Good catch, it was a typo. The post is now corrected. However, the ion source was misaligned for both of the two calibration runs. Taking new data now, and WOW! I'll post results soon.

The cathode current is a function of the ion current. It's higher than the ion source current because of secondary electron emission. There is no gas discharge in the main chamber. The camera looking through the viewport just sees a faint blue glow from electrons hitting the glass feedthrough. (And speckles from x-rays of course)

Thanks.
Last edited by Joe Gayo on Mon Dec 21, 2020 4:20 am, edited 1 time in total.
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Joe Gayo
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Re: Progress Update

Post by Joe Gayo »

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Joe Gayo
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Re: Progress Update

Post by Joe Gayo »

85kV, 180uA, 261k CPM!
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Joe Gayo
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Re: Progress Update

Post by Joe Gayo »

90kV, 190uA, 292k CPM!!
JoeBallantyne
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Re: Progress Update

Post by JoeBallantyne »

1.2E+7 n/sec (your last run) is doing VERY well indeed.

What pressure are you running at? If there is no plasma glow at all, I expect you are running at much lower pressures than pretty much everyone else here.

Joe.
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Richard Hull
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Re: Progress Update

Post by Richard Hull »

Once the voltages get high, the current becomes much less. This is seen in all the mid sixties Farnsworth effort with the cave fusor. Lower pressures 2 microns and just a few hundreds of microamps to 2 ma max. I refer to this as "clean operation". Rarely seen in amateur work. Still, there is always a limit that keeps the fusor either simple or complex from significant return on invested energy.

Joe, Thanks for the tube info. I will have pull my tube out of storage and photograph it. Most BF3 tubes are at 76cm or 1atm with a less than 1atm fill of BF3 and the remainder a backfill of argon.

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
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Mark Rowley
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Re: Progress Update

Post by Mark Rowley »

Joe, I noticed similar results when I operated between 50-67kV. When wall loading was optimal all I needed was 1.5 to 2mA to get some really nice numbers.

67kV was my ceiling. Doubtful I’ll be able to get beyond that anytime soon.

Mark Rowley
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Joe Gayo
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Re: Progress Update

Post by Joe Gayo »

The chamber pressure is 1.5E-5 Torr typically during operation.

Just as a interesting side note, the results were seen immediately and no wall loading or "conditioning" was required.

I will be installing my 125kV power supply in the next few weeks. In addition, I have about a factor of 10 in ion current left to increase.

I would like to be the first amateur to reach 1E+8 n/sec.
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Scott Moroch
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Re: Progress Update

Post by Scott Moroch »

Joe,

Very nice setup. What type of ion source are you using?

Thanks!

-Scott
"In the middle of difficulty lies opportunity"
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Jon Rosenstiel
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Re: Progress Update

Post by Jon Rosenstiel »

Joe,

Love your setup, and your hv-feedthrough. Guess I'm going to have to go that route too. Keep up the good work.
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Joe Gayo
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Re: Progress Update

Post by Joe Gayo »

@Scott

The ion source is a simple discharge source that's been cobbled together, nothing special

@Jon

Thanks. Nice work on the Co-60!
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Joe Gayo
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Re: Progress Update

Post by Joe Gayo »

Operational tuning (pressure, etc.) has resulted in a dramatic improvement. 100kV, 200uA ion, 2.5 mA cathode, 2 E-5 Torr, 654359 CPM
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Richard Hull
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Re: Progress Update

Post by Richard Hull »

Great Joe! You are the first to report 100kv results. X-rays gotta' be a killer....Thank goodness the current is low.
I promised an image of my BF3 tube and here it is. the lab was at 33 deg F.

Richard Hull
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3He - BF3 Anno.jpg
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
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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